Amplifying Sensation in Underactive Bladder (AMPLIFY)

AMPLIFY: Amplifying Sensation in Underactive Bladder

The purpose of this study is to determine the influence of intravesical (bladder) electrical stimulation and intraurethral electrical stimulation on bothersome symptoms and bladder function in neurologically-intact adult women with underactive bladder. The investigators hypothesize that electrical stimulation will decrease bothersome urinary symptoms relative to baseline and increase voided percentage during pressure-flow studies compared to their routine clinical exam.

Study Overview

• Status: Recruiting
• Conditions: Urinary Bladder, Underactive
• Intervention / Treatment: Device: Neurometer Neurotron CPT; Procedure: Cystometry; Procedure: Pressure-flow study

Detailed Description

1. Objective: The overall objective of this study is to improve lower urinary tract symptoms (LUTS) in adult neurologically-intact women with underactive bladder through electrical stimulation of bladder sensory nerves or urethral sensory nerves.

2. Background and Significance: The storage and elimination of urine is regulated by neural circuits in the brain and spinal cord to coordinate function between the urinary bladder and the urethra. During micturition (bladder emptying), the elimination of urine is facilitated by bladder muscle (detrusor) contraction and urethral and pelvic floor muscle relaxation. Urine flow through the urethra also activates sensory nerves to amplify bladder contractions and maintain efficient bladder emptying. Incomplete emptying and urinary retention occur when these mechanisms are disrupted or poorly coordinated.

   Incomplete emptying due to underactive bladder is a poorly understood health concern that symptomatically affects up to 40% of the population, with the highest prevalence of symptoms in older men and women. Despite the high prevalence of symptoms, the diagnosis of an underactive bladder remains low due to the lack of consistent terminology and standardized diagnostic criteria. This results in defining underactive bladder by a symptom complex that may involve reduced motor drive (detrusor underactivity) during bladder emptying and/or reduced sensory drive during filling and emptying. Symptoms experienced by persons with underactive bladder include nocturia, urinary frequency, urgency, incontinence, slow stream, hesitancy, straining, and sensation of incomplete emptying. The most common symptoms are nocturia, slow stream, frequency, hesitancy, and the impact of these symptoms on quality of life is substantial for many patients.

   The management options for persons with underactive bladder include double-void, intermittent self-catheterization, or pharmacotherapy. However, these treatments are associated with poor quality of life and patients often fail to completely resolve the lower urinary tract symptoms (LUTS). There is a need to clarify the pathological mechanisms underlying underactive bladder to improve therapeutic outcomes. One approach to clarify reduced sensory drive is to evaluate the functional integrity of sensory nerves with quantitative sensory testing. Current perception threshold (CPT) testing delivers electrical stimulation to activate nerve fibers that evoke sensory perception, and changes in bladder sensory pathways were demonstrated in persons with diabetic detrusor underactivity. These diagnostic tests, however, have not been applied to neurologically intact adult women with underactive bladder and may provide insight into pathological sensory dysfunction.

   The proposed research will quantify sensory nerve sensitivity in the bladder and urethra in adult women with underactive bladder. The investigators will then amplify sensory nerve activity via continuous electrical stimulation to improve LUTS associated with underactive bladder. Achieving the proposed objectives will establish a prognostic marker for rationally guided electrical stimulation in women with underactive bladder. Understanding how these mechanisms contribute to impaired emptying in underactive bladder will enable the development of novel therapeutics to enhance quality of life.

3. Subject Recruitment: Established patients with underactive bladder will be identified by MaestroCare chart review. New patients with underactive bladder will be identified by Duke urogynecologists who see patients at one of two urogynecologic offices (Navaho Clinic in Raleigh or Patterson Place in Durham).
4. Design and Procedures: The investigators will perform a parallel interventional study with two non-randomized study arms (bladder stimulation and urethral stimulation). Potential participants will be screened remotely by email via RedCap by completing a questionnaire to determine bothersome symptoms and perceptions of bladder function. Potential participants that meet eligibility criteria will be scheduled for an in person study procedure visit, where informed consent will be signed. Participants will then undergo current perception threshold (CPT) testing, where electrical stimulation will be delivered via a catheter to the urethra (intraurethral) and bladder (intravesical) to evoke sensation. The CPT results will inform whether the participant receives an investigational session of intravesical (bladder) electrical stimulation or intraurethral electrical stimulation. Following electrical stimulation, the participant will undergo urodynamic studies (cystometrogram, pressure-flow study) to assess bladder function after the investigational stimulation procedures. The participant will also be asked to complete remotely by email a post-study symptom RedCap questionnaire 7 days after study completion.

