Clinical Research Directory

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

Gut Oxalate Absorption in Calcium Oxalate Stone Disease

The goal of this clinical trial study is to test if patients with idiopathic calcium oxalate kidney stones have an increased absorption of dietary oxalate, 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 and moderately high amounts of oxalate for 5 days at a time * ingest a soluble form of oxalate and sugar preparations to test gut permeability * collect urine, blood, stool and breath sample during the fixed diets and the soluble oxalate test

O. Formigenes Colonization in Calcium Oxalate Kidney Stone Disease

The goal of this trial is to test if colonization with the gut bacteria Oxalobacter formigenes leads to a reduction in urinary oxalate excretion in patients with calcium oxalate kidney stone disease. The study will recruit adult participants with a history of calcium oxalate kidney stones who are not colonized with Oxalobacter formigenes. Participants will * ingest fixed diets containing low and moderately high amounts of oxalate for 4 days at a time * collect urine, blood and stool samples during the fixed diets * ingest a preparation of live Oxalobacter formigenes to induce colonization with Oxalobacter formigenes

Trial to Assess the Efficacy of EMPAgliflozin and Personalized Dietary Counseling for Kidney STONE Prevention

The aim of this randomized trial with a 2-by-2 factorial design is to test the efficacy of the SGLT2 inhibitor empagliflozin and personalized dietary counseling based on 24-hr urine collection results and dietary assessments for kidney stone recurrence prevention in patients with calcium kidney stones. Study interventions: * Empagliflozin 10 mg once daily per os for 36 months * Personalized dietary counseling for 36 months. Control interventions: * Placebo once daily per os for 36 months * Generic dietary counseling for 36 months.

Dual-process Mechanisms of Action for sipIT Intervention Effects in Patients With Urolithiasis

The purpose of this study is to clarify the fundamental processes underlying behavior change, maintenance, and adherence during and after a 3-month fluid intake intervention period.

HoYAG vs TFL in miniPCNL With ClearPetra

Mini percutaneous nephrolithotripsy is the treatment of choice for kidney stones over 2cm. This procedure commonly uses laser energy for breaking the stones, and among possible laser platforms, Hoyag and thulium fiber laser are FDA approved. Recently, this procedure has also included the use of vacuum assisted renal access sheaths, which allows suction to be employed together with the breaking of stones. This study intends to compare outcomes when using either laser platforms with suction sheaths in participants undergoing mini percutaneous nephrolithotripsy for the treatment of kidney stones.

ClearPetra™ Vacuum-assisted Ureteral Access Sheath vs Traditional Approach

Ureteroscopy has been considered the best approach when treating renal stones smaller than 2 cm. This procedure is usually performed together with ureteral access sheaths, which helps protect the ureter mucosa and lowers intrarenal pressure. Recently, a new vacuum-assisted ureteral access sheath called ClearPetra has entered US market and allows for continuous stone fragmentation and aspiration. Because there is little information on comparing this device with traditional approach (no sheath or non-vacuum-assisted sheath) in American population, we aim to compare those devices in terms of their ability to clear the kidney from kidney stones, as well as reduce infection rates postoperatively.

SOUND Pivotal Trial - (Sonomotion stOne comminUtion resoNance ultrasounD)

The goal of this clinical trial is to test the Break Wave™ system in patients with upper urinary tract stones. The main question it aims to answer is whether the device is safe and effective in fragmenting (breaking) stones. Participants will a) undergo the Break Wave™ procedure, b) have a telehealth visit at 2 weeks, and c) return for an imaging study at approximately 10 weeks post-procedure.

Evaluation of the LithoVue Elite Ureteroscope With Intra-Renal Pressure Monitoring Technology: Examination of Surgeon Behavior and Post-operative Outcomes

The goal of this study is to evaluate the influence of real-time intrarenal pressure measurement availability on surgeons' behavior during ureteroscopy while using the ureteroscope LithoVue Elite.

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.

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.

