Abstract:

To investigate the initial experience of coated metal ureteral stent (CMUS) for treatment of pelvic lipomatosis induced hydronephrosis (PLH). The clinical and follow-up data of 8 patients who were diagnosed as PLH treated with CMUS in Peking University People's Hospital from August 2018 to February 2021 were retrospectively analyzed. Inclusion criteria included: Imaging evidence of excessive adipose tissue around the bladder in the pelvic cavity, bladder elevation in an "inverted pear shape", and bladder wall thickening; Cystoscopy indicated follicular hyperplasia of bladder mucosa and biopsy pathology indicated glandular cystitis; Unilateral or bilateral hydronephrosis and ureteromegaly. Exclusion criteria included: Ureteral atresia; Recurrent obstruction of the bladder outlet. Preoperative baseline data included age, gender, serum creatinine, pelvis width and ureteric stent symptoms questionnaire (USSQ) score. Intraoperative data included the location and length of ureteral stenosis observed by retrograde urography. Postoperative follow-up data included serum creatinine, pelvis width, and USSQ score. In the study, 8 patients (11 sides) with PLH were all male, with an average age of (38.7±8.6) years. Unilateral hydronephrosis was found in 5 cases and bilateral hydronephrosis in 3 cases. Preoperative mean serum creatinine was (90.0±10.3) μmol/L, and the mean renal pelvis width was (3.0±1.5) cm. The lower ureteral stricture was found in all cases, and the mean stricture length was (1.9±0.9) cm. Before operation, 3 patients had ureteral Double-J stents, with USSQ scores of 97.0, 68.0 and 100.0, respectively. Five patients underwent retrograde CMUS stenting, and 3 patients retrograde and antegrade. At the last follow-up, the average serum creatinine was (82.0±11.1) μmol/L and the mean renal pelvis width was (1.9±0.5) cm, which were significantly lower than those before operation (t=3.12, P=0.02; t=3.23, P=0.02). In the 3 patients with Double-J stent before surgery, the USSQ scores were 87.0, 62.0 and 89.0, respectively, which were significantly improved after CMUS stenting. The average follow-up time was (10.0±6.3) months. During the follow-up, 1 patient developed CMUS related symptoms, and no stent-associated infection and stent encrustation were found. In one case, the stent migrated to the bladder 3 months after operation, and the hydronephrosis disappeared after 3 months follow-up. CMUS stenting for treatment of PLH has certain efficacy and safety, which can explore a new therapeutic method for the long-term treatment of PLH.

Key words: Coated metal ureteral stent, Pelvic lipomatosis, Hydronephrosis