Outcome comparison of thoracic endovascular aortic repair performed outside versus inside proximal landing zone length recommendation

Objective: Success of thoracic endovascular aortic repair (TEVAR) relies heavily on the proximal landing zone (PLZ) sealing. Most instructions for use of thoracic endografts recommend a PLZ length of at least 2 cm. Because of the complex aortic anatomic features, TEVAR landing in zone 1 to zone 3 may not meet this requirement. The aim of this study was to examine whether 2-cm PLZ nonadherence was related to adverse outcomes after TEVAR. Methods: A retrospective review was performed of patients who underwent zone 1, zone 2, and zone 3 landing TEVAR at a single institution between November 2013 and October 2018. Preoperative and postoperative computed tomography angiography images were analyzed using three-dimensional reconstruction. The patients were categorized into two groups: PLZ >= 2 cm (adherence group) and PLZ <2 cm (nonadherence group). Collected data included patient and anatomic characteristics. Primary outcomes were type IA endoleak, retrograde dissection, and graft migration. Results: The cohort comprised 63 patients (18 in the adherence group and 45 in the nonadherence group) with a mean age of 53.3 +/- 20.6 years. Indications for TEVAR were blunt thoracic aortic injury (65.1%), thoracic aneurysm (23.8%), penetrating ulcer (9.5%), and type B dissection (1.6%). Mean PLZ length was significantly shorter for the nonadherence group (8 +/- 7 mm for the nonadherence group vs 34 +/- 15 mm for the adherence group; P < .0001). PLZ location (2 zone 1, 15 zone 2, 46 zone 3) and oversizing (19.4% +/- 8.3% for the adherence group; 20.3% +/- 10.2% for the nonadherence group; P = .7) were similar between the groups. The mean PLZ aortic diameter of the adherence group was significantly larger than that of the nonadherence group (29 +/- 5 mm for the adherence group; 25 +/- 5 mm for the nonadherence group; P = .004). Mean follow-up time was 126.7 days (range, 0-644 days) for the adherence group and 233.8 days (range, 0-1750 days) for the nonadherence group (P = .2). During the study period, no primary outcome was observed in the adherence group, whereas 12 adverse events occurred in 10 patients in the nonadherence group (type IA endoleak, n = 10; graft migration, n = 1; retrograde dissection, n = 1). Of 10 type IA endoleaks, five were immediate (4 resolved spontaneously, 1 remained persistent) and five were delayed (1 resolved spontaneously, 1 remained persistent, 1 ruptured causing death, 2 required total arch replacement). Conclusions: Achieving recommended sealing zone of 2-cm centerline length is paramount to avoid device-related adverse outcomes. We recommend careful surveillance in patients undergoing urgent TEVAR with <2-cm PLZ.