• Study Type: Interventional
• Enrollment (Estimated): 20
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Em Abbott, PhD; Phone Number: 919-660-5299; Email: em.abbott@duke.edu

Study Locations

• United States
  • North Carolina
    • Durham, North Carolina, United States, 27707
      • Recruiting
      • Duke Medical Plaza Patterson Place
      • Contact: Em Abbott, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 16 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Females ages 18 and older
• Able to provide informed consent and agree to the study risks
• Willing to withdraw from medications affecting urination for the 48 hours prior to the procedure (e.g., alpha-adrenergic antagonists, cholinergic agonists, cholinesterase inhibitors)

• Has the below response to 2 of the 3 questions:

  1. Questions regarding self-reported poor sensation during bladder filling or emptying (one or more of the below)

     • In the past 7 days, where did the participant feel sensations when needing to urinate? Answer: "No" response for Bladder Area
     • In the past 7 days, how often did the participant have no sensation of urine flow while urinating? Answer: "Most of the time" or "Every time" response
     • In the past 7 days, how often did the participant feel that the bladder was not completely empty after urination? Answer: "Most of the time" or "Every time" response

  2. Questions regarding self-reported bothersome urinary symptoms (one or more of the below)

     • In the past 7 days, how satisfied was the participant with bladder function? Answer: "Not at all satisfied" or "Somewhat satisfied" response
     • In the past 7 days, how bothered was the participant by urinary symptoms? Answer: "Very bothered" or "Extremely bothered" response
  3. Standard uroflowmetry with a voiding efficiency (voided volume / voided volume + residual volume) of < 80%, voided volume + residual volume must be >150ml for measurement

Exclusion Criteria:

• Preexisting neurological impairment (e.g., spinal cord injury, multiple sclerosis, Guillain-Barre, cauda equina syndrome, cerebrovascular accident, Parkinson's disease, traumatic brain injury)
• Functional obstruction demonstrated by either elevated pelvic floor activity on EMG during standard pressure flow study or high tone pelvic floor on clinical exam)
• Pelvic organ prolapse beyond introitus
• Active urinary tract infection (candidate would be deferred until treated)
• Positive pregnancy test
• Less than 6 weeks postpartum
• Unevaluated hematuria
• Urethral stricture/stenosis
• Surgical obstruction i.e., urinary retention due to obstructive sling or other anti incontinence procedure
• Surgical procedures to increase bladder capacity (e.g., augmentation cystoplasty)
• Active sacral neuromodulation or ongoing posterior tibial nerve stimulation sessions
• Botulinum toxin injection in the past six months
• History of genitourinary or gastrointestinal cancer

