Thoracic endovascular aortic repair for hyperacute, acute, subacute and chronic type B aortic dissection: Meta-analysis of reconstructed time-to-event data

Acute Aortic Dissection After Transcatheter Aortic Valve Replacement

Acute aortic dissection (AAD) is a rare and potentially fatal complication associated with transcatheter aortic valve replacement (TAVR). Owing to the paucity of existing institutional data, we sought to assess the incidence of postimplant AAD in patients who underwent TAVR at a single institution. All patients who underwent TAVR from 2013 to 2022 were retrospectively reviewed to identify those who possessed clinical or radiologic evidence of AAD after TAVR. Follow-up and survival data were retrieved for all included patients. A total of 4,317 patients underwent TAVR, of whom 9 (0.2%) sustained an AAD. These patients had a mean age of 80 years (range 53 to 92), mean Society of Thoracic Surgeons 30-day mortality risk of 5.7% (2.4% to 16.7%), and mean effective aortic valve area of 0.8 cm2 (0.4 to 1.5 cm2). Preoperative maximum aortic diameter was 3.9 cm (2.6 to 4 cm). Of these 9 patients, 6 (67%) showed evidence of Stanford type A dissection, whereas 3 (33%) were diagnosed with Stanford type B dissection. The most common causes of dissection were posterior annular rupture by the transcatheter valve (THV) (44%) and THV embolization or "pop-out" into the ascending aorta (22%). A total of 6 patients (66.7%), comprising 5 type A (55.6%) and 1 type B (11.1%) aortic dissections, died within 30 days of AAD. The median time to follow-up in those surviving TAVR with intraoperative AAD was 1,042 days (range: 648 to 2,666). Surviving patients were managed through thoracic endovascular aortic repair and medical management. In conclusion, in this highly selected cohort of patients, our experience indicates that AAD after TAVR is a rare but often lethal intraprocedural sequela of THV implantation, especially in cases of type A aortic dissection.

Clinical outcomes and aortic remodeling after Castor single-branched stent-graft implantation for type B aortic dissections involving left subclavian artery

Background

The left subclavian artery (LSA) can be intentionally covered by a stent graft to acquire adequate landing zones for a proximal entry tear near the LSA during thoracic endovascular aortic repair (TEVAR). The Castor single-branched stent graft is designed to treat type B aortic dissection (TBAD) to retain the LSA during TEVAR. This study investigates clinical outcomes, aortic remodeling, and abdominal aortic perfusion patterns after TEVAR with the novel Castor device.

Methods

From November 2020 to June 2023, 29 patients with TBAD involving the LSA were treated with the Castor single-branched stent graft. In-hospital clinical outcome and aortic computed tomography angiography (CTA) data were analyzed. CTA was performed preoperatively and at follow-up to observe stent morphology; branch patency; endoleak; change in true lumen (TL), false lumen (FL), and transaortic diameters; and abdominal aortic branch perfusion pattern.

Results

The technical success rate was 96.6%. One failure was that the branch section did not completely enter the LSA and the main body migrated distally. No in-hospital mortality, paraplegia, or stroke occurred. During follow-up, one type Ib endoleak, four distal new entry tears, and one recurrent type A dissection arose from a new entry tear at the ascending aorta, no stent migration was observed, and the branch patency rate was 100%. At the thoracic aorta, TL diameters significantly increased, FL diameters markedly decreased, and FL was partially or completely thrombosed in most patients at follow-up. At the abdominal aorta, we observed 33.3% of TL growth and 66.7% of TL stabilization or shrinkage. The initial TL ratio at iliac bifurcation negatively predicted abdominal TL growth after TEVAR with a cutoff of 21.0%. Of the 102 abdominal aortic branches, 94.1% of the branches showed no change in perfusion pattern, 3.9% of the branches had an increased TL perfusion, and 2.0% of the branches had an increased FL contribution.

Conclusion

The Castor unibody single-branched stent graft offers an efficient endovascular treatment for TBAD involving the LSA. TEVAR with the Castor device effectively induced thoracic FL thrombosis and thoracic TL enlargement and resulted in abdominal TL growth when the initial TL ratio at iliac bifurcation is less than 21.0%. Abdominal aortic branch perfusion patterns remain relatively stable after TEVAR with the Castor stent graft.

Predicting adverse events after thoracic endovascular aortic repair for patients with type B aortic dissection

The potential of adverse events (AEs) after thoracic endovascular aortic repair (TEVAR) in patients with type B aortic dissection (TBAD) has been reported. To avoid the occurrence of AEs, it is important to recognize high-risk population for prevention in advance. The data of 261 patients with TBAD who received TEVAR between June 2017 and June 2021 at our medical center were retrospectively reviewed. After the implementation of exclusion criteria, 172 patients were finally included, and after 2.8 years (range from 1 day to 5.8 years) of follow up, they were divided into AEs (n = 41) and non-AEs (n = 131) groups. We identified the predictors of AEs, and a prediction model was constructed to calculate the specific risk of postoperative AEs at 1, 2, and 3 years, and to stratify patients into high-risk (n = 78) and low-risk (n = 94) group. The prediction model included seven predictors: Age > 75 years, Lower extremity malperfusion (LEM), NT-proBNP > 330 pg/ml, None distal tear, the ratio between the diameter of the ascending aorta and descending aorta (A/D ratio) > 1.2, the ratio of the area of the false lumen to the total aorta (FL ratio) > 64%, and acute TEVAR, which exhibited excellent predictive accuracy performance and discriminatory ability with C statistic of 82.3% (95% CI 77.3-89.2%). The prediction model was contributed to identify high-risk patients of postoperative AEs, which may serve to achievement of personalized treatment and follow-up plans for patients.