title: Extracorporeal shock wave lithotripsy of lower calyx calculi: how much is treatment outcome influenced by the anatomy of the collecting system?
abstract: OBJECTIVE
  Extracorporeal shock wave lithotripsy (ESWL) of lower calyx stones has been criticized because of the high incidence of residual fragments. Controversial results have been reported regarding the stone-free rate after ESWL depending on the influence of the collecting system anatomy on stone clearance. Therefore we evaluated our stone-free rate after ESWL of lower calyx stones and searched for correlations to various anatomic parameters of the collecting system.
  
  
  METHODS
  Ninety-six patients with isolated lower calyx stones treated exclusively with ESWL (Dornier HM3) were evaluated 3 mo postoperatively. The results were correlated with the following anatomic parameters of the collecting system as determined from the pretreatment intravenous urography: (1) lower infundibulum width, (2) lower infundibulum length, (3) infundibulopelvic angle, (4) volume of the collecting system. Follow-ups were performed 24 h after ESWL with an abdominal plain film and 3 mo postoperatively with a urography or abdominal plain X-ray together with renal ultrasound.
  
  
  RESULTS
  Three months postoperatively, 68% of all patients were stone free, including 69% of the patients with stones initially < or =1 cm, and 67% of the patients with stones >1 cm. Stone-free patients compared with patients having residual fragments had no significant differences in infundibulum width, infundibulum length, infundibulopelvic angle, or collecting system volume.
  
  
  CONCLUSIONS
  A stone-free rate 3 mo after ESWL of 68% overall justifies ESWL as a possible treatment option for lower calyx stones. Influence of the collecting system anatomy on disintegrate clearance from the lower calyx could not be demonstrated.
authors.affiliation: Department of Urology, University of Bern, Bern, Switzerland. hansjoerg.danuser@ksl.ch
authors.forename: Hansjörg
authors.initials: H
authors.lastname: Danuser
authors.forename: Roger
authors.initials: R
authors.lastname: Müller
authors.forename: Bernard
authors.initials: B
authors.lastname: Descoeudres
authors.forename: Eduard
authors.initials: E
authors.lastname: Dobry
authors.forename: Urs E
authors.initials: UE
authors.lastname: Studer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000473:pathology / Q000628:therapy*; D007670:Kidney Calices / Q000033:anatomy & histology*; D008096:Lithotripsy / Q000379:methods*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D016896:Treatment Outcome