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Intraurethral Electrical Stimulation; This procedure is specific to the urethral stimulation arm. A sterile stimulation catheter (custom, 7-French) will be placed in the urethra and positioned with the electrode contact 10-14 mm from the bladder neck to stimulate the proximal urethra. A single return electrode will also be placed on the abdominal skin above the pubic bone. Stimuli will be delivered as 0.2 ms charge-balanced biphasic rectangular current pulses. Stimulation frequency will be 2-20 Hz and amplitude will be adjusted individually to 80% of the maximum tolerable intensity. Electrical stimulation will be applied to the proximal urethra at "strong desire to void" during cystometry. The participant will then be given permission to void at "maximum cystometric capacity" with continuous intraurethral stimulation.	Device: Neurometer Neurotron CPT; All participants will undergo CPT testing. A Neurotron catheter (12-French) with electrode will be inserted through the urethra into the bladder. The catheter balloon will be inflated and positioned at the urethrovesical junction to stimulate the urethra 10-14 mm from the bladder neck. For bladder stimulation, the catheter balloon will be deflated and the catheter will be advanced into the bladder. The device will deliver sine wave stimulus pulses at 5, 250, and 2,000 Hz. CPT will be established using an automated forced choice paradigm by the method of levels. Testing order of the bladder and urethra will be randomized between participants.; Procedure: Cystometry; After bladder stimulation or during intraurethral stimulation, cystometry will be performed to assess bladder sensation and storage. A dual-chamber 8-French catheter will be passed through the urethra into the bladder for retrograde filling. A second 8-French catheter will be placed in the vagina to measure intra-abdominal pressure. A stimulation electrode catheter will only be inserted in the intraurethral stimulation arm. EMG pads will then be placed at 3 and 9 o'clock on each side of the perineum. The bladder will then be filled with room-temperature sterile saline solution in a retrograde fashion using a pump. Bladder sensation and urgency will be assessed while filling.; Procedure: Pressure-flow study; A pressure flow study will be performed to evaluate voiding function after stimulation. The transurethral and intra-vaginal catheters are left in place after cystometry and the participant will be asked to void around them, into a commode. Bladder and abdominal pressures will be recorded, as well as urine flow over time.
Experimental: Intravesical Electrical Stimulation; This procedure is specific to the bladder stimulation arm. A sterile stimulation catheter (custom, 7-French) will be placed in the bladder through the urethra and the electrode contacts will be positioned to be floating within the bladder. A single return electrode will also be placed on the abdominal skin above the pubic bone. Stimuli will be delivered as 0.2 ms charge-balanced biphasic rectangular current pulses. Stimulation frequency will be set at 20 Hz and amplitude will be adjusted individually to 80% of the maximum tolerable intensity. Electrical stimulation will be applied to bladder sensory nerves for up to 60 minutes prior to the start of urodynamic studies.	Device: Neurometer Neurotron CPT; All participants will undergo CPT testing. A Neurotron catheter (12-French) with electrode will be inserted through the urethra into the bladder. The catheter balloon will be inflated and positioned at the urethrovesical junction to stimulate the urethra 10-14 mm from the bladder neck. For bladder stimulation, the catheter balloon will be deflated and the catheter will be advanced into the bladder. The device will deliver sine wave stimulus pulses at 5, 250, and 2,000 Hz. CPT will be established using an automated forced choice paradigm by the method of levels. Testing order of the bladder and urethra will be randomized between participants.; Procedure: Cystometry; After bladder stimulation or during intraurethral stimulation, cystometry will be performed to assess bladder sensation and storage. A dual-chamber 8-French catheter will be passed through the urethra into the bladder for retrograde filling. A second 8-French catheter will be placed in the vagina to measure intra-abdominal pressure. A stimulation electrode catheter will only be inserted in the intraurethral stimulation arm. EMG pads will then be placed at 3 and 9 o'clock on each side of the perineum. The bladder will then be filled with room-temperature sterile saline solution in a retrograde fashion using a pump. Bladder sensation and urgency will be assessed while filling.; Procedure: Pressure-flow study; A pressure flow study will be performed to evaluate voiding function after stimulation. The transurethral and intra-vaginal catheters are left in place after cystometry and the participant will be asked to void around them, into a commode. Bladder and abdominal pressures will be recorded, as well as urine flow over time.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Voided Percentage	Use of intraurethral electrical stimulation or intravesical electrical stimulation to assess increase in voided percentage during pressure-flow studies. Voided percentage is calculated as voided volume divided by the sum of voided volume and residual volume.	pressure-flow study, up to 30 minutes
Change in Bothersome Symptoms and Sensation	Lower Urinary Tract Dysfunction Research Network Symptom Index-29 (LURN SI-29) to assess whether electrical stimulation decreases urinary bothersome symptoms and increases bladder sensation during filling and emptying. Scores range from 0 (least severe) to 100 (most severe). Higher scores indicate greater severity of lower urinary tract symptoms.	baseline and post study procedures, up to 30 minutes

