Ex vivo endothelial denudation of porcine aortic valves.

BACKGROUND

Aortic valve stenosis (AS) is a progressive and life-threatening condition characterized by narrowing of the aortic valve, leading to impaired outflow from the left ventricle and increased cardiovascular risk. With rising disease prevalence in aging populations and the absence of effective pharmacological treatments, reliable animal models are crucial for studying disease mechanisms and evaluating new therapeutic approaches. The response-to-tissue-injury is considered a key driver of valvular degeneration, yet current models remain limited. This study aimed to assess whether cryoballoon (CB) and radiofrequency (RF) ablation can induce controlled injury in ex vivo porcine aortic valves as a first step toward developing a large-animal model of AS.

METHODS AND

RESULTS

Twelve porcine hearts (3-4 months, 35-50 kg, male, German noble pig × Pietran hybrids) were harvested immediately post-euthanasia, preserved in cardioplegic solution, and processed within 1 h. Ex vivo aortic valves underwent CB ablation or RF ablation using irrigated catheters. Valves were sectioned and examined histologically (HE and vWF staining). Both CB and RF ablation produced consistent and significant mechanical injury at the microscopic level. Despite this, macroscopic valve appearance and overall tissue architecture remained preserved. vWF staining confirmed marked endothelial disruption, particularly pronounced in RF-treated samples.

CONCLUSIONS

CB and RF ablation reliably induce endothelial injury in ex vivo porcine aortic valves without causing gross structural damage. As endothelial disruption represents an essential early trigger for valvular degeneration, these findings provide an important foundation for the development of an in vivo porcine AS model, enabling improved understanding of disease mechanisms and evaluation of future therapeutic strategies.