Anatomic Feasibility of Off-the-shelf Thoracic Single Side-branched Endograft in Patients With Blunt Traumatic Thoracic Aortic Injury

Abstract

The advent of thoracic single side-branched endograft (TSSBE) provides a treatment option to obviate the need for open cervical debranching of the left subclavian artery (LSA), thereby enabling total endovascular incorporation of the LSA during thoracic endovascular aortic repair (TEVAR). In a previous study in patients with type B aortic dissection who required zone 2 TEVAR, anatomic feasibility of this device has been demonstrated to range between 28% and 35%, suggesting limited applicability of currently available designs. The objective of this study was twofold: (1) to evaluate the anatomic feasibility of TSSBE in an unselected population of blunt traumatic thoracic aortic injury (BTTAI) patients who would require LSA revascularization; and (2) to describe the anatomic characteristics of the aortic arch branches that can be used to improve future device design. A retrospective review was performed on BTTAI patients who underwent TEVAR at a single institution between November 2013 and October 2018. Preoperative computed tomography angiography images were analyzed using three-dimensional reconstruction to quantify aortic diameter, distance and arc length between branch vessels, and target side branch vessel diameter and length. We calculated the percentage of patients that met all anatomic requirements for TSSBE proposed by investigational protocols that have been published, and plotted each branch vessel in relation to the left common carotid artery in cases of normal aortic arch and the innominate artery in cases of bovine aortic arch. There were 41 patients (63% men; median age, 39 years [range, 23-88 years]; 68% normal aortic arch pattern, 32% bovine aortic arch pattern) with BTTAI considered potential candidates for TSSBE. Of these, 13 (7 bovine aortic arch, 6 normal aortic arch; 31.7%) met all proposed anatomic requirements for TSSBE: appropriate aortic diameter, LSA diameter, and LSA length to its first branch were observed in 100%, 95%, 66% of the patients, respectively. Insufficient distance between arch branch vessels, observed in 41%, was the most common exclusionary criterion. Figs 1 and 2 depict the absolute positions of individual branch vessels relative to the left common carotid artery and to the innominate artery in the 0 axis, respectively. Despite numerous potential advantages of TSSBE, only 32% of patients with BTTAI requiring LSA revascularization met all the anatomic requirements, justifying the need for additional designs. Improved characterization and mapping of the aortic arch branches will improve future device design and application.Fig 2View Large Image Figure ViewerDownload Hi-res image Download (PPT)