"H" graft from the right internal mammary artery to the left anterior descending coronary artery: an alternative strategy in reoperative grafting of the LAD territory.

Reoperative grafting of the left anterior descending (LAD) coronary artery or its diagonal branches can be accomplished through a left anterior small thoracotomy (LAST) on the beating heart using the left internal mammary artery (LIMA) as a conduit. Patients in whom the LIMA has been used previously, however, are generally excluded from this approach unless an alternative technique is utilized. We describe a new technique applicable to these patients that consists of grafting the LAD through a LAST approach and connecting the graft to the right internal mammary artery (RIMA).

Does avoidance of cardiopulmonary bypass decrease the incidence of stroke in diabetics undergoing coronary surgery?

BACKGROUND: The adverse effects of diabetes mellitus on the coronary circulation and the higher incidence of cardiovascular events in diabetic patients are well documented [Johnson 1982]. Improvements in myocardial protection, revascularization techniques, and anesthetic management have had favorable impacts on coronary artery bypass grafting (CABG) outcome in diabetic patients. Despite that, diabetic patients are significantly more likely to have a prior history of myocardial infarction, congestive heart failure, peripheral vascular disease, and hypertension, as well as having a significantly greater baseline serum creatinine. The aim of our study was to record, compare, and analyze the stroke rate among patients with a history of preoperative diabetes undergoing "off-pump" CABG (OPCAB) with conventional cardiopulmonary bypass (CPB) CABG to determine whether the stroke rate in this higher risk population could be decreased by off-pump techniques. METHODS: The records of 1,227 patients with a pre-operative history of diabetes undergoing conventional CABG (973 patients, 79.3%) using cardiopulmonary bypass and off-pump CABG 254 (20.7%) were analyzed from 1995 through 1999. There were no differences in age, sex, or elective/urgent status of patients. Preoperative risk factors (gender distribution, carotid disease, ejection fraction, CHF, hypertension, previous MI) were identical in both groups. The goal of the operations were complete revascularization, which was achieved via median sternotomy in both groups. RESULTS: Our reported series reveals a stroke rate of 3.6% in the CPB group and 1.2% in the off-pump group. This evidence alone was not statistically significant, but two other high-risk criteria for stroke, re-do CABG and calcified aortas, revealed that the off-pump series had a higher percentage of each (26.4% redos in off-pump vs. 8.7% CPB redos, p < 0.005; 7.1% calcified aorta cases in the off-pump group vs. 2.9% in the CPB group, p < 0.004). The threefold reduction in stroke may be clinically significant in light of the higher-risk profile of the off-pump group. The limitations of this study are that it was retrospective, there were a small number of events, and different surgeons were involved in the two different approaches to these patients. CONCLUSIONS: Improvements in myocardial protection, revascularization techniques, and anesthetic management have made significant, favorable impacts on CABG outcome in diabetic patients. New diagnostic and therapeutic strategies must be developed to lessen the medical and economic implications of stroke. A larger series or a more effective way of analyzing preoperative risk may well have shown a statistically significant difference in the stroke incidence given the differences in preoperative risk factors/stroke predictors. Until such advances occur, a threefold reduction of stroke incidence using OPCAB certainly makes this technique a favorable one for high-risk diabetics requiring coronary revascularization.

Stroke in octogenarians undergoing coronary artery surgery with and without cardiopulmonary bypass.

BACKGROUND: Myocardial revascularization in elderly patients is associated with a morbidity and a mortality substantially higher than those observed in younger patients. The aim of this study was to analyze the potential benefits of coronary artery bypass grafting without cardiopulmonary bypass (CPB) for octogenarians. METHODS: Of 269 octogenarians who underwent coronary artery bypass grafting at our institution between January 1995 and May 1999, 172 had the operation with CPB (CPB group) and 97, without CPB (off-pump group). Revascularization of the circumflex system or right coronary artery were not considered contraindications to off-pump grafting. Demographic data, preoperative risk factors, comorbid conditions, angiographic findings, postoperative complications, and outcomes were compared. RESULTS: The groups were comparable for age, sex, Canadian Cardiovascular Society class, operative priority (elective, urgent, or emergent), preoperative risk factors, and left ventricular ejection fraction. A significantly higher proportion of reoperations was observed in the off-pump cohort (16 of 97, 16.5%) compared with the CPB cohort (8 of 172, 4.7%) (p = 0.002). There was a trend toward a higher graft-patient ratio in the CPB group (3.3 versus 1.8; p = not significant). Freedom from postoperative complications was significantly higher in the off-pump group than in the CPB group (83 of 97, 85.6%, versus 129 of 172, 75%; p = 0.04). The incidence of stroke was 0% in the off-pump cohort compared with 9.3% (16 of 172) in the CPB cohort (p < 0.0005). Although there was a trend toward higher 30-day and risk-adjusted mortality rates in the off-pump group than in the CPB group (10.3% versus 5.2% and 2.8% versus 1.8%, respectively), the differences were not significant. The length of hospitalization was slightly lower in the off-pump group (9.1 versus 10.8 days; p = not significant). CONCLUSIONS: This investigation suggests that patients 80 years of age and older undergoing off-pump coronary artery bypass grafting can experience significantly lower rates of perioperative stroke and overall complications compared with those undergoing the same procedure with CPB, although a trend toward higher mortality rates was observed in the off-pump group.

Nerve expansion. The optimal answer for the short nerve gap. Behavioral analysis.

Treatment of the short nerve gap remains a challenge for the reconstructive surgeon, but it is a clinical problem that can be addressed by nerve expansion. In the present study, the effects of slow nerve expansion on the walking behavior of the rat were examined. When expansion was applied on a normal sciatic nerve or on a transected nerve at either the proximal or the distal segments, permanent 30% elongation could be achieved. The recovered function from the expanded nerve stumps was compared with such classical methods of nerve reconstruction as nerve graft, coaptation under moderate tension, and tensionless repair. The results compared favorably between the expanded groups and the time-honored methods of nerve repair. Analysis of the behavioral data indicated that any amount of expansion affected the functional capabilities of the involved nerve. However, expansion of a normal nerve and/or proximal segment of a transected nerve was better tolerated than distal segment expansion, which suggests that the presence of an axon may have a beneficial effect in minimizing the deforming mechanical insult. Slow nerve expansion appears to have a definite role in the microsurgical management of the short nerve gap.