[Calcification and contamination as complications in the use of double-J catheters: incidence and correlation].

We present a series of cases of complex renal lithiasis, in which we carried out temporary internal urinary bypassing, prior to extracorporeal lithotripsy, by means of the retrograde insertion of a double-J urethral catheter, studying the time of stay, the presence or not of contamination in the catheter and its relationship with the calcifications found in them. We also carried out a metabolic-functional study of each patient, determining the urinary pH and the serum and urinary calcium, phosphorous and uric acid concentrations, and observing their possible influence on the above-mentioned complications. Of the 25 catheters studied, we observed calcification in 11 cases (44%). In these we observed urealytic germs (Proteus and Pseudomonas), without finding modifications of urinary pH. We observed no relationship between the calcium deposits and serum and urinary calcium, phosphorous and uric acid concentration.