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Intraortic Ballon Pump - A New Solution for an Old Problem

Almeida R.M.S.S.A.

Serviço de Cirurgia Cardiovascular
Instituto de Moléstias Cardiovasculares de Cascavel.
Cascavel. Paraná. Brasil

Abstract
Introduction
Objectives
Material and Methods
Results
Discussion
Conclusions
References

Abstract
Objetive: To show the post-operative results after intraortic ballon pump insertion with a new surgical technique.
Patients and Methods: Between August of 1994 and June of 1999, 1400 cardiac surgery procedures were performed, 931 of them being pump cases. Of this 32 (3,48%) had left ventricular assistance, with intra aortic balloon counterpulsation. The mean age was 55 years, being 19 (55%) males patients. Coronary artery disease was present in 22 (68.75%) patients. In 22 cases the balloon was installed as an emergency, being 16 in the operating room and 6 in the intensive care unit; in 10 (31.25%) it was installed electively. The insertion technique was performed by a surgical cut down to the femoral artery. A saphenous, homo or autologous, graft was then sewn to the common femoral artery in and end-to-side fashion. The balloon was introduced into the artery through the graft and properly positioned, and the balloon catether secured to the graft on it's the distal portion. The balloon removal was done with local anesthesia, and required no second operation, only by taking off the stitch securing the vein to the balloon, and bearing the vein, after it's occlusion.
Results: The overall survival was 47%, being 80% in the elective group. Mean pumping time was 54,5 hours for the survival group. In no case was the mortality due to the insertion technique, and the complication rate was 6,25%, due to severe peripheral vascular disease in two cases.
Conclusions: The authors conclude that this is a viable and easy reproducible technique, and has the advantage of not having to do another cut down, for balloon removal, or using prosthetic material.

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Introduction: After experimental studies of Claus et al1 and Moulopolus et al2, a new concept of aortic counterpulsation arose. Despite these studies it was not until 1966, that Kantrowitz et al3, published the first results with the intraaortic balloon pump (IABP). But it was only in the seventies that this method had its use widespread and reports came out with their advantages. Nowadays 2 to 12% of patients submitted to cardiac surgery use the IABP, bur still the primary pathology carries a high mortality risk, with reports showing 34 to 56%mortality. With the broadening of their indications and the improvements in technology, the mortality rates have decreased, and the IABP has become the simplest and easiest left ventricular (LV) counterpulsation method. In 1980 Bregman et al4 and Subramanian et al5 described a method for insertion of on IABP, know as the Seldinger technique6. Despite the fact this method is easy and reproducible, the international literature has shown a high risk of complications. In cardiac surgery and specially in the operating room (OR), it seems easy for a surgeon to perform a cut down and insert the IABP, under direct vision. Relaying on this fact the author describes a new technique for surgically inserting an IABP, which can be a solution for an old problem – the retrieval of the IABP sheet after its clinical case.

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Objectives:  The author evaluates the short and long term results after intraaortic balloon pump insertion, with a new surgical technique, and the survival of patients when this form of left ventricular assistance was allocated electively or as an emergency.

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Material and Methods:  Between July 1992 and June 1999, 1400 cardiac surgeries were performed, at the department of cardiovascular surgery of the "Instituto de Moléstias Cardiovasculares de Cascavel", being 931 of them with cardiopulmonary bypass. During this period, in 32 patients, an IABP was inserted due to cardiogenic shock or postcardiotomy low cardiac output. The mean age, was 59 years, with a range of 41 to 73 years, and 62,5% were male. In eighteen cases (56,3%) the indication for surgical treatment was, ischemic heart disease, in 11 cases (34,4%) valvular heart disease and in one case end stage cardiomyophathy (Table 1). In the ischemic heart disease group four patients (12,5%) were surgically treated, during the first 30 days post myocardial infarction, due to angina, and another four had left main coronary disease. Apart from their cardiac disease, chronic obstructive pulmonary disease was present in 18,8%, renal failure in 9,4%, diabetes in another 9,4%. Four cases (12,5%) were reoperations and twelve cases (37,5%) had a left ventricular ejection fraction below 40%. The population's mean weight was 68,2 kg, height 153 cm and body surface 173 cm2. All patients were submitted to a standard cardio-pulmonary by-pass surgery, and used St. Thomas cold cardioplegia, at 4ºC infused in the aortic root, repeated every 30 minutes. In these group the aortic valve was replaced by a biological one in six cases and by a mechanical one in two cases; the mitral valve was replaced by a biological prostheses in four cases and a mitral platy, with a Carpentier's ring, was performed once. In the ischemic heart disease group, on whom myocardial revascularization was performed, with or without other associated pathology, the internal mammary artery was used in ten cases to the left anterior descending coronary artery and in two cases to it's diagonal branch. The left radial artery was used in two cases, one to the right coronary artery and the other to the marginal branch of the circumflex artery. Autologous saphenous vein grafts were implanted forty-seven arteries, being 21 to the marginal branches of the circumflex artery, 14 to the right coronary artery, six to the left anterior descending coronary artery, five to its diagonal branch and one to a diagonalis coronary artery. Fourteen arterial conduits were used in 12 patients (37,5%), and the overall media was 2,61 conduits/patient. The total by-pass time was, in media, 110 min (50-178 min) and the cross clamp time was 51,6 min (20-106 min). Endarterectomy was performed in four cases, two to the LAD and one to the right coronary artery and the other to the circumflex's marginal branch. The mean hospital stay time was 16 days (ranging 9-25days). In 22 cases (68.8%) the balloon was installed as an emergency, i.e. the indication was sever low cardiac output and/or cardiogenic shock, being 16 in the OR and 6 in the intensive care unit. In 10 (31.3%) it was installed electively, in these cases the indication was poor LV function in high risk patients, and it was previewed and inserted pre-entering by-pass. In all cases the technique used to insert the IABP was the following one:

