Use of 2 internal mammary arteries in coronary bypass. Combination with a bypass using the gastroepiploic artery in 2 cases

Coronary revascularisation by bilateral internal mammary artery grafting was performed in 39 patients. The left internal mammary was anastomosed to the left anterior descending (N = 22), the left lateral (N = 12) or diagonal artery (N = 5). The right internal mammary was implanted on the right coronary (N = 17), the left anterior descending (N = 16), the left lateral (N = 3) or diagonal artery (N = 3). In two cases, the inferior myocardial segments were revascularised by grafting the gastroepiploic artery. Three patients died and one patient had signs of postoperative myocardial infarction. Respiratory complications, usually mild, occurred in 5 patients. Bilateral internal mammary artery grafting should be reserved for: 1) young patients, 2) those without usable leg veins (varicose veins, previous stripping or coronary bypass surgery). The gastroepiploic artery is a useful arterial graft for revascularizing regions of the heart inaccessible to the internal mammary arteries.     

Pedicled right internal mammary artery for reoperative off-pump revascularization of left anterior descending coronary artery

In situ right internal mammary artery is the graft of choice in reoperative off-pump coronary artery bypass grafting, as well as in primary on-pump coronary artery bypass grafting, unless the vessel has been used previously. However, there are not enough data about postoperative angiographic findings of the in situ right internal mammary artery in reoperative coronary artery bypass grafting with the off-pump technique. From September 1993 through January 2004, we reviewed the postoperative course and the graft patency of 12 selected patients who underwent off-pump coronary artery bypass grafting reoperation only for revascularization of the left anterior descending artery, by means of a pedicled right internal mammary artery graft. All patients were evaluated clinically and by postoperative coronary angiography. There were no early or late deaths during the mean follow-up period of 33.08 +/- 30.05 months (range, 1-77 months). The mean interval from the 1st operation to the 2nd operation was 74.1 +/- 57.01 months (range, 4.5-171 months). Postoperative coronary angiograms of all patients showed a 100% patency rate for both in situ grafts and composite grafts. We suggest that use of the in situ right internal mammary artery in off-pump coronary artery bypass grafting is a safe and reliable option for revascularizing the left anterior descending artery, especially in reoperation.     

Coronary flow reserve provided by sequential internal mammary artery grafts

Although internal mammary artery bypass grafts have a high patency rate, the adequacy of blood flow through such conduits, particularly if used sequentially, has been questioned. To evaluate this issue, coronary flow reserve was studied in 20 patients after coronary bypass surgery. Nine patients had sequential internal mammary grafts to the diagonal and left anterior descending coronary arteries; five had a single internal mammary graft to the left anterior descending artery and six had sequential saphenous vein grafts. Fifteen additional single vein grafts were also placed in these patients. Coronary flow reserve was measured after contrast-induced hyperemia by a digital subtraction angiographic technique an average of 25 days after surgery. There was no difference in coronary flow reserve between the proximal and distal anastomotic regions in either the sequential internal mammary graft group (2.14 +/- 0.50 versus 2.29 +/- 0.68, n = 8, p = NS) or the sequential vein group (1.77 +/- 0.49 versus 2.08 +/- 0.78, n = 6, p = NS). In addition, the flow reserve provided to either vascular bed of the sequential internal mammary graft was not different from that provided by a single internal mammary graft (1.64 +/- 0.39, n = 5), a single vein graft (1.95 +/- 0.95, n = 15) or nonstenotic native coronary arteries (2.04 +/- 0.87, n = 34). No cases of intracoronary steal were observed. Although some patients had unequal flow reserves between the proximal and distal anastomotic zones, these occurred in the setting of residual coronary stenoses distal to the site of graft insertion or prior myocardial infarction in the grafted distribution.(ABSTRACT TRUNCATED AT 250 WORDS)     

10-year results of anastomoses of the left internal mammary artery to the anterior interventricular artery. Angiographic and radionuclide controls

The long term patency of left internal mammary artery graft is better than that of saphenous vein graft. The aim of this study was to determined if this high patency rate was accompanied by a satisfactory myocardial perfusion. Among 143 patients treated with an internal mammary artery graft on the left anterior descending artery between 1972 and 1976, 42 patients underwent coronary angiogram and exercise tomoscintigraphy (thallium 201) over 10 years after surgery. The left internal mammary artery was patent in 92% without any atheromatous lesions. The myocardial perfusion in the area supplied by the left anterior descending artery was normal in 74%. A slight ischemia appeared during exercise in 19% without any clinical symptoms. This long term study shows excellent anatomical results correlated with a good myocardial perfusion during exercise in most cases.     

