To describe a novel Small Fragment Removal System (SFRS) which is hypothesized to improve stone fragment removal during flexible ureteroscopy in patients with urolithiasis. The SFRS consists of three parts: a Syphon Ureteric Access Sheath (SUAS), a Dual Action Pump (DAP) and an Agitator. This bench assessment aims to assess the SFRS's impact on intra-renal pressure (IRP), irrigant flow rate and stone fragment removal compared to a traditional UAS.
A validated phantom kidney and fibre optic pressure sensor was used to assess IRP. Standardized irrigation via a flexible ureterorenoscope was instilled through a traditional UAS and compared to the novel SFRS. Both were 11/13Fr in size. Measured minute volume, IRP and percentage of stone fragments removed were compared.
The mean IRP using a traditional UAS and SFRS was 24,3mmHg and 9,4mmHg respectively. The flow rate of the traditional UAS was 25mL/min, compared to 31mL/min with the SFRS attached. During bolus fluid administration using the traditional UAS the maximum IRP increased to 41mmHg, compared to 9,3mmHg with the SFRS attached. A mean of 42,7% (0,103 g of 0,305 g) of weighed dry stones were removed with the traditional UAS compared to 77,6% (0,233 g of 0,299 g) with the SFRS attached, p = 0,017.
The described Small Fragment Removal System (SFRS) is different from traditional UASs by incorporating a syphoning mechanism. In addition, it has a Dual Action Pump which both boluses and augments the aspiration of irrigant by the Syphon. It further includes a deflectable Agitator to flush out stone fragments.
World journal of urology. 2024 Dec 06*** epublish ***
John Lazarus, Mark Wellman, Jørgen Wulfsberg, Tommaso Ceccato, Jeff John
Division of Urology, Groote Schuur Hospital, University of Cape Town, Cape Town, South Africa. ., Division of Urology, Groote Schuur Hospital, University of Cape Town, Cape Town, South Africa., Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway., Department of Surgery, Oncology, Gastroenterology and Urological Unit, University of Padova, Padova, Italy.