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Current Perception Threshold	Assess bladder or urethral current perception threshold (CPT) in women with underactive bladder compared to normative values. The CPT value determined by the device is defined as the average of the minimum amplitude of the stimulus consistently detected and the stimulus 40 µA lower that was consistently not detected.	CPT, up to 30 minutes
Cystometry Volume	Use of intravesical electrical stimulation to assess volumes at cystometric endpoints relative to baseline. Bladder sensation and urgency assessed at volume of first sensation during bladder filling, first desire to void, strong desire to void, and maximum cystometric capacity.	cystometry, up to 30 minutes
Bladder Contraction Strength	Use of intraurethral electrical stimulation to assess contraction strength relative to baseline. Bladder pressure (cmH2O) is recorded over time during voiding.	pressure-flow study, up to 30 minutes
Bladder Contraction Duration	Use of intraurethral electrical stimulation to assess contraction duration relative to baseline. Bladder pressure is recorded over time (seconds) during voiding.	pressure-flow study, up to 30 minutes

Collaborators and Investigators

• Sponsor: Duke University
• Investigators: Study Chair: Cindy L Amundsen, MD, Duke University; Principal Investigator: Em Abbott, PhD, Duke University

Publications and helpful links

General Publications

• Lee WC, Wu HP, Tai TY, Yu HJ, Chiang PH. Investigation of urodynamic characteristics and bladder sensory function in the early stages of diabetic bladder dysfunction in women with type 2 diabetes. J Urol. 2009 Jan;181(1):198-203. doi: 10.1016/j.juro.2008.09.021. Epub 2008 Nov 14.
• Fowler CJ, Griffiths D, de Groat WC. The neural control of micturition. Nat Rev Neurosci. 2008 Jun;9(6):453-66. doi: 10.1038/nrn2401.
• Jung SY, Fraser MO, Ozawa H, Yokoyama O, Yoshiyama M, De Groat WC, Chancellor MB. Urethral afferent nerve activity affects the micturition reflex; implication for the relationship between stress incontinence and detrusor instability. J Urol. 1999 Jul;162(1):204-12. doi: 10.1097/00005392-199907000-00069.
• Bump RC. The urethrodetrusor facilitative reflex in women: results of urethral perfusion studies. Am J Obstet Gynecol. 2000 Apr;182(4):794-802; discussion 802-4. doi: 10.1016/s0002-9378(00)70328-0.
• Osman NI, Chapple CR, Abrams P, Dmochowski R, Haab F, Nitti V, Koelbl H, van Kerrebroeck P, Wein AJ. Detrusor underactivity and the underactive bladder: a new clinical entity? A review of current terminology, definitions, epidemiology, aetiology, and diagnosis. Eur Urol. 2014 Feb;65(2):389-98. doi: 10.1016/j.eururo.2013.10.015. Epub 2013 Oct 26.
• Jeong SJ, Kim HJ, Lee YJ, Lee JK, Lee BK, Choo YM, Oh JJ, Lee SC, Jeong CW, Yoon CY, Hong SK, Byun SS, Lee SE. Prevalence and Clinical Features of Detrusor Underactivity among Elderly with Lower Urinary Tract Symptoms: A Comparison between Men and Women. Korean J Urol. 2012 May;53(5):342-8. doi: 10.4111/kju.2012.53.5.342. Epub 2012 May 18.
• Chapple CR, Osman NI, Birder L, van Koeveringe GA, Oelke M, Nitti VW, Drake MJ, Yamaguchi O, Abrams P, Smith PP. The underactive bladder: a new clinical concept? Eur Urol. 2015 Sep;68(3):351-3. doi: 10.1016/j.eururo.2015.02.030. Epub 2015 Mar 11.
• Gammie A, Kaper M, Dorrepaal C, Kos T, Abrams P. Signs and Symptoms of Detrusor Underactivity: An Analysis of Clinical Presentation and Urodynamic Tests From a Large Group of Patients Undergoing Pressure Flow Studies. Eur Urol. 2016 Feb;69(2):361-9. doi: 10.1016/j.eururo.2015.08.014. Epub 2015 Aug 28.
