PD15-02 THE EFFECT OF ALTERNATING BIDIRECTIONAL APPROACH DURING SHOCK WAVE LITHOTRIPSY FOR UPPER LUMBAR URETERIC STONES. A RANDOMIZED CONTROLLED TRIAL

Abstract

INTRODUCTION AND OBJECTIVE: to compare the outcome of shock wave lithotripsy (SWL) for upper lumbar ureteric stones using the alternating bidirectional approach versus the standard approach during the first session. METHODS: Our study was a randomized controlled trial (NCT03243682) including patients with single radio-opaque upper lumbar ureteric stone less than 1cm. SWL was conducted using electromagnetic Dornier Gemini Lithotripter. In group1, patients were treated with the alternating under and over-table approach during the first session only and if another one or more sessions were needed, the standard under-table approach was used. In group 2, patients were treated with the standard under-table approach during all sessions. The efficacy of stone disintegration after the first session was assessed by kidney-ureter-bladder (KUB) x-ray, renal ultrasonography (US). Noncontrast computed tomography was done for patients with no residual detected by KUB and US. Stone disintegration was classified as no (no change from basal by KUB X-ray or US imaging), partial (fragmented and >4-mm residual fragments), and complete (≤4-mm residual fragments). The incidence and severity of complications were evaluated. RESULTS: Forty eight patients in each group with comparable demographics and stone characteristics (table 1). Complete disintegration was achieved in 41.7% of patients in group 1 versus 18.8% in group 2 (p=0.021), while stone-free rate was 58.3% and 20.8% in group 1 and 2 respectively (p=0.001) (table 2). Stone length and width ≥8.5 mm and stone density ≥1135 HU significantly indicate disintegration failure in alternating bidirectional approach. CONCLUSIONS: For upper lumbar ureteric stones, stone disintegration and stone-free rate after the first SWL session are higher when using the alternating bidirectional approachSource of Funding: No