Unsuspected urological anomalies in asymptomatic cryptorchid boys

In a period of 6 years 144 asymptomatic boys with cryptorchidism, of mean age 7 +/- SD 3.5 years, underwent orchiopexy. None of these boys referred to a history of a known urological anomaly, urinary tract infection, haematuria, palpable mass in the renal region, bladder extrophy, epispadias, hypospadias or anorectal malformation. On the third day after orchiopexy and intravenous pyelography was done in every boy following testicular protection against irradiation. Ultrasonic investigation was not available at that time. There were minor urological abnormalities in 36 (25%) boys and major ones in 8 (5.5%) boys. A major anomaly is defined as one resulting in significant loss of renal substance (one case of single kidney and three cases of unilateral renal hypoplasia), or requiring surgical correction for conservation of the renal substance (one case of ureterocele, two cases of pelviureteric stenosis and one case of vesicoureteric stenosis with ipsilateral hydronephrosis). The unsuspected major urological abnormalities are usually ipsilateral to the more undescended testis. They may be associated with a hernia and are more frequent in bilateral cryptorchidism. In conclusion we encourage the routine use of IVP, or ultrasonic investigation or dynamic renal scanning (99mTc-DTPA), if it is possible, in all patients undergoing orchiopexy for the detection of an unsuspected major renal anomaly.