Clinical Research Directory

Urethral Resistive Index (URI): A New Parameter for Diagnosing Urethral Obstruction

This prospective observational study aims to evaluate the diagnostic accuracy of a new, non-invasive uroflowmetry parameter called the Urethral Resistive Index (URI) for detecting urethral stricture in men. Currently, diagnosing urethral stricture often requires invasive procedures like surgery or pressure-flow studies. This research seeks to develop URI as a practical and painless screening tool that could reduce the need for such invasive interventions. Study Procedures: A total of 60 male participants (30 with suspected urethral stricture and 30 healthy volunteers) will be enrolled. Participants will undergo two standard, non-invasive uroflowmetry (voiding) tests. The first test is a routine natural voiding session. The second test involves a "forced voiding" (Valsalva maneuver) once the participant feels a sufficient urge to urinate again. The URI is then calculated by comparing the flow rates of these two sessions. Goals and Benefits: The primary goal is to determine the optimal "cut-off" value of the URI that accurately identifies a surgically proven urethral stricture. By demonstrating URI's effectiveness, the study aims to expedite the diagnostic process and spare patients from unnecessary invasive tests. The procedure involves minimal risk, primarily temporary discomfort or psychological stress during the voiding tests

A Comparative Study of the Antibacterial Effects of Two Preoperative Hair Removal Methods in Male Patients With Urethral Stricture

Male urethral stricture is one of the common diseases in urology, with risk factors including a history of hypospadias surgery, indwelling urinary catheterization or instrumental manipulation, trauma, transurethral surgery, and prostate cancer treatment. Its main clinical manifestations are dysuria, weak urinary stream and frequent micturition, which seriously affect patients' quality of life. Surgery is the main treatment for moderate to severe urethral stricture. Among various surgical procedures, lingual mucosal urethroplasty and end-to-end urethral anastomosis are widely used in clinical practice due to their high long-term patency rates. However, postoperative complications still plague patients. According to reports, the incidence of urinary tract infection within 30 days after surgery ranges from 6.7% to 21%, and the incidence of surgical site infection (SSI) reaches 4.1%. SSI not only impairs surgical efficacy, but also may prolong hospital stay, increase medical costs and even lead to poor prognosis. As defined by the U.S. Centers for Disease Control and Prevention (CDC), SSI refers to surgery-related infections occurring within 30 days after surgery (or up to 1 year if an implant is present), which are specifically classified into three types: superficial incisional SSI, deep incisional SSI, and organ/space SSI. There are significant regional differences in the global incidence of SSI: it is approximately 2.8% in developed countries, while it can be as high as 22.8% in resource-limited regions, indicating an urgent need to optimize perioperative infection prevention and control strategies. The World Health Organization (WHO) has identified standardized preoperative skin preparation as one of the key measures for preventing SSI. The skin is the main source of bacterial colonization in the surgical area. In particular, the perineum, due to its moist environment, numerous folds and easy accumulation of secretions, is prone to becoming a breeding ground for opportunistic pathogens such as Escherichia coli, Klebsiella pneumoniae, Staphylococcus epidermidis and Enterococcus faecalis-all of which are common pathogenic bacteria causing postoperative infections in male patients with urethral stricture. Effective preoperative skin cleansing can significantly reduce the local microbial load and the risk of intraoperative contamination, thereby lowering the probability of postoperative infection. Therefore, preoperative skin preparation is not only a routine nursing procedure, but also a crucial component of perioperative infection control. Traditional preoperative skin preparation mostly involves wiping with warm water or normal saline, which can remove surface dirt but lacks sustained antibacterial effects and is difficult to effectively inhibit bacterial regrowth. In recent years, chlorhexidine gluconate (CHG) has gradually become the preferred product for preoperative skin disinfection due to its broad-spectrum antibacterial activity, rapid bactericidal effect and persistent residual action. A number of high-quality studies have confirmed that preoperative showering or local wiping with CHG can significantly reduce the incidence of SSI in orthopedic surgery, cesarean section and implantation of cardiac electronic devices. However, in the field of urology, especially for complex urethral reconstructive surgeries involving the perineal region (such as lingual mucosal urethroplasty and end-to-end urethral anastomosis), studies on the inhibitory effect of local CHG application on skin bacterial colonization and its clinical value remain scarce. Such surgeries are classified as "clean-contaminated" procedures, characterized by long operative time and extensive tissue exposure. In addition, some surgical techniques require tissue harvesting from the oral cavity, which brings the risk of multiple infection sources and imposes higher requirements for aseptic management of the surgical area. Existing studies mostly take postoperative infection rate as the endpoint indicator, and few focus on the impact of preoperative interventions on the dynamic changes of skin microorganisms. Quantitative detection of colony-forming units (CFU) and bacterial species distribution in key anatomical sites can more objectively evaluate the immediate and sustained bacteriostatic effects of different skin preparation methods, thereby revealing their underlying mechanisms of action. Therefore, this study intends to conduct a prospective research to compare the bacteriostatic effects of different preoperative skin preparation methods in the target population, so as to provide clinical practice with more evidence-based guidelines for perioperative skin preparation procedures.

