Bypass of the right and circumflex coronary arteries with the internal mammary artery.

Our experience with the internal mammary artery (IMA) for coronary bypass grafting in the past 3 years includes 323 grafts in 253 patients. After an initial group of IMA to left anterior descending (LAD) coronary artery grafts, we began using the IMA to bypass circumflex and small right coronary arteries (RCA). This report describes our experience with IMA bypass of coronary vessels other than the LAD. A total of 96 patients have had an IMA graft to the circumflex or RCA. Most of these patients had two or more bypasses. The mortality rate for this group has been 7 per cent, 7 of 96 patients. Postoperative angiography in 82 of 89 survivors has shown a patency rate of 98 per cent in 83 of 85 grafts studied. We conclude that the IMA is the vessel of choice for coronary artery bypass and that it can be used to bypass any of the main coronary arteries.     

Effects of coronary bypass surgery on the electrical activity of revascularized myocardium. Immediate and early postoperativeobservations.

The effect of myocardial revascularization on bipolar epicardial electrograms was recorded with fixed wire electrodes from revascularized left ventricular sites and from control sites on the right ventricle. Studies were performed during and after surgery in 19 patients undergoing aorta-coronary bypass grafting for occlusive coronary artery disease and in 6 additional patients having aortic valve replacement for isolated aortic valve disease. In the latter 6 patients, neither left nor right ventricular electrogram voltage changed immediately following aortic valve replacement; however, left ventricular electrogram voltage gradually decreased for 5 days postoperatively. In the 19 patients with coronary artery disease, electrogram voltage in the revascularized area increased immediately following coronary bypass grafting (+40 to +300 per cent) in 13 patients (68 per cent) and immediately decreased (-20 to -70 per cent) in 6 patients (32 per cent). In 5 of the patients showing immediate increases, temporary occlusion of the bypass grafts for 3 minutes during surgery resulted in a decrease of electrogram voltage in the distribution of the occluded bypass, followed by return to preocclusion levels after release. Postoperative monitoring of electrogram voltage for 5 days in all patients with coronary artery disease revealed that the electrogram voltage in the revascularized area decreased to or below control levels in 16 patients (84 per cent) and remained increased in 3 patients (16 per cent). These observed changes did not correlate with preoperative hemodynamics, number of grafts, graft flow rate, aortic cross-clamp time, cardiopulmonary bypass time, and the early postoperative course. These preliminary observations suggest that coronary bypass grafting does affect the electrophysiological state of the revascularized myocardium. However, the mechanism by which it occurs and its clinical implications remain to be determined.     

Operative flow measurements and coronary bypass graft patency.

Early (one week) and late (one year) postoperative angiography was performed in 142 patients having 310 grafts (117 right coronary artery [RCA], 134 left anterior descending [LAD], and 59 circumflex coronary artery [CCA]) to assess the factors responsible for failure of aorta-coronary artery saphenous vein grafts. Early catheterization revealed an 85.5 per cent patency rate with similar rates for each artery (RCA 88 per cent, LAD 85 per cent, and CCA 81 per cent). At one year 238 grafts remained patent, for a cumulative patency rate of 76.8 per cent with a similar distribution for each vessel (RCA 75 per cent, LAD 78 per cent, and CCA 76 per cent). Intraoperative flow measurements were correlated with early and late patency. Grafts with a basal flow less than 20 ml. per minute have a 42 per cent early closure rate and a 21 per cent late closure rate (cumulative 63 per cent). A basal flow of less than 40 ml. per minute was associated with a 25 per cent early failure and an 11 per cent late failure rate (cumulative 36 per cent). Basal flow at levels greater than 40 ml. per minute was not associated with an increased probability of graft closure. Absence of reactive hyperemia (30 second graft occlusion) was associated with a 19 per cent probability of early closure and a 31 per cent probability of cumulative thrombosis. A papaverine-induced flow increase (15 mg. given into the graft) of less than 100 per cent over basal flow gave a 20 per cent probability of early failure and 30 per cent probability of cumulative closure. Thus intraoperative basal flow measurements are of predictive value in determining the fate of aorta-coronary artery vein bypass grafts, and vasodilatory maneuvers provide little additional information.     

