Outcome and safety of extracorporeal shock wave lithotripsy as first-line therapy of lower pole nephrolithiasis

INTRODUCTION: The aim of this study is to assess the efficiency of extracorporeal shock wave lithotripsy (ESWL) as initial therapy for isolated lower pole kidney stones smaller than 20 mm. PATIENTS AND METHODS: During a 24-month period 116 patients with previously untreated single stones under 20 mm in diameter were treated with a Dornier lithotripter S. They were analyzed with regard to stone site and size, number of ESWL sessions, auxiliary measures, retreatment rates, complications and the time taken for stone clearance. RESULTS: 76 patients (65.5%) became stone free, 50 of them (43.1%) within 3 months after ESWL. Depending on stone size the stone-free rates were 67.1% for patients with a stone diameter of <10 mm (59 of 88 patients), and 60.7% for stone diameters between 10 and 20 mm (17 of 28 patients). Complications during and after treatment were rare, i.e. the necessity of ureteral stent insertion due to colic (n = 10), endoscopic stone removal (n = 2), acute pyelonephritis (n = 1), stonestreet (n = 1) and 1 case of hematoma not requiring intervention. The recurrence rate during follow-up (13.2-36.9, mean 25.0 months) was low: 16 patients (13.8%) had recurrent or persistent stones, and 74 patients (63.8%) had no evidence of urolithiasis. CONCLUSIONS: ESWL is a safe and efficient first-line therapy for treatment of isolated small lower pole kidney stones with acceptable stone-free rates, low morbidity, few complications and a low stone recurrence rate.