Yosef Paz

Bilateral internal thoracic artery grafting : midterm results of composite versus in situ crossover graft

BACKGROUNDnTwo common techniques of bilateral internal thoracic artery grafting are the composite T graft and in situ crossover graft. The superiority of one method over the other has not yet been established.nnnMETHODSnFrom April 1996 to July 1999, bilateral skeletonized internal thoracic arteries were used as T grafts (composite group, n = 649) and in situ grafts (cross group, n = 351) in 1,000 consecutive patients. In the cross group, in situ right internal thoracic artery was routed anterior to the aorta across the midline for grafting to the left anterior descending artery, and the left internal thoracic artery was used for the circumflex branches.nnnRESULTSnThe two groups had comparable preoperative risk profiles. Bypass time and aortic cross-clamping time were longer in the composite group (80 +/- 38 and 67 +/- 29 minutes versus 66 +/- 43 and 55 +/- 34 minutes, respectively). Number of anastomoses per patient was similar (3.1 versus 3.2). However, more sequential anastomoses were performed in the composite group (62% versus 53%), and the gastroepiploic artery was used more often in the cross group (30% versus 19%). Thirty-day mortality was 3.9% in the composite and 2.3% in the cross group (not significant). Occurrence of postoperative complications (sternal infection, myocardial infarction, cerebrovascular accident, and bleeding) was similar. Late follow-up (2 to 56 months) showed increased return of angina (6% versus 3.1%; p = 0.046) and decreased 4-year survival (Kaplan-Meier; 86% +/- 2.7% versus 92.4% +/- 1.5%; p = 0.07) in composite patients.nnnCONCLUSIONSnEarly results of bilateral internal thoracic artery grafting with composite T graft are comparable with those of in situ grafts. However, increased angina return and decreased midterm survival led us to recommend in situ grafting whenever technically possible.

Technical aspects of double-skeletonized internal mammary artery grafting

BACKGROUNDnBilateral internal mammary artery (IMA) grafting is performed to provide complete arterial myocardial revascularization with the intention of decreasing postoperative return of angina and the need for reoperation. We present here technical views of double-skeletonized IMA grafting, and evaluate its clinical outcome.nnnMETHODSnSkeletonized IMA is harvested gently with scissors and silver clips, without use of cauterization, and embedded in a small syringe filled with papaverine. Three strategies for arterial revascularization were employed in 762 consecutive patients: (1) the cross arrangement (242 patients, 32%), where the in situ right internal mammary artery (RIMA) is used for the left anterior descending artery (LAD), in situ left internal mammary artery (LIMA) to circumflex marginal branches and the gastroepiploic artery for the right coronary artery (RCA); (2) the composite arrangement (476 patients, 62%), where free IMA is attached end-to-side to the other in situ IMA; and (3) the natural arrangement (44 patients, 6%), where the in situ RIMA is connected to the RCA and in situ LIMA to LAD. Mean age was 66 years (range 30 to 92). Two hundred ninety-two patients (38%) were older than 70, and 229 (30%) were diabetic.nnnRESULTSnOperative mortality was 2.5% (n = 19). The mortality of urgent and elective cases was 1.2% (8 of 663), and that of emergency operation was 11% (11 of 99). There were 9 (1.2%) perioperative myocardial infarctions, and 10 patients (1.3%) sustained strokes. Sternal wound infection occurred in 14 (1.8%).nnnCONCLUSIONSnThe three strategies described here provide the surgeon with the versatility required for arterial revascularization with bilateral IMAs in most patients referred for coronary artery bypass grafting.

Emergency myocardial revascularization for acute myocardial infarction: survival benefits of avoiding cardiopulmonary bypass

OBJECTIVEnEmergency coronary artery bypass grafting (CABG) for acute myocardial infarction (AMI) is associated with increased operative mortality. It has been suggested that this mortality might be reduced by performing the operation without cardiopulmonary bypass (CPB).nnnMETHODSnBetween January 1992 and April 1998, 77 patients underwent emergency CABG within 48 h of AMI. Thirty seven were operated on with CPB, and 40 without CPB. The two groups were similar regarding age, gender, left-ventricular ejection fraction (EF) and preoperative use of intra-aortic balloon pump (IABP; 50%). The mean number of grafts/patient was 3 in the CPB group, and 1.9 in the No-CPB group (P<0.0001).nnnRESULTSnOperative mortality in the CPB group was 24% (nine of 37) compared to 5% (two of 40) without CPB (P=0.015). Follow-up ranged between 6 and 66 months. There were no late deaths in the CPB group compared to nine (22%) in the No-CPB group (P<0.0066). Patients operated on with CPB had lower rates of recurrent angina (0 versus 15%; P=0.04) and re-interventions (0 versus 15%; P=0.04).nnnCONCLUSIONSnOur experience suggests that CABG without CPB is the preferred method of myocardial revascularization, due to the fact that it carries lower mortality than CABG with CPB. The trade-off includes increased rates of recurrent angina, re-interventions and late mortality.

