A Direct Comparison of the Litholytic Capacity of Renacidin and Some New Calcium Oxalate and/or Phosphate Dissolving Irrigation Systems

There are two possible systems for chemolitholysis, oral (systemic) and local (instrumental). Oral dissolution of urinary stones is successful only for uric acid calculi. Local chemolitholysis may be used for urate, cystine and phosphate, especially struvite, calculi. But, oxalate concrements cannot be dissolved by this means. Our approach to oral chemolitholysis, especially of “young” phosphate calculi, is based on increasing the Cabinding capacity of urine by the stimulation of the tubular secretion of citrate. This is achieved by the reversible, competitive inhibition of tubular intramitochondrial citrateoxidizing enzymes or by the renal elimination of compounds which complex urinary Ca2+. In instrumental chemolitholysis our experiments have focused on new irrigation solutions that may be capable of dissolving, not only struvite, but also calcium oxalate and apatite calculi. From direct comparisons of litholytic rates, the practicability of calcium oxalate dissolution by irrigation in stone-patients as well as the average expected treatment-time may be predicted. Struvite calculi are known to be dissolved by hemiacidrin on an average within 10 days1−4. By alternation of calcium- and oxalate-binding irrigation systems, calcium oxalate calculi could be dissolved at the same dissolution rate as struvite concrements treated with hemiacidrin.