Multivessel coronary revascularization with bilateral internal thoracic artery grafts

Sixteen patients underwent coronary revascularization with bilateral internal thoracic artery (ITA) grafts between 1988 and 1989 at the Okayama University Hospital. A total 39 coronary grafts were performed, being an average of 2.4 grafts per patient. Each patient received bilateral ITA grafts, and in 5 patients an additional 7 grafts were constructed with 5 autologous veins and 2 gastroepiloic arteries. The right ITA was grafted as a free graft in 4 patients. The ITA graft patency rate was 96.8 per cent (31/32) at the time of hospital discharge. The postoperative morbidity included one reoperation for bleeding and one myocardial infarction. Coronary artery bypass grafting with bilateral ITA grafts can be safely performed and its application facilitates complete revascularization with arterial grafts.     

Coronary revascularization with bilateral internal thoracic artery grafts]

Thirty-two patients underwent coronary revascularization with bilateral internal thoracic artery (ITA) grafts. Each patient received 2.7 grafts in average including double ITA grafts. Seventeen patients had the right ITAs as free grafts. The other sixteen were treated with 13 autologous veins and 9 right gastroepiploic arteries in addition. Fifty-five grafts out of 56 (98.2%) were proved to be patent at the time of hospital discharge. The postoperative morbidity included three reoperations for bleeding and one perioperative inferior myocardial infarction. One patient died of colon perforation after surgery and another died of cerebral infarction late after surgery. These results exhibited that coronary artery bypass grafting with bilateral ITA grafts had relatively low risks and could contribute to complete revascularization in patients with diseased coronary arteries.     

Spontaneous recanalization of functionally occluded bilateral internal thoracic artery T graft

Functional occlusion of the left internal thoracic artery T graft is reported. The patient underwent triple coronary artery bypass grafting with bilateral internal thoracic artery, anastomosing in situ to the left internal thoracic artery to the left anterior descending artery, free right internal thoracic artery to the obtuse marginal and posterolateral branch of the left circumflex artery. Early angiography showed occlusion of the in situ left internal thoracic artery to the moderately stenosed left anterior descending artery and patent side arm to circumflex. However, mid-term angiography revealed restoration of the left internal thoracic artery flow. A negative exercise stress test was noted throughout the postoperative period. Flow competition with a native coronary artery may be responsible for functional occlusion of the left internal thoracic artery.     

Adequacy of flow capacity of bilateral internal thoracic artery T graft.

BACKGROUND: With the T graft configuration, multiple arterial revascularization can be accomplished using bilateral internal thoracic arteries. However, concern remains about the flow capacity of the main stem of the left internal thoracic artery (LITA). METHODS: Forty patients who underwent multiple revascularization of the entire territory of the left coronary system with a T graft were investigated. Six months after the operation, they were examined angiographically. During the same period, dobutamine stress echocardiography was performed to evaluate the adequacy of the myocardial blood supply from the T graft. The T graft revascularized two branches in 5 patients, three branches in 23, four branches in 11, and five branches in 1 of the left coronary system. Other conduits were used if revascularization was required for the right coronary system. RESULTS: Complete revascularization was achieved in the left coronary territory in all patients. The LITA main stem showed a wide lumen in all patients. Luminal narrowing was present in the distal segment of the LITA in 3 patients. The right internal thoracic artery (RITA) was patent in all patients, whereas luminal narrowing was observed in the distal segment of the RITA in 5 patients. No patient exhibited ischemic wall motion abnormality in the anteroseptal, lateral, or posterolateral region of the left ventricle where the T graft revascularized. Eight patients showed ischemic response in the inferoposterior region, that is, the territory of the right coronary artery. CONCLUSIONS: The LITA main stem, forming a T-graft configuration with the free RITA, has an adequate flow reserve to supply at least the entire left coronary arterial system with sufficient blood. Therefore, multiple coronary revascularization using the T-graft technique is feasible.     

