IMAGING EXPERIENCE OF TYPE II HYBRID AORTIC ARCH REPAIR: LESSONS LEARNT FROM 6 YEARS OF ZONE 0 LANDING AND EVOLUTION TO ZONE 2 ARCH REPAIR

Abstract

Single stage hybrid aortic arch repair is a novel technique advocated for management of diffuse thoracic aortic pathology. Type II hybrid aortic repair involves surgical replacement of the ascending aorta with a Dacron graft, proximalization of arch vessels by debranching and Zone 0 stent graft deployment into the Dacron ascending aortic graft. We describe our completed experience with this technique, lessons learnt and reasons for evolution to a Zone 2 arch replacement technique. This single centre retrospective study includes 23 consecutive patients (65% male) who underwent type II hybrid arch replacement with a 4 branch Bavaria graft and Zone 0 endovascular stent graft placement, from November 2008 to July 2014. Follow up imaging was performed as per a pre-determined protocol. Imaging was reviewed by a dedicated cardiovascular radiologist to evaluate early and late outcomes and complications. Indications included aortic dissection (n=13), aortic aneurysm (n=9),and penetrating atherosclerotic ulcer (n=1), all involving the ascending aorta, arch and descending thoracic aorta. There was 1 intra-operative death. One patient was lost to follow up after 12 months. Mean imaging follow-up was 33 months (Range 4 to 72 months). One third of patients had mean follow up greater than 4.5 years. Three patients required 4 re-interventions for proximal landing zone complications -stent graft buckling (n=1), graft migration (n=1) and persistent Type 1a endoleak (n=2). There was no stent graft fracture. Proximal stent graft bird beaking within Zone 0 was seen along the lesser curve of the Dacron graft in 15 patients, 4 of which caused greater than 2 cm non-apposition. At 6 year clinical follow up there was no aortic rupture or late mortality. Perioperative and midterm survival with Hybrid Type II technique appears to be favourable. However, current generation of endografts deployed in Zone 0 have limitations in their ability to conform to the double curve of the ascending aorta, arch and descending thoracic aorta. Based on proximal landing zone complications and non-ideal apposition in the ascending aortic graft, we have moved towards extension of the surgical graft into Zone 2 of the arch with creation of an idealized Dacron landing zone for the stent graft that does not involve a double curve.View Large Image Figure ViewerDownload (PPT)