Hideo Ozawa

Extracorporeal magnetic innervation treatment for urinary incontinence

Abstract  Background:  Extracorporeal magnetic innervation (ExMI) is a new technology used for pelvic muscle strengthening for the treatment of stress urinary incontinence. We explored whether this new technology is effective for patients with urge incontinence, as well as those with stress urinary incontinence.

Intravesical resiniferatoxin for patients with neurogenic detrusor overactivity

Background: Resiniferatoxin (RTX), a substance isolated from some species of Euphobia, is a specific C‐fiber neurotoxin which produces desensitization rather than excitation. At first, we performed intravesical RTX therapy on eight patients with neurogenic detrusor overactivity. After we confirmed the safety and efficacy, a Japanese RTX study group was organized and a new protocol made. The multicenter trial was performed in Japan. However, the efficacy of the treatments was different among the institutions. Therefore, we have compared the results between the first protocol and the new one at our hospital.

Noninvasive urodynamic evaluation of bladder outlet obstruction using Doppler ultrasonography

OBJECTIVES Previously we had developed a new method of noninvasive urodynamics using color Doppler ultrasound. Using this technique, we attempted to identify parameters that would diagnose bladder outlet obstruction (BOO). METHODS Twenty-two men who underwent pressure-flow urodynamic studies were included. Color scale transperineal ultrasound and uroflowmetry data were analyzed by custom-made software. The maximum flow velocities in the entire prostatic urethra (V(0)), in the distal prostatic urethra just proximal to the external urethral sphincter (V(1)), and in the membranous urethra (V(2)) were obtained. Corresponding functional cross-sectional areas of the urethra at these three sites (A(0), A(1), and A(2)) were calculated as Qmax/V. The velocity ratio (VR), which was equal to V(1)/V(2), was also calculated as a parameter. All these parameters obtained by the velocity-flow urodynamics were compared with the Abrams-Griffiths number (AG). RESULTS From the x-y plots obtained, VR correlated best with AG, with Spearmans rho of 0. 728. A(0) and A(1) had rho values of -0.461 and -0.708 against AG, respectively. All men with VR exceeding 1.6 had obstruction, whereas those with VR less than 1.1 did not. CONCLUSIONS The VR was found to be the best parameter for diagnosing BOO. When prostatic urethral obstruction was present, the velocity in the prostatic urethra would be high but the velocity slows down to 62.5% or greater immediately below the sphincter. We believe that noninvasive pressure-flow-like urodynamic evaluation based on Doppler ultrasound has clear potential for diagnosing BOO.

Reliability of color Doppler ultrasound urodynamics in the evaluation of bladder outlet obstruction

OBJECTIVES To analyze the intrarater and interrater reliability of a newly developed noninvasive urodynamic technique based on color Doppler ultrasound for the evaluation of bladder outlet obstruction. We previously demonstrated the feasibility of this new technique. METHODS Color Doppler ultrasound urodynamic evaluations were performed on 31 men with and without bladder outlet obstruction. An ultrasound image-directed Doppler system with a 3.75-MHz probe operated by a remote control robotic manipulator was used to obtain color scale data using the transperineal approach in men during voiding. We measured the flow velocities in the distal prostatic (V1) and membranous urethra (V2) and used them to obtain the velocity ratio (VR = V1/V2). Combining this information with simultaneous uroflowmetry, the functional cross-sectional area of the distal prostatic urethra (A1) was calculated. These parameters were independently reinterpreted by an inexperienced investigator using the color image data stored in a personal computer. The intrarater and interrater reliability for VR were assessed using a classification based on cutoff values previously shown to indicate the presence or absence of obstruction. RESULTS The retest correlation using Spearmans rho for VR in terms of intrarater and interrater reliability was 0.95 and 0.57, respectively; that for A1 was 0.97 and 0.64, respectively. Using a VR of less than 1.1 (to indicate the absence of obstruction) and a VR greater than 1.6 (to indicate the presence of obstruction) for classification, intrarater and interrater agreement occurred in 93.6% to 96.8% and 77.4% to 83. 9% of cases, respectively. CONCLUSIONS The color Doppler ultrasound urodynamic technique for noninvasive evaluation of bladder outlet obstruction can be performed with reasonable reliability.

Endoscopic correction of vesicoureteral reflux by subureteric Teflon (polytetrafluoroethylene) injection: review of 6-year experience.

