Determination of the gained proximal sealing zone length after debranching of the left subclavian artery in thoracic endovascular aortic repair.

Background: For descending thoracic aortic aneurysms (TAA) in proximity of the aortic arch, debranching of the left subclavian artery (LSA) may be necessary to extend proximal sealing in zone 2. The aim of this study was to determine the added proximal apposition length gained from LSA debranching during thoracic endovascular aortic repair (TEVAR).

Methods: This multicenter retrospective study (2010-2020) included patients who underwent elective TEVAR in zone 2 for a degenerative TAA where the LSA was surgically debranched. The endograft position on the first postoperative computed tomography angiography (CTA) scan was assessed using post-processing software. The analysis included the shortest apposition length (SAL), the tilt of the proximal edge of the endograft, and the distance between the endograft and the left common carotid artery. Clinical endpoints (neurological complications and endoleaks) at 30 days were also reported.

Results: Twenty-two patients were included. The median interval between TEVAR and the first postoperative CTA was 3 days (2-10 days). Median SAL was 9.2 mm (1.3-26.4 mm), of which 8.6 mm (1.3-16.2 mm) was gained proximal of the LSA, including the LSA orifice. In 12 patients (55.5%) the SAL was <10 mm. The median tilt was 18.3° (13.9°-22.2°). Seven endoleaks were reported on the first CTA: 1 type Ia, 2 type Ib, 3 type II, and 1 type III.

Conclusions: Debranching the LSA adds valuable sealing length in zone 2, but the SAL was still relatively short in many patients, putting these patients at risk for a future type Ia endoleak. Accurate assessment of the circumferential apposition on postoperative CTA follow-up in these high-risk patients with short, complex landing zones seems mandatory. Evaluation of apposition in a larger population with longer follow-up is advised.