Intraoperative flow measurements in gastroepiploic grafts using pulsed Doppler.

OBJECTIVE: The patency of a pedicled right gastroepiploic artery (RGEA) graft can be compromised by intraoperative twists, kinks or spasms. Therefore, a systematic flow assessment was made in RGEA grafts and was compared with similar measurements made in other types of bypass conduits. METHODS: Intraoperative pulsed Doppler flowmeter measurements obtained in a series of 556 consecutive patients undergoing at least one coronary bypass grafting onto the right coronary system were studied. Eighty-five RGEA grafts were compared with 1427 bypass grafts implanted in the same group of patients and consisted of the following conduits: 442 left internal mammary (LIMA), 149 right internal mammary (RIMA), 831 greater saphenous vein (GSV) and five inferior epigastric (EPIG) grafts. Sequential grafts were excluded from the analysis. RESULTS: Flow measurements and Doppler waveforms were abnormal and required graft repositioning, and the addition of a distal graft or intragraft papaverine injection (only in GSVs) in 29 cases (2.0% of all grafts). These graft corrections were necessary in 5.9% RGEAs, 3.4% LIMAs, 2.0% RIMAs, and 0.7% GSVs (P < 0.001). The relative risk for graft correction was eight times higher for RGEAs than for GSVs (P = 0.002). Flow increased from 8 +/- 2 to 54 +/- 5 ml/min (P < 0.0001). Flow data were significantly influenced by the type of run-off bed (P < 0.001), the measurements obtained in grafts implanted onto the right coronary artery and the left anterior descending artery being superior. Flows in RGEAs, however, were comparable with values obtained in other grafts implanted onto the same recipient coronary artery. CONCLUSIONS: A significantly higher incidence of graft malpositioning caused inadequate flows in RGEAs. However, normal flow values could be restored simply by assigning a better graft orientation under pulsed Doppler flowmeter control. Overall flow capacity of the RGEA did not differ from values obtained in other arterial and venous grafts implanted onto the same recipient arteries.     

Use of the internal mammary artery as a free graft with reimplantation of the proximal end onto the ascending aorta. Apropos of 39 cases]

From January 1987 to January 1991, 104 patients received bilateral internal mammary artery grafts and 39 of them had coronary bypass with a free graft implanted on the ascending aorta. There were 35 men, with a mean age of 57.35 years (range 41 to 70 years). 87% of them had stable angina, and 23 had preoperative myocardial infarction. The left ventricular function was good in 77 per cent of cases. 23 patients had three vessel disease (61.5%), 13 two vessel diseases (30.7%), 2 one vessel disease (5.12%) and one a left main coronary stenosis. Left internal mammary artery was used in two patients on the left descending artery and the right internal mammary artery was used in 37 patients: 15 on the circumflex, 15 on the right coronary, 4 on the LDA and 3 on the diagonal artery. Five patients had one graft, 32 two grafts and one three grafts (bilateral mammary and saphenous vein). Hospital mortality was 2.56% (1 patient) and there were 2 late deaths (5.12%). There were 5 perioperative myocardial infractions (12.8%) and no sternal infections. The mean follow up is 21 months (range 3 to 46 months). At follow-up, 34 patients (87.2%) were asymptomatic, and there were no myocardial infarctions. Postoperative angiography in 8 patients (mean postoperative time 2.5 months) showed that all the grafts were patent. This analysis demonstrates that free IMA graft has a low operative risk and provides excellent long term functional improvement and survival.     

Graft patency in coronary bypass surgery.

A total of 514 vein bypass grafts and 49 internal mammary (IMA) grafts in 328 patients were studied after operation. Forty-two vein bypass grafts were performed without the use of a pump oxygenator, with a patency rate of 52%. When a pump oxygenator was used, the patency rate for vein bypass grafts was 78%. Patency rates for IMA grafts were 70% and 86%, respectively. In a small group of patients, endarterectomy with vein bypass grafts resulted in a patency rate of 59% in the right coronary artery, 88% in the left anterior descending coronary artery, and 74% in the circumflex artery. Except for the right coronary artery, these results compare favorably with those from vein bypass graft patency without endarterectomy. On the basis of these findings, insertion of bypass grafts into the coronary arteries without the use of a pump oxygenator cannot be recommended, unless the technique employed can be shown to produce graft patency rates comparable to those resulting from grafts done with the use of a pump oxygenator. Endarterectomy to the left anterior descending and circumflex arteries would not appear to affect vein bypass graft patency.     

