Comparison of bridging stent grafts in branched endovascular aortic repair

BACKGROUND

Endovascular treatment of thoracoabdominal aortic aneurysms has become common, with satisfactory results. Nevertheless, long-term durability remains an issue mainly because of target visceral vessel (TVV) instability. Currently, no covered stent has been approved as a bridging stent graft (BSG), demanding continuous research on this topic.

METHODS

This was a multicenter observational retrospective cohort study comparing the midterm results of the Bard Covera Plus and Gore VBX as BSGs during branched endovascular aneurysm repair. The primary outcome was the comparison of the target vessel instability between the two groups. Primary patency, freedom from branch-related type I and III endoleaks and reintervention, and technical and clinical success were considered secondary outcomes. Logistic regression analysis was used to assess the association between selected baseline factors and TVV instability. TVV instability during follow-up was then evaluated using the Kaplan-Meier cumulative function.

RESULTS

Three hundred forty-five TVVs in 106 patients were considered suitable for the analysis. Two hundred twenty vessels were stented with the Covera stent graft (64%) and 125 with VBX (36%). Two hundred ninety-nine TVVs received a single BSG, 45 two BSGs, and only 1 three BSGs. Bare metal stent relining was required in 36% of TVVs, mostly in the Covera group (89 [41%] vs 36 [29%]) (P = .030). The primary technical success rate was 96% (331/345), and the assisted primary technical success rate was 99% (342/345). The TVV instability rate within 30 days was 2% (one Covera and five VBX; P = .015). Three BSG occlusions (one Covera and two VBX) and three type Ic endoleaks (three VBX) were detected. The median follow-up was 13.9 months (range, 5.8-25.5 months). Sixteen TVV instabilities were detected during the follow-up. Twelve BSG occlusions (six Covera and six VBX), three type Ic endoleaks (one Covera and two VBX), and one type IIIc endoleak (VBX). The overall target vessel instability rate was 5% (16/342). TVV instability was associated with the use of Gore VBX in the univariable logistic regression (odds ratio, 3.0; 95% confidence interval, 1.1-8.0; P = .027). Aneurysm rupture and aneurysm diameter were also associated with TVV instability in the univariable analysis (P = .002 and P = .008, respectively). The only factor predisposing to TVV instability in the multivariable logistic regression analysis was the use of Gore VBX as a BSG (odds ratio, 2.9; 95% confidence interval, 1.0-8.0; P = .043). Kaplan-Meier analysis showed a significantly higher risk of TVV instability in the VBX group (P < .001).

CONCLUSIONS

Overall midterm outcomes in this cohort were satisfactory. Patency rates were similar between the two stents. Nevertheless, VBX seems to be associated with worse TVV instability. These results may be correlated with a higher incidence of type Ic endoleaks, which require an extensive learning curve for correct stent selection and deployment.

Structure-reactivity analysis of novel hypervalent iodine reagents in S-vinylation of thiols

The transition-metal free S-vinylation of thiophenols by vinylbenziodoxolones (VBX) constituted an important step forward in hypervalent iodine-mediated vinylations, highlighting the difference to vinyliodonium salts and that the reaction outcome was influenced by the substitution pattern of the benziodoxolone core. In this study, we report several new classes of hypervalent iodine vinylation reagents; vinylbenziodazolones, vinylbenziodoxolonimine and vinyliodoxathiole dioxides. Their synthesis, structural and electronic properties are described and correlated to the S-vinylation outcome, shedding light on some interesting facets of these reagents.

Aryl-, Akynyl-, and Alkenylbenziodoxoles: Synthesis and Synthetic Applications

Hypervalent iodine reagents are in high current demand due to their exceptional reactivity in oxidative transformations, as well as in diverse umpolung functionalization reactions. Cyclic hypervalent iodine compounds, known under the general name of benziodoxoles, possess improved thermal stability and synthetic versatility in comparison with their acyclic analogs. Aryl-, alkenyl-, and alkynylbenziodoxoles have recently received wide synthetic applications as efficient reagents for direct arylation, alkenylation, and alkynylation under mild reaction conditions, including transition metal-free conditions as well as photoredox and transition metal catalysis. Using these reagents, a plethora of valuable, hard-to-reach, and structurally diverse complex products can be synthesized by convenient procedures. The review covers the main aspects of the chemistry of benziodoxole-based aryl-, alkynyl-, and alkenyl- transfer reagents, including preparation and synthetic applications.

Kissing Viabahn VBX stent graft reconstruction of thoracic central veins for management of superior vena cava syndrome

OBJECTIVE

In the present study, we evaluated the technical and clinical outcomes of thoracic central vein reconstruction for superior vena cava (SVC) syndrome using kissing Viabahn VBX stent grafts (W.L. Gore & Associates, Flagstaff, AZ).

METHODS

All adult patients with SVC syndrome who had undergone attempted bilateral brachiocephalic vein-to-SVC reconstruction using kissing VBX stent grafts at an academic hospital between August 2019 and February 2021 were reviewed. The technical results, adverse events, imaging follow-up findings, and clinical outcomes were recorded. Patency over time was assessed using Kaplan-Meier analysis.

RESULTS

A total of 28 patients (16 women and 12 men; mean age, 52.0 years) constituted the study cohort. Of the 28 patients, 17 (60.7%) had had benign and 11 (39.3%) malignant etiologies. The presenting symptoms included neck swelling (n = 17; 60.7%), bilateral upper extremity swelling (n = 15; 53.6%), dyspnea (n = 7; 25%), unilateral upper extremity swelling (n = 4; 14.3%), and dysphagia (n = 1; 3.6%). SVC reconstruction with VBX stent grafts in a kissing configuration was successfully completed in 27 of the 28 patients (96.4%). Four major adverse events were noted in the benign etiology subgroup (23.5%), including intraprocedural hemopericardium (n = 3) and delayed pneumothorax (n = 1). Of the 28 patients, 27 (96.4%) had experienced resolution of their presenting symptoms. The mean clinical follow-up for the living patients was 358.8 ± 77.2 days (range, 78-645 days). The mean imaging follow-up for the living patients was 272.6 ± 91 days (range, 26-594 days). The primary, primary-assisted, and secondary patency rates at 12 months were 71.8%, 88.8%, and 100%, respectively.

CONCLUSIONS

For the management of SVC syndrome, thoracic central vein reconstruction with kissing VBX stent grafts was feasible with a high rate of symptom resolution and acceptable patency. However, this technique should not be recommended for those with benign SVC syndrome owing to the high risk of cardiac tamponade.