Anatomic feasibility of the investigational GORE EXCLUDER Thoracoabdominal Branch Endoprosthesis (TAMBE), off-the-shelf multibranched endograft for the treatment of pararenal and thoracoabdominal aortic aneurysms

Objective: The objective of this study was to evaluate the proportion of pararenal aortic aneurysms and thoracoabdominal aortic aneurysms (TAAAs) that could theoretically be treated with the investigational GORE EXCLUDER Thoracoabdominal Branch Endoprosthesis (TAMBE; W. L. Gore & Associates, Flagstaff, Ariz) off-the-shelf multibranched endograft. Methods: The preoperative computed tomography scans of patients with pararenal aortic aneurysms and TAAAs treated at a single institution between 2007 and 2017 were reviewed. This cohort included both open and endovascular repairs performed in either elective or urgent/emergent settings. These studies were included in a retrospective feasibility study to verify anatomic feasibility of the TAMBE graft (with four antegrade portals) employed within the manufacturer's investigational instructions for use during the U.S. pivotal trial. The patient cohort was divided into two groups: extended thoracoabdominal aneurysm (E-TAA)—extent I, II, and III TAAA; and limited pararenal and thoracoabdominal aneurysm (L-TAA)—pararenal aortic aneurysm and extent IV TAAA. The anatomic factors determining the overall theoretical feasibility were further divided into three groups: vascular access feasibility, aortic feasibility, and visceral vessel feasibility. Results: Computed tomography scans of 227 patients with degenerative aneurysms were analyzed, 166 with E-TAA and 61 with L-TAA. In the L-TAA group, 49% of the cases could have been treated with the TAMBE endograft alone; access feasibility was 85%, aortic feasibility 74%, and visceral vessel feasibility 72%. In the E-TAA group, only 23% of the cases could have been treated with a TAMBE combined with a GORE CTAG proximal thoracic stent graft; access feasibility was 79%, aortic feasibility 48%, and visceral vessel feasibility 63%. The different feasibility rate was related to a difference in aortic feasibility between L-TAA and E-TAA (74% vs 48%; P =.0008) because of the lack of a dedicated tapered thoracic component. Conclusions: The TAMBE multibranched endograft can theoretically be employed in half of an all-comers cohort of patients with degenerative L-TAA. Development of a dedicated tapered thoracic component is warranted to increase the feasibility for E-TAA, and comparative studies are required to investigate differences with other available off-the-shelf stent grafts.