Highly flexible nitinol mesh to encase aortocoronary saphenous vein grafts: first clinical experiences and angiographic results nine months postoperatively

Abstract

Saphenous vein graft patency is frequently limited by degeneration. Experimental studies have indicated that rigid external support of venous grafts by a flexible, tubular nitinol mesh may improve graft patency. The study presented was part of a prospective, randomized, multicenter first-in-man trial investigating the safety and effectiveness of nitinol-supported venous grafts in coronary artery bypass graft (CABG) surgery. From our clinic, 25 subjects with multivessel coronary artery disease requiring saphenous vein graft CABG of the right coronary artery (RCA) and the circumflex artery were entered into the trial. Subjects were randomized to receive a mesh-supported graft on one of these arteries; the other vessel received an untreated vein graft. Graft patency was assessed by coronary angiography nine months after surgery. The implantation of mesh grafts was simple and safe. In 10 cases, a nitinol mesh-supported venous graft was anastomosed to the circumflex artery and in 15 cases to the RCA. All patients survived the observation period. A total of 72% of the patients underwent control coronary angiography. The patency rate of mesh-supported grafts was 27.8% nine months postoperatively. Conventional vein grafts showed an 85.7% patency, and arterial grafts had a 100% patency. No complications directly related to the implantation of mesh-supported grafts were observed. The promising experimental results of mesh-supported venous grafts could not be reproduced in the study presented. A critical item seems to be correct selection of nitinol mesh diameter, the anastomotic method and fixation of the mesh tube to the venous graft.

A Randomized Trial of External Stenting for Saphenous Vein Grafts in Coronary Artery Bypass Grafting

“…However, limited clinical data has been published to date with such devices. Murphy et al (14) described 100% occlusion of externally stented SVGs at six months and Schoettler et al (15) reported a 72% occlusion rate at nine months. Recently, Rescigno et al (16) described 66.9% occlusion at 12 months of SVGs supported with nitinol mesh.…”

Inhibition of vein graft remodeling and neo-intimal formation using a cobalt chrome external support

“…Prior attempts to externally support vein grafts involved the use of fibrin glue and sutures to fixate the external support to the vein graft [15,16]. Experimental data have shown that the application of fibrin glue on the external surface of vein grafts lead to aneurysmal degeneration and excessive intimal hyperplasia which may have jeopardized vein graft patency [17][18].…”

“…Experimental data have shown that the application of fibrin glue on the external surface of vein grafts lead to aneurysmal degeneration and excessive intimal hyperplasia which may have jeopardized vein graft patency [17][18]. Recent clinical data showed that suturing and fixating an external support device to the anastomoses leads to early failure of vein grafts, most probably due to an acute constriction of the anastomosis site [15]. Application of the FRAME device does not require the use of fibrin glue or any other fixation mechanism postdeployment.…”

The Choice of Graft Conduits in Coronary Artery Bypass Grafting

“…Murphy et al reported 100% occlusion of external stented SVG at 6 months [69]. Schoetler et al reported that the patency rate of mesh-supported SVG was 27.8% at 9 months, whereas conventional SVG showed 85.7% patency [70]. Rescigno et al reported 66.9% occlusion at 12 months of SVG supported with nitinol mesh [71].…”