Myocardial revascularization with the gastroepiploic artery. The initial experience

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 April 1990 we have implanted this artery in 33 cases (32 in situ and one free grafts). The pedicled grafts were implanted in 17 patients in the main right coronary artery, in 13 we grafted the right distal branches, in one the left anterior descending, and the circumflex branch in one. The free graft was implanted in the first diagonal. Mean grafts per patient was of three in this series, with a mean of 2 arterial grafts per patient. One patient died in the early postoperative period. The remaining patients had an uncomplicated postoperative period. 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.     

Coronary artery bypass grafting by utilizing the internal mammary artery graft in 100 Japanese patients

The internal mammary artery (IMA) grafting for myocardial revascularization was performed in 100 Japanese patients during a three-year period. There were 86 males and 14 females with the mean age of 58 +/- 9 (37 approximately 75 year-old). Unilateral IMA was used in 88 patients and bilateral IMA was used in 12 patients. Sequential IMA grafting was performed in 5 patients. The sites of IMA grafting were 91 left anterior descending arteries (LAD), 16 diagonal branches, 8 circumflex arteries and 2 right coronary arteries. Saphenous vein or gastroepiploic artery was concomitantly used to bypass the other coronary arteries in 90 patients. The number of distal anastomosis ranged from 1 to 6 and the mean was 2.8 per patient. Two patients died within 30 days and one patient died at 3 months after surgery. Perioperative myocardial infarction was noted in 3 patients. Symptomatic relief was obtained in 94 (97%) of 97 survivors. The patency of the IMA graft at mean 2.2 postoperative months was 97% (58/60) in LAD, 100% (14/14) in the diagonal branch, 100% (5/5) in the circumflex artery, 100% (1/1) in the right coronary artery, and 98% (78/80) in over-all grafted coronary arteries. Pre- and postoperative exercise thallium scintigraphy in 13 patients, who received the IMA graft to severely stenosed LAD, showed significant improvement of the washout ratio (from 33.1 +/- 16.9% to 47.4 +/- 14.8%) which was nearly equivalent to that of the saphenous vein graft to LAD (from 24.8 +/- 6.2% to 48.1 +/- 6.6%, n = 7).(ABSTRACT TRUNCATED AT 250 WORDS)     

Sequential internal mammary artery bypass for multiple coronary stenoses

Long-term studies (10 years) show a 50 per cent patency rate of saphenous vein autograft and 95 per cent patency rate of internal mammary artery coronary bypass grafts. In some situations (after saphenous vein stripping, varicose and fibrotic veins) it is not possible to use venous grafts and the internal mammary artery has to be used. However, the internal mammary artery is usually only used for revascularisation of the left anterior descending artery. Sequential internal mammary artery bypass is a technique which can be used for revascularizing the left anterior descending artery. Seven men aged 44 to 68 years (average 55 years) were operated between November 1983 and February 1985. These patients had clinically stable (4 cases) or instable (3 cases) angina. Two patients had previously undergone bilateral saphenous vein stripping and one patient a terminal anastomosis on the left anterior descending and a latero-lateral anastomosis on the diagonal artery. Three patients had an associated venous bypass graft and one patient also underwent aortic valve replacement. There were no cases of postoperative myocardial infarction. Five control angiographies were carried out during the first postoperative month. In 4 patients the internal mammary graft ant the latero-lateral and termino-lateral anastomoses were patent. In the other case, the latero-lateral anastomosis and the diagonal artery was occluded but the internal mammary graft and the termino-lateral anastomosis on the left anterior descending artery were patent. The average follow-up period is now 18 months: there have been no recurrences of chest pain or any ECG changes. These results show that internal mammary artery bypass grafting is a delicate procedure.(ABSTRACT TRUNCATED AT 250 WORDS)     

Late patency of recycled internal mammary artery: verification by Doppler echocardiography and coronary angiography

We report the case of a 57-year-old man who had presented with exertional angina early in 1997 and had subsequently undergone myocardial revascularization with the use of both internal mammary arteries. Two months after surgery, the patient was readmitted to the hospital with unstable angina. Coronary angiography revealed a 90% occlusion of the left internal mammary artery anastomosis, which was attached to the left anterior descending coronary artery. At reoperation, the left internal mammary artery was detached from the left anterior descending coronary artery, probed and injected with papaverine, checked for patency, and regrafted to the same coronary artery. Recycling of the left internal mammary artery was facilitated by the harvesting and routing technique that had been used during the previous operation. At the patient's 1-year follow-up visit, both Doppler echocardiography and coronary angiography showed patency of the recycled graft. We conclude that recycling of the left internal mammary artery is a safe and effective option in selected patients who require reoperation after myocardial revascularization.     

