Clinical Research Directory

Methocarbamol vs Oxybutynin for Management of Pain and Discomfort S/P Ureteroscopy Procedure

Stone disease is a common condition, affecting approximately 9% of Americans in 2007. It causes great morbidity and is also a costly condition, estimated to cost the US healthcare system approximately 3.79 billion dollars in 2007. Ureteroscopy (URS) is the most commonly performed surgical treatment for upper tract stone disease. Ureteral stenting is a common practice after ureteroscopy and placed in \~75% of cases to prevent ureteral edema and renal obstruction. Unfortunately, ureteral stenting can be very painful and has been shown to increase the rate of emergency room visits. Many strategies have been attempted to decrease pain with ureteral stenting including modification of stent material and designs, but efforts so far have been unsuccessful in decreasing stent-related morbidity. Stent-related morbidity is hypothesized to be secondary to irritation of ureteral/bladder mucosa and muscle. Analgesics such as alpha blockers and NSAIDs have been shown to reduce stent morbidity. Anticholinergic drugs are also utilized as they decrease bladder spasms and, therefore, are hypothesized to reduce stent irritation. However, the evidence for anticholinergics has been conflicting. Anticholinergics also have a serious side effect profile including dry mouth, dry eyes, constipation, urinary retention, blurred vision, and even dementia. Some authors even hypothesize that these side effects may offset any purported benefits the anticholinergics provide for stent-morbidity. Methocarbamol is anti-spasmodic muscle relaxant that is believed to work by acting on central neurons and possibly by blocking sodium channels. Given that anticholinergics have many side effects and questionable efficacy, the investigators hypothesize that methocarbamol may achieve superior analgesia for stent morbidity and stent-related bladder spasms. Oxybutynin is used for the treatment of overactive bladder. The rationale is that the oxybutynin relaxes the muscles in the bladder to help decrease problems of urgency and frequent urination caused by the urinary stent irritation. Since anticholinergics have multiple side effects, finding an equally efficacious alternative with less side effects is highly desirable. This study will evaluate the clinical and demographic factors of patients undergoing ureteroscopy and treated postoperatively with methocarbamol vs. oxybutynin for stent-related morbidity. Additionally, the study will aim to understand the postoperative outcomes and complication rates of patients discharged with methocarbamol vs. oxybutynin after ureteroscopy with a ureteral stent in place.

Human Voice vs AI-Cloned Voice Audio Added to Written Consent Before Ureteroscopy or Retrograde Intrarenal Surgery (AUDIO-CONSENT)

Before kidney stone surgery with a flexible or semirigid ureteroscope, patients must read and sign a written consent form, but many patients find these forms long and hard to understand. This study tests whether listening to an audio recording of the same consent form, in addition to the usual written form and the surgeon's explanation, helps patients understand the operation better. It also asks whether it matters if the recording is read by a real urologist or produced by artificial intelligence (AI) from a clone of that same urologist's voice. Adults scheduled for their first ureteroscopy or retrograde intrarenal surgery at three hospitals in Turkey will be randomly assigned to one of three groups: (A) standard written consent only, (B) standard consent plus an audio recording read by a urologist, or (C) standard consent plus the same text produced by an AI-cloned version of the same urologist's voice. All three groups receive exactly the same information, word for word; only the way it is delivered differs. Patients in group C are told that the voice was produced by AI. The main outcome is a 10-question knowledge test on the content of the consent form, taken immediately after the consent process. Anxiety (State-Trait Anxiety Inventory) and satisfaction are also measured on the same day. No forms are completed on the day of surgery.

Risk Factors and Predictive Model for Inflammatory Polyps in Ureteral Stones

This is an observational studyincluding an internal retrospectivedevelopment cohort, an internalprospective temporal validation cohortand two external validation cohorts fromtwo independent external centers. Thestudy aims to identify independent riskfactors for inflammatory ureteral polypsin patients with ureteral calculi anddevelop a preoperative predictive model Retrospective clinical and radiologicaldata were extracted from eligiblepatients treated from January 1, 2018to December 31, 2025 (n=874). Theprospective cohort consecutivelyenrolled participants from April 72026, to September 7, 2026 (n=162)Consecutive eligible patients from twoexternal centers were included forexternal validation (n=139 and n=176).The primary outcome is theintraoperative diagnosis of inflammatoryureteral polyps

Comparison of Mirabegron and Tamsulosin for Ureteral Stone Expulsion

This randomized controlled trial compares the efficacy and safety of four treatment strategies for ureteral stone expulsion: Mirabegron alone, Tamsulosin alone, a combination of both, and standard conservative care. Participants diagnosed with ureteral stones will be randomly assigned to one of these four groups. The primary objective is to evaluate the stone expulsion rate within 4 weeks. The study also assesses time to expulsion, pain intensity, analgesic use, and potential side effects.

