Retroperitoneal fibrosis (RPF) is an uncommon disease complicated by ureteral entrapment. Its etiology includes several medications, periaortic inflammation, abdominal and retroperitoneal operations, radiotherapy, and malignancy. We present 18 patients, 14 of whom developed RPF after surgery and radiotherapy.

During the past 12 years, we treated 7 women and 11 men. The diagnosis was based on intravenous urography, retrograde pyelography, and computed tomography features. Computed tomography-guided or intraoperative biopsies were taken to differentiate benign from malignant fibrosis. In all patients, percutaneous stent nephrostomies or internal stents were inserted before surgery. The operation included ureterolysis with an omental flap or ureteral reimplantation. Follow-up included renal function tests, intravenous urography, and computed tomography.

The mean patient age was 57.3 years (range 36 to 85). Fourteen patients developed RPF after abdominal or retroperitoneal surgery. Three had primary RPF and one malignant RPF due to metastatic disease. Six patients also underwent radiotherapy. The mean time between the insults to the diagnosis of RPF was 18.6 months (range 1 to 96). Ten patients had bilateral obstruction. Fourteen patients underwent surgery and four were treated with stenting only. Of the 14 patients who underwent surgery, 10 had a normal intravenous urogram postoperatively and 4 had decreased function of the formerly obstructed kidney. In 1 patient, re-entrapment of the ureter appeared owing to pelvic recurrence of tumor. At last follow-up, 1 patient waits with stents. The mean follow-up time was 22 months (range 4 to 52).

The etiology of RPF varies. The unique feature of our series was the high incidence of patients who developed RPF after surgery and radiotherapy to the retroperitoneum. Nephrostomy drainage and ureteral stenting facilitated surgery. Ureterolysis combined with wrapping the ureter with an omental flap or re-implantation ensured good anatomic and functional results.