Review of 131 Consecutive Patients Gerald F. Geisler, M.D., Maurice Adam, M.D., Ben F. Mitchel, M.D., Cary J. Lambert, M.D., and J. Peter Thiele, M.D.

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1 Treatment of Severe Coronary Artery Disease with 5, 6, and 7 Saphenous Vein Bypasses: Review of 131 Consecutive Patients Gerald F. Geisler, M.D., Maurice Adam, M.D., Ben F. Mitchel, M.D., Cary J. Lambert, M.D., and J. Peter Thiele, M.D. ABSTRACT One hundred thirty-one consecutive patients who received 5, 6, and 7 bypass grafts are analyzed. Ages ranged from 31 to 74 years. The maleto-female ratio was 7 : 1. As an indication of severity of disease, 25% were classified as having impending myocardial infarction and 46.6% were classified in New York Heart Association Functional Class IV. Left ventricular function was impaired in 37.4'/0, and 30% of the patients had left main coronary obstruction. Nonfatal perioperative myocardial infarction occurred in 4.6%. The hospital mortality was 3%. One hundred percent follow-up (5 to 55 months) revealed 4 late deaths, 3 presumably of cardiac origin. Only 7 patients in the postoperative follow-up group have complained of angina; 1 has since undergone successful reoperation. Myocardial revascularization by direct bypass grafting for the treatment of coronary artery disease is the most rapidly evolving technique in the field of surgery today. Favaloro and Effler [3-51 reported clinical experience with saphenous vein interposition grafts and single saphenous vein bypass grafts primarily to the right coronary a.rtery. Johnson and Lepley [71 extended the use of reversed saphenous vein bypass grafts to the left coronary distribution. Since 1968, surgical teams throughout the country have progressed from single-graft revascularization to double- and triple-bypass procedures, which were common by 1970 [91. Ray and associates [lll have stressed the importance of the diagonal branches in performance of quadruple,-bypass procedures. Stoney and col- From the Departments of Thoracic and Cardiovascular Surgery, St. Paul Hospital and Baylor University Medical Center, Dallas, TX. Presented at the Twenty-third Annual Meeting of the Southern Thoracic Surgical Association, Nov 4-6,1976, Acapulco, Mexico. Address reprint requests to Dr. Geisler, 3434 Swiss Ave, Suite 404, Dallas, TX leagues U61 have suggested the possible value of revascularization of the first septa1 perforator. Harlan and co-workers 161 have recently reported their results with quadruple and quintuple saphenous vein bypass grafting. Complete revascularization of all ischemic myocardium is an important factor in decreasing operative risk [lo]. Since March, 1972, when we performed our first quintuple coronary bypass procedure, 131 consecutive patients with extremely extensive multiple-vessel coronary artery disease receiving 5 or more bypasses have been analyzed. This group of patients was drawn from a total of 2,351 patients who had coronary bypass operations. It represents 7.7% of all bypass procedures since our first quintuple bypass was performed. Of these 131 patients, 97 (74%) received 5 grafts; 29 (22%) received 6 grafts; and only 5 (4%) received 7 grafts. In the beginning of this series, separate veins were utilized for each bypass. From our experience and that reported by Bartley [21 and Sewell [13, 141, we have developed increasing confidence in the use of snake grafts, so that as many as 4 vessels might be bypassed with a single vein segment. This has been our more common practice in patients recently operated on. This report presents the rationale and technique for multiple bypass grafting and an analysis of the results. Clinical Material One hundred thirty-one consecutive patients with coronary artery disease have received 5,6, or 7 saphenous vein bypass grafts between March, 1972, and May, 1976, at the St. Paul Hospital and Baylor University Medical Center, Dallas. Ninety-seven patients (74 %) received 5 bypass grafts; 29 patients (22%) received 6 bypasses; and 5 patients (4%) had 7 bypass 246