Effect of Comprehensive Spa Care on Kidney and Urological Conditions: A Clinical Study in Adult Patients

This is a single-arm, pretest-posttest study evaluating the effects of a 21-day comprehensive spa care (Komplexní lázeňská léčebně rehabilitační péče, KLP) on patients with nephrological and urological conditions treated at a spa facility in Mariánské Lázně, Czech Republic. The study enrolls 150 adult patients (75 men and 75 women), aged 40-70 years, who are prescribed KLP for indications VIII/1 (recurrent and chronic non-tuberculous inflammation of the kidneys and urinary tract), VIII/2 (nephrolithiasis without urinary tract obstruction, nephrocalcinosis), VIII/3 (conditions after kidney and urinary tract surgery), and VIII/4 (chronic prostatitis or prostatovesiculitis resistant to pharmacological treatment). The spa treatment consists of the use of natural healing resources of Mariánské Lázně, including a mineral spring drinking cure, balneotherapy (mineral water baths), peloid therapy, carbon dioxide therapy, climatotherapy, exercise therapy, and dietotherapy. The standard treatment duration is 21 days, during which each patient receives a total of 63 therapeutic procedures and drinks mineral spring water three times daily. Patients undergo assessments at the beginning (days 1-3) and at the end (days 19-21) of their treatment. Assessments include physical examination, abdominal and urinary tract ultrasound, blood and urine sampling with laboratory analysis, body composition measurement using bioelectrical impedance analysis (InBody), and psychometric questionnaire surveys. The primary aim of the study is to objectively assess the therapeutic effect of comprehensive spa care on nephrological and urological diseases by comparing pre-treatment and post-treatment clinical, laboratory, and patient-reported outcomes. The study was approved by the Ethics Committee of the University Hospital and Faculty of Medicine in Pilsen (decision of November 2, 2023, ref. no. 437/23).

Effect of Complete Suction-Induced Collapse of the Renal Collecting System at the End of RIRS on Early Postoperative Outcomes

The purpose of this study is to evaluate whether actively suctioning the renal collecting system to induce a "collapse" state at the end of retrograde intrarenal surgery (RIRS) can reduce postoperative pain and infection in patients with kidney stones. Participants will be randomly assigned to either the experimental group (suction-induced collapse) or the control group (standard drainage). The study aims to determine if this simple surgical modification can improve early recovery outcomes and patient satisfaction.

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 2 to 3 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

Erector Spinae Plane Block for Percutaneous Nephrolithotomy

Percutaneous nephrolithotomy (PCNL) is an effective standard urological procedure for the fragmentation and removal of large renal calculi. Although PCNL is performed as a minimally invasive technique, dilation of the renal capsule and parenchymal tract, as well as peritubular distension caused by the nephrostomy tube, may result in severe postoperative pain. Various analgesic strategies have been described in the literature for postoperative pain management following PCNL. These include systemic opioids, nonsteroidal anti-inflammatory drugs (NSAIDs), and several regional analgesia techniques. However, due to their adverse effect profiles, opioids and NSAIDs are not ideal options, particularly in patients with renal dysfunction. Regional techniques that have been utilized include local infiltration, intercostal nerve blocks, paravertebral blocks, and epidural analgesia. The kidney is primarily innervated between the T10 and L1 segments, whereas the ureter receives innervation from T10 to L2. Based on this anatomical knowledge, unilateral regional blockade between T10 and L2 can provide adequate analgesia for PCNL procedures. Thoracic paravertebral block was previously a commonly preferred technique; however, it may be associated with complications such as intravascular injection, unintended epidural or intrathecal spread, and pneumothorax during its performance. In recent years, the number of reports describing the use of the erector spinae plane block (ESPB) as part of multimodal anesthesia for postoperative analgesia has increased. In ESPB, local anesthetic is injected into the interfascial plane between the transverse process of the vertebra and the erector spinae muscles, and has been reported to spread to multiple paravertebral spaces. ESPB is considered a peri-paravertebral block that can affect both visceral and somatic pain pathways. The aim of this study is to evaluate the effect of ultrasound-guided erector spinae plane block on intraoperative and postoperative opioid consumption, postoperative pain scores, and quality of recovery in patients undergoing percutaneous nephrolithotomy.

Sodium Bicarbonate as an Alternative to Potassium Citrate for Kidney Stones

Kidney stones affect 1 in every 11 people in the US each year. In patients with kidney stones who are prescribed medications for stone management, only 30.2% are adherent to a medication regime and even fewer, only 13.4 % are adherent with citrate medications. Prescription potassium citrate can be expensive for many patients, leading to non-compliance. Sodium bicarbonate is a potential medication alternative that is cheaper and can potentially alkalinize the urine and/or decrease the risk of future kidney stones. However, efficacy of alternatives to potassium potassium citrate are not well studied. This study seeks to evaluate sodium bicarbonate and assess its ability to alkalinize urine in a cohort of patients with kidney stones and compare this to prescription potassium citrate.

Metaphylaxis of Infected Kidney Stones After Percutaneous Nephrolithotripsy

Kidney stone recurrence, particularly infection-related stones, remains a significant clinical problem after percutaneous nephrolithotripsy (PCNL). Bacterial colonization and persistent infection are recognized contributors to stone recurrence. This study evaluates the effectiveness of intrarenal dioxidine instillation as a metaphylactic measure to reduce recurrence of infection-related kidney stones following PCNL. Patients undergoing PCNL will receive standard treatment, with or without adjunctive intrarenal dioxidine administration. The study aims to assess whether this approach reduces stone recurrence and infection-related complications.

