S2042 Hydronephrosis: An Unusual Complication of Diverticular Abscess

Abstract

Introduction: Acute diverticulitis is inflammation due to microperforation of diverticulum in the colon. Ureteral complications from inflammatory bowel disease and colon cancer have been extensively documented, however, hydronephrosis as a complication of diverticulitis is rarely reported. We present a case of a patient with a diverticular abscess who developed left-sided hydronephrosis. Case Description/Methods: A 40-year-old man with a past medical history of laparoscopic cholecystectomy presented with left lower quadrant cramping abdominal pain for 2 weeks. He endorsed constipation for 3 months but denied other symptoms. His physical examination was significant for a palpable phlegmon in the left lower quadrant with mild tenderness to palpation. Laboratory values revealed hemoglobin of 11.4 g/dl, platelet count of 499 k/ul and unremarkable basic metabolic panel. Computed tomography (CT) scan of the abdomen with contrast revealed severe sigmoid diverticulitis and perisigmoid abscess measuring 6 x 2.6 cm (Figure A). It further revealed moderate left hydronephrosis with narrowing of the ureter, concerning for external ureteral compression by the diverticular abscess (Figure B). After multidisciplinary discussion with interventional radiology, urology, and surgery, recommendation was made to undergo surgical intervention after the resolution of acute diverticulitis. The patient was treated with intravenous antibiotics with symptomatic relief and discharged with plan for outpatient surgery. The patient was unfortunately lost to follow-up. He presented 3 months later with perforated diverticulitis, persistent hydronephrosis, colovesical and colocutaneous fistula requiring exploratory laparotomy and repair. His surgical pathology was negative for malignancy and revealed severe diverticulitis. Patient was discharged home in stable condition. Discussion: Ureteral complications in diverticulitis can occur due to the close anatomical location of the left ureter to the descending and sigmoid colon. Common urologic complications include the development of enterovesical fistulas and urinary calculi and obstruction. Physicians should be aware of this association to ensure a repeat CT scan is performed 4-6 weeks after acute diverticulitis to document resolution. Figure 1.: A. CT scan of the abdomen revealing 60.1 x 26.3 mm diverticular abscess. B. CT scan of the abdomen showing left hydronephrosis and dilation of the ureter.