Emergency myocardial revascularization in acute evolving myocardial infarct

Immediate coronary artery bypass for acute evolving myocardial infarction could be the elective therapy if provided on useful time, because myocardial salvage can be achieved by early reperfusion. Thirty eight patients had emergency coronary artery by-pass graft for acute evolving myocardial infarction during the early phase: 35 were male, the mean age was 51 years (34 to 74). The mean interval between the onset of symptoms and surgery in this series of patients was two hours and a half. This interval seems to be also the time limit in our experience to get a partial or complete recovery of ischemic area. Four patients died in hospital, but they were in severe cardiogenic shock before emergency surgery. Twenty nine cases were free of symptoms at a mean follow-up of 18 months (6 to 36) and two suffered for residual angina. Three patients died after discharge few months later: two during redo emergency vein grafts operations, one in deep left ventricular failure, while he was waiting for heart transplant. All these patients operated on as emergency developed acute myocardial infarction during their stay in hospital waiting for catheter study, surgical operation or during percutaneous transluminal coronary angioplasty. Saphenous vein grafts, were used in twenty nine patients, left internal mammary artery in nine cases, single in four and associated to saphenous vein in five, with an average number of anastomoses of 2.6 (1 to 6) for patient. ECG was found to be normal in 76% of the patients operated on within two hours and a half from the beginning of symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)     

冠状动脉搭桥围术期急性心肌梗死紧急再搭桥

目的：回顾性分析冠状动脉搭桥围术期急性心肌梗死急诊再搭桥的临床经验。方法：在510例冠状动脉搭桥患中，5例患在术后4h内因急性心肌梗死需急诊再搭桥，发生率0．98％。5例患中，男女比例为4：1，年龄56－77岁（平均63．6岁），均为冠状动脉三支血管病变（3例伴左主干病变），手术中搭桥3－5支（人均搭桥3．6支），左乳内动脉桥5根，其余为大隐静脉桥。2例在关胸后20min，3例在回重症监护病房后2－4h出现急性心肌缺血表现（明显心电图ST－T变化），伴室颤2例，5例血液动力学均不稳定，药物处理难以稳定血液动力学。全部患均立即送手术室（2例仍在手术室），急诊再次开胸。探查发现，2例患静脉桥（分别搭桥到回旋支第二钝缘支和右冠状动脉后降支）内急性血栓形成；另3例所有静脉桥良好，但左室前壁收缩运动明显减弱，结合心电图变化，诊断为左乳内动脉灌注不良。重新建立体外循环，清除桥内血栓重新搭桥2例（1例在非体外循环心脏跳动下进行）；另取一段静脉搭桥到左乳内动脉－左前降支吻合口远端的左前降支3例。结果：5例患顺利度过手术，均置入主动脉内球囊反搏，支持22－25h（平均42h）。手术后呼吸机支持4h－18d（平均7．3d）合并消化道出血4例，肾功能不全2例，肺部感染2例，切口感染1例。手术后住院时间12－35d，平均21d。全组均痊愈出院。结论：冠状动脉搭桥围术期急性心肌梗死应重在预防。如怀疑桥有问题，急诊再搭桥是良好选择，但手术后并发症发生率明显增加。     