Routine Use of Bilateral Skeletonized Internal Thoracic Artery Grafting Long-Term Results

Background— Skeletonized harvesting of the internal thoracic artery (ITA) decreases the severity of sternal devascularization, thus reducing the risk of postoperative sternal complications in patients undergoing bilateral ITA grafting. Methods and Results— Between 1996 and 2001, 1515 consecutive patients underwent skeletonized bilateral ITA grafting. Of the 1179 male and 336 female patients, 641 (42.3%) were >70 years of age, and 519 (34.2%) had diabetes mellitus. Operative mortality was 2.8%. Early postoperative morbidity included sternal infection (1.6%), cerebrovascular accident (3%), and perioperative myocardial infarction (1%). Multiple regression analysis showed chronic obstructive pulmonary disease (odds ratio, 11.3; 95% confidence interval [CI], 4.45 to 28.55), repeat operation (odds ratio, 12.7; 95% CI, 3.25 to 49.56), and diabetes mellitus (non–insulin dependent: odds ratio, 4.64; 95% CI, 1.85 to 11.59; insulin dependent: odds ratio, 6.9; 95% CI, 1.35 to 35.27) to be associated with increased risk of sternal infection. Follow-up (between 5 and 12 years) revealed 305 late deaths. Kaplan-Meier 10-year survival rates for patients <65, 65 to 74, and >75 years of age were 87%, 75%, and 52%, respectively. Cox regression analysis revealed increased overall mortality (early and late) in patients with peripheral vascular disease (hazard ratio [HR], 1.8; 95% CI, 1.39 to 2.33), patients >75 years of age (HR, 7.23; 95% CI, 4.16 to 12.55), those undergoing repeat operations (HR, 2.22; 95% CI, 1.27 to 3.89), patients with preoperative congestive heart failure (HR, 1.64; 95% CI, 1.29 to 3.75), and those with chronic renal failure (HR, 1.52; 95% CI, 1.11 to 2.01). Operations performed without cardiopulmonary bypass were associated with better postoperative survival (HR, 0.66; 95% CI, 0.49 to 0.87). Conclusions— Bilateral ITA grafting is associated with low morbidity and good long-term results. Use of skeletonized bilateral ITA is appropriate for the elderly and most patients with diabetes; however, it is not recommended for repeat operations or for patients with chronic obstructive pulmonary disease.

Arterial myocardial revascularization with in situ crossover right internal thoracic artery to left anterior descending artery.

BACKGROUNDnThe extra length obtained by skeletonizing the internal thoracic arteries (ITAs) enables versatile use of in situ bilateral ITAs for coronary artery bypass grafting, as the longer skeletonized right ITA more easily reaches the anastomotic site on the left anterior descending coronary artery.nnnMETHODSnBetween April 1996 and November 1999, 365 consecutive patients underwent revascularization with bilateral in situ ITAs (29% of 1,250 grafting procedures performed with both ITAs in our department during this period). The right ITA was routed anterior to the aorta to graft the left anterior descending coronary artery, and the in situ left ITA was used to graft circumflex branches. Right coronary artery branches were grafted with right gastroepiploic artery or saphenous vein graft. The right ITA crossed the midline above the aorta at the most cranial point to avoid damage in case of a repeat sternotomy in the future.nnnRESULTSnThe operative mortality rate was 2.2% (8 patients). Postoperative morbidity included seven strokes (1.9%), eight sternal wound infections (2.2%), and four perioperative myocardial infarctions (1.1%). Follow-up (6 to 49 months) of 97% of hospital survivors showed a return of angina in 3%. Postoperative coronary angiography (22 patients) revealed a 95% patency rate of both ITAs. One-year and 4-year survival rates (Kaplan-Meier) were 95% and 92.4%, respectively. Important predictors of an early unfavorable event were chronic obstructive pulmonary disease, old age (> or = 70 years), emergency operation, and diabetes. Chronic obstructive pulmonary disease was the only independent predictor of sternal wound infection (odds ratio, 15; 95% confidence interval, 2.8 to 80). It also predicted decreased late survival (hazard ratio, 8.3; 95% confidence interval, 3 to 21.5).nnnCONCLUSIONSnWith skeletonized dissection of ITAs, the right ITA easily reaches the left anterior descending coronary artery for left-sided arterial revascularization with in situ bilateral ITAs. This procedure is safe, but we recommend avoiding its use in patients with chronic obstructive pulmonary disease.

