Results of urinary dissolution therapy for radiolucent calculi

Purpose: In this paper we present our experience with dissolution therapy of radiolucent calculi. Materials and Methods: This was a retrospective analysis of patients who were offered urinary dissolution therapy between January 2010 and June 2011. Patients were treated with tablets containing potassium citrate and magnesium oxide. Partial dissolution was defined as at least a 50% reduction in stone size. Patients with complete or partial dissolution were classified in the successful dissolution group. Patients with no change, inadequate reduction, increase in stone size and those unable to tolerate alkali therapy were classified as failures. Patient sex, stenting before alkalinization, stone size, urine pH at presentation and serum uric acid levels were analyzed using Fisher t-test for an association with successful dissolution. Results: Out of 67, 48 patients reported for follow up. 10 (15%) had complete dissolution and 13 (19%) had partial dissolution. Alkalinization was unsuccessful in achieving dissolution in 25 (37%). Stenting before alkalinization, patient weight (< 60 vs. > 75kg) and serum uric acid levels (<= 6 vs. > 6) were the only factors to significantly affected dissolution rates (p = 0.039, p 0.035, p 0.01 respectively). Conclusions: A policy of offering dissolution therapy to patients with radiolucent calculi had a successful outcome in 34% of patients.