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Kenneth Myers, MD; Terry Devine, MD;
Christen Barras, MD; Greg Self, MD
Departments of Vascular Surgery,
Centre and Epworth Hospital, Melbourne, Australia
This presentation explores current knowledge about the epidemiology of abdominal aortic aneurysms (AAAs) and their treatment by observation, open surgical repair or endoluminal grafting (ELG). It is illustrated by experience with 187 patients treated by ELG in our unit in Melbourne, Australia
1. THE NATURAL HISTORY AND RISK OF RUPTURE FOR AAAs
Active treatment is justified only if the risk from intervention is substantially less than for observation. Risks for aneurysm rupture must outweigh the risks from surgical repair. Single-centre studies provide information about the aetiology, natural history and management options, but much more has now been learned from the multi-centre UK Small Aneurysm Trial. These have defined factors that influence outcome, time relations between expansion and risk of rupture for AAAs, and risk of death from other causes.
Maximum AAA diameter has long been considered the best predictor for outcome. However, small aneurysms can rupture with lethal results. A study for patients with ruptured AAAs measured diameter by ultrasound or computed tomography en route to theatre and found that 10% were 5.0cm or less in diameter (1). Another study showed that 5-year risks for rupture for small AAAs treated conservatively were 4% for patients with AAA < 4cm diameter and 21% for patients with AAA 4-5cm diameter (2). A further study found that the risk for rupture within 3 years for large AAAs in patients considered unfit for open surgery was 28% for AAAs 5.0-5.9cm diameter and 41% for AAAs > 6cm diameter, but that the larger proportion died from other causes (3).
The UK Small Aneurysm Trial commenced in 1991 and results have been reported since 1998 (4-9). The trial randomly assigned 1090 patients aged 60-76 years with asymptomatic AAAs 4.0-5.5 cm in diameter to undergo early elective open surgery or ultrasound surveillance. The 30-day operative mortality in the early-surgery group was 5.8%. Late mortality did not differ significantly between groups at 2-6 years. Health service costs were higher for surgery than surveillance.
The annual rupture rate was 2.2% and most occurred with AAAs 5-5.5 cm diameter. Risk was independently associated with female sex, larger initial AAA diameter, current smoking, lower FEV1, and higher mean blood pressure, but not with age, body mass index, serum cholesterol, or the ankle/brachial pressure index. Women were three times more likely to rupture than men. Risk was diminished if hypertension was well controlled or the patient stopped smoking. It was concluded that ultrasound surveillance is safe for small abdominal aortic aneurysms, that early surgery does not provide a long-term advantage, and that patients should have regular ultrasound surveillance followed by surgery for AAAs that grow by more than 1 cm per year or that reach 5.5 cm diameter.
An independent statistical analysis of the trial from the United States considered that early surgery could be cost-effective for younger patients with larger AAAs, but that decision-making should be guided by patient preference since gains in life expectancy would be small (10).
Local features within an AAA identify increased risk for rupture. Saccular AAAs have a more ominous natural history than typical fusiform aneurysms (11). Weakened areas within the wall increase the risk and these can be detected by CT scans (12). Spiral CT can show pathological dissection into the mural thrombus that predicts rupture (13). Direct pressure measurements near the aneurysm wall during open surgery show that thrombus within an aneurysm does not reduce the pressure near the wall so that it does not protect an AAA from rupture (14). Studies of AAA models show that pulsatile vortex flow and turbulence are responsible for expansion and eventual rupture (15). Operation and post-mortem studies find that most ruptures occur in the middle third where the aneurysm diameter is greatest (16).
Systemic factors also have an effect.
There is a stronger relation to smoking, male gender, diastolic hypertension
and family history for AAA than for atherosclerotic occlusive arterial disease,
with no significant relation to serum lipid levels and an inverse relation to
diabetes (17). Concomitant lower limb occlusive arterial disease does not adversely
affect long-term survival for patients who undergo open surgical repair for
2. DETECTING AAAs
The most common way to diagnose an AAA is by opportunistic detection without prior clinical suspicion during routine clinical examination, investigation for other diseases or laparotomy. However, opportunistic detection is not as effective as a formal screening program (1). Physical examination can miss more than one-third of AAAs detected radiologically (2).
Much has been learned from community ultrasound screening programs for AAAs, particularly in Europe and Western Australia. Attendance rates for those invited are 70-80% (3-5). A study of 13,000 men aged 60-75 years in Birmingham (UK) found the prevalence to be 6.9% for AAAs > 29mm diameter, and 1.8% for those > 40mm diameter (6). Screening is worthwhile if it reduces the risk of rupture. A study from the UK found that rupture was twice as likely in subjects invited to participate in screening compared to those not invited (7). Ultrasound screening for AAAs for more than 11,000 subjects in the UK and Netherlands showed that the risk of rupture over 5 years was < 20% for AAAs with initial diameter 4.5cm, and < 4% for AAA with initial diameter 3.0cm. (8, 9). However, there are conflicting views on whether surveillance is cost-effective and it would require a prospective trial comparing screened and non-screened populations to resolve this question (10).
Resources for surveillance are limited so that it should he more effective to target high-risk groups, such as relatives of patients with AAA, patients with symptomatic occlusive peripheral or cerebral artery disease, and patients with hypertension or those who smoke (11,12). These can be selected by a simple medical questionnaire (13). Even this is justified only if they are good candidates for surgery. In a British study, both the prevalence of existing and incidence of new AAAs rose steadily by age to reach a peak at age 65 after which both fell (14). However, an Australian study found that the prevalence increased from 4.8% in men aged 65-69 years to 10.8% for men aged 80-83 years (5). The prevalence for AAA was 11.9% in those with isolated systolic hypertension and 6.5% for normotensives (15). A recent study showed that current smokers were 7.6 times more likely and ex-smokers 3.0 times more likely to have an AAA than non-smokers (16). Each year of smoking increased the risk of AAA by 4%, and there was a slow decline in the incidence after stopping smoking. Serum cotinine levels were higher in men with a small aneurysm than in those with a large aneurysm suggesting that smoking is an initiating event, and cotinine levels were similar for stable and expanding aneurysms. The Australian study of over 12000 men found a significantly increased prevalence for Mediterranean-born compared to Australian-born men, for smokers, and for patients with associated peripheral or coronary artery disease, and a significantly lower prevalence for those who exercised regularly (5).
Screening might lead to unnecessary harmful psychological effects. However, a study that used a standard questionnaire for anxiety or depression found no significant difference between subjects screened and found not to have AAA, patients with known small aneurysms attending for follow-up scans, those with known AAA on waiting lists for surgery, or controls (17).
3. THE RATE OF AAA EXPANSION
An important finding from screening programs has been the rate at which AAAs enlarge, and this determines how often ultrasonography should he repeated. In the Birmingham report, one-quarter of AAAs did not enlarge at all over a mean 32 month follow-up, one-half enlarged by less than 2.5mm per year and the remaining one-quarter by 2.5-5mm per year, while sudden rapid enlargement was not observed (1). In another study, the mean expansion was 2.2mm/year in non-smokers and 3.0mm/year in smokers (2).
If the first ultrasound screen is negative for AAA, then it is necessary to ask whether it should be limited to once in a lifetime or repeated at intervals. The Birmingham study recommended that it was sufficient to perform ultrasonography at two-yearly intervals for AAAs < 40mm diameter, and at yearly intervals for larger AAAs (1). A study of more than 5000 men aged 50-79 years in the USA assessed the rate at which new AAAs develop (3). Of those with infrarenal aortic diameter <3.0cm on the initial ultrasound, follow-up at 4 years showed that only 2.2% had developed a new AAA and only 5% of these were > 4.0cm diameter. It was concluded that repeat screening at 4 years was of little value but that screening after 8 years would provide yields similar to those for the initial screening.
True growth can be diagnosed only if the measured increase in AAA diameter exceeds inherent variability for accuracy for the ultrasound scanning measurement. The Birmingham study noted that interobserver variability for ultrasound was similar to the upper limits for annual expansion (1). A Dutch study showed that the mean difference between two observers for ultrasound was 0.32mm for the proximal aorta, but that maximum differences between observers were 4.0mm (4). Interobserver variability increased with increasing waist circumference and increasing AAA diameter. A Canadian study showed that there was good interobserver agreement, but that only changes in measured diameter > 8mm indicate AAA growth at the 95% confidence level (5). Accuracy is greater for small aortas than for larger AAAs (6).
Studies in males for expansion rates
for iliac artery aneurysms (IAAs) show that IAAs expand at a considerably slower
rate than AAAs (7). The only patients to develop symptoms all had IAAs >
4 cm diameter. Mean expansion rates were 11mm/year for IAAs < 3cm diameter,
and 26mm/year for IAAs 3-5cm diameter. The study concluded that IAAs < 3.5
cm diameter should be followed with 6-monthly ultrasound, and that surgery should
be considered for asymptomatic IAAs > 3.5cm in good-risk patients, and for
IAAs > 4 cm in all patients. Co-existent femoral or popliteal aneurysms are
present in approximately 15% of males though rarely in females (8).
4. THE EVOLUTION OF TREATMENT FOR AAA
Most surgeons consider that surgical repair in fit patients is justified for AAAs > 50-55mm diameter (1) as shown in (2). The higher the operative risk, the larger the AAA needs to be before intervention should be considered (3).
Figure 1. The approximate risk of rupture of an AAA according to maximum transverse diameter (2).
For the past 50 years, standard surgery for AAA has been by open replacement with a Dacron graft, as introduced by Dubost in 1952 (4). This has proven to be durable but the operation is substantial with a potential for significant blood loss, serious metabolic changes, cardiac, respiratory and renal stress, and a more prolonged stay in the intensive care and general wards. A recent American study for open repair showed that the median stay in the intensive care unit was 2 days, and median in-hospital stay was 9 days with in-hospital mean cost of approximately US$26,000 (5).
The alternative now is endoluminal grafting (ELG) introduced by Parodi, Palmaz and Barone (6). ELG with straight, uni-iliac or bifurcated stent-grafts passed up through the femoral arteries and deployed under radiological control is effective. Non-randomized studies show that ELG for AAA is feasible in one-half to two-thirds of patients, with a low mortality and acceptable success rate during the short to intermediate term (7-15). Most surgeons find there is a steep learning curve for the first 50 patients or so (16). However, May and colleagues from Sydney found a similar incidence of adverse events in patients treated early or later in their experience suggesting that there are inherent risks for ELG rather than iatrogenic complications from the learning curve (17). There is far less blood loss, surgical stress and length of hospital stay after ELG than after open repair, although duration of surgery is about the same (18).
However, the respective merits for the two operations remain uncertain. One study calculated quality-adjusted life expectancy rates after open repair and ELG and found no benefit for ELG for men in average health with gradually enlarging AAAs and only minimal benefit for older men in poor health (19). Skeptics contend that although stent-grafts appear to be generally safe, their long-term efficacy is unknown, endovascular AAA repair has neither fewer complications nor lower mortality rates than open repair, and there are new complications particularly "endoleak" and device failure (20). Although it is uncommon, delayed AAA rupture after seemingly successful endovascular repair for AAA has been reported. They warn that these unique faults for ELG require a cautious approach to its clinical application.
Some follow-up studies report considerable anatomical changes in the aneurysms that place severe strains on the stent-grafts (21-23). The Sydney group point out that the ability of ELG to cause AAA shrinkage has the paradoxical risk of distorting the supporting metallic framework to predispose to late failures (24). It appears that reoperation is much more likely after ELG than for open repair (9,25) and this must be included in any analysis of long-term results.
Every vascular team that enters this field should audit their results. Responsible surgeons in several countries have taken auditing a step further by developing voluntary multi-centre registries. An outstanding example is EUROSTAR (European Collaborators on Stent-graft Techniques for Abdominal Aortic Aneurysm Repair) led by Harris and Buth who have collected more than 1500 patients (26-30). Their follow-up has identified that as many as two-thirds of patients develop appreciable anatomical changes in AAAs that predispose to structural breakdown of the prostheses and this has led to major manufacturing modifications. Another important registry is RETA (Registry of Endovascular Treatment of Aneurysms) led by surgeons and radiologists for the Vascular Surgical Society of Great Britain and Ireland which includes over 600 patients from 31 centers (31,32).
Harris and Buth (33) responded to criticism from Rutherford (34) that EUROSTAR had failed to promptly warn surgeons of structural defects in a commercial prosthesis, although manufacturers have been highly responsible in communicating device problems. Noncommercial regulatory bodies have not rushed forward to support the considerable costs of such audits, nor are all surgeons prepared to engage in the onerous task of completing audit forms. A result is that regulatory bodies in some countries are threatening to introduce compulsory auditing to receive payment for treatment.
These major exercises to seek information will unearth many problems with surgical technique and graft design but cannot answer the hypothesis that ELG is as effective as open repair in reducing the risk of death from AAAs (35). Audit alone will not validate the operation. Massive numbers will be required to develop matched patients in the many subgroups that can be defined. By the time such information is collected, major changes in surgical techniques and prosthesis design will make the early results obsolete.
Retrospective studies of ELG compared to historical controls for open surgical repair cannot prove the hypothesis that ELG is as effective as open repair for preventing death either from rupture of the AAA or from the treatment. The potential benefit is diminished trauma to the patient (36), although this becomes irrelevant if the new operation does not work sufficiently well. The potential cost is added expense to already depleted health resources which will likely be accepted if the new operation is effective.
Independent advisors argue that proving the hypothesis requires level I evidence with statistical evaluation from rigorous prospective randomized trials. A prospective randomized trial for ELG versus open repair has commenced in the United Kingdom, led by vascular surgeons who are well aware of the potential pitfalls (RM Greenhalgh, oral communication, December 1999). Their patient net is wide, all vascular surgeons who wish to participate are welcome, and realistic guidelines for patient selection have been based on current accepted indications for open repair. However, many patients will need to be recruited and followed over several years before statistical analysis is able to answer the null hypothesis that ELG is at least as good as open repair. Many vascular surgeons argue that by the time results are known, the new procedure will have changed to such a degree that the early operations in the trial will be archaic and irrelevant. Prospective randomized trials may be far more appropriate for long-established operations such as carotid endarterectomy than for evolving techniques. There has been a tendency for such trials to be restricted to a small group of elite surgeons treating a select fraction of the patient population to provide artificial results that do not apply to the "real world."
5. TECHNIQUES FOR OPEN SURGICAL REPAIR FOR AAA
Techniques for open repair are now very standardized with most surgeons performing an inlay operation suturing a tube or bifurcated graft within the aneurysm sac. There are a few disputed aspects. One relates to the best surgical exposure, particularly by the transperitoneal or retroperitoneal approach. In one American study, there was no difference between the frequency of pulmonary complications or incisional hernias, but significant reduction in cardiac and gastrointestinal complications, longer operative time and blood loss, less requirement for intravenous narcotics or epidural analgesia, and shorter hospital length of stay and hospital charges for the retroperitoneal approach (1).