REDUCER Trial (TXA in Urethroplasty)

This study will test whether tranexamic acid (TXA), a medication used to reduce bleeding, can decrease blood loss in patients having urethroplasty. Participants will be randomly assigned to receive either a single intravenous dose of TXA at the start of anesthesia or standard care without TXA. Researchers will compare hemoglobin change after surgery as well as estimated blood loss and complications.

The Impact of Age and Sex on Anticipated and Experienced Pain in First-Time Outpatient Flexible Cystoscopy

Cystoscopy is a procedure frequently performed in daily urological practice for the diagnosis of various urological conditions, including bladder tumors, benign prostatic hyperplasia, recurrent cystitis, and urethral strictures. Cystoscopy can be performed either in the operating room under sedation, spinal anesthesia, or general anesthesia, or in the outpatient setting under local anesthesia. Performing cystoscopy under outpatient conditions for patients requiring the procedure for follow-up and treatment indications is important in terms of reducing the workload of operating rooms. Although cystoscopy is generally well tolerated under local anesthesia in the outpatient setting, it may cause pain and anxiety in some patients, even when a flexible cystoscope is used. This may lead to adverse outcomes, particularly in patients with bladder tumors, due to loss to follow-up. Despite the use of analgesic methods such as lidocaine-based lubricants to reduce pain and anxiety before cystoscopy, an optimal solution has not yet been achieved. Moreover, some studies have reported that the level of pain experienced during cystoscopy increases with advancing age. In male patients, several studies have demonstrated that the most painful moment during cystoscopy occurs when the tip of the cystoscope passes through the external urinary sphincter. It has been shown that asking patients to take deep breaths or allowing them to watch cystoscopy videos while manually compressing the irrigation fluid bag during the passage of the cystoscope through the bulbar urethra, just distal to the external urinary sphincter, can reduce pain perception. Female patients tend to experience less pain due to the shorter urethral length. Various strategies have been employed to minimize pain and anxiety during the procedure, including listening to music, watching relaxing videos, or allowing patients to view their own cystoscopy recordings during the examination. Given the lack of prior cystoscopy experience, we planned this randomized prospective study to evaluate the effect of age and sex on pain perception during flexible cystoscopy. We believe that the findings of this study may be beneficial in counseling patients during cystoscopic evaluation of urological pathologies

Risk of Recurrent Urethral Stricture After Treatment With Paclitaxel-Coated Dilatation Balloon (Optilume) Compared With Non-coated Dilatation Balloon

