Effect of proximal fixation length on complications after endovascular repair of type B aortic dissection

Abstract

ObjectiveWe evaluated the effect of the achieved proximal seal length on the outcomes after endovascular repair of acute type B aortic dissection (aTBAD). MethodsA post hoc analysis was performed using data from two prospective, multicenter investigational studies of the Zenith Dissection Endovascular System (STABLE I and II). Patients treated for aTBAD within 14 days of symptom onset were included if complete preoperative and postoperative imaging data were available for review. The patients were divided into four groups according to the length of the achieved proximal seal according to the centerline imaging findings: ≥20 mm, ≥10 to <20 mm, ≥0 to <10 mm, and <0 mm. The outcomes stratified by the achieved proximal seal length were evaluated. All imaging findings were based on core laboratory analysis. ResultsA total of 110 patients were included in the present analysis; 51 were from STABLE I and 59 from STABLE II. Although the study protocol criteria required a ≥20 mm length of nondissected aorta distal to the left common carotid artery to serve as a proximal seal zone, an achieved proximal seal length of ≥20 mm was observed in only 19 of the 110 patients (17.3%) according to the location of stent-graft placement. After a mean follow-up duration of 41.6 ± 21 months, the cumulative rate of the composite device outcome (ie, proximal entry flow, retrograde dissection, transaortic growth, and stent-graft migration) was lowest in patients with an achieved proximal seal length of ≥20 mm (15.8%; 3 of 19). The cumulative rate increased as the seal length decreased (32.0% [8 of 25], 55.6% [20 of 36], and 60.0% [18 of 30] with a proximal seal length of ≥10 to <20 mm, ≥0 to <10 mm, and <0 mm, respectively; P < .01, Cochran-Armitage trend test). ConclusionsA clear inverse relationship was found between the proximal seal length achieved and associated adverse outcomes. This finding underscores the importance of landing the stent-graft in healthy, nondissected aorta to minimize the risk of complications and provide a durable repair in patients with aTBAD.