Antenatally detected, unilateral dilatation of the renal pelvis: a critical review. 1. Postnatal non-operative treatment 20 years on--is it safe?

BACKGROUND

Non-operative postnatal treatment of antenatally detected hydronephrosis, consistent with pyelo-ureteral obstruction, has functioned well during follow-ups of up to 17 years. However, doubts are still expressed and, admittedly, the final verdict on this new policy is still remote. The purpose of this review is to define the state of art and to serve as a background for future randomized clinical trials, which still are missing.

METHODS AND MATERIAL: From the literature, 6 patient series were chosen based on the following criteria: publication during the 1990s to allow for a longer follow-up and better diagnostic tools; consecutive patient series; and compliance with a 50-point form. Data, from 593 kidneys, were then pooled. Result of the compilation: Four hundred and seventy-four kidneys, with differential function >40%, were allocated to expectancy and followed for 2-144 (mean 23) months. Four hundred and twenty-five (90%) were successful, independent of presence of caliectasis. Forty-nine (10%) had delayed pyeloplasty, after which declined function mostly improved / normalized - similar to 108 kidneys with early pyeloplasty because of an initial differential function <40%. Hydronephrotic size and isotope wash out rate did not predict outcome.

CONCLUSIONS

These figures agree with other reports: few cross-overs and functional recovery also after delayed operations. Thus, so far, with a caveat for future deterioration, expectancy seems safe and promising, in unilateral and probably in bilateral cases with normal function, although perhaps not in solitary kidneys. Hopefully, this review, together with a forthcoming communication on long-term risks and urgent research needs, will help to design future randomized clinical trials.