Background: 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.
Methods and results: 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.
Conclusions: 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.