Tissue Structure as a Primary Factor Influencing Vascular Sealing: Results of an Ex Vivo Study on Porcine Carotid...

Bipolar vessel sealing systems are widely used in surgery, yet their effectiveness varies depending on the histological composition of the target vessel. In particular, the influence of elastin on seal stability is not well understood. Porcine carotid arteries, which show a pronounced proximal-distal elastin gradient, provide an ideal model for systematic analysis. In this study, fresh porcine carotid arteries were divided into three segments based on vessel diameter (<5 mm, 5-7 mm, >7 mm). Histological EvG staining was used to quantify elastin and collagen content. All vessels (n = 8 per group) were sealed using a bipolar marSeal^® 5 plus device, followed by burst pressure testing and peel force measurements. Elastin content increased significantly from peripheral to central segments (9% → 25% → 42%; p < 0.001), while collagen content remained constant (22 ± 2%). In parallel, seal stability decreased markedly: burst pressures dropped from 723 mmHg to 240 mmHg and to 31.5 mmHg (p < 0.001). Peel forces showed the same trend (1.75 ± 0.07 N → 0.65 ± 0.03 N → 0.26 ± 0.11 N; p < 0.001). Wall thickness showed no proportional relationship to seal quality. Interestingly, the sealing performance of bipolar systems seems to be greatly influenced by the histological structure of the vessel wall. A high elastin content-rising from 9% to 42% along the carotid artery-was associated with a reduction in burst pressure and peel strength. These findings highlight the need to consider tissue composition when selecting sealing methods and support the development of adaptive energy delivery technologies.