Pilot study of minimum occlusive force of vascular clamps on arterial vessels in rats

Abstract

Our aims were to determine the accuracy of an improved formula for determining the minimum occlusive force (MOF) of a vascular clamp on rats’ abdominal aortas, compare our findings with the calculated theoretical MOF, and provide reference data for clinical research and development of medical instruments that cause minimal damage. We created a vessel closure model and developed a formula for calculating the theoretical MOF of arterial vessels when they are occluded. This formula utilises the blood pressure in the blood vessel, its diameter, and the width of the vascular clamp. We then measured the actual MOF in 24 rat abdominal aortic segments with different diameters and different blood pressures and compared the theoretical and actual MOFs. Analysis of the experimental data showed a probability of 0.315, which means that, under the condition of normal distribution, the difference between the theoretical and actual MOF is not significant at the α = 0.05 level. Thus, the actual measured MOF tended to be consistent with the theoretical MOF calculated by the formula we developed. The improved formula will provide a reference for clinical research and development of medical instruments that cause minimal injury, thus contributing to the development of microsurgery.

A new way to avoid excessive damage to blood vessels from haemostatic clips

“…A haemostatic clip only causes minimal vascular damage when the clamping force is 30 g. In our previous experiments, we conducted measurements on 48 SD rats to study the theoretical minimum clamping force. The results showed that the average minimum clamping force of the rat abdominal aorta was approximately 11.78 g [19] . Therefore, in clinical practice, it is crucial to carefully select the appropriate clamping force, as a lower force would result in less damage to the blood vessel when the MOF is achieved and blood ow is safely blocked.…”

“…According to the principle of the MOF, our research group has proposed a calculation formula for the minimum clamping force based on animal experiments, as follows: MOF = 2×(1/2 × π × D×W×BP). The computer-generated mathematical prediction of the MOF involves three factors: vessel diameter, blood pressure, and contact area of the haemostatic clip blade [19] . Therefore, the haemostatic clip is considered safest when it exerts the MOF.…”