2 247 Geisler et al: Five, Six, and Seven Bypasses grafts. Ages ranged from 31 to 74 years, with a mean age of The male-to-female ratio was 7: 1. All but 2 patients had classic angina pectoris. These 2 individuals underwent treadmill stress testing as evaluation for recent fatigue or malaise. They were found to have major electrocardiographic abnormality as well as severe correlative coronary angiographic disease. According to the New York Heart Association s (NYHA) Functional Classification for severity of anginal pain, 22 patients (16.8%) were in Class 11, 46 (35.1%) were in Class 111, and 61 (46.6%) were in Class IV. Thirty-three patients (25%) were classified as having impending myocardial infarctions; 3 of these were operated on in the course of acute myocardial infarction with impending extension of the infarction or the development of mitral insufficiency or left ventricular failure unresponsive to conventional medical means. Fifty-five patients (42%) had history or findings of prior myocardial infarction. All patients underwent diagnostic coronary angiography preoperatively, and all but 2 had left ventriculographic studies. Ventriculograms were omitted in these 2 patients because of their critical clinical condition at the time of study. Of 694 arteries bypassed, 20% showed total occlusion, 47% showed 90 to 99% stenosis, 23% showed 75 to 89% obstruction, and 10% showed 50 to 74% encroachment on the lumen. Forty patients (30%) had greater than 50% obstruction of the left main coronary artery in addition to severe major branch disease. Ventricular function was evaluated by right anterior oblique ventriculograms, and overall performance was graded as good, fair, or poor. Good ventricular function (ejection fraction more than 55% and no dyskinesia or hypokinesia) was present in 62.6% of the patients. Fair ventricular function (ejection fraction from 30 to 55% and one area of dyskinesia, hypokinesia, or akinesia) was present in 26%. Poor ventricular function (ejection fraction less than 30%, left ventricular end-diastolic pressure greater than 15 mm Hg, and two or more areas of dyskinesia, hypokinesia, or akinesia) was present in 11.4%. The left coronary artery received 542 bypasses (Fig 1). The left anterior descending coronary Posterior Descending (92) Groove Continuatim or Left Ventricular Branch (36) Fig 1. Distribution of bypass sites in right coronary artery (252 patients). artery (LAD) was bypassed in all patients. (Ten patients received 2 bypasses to the LAD. Three of these bypasses were directed to large isolated first septa1 perforators.) The diagonal received 132 bypasses. (Two diagonal branches were bypassed in 17 patients.) The circumflex system received 221 bypasses. Circumflex marginal branches received 182 bypasses, and posterior ventricular branches of the circumflex or posterior descending branches of a dominant left coronary system received 39 bypass grafts. The intermediate coronary received 48 bypasses. The right coronary artery received 152 bypasses (Fig 2); 24 were placed in the distal main right coronary, 92 into the posterior descending branch, and 36 into the groove continuation or a large left ventricular branch. Five patients required concomitant carotid endarterectomy because of coexisting symptomatic cerebrovascular insufficiency at the time of operation. Three patients required permanent pacemakers: 1, an aortic valve replacement; and 1, resection of left ventricular aneurysm. An intraaortic balloon was utilized as a cardiac assist device in 9 patients preoperatively recognized to be unusually high risks. Operative Technique Standard operative techniques were followed. A bubble oxygenator was used to maintain a high

3 248 The Annals of Thoracic Surgery Vol 24 No 3 September 1977 Ramus Medialis or Intermediate Coronary (48) Marghal Circumflex Posterior Ventricular or Posterior Descending (39) (2 diagonal bmsses in 17) ( 2 bypasses in 10 1 Fig 2. Distribution of bypass sites in left coronary artery (542 patients). flow of 2.4 liters per square meter of body surface area per minute. Mild systemic hypothermia (32" to 34 C) was used. Myocardial protection was obtained by topical hypothermia with saline slush and infusion of chilled saline through the vein bypass at the completion of distal anastomoses. Only one period of aortic occlusion was used during performance of the distal anastomoses. An effort was made to avoid total ischemia in excess of 50 minutes. The saphenous vein was used for grafting in all patients. The distal anastomoses were usually performed with interrupted 6-0 silk suture technique, although running 6-0 Prolene sutures were used in a few cases. The proximal anastomoses were made with running 5-0 Prolene sutures to the ascending aorta with a tangential partially occluding clamp. Slight magnification by corrective lenses or loupes at X1.5 to X2.5 was used in most instances to