Artery Grafts For Myocardial Revascularization Research Articles

Left anterior descending artery revascularization with the right internal thoracic artery T-graft: the 'reverse composite' configuration.

The use of bilateral internal thoracic artery graft for myocardial revascularization has improved the long-term survival and decreased the rate of repeat interventions in patients. A key technical factor for complete arterial revascularization is sufficient length of the internal thoracic artery (ITA) graft. The purpose of this study was to compare early and long-term outcomes of 'standard composite' grafting and 'reverse composite' grafting. In the former, the left ITA (LITA) is connected to the left anterior descending artery, and the right ITA is connected end-to-side to the LITA for revascularization of the left circumflex artery. In 'reverse composite' grafting, the LITA is connected to the left circumflex artery, and the right ITA is connected end-to-side to the LITA, for revascularization of the left anterior descending artery. We compared the outcomes of 1365 patients who underwent coronary artery bypass grafting in Tel-Aviv Sourasky Medical Centre, using bilateral ITA as standard composite versus 'reverse composite' grafts, between January 1996 and December 2011. A propensity score matching analysis compared 132 pairs of patients who underwent bilateral ITA by the 2 modes. Twelve hundred and thirty patients underwent standard 'composite' grafts and 135 underwent 'reverse composite' grafts. Early mortality and early adverse effects did not differ significantly between the groups. After matching, the difference in late mortality between the groups was not statistically significant. This study suggests that revascularization of the left anterior descending with the right ITA, arising from an in situ LITA, is safe and provides early outcomes and long-term survival that are not significantly different from those of the standard composite grafting technique. However, there was evidence of better survival in the standard composite group.

Invited Commentary

Invited Commentary

Right Gastroepiploic Artery Graft for Myocardial Revascularization: Prevalence of Atherosclerosis and Availability as a Conduit

We evaluated prevalence of atherosclerosis and availability of right gastroepiploic artery graft in patients undergoing coronary artery bypass graft surgery. Among the 1,579 patients who underwent isolated coronary artery bypass grafting between January 1999 and December 2008, we opened the peritoneum to examine the right gastroepiploic artery for use as a graft in 1,128 patients (71.4%). A computer-based patient database system was utilized for this retrospective study. Of 1,128 patients, 139 patients (12.3%) had atherosclerotic right gastroepiploic arteries at gross examination. Seventy-three of 139 atherosclerotic right gastroepiploic arteries had multiple or diffuse atherosclerotic lesions that precluded their use as a bypass graft; the remaining 66 right gastroepiploic arteries were used as a bypass graft including the atheromatous segment or after exclusion of the atherosclerotic segment. Another 60 nonatherosclerotic right gastroepiploic arteries were unavailable to use as a graft because of their short length, small caliber, and weak pulsation. Overall availability of the right gastroepiploic arteries as a graft was 88.2% (995 of 1,128). Multivariable logistic regression analysis showed older age (≥65 years; p < 0.001), insulin-treated diabetes mellitus (p = 0.001), and chronic renal failure (p < 0.001) as independent risk factors for atherosclerosis. The prevalence of atherosclerosis and availability of the right gastroepiploic artery graft in patients undergoing isolated coronary artery bypass grafting was 12.3% and 88.2%, respectively. Older age (≥65 years), insulin-treated diabetes mellitus, and chronic renal failure were identified as independent predictors for the atherosclerotic right gastroepiploic artery.

