How should we manage type B aortic dissections?

Mid- and long-term results of open repair for chronic type B aortic dissection in endovascular era

Medical management is the standard treatment of chronic type B aortic dissection (CTBAD). However, the roles of open surgical repair (OSR) and thoracic endovascular repair (TEVAR) in patients with CTBAD remain controversial. Thus, this study aimed to assess and compare the mid- and long-term clinical outcomes of OSR via left thoracotomy with that of TEVAR for CTBAD. The data of 85 consecutive patients who underwent surgery for CTBAD from April 2007 to May 2021 were retrospectively reviewed. The patients were divided into two groups: Group G, which included patients who underwent OSR, and Group E, which included patients who underwent TEVAR. Groups G and E comprised 33 and 52 patients, respectively. Preoperative and postoperative computed tomography (CT) studies were retrospectively analyzed for the maximum diameter. The mean duration of the follow-up period was 5.8 years. Operative mortality did not occur. There was no difference in complications, such as stroke (G: 2 vs. E: 0, p = 0.30), paraplegia (G: 1 vs. E: 1, p = 0.66), and respiratory failure (G: 2, vs. E: 0, p = 0.30). The difference in preoperative factors was observed, including the intervals between onset and operation (G; 4.9 years vs. E; 1.9 years, p < 0.01), maximum diameter in preoperative CT (G; 59.0 mm vs. E; 50.5 mm, p < 0.001), and maximum false lumen diameter (G; 35.5 mm vs. E; 29.0 mm, p < 0.01). There was no significant difference in the mid- and long-term survival rates (p = 0.49), aorta-related deaths (p = 0.33), and thoracic re-intervention rates (p = 0.34). Postoperative adverse events occurred in Group E: four cases of retrospective type A aortic dissection, two cases of aorto-bronchial fistula, and one case of aorto-esophagus fistula. Aorta-related death and re-intervention rates crossed over in both groups after seven years postoperatively. Although endovascular repair of CTBAD is less invasive, the rate of freedom from re-intervention was unsatisfactory. Some fatal complications were observed in the endovascular group, and the mid- and long-term outcomes were reversed compared with those in the OSR group. Although OSR is an invasive procedure, it could be performed safely without perioperative complications. OSR has more feasible mid- and long-term outcomes.

Potential biomarkers of aortic dissection based on expression network analysis

Background

Aortic dissection (AD) is a rare disease with severe morbidity and high mortality. Presently, the pathogenesis of aortic dissection is still not completely clear, and studying its pathogenesis will have important clinical significance.

Methods

We downloaded 28 samples from the Gene Expression Omnibus (GEO) database (Accession numbers: GSE147026 and GSE190635), including 14 aortic dissection samples and 14 healthy controls (HC) samples. The Limma package was used to screen differentially expressed genes. The StarBasev2.0 tool was used to predict the upstream molecular circRNA of the selected miRNAs, and Cytoscape software was used to process the obtained data. STRING database was used to analyze the interacting protein pairs of differentially expressed genes under medium filtration conditions. The R package "org.hs.eg.db" was used for functional enrichment analysis.

Results

Two hundred genes associated with aortic dissection were screened. Functional enrichment analysis was performed based on these 200 genes. At the same time, 2720 paired miRNAs were predicted based on these 200 genes, among which hsa-miR-650, hsa-miR-625-5p, hsa-miR-491-5p and hsa-miR-760 paired mRNAs were the most. Based on these four miRNAs, 7106 pairs of circRNAs were predicted to be paired with them. The genes most related to these four miRNAs were screened from 200 differentially expressed genes (CDH2, AKT1, WNT5A, ADRB2, GNAI1, GNAI2, HGF, MCAM, DKK2, ISL1).

Conclusions

The study demonstrates that miRNA-associated circRNA-mRNA networks are altered in AD, implying that miRNA may play a crucial role in regulating the onset and progression of AD. It may become a potential biomarker for the diagnosis and treatment of AD.

High intimal flap mobility assessed by intravascular ultrasound is associated with better short-term results after TEVAR in chronic aortic dissection

Thoracic endovascular aortic repair (TEVAR) in chronic aortic dissection remains controversial. We analysed whether a high intimal flap mobility (IFM) of the dissection membrane has an impact on aortic remodelling after TEVAR in chronic Type B aortic dissection. Patients undergoing TEVAR with intravascular ultrasound (IVUS) were analysed and IFM was calculated. High IFM was defined as maximum flap amplitude >3 mm. For determining aortic remodelling, the degree of true lumen (TL) expansion was analysed in the last available follow-up CT. Fifty-two patients (63.6 ± 15.4 years) with a mean follow-up of 26.6 ± 20.7 months were analysed. The mobile flap group (n = 29) showed higher absolute TL expansion at the distal stent-graft (5.9 ± 3.1 vs. 3.3 ± 5.4 mm; p = 0.036) and a higher increase in TL diameter (18 ± 10 vs. 9 ± 15%; p = 0.017) compared to the non-mobile group (n = 23). Basic TEVAR-related outcome characteristics were comparable, but the mobile intimal flap group showed a lower re-intervention rate (3 vs. 8pts.; p = 0.032) in chronic dissections. High IFM in chronic Type B aortic dissection is linked to improved aortic remodelling and is associated with a lower re-intervention rate over time. IVUS assessment of IFM in chronic Type B aortic dissection might be helpful in identifying patients with better remodelling after TEVAR.

Indications for Thoracic EndoVascular Aortic Repair (TEVAR): A Brief Review

The utility of Thoracic EndoVascular Aortic Repair (TEVAR) continues to progress at a very rapid rate. Initially implemented for the treatment of thoracic aortic aneurysms, TEVAR has evolved to treat a variety of aortic pathologies and reduce overall morbidity and mortality rates compared with traditional open surgical repair. Given the rapidly evolving nature of endovascular thoracic intervention, we hereby briefly review the current literature on the evolving applications of TEVAR. TEVAR continues to rapidly evolve and is being applied to a growing number of aortic pathologies. Given the perioperative, short- and mid-term morbidity and mortality rates, TEVAR is quickly surpassing traditional open surgical intervention as the ideal procedure for patients undergoing intervention of the descending thoracic aorta and applicability to ascending and arch pathologies is being explored. However, as more data becomes available TEVAR may be associated with higher rates of reoperative requirements. Data remains limited on the long-term efficacy of the intervention and should continue to be investigated.