ensure maximum accuracy in the performance of the anastomoses. Initially there was a strong bias toward the use of separate veins for each distal anastomosis. Because of the convenience with which a diagonal anastomosis could be performed in a side-to-side fashion with a vein graft to the LAD, we developed increasing confidence in this technique. Reports of others [13, 141 substantiate favorable long-term follow-up with multiple anastomoses along one segment of a large-caliber vein; thus this technique has recently been used with greater frequency. Five, 6, and 7 distal anastomoses are now accomplished regularly with two and rarely more than three segments of vein. The LAD, second and first diagonal, and intermediate coronary arteries can often be bypassed easily with one segment of vein. Vessels on the inferior and lateral wall may require more than one vein in order to avoid distortion of the conduit, particularly at the site of side-to-side anastomoses with adjacent vessels pursuing a parallel course. Usually careful selection of the anastomotic site will avoid this. Most of our procedures were performed with parallel anastomoses between coronaries and saphenous veins. An alternative would be the use of perpendicular anastomoses [2, 151. Coronary endarterectomy has been carefully avoided, although it was necessary in several patients to complete a satisfactory anastomosis. An intimate knowledge of the coronary angiogram is prerequisite to accurate recognition of the optimum bypass site for the appropriate vessels. Results Mortality There were no intraoperative deaths. Four patients died while still in the hospital. The first was a 47-year-old diabetic with emphysema who suffered a cerebrovascular accident on the seventh postoperative day, before which his

4 249 Geisler et al: Five, Six, and Seven Bypasses convalescence had been normal. Extension of the infarction resulted in death on the tenth postoperative day. The second death was that of a 73-year-old man who was hospitalized with an acute myocardial infarction. He developed extensior, of the infarct and acute mitral insufficiency. An intraaortic balloon was inserted and a quintuple coronary bypass procedure was performed. The balloon was removed on the second postoperative day when the patient was convalescing well. He developed acute abdomen on the fifth postoperative day and underwent a laparotomy, at which time 3 m of ischemic small bowel containing diffuse jejunal and ileal diverticuli as well as a Meckel s diverticulum was removed. He recovered from this but developed an acute febrile illness 20 days following his cardiac procedure. Cephalothin and gentamicin were administered, and within 6 days he was totally anuric. He was placed on hemodialysis for 3 weeks, but there was no recovery of renal function. He died in the hospital 49 days postoperatively. The third death was that of a 65-year-old man who was apparently convalescing well but developed innominate and left subclavian venous thrombosis on the fifth postoperative day. In spite of heparinization, the condition critically progressed to phlegmasia alba dolens, which required venous thrombectomy and fasciotomy. This patient developed a severe disseminated intravascular coagulopathy and died on the tenth postoperative day. The fourth patient was a 65-year-old man who had undergone a quintuple coronary bypass procedure. Following his bypass, he developed a cerebrovascular accident which extended clinically on several occasions and ultimately culminated in death 98 days postoperatively while he was still hospitalized. The fifth death occurred in a 49-year-old man who had undergone 6 coronary bypasses. He enjoyed a smooth postoperative course, was discharged from the hospital on the seventh postoperative day, and returned 2 weeks later with an acute massive intracerebral hemorrhage which caused his death 25 days postoperatively. Morbidity Nonfatal perioperative myocardial infarctions, indicated by new or deeper Q waves and eleva- tion of serum glutamic oxaloacetic transaminase above 150 units, occurred in the first postoperative day in 6 patients. (Three infarcts occurred in the first 7 patients of the series.) Of these patients, none sustained low cardiac output. Only 1 patient in this group required longer hospitalization. Other nonfatal complications included transient neurological problems in 2 patients. Postoperative bleeding requiring reoperation occurred in 2 patients. Mediastinitis occurred