Struvite and apatite urinary calculi

Struvite and apatite urinary calculi are crystalline mineral deposits that form within the urinary tract, primarily composed of magnesium ammonium phosphate and carbonate apatite (StatPearls, 2023). Often referred to as infection stones, their formation is fundamentally driven by the presence of urease-producing bacteria, such as Proteus mirabilis, which hydrolyze urea into ammonia and carbon dioxide (NIH, 2022). This enzymatic process increases urinary pH and provides the necessary ionic environment for the rapid precipitation of struvite and apatite crystals. These stones are clinically dangerous because they can grow into large staghorn calculi that fill the renal pelvis, leading to urinary obstruction, chronic kidney disease, and life-threatening sepsis (Mayo Clinic, 2023). While the stones themselves are the pathological outcome rather than a biological target, therapeutic interventions focus on inhibiting the bacterial urease enzyme with drugs like acetohydroxamic acid or dissolving the minerals using acidified irrigation solutions (FDA, 2020). Management typically requires a multi-modal approach involving surgical removal, targeted antibiotic therapy, and long-term metabolic monitoring to prevent recurrence.

Other names

Infection stonesTriple phosphate stonesStaghorn calculiMagnesium ammonium phosphate stonesCarbonate apatite stones

Urease inhibition to prevent mineral precipitation and chemical dissolution via acidification of the urinary environment.