An interventional study of flexible and navigable ureteral access sheath and conventional ureteral access sheath in Urolithiasis, sponsored by Namik Kemal University. Recruiting at 1 site in Turkey (Türkiye). Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-07-06.
Sponsored by Namik Kemal University · Not applicable, Interventional, and Screening
Kidney stone disease is a common condition, and retrograde intrarenal surgery (RIRS) is a minimally invasive procedure frequently used to remove kidney stones. During RIRS, pressure inside the kidney can increase, which may contribute to temporary kidney injury. New aspiration-enabled access sheath systems have been developed to better control this pressure by continuously removing irrigation fluid during surgery. This study will compare aspiration and conventional access sheath systems to determine whether improved pressure control reduces early kidney injury. Blood and urine biomarkers (IL-18 and L-FABP), which can detect kidney damage earlier than standard kidney function tests, will be measured before and after surgery. The results may help identify surgical techniques that better protect kidney function and improve the safety of kidney stone treatment for patients.
Urinary system stone disease is a common condition in urological practice, and with advances in minimally invasive surgical techniques, retrograde intrarenal surgery (RIRS) has become a widely preferred method, particularly for treating small and medium-sized kidney stones, owing to its high stone-free rates and low morbidity. The ureteral access sheath (UAS), routinely used during RIRS, offers advantages such as facilitating repeated entry and exit, shortening operation time, optimizing irrigation flow, and reducing intrarenal pressure. However, controlling intrarenal pressure is critical not only for surgical comfort but also for renal physiology and patient safety. Increased intrarenal pressure can lead to pyelovenous, pyelolymphatic, and pyelotubular regurgitation, increasing the risk of bacterial translocation, sepsis, and renal parenchymal damage. In particular, the damage that high intrarenal pressure can cause to the renal parenchyma and the resulting acute kidney injury (AKI) are of significant importance in critically ill patients who are clinically at risk of renal failure. Recent developments of aspiration-enabled intrarenal electroconvulsive (IOC) systems aim to more effectively and continuously control intrarenal pressure by providing active fluid drainage. Theoretical advantages of these systems include lower intrarenal pressure levels, improved visualization quality, and potentially lower complication rates. However, the effects of these systems on renal function have been evaluated in a limited number of studies in the current literature, and their effects, particularly on subclinical renal damage, have not been clearly established.
Acute renal injury (AKI) is a rare but clinically significant complication following RIRS, and it is often undetectable early using conventional biochemical parameters (e.g., serum creatinine). Therefore, the use of early and sensitive biomarkers is becoming increasingly important. In this context, Interleukin-18 and Liver-type fatty acid binding protein (L-FABP) stand out as promising biomarkers that can reflect early renal tubular damage and predict the development of AKI. The aim of this study is to comparatively evaluate the effects of aspiration and non-aspiration ureteral access sheath systems used during RIRS on postoperative acute renal injury, based on changes in IL-18 and L-FABP levels. Furthermore, by revealing the relationship between intrarenal pressure control and biochemical injury markers, the study aims to provide stronger evidence for the potential clinical benefits of aspiration systems.
253 studies on the registry are indexed under Urolithiasis; 67 are open to participants now.
This study's planned enrollment of 108 is close to the median of 100 across 182 interventional studies indexed under Urolithiasis.
Browse Urolithiasis studies →Namik Kemal University is the lead sponsor of 61 studies on the registry; 17 are open to participants now.
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Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Device: flexible and navigable ureteral access sheath
Device: conventional ureteral access sheath
Patients of RIRS operated with flexible and navigable ureteral access sheath
Patients of RIRS operated with conventional ureteral access sheath
acute kidney injury
Serum IL-18 and L-FABP levels at the stated timelines.
Time frame: preoperative, postoperative 24th hour and postoperative 7. days
Plan to share: Yes
Supporting information: Study protocol
Started May 2026 (actual). Primary completion is estimated for Jun 2027, 13 months after the start.
Of 86 non-industry interventional studies with no phase under Urolithiasis, half reached primary completion within 20 months of starting (the median), counting those still running; a quarter within 11 and three quarters within 40. This study's planned 13 months is below that.
Counting every sponsor, half of 96 studies reached it within 19 months; a quarter within 11 and three quarters within 39.
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