in 1 patient, who returned after a normal convalescence following discharge 21 days postoperatively. This was treated by drainage with total recovery. Comment To achieve optimum revascularization, every coronary branch with proximal stenosis should receive a bypass graft if technically feasible. We believe that 75% stenosis is critical, but we are willing to bypass vessels with as little as 50 /o stenosis at the time of revascularization. We think that vessels with an internal diameter smaller than 1.5 mm should be avoided unless this represents the general size of the entire recipient coronary tree. The usual indications for fourth or fifth bypass have been outlined well [6, 111. Rationale for performance of 5, 6, or 7 bypasses may be extended to patients with a rich supply of limbs on their coronary tree. These individuals have a more abundant development of coronary branches than is normally seen. With concomitantly extensive coronary obstructive disease in these patients, one might expect to leave areas of ischemic myocardium if all involved branches are not treated with appropriate bypass. Anatomical consideration is given to appropriate sites for bypass grafts. The left coronary artery system would include the LAD, the first and second diagonal branches, and the first septal perforator. Variations in the circumflex coronary artery would offer first, second, and possibly third and fourth circumflex marginal branches, the posterior ventricular branch, or (one might say) in the case of a dominant left coronary system, the posterior descending branch. The ramus mediales or intermediate coronarv,

5 250 The Annals of Thoracic Surgery Vol 24 No 3 September 1977 artery arising between the LAD and circumflex is an inconstant but frequently large and important branch. The right coronary system should include the distal main coronary, the posterior descending branch, and the groove continuation or large terminal left ventricular branches. The acute marginal branch of the right coronary artery is not considered of major clinical importance, except in rare occasions when it takes a somewhat deviant course to supply the inferior and distal half of the ventricular septum, in which case the proximal inferior portion of the septum is supplied by the posterior descending branch. Familiarity with the patient s coronary cineangiograms is mandatory because it is not uncommon to encounter totally occluded vessels of adequate caliber supplying viable muscle that were not demonstrated at the time of angiography, but that can be seen when the surface of the heart is inspected during operation. In contrast, it is not uncommon that vessels to be bypassed are obscured due to pericarditis, previous adhesions, a heavy layer of epicardial fat, or intramyocardial position of the vessel. A thorough knowledge of the preoperative angiographic study will help reveal the location of these vessels. At operation additional information may be gained regarding the gross size and quality of a potential coronary vessel to be bypassed as well as the nature of the myocardium it supplies. Vessels supplying old areas of infarction are bypassed when it is determined at operation that scar tissue is mixed with viable, and possibly functional, myocardium. A vessel supplying an area of ventricular aneurysm is not likely to be bypassed; rather, the aneurysm would be resected or plicated. To further justify bypass into areas of old infarction, we have witnessed improvement of myocardial contractility following completion of bypass grafting into the involved area. This is further corroborated by the not infrequently large flows measured through an electromagnetic flowmeter placed about the bypass graft at the time of operation. The importance of flow readings remains somewhat unsettled; although it would seem logical to expect viable, functioning myocardium to accept a higher flow than noncontractile scar tissue. Two patients in this series did not have angina in the classic sense. Their physicians were alerted by symptoms of fatigue or malaise. Maximal treadmill stress tests uncovered electrocardiographic evidence of serious myocardial ischemia. Coronary angiography corroborated this with demonstration of what is recognized as severe coronary arterial occlusive disease. We concur with others [12] that coronary bypass should be extended to carefully selected patients who have no symptoms of angina but whose findings include a strongly positive stress