Is intravenous urography a prerequisite for renal shockwave lithotripsy?

PURPOSE

To determine whether intravenous urography (IVU) is a prerequisite for shockwave lithotripsy (SWL) of renal stones by addressing whether using non-contrast-enhanced CT (NCCT) instead of IVU for delineating urinary tract anatomy is associated with post-SWL complications.

PATIENTS AND METHODS

Thirty-eight patients treated by SWL (Econolith 2000) for radiopaque renal stones underwent either IVU or NCCT. Twenty patients with normal urinary tracts or with mild hydronephrosis proximal to the stone on urography comprised the IVU group. Eighteen patients who underwent NCCT and plain abdominal (KUB) films and had urinary tract systems similar in appearance to the IVU group comprised the NCCT group. The two groups were of similar mean age (45.75 years, range 24-73 years; and 49.0 years, range 26-72 years, respectively) and had a similar mean stone size (10.1-10.2 mm). Patients with internal ureteral or nephrostomy catheters were excluded. Information on episodes of intractable renal colic, urinary tract infections, and hospitalization was recorded at follow-up 2 to 6 weeks post-SWL.

RESULTS

The IVU and NCCT patients had similar mean stone fragmentation rates (80% and 74%, respectively) at 2 to 6 weeks post-SWL. Four IVU patients (20%) had intractable renal colic. One NCCT patient (5.5%) had a urinary infection. Complication and hospitalization rates in the two groups were not significantly different (P = 0.34; Fisher' exact test).

CONCLUSIONS

Using only NCCT before SWL was not associated with higher complication rates. Thus, IVU is not a prerequisite for SWL of radiopaque renal stones in patients with a normal urinary tract anatomy as seen on NCCT.