[Efficacy of oral chemolysis in the management of staghorn uric acid nephrolithiasis]

Abstract

Staghorn nephrolithiasis represents one of the most complex forms of urolithiasis, with treatment approaches remaining a subject of ongoing debate among specialists. This study aims to assess the effectiveness and safety of oral chemolysis using citrate mixtures in treating staghorn urate nephrolithiasis. A prospective, multicenter cohort study was conducted from January 2023 to October 2024 among patients with CT-diagnosed staghorn stones of presumed urate composition (average urine pH less or equal 5.8, average stone density less or equal 650 HU, radiolucent on urogram or topogram) who received oral chemolysis with a citrate mixture containing citric acid, potassium bicarbonate, and sodium citrate ("Blemaren"). Patients were recruited from outpatient clinics and hospitals in Moscow. RESULTS: Of the 49 patients included in the study, 2 were excluded within the first 2 months. Complete stone dissolution was achieved in 30 patients (63.8%), while 17 patients (36.2%) eventually required surgical intervention. Among these, 4 patients (8.5%) achieved complete stone dissolution within 1 month of therapy, 18 patients (38%) within 3 months, and 8 patients (17%) within 6 months. Of the stones removed surgically, 12 (70.6%) were calcium oxalate, and 5 (29.4%) were uric acid stones. Consequently, the proportion of patients with non-calcium oxalate stones who did not achieve complete stone dissolution was 14.3%. Stone density was the only parameter that significantly influenced the likelihood of stone dissolution and the risk of surgical intervention (p<0.05). According to regression analysis, the likelihood of stone dissolution decreased by a factor of 1.012 with each unit increase in stone density, while the risk of surgery increased by a factor of 1.008 under the same conditions. CONCLUSIONS: The results of this study demonstrate that oral chemolysis for staghorn uric acid nephrolithiasis is an effective method and may serve as a viable alternative to surgical treatment, potentially reducing the associated risks of anesthesia and surgery for this patient group.

Keywords: citrate mixtures; oral chemolysis; staghorn uric acid stones; urolithiasis.