Comparison of various methods of vessel ligation: what is the safest method?

Abstract

Recently, various hemostatic devices, such as metal or plastic clips, ultrasonic coagulating shears, and electrothermal bipolar vessel sealer, have been widely applied during an operation. The purpose of this study was to analyze the mechanical, histological, and biochemical differences of vessels sealed with various hemostatic devices. Thirty New Zealand White rabbits were randomly allocated into five groups, and short gastric vessels were ligated with metal clip, plastic clip, Harmonic Ace, LigaSure, or tie ligation. These vessels were harvested 3 days after operation and histologically analyzed at the site of ligation (proximal) and 5 mm from it (distal). Perivascular fibrosis was assessed on a score of mild to severe according to the severity. Inducible and endothelial nitric oxide synthase (iNOS and eNOS) mRNA expressions were measured quantitatively by real-time PCR at the sites of ligation. Abdominal aorta and inferior vena cava also were harvested and divided with each tool, and bursting pressures were measured. Bursting pressures were measured in 164 arteries and 141 veins. LigaSure showed significantly lower bursting pressures in arteries (p < 0.001), and plastic clip showed significantly lower bursting pressures in veins (p < 0.001). There was a negative relationship between outer diameters and bursting pressures in both the arteries (rho = -0.505, p < 0.001) and the veins (rho = -0.106, p = 0.24). The degree of perivascular fibrosis was not statistically different in either the proximal (p = 0.447) or distal (p = 0.381) sites. The expressions of iNOS and eNOS were significantly lower in the LS group (p < 0.001, and p < 0.001, respectively). There might be no clinical limitations when applying various hemostatic devices to small vessels under physiologic blood pressures. There were no acute histological differences between the hemostatic devices. However, LS showed the lowest iNOS and eNOS expressions, which might be due to thermal injuries of the whole vessel wall.