Free internal mammary artery graft in myocardial revascularization

Between August 1986 and March 1993, 124 patients (102 men; mean age of 59 years) underwent myocardial revascularization with the use of at least one free internal mammary artery (FIMA). This group represents 4.5% of the 2725 coronary bypasses performed during the same period. Seventy-six patients (61%) had suffered from at least one previous myocardial infarction. Forty-five patients (36%) had unstable angina; three-vessel disease was found in 100 cases (80.5%) and a left ventricular ejection fraction lower than 0.4 in 22 (17.7%). There were 18 (14.5%) redo procedures and 90 (72.5%) bilateral internal mammary artery (IMA) grafts. The reasons for using a FIMA were: too short an internal mammary artery pedicle in 83 patients, IMA injury at harvesting in 30 patients and post-bypass ischaemia in areas grafted with pedicled IMA (PIMA) in 11 patients. Cardiopulmonary bypass, moderate hypothermia (30 °C) and crystalloid anterograde and retrograde cardioplegia were used in all cases. Sixty-seven FIMA grafts were anastomosed directly to the ascending aorta; 57 were sutured via a saphenous hood using a running suture of polypropylene 7/0 and three were anastomosed end-to-end to a PIMA graft. FIMA grafts were directed to the left anterior descending (34%), the circumflex (37%) and the right coronary artery (29%). In total, 179 anastomoses were constructed using 127 FIMA, 136 using PIMA and 158 using saphenous veins (3.8 anastomoses per patient). Hospital mortality and postoperative myocardial infarction rates were 5.6% (seven patients) and 3.2% (four patients), respectively. Cardiac-related mortality was 3.2% (four patients); three of these four patients had been operated on for evolving infarction and one underwent a redo procedure. Four of the 117 survivors died later on; in two, it was cardiac-related and a result of global heart failure at 9 and 12 months. Of the 113 remaining patients, 106 are symptom free after a mean follow-up of 28.2 (range 3–84) months. Fifty-nine patients (50.4%) were restudied by angiography at a mean interval of 15 months. Patency rates of FIMA anastomosed either directly to the aorta or via a saphenous hood were 82.8 or 89.7%, respectively. Patency rates of FIMA directed to the left anterior descending, the circumflex and the right coronary artery were 85.7, 88 and 83.3%, respectively. Global FIMA patency was 86.4%, while global PIMA patency was 100%. The FIMA mid-term patency rates compare unfavourably with those of PIMA: FIMA should therefore be restricted to the cases where PIMA or other pedicled arterial grafts are unavailable.     

Bilateral internal thoracic artery T grafting for coronary artery revascularization

OBJECTIVES: We studied the early outcome of bilateral internal thoracic artery T grafting. METHODS: Coronary artery bypass grafting was studied retrospectively using bilateral internal thoracic artery T grafting in 51 patients. The T graft was made by anastomosing the free right internal thoracic artery to the in-situ left internal thoracic artery. Average patient age was 63.5 +/- 9.9 years, and the average number of anastomoses per patient was 3.6 +/- 0.9. In 35 patients, the right gastroepiploic artery (21 anastomoses in 20 patients), radial artery (1 anastomosis), free left internal thoracic artery (1 anastomosis) and saphenous vein graft (14 anastomoses in 13 patients) were used as additional bypass conduits. RESULTS: Hospital mortality was 0%. The morbidity of stroke was 1.9% (1 patient) and deep sternal infection 0%. Patency of the in-situ left internal thoracic artery was 49/50 anastomoses (98%) and that of the free right internal thoracic artery 81/84 anastomoses (96.4%). Mid-term coronary angiography in 7 patients demonstrated patent anastomosis of the T graft. Acute myocardial infarction unrelated to graft failure occurred in 2 patients during follow-up. Other patients were evaluated by exercise stress tests every year and none exhibited myocardial ischemia in the areas of T graft coronary revascularization. Three-year actuarial survival rate was 100% and freedom from cardiac events 96%. CONCLUSIONS: The bilateral internal thoracic artery T graft provides satisfactory early and mid-term outcomes in properly selected patients.     

