Thread by @diesantillan

📚 Based on Urology by Campbell

#uroquiz #endourology #urosome

@MSGONZALEZURO @ResidentesAEU @sbinhamrii @oangerri @Urologeman @CheatUrology @drkemalsarica @FCFigueiredo @migokce

🚩The most significant factor for #stone formation in pts w/ #struvite calculi is:

✅ ℝ𝕖𝕔𝕦𝕣𝕣𝕖𝕟𝕥 𝕌𝕋𝕀𝕤

🔹Struvite stone formation typically occurs in pts w/ recurrent UTI and retained urine

🔹Predisposing factors include:
🔸urinary tract obstruction
🔸chronic indwelling catheter
🔸urinary diversion
🔸neurogenic voiding dysfn

📸 @VelezNephHepato

🔹Most commonly, #staghorn stones are composed of a mixture of struvite (magnesium ammonium phosphate) and calcium carbonate apatite.

🔹#Struvite calculi are typically referred to as “infection stones” because of their strong association w/ UTI.

📸 Radiopaedia.org

🔹#Urease producers include:

🔸PROTEUS MIRABILIS (75%)
🔸Klebsiella
🔸Pseudomonas
🔸Staphylococcus

🔸Escherichia coli, only rarely produces urease and thus is an infrequent cause of staghorn calculi.

📸 Cristian Follmer

🔹#Urease produced by such bacteria leads to hydrolysis of urea to ammonium, hydroxide, and bicarbonate, which ⬆️ the pH of the urine (pH >7.2).

This alkaline urine, in the presence of trivalent phosphate, results in struvite crystal formation!