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Objective: We have developed a technique for biologic coronary artery bypass grafting, which is a revival of a classic concept with modern biotechnology., Methods: Acute myocardial infarction was created by ligating the major branch of the circumflex artery in rabbits. Animals were divided into four groups: a nontreated group (group N), a group in which omentum was used to wrap the infarcted area (group G), a group in which a gelatin hydrogel sheet incorporating 100 microg basic fibroblast growth factor was placed over the infarcted area (group F), and a group in which the infarcted area was similarly treated with basic fibroblast growth factor followed by omental wrapping (group FG). Cardiac function was subsequently assessed by echocardiography. Postmortem angiography through the gastroepiploic artery was done in groups G and FG. Infarct size and arteriolar density were evaluated., Results: Group FG showed a better fractional area change than did the other groups (group N P <.001, group G P =.002, group F P <.001). Angiography revealed that communication from the gastroepiploic artery to the coronary artery was created through a rich bed of neovascularization in all 7 animals of group FG, whereas poor collaterals were recognized in only 2 of 7 animals in group G. Infarct size was reduced to a greater extent in group FG than in groups F, G, and N (10% +/- 3%, 16% +/- 5%, 19% +/- 7%, 23% +/- 2%, respectively, group F P =.04, groups G and N P <.01). The number of arterioles 20 to 100 microm in diameter was increased to a greater extent in group FG than in groups F, G, and N (23 +/- 5 arterioles/mm(2), 14 +/- 3 arterioles/mm(2), 10 +/- 1 arterioles/mm(2), 4 +/- 2 arterioles/mm(2), respectively), with the differences being significant., Conclusions: These results show that bypass from the gastroepiploic artery to coronary arteries can be achieved without surgical anastomosis through slow release of basic fibroblast growth factor in this rabbit acute myocardial infarction model. This new revascularization concept, biologic coronary artery bypass grafting, could be applicable for revascularizing many tiny coronary vessels in patients who are difficult to treat with conventional surgery or catheter intervention.

Objective: The angiographic patency of the right gastroepiploic artery graft used for coronary artery bypass grafting was studied during the late (5-10 years) postoperative period., Methods: Among 936 patients undergoing a gastroepiploic artery graft for coronary artery bypass grafting between 1986 and 1999, postoperative angiographic restudy was conducted on 685 patients within 1 year (mean, 2.2 months), on 102 patients between 1 and 5 years (mean, 2.3 years), and on 52 patients between 5 and 10 years (mean, 7.8 years)., Results: The patency rate of the gastroepiploic artery graft was 94%, 88%, and 83% in each restudy group. The cumulative patency rate estimated by the Kaplan-Meier method was 96.6% at 1 month, 91.4% at 1 year, 80.5% at 5 years, and 62.5% at 10 years. Causes of late occlusion were primary anastomotic stenosis and anastomosis to a less critically stenosed coronary artery. Once the gastroepiploic artery was perfectly anastomosed to the coronary artery, which has tight stenosis and good runoff, late patency was good, and new stenosis in both the gastroepiploic artery trunk and the anastomotic site was uncommon., Conclusion: The gastroepiploic artery graft can be used effectively for coronary artery bypass for the long term with proper target selection.

