COMPLICATED DIVERTICULITIS AND PELVIC RADIATION LEADING TO COLONIC STRICTURE, COLORECTAL FISTULA AND ANAL STENOSIS

Objectives: The purpose of this case study is to highlight a rare case of sigmoid colon to rectal fistula

Methods: 66 year-old male presented to the emergency department with a 3 week history of abdominal pain and watery diarrhea. Medical history was significant for diverticulosis and B cell lymphoma, completed regimen of chemotherapy 2 months prior to admission and palliative radiation to the low lumbar spine for metastasis. CT abdomen and pelvis showed narrowing of the sigmoid colon and a 2 x 3.2 cm contrast and gas filled extraluminal collection anterior to the rectum tethering the rectum and sigmoid colon. The patient was admitted for IV antibiotics. Colonoscopy noted an anal stricture, open fistula tract in the low rectum, and high-grade obstruction of the sigmoid colon of unknown etiology.
In the operating room, the patient had a 1 cm fistula in the lower aspect of the anterior surface of the rectum. The quality of the tissue in the anterior rectum precluded a suture repair. A Hartman’s pouch was constructed. The final pathology was perforated diverticulitis.

Results: Diverticular disease is common in the western countries and is a significant healthcare system burden. Although 80% to 85% of patients with diverticulosis are asymptomatic, approximately 15% will present symptomatic diverticulosis (diverticular disease) but without inflammation and 10% to 20% will suffer from acute diverticulitis. Complicated diverticular disease accounts about 25% of cases, characterized by either abscesses or fistula formation, obstruction, peritonitis and sepsis. Fistulas occur in 2% of patients with complicated diverticular disease. The formation of the fistula results from a local inflammatory process that results in an abscess, which spontaneously decompresses by perforating into an adjacent structure or through the skin. The fistulous tract is commonly single, but multiple tracts are found in 8% of patients.
Complicated diverticular disease can harbor malignancy. The risk of malignancy was 11% in patients with complicated diverticulitis and was 0.7% in those with uncomplicated diverticulitis. In situations where diverticulitis is complicated by fistula formation, obstruction, or stricture, elective or semi-elective resection is generally recommended to provide symptomatic relief.

Conclusion: To date there have been no cases reported in literature describing colon-to-rectum fistula. It is important to consider the development of complex diverticular disease in patients with history of pelvic radiation. Clinical practice should evaluate the risk factors specific to each patients and identify those who would benefit from early surgical management.