Invited Commentary

There are enthusiasts for gastroepiploic artery (GEA) coronary bypass grafting on three continents, and a few surgeons have reported large experiences using this conduit, but 10-year patency is disappointing. Early patency of the free GEA has also been inferior, but the experience is small and early in the use of this conduit (ie, 3 of 4 reports from 1990 or before and 1 of 4 from 1993). The GEA graft has been attractive as an in situ conduit and used by some to achieve all arterial revascularization without aortic anastomosis when combined with the in situ internal thoracic arteries (ITAs). Despite this utility, there are several limitations and concerns. The GEA is less consistent in size than the ITA and the radial artery (RA), and its in-flow via the celiac axis may be compromised by atherosclerosis. The GEA also diminishes in diameter along its length to a greater degree than the ITA or RA, so that its useful length may be limited. Routing through the diaphragm is relatively straightforward and has not been identified as a cause of failure, but it does present the concern of angulation or kinking and the challenge of optimal placement to achieve a parallel approach to the target without compromising conduit length. Having a totally muscular media, such as the RA, it is more prone to spasm than the ITA, will usually benefit from topical or intraluminal vasodilators, or both, and it is vulnerable to competitive coronary flow. Also subsequent laparotomy may result in injury to the conduit. Initial harvesting was done with a bulky pedicle of omentum with a subsequent trend toward semi or true skeletonization, which is more attractive. The present report uses a free graft with a bulky pedicle and anastomosis of the gastroepiploic vein to the right atrial appendage. Most impressive is the 95.7% patency at a mean of 77 months in 46 patients. I believe the improved patency is a consequence of good surgical technique and free grafting that improves in-flow and addresses many of the previously mentioned concerns. The authors [1Eda T. Matsuura A. Miyahara K. et al.Transplantation of the free gastroepiploic artery graft for myocardial revascularization: long-term clinical and angiographic results.Ann Thorac Surg. 2008; 85: 880-884Abstract Full Text Full Text PDF PubMed Scopus (9) Google Scholar] suggest that venous drainage is the reason for improved patency, but they do not provide a control group. Historically, it has been suggested that the free ITA graft would be compromised without venous anastomosis but patency for it, the RA and the inferior epigastric artery disprove that viewpoint. The authors experience warrants consideration of preferential use of the GEA as a free graft from the aorta or the ITA without venous anastomosis and with a lean pedicle or skeletonized conduit. Transplantation of the Free Gastroepiploic Artery Graft for Myocardial Revascularization: Long-Term Clinical and Angiographic ResultsThe Annals of Thoracic SurgeryVol. 85Issue 3PreviewUse of the free gastroepiploic artery (GEA) graft for coronary revascularization is not very popular because of its tendency to vasospasm. We hypothesize that the cause of free GEA spasm is graft damage caused by an interruption of venous drainage from the graft. To overcome this problem, we anastomosed the accompanied gastroepiploic vein to the right atrial appendage simultaneously with the GEA grafting in the aortocoronary position. We here assess the clinical result and the angiographic patency of the free GEA graft in our method in the late postoperative period. Full-Text PDF

Transplantation of the Free Gastroepiploic Artery Graft for Myocardial Revascularization: Long-Term Clinical and Angiographic Results

Use of the free gastroepiploic artery (GEA) graft for coronary revascularization is not very popular because of its tendency to vasospasm. We hypothesize that the cause of free GEA spasm is graft damage caused by an interruption of venous drainage from the graft. To overcome this problem, we anastomosed the accompanied gastroepiploic vein to the right atrial appendage simultaneously with the GEA grafting in the aortocoronary position. We here assess the clinical result and the angiographic patency of the free GEA graft in our method in the late postoperative period. Between January 1997 and April 2001, 57 patients underwent coronary artery grafting with a free GEA using our method. A total of 169 distal anastomoses (average 2.96) were constructed. The free GEA grafts were anastomosed to the main right coronary artery in 26 patients, right coronary artery branch in 27, left anterior descending artery in 1 patient, high lateral branch in 2 patients, and circumflex branch in 2. The mean clinical follow-up is 77 months (range, 35 to 110) in 57 cases, and the angiographic follow-up averages 77 months (range, 37 to 110) in 46 cases. There was no cardiac death, and all patients were in Canadian Cardiovascular Society class II or less. The mean 77-month patency rate of the free GEA in our method was 95.7%. The patency rates of internal thoracic artery, radial artery, and saphenous vein graft in the same period were respectively 93.2%, 100%, and 81.3%. Free GEA grafting with venous drainage for myocardial revascularization provided excellent long-term performance.

Hemodynamic and functional consequences of radial artery removal for coronary artery bypass grafting

Five years after surgery the echo-Doppler characteristics of the forearm circulation and the transcutaneous oxygen and carbon dioxide pressures of the operated and control arm were determined at rest and under conditions of hand exercise in 34 patients who received a radial artery graft for myocardial revascularization. Doppler measurements showed the ulnar compensation to radial artery removal, and transcutaneous measurements demonstrated a moderate degree of exercise-induced hand ischemia on the operated site.

Midterm clinical and angiographic results of radial artery grafts used for myocardial revascularization

Objective: To evaluate the midterm angiographic results of the use of radial artery grafts for myocardial revascularization. Methods: The first 68 consecutive surviving patients who received a radial artery graft proximally anastomosed to the aorta at our institution were studied again at 5 years (mean 59 ± 6.5 months) of follow-up; 48 of these patients had previously undergone an early angiographic examination. The response of the radial artery to the endovascular infusion of serotonin was evaluated 1 and 5 years after the operation, and the midterm status of the radial artery graft was correlated with the degree of preoperative stenosis of the target vessel and with calcium-channel blocker therapy. Results: The patency and perfect patency rates of the radial artery grafts 5 years after the operation were 91.9% and 87.0%, respectively. All radial artery grafts that were patent early after the operation remained patent at midterm follow-up, and early parietal irregularities in 7 patients were seen to have disappeared after 5 years. The early propensity toward graft spasm after serotonin challenge was markedly decreased at midterm follow-up. The continued use of calcium-channel antagonists after the first postoperative year did not influence the radial artery graft status, whereas the preoperative severity of the target-vessel stenosis markedly influenced the angiographic results. Conclusions: The midterm angiographic results of radial artery grafts used for myocardial revascularization are excellent. The correct surgical indication is essential. Continued therapy with calcium-channel antagonists after the first year does not influence the midterm angiographic results. (J Thorac Cardiovasc Surg 1998;116:1015-21)