Objective: To treat end-stage cardiomyopathy, we evaluated endoventricular circular patch plasty, partial left ventriculectomy, and valvular reconstruction alone in our 2-year experience., Methods: Among 86 patients with heart failure evaluated between December 1996 and February 1999, 33 patients with ischemic cardiomyopathy (25 men and 8 women; mean age 61 +/- 7.8 years; New York Heart Association class 3.5 +/- 0.5) were treated with endoventricular circular patch plasty combined with coronary bypass grafting (84%) and mitral reconstruction (36%). The other 53 patients with nonischemic cardiomyopathy (45 men and 8 women; mean age 48 +/- 14.3 years, New York Heart Association class 3.7 +/- 0.5), were treated by left ventricular reduction by partial left ventriculectomy (n = 37) or patch plasty (n = 3) and valve reconstruction alone (n = 13). The first 24 patients (group I) underwent ventriculectomy with or without valve reconstruction; the more recent 29 patients (group II) underwent left ventricular reduction (n = 16) or valve reconstruction alone (n = 13) on the basis of the intraoperative echocardiographic evaluation to observe changes of wall motion and thickness during cardiopulmonary bypass., Results: Ischemic Group: Hospital mortality in elective (n = 26) and emergency (n = 7) operations was 4% and 43%, and 3 patients died in the late postoperative period. Mean New York Heart Association class and ejection fraction improved from 3.5 +/- 0.5 to 1.5 +/- 0.7 and from 23% +/- 7.7% to 36% +/- 8.6%, respectively. Left ventricular end-diastolic and end-systolic volume indexes decreased from 162 +/- 46 mL/m(2) to 110 +/- 39 mL/m(2) and from 130 +/- 47 mL/m(2) to 70 +/- 32 mL/m(2), respectively. Nonischemic Group: In 40 patients with left ventricular reduction, hospital mortality in elective (n = 33) and emergency (n = 7) operations was 6% and 86%, and 5 patients died in the late postoperative period. Mean New York Heart Association class and ejection fraction improved from 3.7 +/- 0.5 to 1.7 +/- 0.6 and from 18% +/- 6.4% to 31% +/- 5.9%. Left ventricular end-diastolic and end-systolic volume indexes decreased from 203 +/- 45 mL/m(2) to 110 +/- 37 mL/m(2) and from 164 +/- 40 mL/m(2) to 79 +/- 33 mL/m(2), respectively. In 13 patients undergoing valve reconstruction alone (12 mitral with or without tricuspid and 1 tricuspid plus left ventricular assist device), hospital mortality in elective (n = 9) and emergency (n = 4) operations was 0% and 50% with no late deaths. Mean New York Heart Association class and ejection fraction improved from 3.6 +/- 0.5 to 2.0 +/- 0.5 and from 22% +/- 6.0% to 30% +/- 14.5%, respectively. Mean left ventricular end-diastolic and end-systolic volume indexes decreased from 170 +/- 34 mL/m(2) to 150 +/- 50 mL/m(2) and from 140 +/- 38 mL/m(2) to 104 +/- 40 mL/m(2), respectively. Overall mortality decreased from 50% in group I to 10% in group II. The survival estimates at 2 years were 77% (confidence limits 57%-88%) in the ischemic group and 63% (confidence limits 47%-75%) in the nonischemic group (no significant difference). The analysis of our data showed that the factors influencing the surgical results for dilated cardiomyopathy were presence of severe mitral regurgitation, preoperative New York Heart Association functional class IV with emergency operation, and operative procedures with randomly performed partial left ventriculectomy without an intraoperative echo test., Conclusion: Endoventricular circular patch plasty, partial left ventriculectomy, and solo valve reconstruction can be performed with an acceptably low risk as elective operations. The selection of operative procedures in idiopathic dilated cardiomyopathy and avoidance of emergency surgery improved operative mortality and morbidity. Among patients who survived at least 1 year, there were no late deaths up to 30 months' follow-up.

To identify predictors of arterial graft patency, we followed up 30 internal thoracic arterial grafts and 23 right gastroepiploic arterial grafts in situ with patency documented during postoperative angiography. After 24 months of follow-up on average, repeat angiography detected that one internal thoracic artery and two gastroepiploic arteries were anatomically occluded and that the other three gastroepiploic arteries were nonfunctioning. The logistic regression model identified a relationship between graft patency and competitive flow, which was detected as stenosis in the recipient coronary arteries (coefficients, p < 0.05; model, Hosmer-Lemeshow chi2 statistic 3.59, p = 0.89). The linear regression model demonstrated that changes in graft luminal diameter correlated with competitive flow (p < 0.01), smoking history (p < 0.05), and type of arterial grafts (p < 0.001) (R2 = 0.40, adjusted R2 = 0.36). The findings suggest a temporal relationship between competitive flow and prognosis of arterial graft.

From March 1986 to September 1991, the right gastroepiploic artery has been used for coronary artery bypass grafting in 200 patients (171 male and 29 female patients, mean age 58 years, range 6 to 80 years. They were followed up from 6 to 70 months with a mean of 27 months. There were 16 reoperations and 176 patients had triple vessel or left main disease. The gastroepiploic artery (182 in situ and 18 free grafts) was anastomosed to 11 anterior descending, 3 diagonal, 26 circumflex, and 160 right coronary arteries. The internal thoracic artery was concomitantly used in 192 patients. The mean number of distal anastomoses was 2.3 with arterial grafts and 3.3 including additional saphenous vein grafts. Postoperative angiography was performed in 152 patients within 6 months after the operation (mean 2 months) and after the operation second angiograms were done sequentially 1 to 5 years (mean 2 years) after the operation in 40 patients. There were 6 early and 4 late deaths. A new Q wave was noted in 4 patients. Duration of the operation and postoperative complications did not increase with the use of the gastroepiploic artery. Relief of angina was noted in 186 patients. Gastroepiploic artery graft patency was 95% (144/152) in the early postoperative period and 95% (38/40) in the late postoperative period. Percutaneous transluminal coronary angioplasty was done successfully through the in situ gastroepiploic artery graft for anastomotic stenosis in four cases. In stress myocardial scintiscans, performed sequentially preoperatively and in the immediate, 1-year, and 2-year postoperative periods in 11 patients, washout rate of the gastroepiploic artery-grafted area improved from 35% +/- 10% to 45% +/- 15% (p < 0.05) and was maintained to 43% +/- 6% and 48% +/- 9% at respective periods. In conclusion, the gastroepiploic artery is a suitable conduit for coronary artery bypass grafting in terms of low surgical risk, high patency rate, and excellent patient outcome.

