Small Animal Surgical Emergencies. Группа авторов

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Small Animal Surgical Emergencies - Группа авторов


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are relatively fixed in position due to their attachments to the mesoduodenum and mesocolon. The descending colon is the longest and most mobile segment of the large intestine [2].

      Colonic torsion has been infrequently described in dogs. The majority of patients are large breeds and young to middle aged [1]. The most common clinical signs associated with the disease include vomiting, depression, inappetence, and diarrhea, with or without tenesmus. Less commonly, dogs can present in hypovolemic shock with marked abdominal distension and/or pain [1, 4, 5, 6]. Colonic torsion has been described in dogs with previous gastric dilatation‐volvulus that underwent gastropexy. In approximately half of these cases, large intestinal entrapment and strangulation around the previous gastropexy site was found at the time of abdominal exploratory surgery [7].

Schematic illustration of blood supply to the colon. Photo depicts right lateral abdominal radiograph following barium enema.

      Hypovolemia is corrected with intravenous crystalloid therapy (20–30 ml/kg given over 15–20 minutes, repeated as necessary based on patient clinical status). Early pain control should be considered in patients with abdominal discomfort. The author prefers an opioid analgesic (methadone 0.1–0.2 mg/kg intravenously, IV, or fentanyl 2–5 μg/kg IV). A combination of cefazolin (22 mg/kg IV) and metronidazole (10 mg/kg IV) or cefoxitin (30 mg/kg IV) is recommended in anticipation of colonic surgery due to the likely contaminants in this region of the intestinal tract (coliforms, anaerobes). The first dose of antibiotics should be administered approximately 30 minutes before the surgical incision is made; dosing should be repeated every 90 minutes intraoperatively. For patients diagnosed with colonic perforation and septic peritonitis preoperatively, broad‐spectrum antimicrobial therapy should be initiated as soon as possible (ampicillin and sulbactam 30 mg/kg IV, enrofloxacin 10 mg/kg IV, and metronidazole 10 mg/kg IV is a common protocol).

      Any ischemic or non‐viable region of colon should be resected. The colon should be carefully packed off from the remainder of the abdomen using moist laparotomy sponges. Any feces present within the lumen of the colon should be milked orad and aborad, away from the resection site, and kept in place by non‐crushing forceps (Doyens) to minimize the risk of contamination during the procedure. The author recommends placing the non‐crushing forceps approximately 3 cm orad and aborad to the line of transection to facilitate the anastomosis procedure. Crushing (Carmalt) forceps are placed to isolate the length of colon to be resected. Ligation of individual vasa recta supplying the wall of the colon to be resected, rather than ligation of the main vascular branches, is recommended to help preserve blood supply to the remaining bowel. This can be done with small monofilament suture material, a vessel sealing device, or hemoclips. After resection of the non‐viable colon, anastomosis is performed. The author prefers a sutured anastomosis with either 3‐0 or 4‐0 polydiaxonone. Simple interrupted sutures should be placed at the mesenteric and antimesenteric borders, making sure to engage the submucosa which serves as the holding layer. Due to mesenteric fat obscuring the view of the bowel wall, it is recommended that all sutures along the mesenteric border be preplaced prior to tightening. Subsequently, the sides of the anastomosis are sutured with a simple interrupted or simple continuous, appositional suture pattern. The site should be leak tested with a 25‐gauge needle and sterile saline to assess for any overt suturing errors. The rent in the mesocolon is sutured closed with 4‐0 monofilament absorbable suture material in a simple interrupted or continuous pattern.

Photo depicts intraoperative photograph of a colonic torsion.
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