(1)
Functional Urology Unit, Casa Madre Fortunata Toniolo, Bologna, Italy
Videourodynamic studies consist of the simultaneous measurement of multichannel urodynamic parameters with imaging (fluoroscopy) of the lower urinary tract (Fig. 10.1). The technique is the most sophisticated investigation of lower urinary tract since it provides a precise evaluation of both anatomy and function. Fluoroscopy allows direct observation of the bladder outline, the position and conformation of the bladder neck in relation to the pubic symphysis, bladder neck closure during rest and stress, and vesicoureteric reflux during filling and voiding. Most of the equipments commercially available are provided with softwares that correlate fluoroscopic images with the corresponding urodynamic parameters such that reports have the images simultaneously with the pressure tracings.
Figure 10.1
Videourodynamic setup
Videourodynamics requires the X-ray facilities and is usually performed in a radiology department. The fluid medium is radiographic contrast such as iohexol (Omnipaque), while the technique of the examination follows the same rules (setting, signal verification, etc.) of conventional urodynamics.
10.1 Procedure
UDS is performed in the usual manner and fluoroscopy is done periodically both during filling and voiding phase. Patient may be either supine on X-ray table or in a sitting position with C-arm fluoroscopic unit placed under videoUDS chair (Fig. 10.2).
Figure 10.2
Electrical bed with fluoroscopy C-arm particularly suitable for patients with neurogenic bladder (Courtesy of Sonesta Medical)
Footnote
When radiological facilities and videoUDS chair are unavailable together, conventional urodynamics and videocystouretrography (VCUG) can be done separately within a short interval.
During filling phase, X-ray intends on the bladder perpendicularly in AP direction. If reflux is suspected, some oblique views should be taken in order to visualize vesicoureteral junction.
Study done in AP position leads to superimposition of pre-prostatic urethra in male and most or all of the urethra in female depending on status of pelvic support and urethral mobility. An initial plain film should be taken to confirm the desired patient position.
During voiding phase, oblique views are preferable to visualize the status of the bladder neck in males and the whole urethra in females.
After the bladder is partially filled with radiographic contrast (usually 200 ml), a resting image is obtained. This image provides informations on bladder position at rest, bladder shape and outline, bladder neck at rest (open or closed), and other abnormalities such as reflux or bladder diverticula.
Once the rest image is acquired, a strain (Valsalva) or cough image is obtained.
During straining, bladder neck competence and any associated incontinence (abdominal leak point pressure) and the degree of bladder descent (cystocele) can be assessed.
When the bladder is filled to capacity, a voiding cystourethrogram (VCUG) is performed with previous assessment of proper signal recording. When the patient is supine on the X-ray table, he should be positioned such that a lateral image is obtained.
During voiding phase, appropriate bladder neck and external sphincter relaxation and whole urethral outline are observed. Finally, a post-void image is obtained to determine bladder emptying.
Footnote
When post-void residual is not a concern, this image may be omitted to reduce radiation exposure. Post-void residual can be accurately calculated from the volume of contrast instilled and the volume voided.
10.2 Indications for the Addition of Video to Conventional Urodynamics
In a broader context, VUDS has been advocated in situations in which UDS alone fails to provide sufficient diagnostic information to guide therapy, especially in patients with complex or recurrent problems and patients with LUTD and relevant neurological disease (NLUTD).
Recently, there has been a reappraisal of the role of VUDS particularly in nonneurogenic LUTD.
Most of scientific societies acknowledge the role of VUDS in neurogenic bladder.
In patients with spinal dysraphism (SD) or spinal cord injury (SCI), the level of the lesion is not always predictive for urinary dysfunction, in particular in patients with incomplete lesions.
VUDS may add information with the premise of improving management and follow-up.
However, there is only low-grade evidence for the added value of VUDS in nonneurogenic LUTD. Some studies in nonneurogenic LUTS suggest a benefit of the added video, but objective outcome analyses based on image-guided management are lacking. Published evidence fails to determine the roles of the visual information “versus” the UDS information gained at VUDS.
Classically, indications for VUDS include:
Neurogenic bladder
Female SUI
BOO in females
PBNO in young males
Neurogenic bladder (NGB)
10.2.1 Tailoring VUDS for Neurogenic Patients
Many patients with NGB have significant limitations in their mobility that do not allow them to sit in the urodynamic bed like a typical patient. In addition, since many patients do not void usually into a toilet, it is acceptable for neurogenic patients to be in the supine position for urodynamic testing.
When performing videourodynamics, it is ideal for the patient to be placed in oblique position to allow a better visualization of the bladder neck. With patient in supine position, voiding recording may be a problem. A wide-bore drain pipe with appropriate length to reach the flowmeter may be necessary.
10.2.1.1 Filling Phase
Filling phase should assess the presence of vesicoureteral reflux and the compliance of the bladder.
Footnote
When reflux occurs at low volume, it may go unnoticed without the use of fluoroscopy.
A “Christmas tree” appearance with severe trabeculations is often associated with high filling pressure (>40 cm H2O), poor compliance (<30–40 ml/cmH2O), and high detrusor leak point pressure (>40 cmH2O) that are signs of “unsafe bladder” prone to upper tract damage (Fig. 10.3).