Background:

Basic study on velocity‐flow urodynamics using Doppler sonography: Simultaneous detection of cavitation and Doppler signals in an artificial urethral model

Abstract  Background:  We have developed velocity‐flow urodynamics using Doppler sonography based on the hypothesis that microbubbles formed in the urethra are responsible for Doppler signals. In order to confirm this hypothesis derived from Bernoullis principle, we investigated the simultaneous detection of cavitation noise and Doppler signals in an experimental system.

Use of Doppler ultrasound for non-invasive urodynamic diagnosis

Objectives: A totally non-invasive transperineal urodynamic technique using Doppler ultrasonography has been developed. Methods: Since normal urine does not have blood cells, urine was thought not to produce the Doppler effects. However, basic studies confirmed that the decrease of pressure at high velocity (Bernouilli effect) caused dissolved gas to form microbubbles, which are detected by Doppler ultrasonography. Subjects sat and the probe was advanced via remote control to achieve gentle contact with the perineal skin. The digital uroflow data signals and the color Doppler ultrasound video images were processed on a personal computer. The flow-velocity curves from two sites; the distal prostatic urethra just above the external sphincter (V1) and the sphincteric urethra (V2) were plotted against time. The parameters of both the pressure-flow studies and the Doppler ultrasound urodynamic studies were compared in men who had various degrees of obstruction. Results: Functional cross-sectional area at prostatic urethra (A1), calculated by Qmax/V1, was lower in the group of bladder outlet obstruction (BOO) vs. control group. Velocity ratio (VR), which was calculated by V1/V2, was the parameter having the best correlation with BOO index, though A1 had a similar correlation. This method is viable to diagnose the degree of BOO. Conclusions: The development of non-invasive Doppler ultrasound videourodynamics (Doppler UDS) will dramatically expand the information on voiding function.

Change in Parameters before and after Alpha-1-Blocker Therapy for Men with Lower Urinary Tract Symptoms Using Color Doppler Ultrasound Urodynamics: Possible Application for Prediction of Clinical Outcome

Introduction: We previously developed a noninvasive video urodynamic study using color Doppler ultrasonography. We sought the best flow velocity-related parameter which would allow prediction of an improvement in lower urinary tract symptoms (LUTS) after α₁-blocker treatment. Methods: Twenty-two men with benign prostatic hyperplasia who were treated with a nonselective α₁-blocker (urapidil) were included. Subjective symptoms were evaluated using the International Prostate Symptom Score (IPSS) before and after α₁-blocker treatment. We measured the flow velocities using a transperineal ultrasound technique in the distal prostatic urethra just proximal to the external urethral sphincter (V₁) and in the sphincteric urethra (V₂), and used them to obtain the velocity ratio (VR = V₁/V₂). The corresponding functional cross-sectional areas of the urethra at these two sites (A₁ and A₂) were calculated as Q_max/V. All these parameters obtained by the velocity-flow urodynamics were compared before treatment and after 4 weeks. Results: After treatment, V₁ and VR were decreased, and A₁ was increased. V₂ correlated best with the change in IPSS before and after α₁-blocker therapy, with Spearman’s rho of 0.584. All men with V₂ exceeding 50 cm/s did not show an improvement in the LUTS. Conclusions: The maximum flow velocity at the sphincteric urethra (V₂) can predict the subjective outcome of α₁-blocker treatment. The velocity-flow parameters changed after α₁-blocker treatment. We confirmed that the transperineal ultrasound urodynamic study is not only noninvasive but also informative.

URODYNAMIC CHANGES AFTER ENDOSCOPIC CORRECTION OF VESICOURETERAL REFLUX

Massive bilateral vesicoureteral reflux (VUR) in a 7‐year‐old girl with spinal scoliosis was successfully treated by endoscopic correction. She was admitted due to a febrile urinary tract infection and urinary incontinence. A cystometrogram demonstrated normal detrusor function during storage. The endoscopic subureteric injection of polytetrafluoroethylene (TeflonTM) was performed, resulting in the disappearance of the VUR. A postoperative cystometrogram demonstrated overactive detrusor function during storage, necessitating anticholinergic medication. She has been free of febrile urinary tract infections and incontinence for 2 years postoperatively, although self‐catheterization is necessary. In a case of neurogenic vesical dysfunction with massive reflux, endoscopic subureteric injection is not only a therapeutic tool, but also a useful diagnostic option for detecting occult detrusor overactivity during storage prior to open surgery.