Noninvasive assessment of detrusor pressure and dysfunction

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Lower urinary tract symptoms are highly prevalent in adult men and women, with an estimated prevalence of up to 50%, and can have a significant impact on quality of life. Urodynamic studies (UDS) are routinely performed in the assessment of lower urinary tract symptoms. Presently, UDS is used in the clinic to detect detrusor overactivity. Detrusor overactivity is caused by unintentional transient contraction of the bladder detrusor muscle, increasing the internal pressure in the bladder. Detrusor overactivity is a common problem. It is estimated that 20% of the total population suffer from overactive bladder, and of those with overactive bladder who are tested by UDS, 65% have detrusor overactivity. Another application of UDS is to assess bladder function in men with benign prostatic hyperplasia (BPH). BPH is a common clinical entity. Millions of men develop lower urinary tract symptoms and seek treatment for this entity. Surgery to de-obstruct the urinary tract may be pursued to treat these patients. Clinically, a UDS test includes the use of multiple pressure catheters (placed in the bladder and rectum/vagina), retrograde bladder filling for an assessment of urinary storage function, and a pressure-flow study to assess for abnormalities of the voiding phase. UDS is limited by its invasiveness, patient discomfort, testing artifacts, and the risk of complications. Adverse outcomes, including urinary retention, catheter trauma, or hematuria, are reported in up to 19% of men and 1.8% of women. Considering UDS limitations, there is a need for a noninvasive alternative to UDS. To overcome the limitations of UDS, we propose a noninvasive ultrasound technique, Quantitative Ultrasound Bladder Vibrometry (QUBV). This technique measures changes in the detrusor’s pressure due to detrusor overactivity. Since this method does not require catheterization, it does not expose the patients to the risks and discomfort associated with UDS. Other advantages of QUBV include a direct measure of the detrusor pressure without the influence of bowl contractions, low cost, and portability. Also, since QUBV is noninvasive and low cost, it is suitable for repeated longitudinal tests for monitoring and evaluating response to treatment. The goal of this project is to evaluate the efficacy of QUBV applications in detrusor overactivity and BPH. To achieve our goal, we propose the following Specific Aims: (1) Evaluate the performance of quantitative ultrasound bladder vibrometry (QUBV) in diagnosing detrusor overactivity; (2) Prognostically determine and monitor patients with BPH that may benefit from surgery to de-obstruct the urinary tract. Each Aims will be tested in a population of patients. Our team has over a decade of experience in developing new technology for application in urology, thus has the expertise and resources to achieve the goals of this project. Also, the project benefits from the world-class clinical research and facilities at the Mayo Clinic. Successful completion of this project may have a significant impact on the diagnosis and management of bladder dysfunction.