The aortic side partial clamp is usually placed after finishing the distal coronary artery anastomosis and aortic declamping with heart beating. The partial clamp is placed on the anterior face of the ascending aorta, and a hole is made with a puncher following a small cut with a spit knife on the ridge of the partially clamped aorta to avoid aorta injury. Anastomosis for the circumflex artery should be made slightly toward the left side of the wall to create proximal anastomosis rising from the ascending aorta. Proximal anastomosis can be set on the anterior aspect, making the graft run parallel to the aorta, or it can pass down toward the right-sided space of the right atrium. The size of the puncher is usually 4.5 mm for vein grafts and 3.5 mm for free ITA graft or radial artery graft. A hole that is too big for the graft risks stenosis at the heel side and excessive tension on the graft on the toe side. Blood pressure should be kept low by lowering the perfusion flow when using a heart-lung machine or by administration of vasodilator to avoid aortic injury or dissection. At the same time, compression on the carotid arteries by the anesthesiologist might help debris from the clamp side escape to proceed into the arch branches.

The aorta no-touch technique might carry a low risk of cerebral embolization for patients with some degree of atherosclerosis on the aorta. Some surgeons have recommended the usage of anastomosis devices [11–13, 17–19, 22–25]. However, should these aorta no-touch techniques or anastomosis devices be used in all patients? Is there any evidence that these techniques make any difference regarding cerebral infarction in patients with a normal aorta? Yamaguchi reported that when intraoperative epiaortic ultrasonography showed no atherosclerotic change on the ascending aorta, simple aortic side clamping was not associated with any significant increase in cerebral infarctions [9]. However, presence of some degree of atherosclerotic change, fragile plaque, thickening, or debris should be taken into consideration and other techniques applied to avoid manipulation of the aorta.

As the first device for proximal anastomosis available in Japan, the aortic connector was introduced in 2002. Results of short- and long-term studies on patency rates for this device are ambiguous [11–13]. Farhat reported histological damage to saphenous vein grafts with this device [14], which was withdrawn from use in Japan in 2006.

The PAS-Port system was introduced in 2004 in Japan and has been used under specific conditions. It can be used for cases showing severe atherosclerosis on the ascending aorta with one spot where the aortic wall is suitably thin and smooth. The stent anchoring the vein graft to the aorta is placed external to graft, whereas the stent was inside the vein graft in the symmetry aortic connector. Although Izutani reported one case of ostial stenosis at 4 months postoperatively [15], this structure may decrease the possibility of thrombosis inside the graft and is morphologically acceptable according to Kawasaki [16]. Many groups have reported better results after clampless OPCAB using the PAS-Port system compared with conventional CABG [17–19] (Fig. 17.2).

These two anastomosis devices allowed automatic connection of the grafts on the aorta. However, some concerns have been raised regarding the quality of anastomosis, due to the need for metal stents for anchoring. The following are two new anastomosis devices that enable hand-sewn anastomosis:

The Heartstring was introduced to Japan in 2003. A hole is made with the original punch, then pressure is placed over the hole with a finger to stop the bleeding, and the sealing umbrella is inserted into the aorta. Hemostasis is achieved by blood pressure pushing the umbrella against the aorta wall [20]. Once hemostasis is obtained, anastomosis can be completed with a standard hand-sewn technique not only for the saphenous vein but also for radial artery grafts. After completing hand-sewn sutures, the sealing string comes out of the suture line as a single string. Sometimes bleeding cannot be completely controlled, but in such cases, use of the blower helps to make the hole bloodless. Thourani reported the Heartstring proximal anastomotic device could be safely used with all grades of aortic atherosclerosis, especially with moderately diseased aorta [21]. Stroke has been reported to occur with usage of this device in OPCAB [22–25] (Fig. 17.3).

This is another manual proximal anastomosis device that enables the surgeon to perform proximal hand-sewn anastomosis without side clamping. The lower jaw of the device is inserted into the aorta through a small hole made by a 14-G needle 2 cm above the anastomosis point. The jaw is advanced toward the point of anastomosis. The membrane of the lower jaw is opened, and the upper jaw is lowered toward the aortic wall to compress the lower jaw onto the inside of the aorta. A small incision is made in the aorta and excess aortic tissue is removed using the 3.5-mm aortic punch. Proximal anastomosis can be performed in the usual fashion. An overly deep bite might tear the membrane. After the first anastomosis is finished, the device can be repositioned for the next. This technique is not a real aorta no-touch technique. Care should be taken to avoid atherosclerotic sites for the needle hole or anastomosis position using epiaortic ultrasonography. Many reports have shown good results using this device, which is popular in Japan [25–28] (Fig. 17.4).