Another American study found that there was no significant differences in mortality rates, and that retroperitoneal repair was associated with less frequent respiratory failure but more frequent wound complications, and lower hospital costs (2).
Another factor to consider is the presence of an infrarenal neck allowing clamping below the renal arteries. There have been studies of repair for AAAs involving the suprarenal, visceral, and lower thoracic aortic segments. These juxtrarenal, pararenal or suprarenal aneurysms present a particular challenge. They require suprarenal clamping with the risk of ischemic renal damage and they may require re-implantation or bypass grafting to renal or visceral arteries. An American study showed a 30-day mortality rate of 7% for elective repair and a survival rate of 71% at 3 years and 50% at 5 years (3). An Italian study found similar results with a 7% mortality rate for elective cases, and showed that age > 70 years, and coronary artery disease were the only independent predictors of early mortality (4).
The outcome for AAAs that have ruptured remains poor. A Swiss study found that a haemoglobin < 90g/l, systolic blood pressure < 80 mmHg and ECG signs of ischemia at admission were highly significant risk factors for a fatal outcome and that most deaths were due to multi-organ failure (5). An Italian study recorded a mortality rate of 24% with death due to irreversible haemorrhagic shock, intestinal infarction, acute renal failure, myocardial infarction, respiratory insufficiency or multiorgan failure (6).
6. TECHNIQUES FOR ENDOLUMINAL GRAFTING FOR AAA
Stent-grafts are of two types (1). The first is based on the concept that they should mimic standard surgical grafts with a unibody system as a tube or with two limbs. The second uses stent-grafts constructed within the AAA from modular components. Most surgeons now favour a prosthesis that is self-expanding with good radial force and longitudinal rigidity. This is most often placed as a bifurcation graft. The optimal design for the metal stent framework and its relation to the graft fabric is not known. It will be several years before it is clear as to how much metal corrosion or fatigue with late fracture occurs although this is already being seen in the early grafts. Nor is it known whether the relatively thin graft material used for the stents is strong enough to withstand deformation from prolonged beating with the pulse. Many grafts used have a metal framework of nitinol and we have reviewed the characteristics of this material (2).
The first generation stent-grafts included Parodi's original graft (3), many home made devices and the pioneering Mintec Stentor graft introduced by Miahle (4). Several companies have developed second generation grafts listed in and their websites provide varying information about the individual stent-grafts. May and colleagues from Sydney have compared results for early and more recent stent-grafts and have shown better patient survival and probability of graft success with second-generation prostheses (5). Third generation improvements are eagerly awaited as there are still many design faults recognised with growing experience. The challenge is to progressively improve both their design and surgical techniques to cope with the many difficult anatomical deviations that occur from patient to patient. Preliminary results have been identified for the Vanguard (6-9), Talent (10-14), EVT/Ancure (14-17), AneuRx (18-20), Zenith (21) and Endologix (22) grafts.
Table 1. Some commercial endoluminal grafts and their manufacturers.
The following discussion will describe some of the manoeuvres that we have used to allow ELG in these patients in the past and present practice with third generation stent-grafts (23). Our early experience was with the MinTec Stentor graft (29 patients), Boston Scientific Vanguard graft (22 patients), World Medical Talent graft (23 patients), and then with the Medtronic AneuRx graft (36 patients), but our preference now is to exclusively use the Cook Zenith graft (77 patients).
There were 18 straight grafts, 9 aorto-uni-iliac grafts with a femoro-femoral bypass, and 5 extension grafts, a modular bifurcated graft being used in the remaining 155 patients.
Acces for the sheaths for Stent-Grafts
An attempt has been made to insert all grafts through the common femoral arteries. Occasionally, it was predicted that the device would not pass up the external iliac artery because it was too small or tortuous, and it was then necessary to anastomose a short length of a wide-diameter Dacron graft to the common iliac artery through an extraperitoneal exposure to allow access. At the end of the procedures, the graft can be brought down as an iliofemoral bypass. It is current practice to expose both common femoral arteries to place a bifurcation graft but others are starting to achieve a bilateral percutaneous approach for both sides with preliminary placement of percutaneous closure devices. A long outer sheath directed over a super-stiff Lunderqvist (Cook) guide wire is now used to facilitate exchange for the graft. Several techniques were used in the past to gain access through a graft sutured to the artery or by arteriotomy, but current grafts are now introduced by arterial puncture ().
Figure 2. Techniques for femoral access for the sheath. 1-through a transverse arteriotomy, 2-through a dacron graft sutured to the arteriotomy, 3-through a strong outer sheath, 4-by puncture with a dilating tip to the sheath. Current devices should use the last method in all patients.
It is necessary to place a wire into the open limb of the main stem to lock in the contralateral limb. This can usually be quickly achieved by passing the wire up with a guiding catheter from the contralateral side. Occasionally, it was necessary to either pass the wire over the bifurcation from the ipsilateral side into the sheath or to thread the wire down from the arm. The various companies manufacture the main stem in different lengths. The longer the main stem, the easier it is to pass the wire if the iliac arteries are straight but the more difficult it can be if the iliac arteries are angulated ().
Figure 3. Manufacture of the main stem to improve access for the wire to the opening for the contralateral limb. 1-A long trunk improves access if the iliac arteries are straight. 2-A long stem makes access more difficult if the iliac arteries are angulated.
Tracking through the iliac arteries
Early devices were prone to cause trauma to the femoral and external iliac arteries, particularly from repeated exchange of the device. Both access and tracking was sometimes difficult or impossible if the external iliac arteries were too small or tortuous and this lead to danger of external iliac artery rupture or occlusion. The challenge to all companies has been to provide a sheath that is sufficiently narrow to allow easy passage thorough the iliac system yet strong enough to prevent kinking at points of angulation and flexible enough to track around curves. Newer sheaths with a long tapered tip to the dilator allow progressive dilatation and straightening making passage relatively safe and easy. Iliac tortuosity is not a contraindication to endoluminal grafting, for most iliac arteries can be straightened out, but the patient should be rejected if the tortuous artery is also heavily calcified indicating inability to straighten.
There are several techniques to improve access (). The super-stiff guide wire by itself will partly straighten out a tortuous iliac artery. In difficult cases in the past, the iliac artery was further straightened by pulling on a wire passed from a left brachial sheath through the length of the descending aorta and iliac artery and out through the femoral sheath, but this is now rarely required.
Figure 4. Techniques for improved iliac access. 1-A tortuous iliac increases the risk of perforation or failure to pass the sheath. 2-Access is improved if the artery is straightened by the guide wire, an outer sheath or a dilator.
Achieving a proximal seal
Several grafts have bare wire extending beyond the upper extent of the synthetic cover and it is now known that this bare wire can be placed across renal arteries without restricting renal blood flow. Accordingly, it is possible to place the Dacron right up to the renal arteries so as to require a very short length of neck. In practice, at least 1cm of neck is required between the lowest renal artery and the aneurysm for current grafts.
If there is angulation of the neck, then there is a risk that the graft will be poorly applied to the aortic wall on the convex side of the curve resulting in an endoleak (). However, proximal angulation should not be a contraindication to endoluminal grafting. A marker board with a rotation screw to vary the marker position placed behind the patient helps to ensure that the graft is deployed immediately below the renal arteries. The screen is coned down to show the precise centre and the marker is placed in this position so as to avoid any parallax error. A straight multi-sidehole catheter is passed from the contralateral side to show the renal arteries by angiography. The image intensifier is moved until angiography shows that the renal arteries are in the centre of the screen at the level of the marker. Angiography is repeated immediately prior to deployment to ensure that the graft is at exactly the correct level. If a preoperative lateral DSA has shown that there is anterior angulation then this manoeuvre is performed with the image intensifier tilted at an appropriate angle so as to avoid positioning the graft too low ( ). The ideal system provides extensions that can be placed at the time of operation if deployment is inadvertently too low so as to ensure that the upper end is well seated in the neck immediately distal to the renal arteries.
|Figure 5. Techniques to improve graft apposition to the aortic neck. 1-An unsupported graft is likely to lose contact on the convex side. 2-Wire extensions above the renal arteries stabilize the upper end.|
Figure 6. deployment of the graft immediately below the renal arteries is improved by tilting the tube to be transverse to the aortic neck.
Achieving a distal seal
The length of the main limb is calculated before operation to extend down to a segment of iliac artery that allows a distal seal, preferably above the internal iliac artery, at least on one side. It may be necessary to deliberately extend to below an internal iliac artery but this can cause severe buttock claudication. An aorto-uni-iliac graft can be placed with a femoro-iliac crossover graft to preserve the contralateral internal iliac artery, but this technique is rarely required now.
Extension of a common iliac aneurysm to the internal iliac artery on one or even both sides is not a contraindication to ELG. If the internal iliac is to be covered, then it is necessary to occlude it by coil embolization to prevent reflux into the AAA. Newer grafts are flared at the distal ends to seal wide common iliac arteries above the internal iliacs.
New techniques to allow for a short or absent proximal
Techniques are evolving that allow the graft to be placed well above the renal and visceral arteries if required, to achieve a firm seal to avoid an endoleak. Two groups from Australia have developed grafts with fenestration at the upper end at sites of renal or visceral arteries to allow stent-grafts to be placed above these vessels to secure an aortic seal if there is a very short neck (24-26). Fenestrations were cut into custom-made or commercially manufactured Zenith stent-grafts to preserve side-branch perfusion and guiding catheters were used to place Palmaz stents to overlap each fenestration and vessel orifice to secure the junction ().
Figure 7. A technique using fenestration of a
graft to extend the upper limit for sealing an AAA.
Recently, branched stent-grafts have been developed in Japan and the USA for AAAs that extend above the renal and visceral arteries, greatly extending the potential scope for the technique (27,28). Inoue and colleagues have developed multiple-branched stent grafts that can be delivered through a 22-24F sheath (27). Chuter and colleagues have described clinical application of a stent-graft system that preserves side branch perfusion (28). A modular endograft system includes three components that are delivered sequentially through surgically exposed femoral and right brachial arteries. The primary stent-graft is custom-made from conventional graft fabric and Gianturco Z-stents and the distal extensions are made from modified Zenith grafts ().
Figure 8. A technique using graft extensions
to place an ELG above renal and visceral arteries.
7. PREPPERATIVE MEASUREMENT OF AAAs FOR ELG
We favour the following protocol to measure an AAA to assess whether it is suitable for ELG and to order a graft with suitable proportions if it is decided to proceed. Duplex ultrasound scanning will frequently have been performed to detect the AAA and a high-quality ultrasound scan is also arranged to measure the diameter of the iliac arteries and detect any stenotic or occlusive disease. A standard contrast-enhanced computed tomographic scan (CTA) with very fine slices at each end (2-3mm) is performed. Electronic calipers measure the dimensions of the neck (suprarenal diameter, length of the neck, diameter of the infrarenal neck just below the lowest renal artery and just above the AAA), diameter of the AAA, and diameters of the common iliac arteries. The CT scan also displays whether there is thrombus, calcification or atheroma in the neck. Three-dimensional reconstruction is very useful to measure angulation in the lateral and anteroposterior planes of the neck at the junction of the suprarenal and infrarenal segments and junction of the infrarenal segment with the AAA, as well as tortuosity of the iliac arteries.
If the CTA shows that the anatomy is suitable, then digital subtraction angiography (DSA) is arranged with a marker pigtail catheter. After a preliminary run to determine the level of the visceral arteries, the infusion holes of the catheter are drawn down to be level with the renal arteries to give best definition of the neck. Films of the neck and AAA are obtained in the anteroposterior projection and with 200 oblique projections to best show each renal artery and a lateral projection to show the visceral arteries. The marker catheter is then used to show the length of the neck and length from the lowest renal artery to AAA bifurcation. The catheter is drawn down to cover the low AAA and iliac arteries and anteroposterior and 300 obliques are used for further runs. The length from the AAA bifurcation to the ipsilateral internal iliac artery is measured and an extrapolation is made for the length of the contralateral common iliac artery. Calculations are made for each diameter as for the CT scan as well as for iliac artery diameters. Angles at the neck and angles and tortuosity for each iliac artery system are determined. If renal function permits, further films are obtained to demonstrate each femoropopliteal runoff segment.
Beebe and colleagues have promoted spiral CTA with 3-dimensional reconstruction without preoperative DSA to evaluate the aortoiliac segment for ELG (1). A French study considered that helical CTA is highly accurate for measurements of AAAs (2). Hopkinson and colleagues from Nottingham found a good agreement between CTA and DSA for measuring aortoiliac length, with 69% of aortic and 76% of iliac measurements within 1 cm and > 90% within 2 cm of each other (3). However, DSA overestimated renal artery to aortic bifurcation length in patients with large-diameter aneurysms and wide aneurysm lumens. They consider that CTA is sufficiently accurate in most cases to be used as the sole basis for constructing ELGs. A Swedish study found that AAA neck diameter was consistently smaller on DSA than on CTA (mean 20.7mm versus 23.0mm), and that the length from the most distal renal artery to the aortic bifurcation was greater from DSA than from CTA (mean difference 10.0 mm) (4). A Belgian study found that observer variability for CT measurements of the aorta and iliac arteries for patients with AAAs regularly exceeded 2mm in spite of using a workstation and electronic calipers (5). Additional functional information about renal perfusion can be obtained from the initial timing scan of a CT study (6). An American group found that DSA cost over 3 times more than CTA for preoperative imaging for AAA (7).
Gadolinium-enhanced magnetic resonance angiography (MRA) is accurate when compared to DSA or CTA (8). The Nottingham group consider that contrast-enhanced MRA can be effective as the sole imaging modality to assess patients prior to ELG (9). Gadolinium-enhanced MRI readily demonstrates features of inflammatory AAAs, and it may be preferable to CTA in view of potential renal impairment in these patients (10). Intravascular ultrasound provides accurate and reproducible measurements of AAAs (11).
8. SELECTION FOR TREATMENT
There is uncertainty as to the indications for operation for AAAs by any method. There is even less agreement as to the relative indications for open repair and ELG. In addition, laparoscopic repair for AAAs is being explored (1,2). Because ELG for AAAs is less invasive, some surgeons have suggested that this should broaden the indications for elective intervention. However, the prognosis for healthy patients who undergo elective AAA repair by open surgery is good (3). Mohan and Harris suggest that contraindications to open repair are few but include small aneurysms (< 5.5 cm), a co-morbidity that increases surgical risk by > 10% and a life expectancy of < one year (4). Much the same could be said about ELG.
Factors that influence the decision to consider ELG are AAA diameter, physician and patient preference, general health of the patient, and anatomical criteria that allow for ELG to be considered. The influence of AAA diameter and other aneurysm characteristics have been discussed.