In situ right gastroepiploic artery. A conduit for coronary revascularization

The internal mammary artery is widely recognized as the graft of choice for coronary artery bypass grafting at present. Alternative conduits have been investigated in order to find other adequate long-term grafts. The right gastroepiploic artery has been recently used as a graft to bypass distal coronary vessels. From November 1989 to June 1990, we have implanted this artery in 46 cases. Pedicled grafts were implanted in 20 patients to the main right coronary artery, in 21 patients we grafted the right distal branches, in 3 patients the left anterior descending, and in 2 the circumflex branches. Mean grafts per patient were 3 in this series, with a mean of 2.2 arterial grafts per patient. One patient died in the early postoperative period. The remaining patients had an uncomplicated postoperative evolution. Thirteen patients underwent graft and coronary angiography. Direct or indirect graft patency was confirmed in all cases. The final important issue concerning the long-term patency of this graft will be solved in the future, but short-term patency rates of the right gastroepiploic artery can be anticipated when proper techniques are used.     

Reoperations for myocardial revascularization.

Reoperations solely for myocardial revascularization were performed in 219 consecutive patients (1967 to 1975). Indications were (1) graft failure, 46 (21 per cent); (2) progressive atherosclerosis, 42 (19 per cent); (3) incomplete revascularization, 39 (18 per cent); and (4) combinations, 92 (42 per cent). Primary operations included bypass grafts in 100 patients; mammary artery implants, 87; and combinations of direct and indirect procedures, 32. Reoperations performed were single bypass, 141 patients; double, 61; and triple or other coronary artery operations, 17. Eight patients died within 30 days of operation (3.7 per cent). Major postoperative complications included hepatitis, 24 (11 per cent); myocardial infarction, 19 (9 per cent); bleeding, 21 (10 per cent); and respiratory insufficiency, 12 (5 per cent). Follow-up for 202 long-term survivors was complete (mean 29 months). In patients who originally underwent direct revascularization, Class I or II (N.Y.H.A.) was attained in 35 of 43 (81 per cent) of those reoperated upon for primary graft failure, in 14 of 15 (93 per cent) of those with progressive atherosclerosis, and in 27 of 33 (82 per cent) of patients with combined indications. Arteriography was performed after the reoperation in 55 patients (mean interval 17 months), and 65 of 77 (84 per cent) grafts were patent. Nineteen of 22 grafts performed for primary graft failure were patent. We have made the following conclusions: (1) Reoperation for direct myocardial revascularization can be accomplished with low mortality rates although morbidity is high; (2) complete relief of symptoms was achieved in 65 per cent of survivors; (3) results in patients reoperated upon for graft failure alone were similar to results in those operated upon for progressive atherosclerosis or combined indications; and (4) high graft patency was found in secondary grafts constructed to arteries involved with primary graft failure.     

Collateral blood flow between left coronary artery bypass grafts and chronically occluded right coronary circulation in patients with triple vessel disease. Observations during complete revascularisation of beating hearts.

OBJECTIVE: Preoperative measurements of collateral blood flow in patients with triple vessel disease and chronic occlusions of the right coronary artery do not, currently, ascertain the need to revascularise an occluded right coronary artery. We performed direct measurements of flow across left coronary bypass grafts to determine their contributions to collateral blood flow. METHODS: Collateral blood flow was scored preoperatively according to Rentrop in 13 patients with triple vessel disease and chronic occlusions of the right coronary artery who underwent complete, off-pump, surgical revascularisation. The transit-time flow through the left coronary grafts was measured before and after unclamping of the right coronary artery bypass graft. RESULTS: Unclamping of the right coronary artery bypass graft was associated with a 5.9+/-6.9ml/min (mean+/-SD) decrease in flow across the left circumflex territory (P=0.009), which was proportional to the preoperative Rentrop score (P=0.007). No significant change was observed in flow across the graft to the left anterior descending artery. CONCLUSIONS: Grafts to the left circumflex system are the only grafts that supply a significant, albeit modest amount of collateral blood flow to chronically occluded right coronary artery. These observations confirm that (1) most collateral flow after revascularisation is supplied by the native network, and (2) revascularisation of an occluded right coronary artery is fully justified.     

