Histotripsy Treatment of Benign Prostatic Enlargement Using the Vortx R System: Initial Human Safety and Efficacy Outcomes.

Objective: To assess clinical safety (primary) and efficacy (secondary) of histotripsy for treatment of symptomatic benign prostatic enlargement in a first-in human study.

Methods: Twenty-five male subjects with moderate to severe lower urinary tract symptoms, prostate size between 30 and 80 g, and no evidence of prostate cancer were enrolled at 2 sites in a prospective, single-arm study. Treatment consisted of acoustic energy delivery through the perineum with integrated real-time transrectal ultrasound monitoring using the Vortx R system.

Systematic evaluation of hybrid guidewires: shaft stiffness, lubricity, and tip configuration.

Objective: To conduct a comparison of physical and mechanical properties for 5 commonly used guidewires to assess advantages of wires for specific applications.

Methods: Tests on guidewires (0.035" diameter; straight, flexible tip) included tip bending, shaft buckling, lubricity, and tip puncture measurements.

Systematic evaluation of a novel foot-pump ureteroscopic irrigation system.

Introduction: To evaluate forces exerted on a stone with different ureteroscopic irrigation systems.

Methods: A 3 mm steel simulated stone was welded to a 3F stone basket and inserted into the working channel of a 4.5F Wolf semirigid ureteroscope.

New metallic ureteral stents: improved tensile strength and resistance to extrinsic compression.

Background And Purpose: Extrinsic ureteral compression challenges a ureteral stent's ability to facilitate urinary drainage and to protect the kidney. Our purpose was to evaluate the performance of new metallic coil-based ureteral stents in terms of tensile strength and radial compression force.

Materials And Methods: Three stent designs tested from Prosurg Inc included Passage 7.

Small-diameter nitinol stone baskets: radial dilation force and dynamics of opening.

Purpose: To evaluate the radial dilation force and basket opening dynamics of three small (<1.5F) stone baskets.

Materials And Methods: Boston Scientific OptiFlex (1.

Comparison of small diameter stone baskets in an in vitro caliceal and ureteral model.

Background And Purpose: Three small diameter (<1.5F) stone baskets have recently been introduced. Our objective was to evaluate the stone capture rate of these baskets in an in vitro ureteral model and an in vitro caliceal model using novice, resident, and expert operators.

Resistance to extrinsic compression and maintenance of intraluminal flow in coil-reinforced stents (Silhouette Scaffold Device): an in vitro study.

Introduction: Stenting is the best approach to manage ureteral extrinsic compression and depends on intraluminal patency, which is mainly determined by cross-sectional stability. We evaluated the resistance to extrinsic compression of the Silhouette Scaffold Device and its ability to simultaneously maintain intraluminal flow.

Materials And Methods: Four 8 F Silhouette stents of different lengths were evaluated for radial compression and intraluminal flow by an MTS Micro Bionix Testing System using Testworks II software.

Next generation biodegradable ureteral stent in a yucatan pig model.

Purpose: Ureteral stents are commonly used to facilitate kidney drainage but they may produce significant stent symptoms and morbidity, and require a secondary procedure for removal. Previous biodegradable stents showed bio-incompatibility or inconsistent degradation, requiring extra procedures to remove undegraded stent fragments. We previously reported a first generation biodegradable stent composed of suture-like material that required placement through the lumen of a sheath and degraded by 10 weeks.

Uropathogen interaction with the surface of urological stents using different surface properties.

Purpose: Ureteral stents commonly become infected or encrusted. Various coatings have been developed to decrease bacterial adherence. To our knowledge there has been no in vitro testing of coating with heparin to date.

Celecoxib in the management of acute renal colic: a randomized controlled clinical trial.

Objectives: To evaluate the efficacy of celecoxib as an analgesic and medical expulsive agent in acute renal colic.

Methods: A prospective randomized double-blind study was conducted on patients presenting with an obstructing ureteral calculus < 10 mm in largest diameter. Patients were randomized to 400 mg of celecoxib, followed by 200 mg every 12 hours for 10 days, or to placebo.

Ureteral obstruction: is the full metallic double-pigtail stent the way to go?

Background: The Resonance metallic ureteral stent (Cook Medical, Bloomington, Indiana, USA) has been introduced for the management of extrinsic-etiology ureteral obstruction for time periods up to 12 mo.

Objective: The current study aims to determine short- and medium-term effectiveness of the Resonance stent in malignant and benign ureteral obstruction.

Design, Setting, And Participants: In total, 50 patients with extrinsic malignant obstruction (n=25), benign ureteral obstruction (n=18), and previously obstructed mesh metal stents (n=7) were prospectively evaluated.

Foley catheter characteristics: predicting problems.

Purpose: To evaluate the physical properties of urethral catheters that are predictive of ease of placement and risk of urethral trauma: Stiffness, buckling, and friction forces.

Materials And Methods: Eleven Bard Lubri-Sil and 10 Kendall Dover 16F Foley catheters were tested using a linear motion stage driven by a stepper motor with a resolution of 5 microns/step or by hand. Force was measured at a sampling rate of 5 Hz with a Wagner FDIX digital force gauge.

Radial dilation of nephrostomy balloons: a comparative analysis.

