title: Effect of high shock number on acute complication development after extracorporeal shockwave lithotripsy.
abstract: OBJECTIVE
  We assessed whether high shock number is associated with higher rates of acute complication development after extracorporeal shockwave lithotripsy (SWL).
  
  
  METHODS
  A retrospective chart review of 372 patients who underwent 436 SWL procedures at 24 kV using a Medstone STS-T lithotripter (Medstone International Inc., Aliso Viejo, CA) was conducted. Complications occurred within 4 weeks of SWL. Treatments were split into three cohorts based on shock number (<2400, 2401-4000, and >4000). Postoperative sequelae of patients who were stone free and those with residual stone were studied separately. Chi-square tests were used to evaluate the relationship between shock number cohort and postoperative complication development.
  
  
  RESULTS
  SWL treatments recorded for each cohort were 158 (37.4%), 145 (34.4%), and 119 (28.2%), respectively. The short-term complication rate when SWL was successful was 8.3% overall. Complication rate for each cohort was 9.5% (11), 7.8% (5), and 7.2% (7), respectively. When SWL was successful, statistical analysis revealed no significant difference between complication rates and shock number cohort (P=0.63). Complications in patients with a residual stone occurred after 41.4% of treatments and trended upward with shock number cohort, but did not reach statistical significance (P=0.84).
  
  
  CONCLUSIONS
  At high voltage, high shock number was not shown to cause higher rates of short-term postoperative complications, as experienced by patients, when SWL was successful or resulted in a residual stone, yet complication rates associated with residual stone burden were approximately five times as common. Forgoing a higher shock number in the presence of a residual stone may therefore increase the risks of sequelae immediately after SWL.
authors.affiliation: Section of Urology, Georgia Health Sciences University, Augusta, Georgia, USA.
authors.forename: Miriam
authors.initials: M
authors.lastname: Hadj-Moussa
authors.forename: James A
authors.initials: JA
authors.lastname: Brown
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007484:Iowa / Q000453:epidemiology; D007669:Kidney Calculi / Q000628:therapy*; D008096:Lithotripsy / Q000009:adverse effects* / Q000379:methods; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014514:Ureteral Calculi / Q000628:therapy*; D014555:Urination Disorders / Q000453:epidemiology / Q000209:etiology*; D055815:Young Adult
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