What is Cystometry?

Cystometry, also known as cystometric study, is a diagnostic test used to assess bladder pressure and function. Utilized as an investigative tool, cystometry is administered to diagnose a variety of conditions including bladder stones, prostate abnormalities, and spinal cord injuries. As with any medical procedure there are risks associated with cystometry and these should be discussed with a qualified healthcare provider prior to testing.

During cystometry, the bladder is filled with a neutral liquid or gas substance to test the bladder's pressure and contractive force during the voiding process. Once measurements inside the bladder are documented, the bladder's ability to expel the substance is recorded to aid with determining the source of the patient's urinary issues. Data recorded during the exam is plotted on a chart known as a cystometrogram (CMG) for analysis. The volume of substance administered to fill the bladder is contrasted against the accumulated pressure within the bladder as it fills. Additional data recorded during the urination process includes the duration of the voiding, amount of urine, and any delay or straining that may have occurred.

The cystometric procedure itself involves the insertion of a thin catheter outfitted with a cystometer into the bladder by way of the urethra. The catheter introduces either a saline solution or carbon dioxide gas into the bladder as the cystometer measures the bladder's inner pressure as the it fills. The time of the patient's initial awareness of the full bladder is documented along with how long it takes for him or her to experience the urge to urinate. The patient may feel a bit of discomfort with the introduction of the catheter and a strong urge to urinate as the bladder fills.

Cystoscopy is a related procedure used to diagnose conditions such as bladder stones, irritable bladder, and prostate abnormalities. As a diagnostic exam, cystoscopy employs the use of a catheter equipped with a small camera which is inserted into the bladder by way of the urethra to evaluate the condition of the bladder wall. The filling of the bladder with saline solution causes it to distend allowing for clear imaging. If abnormal tissue is discovered during the exam, a biopsy can be taken.

The entire cystometric testing process usually takes less than one hour from start to finish. Though complications associated with cystometry are rare, individuals who undergo this procedure may develop a urinary tract infection. Those who undergo a biopsy during the administration of a cystoscopy procedure are at a minor risk of experiencing excessive bleeding at the biopsy site. Rare instances of the rupturing of the bladder wall during the cystoscopy testing process have been documented.