THE EFFICACY OF EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY IN CALYCEAL CALCULI

Introduction: Treatment of patients with urinary calculi has undergone a dramatic change since the introduction of extracorporeal shock wave lithotripsy (ESWL) that proved to be highly effective with little morbidity. ESWL has become established as the preferred treatment for most upper urinary tract calculi. We assessed the efficacy of ESWL monotherapy for isolated lower pole nephrolithiasis and compare it to that for isolated middle and upper calyceal calculi. Materials and Methods: Patients with symptomatic urinary calculi who underwent ESWL as monotherapy were included in the study. Patients were evaluated with a plain film of the kidneys, ureters and bladder, excretory urography (IVP) and/or ultrasonography, urinalysis, urine culture, serum biochemistry and coagulation tests before the procedure. We treated 284 patients with isolated calyceal stones using a Stonelith V3 lithotripter (PCK, Turkey). The stones were localized in the lower, mid and upper calices in 155, 76 and 53 patients, respectively. The patients were further stratified into three groups based on stone diameter and included group 1- less than 1 cm., group 2- 1.1 to 2.0 cm. and group 3- greater than 2.0 cm. Results were classified as stone-free, clinically insignificant residual fragments, and failure. Clinically insignificant residual fragments were nonobstructive and non-infectious stone fragments and 4 mm. or less in size. Treatment was initiated with 9 kV, and energy was gradually increased by 0.5 kV to the maximum level (23 kV) that the patient could tolerate. The energy and shock waves, use of anaesthesia, number of treatment sessions, auxiliary measures and complications were noted. Results regarding calyceal localization were compared. Statistical analysis was performed by chi-square and Fisher's exact test. Results: The overall stone free rate was 59.35%, 76.3% and 77.35% for lower, middle and upper calyceal stones, respectively. There was no statistically significant difference between groups in mean age, number of treatment sessions, number of shock waves and stone diameters (p: 0.9, p: 0.5, p: 0.1, and p: 0.5, respectively). There was statistically significant difference between calyx groups and stone-free rate (p: 0.007). Stone-free rate in patients with lower calyceal stones was significantly lower than patients with middle and upper calyceal stones (p: 0.01, p: 0.02, respectively). The difference in stone-free rates among the middle and upper calyceal stones did not reach statistical significance. Steinstrasse developed in 20 (7.04%) patients in whom stones were localized in the lower, middle and upper calices in 10, 4 and 6, respectively. Temporary percutaneous nephrostomy tube placement for Steinstrasse was performed in 2 patients and double J catheter in 2 patients. Conclusion: ESWL appears to be successful for management of isolated calyceal stone disease. ESWL is effective, especially, in patients with upper and middle calyceal stones compared to lower calyceal stones.