title: Combined electrohydraulic and holmium:yag laser ureteroscopic nephrolithotripsy for 20 to 40 mm renal calculi.
abstract: OBJECTIVE
  Percutaneous nephrolithotripsy is standard treatment for renal calculi greater than 2 cm. Modern flexible ureteroscopes using the complementary effects of electrohydraulic (EHL) and Ho:YAG laser lithotrites can treat 2 to 4 cm renal calculi in minimally invasive fashion with similar or superior results. We evaluated the safety and efficacy of ureteroscopic nephrolithotripsy for the management of 2 to 4 cm renal calculi in a community setting.
  
  
  METHODS
  Between January 2001 and November 2002 all 15 patients presenting with renal calculi 22 to 42 mm long (mean 33) and 275 to 650 mm in area (mean 396), of whom 40% had infection, underwent flexible ureteroscopic nephrolithotripsy. A total of 13 patients had 3-month followup data. Hard stone components, namely calcium oxalate monohydrate and/or apatite, were present in 13 cases (87%). Treatment principles were the aggressive treatment of infection, EHL stone debulking, Ho:YAG laser lithotripsy to weaken hard stones structurally, manual piston irrigation to maintain visibility, bladder drainage to maintain low intrarenal pressures, minimum 6-hour postoperative observation and physiological passage of stone fragments.
  
  
  RESULTS
  In the 13 patients with 3-month followup data the stone clearance rate was 92% for complete stone free status and 100% for fragments less than 4 mm. This result was achieved at 1 stage in 10 cases 13 (77%) and at 2 to 4 stages in 1 each. Mean procedure time per stage was 47 minutes (range 25 to 90) and total procedure time per patient was 66 minutes (range 25 to 240). There was no significant change in mean preoperative and postoperative hemoglobin (p = 0.87) and creatinine (p = 0.85) in the 16 of 21 procedures for which data were available. Procedures were done on an outpatient basis except in 1 patient, who was hospitalized overnight for the management of preexisting pulmonary problems. One rehospitalization for colic management but no other unplanned emergency department or clinic visits occurred. All patients were rendered infection-free and symptom-free.
  
  
  CONCLUSIONS
  Combined EHL and Ho:YAG laser flexible ureteroscopic lithotripsy can be an effective treatment with low morbidity. As such, it provides an attractive, minimally invasive alternative to percutaneous nephrolithotripsy or open surgery in patients with 2 to 4 cm renal calculi.
authors.affiliation: Departmetn of Urology, University of Hawaii, John A. Burns School of Medicine, Kaiser Medical Center, Honolulu 96819, USA. albert.mariani@kp.org
authors.forename: Albert J
authors.initials: AJ
authors.lastname: Mariani
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000601:surgery*; D008096:Lithotripsy / Q000379:methods*; D017602:Lithotripsy, Laser; D008297:Male; D008875:Middle Aged; D018666:Ureteroscopy