Comparison Between Different Types of Flexible Ureteroscopes

The current study aims to compare the performance of three distinct single-use digital flexible ureteroscope types in terms of cost-effectiveness, postoperative complications, operating time, and stone-free rates (SFRs).

Comparison of Extracorporeal Shock Wave Lithotripsy Versus Retrograde Intrarenal Surgery in the Management of Renal Calculi

This study is being carried out in patients with kidney stones measuring between 1 and 2 centimeters. Kidney stones are common in Pakistan and can cause severe pain, infection, and repeated hospital visits. Two commonly used treatments for stones of this size are extracorporeal shock wave lithotripsy (ESWL) and retrograde intrarenal surgery (RIRS). ESWL uses shock waves applied from outside the body to break the stone into small fragments that can pass in the urine. RIRS is a minimally invasive endoscopic procedure in which a thin flexible scope is passed through the urinary passage into the kidney and a laser is used to break the stone. Adult patients aged 18 to 65 years with a single kidney stone of 1-2 cm will be included. According to the urologist's clinical judgment and patient preference, individuals will undergo either ESWL (Group A) as a day-care shock wave procedure or RIRS (Group B) under general anesthesia using a laser. All patients will receive standard care before and after the procedure and will be followed for 28 days. The study will compare how completely the stone is cleared (based on a CT scan), how long patients stay in hospital, how much pain they feel after the procedure, and whether they develop visible blood in the urine or signs of infection such as fever and raised white cell count. The need for any further procedure for the same stone will also be recorded. The central hypothesis is that there is a meaningful difference between ESWL and RIRS in stone clearance, safety, pain, and need for retreatment. The findings are expected to help doctors and patients choose the most suitable treatment for kidney stones of this size in routine practice.

Is CYP24A1 Heterozygosity a Risk Factor for Nephrolithiasis?

Biallelic loss-of-function variants in CYP24A1 have been identified as a common genetic cause of autosomal recessive hypercalcemia (ARH, ORPHA 300547, 1 in 80,000 live births), characterized by low PTH (parathyroid hormone) levels, a high 25-OH D/24,25-(OH)₂D ratio, and susceptibility to vitamin D intoxication. In humans, heterozygous pathogenic variants in CYP24A1 have been proposed both as responsible for an autosomal dominant disorder and as a risk factor for nephrolithiasis, but the rarity and heterogeneity of human data prevent a definitive answer to this crucial question. Nephrolithiasis is a complex disease in which nutritional factors - particularly sodium and protein intake (leading to hypercalciuria) - play a key role. It also has a heritability of 50%, suggesting the involvement of many genetic susceptibility factors, as well as monogenic forms (mainly autosomal recessive, but also dominant or X-linked), which have been identified in 10-20% of patients. The increasing prevalence of nephrolithiasis, affecting approximately 10% of the general population over a lifetime, has a significant financial impact on healthcare systems and imposes a major burden of morbidity, justifying further investigation into the genetic underpinnings of nephrolithiasis. The goal of the HeteroCYP project is to improve understanding of the phenotypes associated with heterozygous, compound heterozygous, and homozygous variants of CYP24A1 by comparing clinical and biological outcomes in patients according to their mutation type

Postoperative Analgesia Practices After Percutaneous Nephrolithotomy

This prospective observational study aims to evaluate the effectiveness and safety of different postoperative analgesia methods used in patients undergoing percutaneous nephrolithotomy (PCNL). Analgesia techniques are determined independently by the responsible anesthesiologist as part of routine clinical practice, and the study team does not intervene in treatment decisions.

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.

Intravesical Bupivacaine on Post-Operative Ureteroscopy Pain

Post-operative pain and lower urinary tract symptoms are common following ureteroscopy in the treatment of stone disease. The use of bupivacaine as a topical pain medication is used routinely for other urologic procedures, however, to date there are no studies that have rigorously investigated the effect of instilling bupivacaine in the bladder following ureteroscopy. This is a randomized study that will investigate the effect of instilling bupivacaine in the bladder following routine ureteroscopy, laser lithotripsy and ureteral stenting in the treatment of stone disease. Compared to a placebo of Normal Saline, our study hypothesizes that administration of topical bupivacaine in the bladder will decrease post-operative pain and lower urinary tract symptoms while improving quality of life in the early post-operative period.