Single-center experience of the surgical treatment
of ascending aorta in Córdoba, Argentina.
GERMÁN J CHAUD, EZEQUIEL WAINSCHEINKER, PABLO A FILIPPA, ANDRÉS PARISI,
GUILLERMO PALADINI, ALEJANDRO MARTÍNEZ COLOMBRES.
Hospital Privado Universitario de Córdoba
(5000) Córdoba, Argentina. E-mail
Recibido 21-MAR-2018 – ACEPTADO despues de revision el 06-MAYO-2018.
There are no conflicts of interest to disclose.
INTRODUCTION: The goal of ascending aortic aneurysm surgery is to prevent the risk of dissection or rupture, which in 30% of cases leads to the death of the patient. Advances in surgical techniques made it possible to completely resect the affected aorta and replace it with synthetic or biological conduits. Over time, surgical risk has decreased and long-term evolution reveals a survival rate with a very low incidence of complications with respect to it, except in patients over 60 years of age, whose risk is still above 30%. The primary objective was to know early mortality (before 30 days or at hospital discharge) in patients who underwent ascending aorta surgery, and their comparisons between elective and emergency procedures. Secondarily, major complications were analyzed between elective and emergency procedures such as stroke; acute renal failure and reoperation due to bleeding, as well as stay in the Critical Care Unit. MATERIAL and METHODS: Retrospective, descriptive review of adult patients who underwent surgery at the Private University Hospital of Córdoba, due to ascending aortic pathology, both electively and urgently, from January 2010 to December 2016. RESULTS The analysis of the data revealed a mortality of 4.83% (3/62) in the elective group and 27.7% (5/18) in the emergency surgery group, with an overall mortality of 10%. CONCLUSIONS: Mortality from surgery of the ascending aorta has improved in recent years; however, it still carries a risk close to 30%, especially in cases of emergency and in patients older than 70 years.
INTRODUCCIÓN The main goal of surgery of ascending aorta aneurysms (AAA) is to restore its normal dimensions and thus, prevent the risk of dissection or rupture, which leads in a large percentage of cases, to the death of patients. According to the European guidelines on the treatment of diseases of the aorta, surgery should be considered in patients with aorta aneurysm with maximum diameters of 45 mm with Marfan syndrome, 50 mm with bicuspid valve, and 55 mm in patients with no previous diseases or collagenopathies[1-3]. Further, the risk of complications related to aneurysms (rupture, dissection and death) according to its size in relation to the body surface of the patient is well known. The incidence of aortic dissection in the world is estimated in 0.5 to 2.95 every 100,000 inhabitants per year, mainly in men. Different advancements in surgical techniques and the development of new materials made the full resection of the affected aorta possible, as well as its replacement with synthetic and biological conduits. Over time, the surgical risk associated to the replacement of the ascending aorta has decreased substantially, and long-term evolution reveals a survival with very low incidence of complications with respect to it. According to a review conducted in the United States, early mortality after elective ascending aorta replacement is 3.4%; however, it significantly increases when the procedure is made in patients of more than 60 years, with multiple cardiovascular co-morbidities to even up to 20%; and with no treatment of it, it reaches 90% in 15 days[4,5].
Multiple techniques have been described for the treatment of this pathology. If the aneurysm is limited to the sinotubular junction with normal valve function and with no dilatation of the aortic annulus or valve insufficiency secondary to aortic dilatation, ascending aorta resection is the fastest and most effective method to correct it. However, if the aneurysm extends proximally below the sinotubular junction and one of more aortic sinuses are dilated generating valve insufficiency, the surgical repair is based on aortic annulus and aortic valve compromise as Yacoub describes it. Before a case of tricuspid aortic valve with no regurgitation or central regurgitation due to annulus dilatation as in patients with Marfan syndrome, valve preservation should be done with annular reduction, with techniques such as David’s technique with reimplantation of the aortic valve within a synthetic tube, or the modified Yacoub’s method, well proven by Dr. Shaffer et al, in their description of aortic remodeling and annular plastic surgery. Finally, before patients with annular dilatations greater than 45 mm of diameter, valve diseases not likely to dilate or before the technical impossibility of repair in the medical center, we should not forget the gold standard and the still classical technique of Bentall, with the latter being a mechanical valve or a biological valve[1,5,8,9].