- With the patient under general anaesthesia or sedated, the left common femoral artery was dissected and repaired, in its proximal portion, as well as the proximal ones of the superficial and profound femoral arteries. With the patient heparinized and the three arteries clamped, a transverse incision on the anterior side of the common femoral, of no more than 1/4 of its circumference, was made, with a nº11 blade, artery. An IABP catether is passed through a segment of autologous saphenous vein, or homologous if the patient's vein is no available, of approximately five centimetres in length, through the femoral artery and positioned into the descending aorta, just below the left subclavian artery. The IABP is started, and then and only then, the vein graft is sewed to the femoral artery, by means of a 6-0 Prolene. The anastomosis' hill should be the first to be performed, due to its technical difficulties. A slight traction should be applied to the catether, so that a better view of the anastomosis could be obtained. The saphenous graft, at its distal end, is firmly tightened around the IABP catheter, with a silk suture. The incision is closed, with all the graft inside, and interrupted sutures. When the time comes to stop the LV assistance, the catheter is withdrawn, by surfacing the distal end of the saphenous graft and cutting the suture that tights the IABP catether. The catether is gently pulled out, the vein graft is ligated and its distal part cut away. The graft tends to retract back.

 

Table 1 - Underline pathology of those patients submitted to
cardiac surgery, who underwent IABP insertion

tabla1.gif (4217 bytes)

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Results: The overall survival was 46,9%, being 80% in the elective group. Mean pumping time was 54,5 hours for the survival group. The 53,1% mortality rate occurred in the ischemic heart disease group, in 52,9%. The main cause for insertion of the IABP was LV failure (Table2), in the three groups. In no case was the mortality due to the insertion technique, and the complication rate was 6,25%, due to severe peripheral vascular disease in two cases.

Table 2 - Causes for IABP insertion

tabla2.gif (2983 bytes)

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Discussion:  Recognised as a LV circulatory assist device, easy to handle and proved efficacy, the percentage of patients that use of IABP, has increased over the years, and the indications for insertion have broadened. Despite the fact that there is an agreement to indicate this type of aortic counterpulsation, only recently the results of an earlier insertion showed an increase in short and medium term survival. Also another topic of discussion is what type of insertion is best for the patient, quickest and with less vascular complications. The method presented in this paper, is another technique is the surgeons armamentarium. The strongest points for the use of the vein graft technique are: a) it does not do any harm to the patient, to leave a vein graft attached to an artery, as in an aortic-coronary occluded vein graft; b) its an easy technique for a surgeon, specially in the OR: c) by leaving the graft, when the catether is taken out, there is no damaged done to the artery. Also using this technique there is no need for a second surgery to withdraw the IABP catether, because it can be done at the bed-side in the intensive care, there is no need for the use of prosthetic material (such as Dacron, that has to be taken out) and it lowers the risk of infection, when compared with conventional cut-down techniques. If we look at the percutaneous technique of insertion, it seems that the vascular complications are very high, specially due to arterial aneurysms and bleeding complications, and there are some difficulties in inserting percoutaneously when a fair pulse can not be felt. There were no serious complications due to this new technique and balloon counterpulsation was only stopped in two patients due to their severe peripheral vascular disease in two cases. As from the results obtained in this report, we tend towards an earlier indication for IABP insertion and in same cases even a pre-operative insertion, so that a more viable myocardium can be obtained at the time of surgery.

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Conclusions: Despite the small group of patients presented, this technique is a good choice for patients in cardiogenic shock, when the femoral pulse is hard to feel, when the patient is in OR and specially because it avoids a new surgery for withdrawing the catether.

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References:

1. Clauss RM, Missier P, Reed GF, Tice D – Assisted circulation by counterpulsation with an intraaortic balloon: methods and affects. In: Digest. 15 th Annual Conference On Engineering in Medicine and Biology. Chicago: Northwestern University, 1962: 44.
2. Molopoulus SD. Topaz W, Kolpp WJ – Diastolic balloon pumping (with carbon dioxide) in the aorta: a mechanical assistance to failing circulation. Am Heart J 1962; 63: 669-75
3. Kantrowitz A, Akutsu T, Chaptal PPA, Krakauer J, James RT – A clinical experience with and implanted mechanical auxiliary ventricle. JAMA 1966; 197: 525-9.
4. Bregman D, Nichols AB, Weiss MB, Powers ER, Martin EC, Cassarella WJ – Percutaneous intraaortic balloon insertion. Am J Cardiol 1980; 46: 216-7.
5. Subramanian VA, Goldstein JE, Sos TA, McCabe JC, Hoover EA, Gay WA – Preliminary clinical experience with percutaneos intraaortic balloon pumping. Circulation 1980; 62 (Suppl 1):123-9.
6. Seldinger SI – Catheter replacement of the needle in percutaneous arteriography: a new technique. Acta Radiol (Stockholm) 1953; 39:368-70.

Questions, contributions and commentaries to the Authors: send an e-mail message (up to 15 lines, without attachments) to surgery-pcvc@pcvc.sminter.com.ar , written either in English, Spanish, or Portuguese.

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Update
Oct/30/1999