One-year clinical outcomes after complete arterial coronary revascularization

BACKGROUND: Conventional coronary bypass surgery applies single internal mammary arteries and saphenous vein graft conduits for revascularization of occluded coronary arteries. While the use of saphenous vein grafts is limited by early graft occlusion, little data exist on clinical experiences with complete arterial revascularization. PATIENTS AND METHOD: From January 2003 to July 2004, 390 patients were transferred from Red Cross Hospital Cardiology Center to the Rotenburg Cardiovascular Center for coronary bypass operation. From these patients, 200 were selected for complete arterial revascularization. Mean age of the patients was 66.7+/- 8.0 years; 80.5% were male; 68.5% had triple-vessel disease, 31% had two-vessel disease, and 0.5% had single-vessel disease; 32% were diabetic; and 6.5% had a previous bypass operation. Left ventricular ejection fraction was >50% in 85.5% and 30-50% in 14.5%. Double internal mammary artery grafts were used in 98% and single internal mammary artery grafts in 2%. In 51%, the right internal mammary artery was connected with the left internal mammary artery as a T-graft and in 17%, it was used as a free aortocoronary graft. Radial artery grafts were used in 4%. The average number of anastomoses per patient was 3.4. RESULTS: During the primary in-hospital stay, 1.5% of the patients had to undergo reoperation, 3.5% had myocardial infarctions, 3.5% had wound healing complications, 1.0% experienced an ischemic stroke, and 1 patient died following an acute myocardial infarction. At 12 months, 1.0% underwent percutaneous reinterventions, 0.5% had to be reoperated, 0.5% had a myocardial infarction, and 1.0% died. The actuarial survival rate at 12 months was 99%. CONCLUSION: When both the internal mammary arteries are used as the preferred surgical strategy, complete arterial revascularization can be performed with excellent clinical results over 12 months.     

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)     

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.     

Multiple anastomosis with the internal mammary arteries

Between February 1984 and June 1985 90 consecutive patients underwent a surgical procedure of myocardial revascularization with multiple anastomoses, using one or both internal mammary arteries by single or sequential anastomoses. In 53 cases venous graft were also used. 86 cases had elective surgery and 4 had emergency surgery for unstable angina. Most of the patients had triple vessels disease; left main stenosis was present in 14. Left ventricular ejection fraction was less than 0.35 in 8 cases. A single internal mammary artery was used in 61 patients with sequential anastomoses; in 3 of these a triple sequential anastomoses was performed. In 29 patients both mammaries were used, 6 of these were anastomosed in double sequential way. Right mammary was always sewn on the marginal branch of the circumflex artery through the transverse sinus. The incidence of perioperative myocardial infarction was 2.2%. There was no hospital mortality. Reparative surgery to control immediate postoperative bleeding was required in 5 patients (5.5%). 5 cases presented a wound infection. 32 sequential anastomoses were restudied angiographically: 30 of these were patent and 2 malfunctioning. There were two late deaths: one 5 months postoperative, for gastric hemorrhage and the second one 6 months after surgery for inferior myocardial infarction. Mean follow-up of 10 months was complete in 88 surviving patients of whom 80 (91%) were asymptomatic, and 8 cases had residual angina: 5 only during exercise, 3 at rest. We conclude that the extended use of the internal mammary artery grafting, as single or sequential anastomoses, is technically feasible and provides adequate perfusion to the area of myocardium supplied by such grafts.     

Percutaneous transluminal angioplasty involving internal mammary artery grafts

With the increasing use of the internal mammary artery as the conduit of choice in coronary bypass surgery, it is anticipated that an expanding patient population will have stenosis, usually at the site of internal mammary-to-coronary artery anastomosis. In our series 31 patients underwent dilatation at either the site of anastomosis (24), the native coronary artery beyond the anastomosis (4), or both (3) with no mortality, myocardial infarction, or need for emergency coronary artery bypass surgery. Angiographic and clinical success was achieved in 28 patients (90%). There were two internal mammary artery dissections with both patients requiring elective coronary bypass surgery. Of the patients in whom dilatation was successful, 22 (79%) have been followed for longer than 6 months and 19 (86%) have had sustained functional improvement at a mean of 35 months after angioplasty. One patient is to undergo repeat coronary bypass surgery. No patient has had a myocardial infarction or died during follow-up. Although percutaneous transluminal coronary angioplasty of the internal mammary artery has inherent difficulties because of the anatomic characteristics of the vessel, it can be performed with a high degree of primary success and a low incidence of complications and can provide long-term clinical improvement.     

ST-Segment elevation acute myocardial infarction due to severe hypotension and proximal left subclavian artery stenosis in a prior coronary artery bypass graft patient

Proximal subclavian artery stenosis may result in cardiac ischemia in coronary artery bypass graft patients with internal mammary grafts. We report a case of acute anterior myocardial infarction in such a patient who developed severe systemic hypotension. Symptoms and electrocardiographic changes resolved after proximal left subclavian artery stenting. Subclavian angiography should be considered in all prior coronary artery bypass graft patients with internal mammary grafts undergoing coronary angiography.     