Mid-to-long-term patency comparison of the right internal thoracic artery grafts on the left anterior descending and on the right coronary arteries

BACKGROUND: The excellent results obtained from internal thoracic artery for myocardial revascularization have led surgeons to simultaneous use of other arterial conduits, particularly the right internal thoracic artery. However, some controversy still exists regarding the optimal target coronary artery for this graft; different strategies have been proposed for bilateral internal thoracic artery grafting. PATIENTS AND METHODS: 59 patients with right internal thoracic artery grafts were monitored using coronary arteriography in order to compare the patency of this graft on the left anterior descending and the right coronary arteries. The right internal thoracic artery was grafted to left anterior descending artery in 39 patients (group 1) and to right coronary artery in 20 patients (group 2). RESULTS: The mean period of follow-up was 64.07 months (range: 37 to 185 months). Overall, 8 of the 59 grafts (13.6%) were occluded at the arteriography. In group 1, 1 of 39 (2.6%) grafts and in group 2, 7 of 20 (35%) grafts are found to be occluded. These results are considered statistically significant (p < 0.001). COMMENT: The results show that the patency of the right internal thoracic artery is significantly better on the left anterior descending artery than on the right coronary artery in the mid-to-long term, and patency does not differ from the left internal thoracic artery on the left anterior descending artery.     

Assessment of coronary bypass graft patency by electron-beam computed tomography

Twenty-one patients undergoing coronary artery bypass grafting were prospectively evaluated by conventional selective coronary angiography and electron-beam computed tomography. Eighty bypass grafts (60 saphenous vein and 20 left or right internal mammary artery) were evaluated for patency. The sensitivity and specificity of electron-beam computed tomography were 72% and 100%, respectively; positive and negative predictive values were 100% and 92.5%, respectively. Sensitivity and specificity according to coronary region were: left anterior descending artery, 33% and 100%; diagonal artery, 67% and 100%; circumflex artery, 75% and 100%; right coronary artery, 100% and 100%. Electron-beam computed tomography is relatively accurate and a promising tool for noninvasive evaluation of graft patency after coronary artery bypass graft surgery.     

Early postoperative occlusion of a left internal mammary artery bypass graft with subsequent restoration of patency.

Total occlusion of a left internal mammary artery (LIMA) bypass graft is a rare complication, and reversal of a documented occlusion has not been reported. This is a case of an early postoperative occlusion of a LIMA graft that was found to be patent 4 months later. A patient with three vessel disease (including a moderate lesion in the proximal left anterior descending artery and a severe lesion in its mid-portion) underwent coronary artery bypass grafting with a LIMA to the mid-left anterior descending artery (LAD) and saphenous vein grafts to the right coronary and left circumflex arteries. Coronary angiography 3 months after surgery revealed a totally occluded internal mammary artery and saphenous vein grafts. The patient then underwent a successful angioplasty of the more distal lesion in the LAD. She subsequently returned with recurrent angina. Repeat coronary angiography revealed rapid progression of the disease in the proximal LAD with the more distal angioplasty site being widely patent. Selective arteriography of the internal mammary artery at that time revealed a patent vessel. Thus, the internal mammary graft is a physiologically active conduit that is dependent on flow dynamics. Competitive flow through the nonobstructive native LAD in combination with impedance of flow through the internal mammary artery due to a severe lesion in the LAD distal to the anastomosis led to a functionally occluded LIMA. When the obstruction in the proximal LAD progressed and the distal obstruction was successfully angioplastied, the flow dynamics in the internal mammary improved, allowing for its dilatation and restoration of patency.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparison of coronary hemodynamics in patients with internal mammary artery and saphenous vein coronary artery bypass grafts: a noninvasive approach using combined two-dimensional and Doppler echocardiography

Blood flow in bypass grafts and recipient left anterior descending coronary arteries was evaluated with combined two-dimensional and Doppler echocardiography in 15 patients with an internal mammary artery graft and in 24 patients with a saphenous vein graft. Comparative studies of coronary hemodynamics were also performed regarding these two different grafting techniques. The graft vessel was detected in 11 (79%) of 14 patients with an internal mammary artery graft and in 20 (87%) of 23 with a saphenous vein graft. The recipient left anterior descending coronary artery was detected in 10 (67%) of the former group and 17 (71%) of the latter. The blood flow patterns obtained were generally biphasic, consisting of systolic and diastolic phases with higher velocity during diastole. The maximal diastolic flow velocity in internal mammary artery grafts was much higher than that in saphenous vein grafts. In patients with an internal mammary artery graft, the flow pattern characteristics within the recipient coronary artery were quite similar to those within the arterial graft, and flow velocities within the recipient coronary artery and the arterial graft were quantitatively almost identical. This outcome may contribute to the long-term patency seen in internal mammary artery grafts. On the other hand, the flow velocity in saphenous vein grafts was fairly low throughout the cardiac cycle. Flow velocity in the recipient coronary artery in patients with a saphenous vein graft was accelerated only in early diastole. As a result, the recipient coronary artery flow pattern and velocity differed substantially from those in the saphenous vein graft.(ABSTRACT TRUNCATED AT 250 WORDS)     

