Clinical Research Directory

Comparison of Smart Pressure-Controlled Flexible Ureteroscopy and Flexible Suction Ureteral Access Sheath-Assisted Flexible Ureteroscopy for 2-3 cm Renal Stones

This prospective, multicenter, randomized, non-inferiority controlled trial aims to compare the efficacy and safety of smart pressure-controlled flexible ureteroscopy and flexible ureteroscopy assisted by a distal flexible suction ureteral access sheath in patients with 2-3 cm renal stones. Eligible patients will be randomly assigned to one of the two treatment groups. The primary objective is to determine whether smart pressure-controlled flexible ureteroscopy is non-inferior to the suction sheath-assisted approach in terms of stone-free rate. Secondary outcomes include operative time, postoperative complications, intrarenal pressure-related outcomes, length of hospital stay, and other relevant perioperative parameters. The findings are expected to provide clinical evidence to guide the selection of surgical techniques for patients with 2-3 cm renal stones.

Stone Clearance With Aspiration vs Other Technologies: a Real-world Evidence Study

The goal of this clinical trial is to evaluate the effectiveness and safety of Steerable Ureteroscopic Renal Evacuation (SURE) with the CVAC System versus other commonly used renal-stone interventions.

Combined Intravenous and Irrigation Tranexamic Acid During Percutaneous Nephrolithotomy

Percutaneous nephrolithotomy is a minimally invasive surgical procedure used to remove large kidney stones. Although it is an effective treatment, bleeding during and after the procedure remains one of the main concerns and may sometimes require blood transfusion. Tranexamic acid is a medication that helps reduce bleeding by limiting the breakdown of blood clots. It can be given through a vein and may also be used locally in irrigation fluid during surgery. This study evaluates whether using tranexamic acid by both routes during percutaneous nephrolithotomy can reduce blood loss, improve the clarity of the surgical field during endoscopy, and reduce the need for blood transfusion. The study included adult patients with kidney stones larger than two centimeters who were suitable for percutaneous nephrolithotomy. Patients were randomly assigned to receive either tranexamic acid through a vein and in the irrigation fluid, or normal saline as a control treatment. Blood loss was assessed using hemoglobin and hematocrit levels before and after surgery, as well as hemoglobin concentration in the irrigation fluid collected at the end of the operation. The surgeon also assessed the clarity of the surgical field using a ten-point visual scale. The hypothesis of the study is that combined intravenous and local administration of tranexamic acid in irrigation fluid during percutaneous nephrolithotomy reduces blood loss, improves surgical visibility, and lowers the need for blood transfusion compared with normal saline.

Phosphate & Kidney Stones

Kidney stones are common and often come back. One reason may be that some people with calcium stones have low phosphate levels in the blood and lose too much phosphate through the kidneys. They may also have high calcium in the urine, which raises the chance of forming stones. In older studies, high doses of phosphate supplements lowered urine calcium and appeared to reduce stone formation, but they sometimes caused stomach and bowel side effects, and phosphate is no longer used for stone prevention. This small pilot study will test a much lower dose of neutral phosphate (250 mg twice daily) for 2 weeks in adults with recurrent calcium oxalate kidney stones, high urine calcium, and low blood phosphate. Participants will collect a 24-hour urine sample and have blood drawn before and after the 2-week period. The study will look at whether the low dose reduces urine calcium and the risk of stone formation in urine. The results will help decide whether a larger study is warranted.

Trial of Ureteroscopy vs Steerable Continuous Flow Aspiration Technology

The goal of this clinical trial is to compare Steerable Ureteroscopic Renal Evacuation (SURE) using the CVAC System and standard ureteroscopy (URS) with laser lithotripsy for the treatment of urolithiasis. This is a prospective, randomized (1:1), multi-center study.

A Retrospective, Multi-center Real-world Study of Steerable Ureteroscopic Renal Evacuation (SURE) Procedure With the CVAC® System

This is a retrospective, multi-center collaboration to assess real-world outcomes of a novel steerable aspiration system, the CVAC® System ("CVAC"), and flexible and navigable suction ureteral access sheath (FANS) for the treatment of urinary stones.

Fecal Microbiota Transplantation in Kidney Stone Patients

This open-label pilot study evaluates whether oral microbial transplant therapy can change urine factors associated with recurrent calcium-oxalate kidney stones. Adults with high urine calcium or high urine oxalate will receive antibiotic pretreatment followed by microbial capsules. Changes in 24-hour urine calcium and oxalate and treatment safety will be assessed.

