Treatment and outcomes of type IIIb endoleaks affecting the main fenestrated-branched aortic stent graft component among patients treated for complex abdominal and thoracoabdominal aortic aneurysms.

OBJECTIVE

Type IIIb endoleak (T3bE) owing to fabric tears or integrity issues is infrequent, but has been poorly described among patients undergoing fenestrated-branched endovascular aortic repair (FB-EVAR). This study aimed to describe the incidence, management, and outcomes of T3bE after FB-EVAR for the treatment of complex abdominal aortic aneurysms (CAAAs) and thoracoabdominal aortic aneurysms (TAAAs).

METHODS

Clinical data, imaging, and outcomes of consecutive patients enrolled in prospective, nonrandomized physician-sponsored investigational device exemption studies evaluating company-manufactured devices for FB-EVAR at three centers were reviewed from 2013 to 2024. Patients with unequivocal diagnosis of T3bE affecting the main fenestrated-branched aortic device component, confirmed by contrast-enhanced ultrasound examination, standard or dynamic computed tomography angiography (CTA), and/or diagnostic angiography, were included. The primary end point was the cumulative incidence of T3bE. Secondary end points included treatment approaches, mortality, major adverse events, secondary interventions, and aneurysm rupture.

RESULTS

A total of 717 patients (69% male; mean age, 74 ± 8 years old) were treated by FB-EVAR in the two centers. After a median follow-up of 37 months (interquartile range [IQR], 25-40 months), eight patients (1.1%) had unequivocal diagnosis of T3bE affecting the main component of a fenestrated-branched device. Cumulative incidence of T3bE at 3 and 5 years was 1.1% (95% confidence interval, 0.0%-2.2%) and 2.4% (95% confidence interval, 0.6%-4.3%), respectively. All patients had prior imaging showing no T3bE. Surveillance imaging with a final diagnosis of T3bE was established by angiography in three patients, contrast-enhanced ultrasound examination in two, dynamic CTA in two, and CTA in one. Of the eight patients, seven underwent endovascular repair with redo fenestrated-branch device in three, and parallel stent graft, cuff extension, or endovascular plug/coils in one each. Seven secondary interventions successfully resolved the T3bE with one patient presenting with an aneurysm rupture leading to mortality. One patient was managed conservatively with clinical surveillance and had spontaneous resolution of the endoleak. The overall median follow-up was 55 months (IQR, 42-62 months), and the median follow-up after T3bE reintervention was 20 months (IQR, 5-28 months).

CONCLUSIONS

T3bEs from fabric tears or integrity issues are uncommon after FB-EVAR, but pose diagnostic and treatment challenges, particularly when the affected segment involves fenestrations and directional branches. Redo endovascular repair is effective in selected patients. Persistent leaks may lead to aneurysm sac expansion and rupture, emphasizing the need for vigilant surveillance and timely intervention.