ABSTRACT
Archaeological records from ancient Egypt, Babylonia, and China show that infection stones have afflicted humans for millennia. In the early 19th century, the chemical composition of infection stones was elucidated as Magnesium Ammonium Phosphate (MgNH4PO4·6H2O). They are also called struvite (named after the Russian naturalist, Baron von Struve), infection-induced, phosphatic and triple phosphate stones in the medical literature. Struvite calculi often coexist with calcium carbonate apatite crystals (Ca10(PO4)6·CO3) due to their shared propensity for forming in alkaline urine. Struvite/Calcium carbonate apatite crystals in the urinary tract commonly aggregate and grow to form large, branched stones called staghorns. Indeed, they account for approximately 75% of staghorns, whereas uric acid, cystine, and calcium oxalate or phosphate calculi account for the remaining 25%.(1) Although struvite calculi represent less than 10% of urolithiasis cases in North America, their potential for morbidity and mortality make them important for physicians to recognize and treat expeditiously.(2)
Firstly, untreated infection stones are capable of rapidly growing to fill all the calyces in the kidney (staghorn) and causing progressive renal demise. This was illustrated by a study that analyzed 1,391 consecutive patients started on hemodialysis between 1989 and 2000 at the Necker Hospital in Paris.(3) 3.2% of the patients required hemodialysis as a result of chronic nephrolithiasis, with a disproportionate number (42%) occurring in patients with a history of recurrent struvite calculi.