Robotically enhanced coronary artery bypass surgery

BACKGROUND: Robotically enhanced telemanipulation surgery is a fast developing technique which allows totally endoscopic cardiac surgery with utmost precision and perfection on both beating heart as well as arrested heart. METHODS AND RESULTS: Between December 2002 and February 2004, 125 patients underwent robotically enhanced coronary artery bypass surgery using the da Vinci telemanipulation system (Intuitive Surgical Inc., California). Eleven patients underwent totally endoscopic coronary artery bypass surgery. Of them 9 were done on beating heart while 2 were done on arrested heart. One hundred and fourteen patients had endoscopic takedown of internal mammary artery followed by minimally invasive direct coronary artery bypass in 63 patients and left anterolateral thoracotomy in 51 patients. The internal mammary artery mobilization time was 42 min (35-74 min) while the left internal mammary artery to left anterior descending artery anastomosis time ranged from 20 to 36 min for the totally endoscopic coronary artery bypass patients. In 1 patient, the right internal mammary artery was anastomosed to diagonal artery totally endoscopically. The mean internal mammary artery flow by Doppler measurement done in patients undergoing minimally invasive direct coronary artery bypass was 64 ml/min. Seven patients required conversion to median sternotomy and coronary bypass surgery on beating heart. The mean intensive care unit stay was 1.2 days and the mean hospital stay 4.5 days. There was 1 in-hospital mortality. All 11 patients who underwent totally endoscopic bypass surgery had coronary angiography done at 3 months interval which showed 100% patency in 10 patients while one patient had 50% anastomotic narrowing for which coronary angioplasty was done in the same sitting. CONCLUSIONS: Using telematic technology, a complete endoscopic anastomosis is possible in both single vessel and suitable double vessel disease patients. The use of robotics is now extended to achieve complete myocardial revascularization by harvesting both the internal mammary arteries and making a small thoracotomy for direct anastomosis as well.     

Off-pump bypass surgery: the early experience, 1969-1985

This is a review of 733 patients who underwent off-pump bypass surgery of the right coronary artery and left anterior descending coronary artery between 1969 and 1985. Two hundred sixty-four patients underwent single bypass of the left anterior descending coronary artery, and 79 patients underwent single bypass of the right coronary artery. Both the left anterior descending and right coronary arteries were bypassed in 390 patients. In contrast to the present-day use of mechanical devices to stabilize the target vessel, a 4-suture surgical technique was used for this purpose. This technique, which we illustrate, proved less cumbersome and made the graft anastomosis easy to perform. Our early experience (1969 through 1972) in operating on 199 patients resulted in an operative mortality rate of 4.5% (9/199). From 1973 through 1985, improved patient selection and use of the left internal thoracic artery as the conduit of choice for bypass of the left anterior descending coronary artery reduced the operative mortality rate for 534 patients to 1.3% (7/534). Routine postoperative angiograms were not performed; therefore, the graft patency rate is not available. However, an ongoing 34-year follow-up study of the 264 patients who underwent a single left anterior descending bypass showed the saphenous vein graft to be open in 64.3% (18/28) patients and the left internal thoracic graft in 92.2% (59/64) of patients studied. Seventy-four of the 264 patients in this study were still alive in 2003.     

Early postoperative occlusion of a left internal mammary artery bypass graft with subsequent restoration of patency

