Evaluation of Endosuturing During Aortic Stent Graft Placement: In-vivo Analysis and Preclinical Results

Background: Stent graft migration following endovascular aneurysm repair has been reported with all currently available devices and can result in type I endoleaks and aneurysm rupture. Standard surgical anastamosis with suturing through the adventia requires a significantly greater force to disrupt compared to any current proximal endovascular device fixation. The purpose of this study was to evaluate the safety, technique and effectiveness of the EndoRefix clip to create a surgical anastomosis in combination with an aortic stent graft during endovascular aneurysm repair.
Methods: Six ovine were treated with an Aorfix Dacron endograft (Lombard Medical, Oxfordshire, England) in the thoracic aorta. Each animal received a single stent graft with placement of 6 EndoRefix clips placed proximally and 6 clips placed distally to simulate a proximal and distal surgical anastamosis. The EndoRefix is a repositionable nitinol fixation stapler. It delivers a repositionable nitinol clip that penetrates both the stent graft and all layers of the aortic wall including the adventia.
Results: There were no morbidities or mortalities associated with implantation. Mean time for creation of a proximal and distal anastomosis was 22 min (range, 17 -31 minutes). All clips were successfully deployed at the time of initial implantation.. Following placement of the stent graft and the endoclips the animals were survived for 35 days. Pathological examination of the treated segment was then performed. 64/72 (89%) of the staple arms fully penetrated the stent graft and the aortic wall. There were no graft related abnormalities. At 35 days there was no evidence of migration. Endothelization of the luminal portion of the endoclip was present on all clips. All implant sites were scored as normal by an independent pathologist with no damage to surrounding tissues. The stent graft was found to be securely attached to the aortic wall. In 68/72 (94%) the staples were placed within 10 mm of the proximal or distal portion of the stent graft.
Conclusions: Preclinical evaluation of The EndoRefix stapling device was found to be safe, technically feasible and effective in creating an endovascular surgical anastamosis that can be performed for the rapid suturing of an aortic endograft through the adventia without damage to surrounding tissues.