Do you recommend 24 hour urine stone risk studies for patients with no history of nephrolithiasis who are undergoing evaluation as potential kidney donors?

We ask all donors if they have had a history of kidney stones. All donors also get a CT angiogram of the abdomen. Patients with a stone history will need a 24-hour urine stone risk profile. If a donor has an incidental single stone, we may still allow donation, but we would ask for a 24 stone profile as well. In patients with neither of these findings, a 24-hour urine stone risk study is not required at our center.

No. 24-hour urine studies typically calculate the risk of making stones from the concentration of urinary minerals. They typically do not take into account the naturally occurring inhibitors of stone formation. Thus, a “positive“ 24-hour urine supersaturation study in a never-stone former is not very predictive of future stones.

Although passing a kidney stone in a denervated transplanted kidney is painless, the potential for obstruction and infection is definitely there. Still, I think the bene...

We do a 24 hour urine for stone risk for potential donors who have either a history of stones (not your question), h/o hyperparathyroidism, history of bariatric surgery (roux-en-Y is typically a rule out), or family history of stones. For family history, if the potential donor is < 40 yo with one first degree family member with a stone, or >40yo with two or more first degree family members with stones the we do a 24 hour urine study.