test supported with correlated angiographic findings of high-grade stenosis of 1 or more major coronary arteries (especially the left main coronary and the LAD above the level of the first diagonal branch). The low mortality in this series makes it statistically difficult to cite specific factors previously thought to increase the operative risks of coronary artery bypass operation. This group comprised 43.5% patients over 60 years of age; 14.3% were women; 81.7% were in NYHA Class III or IV; and 25% were classified as having impending myocardial infarction [l, 81. Left main coronary stenosis (>50%) was present in 30%. Left ventricular function was impaired in 37.4%, and 11.4% had generalized hypokinesia [lo]. Five patients required concomitant carotid endarterectomy, 1 required aortic valve replacement, and 1 required resection of left ventricular aneurysm. The intraaortic balloon cardiac assist device was utilized in 9 patients considered preoperatively to be unusually high operative risks. The indications for its use were: operation being required in the course of an acute myocardial infarction with impending extension, mitral insufficiency, ventricular failure, or extremely poor ventricular function. It was also used successfully for impending myocardial infarction and medically uncontrollable ischemic arrhythmia and in 1 patient who had concomitant aorticvalve replacement with quintuple coronary bypass. We believe that long-term follow-up will be of tremendous importance in this group of patients, many of whom might have been rejected for operation on the basis of extensiveness of coronary artery occlusive disease. The inhospital mortality of 3% reflects the severity of the disease and compares favorably with other

6 251 Geisler et al: Five, Six, and Seven Bypasses recently reported operative mortalities for quadruple and quintuple bypass procedures [9,161. Addendum Since this paper was presented for publication, long-term follow-up has been obtained in 100% of the patients and ranges from 5 to 55 months. There have been 4 late deaths between 8 and 27 months postoperatively. Three of these deaths are thought to be due to myocardial infarction although this was not confirmed by postmortem examination. The fourth death was due to complications following operation for acute mesenteric artery obstruction. Only 7 patients in the postoperative follow-up group have complained of angina; 1 has since been successfully reoperated. References 1. Adam M, MitchelBF, Geisler GF, et al: Surgery for Impending Myocardial Infarction. Edited by WR Webb. Medcom, 1975, p Bartley TD, Bigelow JC, Page US: Aortocoronary bypass grafting with multiple sequential anastomoses to a single vein. Arch Surg 105:915, Effler DB, Favaloro RG, Groves LK: Coronary artery surgery utilizing saphenous vein graft techniques. J Thorac Cardiovasc Surg 59:147, Favaloro RG: Saphenous vein autograft replacement of severe segmental coronary artery occlusion: operative technique. Ann Thorac Surg 5:334, Favaloro RG: Saphenous vein graft in the surgical treatment of coronary artery disease. J Thorac Cardiovasc Surg 58:178, Harlan BJ, Reul GJ, Cooley DA, et al: Treatment of severe coronary artery disease with quadruple and quintuple saphenous vein grafts. Chest 69:29, Johnson WD, Lepley D: An aggressive surgical approach to coronary disease. J Thorac Cardiovasc Surg 59:128, Lambert CJ, Adam M, Geisler GF, et al: Emergency myocardial revascularization for impending infarctions and arrhythmias. J Thorac Cardiovasc Surg 62:522, Mitchel BF, Adam M, Lambert CJ, et al: Ascending aorta-to-coronary artery saphenous vein bypass grafts. J Thorac Cardiovasc Surg 60:457, Mitchel BF, Alivizatos PA, Adam M, et al: Myocardial revascularization in patients with poor ventricular function. J Thorac Cardiovasc Surg 69:52, Ray JF 111, Myers WO, Wenzel FJ, et al: Quadruple coronary artery bypass grafting. Ann Thorac Surg 21:7, Reul GJ, Cooley DA, Sandiford FM, et al: Aortocoronary artery bypass: present indications and risk factors. Arch Surg 111:414, Sewell WH: Improved coronary vein graft patency rates with side-to-side anastomoses. Ann Thorac Surg 17:538, Sewell WH, Sewell KV: Technique for the coronary snake graft operation. Ann Thorac Surg 22:58, Stiles QR, Tucker BL, Lindesmith GG, et al: Myocardial Revascularization: A Surgical Atlas. Boston, Little, Brown, 1974, p Stoney WS, Vernon RP, Alford WC, et al: Revascularization of the septa1 artery. Ann Thorac Surg 21:2, 1976