Pulmonary complications following myocardial revascularization with the internal mammary artery graft

A total of 106 patients participated in a clinical investigation to determine the incidence and etiology of pulmonary complications following myocardial revascularization with the internal mammary artery graft; 39 patients (group I), undergoing valve replacement or myocardial revascularization with vein grafts, served as control. The mammary artery was used for revascularization in the remaining patients. The pleura was opened during the dissection of the mammary graft in 34 patients (group II), but was left intact during harvesting of the internal mammary artery in 33 patients (group III). Inspiration and expiration chest X-rays were obtained during the first 3 months of convalescence to determine the presence of pleural fluid, the position of the left hemidiaphragm, and to asses diaphragmatic movement. Pleural effusions, left lower-lobe atelectasis, and elevation of the left hemidiaphragm were observed in all groups after operation, but were more commonly observed in those patients undergoing revascularization with the mammary artery graft. Postoperative chest X-rays just prior to discharge from hospital were normal in 69% of the control group, only 9% of patients in group II who had pleurotomy during mammary artery dissection, and 42% of group III. By 3 months, however, 95% of patients in groups I and II had normal chest X-rays, whereas 53% of patients in group II had persistent loss of left-lung volume related to the presence of left-lower-lobe atelectasis, left pleural effusions and organization of the postoperative hemothorax.(ABSTRACT TRUNCATED AT 250 WORDS)     

Myocardial revascularization with the left internal thoracic artery Y graft configuration.

BACKGROUND: The proved long-term patency of the left internal thoracic artery (LITA) has made it the conduit of choice for myocardial revascularization. Maximal utilizable LITA length can be achieved by using a semiskeletonizing harvest technique. Expanded LITA use with sequential and Y graft techniques allows for a wider territory of myocardial revascularization. METHODS: A retrospective analysis of 30 patients undergoing coronary artery bypass surgery with a LITA-Y graft between December 1994 and November 1996 was performed. In selected patients the LITA was cut to length and anastomosed to the left anterior descending artery (LAD), with the redundant length of LITA used as a free graft to the lateral circumflex and diagonal systems. The proximal end of the free LITA was anastomosed to the in situ LITA to form the Y graft. Selection criteria included: a) minimal distal disease in the LAD and circumflex systems; and b) graftable circumflex branches proximal to the mid free wall of the left ventricle, allowing total revascularization of the left coronary system with the Y graft. RESULTS: Thirty patients (22 male, 8 female) underwent the LITA-Y graft procedure. There were no deaths or episodes of myocardial infarction. One patient required inotropic and intraaortic balloon pump support. Two patients with isolated coronary ostial stenosis developed recurrence of angina due to occlusion of the free limb of the LITA. CONCLUSIONS: In patients with suitable coronary artery anatomy, the LITA-Y graft can be successfully performed with good short-term outcome, but may be contraindicated in the management of isolated coronary ostial stenosis.     

In situ right internal thoracic artery graft for revascularization of circumflex artery

In 285 patients, the right internal thoracic artery, routed through the transverse sinus, was in most cases anastomosed to the circumflex branches. In 278 cases, the left internal thoracic artery was simultaneously used for revascularization of the left anterior descending artery. Two patients died (mortality rate 0.7%). Postoperative early angiography on 278 patients revealed a high graft patency of 97.8% for the right internal thoracic artery and 96.9% for the left internal thoracic artery. A long-term follow-up study was performed on the first consecutive 115 patients who survived the operation. Seven patients died, 2 due to cardiac causes. Angiographic assessment was performed in 73 patients (67%) at an interval of 28.8 to 93.1 months (mean 58.9 months). Five right internal thoracic arteries were occluded and sledlike right internal thoracic artery grafts were present in 2 patients. Two of them had been confirmed in the previous early study to be not patent. Insufficient data was obtained in 4 patients. The perfect patency rate of the right internal thoracic artery was 89.9% (62/69). Five left internal thoracic arteries were occluded, providing a perfect patency rate of 92.3%. There was no significant difference between the success rate using the right internal thoracic artery and that resulting from using the left internal thoracic artery. We conclude that coronary revascularization using this technique provides good clinical results and excellent early and late patency of the right internal thoracic artery.     

