Anastomosis Of Internal Mammary Artery Research Articles

Important Anatomical and Physiological Considerations in Performance of Complex Mammary–Coronary Artery Operations

One or more internal mammary artery (IMA) anastomoses were performed in 87% of 692 consecutive coronary artery bypass operations performed over a 20-month period. One IMA was used in 68% (N = 469) and both IMAs were used in 19% (N = 130). Only saphenous vein grafts were used in 13% (N = 93). The mean number of anastomoses (all types) was 3.5. Fifty-seven patients were having a reoperation; bilateral IMA grafting was performed in 23% (N = 13). In 60 patients, 3 or more IMA anastomoses were performed: 3 IMA anastomoses, 50 patients; 4, 9 patients; and 5, 1 patient. In 27 patients, repeat coronary arteriography was performed within 30 days of operation to evaluate dynamics of IMA, saphenous vein, and native coronary artery flow. Major flow or all flow was through the graft (vs. the native coronary artery) in 62% of in situ IMA bypass grafts, 86% of free IMA grafts and 94% of saphenous vein grafts. Hospital mortality excluding patients having reoperation was 1.7% (11/635); it was less than 1% for patients having either single IMA grafting procedures (4/437) or bilateral IMA grafting procedures (1/117). Hospital mortality for patients receiving only saphenous vein grafts was surprisingly high, 7.4% (6/81). Major determinants of flow through the in situ IMA sequential graft are the size and flow of the IMA, the degree of proximal native coronary artery narrowing, the distally grafted to proximally grafted coronary artery size ratio, and probably the size of the side-to-side anastomosis. Technical factors important for multiple IMA grafts are the length and diameter of the IMA, use of the diamond anastomosis, absence of coronary artery disease at side-to-side anastomoses, epicardial location of the coronary artery, and no angulation distal to the sites of sequential anastomoses. Unless ideal conditions of IMA flow and size are met, an IMA graft supplying more than two coronary arteries might better be done with a free IMA graft.

Use of the mammary artery in coronary revascularization

From August 1983 through December 1985 1088 patients underwent coronary surgery. 406 (37%) received a single or bilateral internal mammary artery (IMA) graft with single or sequential anastomoses. The youngest patient was 6 years old, the oldest 75, with a mean age of 55.7 years. A total of 672 IMA anastomoses was constructed. In addition 348 patients received 610 saphenous vein grafts. 83% of the IMA were anastomosed to the LAD and its branches, 12% to the circumflex and 5% to the right coronary artery. 4 patients (0.98%) died postoperatively, 402 survived and are free of angina. In our experience the IMA can be used routinely with low operative risk and good results.

Flow capacity of the canine internal mammary artery

The internal mammary artery has excellent long-term patency when used as a conduit for coronary artery bypass, and clinical and experimental studies have shown that blood flow through an internal mammary artery graft is satisfactory for most coronary artery branches. Multiple distal anastomoses from a single internal mammary artery, either with sequential anastomoses or with a Y-graft, might require additional blood flow through the vessel, and there has been concern that the flow capacity of the internal mammary artery is insufficient with these techniques. To better define the immediate postoperative flow capacity and pattern of the internal mammary artery, we performed experiments in seven dogs in which the left internal mammary artery was anastomosed to the circumflex coronary artery. In situ, blood flow in the internal mammary artery was 27 ml/min. Blood flow was 63 ml/min in the circumflex coronary artery and 42 ml/min in the left anterior descending coronary artery. After anastomosis of the left internal mammary artery to the circumflex coronary artery, the left main coronary artery was ligated; flow through the bypass graft increased to 92 ml/min, and systemic hemodynamics remained stable. Isoproterenol stimulation further increased flow through the left internal mammary artery graft to 160 ml/min. This study suggests that the canine internal mammary artery is capable of substantial early increase in flow and can, in fact, support the entire left coronary circulation.

