Proximal stent graft combined with distal bare stent vs. conventional thoracic endovascular aortic repair in the treatment of complicated Stanford type B aortic dissection: a systematic review and meta-analysis.

Background: The combination of a proximal stent graft (PSG) and a distal bare stent (DBS) has a number of advantages over standard thoracic endovascular aortic repair (TEVAR) in the treatment of complicated Stanford type B aortic dissection (TBAD). However, direct comparisons between these two treatment approaches remain limited. This meta-analysis aimed to compare the efficacy of these techniques in the treatment of complicated Stanford TBAD. Methods: The Cochrane Library, Embase, PubMed, and Web of Science databases were searched using the following key terms: "provisional extension to induce complete attachment technique", "petticoat", "restrictive stent", "protective stent", "bare stent", and "aortic dissection". All articles relevant to the topic were included in the meta-analysis. The following variables were compared between the two approaches: aortic-related mortality (ARM), false lumen (FL) thrombosis, and complications, such as endoleak, aortic rupture, paraplegia or paraparesis, stroke, renal failure, retrograde dissection, conversion to open repair, reintervention, and stent graft-induced new entry (SINE). Results: A total of 15 studies comprising 1,462 patients were included in the meta-analysis. Of the patients, 635 received a bare stent (the BS group) and 827 received a standard TEVAR (the non-BS group). There were no statistically significant differences between the two groups in terms of the 30-day ARM rate [risk ratio (RR): 0.59; 95% confidence interval (CI): 0.26-1.34; P=0.21], endoleak (RR: 0.87; 95% CI: 0.49-1.53; P=0.62), aortic rupture (RR: 0.65; 95% CI: 0.22-1.94; P=0.44), paraplegia or paraparesis (RR: 0.54; 95% CI: 0.22-1.32; P=0.17), stroke (RR: 0.91; 95% CI: 0.38-2.15; P=0.83), renal failure (RR: 2.35; 95% CI: 0.75-7.43; P=0.14), and retrograde dissection (RR: 1.06; 95% CI: 0.33-3.40; P=0.92). However, the >30-day ARM rate (RR: 0.58; 95% CI: 0.34-0.98; P=0.048), overall ARM rate (RR: 0.58; 95% CI: 0.38-0.88; P=0.01), conversion to open repair (RR: 0.28; 95% CI: 0.08-0.99; P=0.052), reintervention (RR: 0.40; 95% CI: 0.26-0.61; P<0.001), and SINE (RR: 0.14; 95% CI: 0.06-0.32; P<0.001) were significantly reduced in the BS group compared to the non-BS group. Additionally, while there was no significant difference between the two groups in terms of complete FL thrombosis at the thoracic level (RR: 1.20; 95% CI: 0.95-1.52; P=0.13), the two groups differed significantly in terms of complete FL thrombosis at the abdominal level (RR: 2.49; 95% CI: 1.37-4.53; P=0.003). Conclusions: Compared with standard TEVAR, combining a PSG with a DBS moderately reduces postoperative complications, and enhances remodeling of the aorta, and thus has advantages in the treatment of complicated Stanford TBAD.