Atushi Amano

Coronary artery bypass grafting using the gastroepiploic artery in 1,000 patients

BACKGROUND The gastroepiploic artery (GEA) has been used as a graft in 1,000 patients in our institution, and the clinical outcome and the angiographic long-term results were reviewed. METHODS Between June 1, 1991, and June 30, 2001, 1,000 consecutive isolated coronary artery bypass grafting procedures using the GEA were performed in the Shin-Tokyo Hospital Group. The perioperative data were retrospectively analyzed, and the late angiographic results, cardiac related events, and survival were examined. The end points of the follow-up study were death or the occurrence of a cardiac-related event. RESULTS The GEA was used in 767 men and 233 women (mean age, 63.8 +/- 9.4 years). The GEA was used as an in situ graft in 99.6% of patients and was anastomosed to the right coronary artery in 87.8% and the circumflex artery in 10.0%. In addition, the left internal mammary artery was used in 96.9% of patients, the right internal mammary artery in 28.5%, the radial artery in 41.7%, the inferior epigastric artery in 1.4%, and the saphenous vein in 40.1%. The hospital morbidity and mortality rates were 10.8% and 0.8%, respectively. No abdominal complications were observed. Postoperative myocardial infarction associated with GEA graft failure occurred in 2 patients. During the late follow-up of 4.0 +/- 2.3 years, cardiac-related events were observed in 155 patients. The actuarial 3- and 5-year event-free rates were 91.2% and 84.2%, respectively. There were 86 late deaths, 36 of which were cardiac related deaths. The actuarial 3- and 5-year survival rates were 96.6% and 92.6%, respectively. Angiography was performed on 437 patients within 1 year after operation and in 221 patients more than 1 year postoperatively (mean interval, 3.1 +/- 1.8 years). The actuarial 1-, 3-, and 5-year GEA graft patency rates were 98.7%, 91.1%, and 84.4%, respectively, and the actuarial 1-, 3-, and 5-year LIMA graft patency rates were 99.6%, 98.8%, and 97.0%, respectively (p < 0.0005). CONCLUSIONS The GEA was used for coronary artery bypass grafting with good perioperative results. However, the angiographic patency rate of the GEA was inferior to that of the internal mammary arteries. The late occurrence of angina attributed to GEA graft failure should be carefully monitored.

Coronary artery bypass grafting for patients with non-dialysis-dependent renal dysfunction (serum creatinine ≧2.0 mg/dl)

INTRODUCTION Patients with renal dysfunction carry a risk of coronary atherosclerosis. The purpose of this study was to evaluate the outcome after coronary artery bypass grafting (CABG) in patients with decreased renal function (serum creatinine > or =2.0 mg/dl). METHODS We retrospectively analyzed consecutive patients who had undergone isolated CABG at Shin-Tokyo Hospital between May 1, 1991 and April 31, 2000. Preoperative, perioperative, and follow-up data of the non-dialysis-dependent patients with preoperative serum creatinine equal to or more than 2.0mg/dl (group R, n=59) were collected, and compared with those of the control patients (serum creatinine < 2.0, group C, n=1666). Group R was further divided into the off-pump and on-pump CABG group and their perioperative results were compared. RESULTS Group R included 51 males and eight females with a mean age of 66.4. The mean number of anastomoses was not significantly different between groups; however, clump time and pump time were longer in group R. Postoperative recovery was longer in group R than in group C, which is associated with a more frequent occurrence of major complications (28.8% in group R and 10.7% in group C, P<0.0001) and mortalities (6.8% in group R and 0.5% in group C, P<0.0005). The patients who underwent off-pump CABG experienced relatively faster recovery than those who underwent on-pump CABG, despite decreased renal function. At the mean follow-up of 2.4 years, the actuarial 3-year survival rate of groups R and C were 75.3 and 96.9%, respectively (P<0.0001), excluding hospital mortality. The actuarial 3-year cardiac event-free rate was 76.7% in group R and 87.3% in group C (P<0.05). CONCLUSIONS Patients with decreased renal function carry significant operative risks and require prolonged hospital care. Even after adequate surgical revascularization was completed, the long-term cardiac event-free and survival rates in the patients with renal dysfunction were inferior to the patients with normal renal function.

Surgical management of unstable patients in the evolving phase of acute myocardial infarction

BACKGROUND Acute myocardial infarction (AMI) can be treated with thrombolysis or coronary catheter intervention; surgical treatment--coronary artery bypass grafting (CABG)--is reserved for the patients in whom other procedures have failed. We performed CABG in 47 patients during the evolving phase of AMI, and analyzed their short-term and long-term results. METHODS Preoperative, intraoperative, and postoperative data were analyzed in patients who underwent emergency CABGs for AMI between January 1, 1992, and July 31, 1998. CABGs performed more than 7 days after AMI were excluded from this study. RESULTS The subjects were 47 patients (33 males and 14 females) with AMI who were treated by emergency CABG. Intraaortic balloon pumping was used in 44 cases and percutaneous circulatory pulmonary support was used in 3 cases. The mean interval between the onset of AMI and surgery was 27.4 +/- 27.9 hours. The mean number of bypass grafts was 3.0 +/- 1.1, and at least 1 arterial conduit was used in 45 cases (95.7%). Aortic clamp time, pump time, and operative time were 64.7 +/- 31.7, 117.3 +/- 55.2, and 313.2 +/- 84.8 minutes, respectively. IABP or percutaneous cardiopulmonary support were removed in the intensive care unit (ICU) 30.0 +/- 28.9 hours after CABG. The patients were extubated 41.4 +/- 40.5 hours after surgery, remained in ICU for 4.7 +/- 2.7 days, and were discharged from the hospital after 27.0 +/- 22.5 days. Three patients died from multiorgan failure related to postoperative sepsis, and 8 cases of major complications were observed. The actuarial 5-year survival rate of the patients treated with CABG was 83.0%. CONCLUSIONS Surgical treatment in the unstable patients after AMI can be performed with acceptable risk. Arterial revascularization may contribute to improvement in long-term results.

