Urodynamics: What, When and Why?

What Is Urodynamics?

The videourodynamics (VUDS) lab at Urocenter of New York is widely considered one of the most advanced and innovative in the world.  Dr. Jerry Blaivas, one of the originators of urodynamics, has authored two definitive textbooks and has written over 200 book chapters and peer review articles on the subject. Dr. Purohit completed a fellowship with Dr. Blaivas in 2006 and between the two of them, they have performed over 25,000 video urodynamic studies. The videourodynamic study is an outpatient procedure performed at Urocenter of New York.  No preparation is necessary except for a urinalysis and culture.  No anesthesia is needed, and the results are immediately available to both physician and patient.

When Is Urodynamics Needed?

The most common reason that urodynamics (VUDs) is done is to evaluate lower urinary tract symptoms, or LUTS, but most patients with LUTS do not require VUDs because they can be treated okay without it. VUDs is needed when treatments are not working and/or in patients who are considering surgery to correct their LUTS.  Patients with neurologic conditions like multiple sclerosis, Parkinson’s disease and spinal cord injury (neurogenic bladder) may also require VUDs because of conditions like low bladder compliance (kind of like high blood pressure of the bladder) or destrusor sphincter dyssynergia (a blockage)  which may put patients at risk of kidney damage.

The lower urinary tract is made up of the bladder, the prostate (in men), the urethra and the sphincter. In men, the urethra runs through the prostate.  The bladder is analogous to a balloon that gradually expands as it fills, and the sphincter pinches the urethra closed and holds back the urine until it is time to go. Urination occurs when the bladder contracts and the sphincter relaxes open. Lower urinary tract symptoms (LUTS) are comprised of what are called “storage” and “voiding” symptoms. Storage symptoms include urinary frequency and urgency (having to rush to the bathroom), urinary incontinence (urine leakage) and night time urination (nocturia). Voiding symptoms are problems getting urine out – symptoms include urinary hesitancy (delay in getting urine flow started), weak stream, straining to urinate and urinary retention (inability to urinate at all).

Why Urodynamics?

The purpose of urodynamics is to determine the cause of LUTS. Small catheters are passed into the bladder and rectum, sphincter EMG is recorded with patch electrodes and the entire process is monitored fluoroscopically while filling the bladder with radiographic contrast.

The VUDs study is comprised of the following tests: 

  1. Uroflowmetry: Measures urine flow.
  2. Cystometry: Measures bladder pressure during filling and voiding, and bladder sensations and control are assessed.
  3. Pressure Flow Study: Measures detrusor pressure and uroflow synchronously; it is the only method by which urethral obstruction can be diagnosed with certainty.
  4. Electromyogram: This monitors the activity of the sphincter muscle. 
  5. Fluoroscopy: Depicts lower urinary tract anatomy using x-rays and dye during filling and voiding and is the only method by which the site of urethral obstruction can be diagnosed with certainty.

Possible Complications From The Test:

  1. Urinary tract infection (UTI).
  2. Painful or frequent urination that may last up to about twenty-four hours.
  3. Difficulty urinating or inability to urinate at all, and blood in the urine (hematuria).

These complications are rare, occurring in less than 5% of patients; Most of the patients who experience these complications have preexisting conditions which makes a complication much more likely to occur.

We generally treat with a prophylactic antibiotic just prior to the procedure to prevent infection. For patients with preexisting conditions that make a UTI more likely, we will let the patient know and take the necessary precautions.

For more informations on Urodynamics, call Urocenter of New York today:

Uro Center of New York
Jerry G. Blaivas, MD, FACS
445 East 77th Street
New York, NY 10075

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