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)     

Plexus between internal mammary graft and pulmonary vasculature after minimally invasive coronary surgery

We report a complication associated with minimally invasive direct coronary artery bypass grafting surgery The patient suffered a nonfatal anterior myocardial infarction 1 day after he underwent minimally invasive bypass grafting using the internal mammary artery. Two months later, coronary arteriography revealed a fistulous connection between the left internal mammary graft and the left pulmonary vasculature. To our knowledge, this particular complication has not been reported following minimally invasive coronary surgery.     

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.     

Challenges associated with treatment of left internal mammary artery graft thrombosis

Acute occlusion of the left internal mammary artery (LIMA) graft late after coronary artery bypass grafting surgery is a rare and potentially life‐threatening complication. We describe a case of acute myocardial infarction 19 years after coronary artery bypass graft surgery due to acute occlusion of the distal anastomosis of a LIMA graft to the left anterior descending artery. Aspiration thrombectomy failed to remove the thrombus. Laser thrombectomy caused perforation. After drug‐eluting and covered stent implantation, antegrade TIMI 3 flow was restored with an uneventful postprocedural course.     

Myocardial revascularization using both internal mammary arteries. Clinical results and surgical strategy

To improve the benefits from coronary artery grafting with internal mammary artery (IMA) several technical manoeuvres and methods have been developed to increase the number of coronary arteries and their branches that can be bypassed with internal mammary arteries. Between November 1985 and December 1986, 50 patients underwent a surgical myocardial revascularization procedure using both internal mammary arteries by single or sequential anastomoses and supplemental saphenous vein graft. In 42% of these patients complete revascularization was achieved employing only internal mammary artery grafts. One hundred and twenty-six internal mammary artery grafts (77% of the total coronary bypass performed), were placed. One patient developed perioperative myocardial infarction. Reparative surgery to control immediate post-operative bleeding was required in two patients. Post-operative coronary angiography performed in 30 patients showed all patent internal mammary artery grafts but one. No late deaths occurred. Mean follow-up of 10 months was complete in 50 patients, of whom 94% are symptom free. We conclude that bilateral internal mammary artery grafting can be performed with low operative risk and can provide excellent long-term functional improvement and survival employing only high patency arterial conduit. Moreover, it doesn't significantly increase surgical morbidity.     

Internal mammary artery versus saphenous vein graft. Comparative performance in patients with combined revascularisation

Thirty three patients with coronary artery disease undergoing combined myocardial revascularisation with internal mammary artery and saphenous vein grafts underwent angiographic studies up to 10 years after operation. Each patient had one internal mammary artery graft and one or more saphenous vein grafts. Eleven symptom-free patients, studies one month to five years (mean 1.9 years) after operation, had intact internal mammary artery and saphenous vein grafts in a good state of preservation. Of the six patients developing symptoms within the first year after surgery, three had evidence of poor flow in the internal mammary artery graft because of large side branches and the other three had stenosis or occlusion of the saphenous vein grafts. Sixteen patients developed symptoms after several years free of symptoms and were studied three to 10 years (mean six years) after operation. Of the 23 saphenous vein grafts in this group, 17 (74%) were either occluded or severely stenosed and six (26%) were in good condition. One internal mammary artery graft was occluded and the remaining 15 were in good condition. Saphenous vein graft failure was the predominant cause of late development of symptoms in patients with combined revascularisation. Long term performance of the internal mammary artery grafts is far superior to the saphenous vein grafts.     

Internal mammary artery versus saphenous vein graft. Comparative performance in patients with combined revascularisation.

Thirty three patients with coronary artery disease undergoing combined myocardial revascularisation with internal mammary artery and saphenous vein grafts underwent angiographic studies up to 10 years after operation. Each patient had one internal mammary artery graft and one or more saphenous vein grafts. Eleven symptom-free patients, studies one month to five years (mean 1.9 years) after operation, had intact internal mammary artery and saphenous vein grafts in a good state of preservation. Of the six patients developing symptoms within the first year after surgery, three had evidence of poor flow in the internal mammary artery graft because of large side branches and the other three had stenosis or occlusion of the saphenous vein grafts. Sixteen patients developed symptoms after several years free of symptoms and were studied three to 10 years (mean six years) after operation. Of the 23 saphenous vein grafts in this group, 17 (74%) were either occluded or severely stenosed and six (26%) were in good condition. One internal mammary artery graft was occluded and the remaining 15 were in good condition. Saphenous vein graft failure was the predominant cause of late development of symptoms in patients with combined revascularisation. Long term performance of the internal mammary artery grafts is far superior to the saphenous vein grafts.     