Twelve-year experience with internal mammary artery for coronary artery bypass

From Feb. 1, 1972, to Jan. 30, 1984, 1,000 patients had isolated coronary bypass with at least one internal mammary artery, and 103 of them had bilateral internal mammary artery grafts. There were 1,395 associated vein grafts and 1,158 internal mammary artery anastomoses, for a total of 2,556 grafts (2.5 per patient). Patients were followed up for 1 to 12 years (mean 6.3 years) and 77 patients were lost to follow-up at a mean of 4.0 years. Operative mortality was 1.4%, with 11 of 14 deaths in the first 240 patients (4.6%) and eight of 14 in the 103 patients with bilateral internal mammary artery grafts. There were 93 late deaths, with an actuarial survival rate of 93% at 5 years and 84% at 10 years. Angina occurred at a mean rate of 6.2% +/- 1.2% per year. Perioperative infarction was detected in 37 patients (3.7%). Late infarction occurred in 75 patients, for a mean rate of 1.5% +/- 0.3% per year. Reoperation (or percutaneous transluminal coronary angioplasty) was necessary in 35 patients, for a mean rate of 0.85% +/- 0.28% per year. Graft patency was assessed by 1,029 follow-up catheterizations in 519 patients. The patency rate of the left internal mammary artery was 96.4% at 1 year, 88.1% at 5 years, and 88.1% at 10 years. That of the right internal mammary artery was 92.8% (p = NS) at 1 year, 84.6% (p = NS) at 5 years, and at 10 years the numbers were too small to be meaningful. Comparison of patency rates for all internal mammary artery grafts with vein grafts gave 1 year graft patency rates of 95.7% versus 93.4% (p less than 0.025), 5 year rates of 87.9% versus 74.0% (p less than 0.001), and 10 year rates of 83.0% versus 41.0% (p less than 0.001). Included in these patency data are 20 free internal mammary artery grafts; 16 were studied (mean 2.3 years) and 12 of these 16 (75%) were patent. Of the 58 sequential internal mammary artery grafts, 18 were studied by catheterization (mean interval 2.0 years); 35 of 36 anastomoses were patent and one end-to-side anastomosis was closed. Morbidity and mortality for patients having internal mammary artery grafting are comparable to those of patients having saphenous vein bypass only. The demonstrated superior patency for internal mammary artery grafts supports the routine use of bilateral internal mammary artery grafting.

Sequential internal mammary artery grafts: Expanded utilization of an ideal conduit

The internal mammary artery, when used as a conduit for coronary artery bypass, offers a better long-term patency rate and survival rate than the saphenous vein; however, its utility has been limited. Among other factors, the availability of only two internal mammary arteries for anastomosis has been a major limitation. In an attempt to overcome this limitation, we constructed sequential internal mammary artery grafts in 87 patients. In 49 patients (Group I), only one internal mammary artery was used for sequential anastomosis. In another 31 patients (Group II), one internal mammary artery was used for sequential anastomosis and the other was used for single end-to-side anastomosis. Both internal mammary arteries were used in seven patients (Group III) for the construction of sequential anastomoses. Postoperatively, 64 patients were evaluated by exercise stress tests. None of these patients had a positive stress test although seven patients (11%) had electrocardiographic changes that were considered equivocal. Coronary angiography was performed in 35 of the 87 patients, with 92 vein grafts and 90 internal mammary artery anastomotic sites evaluated within 1 year of operation. A total of 83 vein grafts and 84 internal mammary artery anastomotic sites evaluated within 1 year of operation. A total of 83 vein grafts and 84 internal mammary artery anastomoses were found to be patent. Thus the patency rate for vein grafts was 90% and for internal mammary artery grafts, 93%. During the follow-up period (8 to 52 months), three patients died and one was lost to follow-up. Among the remaining patients, 79 had complete relief from symptoms, three had minimal symptoms, and one patient obtained no relief from symptoms. Based on these results, we have concluded that the extended use of internal mammary artery, constructing sequential anastomoses, is technically feasible and provides adequate perfusion to the area of myocardium supplied by such grafts.

A Technique of Anastomosis of the Right Internal Mammary Artery to the Circumflex Artery and Its Branches

A new technique for direct revascularization of the left circumflex artery and its ventricular branches through anastomosis with the right internal mammary artery (RIMA) was applied in 56 patients. Postoperative angiographic studies in 17 patients showed that positioned behind the aorta, the RIMA can reach the circumflex artery with no tension, allowing adequate distal filling.

Sequential internal mammary artery (IMA) grafts in coronary artery bypass surgery.

Since 1972, double or triple left IMA bypasses have been made on 61 consecutive patients with a total of 123 distal anastomoses to the LAD or to the LD branches of the LAD. There were 54 additional vein grafts with 102 distal anastomoses. The number of single IMA grafts in the same period of time was 400. Hospital mortality was 2 patients (3.3%), with a late mortality of 7 patients (11.3%), 2 of them being heart-related, one of hypernephroma, one suicide, and of unknown cause in the remaining 3 patients. Five patients refused postoperative angiography. There were 50 patients with one or more postoperative angiograms available for the analysis after a mean follow-up time of 35.1 (0.5 to 128) months. The late patency of the left IMA anastomoses was 97% (98/101) and 82.4% (84/102) of the vein anastomoses. There were 2 anastomotic left IMA occlusions to the LD at 2 weeks and 10 months, respectively, and to LAD at 13 months. No left IMA graft had become completely occluded. According to the trend analysis, there was a 97.5% patency at 5 years, and 95.7% at 10 years with left IMA grafts compared to 78.4 and 67.9, respectively, with vein grafts. Ten left IMA grafts were dilated, 2 narrowed and 36 unchanged at the late angiography. Sequential left IMA graft, in appropriate cases seems to result in the most superior patency rate of all types of grafts.

