# Suitability of Single-Branched Thoracic Endografts for the Treatment of Acute Type B Aortic Dissection—An Anatomical Feasibility and Comparative Study

## TL;DR

This study assesses how well two types of stent grafts can be used to treat aortic dissections by analyzing their anatomical suitability and the need for additional procedures.

## Contribution

The study introduces a method to determine the minimal number of stent configurations needed for off-the-shelf use in treating aortic dissections.

## Key findings

- 82% of cases were suitable for the Castor CMD with 74 configurations, but many required additional procedures.
- The TBE had 22% off-the-shelf suitability, increasing to 78% with adjunctive procedures.
- Short landing zones and atypical arch anatomies were the main reasons for exclusion in Castor cases.

## Abstract

Objectives: This study evaluated the anatomical suitability of two single-branched thoracic stent grafts—the Castor (Endovastec, China) and the Thoracic Branch Endoprosthesis (TBE, Gore, USA)—for proximal landing in aortic arch zone 2, including the left subclavian artery (LSA), in patients with acute type B aortic dissection (TBAD). While the TBE is currently available as an off-the-shelf device (26 main bodies, 8 branch configurations), the study also aimed to define the minimal number of configurations needed to treat most patients. The same approach was applied to the Castor stent graft, currently only available as a custom-made device (CMD), to assess its potential for off-the-shelf adaptation. Methods: A retrospective analysis was performed on computed tomographic angiographies of TBAD patients treated between 2004 and 2023. Exclusion criteria included type A or non-A-non-B dissections, isolated abdominal dissections, intramural hematomas, and lack of consent. Morphometric measurements were conducted using centerline analysis software. Suitability was defined per manufacturers’ criteria and reported with 95% confidence intervals. Results: Among 100 TBAD cases, 82% (95% CI: 73.3–88.3%) were suitable for the Castor CMD with 74 configurations. Main causes of exclusion were short landing zones and atypical arch anatomies. With adjunctive procedures, 13 Castor configurations covered all morphologies; 34% could be treated off-the-shelf, and 48% required additional interventions. For the TBE, off-the-shelf suitability was 22%, increasing to 78% with adjunctive procedures (six main bodies, five branches). Conclusions: Both stent grafts are promising for proximal extension in TBAD. Reduced configuration availability necessitates more adjunctive procedures, impacting efficiency and cost.