Comparing the effect of alpha-blocker versus observation on stone passage following shockwave lithotripsy treatment for renal or ureteric stones.

Extracorporeal shockwave lithotripsy (SWL) is a non-invasive method of treating kidney and ureteric stones <2cm in size. SWL uses high frequency sound waves to break stones into small fragments, to allow it to pass through the urinary tract. Tamsulosin is a selective alpha-1-adrenoceptor antagonist that may lead to ureteral relaxation, reduce pain associated with stone passage and enhance the passage of stone fragments. It has been reportedly used for this purpose for more than a decade. A recent scientific study (meta-analysis by Chen and co-authors) combining the result of multiple randomised controlled trials looking at the effect of tamsulosin in assisting stone passage has been published in 2015. The study of 2093 patients found tamsulosin to be effective in improving the passage of stones and reducing the pain associated with stone passage following SWL. When looking only at the subgroup of 442 patients with stone size of 4-10mm, the study did not find tamsulosin to be useful in assisting stone passage. This is consistent with a recent study by Pickard in The Lancet journal, which found tamsulosin to be not useful in assisting stone passage or reducing pain in patients with stones in the ureter. In Australian practice, SWL are generally used for stones less than 1cm in size. Therefore, at the moment there are still conflicting data on the usefulness of tamsulosin in the cohort of stone patients we treat in Australia with SWL. We aim to answer this question in our randomised trial. The meta-analysis by Chen in 2015 also recommended further study looking into the ability of tamsulosin to reduce repeated SWL and the economic benefits of tamsulosin in this setting. Therefore, we also aim to answer the question of whether tamsulosin use after SWL leads to any economic benefit, which can come from the reduced cost of medical service delivery, and reduced economic burden on the society.