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Perforation of a Long-standing Ileocolonic Anastomosis During Colonoscopy

Colonoscopy is a valuable diagnostic and therapeutic procedure. Colonic perforation is a serious complication of colonoscopy that must be promptly recognized to limit morbidity and mortality. We present a 69-year-old woman who, during colonoscopy, had a perforation secondary to barotrauma of a long-standing ileocolonic anastomosis proximal to the point of colonoscopic intubation. To our knowledge, this is the first case report of a perforation of a well-established anastomosis proximal to the point of endoscope intubation during colonoscopy.


Introduction
The risks associated with colonoscopy are well-recognized and most commonly include cardiopulmonary events and hemorrhage. Perforation is an uncommon complication, but must be promptly recognized to limit morbidity and mortality. Perforation can occur due to mechanical forces, therapeutic interventions, or barotrauma. 1 The incidence of perforation ranges from 0.016% for diagnostic procedures to as high as 5% for therapeutic colonoscopies. 2 More than half of perforations occur in the rectosigmoid, and about 10-20% in the cecum. 3 Risk factors include advanced patient age (>60 years), female sex, polypectomy, diverticulosis, prior abdominal or pelvic surgery, low-volume endoscopist, severe and active inflammatory bowel disease, and use of systemic steroids. 4,5 Dehiscence of an anastomosis related to endoscopy is rare, even early in the postoperative period. 6

Case Report
A 69-year-old woman with pancolonic ulcerative colitis for 31 years presented for colonoscopy to evaluate 6 weeks of painless, non-bloody diarrhea. She had maintained remission for the past 10 years on mesalamine. Medical history included migraines, hypothyroidism, acid reflux, aortic stenosis, and chronic obstructive pulmonary disease. Abdominal surgeries included hysterectomy, cholecystectomy, and ileocecectomy 4 years ago for small bowel obstruction due to adhesions. Pathologic review showed viable mucosa without any histologic changes. Additional daily medications included zolpidem, aspirin, metoprolol, mirabegron, omeprazole, levothyroxine, and topiramate. Physical exam was notable for an obese abdomen with well-healed scars. She had normal thyroid-stimulating hormone, IgA, fecal calprotectin, and negative tissue transglutaminase antibody IgA. Stool culture was negative for Campylobacter, Salmonella, Shigella, and Clostridium difficile. Immediately post-procedure, the patient experienced severe abdominal pain and distension. Abdominal x-ray showed pneumoperitoneum and emergent laparotomy was performed ( Figure 1). A pinhole perforation was identified at the "crotch" of the stapled ileocolonic anastomosis with a large amount of pneumoperitoneum. There was no feculent material within the abdomen, and the ileum and colon appeared normal. The ileocolonic anastomosis was resected and a sewn side-to-end terminal ileum to midtransverse colon anastomosis performed. Pathological evaluation of the resected ileocolonic anastomosis showed a focus of submucosal myxoid degeneration with organizing fibrosis and rare multinucleated giant cells in the colon; the overlying colonic mucosa was normal (Figures 2 and  3). No granulomas or infectious organisms were identified. The postoperative course was complicated by atelectasis and obesity hypoventilation syndrome. She was gradually weaned from supplemental oxygen and discharged on 6 days later.

Discussion
Colonic perforations during colonoscopy can be managed endoscopically, surgically, or medically. 7 Nonsurgical management may be possible in afebrile, hemodynamically stable patients without severe abdominal pain. Nonsurgical management includes bowel rest, intravenous fluids and antibiotics, and serial evaluation. Surgical management is necessary for patients presenting with peritonitis, large perforations, or after failed nonsurgical management. 8 Surgical approaches include primary suturing of perforation, but most favor colonic resection with either primary anastomosis or ostomy creation. 2 Recent reports have proven the safety and efficacy of laparoscopic approaches to colonoscopic perforation. [9][10][11] Endoscopic clip closure of an immediately recognized perforation may prevent the need for surgical repair 12 ; however, clinical deterioration after clip repair and medical management necessitates immediately referral for surgery. 13   To our knowledge, this is the first case report of a perforation of a well-established anastomosis proximal to the point of endoscope intubation during colonoscopy. The cause of this perforation was likely barotrauma. Barotrauma causes linear mucosal tears that may lead to full thickness tears and perforation. 8 Insufflation to pressures above 140 mm Hg are likely to cause perforation. 14 During insufflation, the diameter of the right colon, which is thin walled and at the highest risk for barotrauma, increases at a greater rate than the left colon. 15 While colonoscopic insufflation with CO 2 causes less abdominal pain and distension, there is no reduced risk for adverse events, including perforation. 16 The etiology of the defect in the resected specimen in this case was likely due to subclinical chronic submucosal inflammation. Air insufflation during colonoscopy led to opening of the defect and subsequent perforation. Technical difficulty and prolonged procedure duration likely increased the risk for barotrauma.

Disclosures
Author contributions: All authors participated in writing the case report. B. Phillips and D. Kastenberg edited the manuscript. D. Kastenberg is the article guarantor.
Financial disclosure: D. Kastenberg has received research support from Ferring and is a consultant for Salix.
Informed consent was obtained for this case report.