Extracorporeal Shock Wave Lithotripsy Versus Ureteroscopy for Upper Ureteric Stones

Upper ureteric stones can be treated using extracorporeal shock wave lithotripsy or ureteroscopy. Extracorporeal shock wave lithotripsy breaks the stone using shock waves delivered from outside the body, whereas ureteroscopy involves passing a small instrument through the urinary tract to locate and fragment the stone. This randomized controlled trial compared the effectiveness and safety of these two treatments in adults with a single upper ureteric stone smaller than 10 mm and a stone density of 1000 Hounsfield units or less. Participants were assigned to receive either extracorporeal shock wave lithotripsy or semirigid ureteroscopy. The main outcome was complete stone clearance on non-contrast computed tomography four weeks after completion of the assigned treatment. Pain relief, number of treatment sessions and treatment-related complications were also assessed.

Intraoperative Assessment of of Burst Wave Lithotripsy (BWL)

Burst Wave Lithotripsy (BWL) is a novel method of urinary stone fragmentation that uses multi-cycle bursts of low amplitude ultrasound to induce stone fracture. This is in contrast to traditional extracorporeal shock wave lithotripsy (SWL), which employs a brief single compression/tensile cycle of high amplitude (shock) waves to achieve stone fracture. This is a single-arm feasibility study to test the ability of BWL to comminute (fragment) stones in humans.

ComfiJ Versus Conventional Double-J Stent for Ureteral Stent Symptoms

This prospective multicenter randomized controlled trial will compare stent-related symptoms after placement of a ComfiJ ureteral stent versus a conventional double-J ureteral stent in adult patients undergoing unilateral ureteroscopy or retrograde intrarenal surgery for urinary stones when short-term postoperative ureteral stenting is clinically indicated. Eligible patients will be randomized intraoperatively after the operating surgeon confirms the need for postoperative stenting. The primary outcome will be the Ureteral Stent Symptom Questionnaire urinary symptoms domain score on postoperative day 14 before planned stent removal.

Melatonin and Solifenacin for Double-J Ureteral Stent Symptoms

Double-J ureteral stents are commonly inserted after ureteroscopy, but they may cause bothersome urinary symptoms, pain, sleep disturbance, and reduced quality of life. This prospective randomized assessor-blinded three-arm clinical trial will compare oral solifenacin, oral melatonin, and their combination for improving ureteral stent-related symptoms in adult patients after unilateral ureteroscopic lithotripsy with insertion of a unilateral Double-J ureteral stent. Participants will be randomized to receive solifenacin 5 mg once daily, melatonin 3 mg once nightly, or combined solifenacin 5 mg once daily plus melatonin 3 mg once nightly for 14 days after surgery. The primary outcome is the total Ureteral Stent Symptom Questionnaire score at postoperative Day 7. Secondary outcomes include total Ureteral Stent Symptom Questionnaire score at Day 14, change in questionnaire score between Day 7 and Day 14, Insomnia Severity Index score, Visual Analogue Scale pain score, adverse events, treatment compliance, and rescue analgesic consumption.

Intravesical Aminophylline for Urgent Ureteral Stenting in Acute Calculous Anuria

Acute calculous anuria is a urological emergency caused by ureteral stone obstruction in a solitary functioning kidney or bilateral ureteral obstruction. Urgent decompression of the upper urinary tract is required to restore urine drainage and prevent further renal impairment. This prospective randomized double-blind controlled trial will evaluate whether intravesical aminophylline can facilitate urgent retrograde ureteral stenting in adult patients with acute calculous anuria due to ureteral stones. Eligible patients will be randomly assigned to receive either intravesical aminophylline diluted in normal saline or placebo saline before attempted retrograde Double-J ureteral stent placement. The primary outcome is technical success, defined as successful placement of a Double-J ureteral stent across the obstructing stone without the need for percutaneous nephrostomy. Secondary outcomes include stenting time, intraoperative complications, renal function recovery, postoperative pain, analgesic requirement, and the need for alternative drainage.

L-Citrulline Versus Tamsulosin for Medical Expulsive Therapy of Distal Ureteral Stones

This study will compare L-citrulline and tamsulosin as medical expulsive therapy for adults with single distal ureteral stones. Eligible participants with a single distal ureteral stone measuring 5 to 10 mm will be randomly assigned to receive either oral L-citrulline 750 mg twice daily or oral tamsulosin 0.4 mg once daily. Treatment will continue until documented stone passage or completion of 4 weeks of therapy, whichever occurs first. Participants will be followed weekly for up to 4 weeks. The main outcome is stone expulsion within 4 weeks. The study will also assess time to stone expulsion, pain episodes, analgesic use, need for additional intervention, and adverse events.