Long-term follow-up of total arterial myocardial revascularization using exclusively pedicle bilateral internal thoracic artery and right gastroepiploic artery

Objective: In order to reduce remote cardiac events associated with graft occlusions, arterial conduits are being increasingly utilized in coronary artery bypass grafting (CABG). While the internal thoracic artery (ITA) is the graft of choice for CABG, it is sometimes difficult or impossible to obtain a complete arterial revascularization only with ITAs in three-vessel diseases. We present our experience with total arterial myocardial revascularization with bilateral internal thoracic artery (BITA) and right gastroepiploic artery (rGEA). Methods: From April 1994 to January 2004, 174 patients (165 male, mean age 55.9±7.4) underwent coronary artery bypass procedure with exclusive use of BITA and rGEA. Left ventricular ejection fraction ranged from 20 to 68% (mean 55.9±6.8%). Seven patients (4%) had poor ejection fraction (<0.30), 23 (13, 2%) had acute myocardial infarction, 14 (8%) had left main disease. The mean CPB time was 96.9±15.7 min and the mean cross clamping time was 70±14.2 min. The mean number of distal anastomoses was 3.3±0.5 per patient. Results: Early mortality was 1.7%. The patients were followed for up to 9 years (mean follow-up time 6.3±2.6 years). Actuarial freedom from cardiac death (including hospital death) was 97.6%, at 9 years after the operation. Actuarial freedom from angina and cardiac events at 9 years was 79, 5% and 77, 6%, respectively. No perioperative myocardial infarction occurred. None of the patients needed a redo-CABG after leaving the hospital. Conclusions: This study indicates that the myocardial revascularization in young patients with three-vessel disease using exclusively pedicle BITA and rGEA provides excellent 9-year patient survival and improvement in terms of freedom from return of angina pectoris and freedom from any cardiac-related event. These results encourage the more extensive use of BITA and rGEA in selected patients with three-vessel coronary disease.     

Expanded use of internal mammary artery graft for myocardial revascularization

To improve the early and late benefits of coronary artery bypass grafting, use of internal mammary artery grafts was expanded. The first 60 patients to receive two mammary artery-coronary artery anastomoses and supplemental saphenous vein grafts are reviewed. Altogether 210 grafts (3.5/patient) were performed, including 54 mammary artery grafts in situ, six of them as free grafts. In 12 patients the right internal mammary artery was placed through the transverse sinus to revascularize the circumflex artery, and the left mammary artery was placed to the left anterior descending artery. In the remaining 48 patients both internal mammary arteries were used to revascularize the left anterior descending and the right coronary artery. There were no perioperative deaths and no sternal infections. Postoperative complications included re-exploration for bleeding and diaphragmatic dysfunction. Late follow-up was complete. Of 60 patients observed for 1/2 to 4 years, 57 were asymptomatic. Exercise stress tests were performed in 58 cases and were normal in 56.     

Right internal thoracic artery through the transverse sinus in myocardial revascularization

Background. A major concern in evaluating dynamic cardiomyoplasty has been whether the synchronous stimulation of latissimus dorsi muscle is essential for benefit or not. We studied 10 patients to determine the efficacy of the systolic augmentation generated by the synchronous electrical stimulation of the latissimus dorsi muscle.

Methods. Left ventricular ejection fraction, end-systolic and end-diastolic volume indexes, and stroke volume index obtained during resting, peak exercise, and recovery periods (“on” values) were compared with those obtained 1 week after cessation of electrical stimulus (“off” values). Double product and estimated total body oxygen consumption at peak exercise were also calculated and compared.

Results. Higher ejection fractions (0.36 ± 0.07 versus 0.33 ± 0.06 at rest, 0.40 ± 0.07 versus 0.33 ± 0.07 peak exercise, and 0.37 ± 0.06 versus 0.31 ± 0.06 at recovery) and lower end-systolic volume indexes with relatively constant end-diastolic volume indexes were observed with the cardiomyostimulator on. Further, exercise response was better with the cardiomyostimulator on. Double product indirectly reflected better myocardial oxygen supply/demand ratio when on at peak exercise (17 ± 2.2 mm Hg × beats/min × 10⁻³ for on versus 19 ± 2.6 mm Hg × beats/min × 10⁻³ for off). Estimated total body oxygen consumption was improved at peak exercise when the cardiomyostimulator was functional (12 ± 2.7 mL · kg⁻¹ · min⁻¹ versus 11 ± 2.6 mL · kg⁻¹ · min⁻¹).

