eP312 - A Case of Heterotopic Gastric Mucosa in the Rectum

Purpose/Background: Heterotopic gastric mucosa (HGM) is a rare finding that has been seen at all levels of the GI tract including the tongue, esophagus, duodenum, pancreas, biliary system, small bowel, large bowel and anus. HGM of the rectum was first identified in 1939 and as of 2022, approximately 94 cases of HGM in the rectum and anus have been mentioned in the literature. Due to its rare nature and varying presentation, approaches to the management of HGM continues to evolve. Our patient underwent a minimally invasive transanal excision (TAMIS) which has not been previously described in the literature for this particular pathology.Methods/Interventions: A 49-year-old gentlemen presented to his gastroenterologist endorsing a recent episode of coffee ground emesis, difficulty swallowing, and regurgitation. He also endorsed persistent diarrhea and general abdominal uneasiness. His abdominal discomfort had been present for many years and was initially thought to be due to cholelithiasis, however, his symptoms persisted despite cholecystectomy. He subsequently underwent an upper endoscopy and colonoscopy which demonstrated a 18 mm mucosal nodule in the rectum which was then biopsied and found to be heterotopic gastric mucosa. He elected to proceed to surgery. A TAMIS Alexis port was placed and secured, the transanal space was then insufflated to 20 mmHg, and a laparoscopic camera was inserted. The lesion was identified posteriorly and the lesion was demarcated with a 1-2 cm margin using a thermoenergy device. A full-thickness excision was performed down to the perirectal fat. Once removed, the defect was closed in a running fashion. He was discharged home the same day.Results/Outcomes: At follow-up one month later, his symptoms of heartburn, diarrhea, and abdominal discomfort had abated.Conclusion/

Discussion: HGM of the rectum is associated with hematochezia, anal pain, altered bowel habits, bloating, abdominal discomfort, and cramping. It is often asymptomatic and an incidental finding on colonoscopy. It continues to be a rare finding in the hindgut in comparison to the foregut and midgut where prevalence ranges from 0.1% to 11%. Current management options consist of endoscopic mucosal resection (EMR), transanal diverticulectomy or mucosectomy, or conservative management. Surgical excision is preferred in cases of rectal duplication, ulceration, fistula, or perforation, and surgically resected lesions are typically larger (median 25 mm) compared to endoscopically resected lesions (median 20 mm). Despite the differing methods of removal, on an average follow-up of 22 months, recurrent symptoms were not often seen. Although no formal guidelines currently exist for the management of HGM in the rectum, its removal should be considered given the minimal risk of malignant degeneration, effect on quality of life, and lack of significant complications resulting from intervention. Our approach using TAMIS should be considered in future cases given its utilization of a laparoscopic approach as it provides both great visualization and precision."Rectal Lesion on Colonoscopy

18 mm mucosal lesion located in the rectum on Colonoscopy
Rectal Lesion on Laparoscopy via Transanal Minimally Invasive Approach (TAMIS)

Demarcated Lesion on Laparoscopy with 1-2 cm margin
Full-thickness removal of lesion

A Full-thickness excision was performed down to the perirectal fat
Closure of Defect

The defect was then closed in a running fashion "