Contractility: Cuff Versus Urodynamics Testing In Males With Voiding Lower Urinary Tract Symptoms

Contractility: Cuff Versus Urodynamics Testing In Males With Voiding Lower Urinary Tract Symptoms

A number of men will experience bothersome urinary symptoms, which become more common as they age. A number of conditions can cause these symptoms, and general practitioners may refer men to their local hospital for further assessment and treatment. Symptoms can include poor flow of urine, the need to pass urine more frequently, or the sensation that the bladder is not completely emptying. This can be due to an enlargement of the prostate gland. These symptoms can also be caused when the bladder muscle is not able to contract (squeeze) as well as it previously has to empty the bladder. This is known as underactive bladder (UAB).

It is important to distinguish between the two conditions as a cause for these symptoms, to prevent side effects from unnecessary medications or operations. Currently, men would need to undergo a bladder pressure test (urodynamics). This involves inserting a catheter via the penis into the bladder, through which the bladder is filled with fluid and pressure is measured. A separate second small tube is inserted into the rectum to measure the pressure in the abdomen. The pressure changes are observed as the bladder is filled, and then urine is passed around the catheter.

A second technique for measuring bladder pressure is the use of a small inflatable cuff which is placed around the penis (penile cuff test). The bladder pressure can then be determined by inflating the cuff and interrupting the flow of urine. The bladder can be filled naturally before the test, which means a bladder catheter tube is not required. This study is designed to find out ways that the penile cuff test can be made more accurate. It will compare the cuff results to those obtained from a bladder pressure test, and will take x-ray pictures of the urinary tract during the test.

The investigators intend to refine the procedural steps of the cuff test to improve the measurement and reduce variability with pves.isv, therefore giving a more reproducible test. By improving the penile cuff test, the investigators can then go on to assess how our non-invasive measurements correlate with urodynamically derived indices of contractility, and use data from this pilot to help construct methodology of future cuff research. The current hypotheses are that; 1) accuracy of the cuff interruption pressure (pcuff.int) can be improved by modification of penile cuff test factors, 2) the number of valid inflations obtained per patient will increase with the modifications, and 3) that this non-invasive measure of contractility will correlate with pre-existing invasive indices.

The research protocol also gives the opportunity to explore correlation between commonly used symptom scores, and accuracy in the assessment of ultrasound residual urine volume measurement.

The primary objectives are therefore:

• To modify procedural steps of the penile cuff test that may reduce the previously observed variability and perform a pilot study to assess a reduction in variance
• To identify behaviour of the urethra during penile cuff inflation, by performing x-ray screening during the penile cuff test, and assess whether this is another source of inaccuracy
• To test the basic assumption of the penile cuff test that the bladder neck remains open during flow interruption

Secondary objectives of the study include the following:

• To compare non-invasive measurements from the penile cuff test against invasive indices of contractility
• To compare 2 different symptom scores for men with voiding lower urinary tract symptoms (LUTS)
• To assess accuracy and inter-observer variability of ultrasound residual measurement against a known volume.

Inclusion Criteria:

• Male aged 18 years old or over
• Referred for video urodynamics within our department
• Predominant voiding LUTS as assessed by IPSS at screening. [The total IPSS score is out of 35, with up to 15 points for storage symptoms and 20 for voiding symptoms. If voiding symptoms as a percentage of total score is higher than storage symptoms they will be included in the study].
• Capacity to understand study procedures and give informed consent
• At least 2 voided volumes on frequency volume chart (FVC) of 250 mL

Exclusion Criteria:

• Female patients
• Long term catheterisation
• Predominant storage LUTS on IPSS at screening
• Fewer than 2 voids on FVC > 250 mL
• Known pre-existing neurological cause for symptoms
• Active urinary tract infection (UTI)