title: Citric acid (solution R) irrigation in the treatment of refractory infection (struvite) stone disease: is it useful?
abstract: OBJECTIVE
  Citric acid, in varying concentrations, has been used in the dissolution treatment of struvite renal calculi. Solution R (Uro-trainer), which contains 6% citric acid, is a solution licensed for use in the management of struvite stone disease in the UK. We report our experience.
  
  
  METHODS
  23 kidneys in 22 patients (10 male and 12 female patients, mean age 45, range 15-60 years) underwent solution R irrigation following debulking of the stone with percutaneous nephrolithotomy (n = 20), ureteroscopy and shock wave lithotripsy (n = 2) combined with open procedures (n = 4) between 1994 and 1998. The original stone configuration consisted of 14 staghorn, 4 partial staghorn and 5 large burden stones. Irrigation was performed through a nephrostomy tube (n = 20) or in a retrograde fashion (n = 3) using a closed infusion pump system (40 ml/h). The response to treatment was checked using a nephrostogram and/or plain X-ray.
  
  
  RESULTS
  In 6 (26%) kidneys, after an average duration of 2 (1-5) days, irrigation had to be abandoned due to loin pain, leak or sepsis. The average duration of irrigation was 6.4 (1-20) days. At the end of irrigation, a total of 4 (17.4%) kidneys had complete radiographic clearance, while the stone was reduced to calyceal dust in 3 (13%). Partial response was seen in 11 (47.8%) and no response in 5 (21.8%) kidneys. Following additional alternative intervention(s) in 6 (26%) kidneys (4 with partial and 2 with no response) further clearance was achieved in 3 (13%) and calyceal dust status in 3 (13%). The response was better if the stone was reduced to less than 10mm prior to irrigation. At the mean follow-up of 2.44 (1-4) years, of 13 kidneys with stone clearance or calyceal dust, 9 suffered recurrence or re-growth, 5 of which required further interventions. Only 4 (17.4%) of 23 kidneys remained stone free.
  
  
  CONCLUSIONS
  In patients with complex stone disease, adjuvant solution R irrigation can reduce the stone burden. There is a considerable potential for side effects necessitating close monitoring for sepsis and electrolyte abnormalities. However, the overall success rate for solution R is limited.
authors.affiliation: Bristol Urological Institute, Southmead Hospital, Bristol, UK.
authors.forename: H B
authors.initials: HB
authors.lastname: Joshi
authors.forename: P V
authors.initials: PV
authors.lastname: Kumar
authors.forename: A G
authors.initials: AG
authors.lastname: Timoney
mesh_terms: D000293:Adolescent; D000328:Adult; D002614:Chelating Agents / Q000009:adverse effects / Q000627:therapeutic use*; D019343:Citric Acid / Q000009:adverse effects / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000628:therapy*; D008096:Lithotripsy; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012189:Retrospective Studies; D007507:Therapeutic Irrigation / Q000009:adverse effects; D016896:Treatment Outcome
chemical_list: D002614:Chelating Agents; D019343:Citric Acid