Risk factors on the treatment of cecum injuries with primary suture in rats

Purpose: Analyze the results of primary suture in the treatment of cecum traumatic injuries in rats, after the exposure to increasing time intervals between the trauma and the surgery and with different peritonitis degrees. Methods: In a randomized double-blinded study, 96 Wistar male rats, weight ranging between 200 and 250 grams, underwent laparotomy, in which a 5-milimiter-diameter-injury in the contramesenteric edge of the cecum was performed. In 12 animals of the control-group a prompt primary suture was executed, with total and separated stitches, with 7.0 polypropylene thread. In the other groups, with 12 animals each, a laparotomy for repair of the injury was executed after intervals of 30 minutes, 1, 2, 4, 6, 9 and 12 hours. At the time of injury repair, one of its edges was ressected and sent for anatomopathological examination. A daily control after the surgery was done, observing the presence of complications, specially dehiscence of the suture, and the euthanasia of the animals were done in the 1st, 4th, 7th and 14th day after the surgery. Necropsy was executed in all animals, observing the macroscopic and microscopic findings in the area of suture. Results: There was no association between the delay for surgical treatment of the injury and peritonitis degrees. The mortality in the 14 animals with diffuse peritonitis was 100%. Global mortality was 25% (24 animals), and 6 animals (25%) died before treatment. None of the animals treated that evolved to death had complications related to the suture of the injury. These early deaths were due to peritonitis and sepsis. Among the 72 surviving rats, there was dehiscence of the suture in 9 animals (12.5%). This complication was statistically significant greater in animals operated on after the sixth hour following the trauma. The incidence of dehiscence was also greater in the rats presenting more intense fecal contamination. Intensity of the peritonitis at the moment of suture observed in histological examination had no association with the occurrence of complications of the primary suture. Conclusion: The primary suture as a risky procedure to treat rats, after an interval superior to six hours after the trauma or in the period of intense contamination of the cavity by feces.

Abdominal injuries; Colon; Wounds and Injuries; Trauma; Peritonitis; Animal Experimentation

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