Characterization of visceral branch geometry in a four-branch off-the-shelf device for endovascular repair of paravisceral and thoracoabdominal aortic aneurysms.

BACKGROUND

This study aims to evaluate visceral branch geometry, including angulation, tortuosity, and diameter, of the GORE EXCLUDER thoracoabdominal branch endoprosthesis (TAMBE) in real-world utilization.

METHODS

All patients were identified and treated with TAMBE from June 2024 to June 2025 at a single institution. Using the first postoperative computed tomography scan, branch geometry was analyzed with three-dimensional reconstructive software including multiplanar reformats and centerline imaging. Per published guidance, centerline branch length (length 1, L1) was defined as the centerline distance from the distal edge of the portal to the end of the branch, including any covered stent but not including distal extension with an uncovered self-expanding stent. Direct length (length 2, L2) was defined as the direct distance between those two points. Tortuosity index was calculated as the ratio of L1/L2. Branch angle was measured between the portal and a line tangential to the distal end point of the branch. Branch diameter was measured at the distal end point of the stent. We used paired t-test for between-branch comparisons and two-sample t-test for comparisons by sex and between complex abdominal aortic aneurysm and thoracoabdominal aortic aneurysm.

RESULTS

A total of 29 patients were treated with TAMBE during the study period. The majority of patients were male (n = 18, 62.1%) and white (n = 27, 93.1%). The mean age was 72.6 ± 7.2 years (range, 51-81 years). A total of 25 patients had postoperative computed tomography available for analysis, with 93 visceral branches analyzed (celiac artery [CA]: n = 20, superior mesenteric artery: n = 25, right renal artery [RRA]: n = 24, and left renal artery [LRA]: n = 24). Pairwise comparisons revealed significant differences between the CA, superior mesenteric artery, and renal arteries in terms of all geometric parameters including L1, L2, tortuosity index, and distal branch diameter, but no significant difference between RRA and LRA. Between-group comparisons showed a greater degree of CA angulation in females (142 ± 23° in females vs 113 ± 23° in males, P = .02) and significantly greater distal renal artery branch diameters in males (RRA: 6.2 ± 0.6 mm in males, 5.4 ± 0.6 mm in females, P = .02; LRA: 6.2 ± 0.5 mm in males, 5.7 ± 0.5 mm in females, P = .03). Between-group comparisons for the remaining branch parameters did not show a significant difference.

CONCLUSIONS

We demonstrate that geometric parameters of visceral branches in TAMBE vary significantly, whereas differences in terms of sex and aneurysm extent are less common. Evaluating the impact of these differences on long-term branch outcomes may help guide device selection and optimize patient outcomes.