Physician and patient preference
There are important unanswered philosophical questions. Should ELG be reserved for poor-risk patients who might not tolerate open surgery? Would liberal expansion of the indications to all suitable candidates bring about more effective and cheaper treatment? Is the best time to treat an AAA when it is small and thus simple and safe to control? ELG may be seen to be an easy option to arrest expansion long before an AAA poses a threat. This in turn would intensify a push for early detection by ultrasound screening. It remains to be seen whether this would be cost-effective.
General health of the patient
The most usual criteria for assessing fitness is the American Society for Anesthesiology (ASA) classification. The Nottingham group defined "high-risk patients" as having at least one of the following features - serum creatinine > 150 micromol/l, ischemic heart disease or poor left ventricular function, respiratory function < 50% of predicted normal, ruptured or symptomatic AAA, contraindication to or failed open repair, and age > 80 years (5). Health systems in some countries restrict ELG to poor-risk patients to restrain costs. Initially, we restricted ELG to poor-risk patients with aneurysms > 50mm diameter, but we now consider fit patients who prefer this procedure. Endovascular repair for ruptured AAAs is feasible (6).
Anatomical requirements for ELG
Not all aneurysms are suitable for ELG as the graft must be able to form a good seal against relatively normal artery at each end. Several anatomic constraints are common for each graft (7). Ideally, the AAA should commence well below the level of the renal arteries providing a long, straight and relatively narrow aortic neck to allow a good proximal seal. There should be minimal dilatation of the common iliac arteries, tapering down to a relatively small diameter to allow a good distal seal above the internal iliac arteries. Finally, there should be good access through a wide and relatively straight external iliac artery on each side. These may be found in patients with relatively small aneurysms, but it is uncommon to have all or indeed any of these favorable anatomical configurations for patients with larger aneurysms.
The first generation grafts had a rather narrow application due to anatomical constraints. American surgeons found that the first-generation EVT system was unsuitable for a tube graft in 90% and for a bifurcated device in 85% due to an unsuitable proximal neck in 48%, and unsuitable iliac arteries in 41% (8). Another American report for the early EVT graft found that many patients were rejected due to insufficient proximal neck (21%), proximal neck too large (17%), calcification, kink, or extensive thrombus in the proximal neck preventing safe graft attachment (5%), distal common iliac aneurysm or insufficient distal iliac neck (21%), iliac stenosis (28%), and patient preference (8%) (9).
Subsequent second generation grafts could be more widely applied. The Nottingham group found that commercially available devices could be used in about one-half of potential candidates (10). An American group also found that about one-half were potentially eligible for ELG with the AneuRx device, the most common cause for rejection being an inadequate proximal neck (11). Over 3 years, the eligibility rate increased from 45% during the first 18 months to 63% during the second 18 months. Potential candidates were younger, and their aneurysm diameter tended to be smaller. A study of the Ancure and Talent systems examined gender-related anatomic variables and found that 63% of women were rejected versus only 33% of men (12). Maximum AAA diameter and iliac artery tortuosity were similar in both but proximal neck length was shorter, proximal neck width was wider, proximal neck angulation was greater, and the external iliac artery was smaller in women than in men.
We studied 158 potential candidates for ELG with the earlier Vanguard and Talent grafts and the numbers suitable for ELG and the anatomical reasons for rejection are shown in . The numbers suitable for ELG would now be higher with the introduction of third generation grafts, and ELG may become suitable for all patients if recent developments for stent-grafts with branches that allow extension above and below critical arteries are shown to be effective.
|Table 2. Anatomical reasons for rejection of patients for ELG in 158 patients assessed in our unit for Vanguard or Talent stent-grafts.|
Table 3. Suitability according to the approach to place the sheath for 158 patients assessed in our unit for Vanguard or Talent ELGs.
|Table 4. Suitability according to the type of graft used for 158 patients assessed in our unit for Vanguard or Talent ELGs.|
ELG can be safely performed for patients with anomalous renal vessels when the main renal vascular anatomy can be preserved and when the loss of only small branches (< 3 mm) occurs in patients with otherwise normal renal function (13). ELG is the technique of choice for many patients with a horseshoe kidney (14). The inflammatory aneurysm is well suited to endoluminal repair (15).
9. COMPLICATIONS AND RESULTS AFTER OPEN SURGICAL REPAIR
The postoperative mortality rate for elective open repair in most series is approximately 5% (1), and although this is far lower in selected fit young patients, it can be disturbingly high in older poor-risk patients. A recent Dutch study found that in-hospital mortality after elective surgery for infrarenal AAA was 4.1%, more than half resulting from cardiac failure (2). They found that 26% experienced some systemic complication, the most frequent being cardiac and pulmonary (10% each). Another analysis for mortality after elective open repair showed that age, AAA diameter, postoperative myocardial infarction, operation time and volume of intraoperative blood loss, and respiratory complications or gastrointestinal bleeding were determining factors (3). A German study presented 10 year follow up for 521 patients operated on by elective open repair for AAA between 1978 and 1987 (4). The in-hospital mortality rate was 6.4%, and the cumulative survival rate was 65% at 5 years and 41% at 10 years, the mean survival time being 95 months. Age, coronary artery disease and hypertension were adverse factors for survival.
Inhibition of systemic fibrinolysis and intense thrombin generation contribute to microvascular and macrovascular thrombosis and these predispose to myocardial infarction, multiple organ failure, and thromboembolism and account for much of the morbidity and mortality for open repair (5). Thrombogenicity and platelet deposition may be most active in the aneurysm sac (6,7).
Open surgery for juxta- or pararenal aortic aneurysms provide particular technical problems and risk to the patient compared to those for infrarenal aneurysms. In one study there was a higher risk of early mortality (12% v 3.5%) and reduced long-term survival (40% at 5 years) (8). The reported mortality for ruptured abdominal aortic aneurysms (RAAA) remains very high varying from 15% to 50%, commonly due to irreversible haemorrhagic shock, intestinal infarction, acute renal failure, myocardial infarction, respiratory insufficiency or multiorgan failure (9).
Preoperative cardiac screening, for example with thallium scanning and/or coronary angiography, can reduce perioperative risk and improve long-term outcome. In a recent study, 33% of patients with no cardiac history and a normal ECG were found to have significant coronary artery disease and 20% required initial cardiac intervention followed by expedient aneurysm repair with zero mortality (10).
10. COMPLICATIONS AFTER ELG FOR AAA
These are classified in (1-3). The Nottingham group studied the risk of proximal type I endoleak or graft migration in relation to aortic neck morphology (4). Neck diameter and angulation were greater for both complications, but conical shape, thrombus, atheroma lining or calcification in the neck did not influence the risk for either. For the early EVT grafts, endoleaks were frequent (38%) but most closed spontaneously (5). In vitro studies with IVUS and CT show that the stent at the upper end follows aortic wall movement through the cardiac cycle to differing degrees, and that oversizing the stent in relation to neck diameter can lead to graft folding with a potential for poor apposition during systole predisposing to endoleaks (6).
Table 5. Definitions of endoleak and endotension (1-3)
Many endoleaks close spontaneously. Endovascular treatment for primary or secondary endoleaks is usually possible by placing graft extensions or bare stents, and this is usually safer than conversion to an open procedure (7). Coiling to produce a radiographic seal can be achieved in all persistent cases, but whether this method is effective in the long term remains to be seen (8).
The Nottingham group described a method to prevent lumbar artery type II endoleaks (9). An aneurysmogram performed prior to deploying the iliac occluder detects patent aortic side branches. If these are found, an absorbable gelatin sponge is inserted into the aneurysm sac via the sheath. No side branch endoleaks were detected over a median 4 month follow-up. Type II endoleaks shown to be due to retrograde flow in the inferior mesenteric artery by selective arteriography with a catheter in the superior mesenteric artery can be controlled by coil embolization after advancing the catheter through to the left colic artery (10). Similar techniques have been described to occlude the inferior mesenteric by advancing a catheter from the internal iliac to the left colic artery (11).
Aneurysm shrinkage causing graft distortion
Several studies have shown that AAAs shrink after complete endovascular exclusion. Measured changes in the aortic neck diameter, AAA diameter and aortic length show patterns that may affect the durability of endovascular repair and potential strategies for future graft design (12). The Stanford group measured maximum AAA diameter after ELG by CTA and found that the mean absolute decrease in diameter was > 3mm at 6 months and > 5.5mm at 12 months for patients without endoleaks (13). The Sydney group measured endograft length after implantation and found graft shortening > 15mm in approximately one-half using Vanguard or AneuRx ELGs (14). A Dutch study came to a different conclusion using the EVT graft, which is a vertically non-rigid prosthesis that should potentially accommodate longitudinal changes (15). At 6 months follow-up, there was a decrease in AAA volume in two-thirds of patients, but changes in length were within the measurement error range of 4 mm in most, and they concluded that aortic shortening is not a clinically significant problem. However, a German group reported surveillance after ELG by DSA and CTA in 291 patients and documented distortions considered to be mild (31%), significant (angulations reaching 60-900 - 22%), or severe (angulations > 90º - 3%) (16). They concluded that the durability of stent-grafts cannot be evaluated with less than 3 years follow-up.
Aneurysm dilatation anf graft migration
Long-term changes in the infrarenal neck diameter after open surgery show that the annual growth rate is approximately 0.5 mm, and this raises concern regarding long-term success after endovascular repair (17). For straight EVT grafts, neck diameters at both graft attachment sites measured by CT scans showed dilatation by 0.7-0.9mm/year for the proximal aortic neck and 1.7-1.9mm/yr for the distal end (18). Expansion rates did not relate to initial neck size, stent-graft dimensions, AAA size change, endoleak, or attachment system fracture. The Sydney group confirmed the poor mid-term outcome for tube prostheses due to distal aortic dilatation (19). A Dutch study for the EVT stent-graft found a median increase in proximal neck diameter by 10% at 6 months and 15% at 12 months (20). There was no correlation between the amount of dilatation and pre- or postoperative neck-size, graft diameter or amount of graft-oversizing. A Swedish study using CT found a mean 1.65mm increase in the infrarenal AAA neck diameter, but only 0.52mm increase in diameter at the level of the superior mesenteric artery after 2 years (21). There was no correlation between diameter change and preimplantation infrarenal neck diameter.
A study of distal migration after ELG showed migration (distal movement > 5 mm) in 45% during a mean 13 month follow-up due to proximal AAA neck dilatation or poor patient selection (22). These were treated by additional stent-grafts as proximal extensions or late conversion to open repair.
Conversion to open surgery
Conversion from endovascular to open repair may be required and reasons that have been reported are shown in (23-25). The EUROSTAR collaborators studied factors that increased the risk for conversion (23). Patients who were converted were significantly older, and had a lower body weight, and higher prevalence of chronic obstructive pulmonary disease. Conversion was more likely with shorter, wider infrarenal necks and larger aneurysms. Conversion was less likely for teams that had performed more than 30 procedures, and in procedures performed during the last two years of the study period. Patients who required primary conversion had an 18% mortality rate compared to 2.5% mortality for patients without conversion.
|Table 6. Some reported reasons for conversion from ELG to open repair (23-25).|
Haematological and biochemical changes
Barras studied patients in our unit for several parameters and showed that most biochemical and hematological parameters were far less disturbed by ELG compared to open repair. (26). A Norwegian group measured leukocytes, platelets, myeloperoxidase, lactoferrin, beta-thromboglobulin, C-reactive protein, interleukin-6, tumor necrosis factor alpha and complement activation products before, during and after ELG or open surgery (27). Leukocyte and platelet activation occurred with both, perhaps due to radiographic contrast media for ELG and declamping after open repair, while the other products showed little change. A Japanese study measured the white blood cell count, granulocyte elastase, interleukin-6 and -8, and serum C-reactive protein as markers for biological responses, and found that all were higher after ELG than after open repair, levels peaking on the third postoperative day (28). The Nottingham group found that plasma endotoxin, tumor necrosis factor alpha (TNF-alpha), and interleukin 6 (IL-6) levels were lower after ELG compared to open repair, and they provided some evidence to suggest that this may be due to sigmoid colon ischaemia (29). There are similar responses in circulating monocytes and HLA-DR expression on lymphocytes after endovascular and open repair of AAA , and there is pronounced downregulation of monocyte HLA-DR expression in patients with severe postoperative complications after either treatment (30).
For most devices, proximal stent-graft fixation is improved by placing an uncovered part of the proximal stent above one or both renal artery orifices, and experimental and clinical data suggest that this does not lead to impaired renal function (31). Femoral artery access complications, risk of distal femoral artery occlusion and immediate graft limb occlusion are all highly dependent on the graft used and are becoming far less common with new systems that do not require arteriotomy. Rectum and sigmoid colon necrosis with fatal outcome due to cholesterol embolization after implantation of a stent-graft for an infrarenal AAA has been reported (32).
Impaired renal function can be a problem with ELG. In one study, approximately 6% of patients with normal preoperative renal function developed renal dysfunction after ELG, independent of the median dose of intravascular contrast used (33). The perioperative mortality rate was 27% for patients with preoperative renal impairment. ELG under local anesthesia can be performed safely in patients with significant comorbidities, potential advantages including decreased cardiopulmonary morbidity, shorter stay in hospital, and lower hospital costs (34).
11. RESULTS AFTER ELG FOR AAA
Good initial results can be achieved with stent-grafts and the less invasive nature of the technique makes it most attractive. However, there are various perioperative and late complications.
May and colleagues from Australia probably have the largest reported single unit experience (1). For 243 patients with AAA who underwent primary ELG, grafts were successfully deployed in over 90% and the perioperative mortality rate was 3.3%. In a separate publication, they compared elective open repair in 195 patients and endoluminal repair in 108 patients with no significant difference for perioperative mortality or late survival (2). Success for ELG was defined as continuing graft function without endoleak or conversion to open repair and there was a 3-year graft success probability of 70%. The same group reported life-table analysis for 266 patients treated by ELG for AAA between May 1992 and December 1998 (3). Primary success was defined as exclusion of the aneurysm from the circulation from the original operation. Assisted success occurred when aneurysms with endoleaks became excluded from the circulation as a result of supplementary endovascular intervention.
Hopkinson and colleagues from Nottingham found from their extensive experience with ELG in over 200 patients that the overall perioperative mortality for ELG was 3.7% in "acceptable-risk patients" and 11.3% in "high-risk patients" (4,5).