DISS vs FANS in Suction-Assisted RIRS for Medium-Sized Renal Stones

Kidney stones are a common health problem and may recur frequently, which can affect quality of life and kidney function. Retrograde intrarenal surgery (RIRS) is a minimally invasive treatment used for renal stones, but treatment of medium-sized stones may be associated with longer operative time, impaired visibility during surgery, residual stone fragments, and postoperative infectious complications caused by increased intrarenal pressure. Suction-assisted retrograde intrarenal surgery (RIRS) techniques have been developed to improve surgical efficiency and safety by facilitating continuous removal of stone fragments and helping control intrarenal pressure. Two commonly used suction-assisted approaches are direct in-scope suction (DISS) and flexible and navigable suction ureteric access sheath (FANS). However, there is limited prospective randomized evidence directly comparing these two techniques. This randomized prospective clinical study aims to compare direct in-scope suction (DISS) versus flexible and navigable suction ureteric access sheath (FANS) in adult patients with medium-sized renal stones measuring 1 to 2 cm who are undergoing retrograde intrarenal surgery (RIRS). Participants will be randomly assigned to one of the two suction-assisted techniques. The study will evaluate whether flexible and navigable suction ureteric access sheath (FANS) provides better outcomes than direct in-scope suction (DISS) in terms of stone-free rate and postoperative infection rate. The primary outcome is stone-free status assessed by postoperative imaging. Secondary outcomes include operative time, intraoperative visibility, and postoperative complications, particularly infection and urosepsis. The study hypothesis is that suction-assisted retrograde intrarenal surgery (RIRS) using the flexible and navigable suction ureteric access sheath (FANS) technique will result in a higher stone-free rate and a lower postoperative infection rate compared with direct in-scope suction (DISS) in the management of medium-sized renal stones.

FANS vs CVAC for Medium to Large Stones

Improvements in ureteroscopes have led to improved stone free rates. Two new devices (FANS - Flexible and Navigable Suction) and the CVAC ureteroscope have never been compared head to head. This trial will compare these two new suction ureteroscope technologies against each other

Empiric Versus Selective Prevention Strategies for Kidney Stone Disease

The aims of this study are to 1) Conduct a randomized clinical trial of selective versus empiric diet plus pharmacologic therapy in high-risk stone formers and 2) Determine adverse effects from, and adherence to selective and empiric strategies.

Evaluation of Eye Gaze Sharing in the Operating Room

This project aims to develop an augmented reality (AR) tool to enhance skill acquisition for endoscopic kidney stone surgery. Of the 100,000 patients who undergo an endoscopic kidney stone treatment annually in the United States, 25% will require a repeat stone surgery within 20 months of their index surgery. The repeat stone surgery rate is almost completely driven by postoperative residual stone fragments, which lead to ureteral obstruction, causing pain, urinary tract infection, and kidney injury. One significant factor that contributes to residual stone fragments is limited visualization of the entire collecting system - a skill directly associated with surgeon experience. This leads to novice surgeons having a much higher recurrence rate than experienced ones. As the incidence of kidney stone disease continues to increase (prevalence of 10%, incidence of 1116 per 100,000), improved endoscopic surgical training is required to improve outcomes of stone surgeries and minimize complications by improving stone-free rate. Currently, skill assessment during endoscopic stone surgery is limited. There are no objective metrics for endoscopic surgery to assess skill. The only feedback trainees get is in the form of verbal communication from expert surgeons, usually after the conclusion of surgery. Thus, most feedback is synoptic and limited in facilitating skill acquisition. Operative time and patient safety concerns restrict the amount of active, real-time feedback given during a case for skill acquisition. Endoscopic kidney stone surgery is uniquely challenging given the small depth and field of view of current endoscopes, which complicate the complete visualization of the entire collecting system. Navigation of the collecting system relies on mentally mapping preoperative imaging to the endoscopic surgical field. Success in mapping relies on hand-eye coordination, memory, and spatial reasoning, which are gained through practice. Thus, there is a need for tools that facilitate endoscopic surgical skill acquisition. The overarching hypothesis for this research is that surgical skill acquisition and outcomes for endoscopic kidney stone surgery can be improved by analyzing eye gaze data and using expert gaze to guide surgical trainees intraoperatively. Eye gaze guidance has been shown to lead to better skill acquisition in virtual reality surgical tasks compared with motion guidance alone. The proposed system would provide real-time education for trainees during endoscopic stone surgery, such as through head-mounted displays (i.e., the Microsoft HoloLens 2). The investigators have previously demonstrated eye gaze sharing in phantoms. By implementing this system in the operating room (OR), the investigators would be able to instill durable skill acquisition in trainees. The investigators will also implement the NASA-task load index for the trainees to gauge the usability of the system.

