Urinary Calculi in Renal Transplant Recipients and in Renal Donors

Abstract

The incidence of renal lithiasis is increasing all over the world. It is a relative counter-indication to the kidney donation. Whenever a potential donor has a previous history of kidney lithiasis, the donation is allowed except upon the presence of metabolic disorder diagnosis, such as hypercalciuria, hyperuricosuria, hyperoxaluria, hypocitraturia or metabolic acidosis; cistine or struvite stones; urinary tract infection and multiple calculi or nephrocalcinosis. The calculi presented in kidney of deceased or living donors may spontaneously disappear, or they can be removed by ureteroscopy, percutaneous nephrolithotomy or extracorporeal shock wave lithotripsy. Renal lithiasis after kidney transplantation is not frequent, ranging from 0.2 to 3% (mean 1%), and it can occur either de novo or be recurrent. Patients are usually asymptomatic, since the transplanted kidney is denervated. The diagnosis occurs from 3 months to 3 years after transplant, but it is most frequently diagnosed during the first year. The calculi composition is quite different from the general population, being more frequent the uric acid stone and those associated to the urinary tract infection. Treatment depends on the size and location of the calculi and the experience of the transplantation center, and it includes extracorporeal shock wave lithotripsy, open or percutaneous nephrolithotomy, ureterorenoscopy, cistoscopy, and clinical observation (spontaneous passage).