Assessing the anatomic applicability of the multibranched endovascular repair of thoracoabdominal aortic aneurysm technique

Abstract

Background: Multibranched endovascular aneurysm repair (MBEVAR) has the potential to lower the morbidity and mortality rates of thoracoabdominal aneurysm repair, but the applicability of the technique is unknown. Our aim was to estimate the prevalence of anatomic suitability for MBEVAR.

Methods: Retrospective review of patients referred for a prospective trial of MBEVAR between November 2005 and July 2012. Anatomic suitability was assessed on three-dimensional computed tomography scan reconstructions according to the current criteria for a custom-made stent graft or a fixed, off-the-shelf stent graft in both standard (22F) and low-profile (18F) delivery systems.

Results: A total of 250 contrast-enhanced computed tomography scans were reviewed, 49 of which were excluded due to inadequate aneurysm size. Of 201 candidates for repair, 149 (74%) were men and 86 (43%) had Crawford classification type IV/paravisceral aneurysms; 109 (58%) were anatomically suitable for a single-stage repair with a custom-made, low-profile stent graft. Another 58 (29%) could have been made suitable for MBEVAR with an adjunct procedure, including angiogram with visceral or renal artery stenting (n = 23), carotid-subclavian bypass (n = 5), or iliac bypass for device insertion (n = 17), or to preserve internal iliac artery flow because of an iliac aneurysm (n = 9), or dissection (n = 8). There was no association between suitability and gender, aneurysm diameter, or type. However, women were significantly more likely to need a conduit or low-profile device (P = .003). Patients with type B aortic dissections were significantly less likely to have anatomy suitable for repair (P = .035) and more likely to require a multistage repair. Thirty-four patients would have been unsuitable for repair because of renal artery anatomy (n = 14), visceral artery anatomy (n = 4), lack of a proximal landing zone due to an arch aneurysm (n = 7), or inadequate access arteries (n = 9). The low-profile device increased the number of patients who would have been suitable for a single-stage repair by 16. The off-the-shelf graft has the advantage of a faster assessment-to-treatment time, but only 64 patients would have been suitable for a single-stage repair and another 30 could have been made suitable with an adjunct procedure.

Conclusions: Most patients would have been suitable or could have been made suitable for a thoracoabdominal stent graft using current anatomic criteria. The applicability of MBEVAR will continue to change as the experience with the technique grows and devices evolve, as evidenced by the potential reduction in iliac bypasses after the introduction of a low-profile device and the ability to treat symptomatic or urgent patients with the off-the-shelf device.