Clinical and angiographic assessment of complex mammary artery bypass grafting

The internal mammary artery has become the coronary bypass graft of choice in recent years because of enhanced long-term patency. Along with this trend, sequential, bilateral, and free mammary grafts have been employed more frequently in an effort to maximize the number of distal internal mammary anastomoses. This approach of maximally using the internal mammary artery (complex mammary grafting) seems logical, but at present little information about patency of the newer types of internal mammary artery grafts is available to justify the more complicated procedures. Over a 15 month period, 207 patients underwent bypass graft angiography from 1 to 32 weeks after operation. This is an 85% restudy rate for a consecutive series of coronary bypass procedures. Patency was defined as complete filling of the graft and distal vessel bypassed. A total of 841 distal vessels were grafted, or 4.1 per patient. The overall patency rate was 91% for 503 distal vein graft anastomoses and 99% for 338 internal mammary artery grafts. Individual patency rates of distal anastomoses, expressed as number patent/total (percent patent), were as follows: simple vein grafts, 262/285 (92%); sequential vein grafts, 196/218 (90%); left internal mammary artery to left anterior descending coronary artery, 109/110 (99%); left internal mammary to circumflex marginal artery, 14/14 (100%); right internal mammary to right coronary artery, 19/20 (95%); right internal mammary to left anterior descending coronary artery, 10/10 (100%); right internal mammary to circumflex marginal artery via transverse sinus, 18/20 (90%); sequential left internal mammary artery to left anterior descending system, 133/134 (99%); sequential left internal mammary to circumflex marginal system, 15/15 (100%); free internal mammary artery, 9/9 (100%); free sequential internal mammary artery, 6/6 (100%). Of the 18 patent transverse sinus right internal mammary grafts to the circumflex marginal artery, three exhibited very slow flow and probably were not functional. The hospital mortality associated with internal mammary revascularizations was 0.4% for nonemergency cases and 3.1% for emergency procedures. On the basis of clinical and postoperative graft patency data, expanded use of more complicated types of mammary grafts seems justified. Function of the right internal mammary graft to the circumflex marginal artery was suboptimal, and this method has been discontinued. All other complex mammary techniques had excellent patency rates as compared to vein grafts, and these differences may become even more significant in the late postoperative period.(ABSTRACT TRUNCATED AT 400 WORDS)     

Coronary artery bypass grafting with the right gastroepiploic artery

The excellent results of coronary artery bypass with the internal mammary artery and the increasing numbers of patients who need coronary reoperations, but for whom conventional bypass conduits are not available, have prompted us to evaluate alternative arterial bypass conduits. The right gastroepiploic artery has been used as a coronary bypass graft in 36 patients (32 men), whose ages ranged from 29 to 71 years. Twenty-two patients had had previous coronary bypass grafting and six of these were undergoing their third bypass operation. The right gastroepiploic artery was used as an in situ graft to the right coronary artery or circumflex branches for 17 patients and as an aorta-coronary ("free") graft in 19 patients, six to the left anterior descending or diagonal, six to the circumflex, and seven to the right coronary artery. In conjunction with right gastroepiploic artery grafting, 16 patients received bilateral internal mammary artery grafts and 17 received one internal mammary artery graft. Histologically, right gastroepiploic artery segments from 18 patients could not be distinguished from internal mammary artery segments, and no evidence of atherosclerosis was found. Two patients died in the hospital, one intraoperatively and one 3 months after the operation, of a perioperative stroke. Perioperative morbidity included wound complication in three and reexploration for bleeding in two. At late follow-up 1 to 38 months after operation, two late deaths had occurred and 21 patients were free of symptoms. Postoperative angiography (postoperative interval 1 week to 13 months) was performed in nine grafts, three in situ grafts to the right coronary artery and six free grafts that included two to the left anterior descending, three to the circumflex, and one to the right coronary artery. All right gastroepiploic artery grafts were patient. The right gastroepiploic artery is an arterial conduit that can be used as an in situ graft to posterior coronary vessels and as a free graft to any coronary arterial system. Early graft patency has been excellent, and the histologic similarity between the right gastroepiploic artery and the internal mammary artery suggest that the long-term results will be favorable.     

