Thermal fusion: effects and interactions of temperature, compression, and duration variables

Abstract

Background: The constraints imposed by minimal access surgery have driven the need for enabling technologies for thermal vessel occlusion or "tissue welding." The objective of this study was to determine the values of, and interaction between, tissue temperature, apposition force, and clamp time for optimum tissue welding.

Methods: A dedicated experimental device with heated occluding jaws was used for ex vivo experiments on harvested sheep carotid vessels. The device allowed individual variation of temperature (60, 70, 80, and 90 °C), compression force (20, 40, 60, and 80 N) and clamp time (5, 10, 15 s). Weld strength was measured by burst pressure.

Results: The best seal quality was obtained at a temperature of 90 °C (p = 0.03), a compression force between 60 and 80 N (p = 0.03), and clamp time of 10 s (p = 0.058). The individual effects of temperature, compression force, and clamp time were all significant at p < 0.001. Although all three were considered to have large effects, clamp time had a reduced effect, relative to temperature and compression force.

Conclusions: Temperature, compression force, and clamp time influence the quality of thermal welding, but the interaction between temperature and apposition force appears to be more dominant.