The most common causes of perioperative death were multisystem organ failure and myocardial infarction. They encountered intraoperative technical problems in 40% including endoleaks, graft stenosis, failure of graft deployment, graft thromboses, aortoiliac ruptures, renal artery occlusions, and internal iliac occlusions, so that conversion to open repair was required in 19%
The early success rate and risk factors for adverse events were reported for the EUROSTAR audit of 1554 patients with AAAs treated between 1994 and 1999 (6). Thirty-day mortality was 2.6% and mortality was related to the ASA classification, year of operation and need for adjuvant procedures. There were systemic complications in the first 30 days in 18% and this was higher for age > 75 years, impaired cardiac status, and for patients considered unfit for an open procedure. Intraoperative complications were failure to complete the procedure (2.5% of which two-thirds underwent conversion to an open repair), device-related or procedure-related complications (10%), and arterial complications (3%). Important risk factors for failure to complete the procedure were AAA diameter > 60mm and a need for adjuvant procedures. Factors that predicted device-related and arterial complications were the team experience and need for adjuvant procedures. An endoleak was detected at completion in 16% and was still present after one month in 9%, and risk factors for primary endoleaks were female gender and age >75 years.
For the AneuRx graft, a prospective nonrandomized multicentre trial that compared ELG with open repair showed no significant difference in operative mortality rates between the groups (7). Patients treated by ELG had significantly less blood loss, time to extubation, and days in the intensive care unit and in hospital, with an earlier return to function.
Primary technical success at discharge for patients with ELG was 77%, largely due to a 21% endoleak rate that had decreased to 9% by one month. A European study for 104 patients treated with the AneuRx graft reported two conversions, a mean operating time of 148 min and mean blood loss of 605 ml, and few complications except for four endoleaks persisting at 12 months (8).
The more recent Ancure endografting system has now been used in over 870 patients to late 1999 (9). The device was deployed successfully in over 90%, mortality rates were similar to those for open surgery but serious morbidity was reduced. Long-term follow-up of the bifurcated group showed only one migration and no ruptures, and aneurysm size was reduced in over 50% at one year and 68% at two years. Type I endoleaks were noted in only 2.7% at 1 year and 1.3% at 2 years.
The most recent multi-centre review of the Zenith graft used in 528 patients with a 2-year follow-up found successful graft implantation in all but four, an overall endoleak rate of 15% of which 4% were treated urgently for attachment site faults, 8 endograft migrations with an early version of the system, three late conversions and two ruptures (10).
We have performed endoluminal repair for AAAs in 187 patients over a six-year period from December 1994 to March 2001. Throughout this time, our policy has been to consider a patient for intervention only if the aneurysm was 5cm or more in diameter. An exception was made in three patients with smaller saccular aneurysms, two atherosclerotic and one post-traumatic where it was considered that the risk of rupture was high. Initially, it was our policy to limit endoluminal grafting to patients with serious co-morbidity, most often from severe coronary artery disease, chronic obstructive airways disease or chronic renal failure. We now accept any patient for ELG who elects to prefer the procedure after full discussion of the known benefits, late complications and unknown outcome. Endoluminal grafting is also preferred to open surgery if there is a "hostile abdomen'. It is necessary to have an anatomical configuration suitable for endoluminal grafting. The initial results are shown in and the long-term life-table analysis for success (continuing patency without endoleak or occlusion) for first operations on an intention-to-treat basis in172 patients are shown in . There is a highly significant improvement in outcome for the first half of the patients treated compared to the more recent second group.
|Table 7. Perioperative complications in our unit with various commercial stent-grafts used for ELG for AAA.|
Figure 9. Life-table curves for 172 patients undergoing first operations by ELG in our unit. These are divided into the first and second half of our practice to show the marked improvement in outcome with more modern grafts and increasing experience.
12. SURVEILLANCE AFTER ELG FOR AAA
An American group has described an algorithm to diagnose persistent primary endoleaks (1). A spiral CT scan is performed in all patients prior to discharge. If the initial CT shows no endoleak, colour-flow duplex scanning is performed at 1 month, with repeat CT scans at 6 months and 1 year. If the initial CT reveals an endoleak, a repeat CT scan is performed at 2 weeks, 1 month, and 3 months, or until the endoleak resolves. If an endoleak persists beyond 3 months, angiography is performed to localize the source.
A blinded study showed that the sensitivities and specificities for detecting a type I endoleak were 63% and 77% for conventional DSA and 92% and 90% for CTA, showing that the latter is more accurate (2). Another study compared the accuracy of ultrasound scanning compared to CT scans to diagnose endoleaks (3). Ultrasound showed satisfactory B-mode images in 93%, satisfactory colour-Doppler scan images in 76%, colour-Doppler scan assessment of the entire AAA sac in 55%, spectral Doppler scan waveform confirmation of suspected endoleaks in 27%, and all four criteria in 19%.
However, the sensitivity, specificity, positive and negative predictive values and accuracy for ultrasound compared to CT using any criteria were 97%, 74%, 66%, 98% and 82% respectively, and the excellent sensitivity and negative predictive value were considered to make ultrasound assessment reliable for surveillance. An Australian study concluded that CT did not provide any additional information than that obtained from the duplex scan for endoleaks (4). A French study found that duplex ultrasound scanning had a sensitivity of 96% and specificity of 94% when compared to CT but that it was a poor method for determining changes in AAA diameter (5).
13. COMPARISON OF COSTING FOR OPEN REPAIR AND ELG
Financial implications have been studied. It is calculated that the rise in the number of elderly people over the next two decades will increase the workload by over 40% for AAAs (1). At this time, tangible benefits for ELG are reduced costs for inpatient stay and less or no need for intensive care facilities during recovery. As yet, there is no less time spent in the operating theatre but this may come down as surgeons become more proficient and devices become more user-friendly.
Initially, many surgeons and radiologists wanted to be involved, but manpower requirements are already retreating to the conventional anaesthetist, surgeon and single assistant. There has been a far greater requirement for expensive investigations by imaging during preoperative evaluation and postoperative surveillance for ELG, but as techniques improve and confidence grows these will progressively decrease in number.
An early study by our group that concentrated on the impact that this new technology would have on financial support in a public hospital concluded that development of ELG is economically incompatible with current funding methods (2). This work was continued by Barras who showed that there were savings for ELG for both direct and indirect hospital costs but that the average cost of prostheses for ELG was more than 10 times that for open repair, amounting to well over 50% of the average overall cost (3). The results for in-hospital expenses are summarized in . A further Australian study took the process a step further (4). They showed that combined costs for primary in-hospital treatment, readmissions and lifelong follow up were more than 50% higher for ELG than that for open repair. There was less time spent in hospital and intensive care so that hospital costs were some 50% lower for ELG, and this was only partly offset by higher preoperative and postoperative costs for imaging and surveillance for ELG. The reason for the overall discrepancy was the cost of the stent-graft which amounted to some 50% of the total immediate expense for ELG.
Figure 10. Histograms showing relative costs for open repair and ELG for 10 patients in our unit.
Several American studies have analyzed where cost savings could be effected. Quinones-Baldrich and colleagues (5,6) concluded that endovascular grafting is "unlikely to save money for the health care system (and) its use is likely to be driven by patient and physician preference in view of a significant decrease in the morbidity rate and length of hospital stay." Another study showed that total inpatient hospital costs for ELG were significantly higher than for open repair (mean $19,985 versus $12,546), and that stent-graft cost ($10,400) accounted for 52% of the total cost for ELG (7).
They anticipated that reductions in cost for ELG may result if use of diagnostic studies, operating time, and length of stay decrease, but that device cost has the single greatest impact on the expense, and that Medicare reimbursement does not cover the cost. Another analysis agreed that operating room time, length of stay, costs for the hospital stay, laboratory, pharmacy, nursing, and anesthesia requirements were all higher for open repair than for ELG, but that despite these marked differences, the total cost was much higher for ELG due to the expense of the stent-grafts (8). A further study found that ELG is a cost-effective alternative on the basis of average costs for immediate hospitalization ($16,016 for open repair, $20,083 for ELG), complications from each procedure, and subsequent interventions, provided that ELG produced a large reduction in combined morbidity and mortality (9).
The expense for a prosthesis does not rest in the wire, fabric and plastic accessories of the device itself. Recompense is due to companies for the intellectual effort, prolonged research, inevitable setbacks, and risk taken by the manufacturers. Many presumably also realize that their days in the field are few and that profits must be taken quickly. Nevertheless, the trade in general is at risk of outpricing itself. As the number of operations performed increases, exponentially it seems, the burden will undoubtedly result in protest from those who supply the money.
1. The Natural History and Risk of Rupture for AAAs.
1. Nicholls SC, Gardner JB, Meissner MH, H Johansen K. Division of Vascular Surgery, Department of Surgery, Harborview Medical Center, University of Washington School of Medicine, Seattle, USA. Rupture in small abdominal aortic aneurysms. J Vasc Surg 1998 Nov;28(5):884-8
2. Galland RB, Whiteley MS, Magee TR. Department of Surgery, Royal Berkshire Hospital, Reading, U.K. The fate of patients undergoing surveillance of small abdominal aortic aneurysms. Eur J Vasc Endovasc Surg 1998 Aug;16(2):104-9
3. Jones A, Cahill D, Gardham R. Chase Farm Hospitals NHS Trust, The Ridgeway, Enfield, UK. Outcome in patients with a large abdominal aortic aneurysm considered unfit for surgery. Br J Surg 1998 Oct;85(10):1382-4
4. The UK Small Aneurysm Trial Participants. Mortality results for randomised controlled trial of early elective surgery or ultrasonographic surveillance for small abdominal aortic aneurysms. Lancet 1998 Nov 21;352(9141):1649-55
5. UK Small Aneurysm Trial Participants. Health service costs and quality of life for early elective surgery or ultrasonographic surveillance for small abdominal aortic aneurysms. Lancet 1998 Nov 21;352(9141):1656-6
6. Greenhalgh RM, Forbes JF, Fowkes FG, Powel JT, Ruckley CV, Brady AR, Brown LC, Thompson SG. Early elective open surgical repair of small abdominal aortic aneurysms is not recommended: results of the UK Small Aneurysm Trial. Steering Committee. Eur J Vasc Endovasc Surg 1998 Dec;16(6):462-4
7. Brown LC, Powell JT. Department of Vascular Surgery, Imperial College at Charing Cross, London, United Kingdom. Risk factors for aneurysm rupture in patients kept under ultrasound surveillance. UK Small Aneurysm Trial Participants. Ann Surg 1999 Sep;230(3):289-96; discussion 296-7
8. Ballard DJ, Fowkes FG, Powell JT. Center for Clinical Evaluation Sciences, Emory University School of Medicine, Decatur Plaza, Suite 620, 101 W. Ponce de Leon Avenue, Decatur, GA 30030, USA. firstname.lastname@example.org Surgery for small asymptomatic abdominal aortic aneurysms. Cochrane Database Syst Rev 2000;(2):CD001835
9. The UK Small Aneurysm Trial Participants. Smoking, lung function and the prognosis of abdominal aortic aneurysm. Eur J Vasc Endovasc Surg 2000 Jun;19(6):636-42
10. Schermerhorn ML, Birkmeyer JD, Gould DA, Cronenwett JL. Department of Surgery, Dartmouth-Hitchcock Medical Center, Lebanan, NH 03756, USA. Cost-effectiveness of surgery for small abdominal aortic aneurysms on the basis of data from the United Kingdom small aneurysm trial. J Vasc Surg 2000 Feb;31(2):217-26
11. Taylor BV, Kalman PG. The Toronto Hospital Vascular Center, Department of Surgery, University of Toronto, Toronto, Ontario, Canada. Saccular aortic aneurysms. Ann Vasc Surg 1999 Nov;13(6):613-7
12. Scorza R, De Monti M, Lazaridis J, Sgroi G, Ghilardi G. Chair of General Surgery, Institute of General and Cardiovascular Surgery, University of Milan, Italy. Wall lesions of abdominal aortic aneurysms threatening an impending rupture: prognostic evaluations. Int Angiol 2000 Mar;19(1):59-63
13. Arita T, Matsunaga N, Mita T, Furukawa M, Hara A, Sasai K, Ikenaga S, Takenaka H, Zempo N, Esato K. Department of Radiology, Yamaguchi University School of Medicine, Ube, Japan. Spared flow tract within the mural thrombus of an aortic aneurysm: its pathogenesis and clinical importance. J Comput Assist Tomogr 2000 Jan-Feb;24(1):86-91
14. Schurink GW, van Baalen JM, Visser MJ, van Bockel JH. Department of Surgery, Section Vascular Surgery, Leiden University Medical Center, Leiden, The Netherlands. Thrombus within an aortic aneurysm does not reduce pressure on the aneurysmal wall. J Vasc Surg 2000 Mar;31(3):501-6
15. Egelhoff CJ, Budwig RS, Elger DF, Khraishi TA, Johansen KH. Mechanical Engineering Department, University of Idaho, Moscow, USA. email@example.com Model studies of the flow in abdominal aortic aneurysms during resting and exercise conditions. J Biomech 1999 Dec;32(12):1319-29
