Loose fascial closure and fascial defects: effects on laparotomy healing in rats

Abstract

Every suture technique in surgery aims at connecting tissue structures until stable scar formation has developed. Although the negative effects of high suture tension on the mechanical properties of the developing scar are well known, the applied suture tension has not been standardized and depends on the surgeon's experience. In this study the effects of low suture tension on laparotomy closure were studied in rats and an incisional hernia model was developed. Median laparotomies were closed by running suture using Foley-catheters with a diameter of 2.4, 4.8 and 7.2 mm as distance holders. In another group, an abdominal wall defect of 2 cm diameter was created and covered internally by larger omentum. After 28 days laparotomies closed using a distance holder with diameter of 2.4 and 4.8 mm had healed without developing fascial dehiscence or incisional hernia. With 7.2 mm catheters all animals developed a ruptured abdomen. All animals with abdominal wall defects developed incisional hernias with stable hernial sacs without significant inflammatory reaction. Laparotomy closure intentionally performed with a surplus of suture material of up to 21% per stitch in a 4 cm incision does not result in a disturbance of wound healing or hernia formation. Creating an abdominal wall defect with an internal covering of great omentum in rats reliably results in incisional hernia formation closely resembling that found in humans. These results underline the necessity to further determine values for tissue-specific suture tension experimentally.