Routine use of bilateral skeletonized internal mammary arteries for myocardial revascularization

BACKGROUNDnComplete arterial myocardial revascularization without the use of saphenous veins grafts was primarily performed on selected patient populations such as the young and nondiabetic. In a recently developed surgical technique, the internal mammary artery is dissected gently as a longer skeletonized artery, providing greater versatility for complete arterial revascularization, without saphenous veins grafts.nnnMETHODSnWe prospectively evaluated the impact of the routine use of double skeletonized internal mammary artery in 472 patients who underwent coronary artery bypass grafting between April 1996 and June 1997. Their average age was 65 years (30 to 87 years), 383 (83%) were men, and 89 (17%) women. One hundred sixty-nine (36%) of the patients were older than 70 years, and 145 (31%) were diabetic. The average number of grafts was 3.2 per patient (two to six grafts).nnnRESULTSnOperative mortality was 1.7% (n = 8). The mortality of urgent and elective patients was 0.7% (3 of 410 patients), and that of emergency operations was 8.1% (5 of 62 patients; p < 0.01). There were three (0.6%) perioperative infarcts, and 6 patients (1.3%) sustained strokes. Sternal wound infection occurred in 8 patients (1.7%). Postoperative follow-up (1 to 25 months) was available in 462 patients (99%). Two-year actuarial survival was 96.8%, and 92% of the surviving patients are well and free of angina. Neither diabetes mellitus nor old age (>70 years) were significant independent predictors of any early or late untoward events. None of the 70 diabetic patients more than 65 years of age developed sternal wound infection. Chronic lung disease was found to be the only independent predictor for sternal infections.nnnCONCLUSIONSnRoutine use of bilateral skeletonized internal mammary artery is a safe replacement for the current myocardial revascularization technique even in the old and diabetic patients.

Myocardial revascularization for acute myocardial infarction: benefits and drawbacks of avoiding cardiopulmonary bypass

BACKGROUNDnCoronary artery bypass grafting (CABG) for acute myocardial infarction (AMI) is associated with increased mortality compared with CABG in non-AMI patients. Operating without cardiopulmonary bypass (CPB) might reduce this mortality.nnnMETHODSnBetween January 1992 and December 1998, 225 patients underwent CABG within 7 days of AMI, 119 with CPB and 106 without. The two groups were similar regarding age, gender, left ventricular dysfunction, and incidence of cardiogenic shock. Mean number of grafts per patient was 3.1 in the CPB group, and 1.7 in the no-CPB group (p < 0.0001).nnnRESULTSnOperative mortality in the CPB group was 12% compared with 3.8% without CPB (p = 0.027). Independent predictors of operative mortality were preoperative use of intraaortic balloon counterpulsation (IABP), nonuse of internal thoracic artery (ITA) to the left anerior descending artery, and the use of less than three grafts. Mortality of patients operated on with CPB within 48 hours of AMI was significantly higher (16.5% vs 4.3%, respectively; p = 0.044). However, patients operated on after 48 hours had similar mortality (5.8% vs 3.4%, respectively). Follow-up ranged from 6 to 84 months. Five-year survival (Kaplan-Meier) of both groups was similar (81%). Patients operated on with CPB had similar rates of recurrent angina; however, they had lower prevalence of reinterventions (0.8% vs 6.3%; p = 0.03).nnnCONCLUSIONSnOur study suggests that CPB can be used safely for most patients referred for CABG within the first week of AMI. However, for emergency patients operated on within the first 48 hours of symptom onset, we advocate avoiding CPB because it is associated with lower operative mortality.

Graft of choice to right coronary system in left-sided bilateral internal thoracic artery grafting

