Category: General

Histol Histopathol. 2024 Oct 31:18842. doi: 10.14670/HH-18-842. Online ahead of print.

ABSTRACT

OBJECTIVES: To analyze and compare, in an animal model, the treatment of thoracoabdominal aneurysms with multilayer stents and its hemodynamic effects through the biomechanical and histological analysis of the aortic wall in contact with the stent.

METHODS: Large White pigs were randomized into two groups: Stent (n=6) and Control (n=5, non-stent). All animals were subjected to the creation of a suprarenal aneurysm with a bovine pericardial patch. In the Stent group, a multilayer stent was implanted immediately after aneurysm formation. After four weeks, all animals were subjected to angiographic assessment and intravascular ultrasound, and the stent was explanted before euthanasia for histological and biomechanical analyses.

RESULTS: At histological analysis, the groups did not differ significantly in maximum thickness of the intima (p=0.526), media (p=0.129), or adventitia (p=0.662). Thrombus formation was observed in 100% of the animals on the intima and media layers of the stented aorta vs. none in the Control group (p=0.048). At biomechanical analysis, no statistical differences were observed in aortic wall elasticity (p=0.158), strength (p=0.360), or thickness (p=0.323).

CONCLUSION: We identified thrombosis of the aneurysmal sac through the presence of thrombi on the intima of the aorta in 100% of the animals in the Stent group; as for the biomechanical analysis, this study showed no statistical differences in vessel wall thickness, strength, and elasticity between groups.

PMID:39552283 | DOI:10.14670/HH-18-842

Eur J Cardiothorac Surg. 2024 Dec 26;67(1):ezae414. doi: 10.1093/ejcts/ezae414.

ABSTRACT

OBJECTIVES: Safety, efficacy and durability are important considerations when selecting a bioprosthesis for aortic valve replacement (AVR). This study assessed 7-year clinical outcomes and haemodynamic performance of the Avalus bioprosthesis.

METHODS: Patients indicated for surgical AVR were enrolled in this prospective, nonrandomized trial, conducted across 39 sites globally. The primary end-point of this analysis was freedom from surgical explant or percutaneous valve-in-valve reintervention due to structural valve deterioration (SVD) at 7 years of follow-up, determined using Kaplan-Meier (KM) analysis. We also evaluated a composite end-point of SVD and/or severe haemodynamic dysfunction requiring reintervention. Survival, valve-related safety events and haemodynamic performance were assessed. Deaths and safety events were adjudicated by an independent clinical events committee.

RESULTS: A total of 1132 patients underwent surgical AVR. Mean age was 70 years; 854 patients (75%) were men. The mean STS risk of mortality was 2.0 ± 1.4%, and 659 patients (58%) had a New York Heart Association classification of I/II. One or more concomitant procedures were performed in 577 patients (51%). At 7 years, the Kaplan-Meier rate of freedom from SVD/severe haemodynamic dysfunction requiring reintervention was 1.2% (0.5-2.5%) with no cases adjudicated as SVD. The survival rate was 82.6% (79.5-85.0%). The KM event rate was 5.7% (4.3-7.7%) for reintervention, 6.3% (4.9-8.3%) for endocarditis and 0.4% (0.1-1.1%) for valve thrombosis. Mean aortic gradient, dimensionless velocity index and effective orifice area were 13.8 ± 5.9 mmHg, 0.42 ± 0.09 and 1.99 ± 0.53 cm2, respectively.

CONCLUSIONS: This analysis demonstrated excellent durability of the Avalus valve with good clinical outcomes and stable haemodynamic performance through 7 years of follow-up.

PMID:39565905 | PMC:PMC11742136 | DOI:10.1093/ejcts/ezae414