title: Experience with instrumental chemolysis for urolithiasis.
abstract: OBJECTIVE
  We describe a more efficient solution for calcium magnesium stones, an irrigation technique devised by us, and the indications for and results of our 20-year experience with direct renal or ureteral chemolysis.
  
  
  METHODS
  Renal and ureteral perfusion is performed with 2 coaxial catheters (where the interspace is 1-way circulation), a normal ureteral catheter to a nephrostomy tube or, if the ureter is impractical, a nephrostomy tube after inserting it in a thin catheter achieving coaxial circulation. The perfusion operates by gravity with continuous flow maintaining a negative pressure in the cavities and keeping the circuits sealed during treatment. All equipment is mounted on a mobile support which the patient can take anywhere in the hospital.
  
  
  RESULTS
  During the last 20 years 8 cystine stones and 20 "difficult" stones have been completely dissolved and the volume of 39 staghorn struvite stones has been reduced an average of up to 80% before 1 or 2 final lithotripsy sessions without significant side effects. Small fragments remained in the inferior calices in only 2 cases.
  
  
  CONCLUSIONS
  Chemolysis is useful for eliminating cystine stones as well as for cases in which lithotripsy or endourology is considered difficult or risky. Furthermore, chemolysis proved to be a useful method for reducing staghorn stones before performing lithotripsy.
mesh_terms: D000085:Acetates / Q000627:therapeutic use*; D000293:Adolescent; D000328:Adult; D000368:Aged; D004492:Edetic Acid / Q000627:therapeutic use*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007669:Kidney Calculi / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D012996:Solutions; D014514:Ureteral Calculi / Q000628:therapy*
chemical_list: D000085:Acetates; D012996:Solutions; C028257:nitroacetic acid; D004492:Edetic Acid