Endovascular repair of type B aortic dissection with the restrictive bare stent technique: morphologic changes, technique details, and outcomes

PURPOSE: The aim of this study was to present our experience and assess the morphologic changes of the descending aorta after the restrictive bare stent (RBS) technique in the treatment of type B aortic dissection (TBAD). PATIENTS AND METHODS: A retrospective study was conducted of 22 consecutive patients with TBAD who underwent RBS treatment between February 2012 and June 2016. Indications for the RBS procedure included radiological evidence of true lumen (TL) compression or collapse and/or tortuosity index (TI) of the descending aorta >1.4. Technique success, descending aorta morphology, and clinical outcomes were evaluated. RESULTS: The technical success rate was 100%. Patients treated with the RBS technique were often accompanied by TL collapse (45.5%) or TI >1.4 (59.1%). One-month postoperative computed tomography angiography showed that the taper ratio, oversizing ratio of the stent graft, and TI values were significantly decreased compared with preoperative computed tomography angiography values (P<0.05). The 30-day mortality rate was 0%. In total 95.2% had a thrombosed false lumen in the segment of aortic coverage, and TL diameters were increased in 40.3%±11% (mean ± SD) and 37.5%±17.9% of patients in the thoracic and abdominal segments, respectively. During the follow-up from 16 to 64 months (33±19 months), no distal stent graft-induced new entry, endoleak, and paraplegia were observed. One patient died from rupture of a chronic TBAD with aneurysm degeneration. CONCLUSION: Mid-term outcomes showed RBS to be a flexible and feasible approach to repair TBAD. RBS corrects the descending aorta morphology and promotes TL expansion in most patients, but the rupture of chronic TBAD with aneurysm degeneration was not prevented in all patients.