Debridement and primary closure of a mesenteric duodenal perforation in a dog

Abstract A 7‐year‐old male mixed intact breed dog was presented with a 6‐day history of lethargy and anorexia. A linear foreign body was diagnosed and an exploratory laparotomy performed. The foreign body was pushed orad and removed via gastrotomy. Two mesenteric duodenal perforations were found: one at the level of the common bile duct and a second at the duodenal flexure. Both lesions were debrided and primarily closed in a simple interrupted appositional pattern. A gastrostomy tube and closed suction drain were placed routinely. The dog recovered without complications and ate voluntarily the first day postoperatively. The drain and gastrostomy tube were removed without incident at 4 and 15 days, respectively. Five months postoperatively the dog was reported to be clinically normal. Debridement and primary closure may represent an alternative to more extensive surgery with rerouting for duodenal perforations in select cases.


INTRODUCTION
The orad section of the duodenum has specific anatomical surgical considerations, due to the common bile duct and pancreatic connecting to the intestinal lumen as well as the proximity of the pancreatic ducts.
Removal of a lesion in the proximal duodenum close to the pylorus would necessitate a pylorectomy, proximal duodenectomy and biliary rerouting via a cholecystoenterostomy (Walter et al., 1985). These procedures have been described as having a high morbidity and mortality rate in the veterinary literature. This was consolidated by the author's personal experience with a negative outcome of a Billroth II. Cholecystoenterostomy alone has been associated with hepatic abscesses, pancreatitis, vomiting as well as acquired portosystemic shunts in dogs (Papazoglou et al., 2008). Surgical diseases of this segment might therefore lead to a different decision making process than those further aborad due to concerns regarding patient morbidity and/or mortal-    The physical exam was unremarkable, the incision site had healed (no signs of inflammation were noted) and no discomfort was noted on abdominal palpation. Body weight was 24 kg (12% body weight loss from initial presentation). The owner reported normal appetite and bowel movements and no episodes of vomiting or regurgitation, and the gastrostomy tube was removed at this time. A telephone follow-up was performed 5 months postoperatively, and the client reported the dog to be clinically normal.

DISCUSSION
Lesions in the proximal duodenum might require pylorectomy and biliary rerouting if the major and minor duodenal papilla and common bile duct are involved. This was considered as the initial option, but not performed due to potential perioperative complications and concerns for long-term impact on the dog's health. Perioperative complications of pylorectomy can include septic peritonitis, anorexia, vomiting coagulated blood or bilious vomiting, reflux, acute gastric rupture and gastritis (Ahmadu-Suka et al., 1988). Mortality rate of pylorectomy has been reported as 25% mortality within 14 days postoperatively (Eisele et al., 2010). Long-term health issues have been described as decreased body mass from malabsorption and maldigestion, gastrointestinal ulcers, duodenal obstruction and gastritis (Ahmadu-Suka et al., 1988) as well as afferent loop syndrome (Monnet, 2020). Of 15 dogs that underwent a cholecystoenterotomy procedure, 9 died within 20 days, and of the remaining 9 dogs, 2 were lost to follow-up after 6 days (Papazoglou et al., 2008). A total of 11 dogs had died, for 8 of whom the cause of death was directly related to the surgery or the underlying hepatobiliary disease.
Risks of debridement and primary closure range between luminal narrowing if too aggressive and dehiscence if the debridement did not reach sufficiently healthy tissue. We opted for piecemeal debridement and removing strips of intestinal wall, until such time that the tissue had the subjective appearance of noncompromised intestinal wall during the cut, and bled afterwards. Care was taken during suturing to assess force needed to pass the needle, and whether the suture would appear to 'pull through' the tissue. While a 'waist' was appreciated post repair, this did subjectively not seem enough to cause intestinal obstruction, but might be a concern in smaller dogs and cats. A duodenal sparing surgical option was recently described using a vascularised jejunal graft to close an antimesenteric duodenal defect after wide debridement while avoiding luminal narrowing (Putterman et al., 2019). Given the mesenteric location of the perforation, a debridement wide enough to raise concern about luminal narrowing would also have necessitated biliary rerouting due to the proximity of the common bile duct. We therefore opted for primary closure as opposed to adding a graft to the surgery site, due to increased surgical time, adding a second surgery around the tube being the most common issue (10/11). This reflected the findings in an earlier study on 24 dogs with surgically placed gastrostomy tubes (Hansen et al., 2019). Eight dogs experienced tube related problems: six were minor and did not require tube removal. In two dogs, the tube had migrated into the subcutaneous space, but no intraabdominal leakage or complication was seen in either.
Careful debridement and primary closure of intestinal perforations might provide an alternative surgical option for select cases where morbidity of more complex surgeries may be prohibitive.

CONFLICT OF INTEREST STATEMENT
The authors declare no conflict of interest.

DATA AVAILABILITY STATEMENT
Data sharing is not applicable to this article as no new data were created or analysed in this case report.

ETHICS STATEMENT
The authors confirm that the ethical policies of the journal, as noted on the journal's author guidelines page, have been adhered to. No ethical approval was required as this is a case report where decision making was driving by best clinical practice and with full client consent.