Coronary endarterectomy

From July, 1984, to December, 1986, coronary bypass grafting was performed in 314 patients, 70 (22%) requiring coronary endarterectomy (RCA; 48 pts, LAD; 10 pts, LAD + RCA; 10 pts, Others; 2 pts). Coronary endarterectomy patients (END group) were younger and often with the risk factor of hyperlipidemia than non-endarterectomy patients (NON group). The over-all hospital mortality rate of END group was 7 per cent; perioperative myocardial infarction occurred in 7 per cent of patients. Early postoperative angiogram (4 weeks after the operation) was performed in 54 patients. The patency rate of RCA endarterectomy was 81.8 per cent, and that of LCA endarterectomy was 75 per cent. This result was poor compared with the patency rate of non-endarterectomy graft (86.6%). However without endarterectomy, with all likelihood the patency rate of those grafts would have been poorer. The results of right coronary endarterectomy are satisfactory and better than those of the left coronary artery system. This experience suggests that coronary endarterectomy is safe and an useful adjunct of saphenous vein bypass grafting procedures in the management of diffuse coronary disease, especially in RCA lesions.     

Patterns of patency of 596 vein grafts up to seven years after aorta-coronary bypass.

The long-term behavior of vein grafts and their effect on the native circulation were studied by examining 596 vein grafts in 343 patients at a mean follow-up of 15.4 months, range zero to 84 months. Serial studies were performed on 27 patients with 38 grafts. The over-all graft patency rate was 84 per cent, and the rate after more than 5 years was 89 per cent. The patency rate in asymptomatic patients was 91 per cent compared with 81 per cent in the remainder. The patency of grafts attached distal to total occlusions was 82 per cent (78/82). The angle of origin of the grafts from the aorta did not appear to influence patency or the severity of intimal proliferative changes. In 76 patients with 126 grafts, pre- and postoperative cineangiograms were compared, and changes in the graft and underlying coronary artery classified as Groups 1 to to 6: Group 1, patent graft, bidirectional flow in the grafted vessel, proximal lesion unchanged; Group 2, patent graft, bidirectional flow, proximal lesion progressed to occlusion locally; Group 3; patent graft, distal flow only, occlusion of lesion and segment between graft and lesion; Group 4, graft occluded, native artery unaltered; Group 5, graft occluded, native artery now occluded at lesion and region of anastomosis; Group 6, new distal lesion. Results were as follows; Group 1, 58 per cent; Group 2, 21.2 per cent; Group 3, 5 per cent, Group 4, 12.5 per cent; Group 5, 2.5 per cent; and Group 6, 0.8 per cent. Native coronary arteries undergoing closure (Group 2) had lesions 95 per cent or greater in 93 per cent of patients. The rate of closure of ungrafted lesions was 2 per cent. We believe these results encourage the continued used of vein bypass grafts.     

Crossed double internal mammary-to-coronary artery grafts.

Crossed double internal mammary (IMA)-coronary artery grafts (the left to the left anterior descending artery [LAD], the right to a diagonal or marginal coronary branch) were used without mortality and with excellent functional results in 36 patients requiring separate grafts to these vessels (22% of patients undergoing coronary revascularization). Flows were 70 +/- 9 ml/min in the left and 50 +/- 7 ml/min in the right IMA, respectively. All revisualized grafts remained patient. The location and direction of the LAD and of diagonal and marginal branches allow excellent alignment of these shorter and wider double IMA grafts. The left IMA is the graft of choice for the LAD, and the right IMA is the choice for a high diagonal or early arising marginal branch that requires an additional separate graft. The right IMA is not satisfactory for right coronary or LAD bypass.     

The efficacy and safety of additional bypass graft during isolated coronary artery bypass grafting.