16. Golledge J, Abrokwah J, Shenoy KN, Armour RH. Department of Surgery, The Lister Hospital, Corey's Mill Lane, Stevenage, SG1 4AB, U.K. Morphology of ruptured abdominal aortic aneurysms. Eur J Vasc Endovasc Surg 1999 Aug;18(2):96-104
17. Blanchard JF, Armenian HK, Friesen PP. Epidemiology Unit, Public Health Branch, Manitoba Health, Winnipeg, Canada. Risk factors for abdominal aortic aneurysm: results of a case-control study. A m J Epidemiol 2000 Mar 15;151(6):575-83
18. Hassen-Khodja R, Le Bas P, Pittaluga P, Batt M, Declemy S, Bariseel H. Department of Vascular Surgery, Centre Hospitalier Universitaire de Nice, Hopital Saint-Roch, France. Abdominal aortic aneurysm and lower-limb occlusive arterial disease. J Cardiovasc Surg (Torino) 1998 Apr;39(2):141-5
2. Detecting AAAs
1. Tisi PV, McLain AD, Jeddy TA, Ashton HA, Scott RA. Department of Vascular Surgery, St. Richard's Hospital, Chichester, West Sussex, U.K. Screening for abdominal aortic aneurysm: is opportunistic detection a realistic alternative? Eur J Vasc Endovasc Surg 1998 Jun;15(6):532-4
2. Karkos CD, Mukhopadhyay U, Papakostas I, Ghosh J, Thomson GJ, Hughes R. Department of Surgery, Royal Preston Hospital, Preston, England, UK. Abdominal aortic aneurysm: the role of clinical examination and opportunistic detection. Eur J Vasc Endovasc Surg 2000 Mar;19(3):299-303
3. Boll AP, Verbeek AL, van de Lisdonk EH, van der Vliet JA. Department of Surgery, St Radboud University Hospital, Nijmegen, The Netherlands. High prevalence of abdominal aortic aneurysm in a primary care screening programme. Br J Surg 1998 Aug;85(8):1090-4
4. Lindholt JS, Juul S, Henneber EW, Fasting H. Department of Vascular Surgery, Viborg Hospital, Denmark. Is screening or abdominal aortic aneurysm acceptable to the population? Selection and recruitment to hospital-based mass screening for abdominal aortic aneurysm. J Public Health Med 1998 Jun;20(2):211-7
5. Jamrozik K, Norman PE, Spencer CA, Parsons RW, Tuohy R, Lawrence-Browne MM, Dickinson JA. University of Western Australia. Perth, WA, Med J Aust 2000: 173; 345-50
6. Grimshaw GM, Thompson JM, Hamer JD. A statistical analysis of the growth of small abdominal aortic aneurysms. Eur J Vasc Surg 1994; 8: 741-6
7. Wilmink TB, Quick CR, Hubbard CS, Day NE. Institute of Public Health, University of Cambridge, Department of Surgery, Cambridge, CB2 2SR, United Kingdom. The influence of screening on the incidence of ruptured abdominal aortic aneurysms. J Vasc Surg 1999 Aug;30(2):203-8
8. Vardulaki KA, Prevost TC, Walker NM, Day NE, Wilmink AB, Quick CR, Ashton HA, Scott RA. Institute of Public Health, University of Cambridge, UK. Growth rates and risk of rupture of abdominal aortic aneurysms. Br J Surg 1998 Dec;85(12):1674-80
9. Wilmink AB, Pleumeekers HJ, Hoes AW, Hubbard CS, Grobbee DE, Quick CR. Institute of Public Health, University of Cambridge, U.K. The infrarenal aortic diameter in relation to age: only part of the population in older age groups shows an increase. Eur J Vasc Endovasc Surg 1998 Nov;16(5):431-7
10. Fowkes MR, Ruckley CV, Powell JT, Greerihalgh RM. Screening for abdominnl aortic aneurysms.Brit Med J 1992;.305: 1013
11. PIeumeekers HJCM, Hoes AW, van der Does E et al. Epidemioloqy of abdominal aortic aneurysms. Eur J Vasc Surg 1994; 8: 119-28
12. MacSweeney STR, O'Meara M, Alexander C, et al High prevalence of unsuspected ahdominal aortic anonrysms in patients with confirmed symptornatic peripheral or cerebral arterial disease. Br J Surg 1993; 80: 582-4
13. Pleumeekers HJ, Hoes AW, Hofman A, van Urk H, van der Does E, Grobbee DE. Department of Epidemiology & Biostatistics, Erasmus University Medical School, Rotterdam, The Netherlands. firstname.lastname@example.org Selecting subjects for ultrasonographic screening for aneurysms of the abdominal aorta: four different strategies. Int J Epidemiol 1999 Aug;28(4):682-6
14. Vardulaki KA, Prevost TC, Walker NM, Day NE, Wilmink AB, Quick CR, Ashton HA, Scott RA. Institute of Public Health, University of Cambridge, UK. Incidence among men of asymptomatic abdominal aortic aneurysms: estimates from 500 screen detected cases. J Med Screen 1999;6(1):50-4
15. Naydeck BL, Sutton-Tyrrell K, Schiller KD, Newman AB, Kuller LH. Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pennsylvania 15261, USA. email@example.com Prevalence and risk factors for abdominal aortic aneurysms in older adults with and without isolated systolic hypertension. Am J Cardiol 1999 Mar 1;83(5):759-64
16. Wilmink TB, Quick CR, Day NE. Department of Surgery, Addenbrooke's Hospital, Cambridge, UK. The association between cigarette smoking and abdominal aortic aneurysms. J Vasc Surg 1999 Dec;30(6):1099-105
17. Khaira HS, Herbert LM, Crowson MC. Department of Surgery, Good Hope Hospital NHS Trust, Sutton Coldfield, West Midlands. Screening for abdominal aortic aneurysms does not increase psychological morbidity. Ann R Coll Surg Engl 1998 Sep;80(5):341-2
3. The Rate of AAA Expansion
1. Grimshaw GM, Thompson JM, Hamer JD. A statistical analysis of the growth of small abdominal aortic aneurysms. Eur J Vasc Surg 1994; 8: 741-6
2. Gerdes LU, Lindholt JS, Vammen S, Henneberg EW, Fasting H. Department of Clinical Biochemistry, Aarhus University Hospital, Denmark. Apolipoprotein E genotype is associated with differential expansion rates of small abdominal aortic aneurysms. Br J Surg 2000 Jun;87(6):760-5
3. Lederle FA, Johnson GR, Wilson SE, Littooy FN, Krupski WC, Bandyk D, Acher CW, Chute EP, Hye RJ, Gordon IL, Freischlag J, Averbook AW, Makaroun MS. Aneurysm Detection and Management Veterans Affairs Cooperative Study Investigators. Department of Medicine, Veterans Affairs Medical Center, Minneapolis, Minn 55417, USA. Yield of repeated screening for abdominal aortic aneurysm after a 4-year interval. Arch Intern Med 2000 Apr 4;160(8):1117-21
4. Pleumeekers HJ, Hoes AW, Mulder PG, van der Does E, Hofman A, Lameris JS, Grobbee DE. Erasmus University Rotterdam, The Netherlands. Differences in observer variability of ultrasound measurements of the proximal and distal abdominal aorta. J Med Screen 1998;5(2):104-8
5. Schmidt MH, Mitchell JR, Downey DB. Department of Diagnostic Radiology, University of Western Ontario, London. Sonographic surveillance of abdominal aortic aneurysms: what is the smallest change in measured diameter that reliably reflects aneurysm growth? Can Assoc Radiol J 1999 Aug;50(4):241-6
6. Lindholt JS, Vammen S, Juul S, Henneberg EW, Fasting H. Department of Vascular Surgery, Hospital of Viborg, Denmark. The validity of ultrasonographic scanning as screening method for abdominal aortic aneurysm. Eur J Vasc Endovasc Surg 1999 Jun;17(6):472-5
7. Santilli SM, Wernsing SE, Lee ES. Vascular Surgery Section, VAMC, Minneapolis, MN 55417, USA. Expansion rates and outcomes for iliac artery aneurysms. J Vasc Surg 2000 Jan;31(1 Pt 1):114-21
8. Diwan A, Sarkar R, Stanley JC, Zelenock GB, Wakefield TW. Section of Vascular Surgery, Department of Surgery, University of Michigan Medical Center, Ann Arbor, USA. Incidence of femoral and popliteal artery aneurysms in patients with abdominal aortic aneurysms. J Vasc Surg 2000 May;31(5):863-9
4. The Evolution of Treatment for AAA
1. Ernst CB. Abdominal aortic aneurysm. New Engl J Med 1993; 328: 1167-72
2. Rutherford RB. Vascular Surgery. Philadelphia, WB Saunders, 1989.
3. Michael JA. Tile management of small abdominal aortic aneurysms: a computer simulation using Monte Carlo methods. Eur J Vasc Surg 1992; 6: 551-7
4. Dubost C, Allary M, Oeconomos N. Resection of an aneurysm of the abdominal aorta. Reestablishment of the continuity by a preserved human arterial graft; result after five months. Arch Surg 1952; 64: 405-8
5. Benzaquen BS, Eisenberg MJ, Challapalli R, Nguyen T, Brown KJ, Topol EJ. Department of Cardiology, Cleveland Clinic Foundation, OH, USA. Correlates of in-hospital cost among patients undergoing abdominal aortic aneurysm repair. Am Heart J 1998 Oct;136(4 Pt 1):696-702
6. Parodi JC, Palmaz JC, Barone HD. Transfemoral intraluminal graft implantation for abdominal aortic aneurysms. Ann Vasc Surg. 1991; 5: 491-9.
7. Lawrence-Brown M, Sieunarine K, Hartley D et al. The Perth HLB bifurcated endoluminal graft: A review of the experience and intermediate results. Cardiovasc. Surg. 1998; 6: 220-5.
8. May J, White GH. Yu W et al. Concurrent comparison of endoluminal versus open repair in the treatment of abdominal aortic aneurysms: Analysis of 303 patients by life table analysis. J. Vasc Surg. 1998; 27: 213-20.
9. Becquemin J-P, Bourriez A, D'Audiffret A et al. Mid-term results of endovascular versus open repair for abdominal aortic aneurysm in patients anatomically suitable for endovascular repair. Eur. J. Vase Endovasc. Surg. 2000; 19: 656-61.
10. Chuter TA, Gordon RL, Reilly LM, Kerlan RK, Sawhney R, Jean-Claude J, Canto CJ, LaBerge JM, Ring EJ, Wall SD, Messina LM. Department of Surgery, University of California, San Francisco 94143, USA. Abdominal aortic aneurysm in high-risk patients: short- to intermediate-term results of endovascular repair. Radiology 1999 Feb;210(2):361-5
11. Cuypers P, Buth J, Harris PL, Gevers E, Lahey R. Realistic expectations for patients with stmt-graft treatment of abdominal aortic aneurysms. Results of a European multicentre registry. Eur. J. Vasc. Endovasc. Surg. 1999; 17: 507-16.
12. Blum U, Voshage G, Lammer J et al. Endoluminal stmt-grafts for infrarenal abdominal aortic aneurysms. N. Engl. J. Med. 1997; 336: 13-20.
13. Moore WS, Kashyap VS, Vescera CL, Quinones-Baldrich WJ. Abdominal aortic aneurysm: A 6-year comparison of endovascular versus transabdominal repair. Ann. Surg. 1999; 230: 298-306.
14. May J, White GH, Waugh R, et al. Endovascular treatment of abdominal aortic aneurysms. Cardiovasc Surg. 1999;7:484-490.
15. Stelter W, Umscheid T, Ziegler P. Three-year experience with modular stent-graft devices for endovascular AAA treatment. J Endovasc Surg. 1997;4:362-369.
16. Elobato AC, Rodriguez-Lopez J, Ramaiah VG, Vranic M, Diethrich EB. Learning curve for endovascular AAA repair: Evaluation in a large, single-center experience. J. Endovnsc. Ther. 2000; 7 (Suppl.): 122-3.
17. May J, White GH, Waugh R, Stephen MS, Chaufour X, Yu W, Harris JP. Department of Surgery, University of Sydney, Royal Prince Alfred Hospital, Sydney, Australia. Adverse events after endoluminal repair of abdominal aortic aneurysms: a comparison during two successive periods of time. J Vasc Surg 1999 Jan;29(1):32-7; discussion 38-9
18. Morikage N, Esato K, Zenpo N, Fujioka K, Takenaka H. First Department of Surgery, Yamaguchi University School of Medicine, Yamaguchi 755-8505, Japan. Is endovascular treatment of abdominal aortic aneurysms less invasive regarding the biological responses? Surg Today 2000;30(2):142-6
19. Finlayson SR, Birkmeyer JD, Fillinger MF, Cronenwett JL. VA Outcomes Group, Department of Veterans Affairs Medical Center, White River Junction, VT, USA. Should endovascular surgery lower the threshold for repair of abdominal aortic aneurysms? J Vasc Surg 1999 Jun;29(6):973-85
20. Abou-Zamzam AM, Porter JM. Division of Vascular Surgery, Oregon Health Sciences University, Portland 97201-3098, USA. Does endovascular grafting represent a giant step forward? Semin Vasc Surg 1999 Sep;12(3):235-41
21. Harris P, Brennan J, Martin J, et al. Longitudinal aneurysm shrinkage following endovascular aortic aneurysm repair: a source of immediate and late complications. J Endovasc Surg. 1999;6:11-16.
22. White GH, May J, Waugh R, et al. Shortening of endografts during deployment in endovascular AAA repair. J Endovasc Surg. 1999;6:4-10.
23. Umscheid T, Stelter WJ. Time-related alterations in shape, position, and structure in selfexpanding, modular aortic stent-grafts: a 4year single-center follow-up. J Endovasc Surg. 1999;6: 7 7-32.
24. May J, White GH, Harris JP. Department of Surgery, University of Sydney, Australia. Devices for aortic aneurysm repair. Surg Clin North Am 1999 Jun;79(3):507-27
25. May J, White GH, Waugh R, Petrasek P et al. Life-table analysis of primary and assisted success following endoluminal repair of abdominal aortic aneurysms: The role of supplementary endovascular intervention in improving outcome. Eur. J. Vase Endova.sc. Surg. 2000; 19: 648-55.
26 Buth J, Laheij RJ. EUROSTAR Data Registry Center, Department of Vascular Surgery, Catharina Hospital, 5602 Eindhoven, The Netherlands. Early complications and endoleaks after endovascular abdominal aortic aneurysm repair: report of a multicenter study. Abdom Imaging 2000 Jan-Feb;25(1):59-61
27. Harris PL. The highs and lows of endovascular aneurysm repair: the first two years of the Eurostar Registry. Ann R Coll Surg Engl. 1999;81: 161-165.
28. Cuypers P, Buth J, Harris PL, et al. Realistic expectations for patients with stent-graft treatment of abdominal aortic aneurysms. Results of a European multicentre registry. Eur J Vasc Endovasc Surg. 1999;17:507-516.
29. Harris PL. Regional Vascular Unit, Royal Liverpool University Hospital, UK. The highs and lows of endovascular aneurysm repair: the first two years of the Eurostar Registry. Ann R Coll Surg Engl 1999 May;81(3):161-5
30. Cuypers P, Buth J, Harris PL, Gevers E, Lahey R. EUROSTAR Data Registry Centre, Department of Vascular Surgery, Eindhoven, The Netherlands. Realistic expectations for patients with stent-graft treatment of abdominal aortic aneurysms. Results of a European multicentre registry. Eur J Vasc Endovasc Surg 1999 Jun;17(6):507-16
31. Thomas SM, Gaines PA, Beard JD. Vascular Society of Great Britain and Ireland: BETA: the registry of endovascular treatment of abdominal aortic aneurysms. Br J Surg. 1999;86:711.
32. Thomas SM, Gaines PA, Beard JD on behalf of the Vascular Surgical Society of Great Britain and Ireland and the British Society of Interventional Radiology. Short-term (30-day) outcome of endovascular treatment of abdominal aortic aneurysm: results from the prospective registry of endovascular treatment of abdominal aortic aneurysms (RETA). Eur J Vasc Endovasc Surg 2001: 21 ; 57-64
33. Harris PL, Buth J. Regarding "Problems with the dissemination of up-to-date information on the results of endograft repair for abdominal aortic aneurysm. J Vasc Surg. 1999;30:767768.
34. Rutherford RB. Regarding "problems with the dissemination of up-to-date information on the results of endograft repair for abdominal aortic aneurysms." J Vasc Surg. 1999;30:768-769.
35. Myers KA. How will endoluminal grafting for aneurysms be judged? J Endovasc Ther. 2000; 7: 101.
36. Treharne GD, Thompson MM, Whiteley MW, et al. Vascular Surgical Society of Great Britain and Ireland: endovascular aortic aneurysm repair reduces mortality: a physiological analysis. Br J Surg. 1999;86:697.