Total occlusion of a left internal mammary artery (LIMA) bypass graft is a rare complication, and reversal of a documented occlusion has not been reported. This is a case of an early postoperative occlusion of a LIMA graft that was found to be patent 4 months later. A patient with three vessel disease (including a moderate lesion in the proximal left anterior descending artery and a severe lesion in its mid-portion) underwent coronary artery bypass grafting with a LIMA to the mid-left anterior descending artery (LAD) and saphenous vein grafts to the right coronary and left circumflex arteries. Coronary angiography 3 months after surgery revealed a totally occluded internal mammary artery and saphenous vein grafts. The patient then underwent a successful angioplasty of the more distal lesion in the LAD. She subsequently returned with recurrent angina. Repeat coronary angiography revealed rapid progression of the disease in the proximal LAD with the more distal angioplasty site being widely patent. Selective arteriography of the internal mammary artery at that time revealed a patent vessel. Thus, the internal mammary graft is a physiologically active conduit that is dependent on flow dynamics. Competitive flow through the nonobstructive native LAD in combination with impedance of flow through the internal mammary artery due to a severe lesion in the LAD distal to the anastomosis led to a functionally occluded LIMA. When the obstruction in the proximal LAD progressed and the distal obstruction was successfully angioplastied, the flow dynamics in the internal mammary improved, allowing for its dilatation and restoration of patency. Therefore, an angiographically occluded internal mammary graft may be only functionally occluded and reversible even when the occlusion is demonstrated several days apart.     

A single coronary artery from the right sinus of valsalva associated with atherosclerosis

Anomalous origin of the main coronary arteries from the aorta is rare. We report a case with a single coronary artery from the right sinus of Valsalva associated with atherosclerosis.The patient was treated with a coronary artery bypass procedure: left internal mammary artery (LIMA) to the left anterior descending artery (LAD), right internal mammary artery (RIMA) to the right coronary artery (RCA).The postoperative course was uneventful.     

Use of stents to treat kinks causing obstruction in a left internal mammary artery graft

Left internal mammary arteries (LIMA) are used routinely as grafts to the left anterior descending coronary artery (LAD) in selected patients undergoing coronary artery bypass graft (CABG) surgery because of better long-term patency rates. Pathology other than fibrointimal hyperplasia, accelerated atherosclerosis, or thrombus can sometimes cause obstructive lesions in such grafts. This report illustrates a kink in a LIMA graft to the LAD causing an obstructive lesion shortly after surgery and describes the subsequent management of this lesion with intracoronary stents. Cathet. Cardiovasc. Intervent. 46:223–226, 1999. © 1999 Wiley-Liss, Inc.     

Effects of previously well-developed collateral vessels on left internal mammary artery graft flow after bypass surgery

Transthoracic Doppler ultrasonography can assess left internal mammary artery patency and flow after coronary artery bypass grafting. We aimed to show, by transthoracic Doppler ultrasonography, the early effects upon left internal mammary artery graft flow of preoperative collateral vessels supplying the left anterior descending artery. Thirty-four consecutive patients undergoing coronary artery bypass were prospectively enrolled: 19 patients with collateral vessels supplying the left anterior descending were compared with 15 patients without collaterals. After bypass, end-diastolic velocity, mean velocity, flow volume, and ejection fraction were significantly greater, and the resistivity index was lower in patients with collateral vessels. The changes in velocities, volume, resistivity index, and pulsatility index were also found to be greater in patients with collateral vessels than in those without collaterals. Collateral vessels were the only factor affecting the changes in end-diastolic volume, mean velocity, flow volume, and resistivity index in multivariate analysis. Three factors affected postoperative left ventricular ejection fraction: collateral vessels, preoperative ejection fraction, and changes in left internal mammary flow volume. We conclude that patients with well-developed collaterals to the left anterior descending have better flow in the left internal mammary graft and more significant improvement in left ventricular function after coronary bypass. The flow volume of the mammary graft and the improvement of ventricular systolic functions after coronary bypass might be presumed with the presence of grade 2 or 3 preoperative collateral vessels.     

Internal mammary artery steal syndrome secondary to an anomalous lateral branch

A 53-year-old male who underwent three-vessel coronary artery bypass grafting had a left internal mammary artery (LIMA) graft to the left anterior descending artery (LAD) and saphenous venous grafts to right coronary artery (RCA) and left circumflex coronary artery. Four years after surgery, he developed exertion angina associated with upper body exercises and even deep breathing at times. Angiographic evaluation revealed an anomalous lateral internal thoracic artery with steal phenomenon documented by adenosine cardiolyte. Patient was successfully treated with transcutaneous steel coil embolization by closing the anomalous vessel. Repeat stress electrocardiogram did not show any signs of ischemia. This case report emphasizes the variability in internal mammary artery (IMA) anatomy and the need to completely ligate all the branches of internal mammary artery intraoperatively.     

Systolic compression of bypass grafts

Myocardial bridging, systolic compression of an intramyocardial segment of an epicardial coronary artery, is well known to involve native coronary arteries. Systolic compression of bypass grafts has been rarely described. We present two cases of dynamic systolic compression of bypass grafts to native coronary arteries: one of a vein graft to the right coronary artery, and another of a left internal mammary artery to the left anterior descending artery.