Standard coronary artery bypass grafting and beating heart bypass. Indications and long-term results

Meta-analysis of randomized trials comparing off-pump with on-pump coronary artery bypass graft patency

BACKGROUND

Off-pump coronary artery bypass graft surgery (OPCAB) is increasingly becoming a widely used technique and challenges conventional on-pump coronary artery bypass grafting as the standard surgical therapy for coronary artery disease. Little information, however, is available concerning postoperative performance of bypass grafts done with this new technique. The aim of this study is to assess differences in graft patency between OPCAB and coronary artery bypass grafting by meta-analysis of data published in randomized trials.

METHODS

A literature search for the period beginning January 1990 until December 2004 supplemented with manual bibliographic review was performed for all peer-reviewed English-language publications. A systematic overview (meta-analysis) of randomized trials was conducted to assess differences between OPCAB and coronary artery bypass grafting in graft occlusion rates.

RESULTS

Literature search yielded five comparable randomized studies, for a total of 872 and 998 grafts performed during OPCAB and coronary artery bypass grafting procedures, respectively. Meta-analysis of these studies showed an increased risk of graft occlusion in the OPCAB group of patients, both when all the studies were analyzed together (odds ratio, 1.51; 95% confidence intervals, 1.15 to 1.99; p = 0.003), and when low-quality (odds ratio, 1.46; 95% confidence intervals, 1.05 to 2.03; p = 0.02) and high-quality (odds ratio, 1.65; 95% confidence intervals, 0.99 to 2.75; p = 0.05) studies were analyzed separately.

CONCLUSIONS

Cumulative analysis of the few prospective randomized studies currently available in the literature documents a reduction in postoperative patency of coronary artery bypass grafts performed during OPCAB procedures. The risk of reduced graft patency needs to be considered when choosing OPCAB as tailored strategy for selected patients.

Coronary artery bypass surgery by the transdiaphragmatic approach

BACKGROUND

The transdiaphragmatic approach is useful for reoperative coronary artery bypass grafting involving the right coronary artery because it does not require median sternotomy or cardiopulmonary bypass.

METHODS

Twenty-one patients underwent coronary artery bypass surgery by the transdiaphragmatic approach. The ratio of first operations to reoperations was 7:14. The cause of reoperation was occlusion of a saphenous vein graft in 4 patients, right gastroepiploic artery graft failure in 3 patients, and a new sclerotic lesion in the right coronary artery in 7 patients. When the radial artery or saphenous vein was used, grafting extended from the origin of the gastroduodenal artery to the right coronary artery.

RESULTS

None of the patients died during surgery. The sites of anastomoses were as follows: right coronary artery in 11 patients, right posterior descending artery in 9 patients, and the atrioventricular node artery in 1 patient. The following types of grafts were used: right gastroepiploic artery in 17 patients, saphenous vein in 2 patients, and radial artery in 2 patients.

CONCLUSIONS

When reoperative coronary surgery involving the right coronary artery is necessary, the transdiaphragmatic technique is effective because it does not damage patent grafts placed during the primary operation.