5. Techniques for Open Surgical Repair for AAA
1. Kirby LB, Rosenthal D, Atkins CP, Brown GA, Matsuura JH, Clark MD, Pallos L. Georgia Baptist Medical Center, Division of Health Studies Center for Disease Control, Atlanta, 30312, USA. Comparison between the transabdominal and retroperitoneal approaches for aortic reconstruction in patients at high risk. J Vasc Surg 1999 Sep;30(3):400-5
2. Quinones-Baldrich WJ, Garner C, Caswell D, Ahn SS, Gelabert HA, Machleder HI, Moore WS. Department of Vascular Surgery, UCLA Medical Center, Los Angeles, CA, Endovascular, transperitoneal, and retroperitoneal abdominal aortic aneurysm repair: results and costs. J Vasc Surg 1999 Jul;30(1):59-67
3. Martin GH, O'Hara PJ, Hertzer NR, Mascha EJ, Krajewski LP, Beven EG, Clair DG, Ouriel K. Department of Vascular Surgery, Cleveland Clinic Foundation, Ohio, USA. Surgical repair of aneurysms involving the suprarenal, visceral, and lower thoracic aortic segments: early results and late outcome. J Vasc Surg 2000 May;31(5):851-62
4. Faggioli G, Stella A, Freyrie A, Gargiulo M, Tarantini S, Rodio M, Pilato A, D'Addato M. Dipartimento di Scienze Chirurgiche e Anestesiologiche, Universita di Bologna, Italy. Early and long-term results in the surgical treatment of juxtarenal and pararenal aortic aneurysms. Eur J Vasc Endovasc Surg 1998 Mar;15(3):205-11
5. Kniemeyer HW, Kessler T, Reber PU, Ris HB, Hakki H, Widmer MK. Department of Vascular Surgery, Clinic of Thoracic, Cardiac and Vascular Surgery, Switzerland. Treatment of ruptured abdominal aortic aneurysm, a permanent challenge or a waste of resources? Prediction of outcome using a multi-organ-dysfunction score. Eur J Vasc Endovasc Surg 2000 Feb;19(2):190-6
6. Miani S, Giorgetti PL, Giordanengo F, Tealdi D. Institute of General and Cardiovascular Surgery, University of Milan, Italy. Ruptured abdominal aortic aneurysms: factors affecting the early postoperative outcome. Panminerva Med 1998 Dec;40(4):309-13
6. Techniques for ELG for AAA
1. Edwards WH, Naslund TC. Saint Thomas Hospital, Department of Surgery, Vanderbilt University School of Medicine, Nashville, TN, USA. Bifurcated devices in the treatment of abdominal aortic aneurysms: limitations and advantages of a single-component bifurcated prosthesis. Semin Vasc Surg 1999 Sep;12(3):165-9
2. Barras CD, Myers KA. Departments of Vascular Surgery, Monash Medical Centre and Epworth Hospital, Melbourne, Australia. Nitinol - its use in vascular surgery and other applications. Eur J Vasc Endovasc Surg 2000 Jun;19(6):564-9
3. Parodi JC, Palmaz JC, Barone HD. Transfemoral intraluminal graft implantation for abdominal aortic aneurysms. Ann Vasc Surg. 1991; 5: 491-9.
4. Mialhe C, Amicabile C. Polyclinique Notre-Dame, Draguignan. Endovascular treatment of aneurysms of the subrenal aorta using the Stentor endoprosthesis. Preliminary series. J Mal Vasc 1995;20(4):290-5
5. May J, White GH, Waugh R, Stephen MS, Chaufour X, Arulchelvam M, Harris JP. Department of Surgery, University of Sydney, Sydney, Australia. Comparison of first- and second-generation prostheses for endoluminal repair of abdominal aortic aneurysms: a 6-year study with life table analysis. J Vasc Surg 2000 Jul;32(1):124-9
6. Blum U, Voshage G, Lammer J, Beyersdorf F, Tollner D, Kretschmer G, Spillner G, Polterauer P, Nagel G, Holzenbein T. Department of Diagnostic Radiology, University Hospital, Freiburg, Germany. Endoluminal stent-grafts for infrarenal abdominal aortic aneurysms. N Engl J Med 1997 Jan 2;336(1):13-20
7. Becquemin JP, Lapie V, Favre JP, Rousseau H . Hospital Henri Mondor, University Paris XII, Creteil, 94000, France. Mid-term results of a second generation bifurcated endovascular graft for abdominal aortic aneurysm repair: the French Vanguard trial. J Vasc Surg 1999 Aug;30(2):209-18
8. Mialhe C, Amicabile C, Becquemin JP. Polyclinique Notre-Dame, Draguignan, France. Endovascular treatment of infrarenal abdominal aneurysms by the Stentor system: preliminary results of 79 cases. Stentor Retrospective Study Group. J Vasc Surg, 1997 Aug; 26(2):199-209
9. Lundbom J, Hatlinghus S, Wirsching J, Amundsen S, Staxrud LE, GjLlberg T, Hafsahl G, Oskarsson W, Krohg-SLrensen K, Brekke M, Myhre HO. Department of Surgery, University Hospital of Trondheim, Norway. Endovascular treatment of abdominal aortic aneurysms in Norway: the first 100 patients. Eur J Vasc Endovasc Surg 1999 Dec;18(6):506-9
10. Criado FJ, Fry PD, Machan LS, Twena M, Patten P. Division of Vascular Surgery/Endovascular Program, Union Memorial Hospital/Helix Health, Baltimore, MD, USA. The Talent endoluminal AAA stent-graft system. Report of the phase I USA trial, and summary of worldwide experience. J Mal Vasc 1998 Dec;23(5):371-3
11. Hausegger KA, Mendel H, Tiessenhausen K, Kaucky M, Aman W, Tauss J, Koch G. Department of Radiology, University of Graz, Austria. Endoluminal treatment of infrarenal aortic aneurysms: clinical experience with the Talent stent-graft system. J Vasc Interv Radiol 1999 Mar;10(3):267-74
12. Uflacker R, Robison JG, Brothers TE, Pereira AH, Sanvitto PC. Department of Radiology, Medical University of South Carolina, Charleston 29425, USA. Abdominal aortic aneurysm treatment: preliminary results with the Talent stent-graft system. J Vasc Interv Radiol 1998 Jan-Feb;9(1 Pt 1):51-60
13. Velazquez OC, Larson RA, Baum RA, Carpenter JP, Golden MA, Mitchell ME, Pyeron A, Barker CF, Fairman RM. Hospital of the University of Pennsylvania, University of Pennsylvania School of Medicine. Gender-related differences in infrarenal aortic aneurysm morphologic features: Issues relevant to Ancure and Talent endografts. J Vasc Surg 2001 Feb;33(2 Pt 2):77-84
14. Chavan A, Cohnert TU, Heine J, Dresler C, Leuwer M, Harringer W, Jorgensen M, Haverich A, Galanski M. Department of Diagnostic Radiology, Hannover Medical School, Germany. Endoluminal grafting of abdominal aortic aneurysms: experience with the Talent endoluminal stent graft. Eur Radiol 2000;10(4):636-41
15. Treiman GS, Lawrence PF, Edwards WH, Galt SW, Kraiss LW, Bhirangi K. Division of Vascular Surgery, University of Utah School of Medicine, Salt Lake City, UT 84132, USA. An assessment of the current applicability of the EVT endovascular graft for treatment of patients with an infrarenal abdominal aortic aneurysm. J Vasc Surg 1999 Jul;30(1):68-75
16. Sarkar R, Moore WS, Quinones-Baldrich WJ, Gomes AS. Division of Vascular Surgery, UCLA Medical Center, Los Angeles, California 90095-6904, USA. Endovascular repair of abdominal aortic aneurysm using the EVT device: limited increased utilization with availability of a bifurcated graft. J Endovasc Surg 1999 May;6(2):131-5
17. Makaroun MS. Division of Vascular Surgery, University of Pittsburgh School of Medicine. The Ancure endografting system: An update. J Vasc Surg 2001 Feb;33(2 Pt 2):129-134
18. Zarins CK, White RA, Schwarten D, Kinney E, Diethrich EB, Hodgson KJ, Fogarty TJ. Division of Vascular Surgery, Stanford University Medical Center, California, USA. AneuRx stent graft versus open surgical repair of abdominal aortic aneurysms: multicenter prospective clinical trial. J Vasc Surg 1999 Feb;29(2):292-305; discussion 306-8
19. Biasi GM, Piglionica MR, Meregaglia D, Ferrari SA, Cao PG, Barzi F, Verzini F, Coppi G, Pacchioni R, Gennari S, Moll FL, Nolthenius RP, van der Berg JC, Stancanelli V, Piccinini E, White R, Allen R. Department of Vascular Surgery and Radiology, Bassini Hospital, University of Milan, Italy. European multicentre experience with modular device (Medtronic Aneurx) for the endoluminal repair of infrarenal abdominal aortic aneurysms. J Mal Vasc 1998 Dec;23(5):374-80
20. Nolthenius RP, Berg JC, Biasi GM, Piglionica MR, Meregaglia D, Ferrari SA, Coppi G, Pacchioni R, Gennai S, Cao P, Barzi F, Verzini F, Maselli A, Caporali S, Moll FL. Department of Vascular Surgery, St Antonius Hospital, Nieuwegein, The Netherlands. Endoluminal repair of infrarenal abdominal aortic aneurysms using a modular stent-graft: one-year clinical results from a European multicentre trial. Cardiovasc Surg 1999 Aug;7(5):503-7
21. Lawrence-Brown M, Sieunarine K, Hartley D et al. The Perth HLB bifurcated endoluminal graft: A review of the experience and intermediate results. Cardiovasc. Surg. 1998; 6: 220-5.
22. White RA. Division of Vascular Surgery, Harbor-UCLA Medical Center. Clinical and design update on the development and testing of a one-piece, bifurcated, polytetra-fluoroethylene endovascular graft for abdominal aortic aneurysm exclusion: The Endologix device. J Vasc Surg 2001 Feb;33(2 Pt 2):154-156
23. Myers KA, Devine TJ. Endoluminal Grafting for Abdominal Aortic Aneurysms: Stretching the Limits. Epworth Hospital and Monash Medical Centre, Melbourne, Australia. J. Tokyo Med. Univ., 56 (2), 1998
24. Browne TF, Hartley D, Purchas S, Rosenberg M, Van Schie G, Lawrence-Brown M. Department of Surgery, Broomfield Hospital, Chelmsford, Essex, UK. A fenestrated covered suprarenal aortic stent. Eur J Vasc Endovasc Surg 1999 Nov;18(5):445-9
25. Anderson JL, Berce M, Hartley DE. Ashford Community Hospital, South Australia, Australia. firstname.lastname@example.org Endoluminal aortic grafting with renal and superior mesenteric artery incorporation by graft fenestration. J Endovasc Ther 2001 Feb;8(1):3-15
26. Stanley BM, Semmens JB, Lawrence-Brown MM, Goodman MA, Hartley DE. Endovascular Unit, Royal Perth Hospital, Western Australia. Fenestration in endovascular grafts for aortic aneurysm repair: new horizons for preserving blood flow in branch vessels. J Endovasc Ther 2001 Feb;8(1):16-24
27. Inoue K, Hosokawa H, Iwase T, Sato M, Yoshida Y, Ueno K, Tsubokawa A, Tanaka T, Tamaki S, Suzuki T. Department of Cardiovascular Surgery, Takeda Hospital, Kyoto, Japan. email@example.com Aortic arch reconstruction by transluminally placed endovascular branched stent graft. Circulation 1999 Nov 9;100(19 Suppl):II316-21
28. Chuter TA, Gordon RL, Reilly LM, Goodman JD, Messina LM. Department of Surgery, University of California San Francisco, USA. firstname.lastname@example.org An endovascular system for thoracoabdominal aortic aneurysm repair. J Endovasc Ther 2001 Feb;8(1):25-33
7. Preoperative Measurement of AAAs for ELG
1. Beebe HG, Kritpracha B, Serres S, Pigott JP, Price CI, Williams DM. Jobst Vascular Center, Toledo, OH 43606 USA. email@example.com Endograft planning without preoperative arteriography: a clinical feasibility study. J Endovasc Ther 2000 Feb;7(1):8-15
2. Qanadli SD, Mesurolle B, Coggia M, Barre O, Fukui S, Goeau-Brissonniere OA, Chagnon S, Lacombe P. Department of Radiology, University Rene Descartes-Paris V, Hopital Ambroise Pare, Boulogne, France. Abdominal aortic aneurysm: pretherapy assessment with dual-slice helical CT angiography. Am J Roentgenol 2000 Jan;174(1):181-7
3. Armon MP, Whitaker SC, Gregson RH, Wenham PW, Hopkinson BR. Department of Vascular and Endovascular Surgery, University Hospital, Nottingham, United Kingdom. firstname.lastname@example.org Spiral CT angiography versus aortography in the assessment of aortoiliac length in patients undergoing endovascular abdominal aortic aneurysm repair. J Endovasc Surg 1998 Aug;5(3):222-7
4. Resch T, Ivancev K, Lindh M, Nirhov N, Nyman U, Lindblad B. Department of Radiology, Malmo University Hospital, Lund University, Sweden. email@example.com Abdominal aortic aneurysm morphology in candidates for endovascular repair evaluated with spiral computed tomography and digital subtraction angiography. J Endovasc Surg 1999 Aug;6(3):227-32
5. Aarts NJ, Schurink GW, Schultze Kool LJ, Bode PJ, van Baalen JM, Hermans J, van Bockel JH. Department of Radiology, Leiden University Medical Centre, Leiden, The Netherlands. Abdominal aortic aneurysm measurements for endovascular repair: intra- and interobserver variability of CT measurements. Eur J Vasc Endovasc Surg 1999 Dec;18(6):475-80
6. Blomley MJ, McBride A, Mohammedtagi S, Albrecht T, Harvey CJ, Jager R, Standfield NJ, Dawson P. Department of Radiology, Hammersmith Hospital, London, UK. firstname.lastname@example.org Functional renal perfusion imaging with colour mapping: is it a useful adjunct to spiral CT of in the assessment of abdominal aortic aneurysm (AAA)? Eur J Radiol 1999 Jun;30(3):214-20
7. Rubin GD, Armerding MD, Dake MD, Napel S, Department of Radiology, Stanford University School of Medicine, Stanford, CA 94305-5105, USA. email@example.com Cost identification of abdominal aortic aneurysm imaging by using time and motion analyses. Radiology 2000 Apr;215(1):63-70
8. Schoenberg SO, Wunsch C, Knopp MV, Essig M, Hawighorst H, Laub G, Prince MR, Allenberg JR, Van Kaick G. Department of Radiology, German Cancer Research Center, Heidelberg, Germany. Abdominal aortic aneurysm. Detection of multilevel vascular pathology by time-resolved multiphase 3D gadolinium MR angiography: initial report. Invest Radiol 1999 Oct;34(10):648-59
9. Ludman CN, Yusuf SW, Whitaker SC, Gregson RH, Walker S, Hopkinson BR. Department of Academic Radiology, University Hospital, Nottingham, UK. Feasibility of using dynamic contrast-enhanced magnetic resonance angiography as the sole imaging modality prior to endovascular repair of abdominal aortic aneurysms. Eur J Vasc Endovasc Surg 2000 May;19(5):524-30
10. Wallis F, Roditi GH, Redpath TW, Weir J, Cross KS, Smith FW. The Department of Diagnostic Imaging, Aberdeen Royal Infirmary, Foresterhill, Aberdeen, AB25 2ZD, Scotland, U.K. Inflammatory abdominal aortic aneurysms: diagnosis with gadolinium enhanced T1-weighted imaging. Clin Radiol 2000 Feb;55(2):136-9
11. van Essen JA, Gussenhoven EJ, van der Lugt A, Huijsman PC, van Muiswinkel JM, van Sambeek MR, van Dijk LC, van Urk H. Departments of Cardiology, Erasmus University Medical Center, Rotterdam, The Netherlands. Accurate assessment of abdominal aortic aneurysm with intravascular ultrasound scanning: validation with computed tomographic angiography. J Vasc Surg 1999 Apr;29(4):631-8
8. Selection for Treatment for AAAs
1. Ludemann R, Swanstrom LL. Department of Minimally Invasive Surgery, Legacy Health System, Portland, OR, USA. Totally laparoscopic abdominal aortic aneurysm repair. Semin Laparosc Surg 1999 Sep;6(3):153-63
2. Edoga JK, James KV, Resnikoff M, Asgarian K, Singh D, Romanelli J. Department of Surgery, Morristown Memorial Hospital, New Jersey, USA. Laparoscopic aortic aneurysm resection. J Endovasc Surg 1998 Nov;5(4):335-44
