Urodynamics With and Without the Use of Fluoroscopy

How to cite: Wang, Mary Y. “Urodynamics With and Without the Use of Fluoroscopy.” November 2025. Accessed Nov 2025. https://grandroundsinurology.com/urodynamics-with-and-without-the-use-of-fluoroscopy/

Mary Wang, DNP, CRNP, University of Pennsylvania, Philadelphia, Pennsylvania, provides a practical, step-by-step overview of urodynamic studies, including those with and without fluoroscopy. This overview guides when to order testing, what each component measures, and how findings inform treatment decisions for lower urinary tract symptoms.

Nurse Practitioner Wang describes urodynamic studies as interactive, invasive tests that assess storage and emptying using catheters placed in the urethra and rectum or vagina. Patients report sensations during filling, and clinicians correlate these with measured volumes and pressures. Uroflowmetry without catheters assesses rate and curve shape. Catheterized post-void residual measurement follows.

Filling cystometry quantifies first sensation, first desire, strong desire, and capacity, along with compliance, storage pressure, and detrusor overactivity. Fill rates vary based on expected capacity or pain. Pressure flow studies during voiding evaluate detrusor pressure, flow, and patterns such as normal contraction, high pressure with minimal flow in suspected benign prostatic hyperplasia obstruction, or abdominal straining with limited detrusor activity. Electromyography using surface electrodes assesses pelvic floor activity, which should relax with voiding, and can show detrusor sphincter dyssynergia in conditions such as multiple sclerosis. Urethral pressure profiles and functional lengths are obtained using a puller catheter. Valsalva leak point pressure evaluates outlet competence in stress incontinence. Detrusor leak point pressure reflects passive leakage at rest, and values at higher pressures are associated with poor compliance and an increased risk of renal deterioration.

Fluoroscopic video urodynamics adds anatomic information using diluted contrast and low radiation. Images can demonstrate vesicoureteral reflux, trabeculation, bladder diverticula, strictures, and bladder neck obstruction, and help assess bladder compliance and post-void residual volume. Concerning findings include impaired compliance, vesicoureteral reflux, extravasation, and large diverticula.

Patient education emphasizes the importance of invasive testing, regular eating, and medications before arrival, as well as the expected transient nature of dysuria or hematuria, and the limited use of antibiotic prophylaxis for high-risk patients. The presentation reviews room setup and highlights rapid response to vasovagal reactions and autonomic dysreflexia during filling.