(PC020) Impact of Lumen Origin and Gap Distance on Target Artery Outcomes Following Fenestrated-Branched Endovascular Aortic Repair for Post-dissection Thoracoabdominal Aortic Aneurysms

Objectives: This study evaluated the role of target artery (TA) lumen origin and fenestration gap (FG) distance between endograft and aortic wall on TA outcomes following fenestrated-branched endovascular aortic repair (FBEVAR) for post-dissection thoracoabdominal aortic aneurysms (PD-TAAAs).

Methods: A multicenter review of prospectively and retrospectively collected data of patients undergoing FBEVAR for PD-TAAAs between 2013-2023 was performed. Lumen origin was retrospectively analyzed on pre-operative imaging studies and classified as true lumen (TL) only, false lumen (FL) only or true and false lumen. The FG distance was retrospectively measured on post-operative imaging studies and included as a linear variable. Primary outcome measures were freedom from TA instability stratified by TA lumen origin and device design.

Results: There were 605 patients treated with FBEVAR, of these 74 (12%) patients (77% male, mean age 67±10 years) were treated for PD-TAAAs (Table I). Company manufactured, patient-specific devices were utilized in 45 patients (61%), multibranch off-the-shelf device was utilized in 16 (22%) and PMEGs were utilized in 13 (18%). A total of 280 renal-mesenteric TAs were incorporated by 157 fenestrations (56%) and 123 (44%) directional branches (DBs), with a mean of 3.8±0.5 vessels per patient. TL target artery origin was identified in 200 TAs (71%), FL in 44 TAs (16%) and both true and false lumen in 36 TAs (13%). Technical success was achieved in 69 patients (93%), and was not affected by TA origin. Mean follow-up was 35±27 months. Freedom from TA instability at 4-years was not affected by lumen origin, including when stratified by fenestrations (87%, 78%, and 75% for TL, FL, and both TL and FL origins p=.27) and DBs (84%, 53%, and 67% for TL, FL, and both TL and FL origins p=.17). Similarly, there were no significant differences in TA instability when comparing device designs (p=.58) or when comparing fenestrations and DBs (p=.97). Increased FG distance was associated with higher rates of TA instability (hazard ratio, 1.10; 95% confidence interval, 1.01-1.19). Overall survival and freedom from aortic related mortality at four-years were 52% and 98% for the entire cohort, with no changes associated with TA origin.

Conclusions: False lumen target artery origin was not associated with increased rates of target artery instability or technical failure in patients undergoing FBEVAR for PD-TAAAs and thus, attempts should be made to incorporate all renal-mesenteric vessels when appropriate. Importantly, device design was not a predictor of target artery instability and similar outcomes were obtained with different stent-graft platforms.