Ultrasonographic evaluation of ureteral stones in children: can we use stone width as a predictor of spontaneous passage?

Aims: We aimed to obtain the maximum transverse diameters (widths) of ultrasonographically detectable ureteral stones in children and to evaluate the effect of widths on the rate of spontaneous discharge and on the degree of ipsilateral hydronephrosis.

Material And Methods: We retrospectively evaluated 52 ultrasonographically detected ureteral stones in 51 consecutive patients (32 males, 19 females) with a median age of 9 years (range, 6 months-17 years).

Results: In group 1, in which the stones passed spontaneously (n=29), sonographically measured median and mean widths of ureteral stones were 3.8 mm (range, 2.3-7.3 mm) and 4.1+/-1.3 mm, respectively. In group 2, in which the stones required surgical procedures (n=23), median and mean widths were 5.9 mm (range, 3.9-10.0 mm) and 5.9+/-1.8 mm, respectively. The difference between widths in group 1 and group 2 was significant (p=0.001). With regard to the whole study group (n=52), the majority of the stones below 4.0 mm (88.9%, n=16/18) were passed spontaneously and 2/3 of the stones above 5.0 mm required intervention (66.7%, n=12/18). The width range of 4.0-5.0 mm can be accepted as "range of transition" for spontaneous passage and surgical procedures. The stone width was different in patients with mild and severe pelvicaliectasis (p=0.0001).

Conclusions: In children, measuring the width of an ultrasonographically detectable ureteral stone can be useful for assessing its possibility to be passed spontaneously. Pelvicaliectasis should be an alerting sign for the presence of an occult ipsilateral ureteral stone in a symptomatic patient.