• Uren AD, Cotterill N, Harding C, Hillary C, Chapple C, Klaver M, Bongaerts D, Hakimi Z, Abrams P. Qualitative Exploration of the Patient Experience of Underactive Bladder. Eur Urol. 2017 Sep;72(3):402-407. doi: 10.1016/j.eururo.2017.03.045. Epub 2017 Apr 8.
• Miyazato M, Yoshimura N, Chancellor MB. The other bladder syndrome: underactive bladder. Rev Urol. 2013;15(1):11-22.
• Ukimura O, Ushijima S, Honjo H, Iwata T, Suzuki K, Hirahara N, Okihara K, Mizutani Y, Kawauchi A, Miki T. Neuroselective current perception threshold evaluation of bladder mucosal sensory function. Eur Urol. 2004 Jan;45(1):70-6. doi: 10.1016/j.eururo.2003.08.004.
• Kenton K, Simmons J, FitzGerald MP, Lowenstein L, Brubaker L. Urethral and bladder current perception thresholds: normative data in women. J Urol. 2007 Jul;178(1):189-92; discussion 192. doi: 10.1016/j.juro.2007.03.032. Epub 2007 May 17.
• Cella D, Smith AR, Griffith JW, Flynn KE, Bradley CS, Gillespie BW, Kirkali Z, Talaty P, Jelovsek JE, Helfand BT, Weinfurt KP; LURN Study Group. A new outcome measure for LUTS: Symptoms of Lower Urinary Tract Dysfunction Research Network Symptom Index-29 (LURN SI-29) questionnaire. Neurourol Urodyn. 2019 Aug;38(6):1751-1759. doi: 10.1002/nau.24067. Epub 2019 Jun 21.
• Gladh G, Mattsson S, Lindstrom S. Intravesical electrical stimulation in the treatment of micturition dysfunction in children. Neurourol Urodyn. 2003;22(3):233-42. doi: 10.1002/nau.10078.
• Jiang CH, Lindstrom S. Optimal conditions for the long-term modulation of the micturition reflex by intravesical electrical stimulation: an experimental study in the rat. BJU Int. 1999 Mar;83(4):483-7. doi: 10.1046/j.1464-410x.1999.00947.x.
• Deng H, Liao L, Wu J, Chen G, Li X, Wang Z, Wan L. Clinical efficacy of intravesical electrical stimulation on detrusor underactivity: 8 Years of experience from a single center. Medicine (Baltimore). 2017 Sep;96(38):e8020. doi: 10.1097/MD.0000000000008020.
• Gustafson KJ, Creasey GH, Grill WM. A urethral afferent mediated excitatory bladder reflex exists in humans. Neurosci Lett. 2004 Apr 22;360(1-2):9-12. doi: 10.1016/j.neulet.2004.01.001.
• Yoo PB, Horvath EE, Amundsen CL, Webster GD, Grill WM. Multiple pudendal sensory pathways reflexly modulate bladder and urethral activity in patients with spinal cord injury. J Urol. 2011 Feb;185(2):737-43. doi: 10.1016/j.juro.2010.09.079. Epub 2010 Dec 18.

Study record dates

Study Major Dates

• Study Start (Actual): September 1, 2021
• Primary Completion (Estimated): December 31, 2024
• Study Completion (Estimated): December 31, 2024

Study Registration Dates

• First Submitted: August 13, 2020
• First Submitted That Met QC Criteria: August 15, 2020
• First Posted (Actual): August 18, 2020

Study Record Updates

• Last Update Posted (Actual): August 8, 2023
• Last Update Submitted That Met QC Criteria: August 4, 2023
• Last Verified: August 1, 2023

More Information

Terms related to this study

• Keywords: electrical stimulation; bladder; urethra; urodynamics
• Additional Relevant MeSH Terms: Urologic Diseases; Urinary Bladder Diseases; Lower Urinary Tract Symptoms; Urological Manifestations; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Male Urogenital Diseases; Urinary Bladder, Underactive
• Other Study ID Numbers: Pro00106457

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: Yes