An animal model for assessment of heat distribution and neural damage around the endo shears coagulation device-applications for laparoscopic nerve-sparing surgery.

Abstract Background and Purpose: Current urologic laparoscopic procedures include preservation of locoregional nerve fibers. The use of electrical coagulation is limited because of tissue conductance of current and heat production. While ultrasonic coagulation does not use electricity, heat is still produced. We designed an animal model to characterize the heat spread around ultrasonic devices and assess whether it is neurodestructive. Materials and Methods: 10 rats were anesthetized; their skin was reflected, exposing the muscles. An ultrasonic probe was introduced into the tissue, and coagulation was performed for 10 seconds. Tissue temperature was measured using four thermocouples, at distances of 4, 8, 12, and 16 mm from the probes and in a circumferential manner. Thermal mapping of the probes was performed with an infrared camera. Further, four rats were anesthetized; the skin above their inner thighs was reflected bilaterally exposing the “nervus ischiadicus.” Coagulation was performed in varying di...