Extracorporeal shock wave lithotripsy: Prematurely falling out of favour? A 7year retrospective study from an Australian high-volume centre.

Abstract

The aim of this study is to audit 7years of data with a 3year follow up from a high-volume stone centre performing extracorporeal shock wave lithotripsy (ESWL) to evaluate efficacy in stone clearance compared to existing knowledge and understand reasons for this performance. Patients who received ESWL treatment for renal or proximal ureteric stones at a single centre between January 2012 and January 2019 (to allow minimum 3year follow up) were retrieved. A retrospective analysis was performed cross referencing for stone size, location, treatment and need for further procedures. Ethical approval was granted through Metro North HHS HREC, Queensland, Australia. A total of 1930 patients met inclusion criteria. Fifty-seven percent (n = 1100) underwent left-sided ESWL, compared to 43% (n = 830) on the right. Stone size and location were both statistically significant to treatment outcome. Small stones (<1cm) had an overall clearance rate of 81.9%, medium stones (1-2cm) had a clearance rate of 60.6% and stones (>2cm) had a clearance rate of 31.3%. Small stones in an upper calyx had the highest clearance rate (87.5%, n = 120). Allowing for two procedures, 89% of stones were treated successfully. ESWL remains a legitimate option for the treatment of small and medium sized renal calculi. ESWL stone clearance rates at our centre are higher than published elsewhere and serve as proof to its efficacy. X-ray imaging on the day of the procedure, heavy consultant input and frequent intra-operative imaging are cited as key reasons for success. Further research is warranted to elucidate factors affecting stone clearance rate and to enable more standardised outcomes. Further investment may be required into ESWL provisions in most Australian states and especially in Queensland to enable its continued use in contrast to developing endourological techniques.