Saphenous Vein Bypass Grafting for Coronary Atherosclerosis: Clinical Experience
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MEDICAL PRACTICE Saphenous vein bypass grafting for coronary atherosclerosis: clinical experience. A. S. Trimble, m.d., L. L. Black, m.d. and H. E. Aldridge, m.d., Toronto Summary: Saphenous vein bypass Direct myocardial revascularization meticulous to allow perfect intima- grafting is a recent and important for coronary atherosclerosis using to-intima approximation. Great care procedure in the management of reversed saphenous veins grafted to must also be taken in the determina¬ atherosclerotic coronary artery the distal coronary arterial tree has tion of the length of the graft prior disease. A review of the first 150 been popularized by surgical groups to its anastomosis to the aorta. patients operated on to July 1971 at in Milwaukee and Cleveland.14 the Toronto General Hospital is This procedure has been accepted Bypass graft experience presented. Many had multiple bypass with unprecedented enthusiasm by The combined experience of all car¬ grafts and some had additional many cardiovascular centres. Each diac surgeons at the Toronto Gen¬ procedures including internal week, around the world, the opera¬ eral Hospital to July 1, 1971 includes mammary artery implantation, valve tion is being performed on literally 150 patients. The ages range from replacement and scar tissue hundreds of patients. 26 to 65 years with a mean of 49 resection. There were five operative At the Toronto General Hospital years. One hundred and forty pa¬ deaths (3%) and an additional we have accumulated experience with tients were men and 10 were women. five hospital deaths; the majority 232 patients over the past three All patients were experiencing an¬ were related to myocardial years. Although we entered the field gina. Ninety-eight had had previous infarction. cautiously the early excellent results evidence of myocardial infarction A clinical review of the results six have so impressed surgeons and and 38 of these had had at least two months to three years after operation cardiologists that the number of pa¬ infarctions. Congestive failure was indicates marked improvement in tients being operated on is rapidly being managed medically in 17 pa¬ over 80% of the survivors. increasing (Fig. 1). This report re¬ tients. Postoperative hemodynamic studies views our experience with the first Ten patients had systemic hyper¬ were performed in many. It is 150 patients operated on up to July tension (greater than 140/90 mm. suggested that patients with poor 1, 1971. It offers therefore a six- Hg). Ten had peripheral vascular myocardial function presenting in month to three-year clinical follow- occlusive disease in the lower extrem¬ failure may not benefit from the up. ities. Over two thirds of the patients operation. smoked one or more packages of Operative technique cigarettes a day, many for 20 years. From the Cardiovascular Unit and the The technique for operation has be¬ A similar number gave a family his¬ Division of Cardiovascular Surgery, Toronto come standardized and only a brief tory indicative of coronary disease. General Hospital, Toronto, Ontario. comment is in order. It should in¬ Most patients were receiving a va¬ Supported by the Ontario Heart Foundation. clude total cardiopulmonary bypass riety of medications including digox¬ Reprint requests to: Dr. A. S. Trimble, with adjuncts of normo- or hypo¬ in, diuretics, nitroglycerin or isosor- Cardiovascular Unit, Toronto General thermic anoxic cardiac elec- bide dinitrate and A 101 arrest, propranolol. Hospital, College Street, total of 218 were Toronto 2, Ontario. trical fibrillation and venting in grafts performed in order to provide a perfectly still, dry the 150 patients (Fig. 2). Additional field for performing the anastomo- combined procedures included in¬ ses. Suturing must be carried out ternal mammary implantation in 16, under magnification and must be resection of scar tissue in four and C.M.A. JOURNAL/OCTOBER 7, 1972/VOL. 107 649 aortic valve replacement in five. groups. In Group A there were 115 Discussion patients for follow-up. Of these, 97 Like many others1'7 we have been Results (84%) were considered to be clinical¬ impressed by the early results of my¬ There were five operative deaths ly markedly improved. The majority ocardial revascularization using the (3%) and five additional hospital had no angina whatsoever; 16 pa¬ saphenous vein bypass technique. deaths (3%). Four ofthe five patients tients (14%) were unimproved and From the beginning we were con¬ who died at operation showed evi¬ there were two late deaths from myo¬ cerned about the generalizations that dence of recent infarction and could cardial infarction. In Group B eight all patients with coronary atheroscle¬ not sustain a blood pressure when of the 10 survivors (80%) could be rosis were candidates for this proce¬ taken off the heart-lung machine. All initially considered improved. How¬ dure, that all vessels were graftable grafts in these