title: Simultaneous versus staged bilateral extracorporeal shock wave lithotripsy: long-term effect on renal function.
abstract: OBJECTIVE
  We determine whether there is a clinically significant difference in the long-term effect on renal function following simultaneous versus staged bilateral extracorporeal shock wave lithotripsy (ESWL).
  
  
  METHODS
  Between July 1986 and October 1995, 360 patients underwent treatment for bilateral renal calculi with ESWL using a Dornier HM-3 lithotriptor. Of the patients 319 had both kidneys treated simultaneously (simultaneous group) and the remaining 41 were treated in a planned, staged fashion (staged group) with the procedures separated by 3 to 20 weeks (mean 6.0). Followup data of at least 1 year were available for 49 men and 30 women (mean age 52.4) in the simultaneous group, and 8 and 12 (mean age 45.1), respectively, in the staged group. Mean stone burden was 0.70 cm.2 on the right and 0.87 on the left side in the simultaneous group, and 1.6 and 1.5, respectively, in the staged group.
  
  
  RESULTS
  Patients with at least 1 calculus greater than 0.5 cm.2 treated simultaneously received a mean of 1,386 shock waves to the right and 1,637 to the left side, and the staged group received a mean of 1,802 and 2,094, respectively. Mean serum creatinine was 1.03 mg./dl. before and 1.04 after treatment (normal 0.7 to 1.4 mg./dl.) in the simultaneous group, representing a mean increase of 0.01 at followup of 1.0 to 10.5 years (mean 3.7), and 0.88 and 0.88, respectively, in the staged group, representing a decrease of 0.005 at followup of 1.0 to 7.2 years (mean 3.2). The effects of simultaneous versus staged ESWL on renal function as measured by serum creatinine were not statistically significant using a multiple regression model which controlled for the effects of stone burden, number of shock waves, patient age, pretreatment serum creatinine and length of followup (p = 0.19).
  
  
  CONCLUSIONS
  There is no clinically apparent difference in the long-term effect on renal function for patients with bilateral renal calculi treated with ESWL in a simultaneous versus staged fashion.
authors.affiliation: Department of Urology, Cleveland Clinic Foundation, Ohio 44195, USA.
authors.forename: A J
authors.initials: AJ
authors.lastname: Pienkny
authors.forename: S B
authors.initials: SB
authors.lastname: Streem
mesh_terms: D000328:Adult; D003404:Creatinine / Q000097:blood; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007668:Kidney / Q000502:physiology*; D007669:Kidney Calculi / Q000628:therapy*; D008096:Lithotripsy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D013997:Time Factors
chemical_list: D003404:Creatinine