Outcomes of directional branches using self-expandable or balloon-expandable stent grafts during endovascular repair of thoracoabdominal aortic aneurysms

Objective: The objective of this study was to evaluate outcomes of directional branches using self-expandable stent grafts (SESGs) or balloon-expandable stent grafts (BESGs) during fenestrated-branched endovascular aneurysm repair of thoracoabdominal aortic aneurysms. Methods: Patients treated by fenestrated-branched endovascular aneurysm repair were enrolled in a prospective study from 2014 to 2018. We included in the analysis patients who had target vessels incorporated by directional branches using either SESG (Fluency [Bard, Covington Ga] or Gore Viabahn [W. L. Gore & Associates, Flagstaff, Ariz]) or BESG (Gore VBX). Target artery instability (TAI) was defined by a composite of any stent stenosis, separation, or type IC or type IIIC endoleak requiring reintervention and stent occlusion, aneurysm rupture, or death due to target artery complication. End points included technical success, target artery patency, freedom from TAI, freedom from type IC or type IIIC endoleak, and freedom from target artery reintervention. Results: There were 126 patients (61% male; mean age, 73 +/- 8 years) included in the study. A total of 335 renal-mesenteric arteries were targeted by directional branches using SESGs in 62 patients and 176 arteries or BESGs in 54 patients and 159 arteries. Patients in both groups had similar thoracoabdominal aortic aneurysm classification and aneurysm and target artery diameter, but SESG patients had significantly (P < .05) shorter stent length (-7 mm) and larger stent diameter (+1 mm) and more often had adjunctive bare-metal stents (72% vs 15%). Technical success was achieved in 99% of patients, with one 30-day death (0.7%). Mean follow-up was significantly longer among patients treated by SESGs compared with BESGs (23 +/- 12 months vs 8 +/- 8months; P < .0001). TAI occurred in 27 directional branches (8%), including 11 type IC endoleaks (2 SESGs, 9 BESGs), 10 stenoses (3 SESGs, 7 BESGs), 4 occlusions (3 SESGs, 1 BESGs), 4 type IIIC endoleaks (2 SESGs, 2 BESGs), and 1 stent separation (SESG), resulting in 20 target artery reinterventions in 16 patients (5 SESGs and 11 BESGs). At 1 year, SESGs had higher primary patency (97% +/- 2% vs 96% +/- 2%; P = .004), freedom from TAI (96% +/- 2% vs 88% +/- 3%; P < .0001), freedom from type IC or type IIIC endoleaks (98% +/- 1% vs 92% +/- 3%; P = .0004), and freedom from target artery reinterventions (98% +/- 1% vs 88% +/- 4%; P < .0001) compared with BESGs. There was no difference in secondary patency for SESGs and BESGs (98% +/- 1% vs 99% +/- 1%; P = .75). Factors associated with TAI were large stent diameter (odds ratio, 0.6; P < .0001) and use of VBX stent graft (odds ratio, 6.5; P < .0001). Conclusions: Directional branches were associated with high technical success and low rates of stent occlusion, independent of stent type. However, primary patency, freedom from TAI, and freedom from type IC or type IIIC endoleaks was lower for BESGs compared with SESGs.