New anesthetic techniques have led to a more widespread use of transesophageal echo, monitoring, perfusion and valve function, as well as deep hypothermia, circulatory arrest and neuroprotective drugs as management. The most frequently used technique for brain protection during ascending aorta and aortic arch surgery is still deep hypothermia with circulatory arrest[2,10,11].
In spite of the previously mentioned advancements, mortality in these patients, even in centers with high incidence and experience, is still around 25%[12-16].
Recently, endovascular treatments have been published for the ascending aorta; however, they have only been evaluated in isolated cases, not showing great benefits and still with risks (endoleaks, stroke, AMI, splenic artery embolization, etc.) that we ignore how they will evolve[17,18]. In spite of what was explained above, great advancements have been achieved on the hybrid treatment of this pathology, although there are no randomized studies comparing treatment strategies. Different advantages of it include not using deep hypothermia and its association with coagulopathies and bleeding, complete resection and exclusion of intimal tear, decrease in cerebral ischemia, avoiding circulatory arrest and removal of residual tears in the aortic arch.
About this, with the passing of years the marked difference in the mortality of elective surgeries and emergency surgeries has been proven, which leads to a great morbidity with a high number of hospitalization days and great expenses for the health care systems.
We show through this review, our 6-year experience in a single center of the interior of Argentina in the treatment of ascending aorta pathologies, both urgent or elective, which is necessary to learn, to establish if international recommendations are appropriate to our environment or whether we should generate our own parameters to thus achieve a better implementation of them in our patients.
MATERIALS AND METHODS A retrospective, descriptive review was made through searches in digital clinical histories, with the prior consent of the department of education and investigation of the hospital, of all adult patients surgically intervened at the Hospital Privado Universitario de Córdoba, due to pathology of the ascending aorta, both elective or urgent (up to 14 days after the onset of symptoms) between January 2010 and December 2016.
Adult patients were included (older than 18 years) in whom aortic valve and ascending aorta treatment was made, or the latter in isolation. Patients in whom coronary artery bypass was made in association to the main procedure were included; while patients in whom mitral or tricuspid valve treatment was made were ruled out.
Presurgical variables were considered (age, gender, hypertension (HTN), diabetes mellitus (DM), peripheral vascular disease, bicuspid or tricuspid valve, previous aortic size, previous use of clopidogrel or anticoagulation (AC)), intraoperative variables (time of extracorporeal circulation (ECC) and clamping, time of circulatory arrest (CA) and type of surgery performed) and postsurgical variables (death, prolonged ventilation, infections, reoperation due to bleeding, atrial fibrillation (AF), acute renal failure (ARF), atrioventricular block (AVB), stroke).
All interventions are made through median sternotomies.
The election of artery cannulation was made based on specific factors of the patient, including extension of dissection, poor perfusion, hemodynamic instability (shock or tamponade), age, peripheral vascular disease and history of previous stroke. Venous cannulation was made in the right atrium through a two-stage cannula or in the femoral vein in selected cases, mainly urgencies. In such cases, when it was necessary to perform circulatory arrest, temperature was taken to 18°C (deep hypothermia), and selective antegrade artery cannulation was applied for cerebral protection through the right brachiocephalic trunk. In all patients, biological glue was used to reinforce anastomotic areas.
We define variables as: acute aortic dissection as that diagnosed within the first 15 days after the appearance of symptoms; prolonged ventilation in patients in whom it was more than 8 hours; stroke/transient ischemic attack (TIA) was defined as new neurological focus confirmed by CT or NMR, being permanent or less than 24 h of duration respectively; and early mortality within 30 days after the surgical procedure or before hospital discharge.
