Factors that predict spontaneous passage of a small distal ureteral stone <5 mm

We assessed the role of the unenhanced helical computed tomography (UHCT) for prediction of concurrent ureteral lesions associated with small impacted stones presenting in distal ureter.

From May 2004 to June 2009, we evaluated 30 cases with impacted distal ureteral stones <5 mm. All of the patients were evaluated with unenhancing UHCT, and the secondary signs on UHCT were graded on a scale of 0 to 3. All of the patients were treated by ureteroscopic pneumatic lithotripsy. Ureteral lesions associated with impacted stones were characterized on the basis of the ureteroscopic findings.

Ureteroscopic procedures showed that impacted distal ureteral stones <5 mm had concurrent ureteral lesions such as severe mucosal edema, strictures, ureteral polyps, or submucosal stones. Long-term stone impaction and the UHCT findings of a higher degree of the tissue rim sign, hydronephrosis, and perinephric fat stranding were associated with a higher likelihood of the presence of underlying ureteral lesions.

The secondary signs on UHCT such as high degree of tissue rim sign, hydronephrosis, and perinephric fat stranding seem to be useful signs in predicting the presence of concurrent ureteral lesions. In those cases, early intervention might have better outcomes than conservative therapy.