title: Factors affecting stone-free rate and complications of percutaneous nephrolithotomy for treatment of staghorn stone.
abstract: OBJECTIVE
  To determine factors affecting the stone-free rate and complications of percutaneous nephrolithotomy (PNL) for treatment of staghorn stones.
  
  
  METHODS
  The computerized database of patients who underwent PNL for treatment of staghorn stones between January 2003 and January 2011 was reviewed. All perioperative complications were recorded and classified according to modified Clavien classification system. The stone-free rate was evaluated with low-dose noncontrast computed tomography (CT). Univariate and multivariate statistical analyses were performed to determine factors affecting stone-free and complication rates.
  
  
  RESULTS
  The study included 241 patients (125 male and 116 female) with a mean age of 48.7 ±14.3 years. All patients underwent 251 PNL (10 patients had bilateral stones). The stone-free rate of PNL monotherapy was 56% (142 procedures). At 3 months, the stone-free rate increased to 73% (183 kidneys) after shock wave lithotripsy. Independent risk factors for residual stones were complete staghorn stone and presence of secondary calyceal stones (relative risks were 2.2 and 3.1, respectively). The complication rate was 27% (68 PNL). Independent risk factors for development of complications were performance of the procedure by urologists other than experienced endourologist and positive preoperative urine culture (relative risks were 2.2 and 2.1, respectively).
  
  
  CONCLUSIONS
  Factors affecting the incidence of residual stones after PNL are complete staghorn stones and the presence of secondary calyceal stones. Complications are significantly high if PNL is not performed by an experienced endourologist or if preoperative urine culture is positive.
authors.affiliation: Urology Department, Urology and Nephrology Center, Mansoura University, Mansoura, Egypt. ar_el_nahas@yahoo.com
authors.forename: Ahmed R
authors.initials: AR
authors.lastname: el-Nahas
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Eraky
authors.forename: Ahmed A
authors.initials: AA
authors.lastname: Shokeir
authors.forename: Ahmed M
authors.initials: AM
authors.lastname: Shoma
authors.forename: Ahmed M
authors.initials: AM
authors.lastname: el-Assmy
authors.forename: Nasr A
authors.initials: NA
authors.lastname: el-Tabey
authors.forename: Shady
authors.initials: S
authors.lastname: Soliman
authors.forename: Ahmed M
authors.initials: AM
authors.lastname: Elshal
authors.forename: Hamdy A
authors.initials: HA
authors.lastname: el-Kappany
authors.forename: Mahmoud R
authors.initials: MR
authors.lastname: el-Kenawy
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000453:epidemiology / Q000601:surgery* / Q000652:urine; D008297:Male; D008875:Middle Aged; D009403:Nephrostomy, Percutaneous / Q000009:adverse effects / Q000379:methods; D011183:Postoperative Complications; D012307:Risk Factors