Purpose: The dynamics of percutaneous balloon expansion may differ with increasing extrinsic compressive forces and increasing inflation pressures. This study compares the ability of percutaneous balloons to expand under different radial constrictive forces.

Materials And Methods: Three 30F nephrostomy balloons were tested: Bard X-Force, Boston Scientific Microvasive Amplatz Tractmaster, and Cook Ultraxx.

Evidence-based instrumentation for flexible ureteroscopy: a review.

Instrumentation is the key to success in endourology. Indeed, endourology could be redefined as "enginurology," as the marriage between engineering and urology, and developing instrumentation to improve patient outcomes is the key facilitator in the advancement of minimally-invasive techniques. This review article will identify the evidence base that supports our current recommendations for equipment used during ureteroscopy.

Alfuzosin stone expulsion therapy for distal ureteral calculi: a double-blind, placebo controlled study.

Purpose: We evaluated the efficacy of alfuzosin as medical expulsive therapy for distal ureteral stone passage.

Materials And Methods: A total of 76 patients with a distal ureteral calculus provided consent for the study. Patients were randomized between placebo and study medication, and investigators and patients were blinded to the randomization scheme.

Impact of irrigation systems on stone migration.

Purpose: To evaluate forces exerted on a stone with different ureteroscopic irrigation systems that could impact stone migration during ureteroscopy.

Materials And Methods: A 3-mm steel simulated stone was welded to a 3F stone basket. The basket wire was then backloaded into the working channel of a 4.

Wire-based ureteral stents: impact on tensile strength and compression.

Objectives: To evaluate the performance of coil-based ureteral stents in terms of tensile strength and the radial compression force.

Methods: Three Cook Resonance (RES) metallic coil stents and three coil-reinforced Applied Medical Silhouette (SIL) ureteral stents were tested. An MTS MicroBionix Testing System using Testworks II software, vibration isolation table, and 5-N load cell were used to measure tensile and compressive strength.

Lateral deflection to release a stone: a simple method.

We describe and demonstrate a simple method to release a stone from a basket that emphasizes the importance of lateral deflection of the ureteroscope while opening and advancing the basket. This technique works well with semirigid and flexible ureteroscopes and all stone baskets, although some difficulty may be encountered with flat-wire baskets.

In vitro evaluation of ureteral perforation forces.

Objectives: Ureteroscopy has become a very effective treatment option for ureteral and upper tract abnormalities. The reported complication rates have ranged from 1.5% to 13% for perforations and have been less than 1% for avulsions.

Physical characteristics of next-generation ureteral access sheaths: buckling and kinking.

Objective: To evaluate physical characteristics of next-generation access sheaths that impact clinical failure.

Methods: Testing of the Cook Flexor (12/14 Fr x 35 cm, Cook), ACMI UroPass (12/14 Fr x 38 cm, ACMI), Bard Aquaguide (11/13 Fr x 35 cm Bard), and Boston Scientific Navigator (11/13 Fr x 36 cm BSCI-11, 13/15 Fr x 36 cm BSCI-13) was performed on a linear motion stage driven by a stepper motor with a resolution of 5 microm per step. Force was measured at a sampling rate of 5 Hz with a Wagner FDIX digital force gauge.

A pilot study on the early use of the vacuum erection device after radical retropubic prostatectomy.

Objective: To evaluate the effect of the early use of the vacuum erection device (VED) on erectile dysfunction (ED) and penile shortening after radical retropubic prostatectomy (RP), as these are important concerns for men choosing among treatment alternatives for localized prostate cancer.

Patients And Methods: Twenty-eight men undergoing RP were randomized to early intervention (1 month after RP, group 1) or a control group (6 months after RP, group 2) using a traditional VED protocol. An International Index of Erectile Function (IIEF) score of >11 (no, mild or mild to moderate ED) was required as a baseline criterion for inclusion in the study.

Novel technique for removal of misdirected laparoscopic Weck clips.

The Weck clip has emerged as an attractive option for laparoscopic vascular control. It is secure and easy to use. However, once fired, the clip can be difficult to remove.

Randomized prospective evaluation of nephrostomy tube configuration: impact on postoperative pain.

Objective: Conduct a prospective randomized single-blind comparison of two nephrostomy catheter designs, evaluating specifically intraoperative placement and postoperative comfort.

Materials And Methods: The single-blind, prospective randomized trial was conducted with institutional review board approval. All patients undergoing percutaneous nephrolithotomy who gave informed consent were randomized to placement of either a Boston Scientific Flexima 8.

Ureteral stents: coil strength and durometer.

Objectives: To evaluate the coil strength before and after urine exposure and the stiffness of commercially available double-J ureteral stents because both properties may affect stent performance and patient comfort.

Methods: Twelve commercially available 6F ureteral stents were tested for coil strength before and after 30 days of urine exposure. The proximal end of each stent was inserted through a 2-mm hole in bologna, allowed to recoil, and then pulled using a handheld force gauge.

In vitro evaluation of ureteral stent compression.

Objectives: To evaluate the force required to radially compress ureteral stents and the impact of compression on stent performance across a broad range of stent sizes and manufacturers.

Methods: Fourteen ureteral stents ranging in size from 6F to 10.3F were evaluated for radial compression using an MTS Micro Bionix Testing System using Testworks II software, 5N load cell, vibration isolation table, and socket set screws with rounded caps.