Alkaline citrate reduces stone recurrence and regrowth after shockwave lithotripsy and percutaneous nephrolithotomy

TLDR: Sodium-potassium citrate provides positive effects on stone-forming activities in calcium stone patients suffering from urolithiasis following treatment with ESWL and PCNL procedures at the 12-month follow-up.

Abstract: Expert’s summary: This study is a randomized comparison of patients with residual stone material in the kidney after shockwave lithotripsy (SWL) and percutaneous nephrolithotomy (PNL) who were treated with alkaline citrate (ALK) or left untreated. After a relatively short follow-up period (12 mo), there were significant differences in terms of stone-free kidneys, regrowth of residuals, and new stone formation. Of initially stone-free patients treated with ALK, 7.7% had formed new stones after 1 yr compared with 42.3% of those without such treatment. In patients with residual fragments, more patients in the ALKtreated group became stone free, and growth of residual fragments was encountered in 7.7% of the treated group and 54.5% of the control group. The conclusion from this study was that treatment with ALK gives positive effects in patients both with and without residual fragments after active stone removal. Expert’s comments: Although it has been shown previously that ALK is efficient in counteracting new calcium stone formation [1] as well as regrowth of residual fragments [2,3], this article is a valuable reminder of the usefulness of medical treatment of patients with calcium stone disease. At a time when there has been a considerable technical development of ureteroscopes and stone-disintegrating devices, the enthusiasm to use these instruments has placed recurrence prevention in the shadows, and this field is seriously neglected today. It is recognized that asymptomatic residual fragments might be present in the kidney after SWL; however, it needs to be emphasized that residual fragments are also common after retrograde intrarenal surgery and occur even after PNL. Moreover, it is also notable that in cases of obviously complete clearance of calcium stones, recurrent stone formation is considerable, with an average risk of new stone formation in as many as 5% after 1 yr and 30% after 5 yr. In the reported study, sodium potassium citrate was used as the only agent, and it is possible that this form of treatment was particularly useful for fragment clearance [4]; however, I personally am in favor of a selective recurrence prevention based on biochemical findings. The sodium content might result in increased excretion of calcium that is not entirely positive, and the follow-up period is too short for general conclusions. The message of this report, however, is clear: Considering use of medical agents to facilitate fragment passage and to counteract new stone formation and growth of residual fragments should be part of the urologic care of patients with calcium stone disease. This is particularly important for those patients who have a previous history of stone formation and for those who have asymptomatic residual fragments. Both of these groups also should have an individualized follow-up program [5].