3. Hallett JW. Division of Vascular Surgery, Mayo Clinic Rochester, Minn. 55905, USA. Management of abdominal aortic aneurysms. Mayo Clin Proc 2000 Apr;75(4):395-9
4. Mohan IV, Harris PL. The Royal Liverpool University Hospital, Liverpool, UK. When not to operate for abdominal aortic aneurysms. Semin Interv Cardiol 2000 Mar;5(1):15-9
5. Walker SR, Macierewicz J, MacSweeney ST, Gregson RH, Whitaker SC, Wenham PW, Hopkinson BR. Department of Vascular and Endovascular Surgery, Queen's Medical Centre, Nottingham, United Kingdom. firstname.lastname@example.org Mortality rates following endovascular repair of abdominal aortic aneurysms. J Endovasc Surg 1999 Aug;6(3):233-8
6. Greenberg RK, Srivastava SD, Ouriel K, Waldman D, Ivancev K, Illig KA, Shortell C, Green RM. Department of Vascular Surgery, The Cleveland Clinic Foundation, Ohio 44195, USA. email@example.com An endoluminal method of hemorrhage control and repair of ruptured abdominal aortic aneurysms. J Endovasc Ther 2000 Feb;7(1):1-7
7. Ohki T, Veith FJ. Department of Surgery, Montefiore Medical Center, and the Albert Einstein College of Medicine, New York, NY 10467, USA. Patient selection for endovascular repair of abdominal aortic aneurysms: changing the threshold for intervention. Semin Vasc Surg 1999 Sep;12(3):226-34
8. Sarkar R, Moore WS, Quinones-Baldrich WJ, Gomes AS. Division of Vascular Surgery, UCLA Medical Center, Los Angeles, California 90095-6904, USA. Endovascular repair of abdominal aortic aneurysm using the EVT device: limited increased utilization with availability of a bifurcated graft. J Endovasc Surg 1999 May;6(2):131-5
9. Treiman GS, Lawrence PF, Edwards WH, Galt SW, Kraiss LW, Bhirangi K. Division of Vascular Surgery, University of Utah School of Medicine, Salt Lake City, UT 84132, USA. An assessment of the current applicability of the EVT endovascular graft for treatment of patients with an infrarenal abdominal aortic aneurysm. J Vasc Surg 1999 Jul;30(1):68-75
10. Kalliafas S, Albertini JN, Macierewicz J, Yusuf SW, Whitaker SC, Macsweeney ST, Wenham PW, Hopkinson BR. Division of Vascular Surgery, Nottingham University Hospital, United Kingdom. Incidence and treatment of intraoperative technical problems during endovascular repair of complex abdominal aortic aneurysms. J Vasc Surg 2000 Jun;31(6):1185-92
11. Wolf YG, Fogarty TJ, Olcott C IV, Hill BB, Harris EJ, Mitchell RS, Miller DC, Dalman RL, Zarins CK, Division of Vascular Surgery, Stanford University Medical Center, Stanford, CA, USA. Endovascular repair of abdominal aortic aneurysms: eligibility rate and impact on the rate of open repair. J Vasc Surg 2000 Sep;32(3):519-23
12. Velazquez OC, Larson RA, Baum RA, Carpenter JP, Golden MA, Mitchell ME, Pyeron A, Barker CF, Fairman RM. Hospital of the University of Pennsylvania, University of Pennsylvania School of Medicine. Gender-related differences in infrarenal aortic aneurysm morphologic features: Issues relevant to Ancure and Talent endografts. J Vasc Surg 2001 Feb;33(2 Pt 2):77-84
13. Kaplan DB, Kwon CC, Marin ML, Hollier LH. Mount Sinai Medical Center, Cleveland, Ohio, USA. Endovascular repair of abdominal aortic aneurysms in patients with congenital renal vascular anomalies. J Vasc Surg 1999 Sep;30(3):407-15
14. Loftus IK, Thompson MM, Fishwick G, Boyle JR, Bell PR. Department of Surgery, University of Leicester, United Kingdom. firstname.lastname@example.org Endovascular repair of aortic aneurysms in the the presence of a horseshoe kidney. J Endovasc Surg 1998 Aug;5(3):278-81
15. Nevelsteen A, Lacroix H, Stockx L, Baert L, Depuydt P. Center for Vascular Diseases, the Department of Vascular Surgery, UZ Gasthuisberg, Leuven, Belgium. Inflammatory abdominal aortic aneurysm and bilateral complete ureteral obstruction: treatment by endovascular graft and bilateral ureteric stenting. Ann Vasc Surg 1999 Mar;13(2):222-4
9. Complications and Results after Open Surgical Repair for AAA
1. Campbell WB Mortality statistics for elective aortic aneurysms Eur J Vasc Surg 1991; 5: 111-3
2. Akkersdijk GJ, van der Graaf Y, Moll FL, de Vries AC, Kitslaar PJ, van Bockel JH, Hak E, Eikelboom BC. Department of Surgery, University Hospital Leiden, The Netherlands. Complications of standard elective abdominal aortic aneurysm repair. Eur J Vasc Endovasc Surg 1998 Jun;15(6):505-10
3. Sasaki S, Takigami K, Kunihara T, Shiiya N, Murashita T, Matsui Y, Yasuda K. Department of Cardiovascular Surgery, Hokkaido University Hospital, Sapporo, Japan. Abdominal aortic aneurysms in aged patients: analysis of risk factors in non-ruptured cases. J Cardiovasc Surg (Torino) 1999 Feb;40(1):1-5
4. Cappeller WA, Holzel D, Hinz MH, Lauterjung L. Department of Surgery and Institute for Medical Informatik, Klinikum Grosshadern, Ludwig-Maximilians-Universitat Munchen, Germany. Ten-year results following elective surgery for abdominal aortic aneurysm. Int Angiol 1998 Dec;17(4):234-40
5. Adam DJ, Ludlam CA, Ruckley CV, Bradbury AW. Vascular Surgery Unit, University Department of Clinical and Surgical Sciences, Royal Infirmary, Edinburgh, Scotland, United Kingdom. Coagulation and fibrinolysis in patients undergoing operation for ruptured and nonruptured infrarenal abdominal aortic aneurysms. J Vasc Surg 1999 Oct;30(4):641-50
6. Holmberg A, Bergqvist D, Siegbahn A. Department of Surgical and Medical Sciences, University Hospital Uppsala, Sweden. email@example.com Coagulation and fibrinolysis after open infrarenal abdominal aortic aneurysm repair in a long-term perspective. Thromb Res 1999 Oct 15;96(2):99-105
7. Sakakibara Y, Takeda T, Hori M, Mitsui T, Ijima H. Department of Surgery, Institute of Clinical Medicine, University of Tsukuba, Ibaraki, Japan. Disseminated intravascular coagulation in aortic aneurysms: assessment of consumption site using labeled-platelet scintigraphy. Thorac Cardiovasc Surg 1999 Jun;47(3):162-5
8. Faggioli G, Stella A, Freyrie A, Gargiulo M, Tarantini S, Rodio M, Pilato A, D'Addato M. Dipartimento di Scienze Chirurgiche e Anestesiologiche, Universita di Bologna, Italy. Early and long-term results in the surgical treatment of juxtarenal and pararenal aortic aneurysms. Eur J Vasc Endovasc Surg 1998 Mar;15(3):205-11
9. Miani S, Giorgetti PL, Giordanengo F, Tealdi D. Institute of General and Cardiovascular Surgery, University of Milan, Italy. Ruptured abdominal aortic aneurysms: factors affecting the early postoperative outcome. Panminerva Med 1998 Dec;40(4):309-13
10. Quigley FG, Clark D, Avramovic. Cardiac assessment with thallium scanning prior to aortic aneurysm repair. J Cardiovasc Surg 1999 Oct;7(6):640-4
10. Complications after ELG for AAA
1. White GH, May J, Waugh RC, Yu W. Type I and Type II endoleaks: a more useful classification for reporting results of endoluminal AAA repair. J Endovasc Surg 1998 May;5(2):189-91
2. White GH, May J, Waugh RC, Chaufour X, Yu W. Department of Vascular Surgery, Royal Prince Alfred Hospital, University of Sydney, NSW, Australia. firstname.lastname@example.org Type III and type IV endoleak: toward a complete definition of blood flow in the sac after endoluminal AAA repair. J Endovasc Surg 1998 Nov;5(4):305-9
3. White GH, May J, Petrasek P, Waugh R, Stephen M, Harris J. Department of Vascular Surgery, Royal Prince Alfred Hospital, University of Sydney, NSW, Australia. email@example.com Endotension: an explanation for continued AAA growth after successful endoluminal repair. J Endovasc Surg 1999 Nov;6(4):308-15
4. Albertini J, Kalliafas S, Travis S, Yusuf SW, Macierewicz JA, Whitaker SC, Elmarasy NM, Hopkinson BR. Vascular and Endovascular Surgery Department, Queen's Medical Centre, Nottingham, UK. Anatomical risk factors for proximal perigraft endoleak and graft migration following endovascular repair of abdominal aortic aneurysms. Eur J Vasc Endovasc Surg 2000 Mar;19(3):308-12.
5. Makaroun M, Zajko A, Sugimoto H, Eskandari M, Webster M. Division of Vascular Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA, USA. Fate of endoleaks after endoluminal repair of abdominal aortic aneurysms with the EVT device. Eur J Vasc Endovasc Surg 1999 Sep;18(3):185-90
6. Schurink GW, Aarts NJ, van Baalen JM, Schultze Kool LJ, van Bockel JH. Department of Surgery, Leiden University Medical Center, The Netherlands. Stent attachment site-related endoleakage after stent graft treatment: An in vitro study of the effects of graft size, stent type, and atherosclerotic wall changes. J Vasc Surg 1999 Oct;30(4):658-67
7. Holzenbein TJ, Kretschmer G, Dorffner R, Thurnher S, Sandner D, Minar E, Lammer J, Polterauer P. Department of Vascular Surgery, Vienna University Hospital, Austria. Endovascular management of "endoleaks" after transluminal infrarenal abdominal aneurysm repair. Eur J Vasc Endovasc Surg 1998 Sep;16(3):208-17
8. Makaroun M, Zajko A, Sugimoto H, Eskandari M, Webster M. Division of Vascular Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA, USA. Fate of endoleaks after endoluminal repair of abdominal aortic aneurysms with the EVT device. Eur J Vasc Endovasc Surg 1999 Sep;18(3):185-90
9. Walker SR, Macierewicz J, Hopkinson BR. Department of Vascular and Endovascular Surgery, Queen's Medical Centre, Nottingham, United Kingdom. firstname.lastname@example.org Endovascular AAA repair: prevention of side branch endoleaks with thrombogenic sponge. J Endovasc Surg 1999 Nov;6(4):350-3
10. Baum RA, Carpenter JP, Tuite CM, Velazquez OC, Soulen MC, Barker CF, Golden MA, Pyeron AM, Fairman RM. Section of Interventional Radiology, Department of Radiology, University of Pennsylvania, PA 19104, USA. email@example.com Diagnosis and treatment of inferior mesenteric arterial endoleaks after endovascular repair of abdominal aortic aneurysms. Radiology 2000 May;215(2):409-13
11. Tibballs JM, van Schie GP, Sieunarine K, Lawrence-Brown MM, Hartley D, Goodman MA, Prendergast FJ. Department of Radiology, Royal Perth Hospital, GPO Box X2213, Perth 6001, Western Australia. Endovascular conversion procedure for failed primary endovascular aortic stent-grafts. Cardiovasc Intervent Radiol 1998 Jan-Feb;21(1):79-83
12. Matsumura JS, Chaikof EL. Department of Surgery, Northwestern University Medical School, Chicago, IL, USA. Anatomic changes after endovascular grafting for aneurysmal disease. Semin Vasc Surg 1999 Sep;12(3):192-8
13. Wolf YG, Hill BB, Rubin GD, Fogarty TJ, Zarins CK. Division of Vascular Surgery and the Department of Radiology, Stanford University Hospital, Stanford, CA 94305-5642, USA. Rate of change in abdominal aortic aneurysm diameter after endovascular repair. J Vasc Surg 2000 Jul;32(1):108-15
14. White GH, May J, Waugh R, Harris JP, Chaufour X, Yu W, Stephen MS. Department of Vascular Surgery, Royal Prince Alfred Hospital, University of Sydney, NSW, Australia. firstname.lastname@example.org Shortening of endografts during deployment in endovascular AAA repair. J Endovasc Surg 1999 Feb;6(1):4-10
15. Wever JJ, Blankensteijn JD, Broeders IA, Eikelboom BC. Department of Surgery, University Hospital Utrecht, The Netherlands. Length measurements of the aorta after endovascular abdominal aortic aneurysm repair. Eur J Vasc Endovasc Surg 1999 Dec;18(6):481-6
16. Umscheid T, Stelter WJ. Department of Surgery, Stadtische Kliniken Frankfurt-Hochst, Frankfurt, Germany. email@example.com Time-related alterations in shape, position, and structure of self-expanding, modular aortic stent-grafts: a 4-year single-center follow-up. J Endovasc Surg 1999 Feb;6(1):17-32
17. Sonesson B, Resch T, Lanne T, Ivancev K. Department of Vascular and Renal Diseases and the Department of Radiology, Lund University, Malmo University Hospital, Sweden. The fate of the infrarenal aortic neck after open aneurysm surgery. J Vasc Surg 1998 Nov;28(5):889-94
18. Matsumura JS, Chaikof EL. Department of Surgery, Northwestern University Medical School, Chicago, Ill, USA. Continued expansion of aortic necks after endovascular repair of abdominal aortic aneurysms. EVT Investigators. EndoVascular Technologies, Inc. J Vasc Surg 1998 Sep;28(3):422-30; discussion 430-1
19. May J, White GH, Yu W, Waugh R, Stephen MS, Arulchelvam M, Harris JP. Importance of graft configuration in outcome of endoluminal aortic aneurysm repair: a 5-year analysis by the life table method. Eur J Vasc Endovasc Surg, 1998 May; 15(5):406-411
20. Wever JJ, de Nie AJ, Blankensteijn JD, Broeders IA, Mali WP, Eikelboom BC. Department of Vascular Surgery, University Medical Center, Utrecht, The Netherlands. Dilatation of the proximal neck of infrarenal aortic aneurysms after endovascular AAA repair. Eur J Vasc Endovasc Surg 2000 Feb;19(2):197-201
21. Sonesson B, Malina M, Ivancev K, Lindh M, Lindblad B, Brunkwall J. Department of Vascular and Renal Diseases, Lund University, Malmo University Hospital, Sweden. Dilatation of the infrarenal aneurysm neck after endovascular exclusion of abdominal aortic aneurysm. J Endovasc Surg 1998 Aug;5(3):195-200
22. Resch T, Ivancev K, Brunkwall J, Nyman U, Malina M, Lindblad B. Department of Radiology, Malmo University Hospital, Sweden. Distal migration of stent-grafts after endovascular repair of abdominal aortic aneurysms. J Vasc Interv Radiol 1999 Mar;10(3):257-64; discussion 265-6
23. Cuypers PW, Laheij RJ, Buth J. EUROSTAR Data Registry Center, Catharina Hospital, Eindhoven, The Netherlands.Which factors increase the risk of conversion to open surgery following endovascular abdominal aortic aneurysm repair? The EUROSTAR collaborators. Eur J Vasc Endovasc Surg 2000 Aug;20(2):183-9
24. May J, White GH, Harris JP. Department of Surgery, University of Sydney, Royal Prince Alfred Hospital, New South Wales, Australia. Early and late conversion from endoluminal to open repair. Semin Vasc Surg 1999 Sep;12(3):207-14
25. May J, White GH, Yu W, Waugh R, Stephen MS, Chaufour X, Harris JP. Department of Surgery University of Sydney, New South Wales, Australia. Endovascular grafting for abdominal aortic aneurysms: changing incidence and indication for conversion to open operation. Cardiovasc Surg 1998 Apr;6(2):194-7
26. Barras CDJ. Comparative study of open and endovascular techniques for abdominal aortic aneurysm repair. B Med Sci Thesis. Monash University, Melbourne, Victoria, Australia. 1997.