Urethral strictures are often initially treated endoscopically with dilatation or direct visual internal urethrotomy (DVIU), a procedure where the stricture is incised through the vision of a cystoscope. These methods are easy to perform, they are often well tolerated under local anesthesia and they have a low risk of complications. One disadvantage is the relatively low success rate which is 20-60% when used as a first intervention and considerably lower after several interventions. Instead of repeated endoscopic procedures, it is advisable to perform open urethroplasty. Urethroplasty has a success rate of 65-91% but a higher risk of complications and requires general anesthesia. Therefore, there is a need for a treatment option for recurrent urethral strictures after DVIU or dilatation, before the urethroplasty is performed. Optilume is a CE-marked paclitaxel-coated dilatation balloon used for treatment of urethral strictures. The industry-sponsored randomised ROBUST III trial from 2022 showed a 75% success rate with Optilume but it is not sure if the results can be generalised to patients who would otherwise be candidates for open urethroplasty and whether the drug coating per se increases the efficacy of balloon dilatation. The aim of this study is to investigate whether the addition of paclitaxel-coating can increase the success rate and decrease the need for additional interventions and open urethroplasty for individuals who has a recurrent urethral stricture following at least one previous endoscopic intervention.

ROBUST III- Re-Establishing Flow Via Drug Coated Balloon For The Treatment Of Urethral Stricture Disease

ROBUST III is a prospective, multi-center, randomized controlled adaptive sample size clinical trial to establish the safety and effectiveness for the Optilume Stricture Drug Coated Balloon (DCB).

Optilume PoST AppRoval Clinical Evaluation of Andrology ParaMeters

Single-arm, prospective study assessing semen quality after treatment with the Optilume Urethral DCB in men between 22 and 65 years of age.

Bioengineered Collagen Implant for Urethral Stricture Repair

The field of research for this study is tissue engineering and the utilization of a bioengineered collagen implant as a substitute biomaterial for conventional buccal mucosa in substitution urethroplasty of distal urethral strictures.

Safety and Feasibility Study of Autologous Engineered Urethral Constructs for the Treatment of Strictures

This is a Phase I clinical study to determine the safety and efficacy of using autologous, engineered urethral constructs for the treatment of urethral strictures in adult males. The proposed study design is a prospective non-randomized and uncontrolled single-center investigation. Autologous urothelial cells (UCs) and smooth muscle cells (SMCs), obtained from enrolled male subjects' bladder tissue samples, will be culture expanded in vitro and used to seed tubular PGA scaffolds to create autologous urethral constructs for the repair of urethral strictures.

Penile Skin Versus Buccal Mucosal Graft in Augmentation Urethroplasty for Long Anterior Urethral Stricture

The aim of this study is to analyze the outcomes of dorsal onlay buccal mucosal graft (BMG) and penile skin graft (PSG) urethroplasty in the management of long segment bulbar urethral stricture.

Treatment of Bulbar Urethral Strictures With Optilume Drug-Coated Balloons in an Untreated Population

This randomized controlled trial investigates the effectiveness and safety of the Optilume® drug-coated balloon (DCB) compared to standard direct visual internal urethrotomy (DVIU) in the treatment of bulbar urethral strictures. The primary objective is to assess freedom from repeat intervention at 12 months. Secondary objectives include evaluating urethral patency, urinary symptoms, and sexual function through objective measures (Qmax, PVR, cystoscopy) and patient-reported outcomes (USS-PROM, IPSS, IIEF-5). The study will recruit 140 participants across multiple sites, with follow-ups conducted at 6 and 12 months. This trial seeks to provide evidence for Optilume DCB as a safe and effective alternative to standard treatment.

Multi-stage Urethroplasty with Augmentation Using a Dorsal Graft Inlay Technique Comparing Graft Use in First or Second Stage

The principal aim of this pilot study is to directly compare both approaches and analyze the failure rate after one year of follow-up. These data will serve as the basis to design a larger phase II or III trial in the future with failure rate as the primary end-point. Other study objectives are thoroughly described underneath.

Urethral Stricture Database

Establishment of a clinical urethral stricture database for a prospective longitudinal cohort study.

9000 URETHRA STUDY: a Study About Urethroplasty for Urethral Stricture Disease

It has been demonstrated that urethroplasty should be considered the gold standard treatment for urethral stricture disease as it yields higher long-term success rates than endoscopic treatment options such as direct vision internal urethrotomy (DVIU) or dilation. Many data about these procedures exist, although most of the publications about urethroplasty are retrospective and involve a tremendous risk of bias. To address these issues, this study is designed to prospectively gain evidence about this matter in all patient subgroups facing a potential treatment with urethroplasty: native men, native women, transmen, transwomen and children.