Long-Term Outcomes of the Symmetry Vein Graft Anastomosis Device

Abstract

The Symmetry Bypass Connector (St. Jude Medical) was developed to rapidly anastomose saphenous vein grafts to the aorta during coronary bypass surgery (CABG) without cross-clamping. Previous uncontrolled studies of this device observed vein graft closures at six months, possibly attributable to neointimal hyperplasia. To assess the long-term clinical outcomes of the Symmetry device, we performed a retrospective matched case-control analysis of patients who underwent CABG at Duke Medical Center between January 1, 2002 and December 31, 2003. In 121 patients, at least one proximal anastomosis used a Symmetry device. Traditional suture methods were used in 178 control patients, matched by age group, gender, use of cardiopulmonary bypass, and Hannan perioperative risk score. One-year outcomes were compared using the log-rank test and Cox proportional hazards regression models. Major adverse events were more frequent among cases compared with controls. By unadjusted Kaplan-Meier analysis for the composite end point of death, nonfatal myocardial infarction, repeat cardiac catheterization, or repeat CABG, there was a trend towards increased events in the Symmetry device group (P=0.053). No significant differences were detected for stroke, all cause mortality, or the combined end point of death or nonfatal myocardial infarction. Use of the Symmetry Bypass Connector was associated with increased risk for major adverse events at 1 year, suggestive of early graft closure. The potential reductions in operative stroke risk (from the elimination of aortic cross-clamping) must be weighed against the potential risk for later adverse events. These findings encourage close follow-up of patients who received this device.