CT血管造影を用いたhigh flow bypassにおけるgraft routeの検討

抄録

Because the passage of a graft for a high flow bypass between an anastomosis site of the cervical external carotid artery to the temporal base is made in a blind manner, knowledge of anatomy is essential for a surgeon to perform the high-flow bypass. A radial artery graft provides better long-term patency but shorter available length in comparison to a saphenous vein graft. The radial artery graft, therefore, demands a shorter graft route. The purposes of this study were to confirm a relationship among a graft, surrounding muscles, vessels, and bones on a source image of a computed tomography angiogram (CTASI), and to investigate the shortest graft route. Fourteen patients undergoing high flow bypass for internal carotid artery aneurysms between 2008 and 2015, with a graft demonstrated on a CTASI, were evaluated. The following four types of graft routes including routes 1-3, which were submandibular routes, were classified on CTASIs. Route 1: A graft passes through the medial space to both the posterior belli of the digastric muscle and the stylohyoid muscle. Route 2: A graft goes up to the lateral space to the digastric muscle and turns to the medial space to the stylohyoid muscle. Route 3: A graft goes up to the lateral space to both the digastric muscle and the stylohyoid muscle. Route 4: A subcutaneous route lateral to the mandible. Measurement of the graft length on CTASIs revealed that the route 3 was the shortest among the four routes. The graft in route 3, however, was so close to the external carotid artery between the styloid process and the mandible on a CTASI that a passage tube for the graft could have disturbed the blood flow in the superficial temporal artery, which was used as an assist bypass. In consideration of the limitation of an available graft length, a submandibular route lateral to both the digastric and stylohyoid muscles was the most suitable for high flow bypass using a radial artery graft. Pre-operative observation of the graft routes on CTASIs seems to be useful to prepare for the procedure.