We examined the responses of human gastroepiploic arteries to histamine, serotonin, and norepinephrine, comparing those of internal mammary arteries and saphenous veins. Fresh specimens of the vessels were obtained intraoperatively from 21 patients. The vessels were suspended in organ chambers to record isometric tensions. With gastroepiploic arteries, histamine induced relaxations in the endothelial rings (85% +/- 7%) but failed to induce any contractions or relaxations in the rings without endothelium. The relaxations were prevented by methylene blue or hemoglobin and the H1-histaminergic receptor antagonist chlorpheniramine. With internal mammary artery rings with endothelium, histamine at a low concentration (10(-8) to 10(-5.5) mol/L) induced relaxations (53% +/- 12%) but evoked contractions at a higher concentration (10(-5) to 10(-4.5) mol/L). With saphenous veins, histamine caused only contractions. Serotonin induced markedly greater contractions in saphenous veins than in either artery. The endothelium inhibited the maximal contraction in response to serotonin in both arteries but not in veins. With the gastroepiploic artery, the responses to norepinephrine and serotonin were similar to those of the internal mammary artery. Histamine induces endothelium-dependent relaxations only, and histaminergic receptors that induce contractions may be absent on vascular smooth muscle cells. These vasoactive properties may contribute to the high patency as a coronary graft.

Seventy patients in whom the gastroepiploic artery was used for coronary artery bypass grafting were compared with 70 patients in whom the gastroepiploic artery was not used. Mean age was 56.8 years in the group in which this artery was used and 61.8 years in the group in which it was not (p less than 0.001). All other preoperative characteristics including number of women, extent of coronary artery disease, previous myocardial infarction, unstable angina, and preoperative left ventricular function were not significantly different between the two groups. An internal mammary artery graft was concomitantly used in 68 patients (97%) of the group with a gastroepiploic artery graft and in 61 patients (87%) without such a graft. The mean number of distal anastomoses was 3.3 and 3.4, aortic crossclamp time was 65.3 +/- 19.9 minutes and 54.0 +/- 20.1 minutes, and cardiopulmonary bypass time was 114.8 +/- 23.6 minutes and 112.9 +/- 25.0 minutes, respectively, in the groups with and without a gastroepiploic artery graft. Only aortic crossclamp time was significantly (p less than 0.05) longer in the group with a gastroepiploic artery graft. There were two (2.9%) early deaths and two (2.9%) new Q-wave infarctions in both groups. Intraaortic balloon pumping was required in five patients (7.1%) in the group with a gastroepiploic artery graft and in three patients (4.3%) without this graft. Postoperative complications were similar and rare in both groups. Intraoperative endoscopic laser Doppler study demonstrated no significant change of gastric mucosal blood flow before and after division of the gastroepiploic artery. We concluded that there is no additional risk in the use of the gastroepiploic artery for coronary bypass grafting, and a favorable outcome can be expected.

The results of internal mammary artery grafting in 50 patients with a body surface area less than 1.6 m2 were compared with those in 54 patients with a larger body surface area. Age (58.8 +/- 8.2 versus 54.9 +/- 10.3 years old) and prevalence of female gender (28% versus 4%) were significantly different between the group of patients with a small body surface area and the group with a large body surface area, respectively. However, the prevalence of unstable angina, previous myocardial infarction, extent of coronary artery disease, and preoperative ejection fraction was not significantly different between the two groups. The mean number of distal anastomoses was 3.0 and 2.8, and the mean duration of aortic occlusion was 65.6 +/- 23.0 minutes and 59.5 +/- 21.7 minutes in the small and large body surface area groups, respectively (not significant). The mean free flow rate of the internal mammary artery was 65.6 +/- 16.8 ml/min in the small body surface area group and 78.0 +/- 21.6 ml/min in the large body surface area group (p less than 0.05). The diameters of the anterior descending and the circumflex arteries were significantly smaller in the small body surface area group. Two patients (4%) died within 30 days of operation and one patient died later in the small body surface area group, whereas no death was noted in the large body surface area group (not significant). No significant differences were found in the incidence of aortic balloon pumping, perioperative myocardial infarction, and serious postoperative complications between the two groups. Symptomatic relief was equally good in both groups (92% and 96%). The patency rate of the internal mammary artery was 95% (42/44) in the small body surface area group and 100% (48/48) in the large body surface area group within 1 year, mean 2.3 +/- 2.4 months. In conclusion, internal mammary artery grafting can be performed safely and effectively even in patients with small body structure. Though the blood flow of the internal mammary artery and the size of the coronary arteries were smaller in patients with small body structure, excellent patency of the internal mammary artery graft and satisfactory symptomatic relief can be expected.