Conclusions. Current data suggest a true systolic assist during synchronous contractions of the latissimus dorsi muscle. It is thought, therefore, that synchronous electrical stimulation is essential for maximum benefit and all the beneficial effect of cardiomyoplasty certainly cannot be attributed to simple wrapping itself.     

Right coronary artery revascularization in patients undergoing bilateral internal thoracic artery grafting: comparison of the free internal thoracic artery with saphenous vein grafts

From April 1996 to July 1999, 241 consecutive patients underwent complete arterial revascularization with composite T-graft, including right coronary artery grafting with free right internal thoracic artery (ITA) (ITA group). They were compared with 127 bilateral ITA patients in whom saphenous vein grafts (SVG) was used for grafting the right coronary system (SVG group). The SVG group included more diabetics (40 vs. 29%), more emergency cases (21 vs. 12.4%), and the number of anastomoses per patient was higher (3.8 vs. 3.35, P=0.025). Thirty-day mortality was 3.9 and 4.1% in the SVG and the ITA groups, respectively (P=NS). Occurrence of perioperative complications (sternal infection, myocardial infarction, cerebrovascular accident, and bleeding) was not statistically significant. However, in sum, the complications rate was higher in the ITA group (8.3 vs. 2.4%, P=0.032). Midterm followup (2-56 months) showed increased return of angina in the ITA group (9.1 vs. 1.6%, P=0.00). However, 4-year survival (Kaplan-Meier) was comparable (91.7% in the SVG and 87% in the ITA group). In conclusion, early results of complete arterial revascularization with composite T-graft are similar to those of bilateral ITA grafting of the left and right system revascularization with SVG. However, lower return of angina in the SVG group makes SVG grafting preferable for the right coronary system.     

Arterial myocardial revascularization with in situ crossover right internal thoracic artery to left anterior descending artery

BACKGROUND: The extra length obtained by skeletonizing the internal thoracic arteries (ITAs) enables versatile use of in situ bilateral ITAs for coronary artery bypass grafting, as the longer skeletonized right ITA more easily reaches the anastomotic site on the left anterior descending coronary artery. METHODS: Between April 1996 and November 1999, 365 consecutive patients underwent revascularization with bilateral in situ ITAs (29% of 1,250 grafting procedures performed with both ITAs in our department during this period). The right ITA was routed anterior to the aorta to graft the left anterior descending coronary artery, and the in situ left ITA was used to graft circumflex branches. Right coronary artery branches were grafted with right gastroepiploic artery or saphenous vein graft. The right ITA crossed the midline above the aorta at the most cranial point to avoid damage in case of a repeat sternotomy in the future. RESULTS: The operative mortality rate was 2.2% (8 patients). Postoperative morbidity included seven strokes (1.9%), eight sternal wound infections (2.2%), and four perioperative myocardial infarctions (1.1%). Follow-up (6 to 49 months) of 97% of hospital survivors showed a return of angina in 3%. Postoperative coronary angiography (22 patients) revealed a 95% patency rate of both ITAs. One-year and 4-year survival rates (Kaplan-Meier) were 95% and 92.4%, respectively. Important predictors of an early unfavorable event were chronic obstructive pulmonary disease, old age (> or = 70 years), emergency operation, and diabetes. Chronic obstructive pulmonary disease was the only independent predictor of sternal wound infection (odds ratio, 15; 95% confidence interval, 2.8 to 80). It also predicted decreased late survival (hazard ratio, 8.3; 95% confidence interval, 3 to 21.5). CONCLUSIONS: With skeletonized dissection of ITAs, the right ITA easily reaches the left anterior descending coronary artery for left-sided arterial revascularization with in situ bilateral ITAs. This procedure is safe, but we recommend avoiding its use in patients with chronic obstructive pulmonary disease.