Generality
A urodynamic examination is a diagnostic test that studies and evaluates the functionality of the bladder and urethra, during the respective tasks of storage (bladder) and release (urethra) of urine.
There are different types of urodynamic examination; among the most important types, we note: uroflowmetry, cystometry, bladder electromyography, post-voiding residual measurement, pressure / flow study, urethral pressure profilometry and video-urodynamic examination.
Brief anatomical reference of the urinary tract
The elements that make up the urinary tract are the kidneys and the urinary tract .
The kidneys are the main organs of the excretory system. In number of two, they reside in the abdominal cavity, on the sides of the last thoracic vertebrae and of the first lumbar vertebrae; they are symmetrical and have a shape reminiscent of a bean.
The urinary tract, instead, form the so-called urinary tract and have the following structures:
- The ureters . In number of two, it is the ducts that connect the kidneys to the bladder. For the avoidance of doubt, it is specified that each ureter is independent of the other.
- The bladder . It is a small hollow muscular organ, which accumulates urine before urination.
- The urethra . It is the duct that connects the bladder to the outside, allowing the urine to escape during the act of urination.
What is the urodynamic exam?
Urodynamic examination is the name that doctors assign to each diagnostic test, which allows to evaluate how bladder and urethra are performing their respective tasks of storage (bladder) and release (urethra) of urine.
Where does it take place and who does urodynamic examination?
A urodynamic examination can take place in hospital departments of Urology, Gynecology-Obstetrics, Internal Medicine and Primary Care.
In most cases, the medical figure who prescribes and performs urodynamic tests is the urologist .
The urologist is the medical internist specialized in the diagnosis and treatment of diseases affecting the urinary tract of men and women, and the reproductive organs of the male genus (penis, prostate, testes and seminal vesicles).
Indications
In general, doctors prescribe a urodynamic test in the presence of one of the following symptoms or conditions:
- Incontinence;
- Frequent urination;
- Urgent urge to urinate, but not followed by urination;
- Painful urination;
- Difficulty in initiating urination;
- Difficulty of complete emptying of the bladder;
- Recurrent urinary tract infections.
Purpose of urodynamic examination
The purpose of a urodynamic examination is to provide the physician with information useful for diagnosing the causes and nature of the symptoms and conditions mentioned above, so as to be able to plan, at a later date, the most appropriate therapy.
Features
There are different types of urodynamic examination; Among the most important types of urodynamic examination are:
- The uroflowmetry;
- Cystometry;
- Bladder electromyography;
- Post-voiding residual measurement;
- The pressure / flow study;
- The profilometry of urethral pressure;
- The video-urodynamic exam.
A doctor may decide to subject the same patient to one or more of the aforementioned urodynamic tests.
The choice of which and how many urodynamic tests to prescribe depends on the symptoms and health conditions that emerged during a previous physical examination. This means, for example, that in such circumstances it could be sufficient to perform only uroflowmetry, while on other occasions it could be necessary to perform combined uroflowmetry, cystometry and measurement of the post-voiding residue.
uroflowmetry
The uroflowmetry is the urodynamic exam that allows to study and evaluate, in an absolutely non-invasive way, the characteristics (speed in primis) of urinary flow, during urination.
Considered the simplest of the urodynamic tests, uroflowmetry involves the use of a device - the so-called uroflowmeter - which has the ability to measure the amount of urine emitted per unit of time, reporting it in real time on a graph.
For patients, uroflowmetry consists only in urinating in a special funnel or in a special toilet, which are in turn connected to the uroflowmeter and equipped with a special scale for measuring the flow of urine.
cystometry
Briefly, cystometry is the urodynamic test by which doctors measure:
- The total amount of urine that can contain the bladder;
- Intravesical pressure, ie the pressure inside the bladder;
- The contractile force of the bladder at the time of urination;
- The ways in which the bladder accumulates urine;
- The filling level of the bladder that induces urge to urination;
- Intravesical pressure, at the time of a sudden loss of urine.
Bladder electromyography
Electromyography is a diagnostic test, aimed at assessing the health of the muscles and cells that control the latter: the so-called motoneurons .
Bladder electromyography consists of measuring and studying the electrical activity of which the nerves, which control the bladder muscles, in particular sphincters, are the protagonists.
A particularly studied area of the bladder, during an electromyography, is the so-called bladder neck or bladder neck.
If from an electromyography of the bladder anomalous results emerge, it means that, very probably, the symptomatology in progress - the one that pushed the doctor to prescribe electromyography - is due to a nerve and / or muscular damage.
From a purely operational point of view, if the sensors for measuring the activity of the motor neurons are positioned on the skin (therefore outside), no type of anesthesia is provided; if, instead, the sensors are placed inside the body, through an urethral or rectal catheter, local anesthesia is provided.
Post-voiding residual measurement
The so-called post-voiding residual measurement (or RPM ) is the urodynamic test that measures how much urine remains inside the bladder after urination.