The primary aim was to establish early mortality (before 30 days or at hospital discharge) in patients undergoing ascending aorta surgery, and its comparison between elective and emergency procedures. The secondary aim was to analyze morbidity as major complications like stroke, acute renal failure (ARF), acute myocardial infarction (AMI) and reoperation by bleeding between the scheduled and emergency procedures, and other factors as for instance, stay in the Critical Care Unit, thus assuming by multivariate logistic regression analysis, which are the risk factors contributing directly to mortality increase. Finally, we will correlate presurgical aortic diameters with risks of dissection and postsurgical death.
The statistical analysis was made with the IBM SPSS Statistics 21 software for Windows.
RESULTS The analysis of the demographic characteristics of the study showed that from the total of 80 patients, the mean age was 56.79 years (range 9-77 years). Male gender was predominant with 58 cases (72.5%). Sixty-one patients presented HTN previously (76.3%), bicuspid aortic valve in 28 patients (35%). Only 1 (1.3%) patient had indication of presurgical AC and 3 (3.8%) consumed clopidogrel at the time of surgery.
The types of surgery made were Bentall in 46 (57.5%) cases, ascending aorta replacement (AAR) in 14 (17.5%), aortic valve replacement (AVR) + AAR in 17 (21.3%) and Yacoub surgery (3.8%), which are shown in Figure 1.
The analysis of data revealed in relation to the primary aim, a general mortality of 10% (8/80) of patients, from whom 4.83% (3/62) corresponded to the elective surgery group and 27.7% (5/18) to the emergency surgery group with a significant P of 0.004.
The results of presurgical variables for the elective surgery group (62-77.5%) and the emergency surgery group (18-22.5%) were male gender 44 (70.96%) and 14 (77.7%) P: 0.57; age 56 years and 58 years P: 0.57; older than 70 years 8/62 (12.9%) and 5/18 (27.7%) P: 0.13. In those older than 70 years, overall mortality was 75% in 6/8 patients. HTN was present in 47 (77.05%) and 14 (22.95%) respectively, with P: 0.86.
Only one patient of the elective surgery group had aortic dissection, a finding that led to the intervention. Sixty patients (96.7%) and 3 (16.67%) presented ascending aortic aneurysm, respectively, P: 0.0001. Bicuspid aortic valve was identified in 26 (25.8%) patients and in 2 (11%), P: 0.16, respectively. From the bicuspid aortic valves, 16 were stenosis, 5 insufficiencies and 7 mixed types. Only 3 patients in the emergency surgery group had previous indication of antiaggregation with clopidogrel (16.7%); while no one in the elective group, with significant P: 0.001; and 1 patient (5.5%) had previous indication of AC in the emergency group; and no one in the elective surgery group, P: 0.062. The last case is included between the deceased patients and had bleeding complications
The mean of aortic size in general, was 51.31 mm (minimum 36 mm – maximum 80 mm), for the elective group was 51.24 mm, and for the emergency surgery group, 52.25 mm. The results are shown in Table 1.
Table 1. Presurgical variables
Older than 70 years
Presurgical Hb in mg /dL
Intraoperative data are shown in Table 2, which are the following for the elective and emergency surgeries, respectively: ECC times were 144 min vs 185 min, P: 0.005; clamping: 116 min vs 127 min, p: 0.35; three (22%) required circulatory arrest vs 14 (77.7%) respectively, with P: 0.0001.
From the total of patients, 6 (9.7%) from the first group underwent only ascending aorta replacement vs 8 (44.4%), P: 0.002 of the second group. Aortic valve replacement plus ascending aorta replacement was necessary in 17 (27.4%) of the first group and none of the second; P: 0.002. Bentall surgery was conducted in 37 (59.67%) vs 9 (50%), P: 0.002. Yacoub surgery was made in 2 patients electively (3.22%) vs 1 as an emergency surgery (5.5%), P: 0.002. From all patients, 6 (9.67%) underwent coronary bypass in the first group vs 2 (11.11%) in the second group, P: 0.86.
