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

Prognosis and Remodeling after Endovascular Repair for Acute, Subacute, and Chronic Type B Aortic Dissection

PURPOSE

Thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (TBAD) is already well introduced, but the best time point to perform TEVAR has not been defined. This study was to report mid- to long-term outcomes and aortic remodeling of TEVAR in patients with TBAD.

MATERIALS AND METHODS

In total, 318 TBAD patients from June 2001 to May 2016 were retrospectively reviewed. Patients were divided into 3 groups depending on interval between dissection onset to TEVAR: acute (0-7 days), subacute (8-30 days), and chronic (>30 days). Clinical and morphological data were collected and analyzed.

RESULTS

The follow-up aorta-related mortality rates in the 3 groups were 17.6%, 2.6%, 4.2%, and the proximal stent-induced new entry rates were 11.8%, 1.6%, 2.8%, respectively. Aortic remodeling was satisfied in both the acute and subacute group, but the false lumen diameter did not decrease (p>0.05) in the chronic group. Compared with the VIRTUE classification (acute, 0-14 days; subacute, 15-92 days; chronic, >92 days), mid- to long-term outcomes of patients within the first overlapped interval between the 2 classifications (8-14 days) were similar to that of subacute patients (15-30 days), while aortic remodeling of patients in the second overlapped interval (31-92 days) was similar to that of chronic patients (>92 days).

CONCLUSIONS

This study suggests that TEVAR for subacute TBAD is associated with a low long-term rate of aorta-related death. Aortic remodeling of chronic dissections is not satisfactory. Additional results suggest that the subacute phase (8-30 days) may be the optimal time to perform TEVAR for uncomplicated TBAD.

MANAGEMENT OF LEFT SUBCLAVIAN ARTERY IN TYPE-B AORTIC DISSECTION TREATED WITH THORACIC ENDOVASCULAR AORTA REPAIR

OBJECTIVE

Thoracic endovascular aortic repair (TEVAR) has been the favored approach for the treatment of type B aortic dissection (TBAD). To obtain an adequate proximal landing zone, coverage of the left subclavian artery (LSA) will often be necessary. The occurrence of possible neurologic complications has continued to be debated. We investigated the management of the LSA in patients with TBAD undergoing endovascular repair.

METHODS

We searched the PubMed and MEDLINE databases to October 2020 for studies of TEVAR for TBAD. Data on the study design, demographics, endograft details, LSA coverage and revascularization, mortality, complications, and follow-up were extracted and analyzed. The effects of LSA coverage and revascularization on neurologic complications and outcomes were investigated.

RESULTS

A total of 26 reports (24 retrospective and 2 prospective) were deemed eligible for our study. A total of 1483 patients (mean age, 56.9 ± 6.2 years) had undergone TEVAR for acute (n = 932; 62.9%), subacute (n = 36; 2.4%), or chronic (n = 515; 34.7%) TBAD, with a success rate of 97.8% and hospital mortality of 4.9%. The LSA origin had been covered for 707 patients (47.7%), and 326 had undergone LSA revascularization (surgical, n = 96; endovascular, n = 170; unspecified or not reported, n = 60). LSA revascularization was concomitant for 68.1% of cases, after TEVAR for 1.8%, and not reported for 30.1%. Of 1146 patients, 10 (0.9%) had experienced left arm claudication, and the overall stroke rate was 3.3% (2.7% for the LSA group and 1% for the uncovered LSA group; P = .0815). Of the patients with stroke and a covered LSA, 1% (2 of 203) had undergone LSA revascularization and 4.8% (5 of 105) had not (P = .0478). Twenty-six patients (1.9%) had developed paraplegia: 0.7% (3 of 433) with a covered LSA, 1.4% (7 of 491) with an uncovered LSA (P = .3508), and not reported for 16 patients. Endoleak was present in 138 patients (13.4%) at a mean follow-up of 32.1 ± 25.6 months.

CONCLUSIONS

Our review has shown that LSA coverage during endovascular repair for complicated TBAD will does not significantly increase the risk of neurologic complications; however, revascularization of the LSA should be always recommended.