In 19 patients with an undesirable hemodynamic condition (n=15) or with regional asynergy and coexistent ST-T change (n=4) during isolated coronary artery bypass grafting (CABG) surgery, one (n=17) or two (n=3) additional saphenous vein grafts were placed onto left anterior descending (LAD) (n=16), right (n=4), and left circumflex (LCx) (n=2) coronary arteries. Diagnosis of the cause of the suboptimal condition was insufficient graft flow in 16 patients, and spasm of the ungrafted coronary artery in 3. Additional myocardial ischemic time was 17 9 minutes, and the graft flow was 59 25 ml/min. Additional bypass was effective in 94.5%. Eighteen patients could be weaned from cardiopulmonary bypass, and 17 (89.5%) survived and were discharged from hospital. Median duration of mechanical ventilatory support and intensive care unit stay was 15 hours and 4 days, respectively. During 63 44 months follow-up, the additional graft was occluded and the treadmill test was positive for ischemia in 2 patients, and one child patient is now considered for redo CABG. Placement of additional bypass grafts thus appeared to be an effective and relatively safe strategy, although the decision has to be made cautiously.     

Coronary revascularization using only arterial grafts in patients with left main coronary artery stenosis]

Although increasing use is being made of arterial grafts (internal thoracic arteries and right gastroepiploic artery) for coronary revascularization, application to left main coronary artery (LMT) patients is frequently not possible. During the period from December 1989 to July 1991, coronary revascularization was conducted on 9 LMT patients using only arterial grafts and no venous grafts. The bypass grafts were 6 left internal thoracic artery grafts, 9 right internal thoracic artery grafts and 9 right gastroepiploic artery grafts, a total of 24 grafts and an average of 2.7 bypasses per patient. There were no operated deaths, but five patients required IABP support after cardiopulmonary bypass. They had more than 90% stenotic lesions of left main coronary artery. In contrast, four patients with less than 90% stenotic lesion were uneventful. The cause of these catastrophic hemodynamics was considered reduced blood flow by graft spasm. All patients could be functionally placed in New York Heart Association Class I or II. Postoperative stress tests were made on eight patients and the results were normal in seven. Eight patients have had postoperative angiograms. Twenty-one of 22 grafts were patent. The present results demonstrate that an arterial bypass is possible even on LMT patients by IABP support.     

Selection of coronary bypass. Anatomic, physiological, and angiographic considerations of vein and mammary artery grafts.

Results of direct coronary revascularization with 511 grafts in 213 patients from 1971 to 1974 are reviewed. To improve an early saphenous vein graft (SVG) patency of 84 per cent in the first 85 patients, we have used internal mammary artery grafts (IMAG), when possible, since January, 1973. In 1973 to 1974, 15 patients had SVG's only (36 grafts) and 113 received one or two IMAG's with or without additional SVG's (total 282 grafts); in 26 we used a crossed double IMAG. Forty-seven of 48 patients with unstable angina survived and did well. Flows in SVG's and IMAG's were comparable. Flows in right IMAG's to diagonal or marginal vessels were higher than in right IMAG's to right or left anterior descending (LAD) vessels. In 12 patients with both SVG and IMAG, there was no difference in flow response of either graft to vasoactive drugs. Survival, functional, and patency results with IMAG's were as good as or better than results with SVG's. We conclude that IMAG's yield higher patency and comparable flow rates to SVG's and should be used when the IMA approximates the recipient artery in size and when a high pulsatile free flow is measured from the end of the graft. IMAG's are also safe and feasible for unstable angina.     

Patency of saphenous vein coronary artery bypass grafts from the vascular prosthesis of the ascending aorta.