Pilot Study of Patient Navigation for Kidney Stone Patients After ED Visits

Patients who visit the emergency department for kidney stones are sometimes referred to urology for follow-up care but never complete that visit. Missing follow-up appointments can lead to worse outcomes, including recurrent pain, infection, or surgery. Research shows that patients who are socially or economically at risk (such as those with public insurance, lower income, or limited English proficiency) are more likely to experience these care gaps. This study will pilot a patient navigation program designed to help patients with urinary stone disease (USD) attend their scheduled urology appointments after being seen in the Emergency Department. Using an electronic health record (EHR) based prediction model developed in earlier research, patients at higher risk for being lost to follow-up will be identified and invited to participate. Each participant will be paired with a trained patient navigator who will assess barriers to care, provide support, and maintain contact for about 12 weeks. The goal of this study is to evaluate the outcomes and feasibility of this navigation intervention. Findings will help determine whether a larger study should test if this approach improves access to care and health outcomes for patients with kidney stones.

SGLT2i in Kidney Stones

This study is looking at whether empagliflozin, a medication typically used for diabetes and heart conditions, may affect factors that contribute to kidney stone formation. The research focuses on people who have had calcium-based kidney stones, i.e. calcium oxalate or calcium phosphate stones. Previous studies in those without kidney stones found that empagliflozin increased urinary citrate levels without raising urine pH. The investigators are testing whether similar effects occur in people with a history of kidney stones. Participants will take empagliflozin daily for 4 weeks. The investigators will collect 24-hour urine samples before and after treatment to measure various factors that influence stone formation, including citrate levels, pH, and calculated stone formation risk. The investigators will enroll 32 participants: 16 with a history of calcium oxalate stones and 16 with calcium phosphate stones. Results from this study may inform future larger clinical trials investigating empagliflozin as a kidney stone prevention strategy.

6.3Fr Versus 7.5Fr Mini-Flexible Ureteroscopy for Renal Stones (MINI-FURS)

This prospective, randomized, single-blinded, non-inferiority clinical trial will compare the clinical outcomes and cost-effectiveness of two mini-flexible ureteroscopes (6.3Fr and 7.5Fr) used during flexible ureteroscopy for the treatment of renal stones. Adult patients with renal stones up to 15 mm who are scheduled to undergo flexible ureteroscopy will be randomly assigned to one of the two study groups. The primary objectives are to compare stone-free rates and the ability to achieve primary renal access without preoperative ureteral stenting. Secondary outcomes include operative time, fluoroscopy use, ureteral trauma, postoperative stenting, pain, complications, emergency department visits, need for additional procedures, hospital stay, and cost-effectiveness. The results of this study are expected to provide high-quality evidence to guide the selection of mini-flexible ureteroscopes and improve the quality, safety, and value of surgical care for patients with kidney stones.

Endogenous Oxalate Synthesis in Idiopathic Calcium Oxalate Kidney Stone Disease

The goal of this clinical trial study is to test if patients with idiopathic calcium oxalate kidney stones have an increased production of oxalate by the body, which would lead to increased urinary excretion of oxalate. The study will recruit adult patients with a history of calcium oxalate kidney stones and healthy volunteers without kidney stones. Participants will ingest fixed diets containing low amounts of oxalate for 5 days ingest a soluble form of glycolate and vitamin C collect urine, blood, stool during the dietary and oral dosing portions of the study and also collect breath sample during the oral glycolate test

Comparing Efficiency and Stone-Free Rates Mini PCNL vs Flex URS

The objective of the study is to compare the stone free rates with ureteroscopy utilizing the ClearPETRA suction ureteral access sheath, and mini-PCNL; both procedures and ClearPETRA sheaths are standard of care and are used regularly for stone treatment. Our primary objective is to assess the complete stone free rate with both procedures.

