**1. Introduction**

Neurological complications are the most common complications after coronary artery bypass grafting (CABG) with high mortality rate [1]. With the advantages of off-pump coronary artery bypass grafting (OPCABG), the proportion of OPCABG in CABG is increasing continuously. The use of OPCABG procedures peaked in 2002 (23%) and in 2008 (21%), followed by a progressive decline in OPCABG frequency to 17% by 2012 [2].OPCABG is regarded as a milestone in the development of CABG and the most effective minimally invasive surgery as it avoids the injury of multiple organ malfunction caused by cardiopulmonary bypass [3–4]. With the widespread of OPCABG, the incidence of postoperative neurological complications caused by aortic intubation decreased significantly [5–6]. Nevertheless, great saphenous vein is still the main material for most CABG. It has been nearly half a century since the continuous suture of the great saphenous vein-aortic anastomosis in the coronary artery bypass grafting required the operation of surgical clamping and perforation on the ascending aorta, which may lead to potential plaque detachment and cause

postoperative neurological complications [4]. Calcification of ascending aorta is an independent risk factor for cerebrovascular events after OPCABG, especially for postoperative stroke [3]. Therefore, careful exploration and accurate management of the ascending aorta are important. Traditional proximal anastomosis in OPCABG requires partial blocking of ascending aorta with side wall clamp; however, for patients with ascending aortic disease (e.g., serious ascending aorta atherosclerosis), connective tissue disease-related arteritis and syphilitic arteritis, the mechanical damage of aortic intima may be caused by the lateral cutting force produced by side wall clamp, which may lead to the rupture, dissection of aorta, rupture and detachment of atherosclerotic plaque and other serious perioperative complications. In recent years, a large number of auxiliary devices for proximal anastomosis of grafts have emerged, which can complete great saphenous vein-aortic anastomosis safely, simply, reliably and quickly without clamping ascending aorta, including commercial proximal anastomosis auxiliary device (Enclose, Heartstring, etc.) [7–9], original auxiliary device (urethra catheter-water sac) or no-clamp surgical techniques for proximal anastomosis [10–12]. This chapter will mainly introduce the anastomotic method of the auxiliary device of proximal anastomose.