Intravesical Aminophylline to Facilitate Ureteroscopic Access in Children With Distal Ureteral Stones.

This study will evaluate whether intravesical aminophylline can facilitate semi-rigid ureteroscopic access in children with distal ureteral stones when the first gentle attempt to enter the ureter is unsuccessful. Children scheduled for semi-rigid ureteroscopy for distal ureteral stones will first undergo the standard gentle attempt to pass the ureteroscope through the ureteric orifice and intramural ureter. If access is achieved, the child will continue standard treatment and will not be randomized. If access is not achieved, the child will be randomized during the operation to receive either intravesical aminophylline or intravesical normal saline placebo. The study solution will be instilled into the bladder for approximately 5 minutes, then drained, and a second gentle ureteroscopic access attempt will be made. The main outcome is successful same-session passage of the intended semi-rigid ureteroscope without balloon dilation. The study will also assess the need for JJ stenting and deferred ureteroscopy, same-session stone treatment, operative outcomes, complications, and early aminophylline-related safety.

URSL Angle for Predicting Intraoperative Conversion

This international multicenter retrospective cohort study aims to externally validate the URSL Predictive Angle, a novel CT-derived morphometric parameter, as an imaging biomarker for predicting intraoperative conversion risk during transurethral ureteroscopic lithotripsy (URSL) for ureteral calculi. Intraoperative conversion is defined as the unanticipated abandonment of the planned endoscopic approach due to unfavorable ureteral anatomy or stone impaction, necessitating recourse to open ureterolithotomy, laparoscopic ureterolithotomy, or ureteral stent placement with planned staged secondary intervention. Such conversions are associated with protracted operative duration, heightened anesthetic exposure, and increased physical, psychological, and financial burdens on patients. The URSL Predictive Angle is a geometric parameter derived from preoperative coronal CT reformations that quantifies the degree of local ureteral angulation induced by an impacted calculus. Preliminary single-center data demonstrated robust predictive fidelity of this metric with an area under the ROC curve of 0.861 and an optimal discriminatory threshold of 131.8° yielding a sensitivity of 82% and a specificity of 88%. This study will enroll eligible patients from multiple domestic and international tertiary care hospitals who underwent URSL for ureteral calculi between January 1, 2018, and December 31, 2025. The primary outcome is intraoperative conversion of surgical approach. The predictive performance of the URSL angle will be evaluated using ROC curve analysis with AUC calculation. Propensity score matching and multivariable logistic regression will be employed to address potential confounding. This study is registered as a patient registry with a cohort model. Data collection is retrospective, involving abstraction from electronic medical records, operative logs, and PACS. A waiver of informed consent has been requested based on the retrospective design, minimal risk determination, stringent anonymization procedures, and impracticability of obtaining individual consent.

Impact of Humid-Heat on Gut-Tryptophan-Stone Pathway

Investigating the differences in gut microbiota composition and tryptophan metabolite levels between kidney stone patients and healthy individuals, with special focus on: 1. Comparing the gut microbiota composition between kidney stone patients and healthy controls, with emphasis on analyzing the relative abundance of Lactobacillus salivarius 2. Comparing the differences in tryptophan metabolite levels such as indole-3-carboxylic acid (ICA) and kynurenine (Kyn) in serum between the two groups 3. Exploring the correlation between gut microbiota composition and tryptophan metabolite levels 4. Analyzing the influence of different environmental conditions (seasons, temperature and humidity) on gut microbiota and metabolite levels

New Laser and Suction Sheath for Kidney Stone Treatment

The goal of this clinical trial is to learn if the combination of super pulsed thulium fiber laser (sTFL) with a flexible negative pressure suction sheath is more effective and safer than sTFL with a conventional sheath in treating kidney stones and/or ureteral stones. The main questions it aims to answer are: Does the sTFL with a flexible negative pressure suction sheath have a higher stone - free rate than the sTFL with a conventional sheath? Does the sTFL with a flexible negative pressure suction sheath have fewer complications than the sTFL with a conventional sheath? Researchers will compare the two treatment groups to see if there are differences in stone - free rate and complication rates. Participants will: Undergo ureteroscopic lithotripsy surgery. In the experimental group, have a flexible negative pressure suction sheath inserted along a guidewire to the stone site under general anesthesia, then have a ureteroscope inserted through the sheath to the stone site, and have the stone fragmented by sTFL with a power setting of 0.8J and a frequency of 12 - 20Hz while the fragments are removed by negative pressure suction. In the control group, have a conventional sheath inserted to the upper ureter or the ureteropelvic junction under general anesthesia, then have a ureteroscope inserted through the sheath to the stone site, and have the stone fragmented by sTFL with a power setting of 0.8J and a frequency of 12 - 20Hz and the fragments removed by a stone basket.