27. Odegard A, Lundbom J, Myhre HO, Hatlinghus S, Bergh K, Waage A, Bjerve KS, Mollnes TE, Aadahl P, Lie TA, Videm V. Department of Radiology, Regional Hospital of Trondheim, Norway. The inflammatory response following treatment of abdominal aortic aneurysms: a comparison between open surgery and endovascular repair. Eur J Vasc Endovasc Surg 2000 May;19(5):536-44
28. Morikage N, Esato K, Zenpo N, Fujioka K, Takenaka H. First Department of Surgery, Yamaguchi University School of Medicine, Yamaguchi 755-8505, Japan. Is endovascular treatment of abdominal aortic aneurysms less invasive regarding the biological responses? Surg Today 2000;30(2):142-6
29. Elmarasy NM, Soong CV, Walker SR, Macierewicz JA, Yusuf SW, Wenham PW, Hopkinson BR. Department of Vascular and Endovascular Surgery, Queen's Medical Centre, Nottingham, United Kingdom. firstname.lastname@example.org Sigmoid ischemia and the inflammatory response following endovascular abdominal aortic aneurysm repair. J Endovasc Ther 200 Feb;7(1):21-30
30. Syk I, Andreasson A, Truedsson L, Risberg B. Department of Surgery, Malmo University Hospital, Sweden. Postoperative downregulation of MHC class II antigen on monocytes does not differ between open and endovascular repair of aortic aneurysms. Eur J Surg 1999 Nov;165(11):1035-42
31. Malina M, Brunkwall J, Lindblad B, Resch T, Ivancev K. Department of Vascular Surgery, Lund University, Malmo University Hospital, Sweden Endovascular management of the juxtarenal aortic aneurysm: can uncovered stents safely cross the renal arteries? Semin Vasc Surg 1999 Sep;12(3):182-91
32. Jaeger HJ, Mathias KD, Gissler HM, Neumann G, Walther LD. Department of Diagnostic Radiology, Stadtische Kliniken Dortmund, Germany. Rectum and sigmoid colon necrosis due to cholesterol embolization after implantation of an aortic stent-graft. J Vasc Interv Radiol 1999 Jun;10(6):751-5
33. Walker SR, Yusuf SW, Wenham PW, Hopkinson BR. Department of Vascular and Endovascular Surgery, Queen's Medical Center, Nottingham, United Kingdom. Renal complications following endovascular repair of abdominal aortic aneurysms. J Endovasc Surg 1998 Nov;5(4):318-22
34. Henretta JP, Hodgson KJ, Mattos MA, Karch LA, Hurlbert SN, Sternbach Y, Ramsey DE, Sumner DS. Section of Peripheral Vascular Surgery, Department of Surgery, Southern Illinois University School of Medicine, Springfield, USA. Feasibility of endovascular repair of abdominal aortic aneurysms with local anesthesia with intravenous sedation. J Vasc Surg 1999 May;29(5):793-8
11. Results after ELG for AAA
1. May J, White GH, Waugh R, Stephen MS, Chaufourt X, Yu W, Harris JP. Endovascular treatment of abdominal aortic aneurysms. Department of Surgery, University of Sydney, New South Wales, Australia. Cardiovasc Surg 1999 Aug;7(5):484-90
2. May J, White GH, Yu W, Ly CN, Waugh R, Stephen MS, Arulchelvam M, Harris JP. Department of Surgery, University of Sydney, Royal Prince Alfred Hospital, NHMRC Clinical Trials Centre, New South Wales, Australia. Concurrent comparison of endoluminal versus open repair in the treatment of abdominal aortic aneurysms: analysis of 303 patients by life table method. J Vasc Surg, 1998 Feb; 27(2):213-220
3. May J, White GH, Waugh R, Petrasek P, Chaufour X, Arulchelvam M, Stephen MS, Harris JP. Department of Surgery, University of Sydney, Australia. Life-table analysis of primary and assisted success following endoluminal repair of abdominal aortic aneurysms: the role of supplementary endovascular intervention in improving outcome. Eur J Vasc Endovasc Surg 2000 Jun;19(6):648-55
4. Kalliafas S, Albertini JN, Macierewicz J, Yusuf SW, Whitaker SC, Macsweeney ST, Wenham PW, Hopkinson BR. Division of Vascular Surgery, Nottingham University Hospital, United Kingdom. Incidence and treatment of intraoperative technical problems during endovascular repair of complex abdominal aortic aneurysms. J Vasc Surg 2000 Jun;31(6):1185-92
5. Walker SR, Macierewicz J, MacSweeney ST, Gregson RH, Whitaker SC, Wenham PW, Hopkinson BR. Department of Vascular and Endovascular Surgery, Queen's Medical Centre, Nottingham, United Kingdom. email@example.com Mortality rates following endovascular repair of abdominal aortic aneurysms. J Endovasc Surg 1999 Aug;6(3):233-8
6. Buth J, Laheij RJ. EUROSTAR Data Registry Center, Department of Vascular Surgery, Catharina Hospital, 5602 Eindhoven, The Netherlands. Early complications and endoleaks after endovascular abdominal aortic aneurysm repair: report of a multicenter study. Abdom Imaging 2000 Jan-Feb;25(1):59-61
7. Zarins CK, White RA, Schwarten D, Kinney E, Diethrich EB, Hodgson KJ, Fogarty TJ. Division of Vascular Surgery, Stanford University Medical Center, California, USA. AneuRx stent graft versus open surgical repair of abdominal aortic aneurysms: multicenter prospective clinical trial. J Vasc Surg 1999 Feb;29(2):292-305; discussion 306-8
8. Nolthenius RP, Berg JC, Biasi GM, Piglionica MR, Meregaglia D, Ferrari SA, Coppi G, Pacchioni R, Gennai S, Cao P, Barzi F, Verzini F, Maselli A, Caporali S, Moll FL. Department of Vascular Surgery, St Antonius Hospital, Nieuwegein, The Netherlands. Endoluminal repair of infrarenal abdominal aortic aneurysms using a modular stent-graft: one-year clinical results from a European multicentre trial. Cardiovasc Surg 1999 Aug;7(5):503-7
9. Makaroun MS. Division of Vascular Surgery, University of Pittsburgh School of Medicine. The Ancure endografting system: An update. J Vasc Surg 2001 Feb;33(2 Pt 2):129-134
10. Greenberg RK, Lawrence-Brown M, Bhandari G, Hartley D, Stelter W, Umscheid T, Chuter T, Ivancev K, Green R, Hopkinson B, Semmens J, Ouriel K. Department of Vascular Surgery, Cleveland Clinic Foundation, Ohio 44195, USA. An update of the Zenith endovascular graft for abdominal aortic aneurysms: initial implantation and mid-term follow-up data. J Vasc Surg 2001 Feb;33(2 Suppl):S157-64
12. Surveillance after ELG for AAA
1. Karch LA, Henretta JP, Hodgson KJ, Mattos MA, Ramsey DE, McLafferty RB, Sumner DS. Section of Peripheral Vascular Surgery, Southern Illinois University School of Medicine, Springfield, USA. Algorithm for the diagnosis and treatment of endoleaks. Am J Surg 1999 Sep;178(3):225-31
2. Armerding MD, Rubin GD, Beaulieu CF, Slonim SM, Olcott EW, Samuels SL, Jorgensen MJ, Semba CP, Jeffrey RB, Dake MD, Department of Radiology, Stanford University School of Medicine, Stanford University Medical Center, Stanford, CA 94305-5105, USA. Aortic aneurysmal disease: assessment of stent-graft treatment-CT versus conventional angiography. Radiology 2000 Apr;215(1):138-46
3. Sato DT, Goff CD, Gregory RT, Robinson KD, Carter KA, Herts BR, Vilsack HB, Gayle RG, Parent FN, DeMasi RJ, Meier GH. Division of Vascular Surgery, Eastern Virginia Medical School, and the Core Laboratory for the Endovascular Aneurysm Clinical Trial, Norfolk 23510, USA. Endoleak after aortic stent graft repair: diagnosis by color duplex ultrasound scan versus computed tomography scan. J Vasc Surg 1998 Oct;28(4):657-63
4. Fletcher J, Saker K, Batiste P, Dyer S. Department of Surgery, University of Sydney and Westmead Vascular Laboratory, Westmead, NSW, Australia. Colour Doppler diagnosis of perigraft flow following endovascular repair of abdominal aortic aneurysm. Int Angiol 2000: 19; 326-30.
5. d'Audiffret A, Desgranges P, Kobeiter DH, Becquemin J-P. Dept of Vascular Surgery and Dept. of Imaging, centre Hospitalier Universitaire Henri Mondor, Paris, France. Follow-up evaluation of endoluminally treated abdominal aortic aneurysms with duplex ultrasonography: validation with computed tomography. J Vasc Surg 2001: 33; 42-50
13. Comparison of Costing for Open Repair and ELG
1. Heikkinen M, Salenius JP, Auvinen O. Department of Surgery, University Hospital, Tampere, Finland. Projected workload for a vascular service in 2020. Eur J Vasc Endovasc Surg 2000 Apr;19(4):351-5
2. Mackey LG, Merriel RB, Myers KA. The financial impact of an endoluminal stenting procedure. Aust. Health Rev. 1998; 21: 130-8.
3. Barras CDJ. Comparative study of open and endovascular techniques for abdominal aortic aneurysm repair. B Med Sci Thesis. Monash University, Melbourne, Victoria, Australia. 1997.
4. Birch SE, Stary DR, Scott AR, Department of Surgery, Launceston General Hospital, Tasmania, Australia. Cost of endovascular versus open surgical repair of abdominal aortic aneurysms. Aust N Z J Surg 2000 Sep;70(9):660-6
5. Quinones-Baldrich WJ, Garner C, Caswell D, Ahn SS, Gelabert HA, Machleder HI, Moore WS. Department of Vascular Surgery, UCLA Medical Center, Los Angeles, CA, Endovascular, transperitoneal, and retroperitoneal abdominal aortic aneurysm repair: results and costs. J Vasc Surg 1999 Jul;30(1):59-67
6. Quinones-Baldrich WJ. Department of Vascular Surgery, UCLA Center for the Health Sciences, Los Angeles, CA 90095-6904, USA. Achieving cost-effective endoluminal aneurysm repair. Semin Vasc Surg 1999 Sep;12(3):220-5
7. Sternbergh WC, Money SR. Ochsner Clinic and Foundation, New Orleans, LA 70121, USA. Hospital cost of endovascular versus open repair of abdominal aortic aneurysms: a multicenter study. J Vasc Surg 2000 Feb;31(2):237-44
8. Clair DG, Gray B, O'hara PJ, Ouriel K. Departments of Vascular Surgery and Vascular Medicine, The Cleveland Clinic Foundation, Cleveland, OH 44195, USA. An evaluation of the costs to health care institutions of endovascular aortic aneurysm repair. J Vasc Surg 2000 Jul;32(1):148-52
9. Patel ST, Haser PB, Bush HL, Kent KC. Department of Surgery, Division of Vascular Surgery, New York Presbyterian Hospital, Cornell University Medical College, New York 10021, USA. The cost-effectiveness of endovascular repair versus open surgical repair of abdominal aortic aneurysms: A decision analysis model. J Vasc Surg 1999 Jun;29(6):958-72
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2nd Virtual Congress of Cardiology
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