Impact and risk factors associated with false lumen thrombus status within stent segments of type B aortic dissection after endovascular repair

BACKGROUND: The aim of this study was to elucidate the impact and risk factors associated with a partial thrombosis within a stent-covered false lumen (SCFL) for Stanford type B aortic dissection (STBAD) after surgery.METHODS: The study included 129 patients with STBAD undergoing endovascular repair between January 2014 and December 2017. They were divided into two groups (complete thrombosis, N.=93; partial thrombosis, N.=36) based on SCFL thrombus status.RESULTS: SCFL partial thrombosis had a higher aortic mortality (8.3% vs. 1.1%, P=0.033) and reintervention (16.7% vs. 4.3%, P=0.028) than complete thrombosis. Five-year survival was significantly lower in the partial thrombosis when compared to the complete thrombosis (91.1% vs. 98.9%, P=0.035). SSFL partial thrombosis was linked to a higher incidences of type Ia endoleak (25.0% vs. 3.2%, P=0.000), type II endoleak (13.9% vs. 0.0%, P=0.001), stent-induced new entry (16.7% vs. 3.2%, P=0.007), stent-distal false lumen (SDFL) patency (44.5% vs. 21.5%, P=0.009) and postoperative descending aortic aneurysmal dissection (post-dAAD) (33.3% vs. 9.7%, P=0.001) than complete thrombosis. Type II endoleak (HR: 5.886, 95% CI: 1.963-17.646, P=0.002) and SDFL patency (HR: 2.234, 95% CI: 1.113-4.486, P=0.024) were two predictors of SCFL partial thrombosis. Moreover, the post-dAAD was an independent predictor of mortality (HR: 15.52, 95% CI: 1.614-149.233, P=0.018).CONCLUSIONS: SCFL partial thrombosis was associated with an increase in adverse aortic events. Type II endoleak and SDFL patency were two predictors of SCFL partial thrombosis.