title: Combined electrohydraulic and holmium:YAG laser ureteroscopic nephrolithotripsy of large (greater than 4 cm) renal calculi.
abstract: OBJECTIVE
  Percutaneous nephrolithotripsy is standard treatment for renal calculi larger than 2 cm. Modern flexible ureteroscopes and accessories using the complimentary effects of electrohydraulic lithotripsy and holmium:YAG laser lithotrites can treat large (greater than 4 cm) branched renal calculi in a minimally invasive fashion with similar or superior results. This report is an assessment of the safety and efficacy of ureteroscopic nephrolithotripsy monotherapy for the management of large (greater than 4 cm) branched renal calculi in the community setting.
  
  
  METHODS
  A total of 16 patients with 17 branched renal calculi ranging from 41 to 97 mm (mean 65) in length and 560 to 2,425 mm2 (mean 1,169) in area underwent staged ureteroscopic nephrolithotripsy monotherapy. Obesity (body mass index greater than 30) was present in 81% and 38% were morbidly obese (body mass index greater than 40). An infectious etiology was present in 81% and hard stone components were present in 94%. All patients presented with hematuria, pain and/or recurrent urinary tract infection. Lithotripsy was performed with a single deflection flexible ureteroscope and predominantly electrohydraulic lithotripsy. Laser drilling was used (in 4) to weaken hard stones before electrohydraulic lithotripsy. Low intrarenal pressure was maintained by continuous bladder drainage and placement of a stiff safety wire. Visibility was maintained using manual pulsatile irrigation.
  
  
  RESULTS
  All patients were rendered pain and infection-free. No patient required a blood transfusion and there was no change in serum creatinine. Mobile stone-free status was achieved in 15 of 17 renal units (88%) with a mean of 2.4 stages and 36 of 40 (90%) procedures performed on an outpatient basis. Operative time averaged 49 minutes per stage and 115 minutes per calculus. There were 3 patients admitted for fever and 1 patient (90 years old) admitted for pneumonia 3 days postoperatively. There were also 3 patients with calculi larger than 75 mm who required ureteroscopic management of steinstrasse.
  
  
  CONCLUSIONS
  Staged ureteroscopic nephrolithotripsy of large renal calculi is feasible with low morbidity and stone clearance rates that compare favorably with percutaneous nephrolithotripsy.
authors.affiliation: Kaiser Medical Center, Honolulu, Hawaii 96819, USA. albert.mariani@kp.org
authors.forename: Albert J
authors.initials: AJ
authors.lastname: Mariani
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000535:Aluminum; D005260:Female; D006695:Holmium; D006801:Humans; D007669:Kidney Calculi / Q000473:pathology / Q000628:therapy*; D008096:Lithotripsy / Q000379:methods*; D017602:Lithotripsy, Laser / Q000379:methods; D008297:Male; D008875:Middle Aged; D018666:Ureteroscopy; D015019:Yttrium
chemical_list: C503779:yttrium-aluminum-garnet; D015019:Yttrium; D000535:Aluminum; D006695:Holmium