EP330 - Colorectal Perforation Following Anorectal Manometry in a Patient with Anal Stenosis Post Rectal Prolapse Repair: A Rare Complication

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Purpose/Background: Anorectal manometry assesses the functional integrity of the rectum and anal sphincters (1). While generally safe, rare complications can occur. Colorectal perforation is a serious but infrequent adverse event following anorectal manometry, documented in a handful of cases (2-4).
We present a rare case of colorectal perforation following anorectal manometry in a patient with anal stenosis after prior rectal prolapse surgeries. Rectal prolapse may recur after surgery. Although perineal proctectomies can be safely repeated, resection procedures may lead to an ischemic segment between two anastomoses unless the previous anastomosis is resected (5).
This case underscores the need for appropriate surgical management of recurrent rectal prolapse and careful patient selection and technique during anorectal manometry.

Methods/Interventions: A 77-year-old female with atrial fibrillation on Pradaxa and a history of rectal prolapse presented with hematochezia and fever. She had previously undergone resection rectopexy in 2006 and perineal proctectomy with sphincteroplasty in 2019 for recurrent rectal prolapse. Following these procedures, she developed an anal stricture and fecal incontinence. Anorectal manometry led to immediate rectal bleeding, prompting an ER visit, and she did not hold her Pradaxa beforehand.
On examination, her vitals were stable, her abdomen was nontender and minimally distended, and there was minor anal bleeding. Labs showed WBC 13.4 and Hgb 10.8. A CT scan revealed air in the retroperitoneum, colon mesentery, and through the mediastinum. Anticoagulation was reversed with Praxbind, and exam under anesthesia with flexible sigmoidoscopy showed disruption of the right lateral rectum 8 cm from the anal verge, covering 30% of the circumference. Nonoperative management was chosen, and she received inpatient antibiotics.

Results/Outcomes: WBC levels normalized, and she was discharged on POD 5 with a low-fiber diet and no antibiotics. A follow-up flexible sigmoidoscopy one month later revealed that the rectal perforation had nearly healed, with only a small area of mucosal disruption. A subsequent sigmoidoscopy 1.5 months later confirmed complete healing with healthy mucosa.

Conclusion/Discussion: Anorectal manometry assesses sphincter contractility, rectal sensation, compliance, reflexes, and defecation coordination (1). Extra caution is needed for patients with prior radiation. Lee et al. advises stopping the study if the patient doesn’t feel maximum sensation at 100cc saline or reports discomfort (2). Zhao et al. suggests limiting inflation to 200cc and enhancing teaching protocols to minimize complications (4).
Prior surgical history is crucial for rectal prolapse surgery. This case involved ischemia and a stricture between two anastomoses from previous repairs. Blood supply between two hindgut anastomoses is tenuous, so a non-resection approach should be considered if resection isn't feasible (6-7). Maintaining blood supply is essential (10).
Extraperitoneal rectal injuries are typically managed conservatively, with proximal diversion recommended in select cases (8). Zhao et al. suggests conservative treatment for stable patients with small perforations and no peritonitis. Larger perforations or those with peritonitis may require surgical intervention (4). ARM-induced colorectal perforations may follow similar treatment guidelines as colonoscopy-induced perforations (4, 9). In this case, the patient's stability and perforation location made nonoperative management effective.