Comparative results of shockwave lithotripsy for renal calculi in upper, middle, and lower calices

To assess the results of shockwave lithotripsy (SWL) for renal calculi in upper, middle, and lower calices according to the stone burden.

A series of 52 female and 66 male patients with a mean age of 47.8 years and isolated single caliceal stones who underwent SWL monotherapy were enrolled. Stone burden, stone location, number of sessions/shockwaves, and auxiliary procedures were noted for each patient. Stones were located in the upper, middle, and lower calices of 35, 43, and 40, patients respectively, with mean stone burdens of 81.4 mm2, 75.2 mm2, and 96.3 mm2, respectively. Patients were evaluated with intravenous urography, plain film, or ultrasonography. Success was determined 3 months after the last session. Re-treatment rates were calculated. The effect of anatomic factors on the success of treatment for lower-caliceal stones also was determined.

The mean stone burden, median number of treatment sessions, and mean number of shockwaves were 84.2 mm2, 2, and 4344, respectively. The auxiliary procedure rate was 16.1%, and the re-treatment rate was 71.2%. Failure was noted in 26 patients (22%). The stone-free rates for stones in the upper, middle, and lower calices were 82.8%, 83.4%, and 67.5%, respectively (P = 0.14). The stone-free rates for stones <100 mm2 and 100 to 200 mm2 were 91.2% and 65.5%, respectively (P = 0.001). The efficiency quotient was 49.8, 44.8, and 32.5 for upper-, middle-, and lower-caliceal stones, respectively. Infundibular length (P = 0.006) and infundibular width (P + 0.036) were significant in determining the stone-free rate after treatment of lower-caliceal stones.

We recommend SWL as the first choice for treatment of stones <200 mm2 in the upper and middle calices. Extracorporeal lithotripsy is one of the options for lower-caliceal stones <200 mm2 but has high re-treatment and auxiliary-procedure rates in these cases.