Midterm Results of Free Internal Thoracic Artery Grafting for Myocardial Revascularization

Background. This study investigated the midterm results after free internal thoracic artery (FITA) grafting for coronary artery bypass grafting. Methods. Between 1988 and 1995, coronary artery bypass grafting and postoperative graft angiography were performed in 337 patients, of whom 56 patients were treated with 57 FITA grafts. We examined the postoperative graft patency of FITA grafts compared with in situ internal thoracic artery (IITA) grafts, and the late results in the patients receiving at least one FITA graft (FITA group) were compared with those in the patients receiving only IITA graft (IITA group). Results. The early postoperative graft patency rate was 93.2% for the FITA grafts and 96.0% for the IITA grafts (not significant [NS]). Patients underwent sequential graft angiography at 29.5 months postoperatively (25 FITA and 89 IITA). The late graft patency rate was 100% and 92.1%, respectively (not significant). The cardiac death-free survival rate at 5 years was 93.5% in the FITA group and 96.6% in the IITA group (not significant), and the angina-free survival rate at 5 years was 80.6% and 83.2%, respectively (not significant). Conclusions. The FITA provides late results comparable with those attained with IITA.

Experience with Bilateral Internal Mammary Artery Grafts for Myocardial Revascularization in Asian Patients

Bilateral internal mammary artery grafts were used for direct myocardial revascularisation in 72 patients from August 1988 to January 1994. Twenty-five of them had diffuse coronary artery disease. The coronary arteries were small in the majority of patients and 10 patients needed endarterectomy. Two patients died in the hospital. Fifty-nine patients were followed up and the mean time of follow-up was 25 months. One patient died during the follow-up period and another patient developed inferior wall myocardial infarction. Three patients are on antianginal medications and the rest are doing well.

Bovine internal thoracic artery graft for myocardial revascularization: Late results

From May 1988 to March 1990, the bovine internal thoracic artery (ITA) graft, 3 mm in diameter, was used for coronary artery bypass grafting in 29 patients with the approval of the Japanese Ministry of Health. Excluding three postoperative deaths and 6 patients who rejected postoperative angiography, 20 patients (13 men and 7 women; mean age, 62 years; range, 37 to 80 years) were followed up angiographically for up to 4 years. Sites of bovine ITA anastomosis were as follows: anterior descending, 4; circumflex, 5; and right coronary artery, 11. The mean bovine ITA graft blood flow measured by electromagnetic flowmeter was 75.2 mL/min (range, 40 to 150 mL/min). During the mean follow-up of 45 months (range, 30 to 52 months), 12 patients underwent postoperative angiography once, 6 patients twice, and 2 patients three times. It revealed 14 of 16 (88%) bovine ITA grafts were patent within 2 posioperative months. Three of 6 (50%) were patent at 3 to 12 months, of which 2 patent grafts required balloon angioplasty for distal anastomotic stenosis. In 7 patients restudied later than 1 year (20, 24, 25, 44, 48, 50, and 52 months), one of seven grafts (14%) was patent. There was stenosis (≤50%) at four distal and one proximal bovine ITA anastomotic sites, but no focal stenosis was found in the trunk at any period. There was one late death due to renal failure, one myocardial infarction, and one mild angina due to bovine ITA graft failure. The patency rate of concomitantly used autologous grafts was 93% ( 14 / 15 ) in ITA, 100% ( 4 / 4 ) in gastroepiploic artery, and 94% ( 17 / 18 ) in saphenous vein. In conclusion, the bovine ITA graft is not suitable for coronary artery bypass grafting at present because the occlusion rate greatly increases with time.

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.

Anatomical Studies to Support the Expanded Use of the Internal Mammary Artery Graft for Myocardial Revascularization

The internal mammary artery pedicle graft is frequently used for coronary bypass. Five internal mammary artery pedicle grafts, harvested but not utilized for coronary bypass, underwent histological examination. The histological studies demonstrated that the vasa vasorum were confined to the adventitia and did not penetrate the media of the internal mammary artery. These observations indicate that the media is nourished entirely from the lumen and suggest that harvesting the internal mammary artery as a free graft would not subject the wall of the artery to ischemic injury. Subsequent to these studies, we used the right internal mammary artery as a free graft to revascularize the distal circumflex coronary artery in 12 patients. The free graft was anastomosed to marginal branches of the circumflex and was then brought up to the left internal mammary artery pedicle graft and anastomosed end-to-side. This procedure has not resulted in excessive postoperative bleeding or sternal infections, and has relieved the anginal syndrome in all 12 patients.

７０歳以上の高齢者における内胸動脈（ＩＭＡ）を用いた多枝冠動脈バイパス術の検討

７０歳以上の高齢者における内胸動脈（ＩＭＡ）を用いた多枝冠動脈バイパス術の検討