Impact of Forced Diuresis on the Residual Fragment Rate After Flexible Ureteroscopy for Management of Renal Stones

This randomized controlled clinical trial evaluated whether furosemide-assisted forced diuresis during flexible ureteroscopy reduced the residual fragment rate and improved stone clearance in patients with renal stones measuring up to 30 millimeters. Adult patients undergoing flexible ureteroscopy were randomized into two parallel groups: an experimental group that received intravenous furosemide during the procedure and a control group that received standard perioperative and postoperative care without furosemide. Residual stone fragments were assessed using low-dose non-contrast computed tomography on postoperative day 1 and at 6 weeks after the procedure. The primary outcome was the proportion of patients with residual stone fragments greater than 2 millimeters on postoperative day 1. Secondary outcomes included the proportion of patients with residual stone fragments greater than 2 millimeters at 6 weeks, operative time, postoperative complications, and the need for auxiliary treatment for clinically significant residual stones.

CaOx Stone Prevention

This single-center randomized controlled trial at Mount Sinai West will enroll 80 patients undergoing percutaneous nephrolithotomy for calcium oxalate stones. Participants will be randomized to receive either empiric therapy or selective therapy guided by 24-hour urine evaluation. The primary outcome is change in calcium oxalate supersaturation at 4 weeks, aiming to determine whether empiric therapy can provide outcomes comparable to selective therapy while simplifying access to prevention.

Pain Control During ESWL Using Non-Opioid Analgesics

This prospective randomized controlled trial aims to compare the analgesic efficacy of three non-opioid analgesics (ibuprofen, paracetamol, and tenoxicam) during extracorporeal shock wave lithotripsy (ESWL). All patients undergoing ESWL will be randomly assigned into four groups including a placebo group. Pain intensity will be assessed using the Visual Analog Scale (VAS) at the 5th, 10th, 15th, and 20th minutes during the procedure. In addition to comparing analgesic efficacy, the study will evaluate patient-related and stone-related factors affecting pain perception, including body mass index, subcutaneous fat thickness, and stone density measured by Hounsfield Units. The study also aims to assess the relationship between analgesic efficacy, energy levels applied during ESWL, and treatment outcomes such as stone-free rates. The findings may contribute to optimizing individualized pain management strategies and improving treatment efficiency in ESWL procedures.

DISON I - Directly Integrated Suction and Optics System for the Treatment of Nephrolithiasis

A single-arm, multicenter, international, prospective interventional study designed to evaluate the safety and performance of an investigational device during retrograde intrarenal surgery for the treatment of renal calculi.

Ultrasound Imaging of Kidney Stones and Lithotripsy

The purpose of this study is to determine whether new software processing of ultrasound images can improve detection and size determination of kidney stones.

Comparison of Different Ventilation Modes for Reducing Kidney Motion During Retrograde Intrarenal Surgery

This randomized clinical trial will compare four ventilation strategies during retrograde intrarenal surgery performed under general anesthesia. The study aims to determine whether reducing respiratory-related kidney movement improves surgical success and decreases perioperative complications. Eighty adult patients will be randomly assigned to standard ventilation, hypoventilation, intermittent apnea ventilation, or one-lung ventilation. Surgical outcomes and perioperative complications will be compared between groups.

Modified Mini-PCNL Versus Standard PCNL for Complex Kidney Stones

Kidney stones that are large or complex are often treated with percutaneous nephrolithotomy, also called PCNL. Standard PCNL uses a larger access tract and is effective for removing complex kidney stones, but it may be associated with more bleeding, pain, and recovery burden. Modified mini-PCNL uses a smaller access tract and may reduce surgical trauma while maintaining a similar stone clearance rate. This multicenter randomized trial will compare modified mini-PCNL using a 20 Fr access sheath with standard PCNL using a 24 Fr access sheath in adults with complex renal stones. About 1,380 participants from 8 urology centers will be randomly assigned to receive one of the two procedures. The main purpose of the study is to determine whether modified mini-PCNL is not worse than standard PCNL in achieving stone-free status shortly after surgery. Stone-free status will be assessed by low-dose noncontrast CT within 72 hours after surgery. The study will also compare stone-free status at 3 months, complications, operation time, length of hospital stay, need for additional procedures, and quality of life.

Thulium Fiber Laser (TFL) vs Thulio Pulsed Thulium:YAG (p-Tm:YAG)

This research study is being conducted to assess the ability and efficiency of two laser systems to break up kidney stones during ureteroscopy with laser lithotripsy for kidney stone treatment.