Skeletonized bilateral internal mammary arteries for total arterial myocardial revascularization

BACKGROUND: Bilateral internal mammary artery (IMA) grafting is associated with an improved long-term survival, low rates of recurrence of angina and late myocardial infarction. However, because of the inadequate length of the conduit, use of bilateral internal thoracic artery grafting occasionally is not suitable for complete revascularization. To overcome this limitation, extra length can be obtained by skeletonization of both IMAs. We decided to prospectively assess the safety of this technique. METHODS: One hundred patients with a mean age of 52.5 +/- 13.1 years underwent complete revascularization with skeletonized bilateral internal mammary arteries on cardiopulmonary bypass (CPB). The right internal mammary artery (RIMA) was used as a free graft connected to the in situ left IMA (LIMA) in 88 patients. A free LIMA was attached to in situ RIMA in 12 patients. The average number of grafts was 3.2 per patient (range: 2-4 grafts per patient). Mean left ventricular ejection fraction was 60% (range: 25-80%). RESULTS: No patient required reexploration for bleeding, and no patient died within 30 days after operation. On the basis of electrocardiographic changes, three patients sustained a perioperative myocardial infarction. One patient had a sternal wound infection. Mean follow-up was 24 months (range: 6-36 months). The actuarial survival rate was 99 +/- 1% at 3 years. No myocardial infarctions were reported during the follow-up. Three patients had recurrent angina with conduit occlusion diagnosed on coronary angiography. CONCLUSION: Complete myocardial revascularization with skeletonized bilateral internal mammary arteries is a safe and reliable technique with excellent early and mid-term results.     

Unstable angina and evolving myocardial infarction following coronary bypass surgery: pathogenesis and treatment with interventional catheterization

Effective therapy for patients with unstable angina or evolving myocardial infarction following coronary bypass surgery requires accurate delineation of the pathoanatomy and prompt intervention. We therefore performed cardiac catheterization in 10 consecutive patients: four with acute myocardial infarction and six with refractory unstable angina (NYHA class IV). All patients with acute myocardial infarction were found to have completely thrombosed vein grafts supplying totally occluded native coronary arteries. In three patients with evolving myocardial infarction occurring within 4 weeks of coronary bypass surgery, graft thrombosis was caused by venous valves in two patients and a suboptimal anastomosis in a third. The fourth patient sustained a myocardial infarction 7 years after coronary bypass surgery with atherosclerotic plaque rupture causing vein graft thrombosis. Therapy with intragraft streptokinase resulted in complete clearing of thrombus, pain relief, and control of injury current in all four patients. Rest angina with concomitant ST and T wave changes occurred in six patients. In two patients symptoms occurred early (within 6 months), whereas angina developed 4 to 10 years after coronary bypass graft surgery in four patients. In the two patients with early recurrence of symptoms suboptimal anastomosis was found in one, while the other patient had a venous valve in the vein graft in conjunction with a stenosis in the native coronary artery. In three of four patients with late recurrence of angina, symptoms developed as a result of atherosclerotic stenosis in their vein grafts; in the fourth patient an occluded graft was found to supply a stenosed native coronary artery.(ABSTRACT TRUNCATED AT 250 WORDS)     

