Anatomical Analysis and Feasibility Study of Next-Generation Fenestrated or Branched Stent-Grafts for the Treatment of Arch Aneurysms.

To analyze the anatomical characteristics of arch aneurysms and evaluate the anatomical feasibility of 4 next-generation stent-grafts with either branched or fenestrated configurations. A retrospective analysis was conducted of 213 patients (mean age 75.0±7.1 years; 179 men) with arch aneurysms treated using total arch replacement or zone 0 or 1 thoracic endovascular aortic repair (TEVAR) from 2007 to 2017 at 2 Japanese hospitals. Anatomical analyses were performed using the centerline of flow technique on a 3-dimensional workstation. The anatomical feasibility of the Zenith A-branch, TAG Thoracic Branch Endoprosthesis (TBE), Terumo Aortic Relay Plus Double Branched (DB), and fenestrated Najuta stent-grafts were evaluated based on the instructions for use (IFU). The mean lengths from the sinotubular junction (STJ) to the innominate artery (IA) and from the IA to the left common carotid artery were 114.9±15.9 and 12.8±5.6 mm, respectively. The mean aortic diameters at the STJ and IA were 31.3±3.4 and 34.1±5.3 mm, respectively. In terms of feasibility, 5.2% of patients were within the Zenith A-branch IFU, 40.8% for the TAG TBE, 24.9% for the Relay Plus DB, and 13.6% for the Najuta. Significant (>50% circumference) thrombus/calcification at the sealing zone affected nearly half of the patients, but there is currently no standardized definition or evaluation method for "significant" thrombus/calcification. Only 5% to 41% of arch aneurysm patients are anatomically suitable for TEVAR using any one of the next-generation branched or fenestrated stent-grafts. Furthermore, a definitive method of evaluating the thrombus/calcification burden needs to be established in future IFU.