Finally, postoperative variables, as well as major complications were analyzed and shown in Table 3. Atrial fibrillation was detected in 18 patients (29.03%) of the elective group vs 4 (22.2%) of the emergency surgery group, respectively P: 0.57. Acute renal failure (ARF), 3 (4.83%) vs 10 (55.5%), P: 0.0001. Three (22%) presented stroke vs 2 (11%), P: 0.038; of the latter, 2/5 (40%) correspond to >70 years, P: 0.13. Six (9.6%) presented AV block vs 2 (11.1%), P: 0.85. Eight (12.9%) in the elective surgery group presented prolonged ventilation vs 10 (55.5%) of the emergency surgery group with a significant P of 0.0001. Re-exploration due to bleeding in 4 patients (6.45%) vs 1 (5.5%), P: 0.89. Pericardial effusion in 6 (9.67%) vs 8 (44%), P: 0.001. Pleural effusion in 4 (6.45%) vs 2 (11.1%), P: 0.52. Urinary tract infection (UTI) in 2 (3.22%) patients of the elective group vs 2 (11.1%) of the emergency surgery group, P: 0.17; hospital-acquired pneumonia (HAP) in 3 (22.2%) vs 7 (38.8%), P: 0.001.
Table 3. Postsurgical variables
Myocardial revascularization surgery
Acute renal failure
Reexploration due to bleeding
Urinary tract infection
Intensive Care Unit
Postsurgical Hb in mg/dL
The Coronary Unit stay days were analyzed for both groups, with a mean of 4 days for the elective surgery group and 18 days for the emergency group with P: 0.0001, as well as the hemoglobin (Hb) value before and after surgery, and its relation to the modality of procedure performed (Figure 2).
Finally, logistic regression analysis was made with postsurgical Hb, AF, ARF, stroke, composite procedures, prolonged ventilation, and state of the procedure (emergency vs elective), not generating the same significant difference between variables.
DISCUSSION In international literature, Griepp et al, in a series of 443 patients with replacement of ascending aorta reported an overall mortality (including elective and emergency surgeries) of 9%. In another series published by Elefteriades et al, in which there were 506 patients included, reported an overall mortality of 8.6% in elective surgeries 3%, and in emergency surgeries 19.7%. In the paper presented by Lu et al, mortality was analyzed in patients undergoing aortic arch replacement due to acute vs chronic dissection, in-hospital mortality in acute cases was 11.2%; while in the chronic cases, it was 9%. The main causes described include renal, liver, and respiratory failure, infections, low output syndrome, gastrointestinal bleeding, as well as neurological complications, which reached 10.9% in acute cases and 9% in chronic cases. The latter does differ from our results, which showed a greater predisposition to stroke in the elective group with 22% vs 11.1% in the emergency group with P: 0.038. The latter is probably due to greater aortic calcification in the group of patients with stroke as they were mostly elderly.
Estrera et al, published an analysis and comparison of surgical treatment of typical acute dissection, with dissection plus intramural hematoma, and mortality between both did not vary significantly, 14% vs 11%. Narayan et al, included patients with type A dissection, reported an overall mortality of 18.2%, which is greater than that reported in our experience. Likewise, in the IRAD study, a 26% of postoperative mortality was described. Okada et al, showed an overall mortality of 4.4% and mortality of elective surgery of 1.9%, including in their study, total replacement of aortic arch. Easo et al, published in a study derived from the GERAADA, 18.7% mortality in acute type A dissection with aortic arch compromise, about which we did not find any reference in our series during the term of evaluation. Shuyang Lu et al, reported 11.2% mortality vs 9% on 267 patients in acute vs chronic aortic dissection, respectively. All of the above agrees with 4.83% mortality in elective surgery, 27.7% in urgencies and 10% of overall mortality in our center. However, when assessing mortality by age group, we found it to be greater in patients older and younger than 70 years than those published by Gilon et al, of 37.5% and 23%, respectively, as in our experience mortality in people older than 70 years was 75%; P: 0.0001, assuming the most of them correspond to the emergency surgery group.
