Outcome analysis of coronary artery bypass grafting: minimally invasive versus standard techniques

Minimally invasive coronary artery bypass grafting (MIDCAB) procedures are purported to result in improvements in patient management over standard tec hniques. A comparative study was performed on risk-stratified patients trea ted with either technique. Following institutional review board approval. a retrospective random chart review was conducted on 27 MIDCAB and 37 standa rd coronary artery bypass grafting (CABG) patients who were operated on ove r a 12-month period at the University of Nebraska Medical Center. Risk stra tification was accomplished by dividing the two patient populations. MIDCAB and 'standard', into one of four subgroups based on a preoperative risk sc ore. Risk stratification was achieved by dividing the patient populations i nto one of four subgroups: good, fair poor and high risk. Both groups recei ved similar operations and surgical interventions, except for the inclusion of cardiopulmonary bypass (CPB). Approximately 200 parameters were collect ed and analyzed in the following categories: anthropometric, operative and postoperative outcomes. The MIDCAB group had a significantly lower number of vessels bypassed (2.0 +/- 0.7 vs 3.4 +/- 0.9. p < 0.0001). Total postoperative blood product tran sfusions trended higher in the standard group (6.1 +/- 12.6 U) when compare d to the MIDCAB patients (2.3 +/- 5.5 U, p +/- 0.15). although not statisti cally significant. Postoperative inotrope use was significantly less in the MIDCAB group (19% vs 59%, p < 0.002). Ventilator time in the MIDCAB group was 10.5 +/- 5.4 h vs 15.0 +/- 12.3 h in the standard group (p < 0.07). The MIDCAB group had an overall greater length of stay, but was only statistic ally different within the poor-risk subgroup (12.2 +/- 10.7 vs 7.5 +/- 3.9. p < 0.04). The results of this study show that when CPB is not utilized in treating pa tients undergoing CABG procedures, the benefits in regards to patient outco mes are unclear. This necessitates the need for further work when comparing outcomes for risk-stratified patients.