Long-Term Aortic Remodeling After Thoracic Endovascular Aortic Repair of Acute, Subacute, and Chronic Type B Dissections

Mid-term efficacy of castor stent and in situ fenestration stent in the treatment of type B aortic dissection involving the left subclavian artery: A retrospective single-center study

To evaluate the midterm efficacy of the Castor stent (CS) versus in situ fenestration (ISF) for reconstructing the left subclavian artery (LSA) in patients with type B aortic dissection (TBAD). Between July 2017 and July 2022, a total of 247 patients with TBAD were enrolled. One hundred thirty-seven patients were treated using CSs (group A), while the remaining 110 patients received ISFs (group B). Data of the two groups were retrospectively analyzed. The success rates of surgery were 99.3% and 95.5% in groups A and B (p = .053), There were no deaths during hospitalization. During surgery, group B showed a longer surgical duration [68.0 (66.0, 77.0) vs. 62.0 (59.0, 66.0) min, p < .001] and intraoperative fluoroscopy time [18.0 (16.0, 20.0) vs. 16.0 (14.0, 18.0) min, p < .001] than group A. The follow-up duration was similar for both groups (44.0 vs. 43.0 months, p = .877), and no patient died. Stent-related complications were significantly lower in group A than in group B (1.5% vs. 8.4%, p = .009). Group A had fewer instances entry flow (0.7% vs. 4.7%, p = .048) and stent stenosis (0.7% vs. 2.8%, p = .206) than group B. All reintervention cases (4.7%) were from group B (p = .011). The rate of false aortic lumen thrombosis was significantly higher in group A than in group B (84.6% vs. 72.9%, p = .024). Both CSs and ISFs are evidently safe, feasible, and effective in achieving positive early outcomes in patients undergoing treatment for TBAD. Notably, at midterm follow-up, CSs appeared to be superior to ISF in terms of reducing stent-related complications and minimizing the need for reintervention.

The Influence of Minor Aortic Branches in Patient-Specific Flow Simulations of Type-B Aortic Dissection

Type-B aortic dissection (TBAD) is a disease in which a tear develops in the intimal layer of the descending aorta forming a true lumen and false lumen (FL). Because disease outcomes are thought to be influenced by haemodynamic quantities such as pressure and wall shear stress (WSS), their analysis via numerical simulations may provide valuable clinical insights. Major aortic branches are routinely included in simulations but minor branches are virtually always neglected, despite being implicated in TBAD progression and the development of complications. As minor branches are estimated to carry about 7-21% of cardiac output, neglecting them may affect simulation accuracy. We present the first simulation of TBAD with all pairs of intercostal, subcostal and lumbar arteries, using 4D-flow MRI (4DMR) to inform patient-specific boundary conditions. Compared to an equivalent case without minor branches, their inclusion improved agreement with 4DMR velocities, reduced time-averaged WSS (TAWSS) and transmural pressure and elevated oscillatory shear in regions where FL dilatation and calcification were observed in vivo. Minor branch inclusion resulted in differences of 60-75% in these metrics of potential clinical relevance, indicating a need to account for minor branch flow loss if simulation accuracy is sought.

Single-branched stent-graft with on-table fenestration for endovascular repair of primary retrograde type A aortic dissection: A multicenter retrospective study

Objective

This study aims to evaluate the feasibility, efficacy, and safety of a single-branched stent-graft with on-table fenestration for primary retrograde type A aortic dissection (RTAD) during thoracic endovascular aortic repair (TEVAR).

Materials and methods

From January 2019 to December 2021, 36 patients with primary RTAD from five tertiary hospitals received medical management in the acute phase. They underwent TEVAR with a proximal zone 1 landing for aortic arch reconstruction in the subacute phase, using a fenestration technique on a single-branched stent-graft. Nearly 2 weeks after admission, computed tomography angiography (CTA) was re-examined to evaluate the thrombosis status of retrograde false lumen (FL). The primary outcomes were technical success, patency of the target branch arteries, and absence of type Ia endoleaks. The second outcomes were stent-graft-related complications and all-cause mortality.

Results

The mean age was 56.2 ± 11.3 years, and 29 (80.6%) were male. After a median interval of 18.0 [interquartile range (IQR), 17.0–20.3] days of medical treatment, the partial and complete thrombosis of proximal FL rates increased to 52.8% and 47.2%, respectively. One patient (2.8%) experienced postoperative type Ia endoleaks, and was successfully re-treated using coli and Onyx glue. The median hospital stay was 20.5 (IQR, 18.0–23.0) days. The overall technical success rate was 100%. The median follow-up time was 31.5 (IQR, 29.8–34.0) months. There was one death (2.8%) due to gastrointestinal bleeding. Distal aortic segmental enlargement (DASE) occurred in two (5.6%) patients. No major complications or recurrent dissections in the proximal landing zone were recorded during follow up.

Conclusion

The retrograde FL in primary RTAD could realize partial or complete thrombosis after medical management in the acute phase, and it might be regarded as a valid proximal landing zone for endovascular repair. The single-branched stent graft with on-table fenestration performed in the subacute phase may be feasible strategy in selective primary RTAD patients.