Midterm clinical results in myocardial revascularization using the radial artery

STUDY OBJECTIVES: The aim of this study was to evaluate the immediate and midterm results of coronary artery bypass grafting with the radial artery (RA) as a conduit. PATIENTS: Two hundred forty-one patients underwent myocardial revascularization using the RA. In 78.5% of patients, three coronary vessels were involved, and in 25% of patients, the left main coronary artery was involved. The mean (+/- SD) preoperative ejection fraction was 58 +/- 13%. INTERVENTIONS: The RA was implanted on branches of the circumflex artery in 81% of the cases, and the left internal mammary artery was implanted on the left anterior descending artery in 94% of patients. Total arterial myocardial revascularization was performed in 58% of patients. Measurements and results: The in-hospital mortality rate was 0.8%. Two patients had acute myocardial infarction, and three patients experienced a transient low-cardiac output syndrome. We reviewed the records of all 171 patients who had undergone at least 6 months of follow-up after surgery. The late mortality rate in this group was 0.6% (one patient died 2 months after surgery because of cardiocirculatory arrest due to untreatable ventricular fibrillation). At a mean follow-up time of 545 +/- 253 days, two patients showed class 3 residual angina according to the Canadian Cardiovascular Society (CCS) guidelines. One patient required another hospital admission 6 months after undergoing surgery for PTCA/stenting on a circumflex artery that had not previously undergone bypass. The second patient, 8 months after undergoing coronary artery bypass grafting, underwent angiography and stenting on a stenosed anastomosis of a posterolateral branch of the circumflex artery that previously had been bypassed with the right internal mammary artery. CONCLUSIONS: The routine use of the RA for coronary bypass grafting is a safe surgical technique, providing excellent clinical mid-term results in terms of cardiac event-free expectancy.     

Coronary revascularization surgery with arterial conduits. The technic, results and 4-year follow-up in 1023 consecutive patients

OBJECTIVE: The main objective of the present study was to analyze the in-hospital and mid term results obtained in 1,023 consecutive patients undergoing coronary artery bypass surgery (CABG) in whom a combination of arterial grafts was used: radial arteries (RA) and one or both internal mammary arteries (IMA). METHODS: From May 1995 to May 1998, 1,023 consecutive patients underwent CABG alone, using arterial conduits (AC) (one or two IMA and RA) for myocardial revascularization. The left internal mammary artery (LIMA) was employed as an "in situ" graft, and the right internal mammary artery (RIMA) as a free graft or "in situ" both in combination with the RA. The latter was connected to the LIMA through a T or Y anastomosis, or emerged directly from the ascending portion of the aorta. RESULTS: An average of 3.2 bypasses per patient were performed. The LIMA was used in 100% of the patients. The RIMA was used in 21.7% and the RA in 100% of the cases. Operative mortality was 2.5% (26 patients) and 32 (3.1%) suffered perioperative acute myocardial infarction. The first 62 patients were angiographically re-studied before discharge, and a 98.4% patency of the AC used was found. Mean follow up time was 25.0 +/- 9.6 months (range, 1 to 48 months). CONCLUSIONS: a) myocardial revascularization procedures using a combination of mammary and RA grafts are safe; b) in-hospital and mid term morbidity and mortality are not higher than those observed with saphenous vein grafts; c) it is possible to achieve complete myocardial revascularization with only AC, even in patients with impaired left ventricular function, and d) AC can be used in elderly patients.     

Ischemic myocardial injury during coronary artery surgery

ECG's and serum levels of SGOT, LDH, and CPK were examined during the postoperative period in 50 patients with angina pectoris who had myocardial revascularization procedures. ECG signs of acute myocardial infarction appeared in 34 per cent and changes compatible with acute ischemic injury were seen in 10 per cent. Elevation of SGOT exceeding 90 units occurred in 32 per cent of 50 patients, and LDH levels over 900 units occurred in 24 per cent. In patients with ECG evidence of post-operative infarction or ischemia, 50 per cent had abnormal SGOT levels and 55 per cent had abnormal LDH levels. In 16 patients with SGOT levels exceeding 90 units, 69 per cent had ECG evidence of acute infarction or ischemia. Two patients died following surgery and acute myocardial infarction was demonstrated in both at autopsy. Relief of angina occurred in one patient who developed a myocardial infarct following internal mammary implantation. A follow-up angiogram revealed no effective communication of the implant with myocardial vessels. Acute myocardial infarction is a frequent complication of coronary artery surgery as determined by serial ECG's. In this study, approximately 50 per cent of these patients had diagnostic elevations of SGOT or LDH.