A meta-analysis of combined proximal stent grafting with or without adjunctive distal bare stent for the management of aortic dissection

BACKGROUND

The efficacy and safety of placement of a proximal covered stent graft combined with a distal bare stent are controversial because of the lack of evidence. This systematic review and meta-analysis compared the outcomes of combined proximal covered stent grafting with distal bare stenting (BS group) and proximal covered stent grafting without distal bare stenting (non-BS group).

METHODS

The MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases and key references were searched up to January 26, 2019. Predefined outcomes of interest were mortality, morbidity, and postoperative assessment of aortic remodeling. We pooled risk ratios (RRs) of the outcomes of interest using fixed effects model or random effects model.

RESULTS

Overall, eight observational studies involving 914 patients were included. There were no significant differences in overall aorta-related mortality (RR, 0.54; confidence interval [CI], 0.24-1.24; P = .15), complete thoracic false lumen (FL) thrombosis rate (RR, 1.23; CI, 0.83-1.81; P = .30), or complete abdominal FL thrombosis rate (RR, 1.96; CI, 0.68-5.69; P = .21) between the BS group and the non-BS group. The BS group had a lower rate of partial thoracic FL thrombosis (RR, 0.40; CI, 0.25-0.65; P = .0002), a lower stent graft-induced new entry rate (RR, 0.08; CI, 0.02-0.41; P = .003), and a lower reintervention rate (RR, 0.42; CI, 0.26-0.69; P = .0005).

CONCLUSIONS

Combined proximal covered stent grafting with distal adjunctive bare stenting had the potential to reduce the partial thoracic FL thrombosis rate and the rates of stent graft-induced new entry and reintervention but was not associated with lower aorta-related mortality or the complete FL thrombosis rate. Further research with a stricter methodology is needed.

Surgical Outcomes And Postoperative Descending Aorta Morphologic Remodeling After Thoracic Endovascular Aortic Repair For Acute And Chronic Type B Aortic Dissection

Background

This study aims to investigate the descending aortic morphological alterations caused by pathological changes in acute and chronic Type B aortic dissection (TBAD) and morphological remodeling after thoracic endovascular aortic repair (TEVAR).

Patients and methods

From February 2012 to January 2016, 86 TBAD patients undergoing TEVAR were divided into an acute group (n=63) and a chronic group (n=23). The areas of the true, false and maximal lumen and descending aorta morphological parameters, including the taper ratio (TR), oversizing ratio (OR), mismatch ratio (MR), radius of curvature (RoC) and tortuosity index (TI), were evaluated. Follow-ups were performed postoperatively before discharge, at 1 and 6 months, and yearly thereafter.

Results

Before TEVAR, the TR (0.57 (0.49) vs 0.74 (0.60); P < 0.05), OR (2.75 ± 1.89 vs 3.96 ± 2.27; P < 0.05) and TI (1.22 (1.19) vs 1.41 ± 0.17; P < 0.05) were significantly higher in the chronic group than in the acute group. The TEVAR technical success rate was 100%. No differences were found in 30-day and >30-day mortality between the two groups. Pathology-specific devices, such as tapered stent grafts and distal bare stents, were used more frequently in the chronic group than in the acute group (47.8% vs 23.8%, P = 0.03; 43.5% vs 12.7%, P = 0.002, respectively). The OR and TI changes that occurred after TEVAR were significantly higher in the chronic group than in the acute group (1.80 ± 0.86 vs 2.98 ± 1.85, P = 0.028; 0.00 ± 0.09 vs 0.09 ± 0.10, P < 0.001, respectively).

Conclusion

TEVAR is a safe and effective therapy for acute and chronic TBAD. Compared to acute TBAD, chronic TBAD resulted in an adverse preoperative descending aorta morphology. Pathology-specific devices may be a feasible treatment option for endovascular repair of chronic TBAD. A larger series of cases with longer follow-up are needed to draw definitive conclusions.