There are two ways to measure RPM: through an ultrasound of the bladder or through a bladder catheter .
The measurement by ultrasound of the bladder is a method of simple execution, not at all invasive and that does not require the use of anesthesia; it usually takes place in the Radiology department of hospitals and it is up to a radiologist.
Measurement using a bladder catheter, on the other hand, is a decidedly more complex and invasive method, as it involves local anesthesia and, above all, the annoying practice of inserting the catheter into the bladder, through the urethra.
Clearly, if the two measurement methods guaranteed the same results, doctors would always opt for post-voiding residual measurement by ultrasound, because it is simple and non-invasive. However, as can be inferred from the previous statement, there is an advantage in using the bladder catheter: in fact, through the bladder catheter, the doctor can empty the urine bladder and quantify it; this operation is completely impossible with bladder ultrasound.
The ability to accurately quantify the remaining urine provides precise information regarding the ability to empty the bladder.
If the residue of urine is equal to 100 milliliters, it means that the bladder empties with extreme difficulty.
Pressure / flow study
The study of pressure / flow is the urodynamic test that measures:
- Intravesical and intra-abdominal pressures, necessary for urination, e
- The flow rate of urine, through the urethra.
Test generally complementary to cystometry, the study of pressure / flow involves the use of a special pressure gauge and requires local anesthesia.
Regarding the results, abnormal circumstances are considered: low intravesical and intra-abdominal pressure values, associated with reduced urine flow, and high intravesical and intra-abdominal pressure values, associated with normal urine flow.
Urethral pressure profilometry
The urethral pressure profilometry is the urodynamic exam that allows to measure the pressure in the urethra at rest and its variations.
For the measurement of internal pressure values in the urethra, doctors use a urethral catheter, to which is connected a pressure detector - the so-called transducer - and a special physiological solution.
Measurement of urethral pressure and its variations is useful to understand the functionality of the urethra.
Video-urodynamic examination
The video-urodynamic examination is the urodynamic exam that allows you to take photographs and film the filling and emptying phases of the bladder with video.
Being able to rely on photographs and videos of the bladder, when the latter is filled and emptied, is of enormous help in identifying any problems.
There are two possible ways of performing the video-urodynamic exam: through X-rays or through an ultrasound device.
The use of X-rays requires the use of a contrast agent and the presence of the latter inside the bladder. The use of the ultrasound device, on the other hand, involves filling the bladder with hot water, through a special catheter.
Both modes of operation are to be considered moderately invasive: the first, for the use of X-rays and contrast media, while the second, for the introduction of the catheter to the bladder and the practice of local anesthesia.
Video-urodynamic X-ray and contrast imaging is also known as bladder fluoroscopy or bladder fluoroscopy .
Preparation
Each urodynamic exam has its own specific preparation, which the doctor illustrates to the patient in time, before the execution. For some types of urodynamic examination, this specific preparation is very simple; for others, however, it is more complex.
That being said, there are some general preparatory rules, which apply to any urodynamic examination. Specifically, these general preparatory rules are:
- Stop, at least 7 days before performing a urodynamic test, any medication based on medicines that, in some way, affect bladder function. The purpose of this rule is not to distort the results of the test or tests required.
- Introduce yourself, on the day the urodynamic test or test is performed, with full bladder.
For people who find it difficult to observe the aforementioned rule, doctors advise arriving at the hospital in advance and, there, taking a simple drink (water), so as to fill the bladder.
Post-procedural phase
After a urodynamic examination, it is quite common for the patient to feel burning or unwell at the time of urination. Generally, this sensation lasts for up to 24 hours.
More rarely, the patient may also suffer from hematuria (or blood in the urine ); as in the previous case, this disorder does not last more than a day after the conclusion of the diagnostic test.
risks
Most urodynamic examinations are safe.
However, it is good to remind readers that, where urethral or bladder catheters are to be used, there is a remote possibility of urinary tract infection .
The typical symptoms and signs of a urinary tract infection are:
- Stimulation to urinate stronger than normal;
- Foul-smelling urine;
- Prolonged presence of blood in the urine;
- Need to urinate often and during the night;
- Burning urination;
- Pain in the kidneys and back;
- Temperature.
How to minimize the risk of infection after a urodynamic examination
To minimize the risk of infection after a urodynamic examination with a urethral or bladder catheter, doctors advise taking plenty of water, avoiding beverages such as tea or coffee and, finally, making sure to completely empty the bladder (having patience when you is at the toilet).
Contraindications
The only urodynamic examination that presents a noteworthy contraindication is the video-urodynamic examination which involves the use of X-rays.
For the latter, the contraindication in question is pregnancy, as - as is well known - X-rays represent a danger to the developing fetus.
Results
For some types of urodynamic examination (uroflowmetry and cystometry), the results are available immediately after the test in question; for other types, instead, the results are ready only after a few days.
Normally, after each abnormal urodynamic examination, a doctor-patient meeting is scheduled to discuss the most appropriate therapy.
