VM107 - Robot-assisted Total Proctocolectomy and Ileal Pouch Anal Anastomosis for Rectal Cancer in a Patient with Familial Adenomatous Polyposis

Purpose/Background: Familial adenomatous polyposis (FAP) is a rare, autosomal dominant inherited disease, characterized by the development of colorectal adenomatous polyposis. FAP is caused by an inherited mutation in the APC gene on chromosome 5q2. Because patients are born with only one functional copy of the gatekeeper gene, loss of the second allele via sporadic mechanisms leads to the rapid development of hundreds to thousands of colorectal adenomas. The risk of developing colorectal cancer is nearly 100% by the age of 40. Managing FAP involves regular surveillance and prophylactic colectomy. The goal of FAP treatment is to remove or limit the colorectal cancer risk while maximizing quality of life. As colorectal cancer is near certain, prophylactic surgical removal is the mainstay of treatment.

For patients without evidence of rectal cancer, surgical options include colectomy with ileorectal anastomosis (IRA) or total proctocolectomy (TPC) with or without restoration of the intestinal tract; both procedures are associated with unique oncologic and functional implications. Morbidity and quality of life should be considered when deciding the extent of surgery.

For patients with rectal cancer, the decision-making is more complicated. For patients with early-stage rectal cancer, total proctocolectomy or IPAA can be chosen as per the patient’s preference. However, if the rectal cancer is locally advanced and radiotherapy is required, the risk of pouch loss must be considered.

Methods/Interventions: A 43-year-old male with history of FAP was diagnosed with T3N2 moderately differentiated rectal adenocarcinoma, on surveillance colonoscopy. He underwent total neoadjuvant therapy with complete response. No residual tumor or lymphadenopathy were noted on re-staging magnetic resonance imaging (MRI). Given history of FAP and high risk of recurrence, and after discussion of pouch failure risk due to pelvic radiation, he was scheduled for robot-assisted total proctocolectomy with ileo-anal pouch anastomosis and diverting loop ileostomy.

Results/Outcomes: The operative time was 6 hours, 15 minutes, and the estimated blood loos was 100cc. Final pathology reported no residual carcinoma and 24 negative lymph nodes harvested. The postoperative course was characterized by high ostomy output which required loperamide TID for control, and discharge occurred on postoperative day 9. Contrast enema study was performed 10 weeks following surgery and demonstrated no J-pouch leak or stricture. The patient’s diverting loop ileostomy was subsequently reversed, and at 6 month follow up, no complications were reported. The patient referred 4-5 bowel movements per day.

Conclusion/Discussion: Robot-assisted total proctocolectomy with diverting loop ileostomy is a safe and effective technique for the oncologic management of rectal cancer in patients with history of FAP, even with history of pelvic radiation.