Coronary artery bypass graft after esophagogastrectomy

A 71-year-old male with a history of retrosternal gastric bypass, after a resected esophageal carcinoma, developed angina pectoris due to stenosis of the left main trunk and the left anterior descending artery. The patient was treated with off-pump beating-heart coronary artery bypass approached via left thoracotomy. Two free conduits arising from the left internal mammary artery were utilized for this particular case, since the aortocoronary bypass was impossible due to the severely calcified aorta. Postoperative angiography confirmed good coronary flow and the patient has been symptom free for 6 months.

Stroke rate of off-pump coronary artery bypass; aortocoronary bypass versus in-situ bypass.

Off-pump coronary artery bypass (OPCAB) using in-situ grafts does not require aortic manip ulation, and it is theoretically free from the risk of stroke. Because of the limited availability of in-situ grafts, aortocoronary bypass has been conducted in addition to in-situ grafting. In this paper, the authors prospectively investigated whether or not on aortocoronary bypass increases the incidence of stroke after off-pump bypass. Perioperative data were collected prospectively from patients who underwent isolated off-pump bypass at their hospital group between March 1997 and February 2002. The patients were divided into 2 groups; group AC (patients with at least 1 aortocoronary bypass, n = 280) and group IS (patients with all in-situ grafts, n = 234). Patients with 3-vessel disease more frequently underwent aortocoronary bypass and patients with a history of stroke, calcified ascending aorta, or renal failure more often underwent in-situ graft. The number of distal anastomoses was greater in group AC (3.5 ± 1.0) than in group IS (2.7 ± 1.1), p < 0.0001. Patient recovery and complication rates were similar, including the occurrence of postoperative stroke: 3.0% (7/234) in group IS vs 0.7% (2/280) in group AC, p=0.051, NS. The graft patency and remote results were not significantly different between the 2 groups. Side clamping of the aorta used in off-pump aortocoronary bypass does not increase the risk of postoperative strokes compared to in-situ bypass. Postoperative stroke after OPCAB may depend on the patients preoperative comorbidities.

Risk analysis of urgent coronary artery bypass grafting

We analyzed the risk factors of morbidity and mortality associated with urgent coronary artery bypass grafting (CABG) for impending myocardial infarcton. Among 1,428 consecutive patients who underwent isolated on-pump CABG between 1992 and 1998, a total of 126 were urgent cases. Their inhospital and long-term data were analyzed by the Kaplan-Meier method or logistic model. The mean number of grafts performed during urgent CABG was 3.2, and arterial reconstruction was performed in 117 (93.9%) cases. Major postoperative complicatons occurred in 64 cases (50.8%), and there were 9 inhospital deaths (7.1%). Significant predictor of inhospital death, identified by multivariate analysis, was a history of cerebral vascular accident. During a mean follow-up period of 3.1 years, there was a total of 7 remote deaths giving an actuarial 5-year survival rate of 93.5% (excluding inhospital deaths). Remote cardiac events occurred in 23 patients, giving an actuarial 5-year event-free rate of 74.8%. Multivariate logistic regression analysis found that risk factors influencing cardiac events were poor left ventricular function, preoperative renal dysfunction, postoperative use of intra-aortic balloon pumping, and postoperative induction of dialysis, while those influencing survival were previous myocardial infarction. Comparing elective CABG performed in the same period, the inhospital mortality of urgent cases was 33.8 times higher. Among hospital-survivors, patients after urgent CABG demonstrated fair long-term survival and future development of cardiac events. All efforts to achieve complete revascularization and frequent use of the internal mammary artery may contribute to improving the long-term results; however, careful management is necessary for patients with poor cardiac function.

A Previous Mastectomy Does Not Increase Sternal Complications After Coronary Artery Bypass Grafting Regardless of Whether an Internal Mammary Artery is Used

A mastectomy for breast cancer may alter the selection of grafts or the postoperative outcomes after coronary artery bypass grafting (CABG). To clarify these points, a retrospective analysis of patients who underwent CABG after a mastectomy was undertaken. A total of 19 mastectomy patients (13 left, 6 right, and 1 bilateral mastectomy) were identified prior to CABG, and their perioperative data as well as late outcomes were examined. The studied group consisted of all females with a mean age of 68.8 +/- 6.2 years. The internal mammary artery (IMA) was used in 14 (73.7%) patients; however, there were no patients in whom bilateral IMAs were harvested. Among these 14 patients, an ipsilateral IMA was harvested in 6 and a contralateral IMA in 8. Alternative grafts were selected in 6 patients. A contralateral IMA or other graft conduits were utilized instead of an ipsilateral IMA. There were no in-hospital deaths or sternal wound complications. With a mean follow-up of 2.6 years, 3 patients died (1 cardiac death and 2 noncardiac deaths) and 1 patient developed angina due to de-novo coronary artery stenosis. In patients who have undergone a previous mastectomy, CABG using a single IMA is considered to be safe. If the IMA has good pulsation and if IMA harvesting is not difficult, even after a mastectomy, it can be used as a graft conduit without increasing the risk of sternal wound complications.