Lithotripsy, Laser

The use of FANS has changed the operative landscape of RIRS by allowing continuous active suction-assisted clearance of ablated stone material in real time. Use of fragmentation technique in FANS requires high-energy to reduce stone burden into small fragments, followed by active suction of residual fine material. Dusting with FANS, on the other hand, converts the entire stone volume into sub-millimetre particulate that is continuously suctioned away during lasing potentially offering a more streamlined workflow with potentially less energy usage, reduced mechanical stress on the ureteroscope working channel, and fewer scope withdrawals. The combination of TFL dusting with FANS-assisted real-time evacuation may produce stone-free outcomes equivalent or superior to fragmentation, while offering these additional operative efficiencies. Whether dusting using TFL with FANS is non-inferior or indeed superior to fragmentation using TFL with FANS in terms of stone-free rate at one month has not been evaluated in prospective randomised trial yet. This study aims to answer that specific question in patients with renal stone less than 2 cm.

The incidence of kidney stones (urolithiasis) has surged in both developing and developed countries, affecting approximately 15% of the global population. From 2010 to 2019, diagnoses of kidney and ureteral stones rose by 8% in Germany, 26% in France, and 15% in England. Correspondingly, the number of surgical stone removal procedures increased by 3%, 38%, and 18%, respectively. Common treatments include extracorporeal shock wave lithotripsy (ESWL), ureterorenoscopy (URS) with lithotripsy, and percutaneous nephrolithotomy (PCNL). URS, depending on stone size, has become a preferred method due to advancements in intraoperative imaging and laser technology. Despite these improvements, small fragments often remain post-intervention, leading to recurrent stones. Complete removal of all fragments is crucial to significantly reduce recurrence rates. Current literature suggests a high recurrence rate with residual fragments, impacting healthcare costs and patient quality of life. A key objective in endourological research is optimizing the stone clearance rate. Techniques like coagulum lithotomy and the autologous blood clot technique have been developed to enhance residual stone removal after laser fragmentation. These methods benefit selected patients but are not widely adopted due to complications such as reduced intraoperative visibility and long coagulum formation times. Recently, a two-component hydrogel system called mediNiK® (Purenum GmbH, Germany) was developed. This biocompatible gel can be applied through an endoscope after stone fragmentation and large fragment retrieval to embed smaller fragments and dust, forming a removable conglomerate. MediNiK® has demonstrated effectiveness in embedding and removing stone residues and is already in clinical use in Europe, showing potential for optimizing stone removal. A multicenter study has assessed the safety and tolerability of mediNiK® in standard URS (Open, randomized, multicentre study to evaluate the safety, tolerability, and performance of mediNiK® compared to standard treatment in kidney stone removal - DRKS00030532). Results indicate the gel is safe and tolerable. However, further data from larger cohorts and comparisons with conventional URS are necessary before widespread adoption of mediNiK®.