title: Contemporary Management of Struvite Stones Using Combined Endourologic and Medical Treatment: Predictors of Unfavorable Clinical Outcome.
abstract: Struvite stones have been associated with significant morbidity and mortality, yet there has not been a report on the medical management of struvite stones in almost 20 years. We report on the contemporary outcomes of the surgical and medical management of struvite stones in a contemporary series.
  
  
  
  A retrospective review of patients who were treated with percutaneous nephrolithotomy (PCNL) for struvite stones at Duke University Medical Center between January 2005 and September 2012 identified a total of 75 patients. Of these, 43 patients had adequate follow-up and were included in this analysis. Stone activity, defined as either stone recurrence or stone-related events, and predictors of activity were evaluated after combined surgical and medical treatment.
  
  
  
  The study included 43 patients with either pure (35%) or mixed (65%) struvite stones with a median age of 55±15 years (range 21-89 years). The stone-free rate after PCNL was 42%. Stone recurrence occurred in 23% of patients. Postoperatively, 30% of patients had a stone-related event, while 60% of residual stones remained stable with no growth after a median follow-up of 22 months (range 6-67 mos). Kidney function remained stable during follow-up. Independent predictors of stone activity included the presence of residual stones >0.4 cm(2), preoperative large stone burden (>10 cm(2)), and the presence of medical comorbidities (P<0.05).
  
  
  
  Struvite stones can be managed safely with PCNL followed by medical therapy. The majority of patients with residual fragments demonstrated no evidence of stone growth on medical therapy. With careful follow-up and medical management, kidney function can be maintained and stone morbidity can be minimized. Initial large stone burden, residual stones after surgery, and associated medical comorbidities may have deleterious effect on stone recurrence or residual stone-related events.
authors.affiliation: 1 Division of Urologic Surgery, Duke University Medical Center , Durham, North Carolina.
authors.forename: Muhammad Waqas
authors.initials: MW
authors.lastname: Iqbal
authors.affiliation: 1 Division of Urologic Surgery, Duke University Medical Center , Durham, North Carolina.
authors.forename: Ramy F
authors.initials: RF
authors.lastname: Youssef
authors.affiliation: 1 Division of Urologic Surgery, Duke University Medical Center , Durham, North Carolina.|2 Department of Urology, Johannes Gutenberg University Mainz , Mainz, Germany .
authors.forename: Andreas
authors.initials: A
authors.lastname: Neisius
authors.affiliation: 1 Division of Urologic Surgery, Duke University Medical Center , Durham, North Carolina.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Kuntz
authors.affiliation: 1 Division of Urologic Surgery, Duke University Medical Center , Durham, North Carolina.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Hanna
authors.affiliation: 1 Division of Urologic Surgery, Duke University Medical Center , Durham, North Carolina.
authors.forename: Michael N
authors.initials: MN
authors.lastname: Ferrandino
authors.affiliation: 1 Division of Urologic Surgery, Duke University Medical Center , Durham, North Carolina.
authors.forename: Glenn M
authors.initials: GM
authors.lastname: Preminger
authors.affiliation: 1 Division of Urologic Surgery, Duke University Medical Center , Durham, North Carolina.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Lipkin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D019355:Calcium Citrate; D002752:Chlorthalidone; D015897:Comorbidity; D004232:Diuretics / Q000627:therapeutic use; D004791:Enzyme Inhibitors / Q000627:therapeutic use; D005260:Female; D006801:Humans; D006877:Hydroxamic Acids / Q000627:therapeutic use; D007669:Kidney Calculi / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009403:Nephrostomy, Percutaneous / Q000379:methods*; D011183:Postoperative Complications / Q000453:epidemiology; D019357:Potassium Citrate / Q000627:therapeutic use; D012008:Recurrence; D012189:Retrospective Studies; D017693:Sodium Bicarbonate; D000069877:Struvite; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D004232:Diuretics; D004791:Enzyme Inhibitors; D006877:Hydroxamic Acids; C006358:acetohydroxamic acid; D017693:Sodium Bicarbonate; D000069877:Struvite; D019357:Potassium Citrate; D019355:Calcium Citrate; D002752:Chlorthalidone