Internal mammary artery-coronary artery anastomosis: Influence of the side branches on surgical result

Five of 20 (25%) symptomatic patients with internal mammary artery (IMA) grafts were found to have unusually enlarged side branches on arteriographic studies. One had a large lateral costal branch and four had large pericardial branches with collaterals draining into the pulmonary circulation. In these patients there was significant reduction (mean 44% +/- 3%) in the lumen of the distal IMA compared to its proximal part, with poor filling of the grafted coronary artery. This appeared to be the only cause of anginal symptoms in three of these five patients. The other 15 patients (75%) with small or no side branches had little or no reduction (mean 10% +/- 2%) of the distal IMA lumen. There was good coronary filling in these cases. The enlargement of the side branches indicates large flow in these branches with consequent reduction of flow in the grafted coronary artery. The marked reduction of the distal IMA lumen is a useful sign of reduced graft flow. This phenomenon may be one of the causes of poor results following IMA grafting.

Internal Mammary Artery-Saphenous Vein Composite Conduit: An Alternative for the Proximal Coronary Anastomosis

A patient who had previously undergone saphenous vein bypass grafting was seen with recurrent angina requiring reoperation. At the second operation, technical problems with the ascending aorta ultimately excluded its use for the proximal anastomosis for the second of two bypass grafts. Anastomosis of the left internal mammary artery to the proximal end of the saphenous vein graft successfully resolved the problem.

Technique for performance of internal mammary artery-coronary artery anastomosis

Technique for performance of internal mammary artery-coronary artery anastomosis

Reappearance of anterior QRS forces after coronary bypass surgery: An electrovectorcardiographic study

This report describes the reappearance of anterior QRS electrical forces in six patients after direct coronary arterial bypass surgery. Each patient had severe coronary artery disease including a segmental stenosis of the left anterior descending artery. Revascularization was performed by direct anastomosis of the left Internal mammary artery to the left anterior descending coronary artery and saphenous vein bypass of other stenotic coronary arteries. Preoperative electrocardiograms and vectorcardiograms showed patterns of anterior wall myocardial infarction with absent or diminutive anterior QRS forces. In each case, postoperative studies demonstrated the regeneration of anterior QRS forces within 10 days of operation. Although these patients represent a small percent of those with a preoperative pattern of infarction who undergo coronary revascularization, the findings demonstrate that electrically silent areas of myocardium may be altered and are not always synonymous with myocardial cell death. Chronic myocardial ischemia may in certain instances produce electrocardiographic and vectorcardiographic patterns of myocardial infarction that may be reversible upon reestablishment of perfusion to ischemie areas.

The surgical treatment of unstable angina pectoris.

Since the advent of saphenous vein bypass grafting as successful means of myocardial revascularization, a variety of coronary artery disease syndrome have come under surgical attack. The proper role of surgery in many of these coronary syndromes remains ill-defined. However, clear indications for surgical revascularization exist in patients with unstable angina pectoris, i.e., progressive angina and onset of rest pain and noctural angina in spite of adequate medical therapy. An analysis has been made of 100 consecutive patients with unstable angina pectoris who underwent myocardial revascularization over the past 2 years at the Woodruff Medical Center of Emory University. Included in this group are the following subgroups: 1) Emergency cases with pre-infarction angina (including Printzmetal angina); 2) Cases of combined valvular heart disease and coronary artery disease; and 3) Advanced coronary artery disease with certain complications of previous myocardial infarction. A discussion of the relative merits of saphenous vein grafts and internal mammary artery anastomoses is presented and indicates that the technique selected should be determined by the quality of the distal native coronary circulation. Surgical mortality and morbidity figures, patency rates of saphenous vein grafts and internal mammary artery anastomoses visualized postoperatively, and the number of patients wiht dramatic relief of angina pectoris in this series support current enthusiasms for available surgical techniques for myocardial revascularization.

The Importance of Aortic Arch or Subclavian Angiography Before Coronary Reconstruction

We report a patient with marked atherosclerotic stenosis in the left subclavian artery and a previous anastomosis of the left internal mammary artery to the anterior descending branch of the left coronary artery. The importance of the aortic arch or subclavian angiography before reconstructive operation is discussed.

Direct anastomosis of the bilateral internal mammary artery to the distal coronary artery, without a magnifier, for severe diffuse coronary atherosclerosis.

Forty-three cases of direct anastomosis of unilateral or bilateral internal mammary artery (IMA) and distal coronary artery (DCA), with or without saphenous vein graft (SVG), for severe, diffuse, ischemic coronary artery disease are reported. The technique of anastomosis of IMA and DCA without a magnifier or microscope is discussed in detail. The operative mortality was less than 5% (2 of 43 patients). The initial patency rate of IMA and DCA anastomosis was 97% (34 of 35). Only 8 patients have been restudied 4 to 16 months after surgery. Flow through the IMA ranged from 30 to 60 cc/min, averaging 45 cc/min at the time of surgery. Postoperative ventricular function studies suggest an increase of left ventricular emptying and endocardial fiber-short-ening rate in those with well-functioning grafts. The significant advantage of this technique is that it extends the indications for direct coronary artery reconstruction by anastomosing bilateral IMA to DCA near the apex, where the size of the artery is 1 to 1.5 mm and the SVG is more likely to occlude because of the size discrepancy and expected relatively low blood flow.

Functional evaluation of an internal mammary coronary artery anastomosis

Functional evaluation of an internal mammary coronary artery anastomosis