patients were patent. ever improvement was not nearly as and that all patients could be mark¬ Four of the five hospital deaths were dramatic as in the Group A patients edly benefited. also due to recent myocardial in¬ and tended to occur early in the post¬ This review suggests that patients farction, confirmed at autopsy. In operative course. Within six months with extensive myocardial dysfunc¬ three of these thrombosis of the graft only four of the 10 survivors could tion are unacceptable for surgery had led to infarction of ventricular still be considered improved. Seven because of a high operative mortali¬ muscle in the area of distribution of of the 10 patients were on anti-fail¬ ty and usually unimpressive im¬ the grafted coronary artery. In the ure therapy and the majority of them provement in their symptomatology. fifth patient thrombophlebitis at the had not returned to work. One pa¬ The majority of such patients pre¬ graft donor site led to recurrent and tient was not improved and there sented with congestive failure and finally fatal pulmonary embolism. was one late death due to myocardial angina was only a minor component Early or late myocardial infarction infarction. of their disability. It seems illogical was diagnosed in 14 patients, 11 oc¬ to expect any form of revasculariza¬ curring in hospital. The other three tion to improve myocardial func¬ patients who developed late infarc¬ Preinfarction angina tion if extensive fibrosis of the myo¬ tion had had graft patency demon¬ Many centres are reporting success¬ cardium has occurred. However, strated to One of ful bypass surgery in patients with there be some It is prior discharge. From this may exceptions. these was "preinfarction angina". difficult to distinguish by ventri¬ patients re-investigated series we have to and found to have thrombosis of been able select 18 a fibrosed myo¬ who fit into this cate¬ culography diffusely both grafts. patients may cardium from one that is hypoper- A classical postpericardiotomy gory. fused. Only in isolated circumstances syndrome developed in 22 patients. In 13 the angina was of a crescen- should patients with Grade IV ven- Thrombophlebitis at the donor do type with pain of increased fre¬ site of the graft occurred in 14 pa¬ quency but short duration, always tients, with subsequent pulmonary relieved by nitroglycerin. The pain TORONTO GENERAL HOSPITAL embolism in six. In one patient this often occurred at rest and in the ma¬ CORONARY BYPASS GRAFTS (232 PATIENTS) was massive and fatal (see above). jority, nitroglycerin consumption An attempt was made to correlate had increased from a few tablets mortality, complications and late daily to as many as 100 per day. In improvement with the preoperative this group there were no hospital or clinical findings and catheterization late deaths. Twelve (95%) were mark¬ data. The cineangiographic grading edly improved with total relief from of left ventricular function, using the their angina. classification of Lansdown, Aldridge The other five patients differed and in that to ex¬ Spratt,5 permitted meaningful clinically they began FIG. 1.The marked increase in number of of an¬ prognostic separation patients perience prolonged episodes of bypass operations at the Toronto General with Grades I to III from those with gina and obtained little relief with Hospital over the past three years. Grade IV function. (This is an an¬ nitroglycerin. Often meperidine was giographic classification of ventricu¬ required to relieve the pain, which lar and is not also occurred at rest but in a mark¬ contractility equivalent 150 PATIENTS to the clinical grading of the New edly different pattern. In this group York Heart Association functional there were two hospital deaths and classification.) one late death due to myocardial in¬ 218 VEIN BYPASS GRAFTS Table I sets forth data on hospital farction. The two surviving patients mortality and complications such as have remained unimproved; one has myocardial infarction, arrhythmia had at least two myocardial infarcts and congestive failure in the two during the follow-up period. Table I FIG. 2.The coronary vessels grafted. 650 C.M.A. JOURNAL/OCTOBER 7, 1972/VOL. 107 tricular function be accepted for sur- there has been a return to internal coronaire: experience clinique gery and then only if all areas affect- mammary implantations and now a ed can be revascularized. number of combined procedures are La greffe de veine saphene pour pon- Patient volume has prohibited us being carried out. Statistics dating tage est une recente operation, im- from assessing all grafts in the early back to 1953 on the use of the in- portante pour le traitement de la postoperative period by repeat an- ternal mammary implant show that maladie atherosclerotique des arte- giography. Of 47 patients who had in 60 to 65% of patients, filling of res coronaires. Les auteurs passent excellent clinical results within six the coronary arterial tree from the en revue les 150 premiers malades months of operation, all had at least implant can be demonstrated.