BACKGROUND: Patients who have Stanford type A aortic dissection with impaired coronary arteries or who have aneurysms from the ascending aorta to the aortic arch with coronary artery disease need coronary artery bypass grafting (CABG) with tube graft replacement of the ascending aorta simultaneously. When vein grafts are used for CABG in these patients, the proximal anastomoses of vein grafts are attached to the prosthetic tube graft of the ascending aorta. However, the validity of proximal anastomoses of vein grafts to the prosthetic tube graft of the ascending aorta has not been confirmed. PATIENTS AND METHODS: We retrospectively analyzed patients who underwent venous coronary bypass grafting with prosthetic graft replacement of the ascending aorta. Between January 1984 and October 2002, 35 patients underwent CABG using saphenous vein grafts at the time of tube graft replacement of the ascending aorta, and the proximal anastomoses of the vein grafts were attached to the tube graft of the ascending aorta. Thirty-three venous bypass grafts were analyzed in 24 survivors. RESULTS: The postoperative catheterization showed only one early vein graft occlusion of 16 vein grafts anastomosed distally to the left anterior descending artery (LAD). All 14 venous grafts anastomosed to the right coronary artery (RCA) and 3 to the left circumflex artery (LCX) were patent. Therefore, the postoperative patency rate at discharge was 97.0% (32/33). Spiral computed tomography performed for long term follow-up revealed occlusion of two vein grafts (3.5 years and 9.7 years) anastomosed to the LAD. CONCLUSIONS: The patency rate of vein grafts anastomosed from prosthetic grafts of the ascending aorta to the native coronary arteries was similar to that of conventional CABG using saphenous vein grafts.     

Surgical versus medical treatment of coronary artery disease. Nine year follow-up of 9,061 patients.

To ascertain whether surgical therapy increases the life expectancy of patients with coronary artery occlusive disease, 9,061 consecutive patients undergoing aortocoronary bypass from July 1968 through June 1977 were reviewed and followed for up to nine years.Among all patients undergoing aortocoronary bypass without concomitant procedures, early mortality was 3.5 per cent (9.1 per cent in 1970 and 1.7 per cent during 1977). Late mortality was significantly lower in those patients receiving four grafts or more (0.7 per cent) and triple grafts (2.2 per cent) compared with patients undergoing either double grafts (4.4 per cent) or single grafts (3.5 per cent). This emphasizes the importance of complete revascularization. Nine year follow-up determined that 91.0 per cent of surviving patients were asymptomatic or significantly improved.Actuarial (Cutler) curves including early and late mortality demonstrated that 92 per cent of patients were alive at three years and 80 per cent at nine years after aortocoronary bypass. These results compare favorably with those of the recently published randomized Veterans' Administration Cooperative Study, which reported that at three years 87 per cent of medically treated patients were alive. Their follow-up extended only three years, but if their actuarial curves are projected to nine years, only 61 per cent of medically treated patients will be anticipated to be alive, compared to 80 per cent of patients treated surgically in the present series. These data suggest that surgical treatment of patients with coronary artery occlusive disease significantly improves long-term survival.     

Anomalous origin and distribution of coronary arteries. Review of 38 patients who underwent operation.

Between October 1961 and December 1973, 38 patients with an anomaly in origin (15 patients) or distribution (23 patients) of the main coronary artery or one of its branches underwent operation at the Texas Heart Institute. The left coronary artery originating from the pulmonary artery occurred most frequently-in 13 of 15 patients. An aortocoronary artery bypass was performed in 12 patients with the saphenous vein used in ten of the 12, initially in 1965; and a Dacron tube graft in the other two. Of the 15 patients, only one died during the early period after operation. A follow-up of ten years revealed 11 asymptomatic patients; to date the longest period of patency of a saphenous vein graft is seven years in an 11-year-old girl. Of 23 patients with an unusual coronary artery distribution, 22 had tetralogy of Fallot, 20 of whom underwent total correction. In 21 of the 23 patients the left anterior descending coronary artery originated from the right coronary artery and crossed the right ventricular outflow tract. In two patients this abnormally distributed artery was injured through a vertical right ventriculotomy; both patients died from myocardial failure during the early postoperative period. Subsequently a transverse right ventriculotomy, either alone or combined with a right ventricular outflow and/or pulmonary artery patch enlargement was performed in 16 patients, and a double outlet right ventricle was created through insertion of a Dacron tube graft in two patients. With this method injury to the abnormal left anterior descending coronary artery was avoided and all 18 patients survived the operation. On the basis of our experience and today's advanced techniques, it is believed that most patients, including some under two years of age, can undergo correction of a left coronary artery originating from the pulmonary artery through insertion of a saphenous vein graft between the aorta and left coronary artery. During the surgical correction of cardiac anomalies necessitating a right ventriculotomy, a transverse or double incision in the right ventricular outflow tract in most patients will prevent injury to an abnormally distributed coronary artery branch; sometimes insertion of a Dacron tube graft between the right ventricular outflow tract and pulmonary artery is necessary.