Between the main causes of early mortality in the bibliography, the following are described: heart failure, multiple organ failure, neurological causes, bleeding and poor splenic perfusion. Likewise, patients have been described with previous heart surgery, cardiac tamponade in shock, preoperative evidence of stroke, and poor coronary, viscera or peripheral perfusion, who tend to present worse results over the course of acute type A aortic dissection[15,22]. Perrault et al, in 2012 showed that cardiogenic shock, cerebral ischemia and massive bleeding were responsible for at least 85% of perioperative deaths. Likewise, a poor distal perfusion may manifest at iliofemoral, mesenteric, renal, cerebral level, or at the spinal cord since the onset. At least 20 to 30% of patients that present type A dissection could have one or more poor perfusion syndromes. According to the group of Pacini, the average of mortality in acute type A dissection was at least 3 times higher in the poor perfusion group. In our registry, we could not show a statistical significance for the cause of death in relation to the latter.
It has been widely demonstrated that the size of the ascending aorta larger than 50 mm is a factor that directly increases morbidity and mortality. In our study, we reported a general mean aortic diameter of 51.24 mm, in the emergency surgeries of 52.25 mm and in elective surgeries of 51 mm, which although it does not statistically show to be causal, should be used logically in terms of its correlation to a poor evolution, which maybe, should lead us to evaluate in our area, whether we should use aortic diameters to guide us according to international parameters, or if we should establish a lower aortic diameter based on regional characteristics to prevent complications.
Numerous articles have described by multivariate logistic regression, the main independent factors that contribute to mortality in this group of patients, among them an age greater than 70 years (odds ratio 1.7 CI 95%), permanent neurological deficit, chronic renal failure, and reoperation[11,16,22,23]. The multivariate logistic regression analysis of the population studied did not find significant differences between the different variables analyzed, possible because of the number of patients included in the sample.
The hospital stay reported is a mean of 13 days for emergency procedures within a 10-6 days range. About this, namely the stay in the Coronary Intensive Care Unit, we found a clear difference between elective procedures vs emergency procedures: 4 days vs 18 days with a significant P of 0.0001. As it is to be expected, a longer stay in emergency surgery cases translates into more significant complications, and therefore, greater hospital costs. This datum, added to morbidity and mortality, should be a warning sign when detecting cases, to decrease emergency surgeries and thus strengthen elective surgeries, achieving better results in our patients, and simultaneously decreasing health care costs.
A great deal of evidence supports the fact that centers with a high surgical volume, even with management protocols before pathologies of such high complexity, decrease mortality improving results in the short and long term, so policies of this type are those that our institution works on with much emphasis, to improve their survival.
Finally, and in comparison to other studies, we found satisfactory results as to mortality and morbidity, both in elective procedures and emergency ones in our institution, which represents a great motivation to continue down this road, and thus generate policies of investigation that would help us to know what is the reality of our area and what parameters to take into account to prevent a possible fatal outcome in them.
The main one is that this is an observational, retrospective (as most studies on this topic) study, besides recording a low number of patients as this is a single-center study and from the interior of the country, in comparison to the main centers at world level.
CONCLUSIONS The mortality of ascending aorta surgery has improved in recent years; however, it entails a great risk, close to 30% mainly in emergency cases and in patients older than 70 years. Policies that would enable a higher velocity to manage these patients, as well as specialized teams, are necessary to decrease it and it is only possible to achieve this if we learn about the scenario in Argentina.
We would like to thank Marina Fernandez, member of the department of Investigation of the Hospital Privado Universitario de Córdoba for their collaboration in the logistics, writing and analysis of the statistical results.
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