T-branch by partial deployment technique in the endovascular repair of complex aortic and thoracoabdominal aneurysms with narrow or severe angulated para-visceral aorta.

Introduction/aim: The partial deployment technique (PDT) is an unconventional option of T-branch deployment to allow target arteries (TAs) cannulation/stenting from the upper arm access, in case of narrow (NPA: <25mm) or severely angulated (APA: >60°) aorta. Aim of this study was to report outcomes of the endovascular repair of complex aortic (c-AAAs) and thoracoabdominal (TAAAs) aneurysms by T-branch and PDT.

Methods: All consecutive patients underwent urgent endovascular repair of c-AAAs and TAAAs by T-branch (Cook-Medical, Bloomington, IN, US) and PDT from 2021 to 2023 were analyzed. Technical success (TS), 30-days mortality, TAs-instability within 30-days and 1-year as well as reinterventions were assessed as primary endpoints. Time of intraoperative pelvic/lower limb ischemia, spinal cord ischemia (SCI) and perioperative stroke were assessed as secondary endpoints.

Results: Thirty-three cases were analyzed. There were 6(18%) type I endoleaks in failed EVAR, 9(28%) juxta/para-renal aneurysms, 6(18%) post-dissection and 12(36%) degenerative TAAAs, respectively. The median para-visceral aortic lumen diameter was 23(IQR:19-27) mm and 10(30%) cases had APA. Out of 128 TAs, 111(87%) were cannulated/stented with distally captured aortic graft. The median time of pelvic/lower limb ischemia was 120 (IQR:90-150) minutes. TS was achieved in all patients. One (3%) patient suffered SCI and there were no cases of stroke. An asymptomatic renal artery occlusion was detected at postoperative imaging which was recanalized by thrombus-aspiration/relining. This was the only case of TAs-instability (1/128-0.8%) and reintervention (1/33-3%) within 30-day. Two (6%) patients died within 30-days. Median follow-up was 14(IQR:6-22) months. One (3%) case of bilateral renal artery occlusion occurred at 6-months. No superior mesenteric artery or celiac trunk events occurred, with an overall TAs-instability rate of 2% (3/128). Eighteen (55%) patients completed the radiological follow-up at 1-year with no new case of TAs-instability. Freedom from TAs-instability was 91% at 1-year.

Conclusion: T-branch by PDT seems to be safe and effective in the management of c-AAAs/TAAAs with NPA or APA. Results were satisfactory in terms of TS and mid-term TAs-instability, suggesting a possible enlargement of the anatomical feasibility criteria for outer branches in urgent cases.