BACKGROUNDnThe complementary graft of choice to the right coronary artery system in patients undergoing left-sided bilateral internal thoracic artery grafting has yet to be determined. Saphenous vein graft (SVG) was compared with right gastroepiploic artery (RGEA) as the supplemental conduit to the right coronary artery when left-sided bilateral internal thoracic artery grafting is implemented.nnnMETHODSnFrom April 1996 to July 1999, 234 patients underwent bilateral internal thoracic artery grafting to the left coronary system with RGEA grafted to the posterior descending artery (RGEA group). They were compared with 127 patients with left-sided bilateral internal thoracic artery in whom SVG was used for grafting the right coronary system (SVG group).nnnRESULTSnFemale sex (27% versus 14.5%), diabetic patients (40% versus 27%), emergency cases (21% versus 7.3%), and left main coronary artery disease (34% versus 23%) were more prevalent in the SVG group. Number of grafts per patient was higher in the SVG group (3.8 versus 3.5, p = 0.04). Thirty-day mortality was 3.9% in the SVG and 2.6% in the RGEA group (not significant). Occurrence of postoperative complications (myocardial infarctions, strokes, bleeding, and sternal infections) was similar. Return of angina was similar (1.6% versus 3.8% in the SVG and RGEA groups, respectively). Midterm follow-up (4 to 56 months) showed comparable 1-year and 4-year survival (Kaplan-Meier) for both groups (92.8% and 91.7% in the SVG group, and 94.7% and 88% in the RGEA group, respectively).nnnCONCLUSIONSnIn patients undergoing left-sided bilateral internal thoracic artery grafting, the use of RGEA for revascularization of the right coronary system does not confer clinical benefits over SVG after midterm follow-up.

Should Bilateral Internal Thoracic Artery Grafting Be Used in Elderly Patients Undergoing Coronary Artery Bypass Grafting

Background— Although bilateral internal thoracic artery grafting is associated with improved survival, the use of this technique in the elderly is controversial because of their increased surgical risk and shorter life expectancy. The purpose of this study was to evaluate the effect of age on outcome of patients undergoing bilateral internal thoracic artery grafting. Methods and Results— Between 1996 and 2001, 1714 consecutive patients underwent skeletonized bilateral internal thoracic artery grafting, of whom 748 were ⩽65 years of age, 688 were between 65 and 75 years of age, and 278 were ≥75 years of age. Operative mortality of the 3 age groups (1.2%, 4.1%, and 5.8%, respectively) was lower than the logistic EuroSCORE predicted mortality (3.9%, 6.5%, and 9.3%, respectively; P<0.001). There were no significant differences among the groups in occurrence of sternal infection (1.3%, 2.6%, and 1.4%, respectively; P=0.171). Mean follow-up was 11.5 years. Kaplan–Meier 10-year survival for patients ⩽65, 65 to 75, and >75 years of age was 85%, 65%, and 40%, respectively (P<0.001). These rates were better than the corresponding predicted Charlson Comorbidity Index survival rates (68%, 37%, and 20%, respectively; P<0.001 for all age groups), approaching survival of the sex- and age-matched general population (90%, 70%, and 41%, respectively). Age ⩽65 years (hazard ratio, 0.232; 95% confidence interval, 0.188–0.288) and age 65 to 75 years (hazard ratio, 0.499; 95% confidence interval, 0.414–0.602) were independent predictors of improved survival (Cox model). Conclusions— Bilateral internal thoracic artery grafting should be considered in patients >65 years of age because of the significant survival benefit obtained with this surgical technique with no additional risk of sternal wound infection related to age.

Composite arterial grafting with double skeletonized internal thoracic arteries

OBJECTIVESnComposite arterial grafting is a surgical technique for arterial myocardial revascularization, in which free arterial conduits are proximally anastomosed end-to-side to an intact internal thoracic artery (ITA). This report describes technical aspects and results of composite grafting using bilateral skeletonized ITAs.nnnMETHODSnFrom April 1996 to February 1999, 1057 patients underwent coronary artery bypass grafting (CABG) using bilateral skeletonized internal thoracic arteries. In 600 of them (57%), composite arterial grafting was performed. There were 452 men and 148 women. The mean age was 69 +/- 7 years. Two-hundred and six patients (34%) were diabetics, 84 (14%) had severe left ventricular dysfunction (ejection fraction of < 35%), and 26 (4.3%) underwent emergency operations. In 574 patients, the right ITA was used as a free graft connected to the in-situ left ITA. In 26, the free left ITA was attached to the in-situ right ITA, and in 38, mini-composite grafts (free distal left ITA on the left ITA, or free distal right ITA on the right ITA) were constructed. The average number of grafts was 3.0/patient (range, 2--6).nnnRESULTSnThe operative mortality was 2.8% (n = 17), and there were ten (1.7%), deep sternal wound infections. The mean follow-up was 25 months (range, 14--36 months). The 3-year survival was 92.5%. Ninety-seven percent of the surviving patients were angina-free.nnnCONCLUSIONSnWe currently perform this surgery routinely in most patients referred for CABG, and regard bilateral skeletonized internal thoracic arteries as the most appropriate arterial conduits for the composite technique.