Comparison of the Neurologic Outcome according to the Method of Proximal Graft Anastomosis at the Aortic Side during Off-pump Coronary Artery Bypass Grafting: The Heartstring Sealing System versus Conventional Manual Anastomosis

Cho, Won Chul; Kim, Joon Bum; Kim, Hee Jung; Kim, Hwan Wook; Kim, Yun Seok; Jung, Jae Seung; Choo, Suk Jung

Abstract

BACKGROUND: Side clamping of ascending aorta during proximal graft anastomosis in coronary bypassing surgery increases the risk of direct aortic injury as well as embolization of intimal atheroma. Heartstring proximal sealing system (Guidant Corporation, Santa Clara, Calif), developed to avoid aortic side clamping, may minimize risks of such complications. The aim of the current study is to compare the surgical outcomes of the two proximal anastomosis techniques i.e., Heartstring system versus aortic side clamping in off pump coronary bypassing surgery (OPCAB). MATERIAL AND METHOD: From January 2003 to August 2008, 499 patients underwent OPCAB. Of them, proximal graft anastomosis was performed using Heartstring system in 182 patients (Group I) and conventional manual anastomosis in 317 patients (Group II). The two groups were compared for postoperative major complications and mortality. RESULT: Two groups showed similar characteristics in terms of preoperative demographic data, left ventricular ejection fraction, renal function and history of diabetes, hypertension and smoking. Although there was no inter-group difference in the history of cerebral ischemia (p=0.48), preoperative brain magnetic resonance angiography revealed greater incidence of severe carotid artery stenosis (>75% of lumen) in the Group I than in the Group II (44.5% in the Group I and 30.0% in the Group II, p=0.003). There were no inter-group differences in postoperative mortality (p=0.40) and complications (p=0.47) including neurologic events (3 in the Group I and 2 in the Group II, p=0.258). Whereas neurologic events all comprised transient ischemic attacks in the Group I, they comprised multiple embolic strokes in the Group II. One patient in the Group II experienced aortic dissection during proximal anastomosis which resulted in ascending aortic replacement.
CONCLUSION
Although proximal anastomosis using Heartstring system did not show statistically significant benefit over aortic side clamping, the absence of embolic stroke may be a definite benefit which may be better defined through further studies over a larger cohort.