Distal landing zone optimization before endovascular repair of aortic dissection

Abstract

Background: The general goals of endovascular management in chronic distal thoracic aortic dissection are optimizing the true lumen, maintaining branch patency, and promoting false lumen (FL) thrombosis. Distal seal can be challenging in chronic distal thoracic aortic dissection due to the well-established secondary fenestrations and fibrotic septum. We describe our approach of distal landing zone optimization (DLZO) to enable full-diameter contact of the distal endoprosthesis.

Materials and methods: Our experience includes 19 procedures in 16 patients (12 male, age 68 ± 8 years) between May 2014 and November 2017. A history of previous ascending repair for type A dissection was present in 8 patients. Treatment indication was enlarging aneurysm in all subjects, and 4 patients had associated chronic visceral or distal ischemia. Point septal fenestrations were expanded by serial balloon dilation and/or wire-pull approaches. Balloon molding was used to ensure complete endograft apposition and FL collapse.

Results: One death occurred due to aortic perforation during wire-pull fenestration in a patient with heavily calcified and angulated aorta. The remaining procedures were accomplished safely and successfully. Balloon fenestration was used in 16 procedures, alone or in combination with a limited wire pull component. Adjunct procedures for distal seal included surgeon-modified fenestrated stent graft (3), iliac branch device (3), parallel superior mesenteric artery stent-graft (1), renal artery or superior mesenteric artery stent-graft (4), iliac stent (3), and plug obliteration of FL (5). Reintervention was required in 3 patients due to delayed loss of seal after the initial procedure (3, 8, and 12 months). Two were managed by repeat DLZO and distal extension. The third had distal extension via a surgeon-modified fenestrated stent-graft component. Follow-up imaging was available in 14 patients (16.0 ± 12.5 months, range: 1-33), with stable or regressed sac diameter with complete or near-complete thrombosis of the FL in all patients.

Conclusions: DLZO enabled creation of a distal seal zone in all patients. Residual retrograde filling of the FL is a marker of procedure failure, especially when seal segment length or feasible endoprosthesis oversizing are marginal. Insufficient landing segment can be circumvented with the use of a fenestrated or branched device to accomplish seal in the visceral aorta or iliac bifurcation. Adjunct FL ablation is also a valuable technique to promote FL thrombosis.

Keywords: chronic aortic dissection; endoleak; fenestrated stent-grafts; septal fenestration; thoracic endovascular aortic repair.