title: Percutaneous nephrolithotomy for removal of encrusted ureteral stents: a multicenter study.
abstract: OBJECTIVE
  Encrusted ureteral stents are a challenging endourologic problem. We performed a multi-institutional review of percutaneous nephrolithotomy (PCNL) as primary treatment for encrusted stents.
  
  
  METHODS
  We identified 36 patients who underwent PCNL for treatment of an encrusted stent. A retrospective review was performed to compile details of procedures and outcomes for these patients.
  
  
  RESULTS
  In 36 patients, 38 renal units underwent PCNL for encrusted ureteral stents. The mean patient age was 47.1 years (±16.7), and the female:male ratio was 15:21. Mean stent indwelling time before removal was 28.2 months (±27.8). The reason for long indwelling time was reported in 25 cases; these reasons included "patient unaware stent needed to be removed" (17 cases), pregnancy (2 cases), other comorbidities (3 cases), and patient incarceration (3 cases). In 3 cases, the stent had become encrusted within 3 months of placement. Mean operative time was 162 minutes (±71). There were no major intraoperative complications, and no patients required blood transfusion. Litholapaxy was required for bladder coil encrustations in 22 cases (58%), and ureteroscopy with lithotripsy was required for encrustation of the ureteral portion of the stent in 13 cases (34.2%). Second look percutaneous procedures were required in 13 cases (34.2%). The stent was removed at the time of PCNL without need for concomitant or delayed ureteroscopy and/or cystolitholapaxy in 8 cases (21%). Ultimately, all stents were removed successfully. Patients were rendered stone free according to radiographs in 24 cases (63%).
  
  
  CONCLUSIONS
  In this multicenter review, PCNL is confirmed to be a safe and effective means of addressing the retained and encrusted ureteral stent. PCNL without ureteroscopy or litholapaxy was sufficient in a minority of cases (21%). Adjunctive endourologic modalities are often required, and the surgeon should anticipate the need for concomitant antegrade ureteroscopic laser lithotripsy and/or cystolitholapaxy. Although complete stent removal can be anticipated, residual fragments are not uncommon.
authors.affiliation: 1 Section of Urology, Dartmouth Hitchcock Medical Center, Lebanon , New Hampshire.
authors.forename: Vernon M
authors.initials: VM
authors.lastname: Pais
authors.forename: Ben
authors.initials: B
authors.lastname: Chew
authors.forename: Ojas
authors.initials: O
authors.lastname: Shaw
authors.forename: Elias S
authors.initials: ES
authors.lastname: Hyams
authors.forename: Brian
authors.initials: B
authors.lastname: Matlaga
authors.forename: Ramakrishna
authors.initials: R
authors.lastname: Venkatesh
authors.forename: Jay
authors.initials: J
authors.lastname: Page
authors.forename: Ryan F
authors.initials: RF
authors.lastname: Paterson
authors.forename: Olga
authors.initials: O
authors.lastname: Arsovska
authors.forename: Michael
authors.initials: M
authors.lastname: Kurtz
authors.forename: Brian H
authors.initials: BH
authors.lastname: Eisner
mesh_terms: D000328:Adult; D020878:Device Removal / Q000379:methods*; D005260:Female; D006801:Humans; D008096:Lithotripsy / Q000379:methods*; D017602:Lithotripsy, Laser / Q000379:methods; D008297:Male; D008875:Middle Aged; D009403:Nephrostomy, Percutaneous / Q000379:methods*; D012189:Retrospective Studies; D015607:Stents / Q000009:adverse effects*; D014513:Ureter / Q000601:surgery*; D014514:Ureteral Calculi / Q000601:surgery*; D018666:Ureteroscopy; D013520:Urologic Surgical Procedures / Q000009:adverse effects