Effect of electrocautery vs. scalpel on fascial mechanical properties after midline laparotomy incision in rats

Background: The method of midline laparotomy incision and closure remains a complex surgical problem. Objective: To compare the mechanical properties at the interface of midline laparotomy incision made by scalpel versus electrocutting current in rats. Methods: A sharp midline laparotomy incision was made in 60 Wistar female rats using a scalpel or electrocautery to open the fascia. The fascial and skin wounds were closed separately with a continuous nylon. Fascial specimens were analyzed for mechanical properties at the midline incision using a loading machine. The load-extension curve was recorded during tensile loading at a steady extension rate of 15 mm/min. Results: There was no statistically significant difference between the two groups in either wound-bursting force (P_PEAK) or the strain energy spent until the point of measured P_PEAK. Each load-extension curve showed a characteristic pattern in all rats. Tissue stiffness was greater in the scalpel group than in the electrocautery group (P=0.02). Correlations were found between tissue stiffness and strain energy, between tissue stiffness and bursting force, and between bursting force and strain energy. Conclusions: While tissue stiffness was greater when a scalpel was used compared to electrocutting to incise the midline abdominal fascia in rats, there was no difference in the bursting force required to disrupt the wound.