Ultrasonic micturition cystourethroscopy

The capabilities of the ultrasound method in diagnostics of obstructive diseases of the lower urinary tract (LUT) have significantly expanded with the introduction of ultrasound micturition cystourethroscopy (UMCUS). The study is performed transrectally during urination, which allows visualizing the neck of the urinary bladder (UB), the prostate and membranous parts of the urethra. Unlike micturition X-ray cystourethrography, UMCUS makes it possible to simultaneously obtain information both on the state of the urethral lumen and on the structure of paraurethral tissues, which significantly expands the diagnostic capabilities of the method. This eliminates the need to introduce a contrast agent into the urethra and expose the patient to radiation. UMCUS allows visualizing areas of narrowing and deformation of the urethra caused by prostate adenoma. Conducting ultrasound micturition cystourethroscopy in real time with parallel video recording gives this study a functional nature.

This study evaluates the lumen of the urethra during urination, determines the relationship of the IVO with pathological changes in the prostate, areas of narrowing and deformation of the urethra from its internal opening to the bulbous section. In case of strictures of the urethra in the membranous section, the fact of narrowing itself is established, and in some cases, the echogenicity of this zone is assessed. The magnitude and nature of the change in the diameter of the urethra in different phases of urination are studied.

It should be noted that in 24.7% of cases, ultrasound micturition cystourethroscopy is uninformative. The reason for unsatisfactory results of the study is the inability to visualize the urethra, which may be due to the following factors:

• inability to urinate at the time of the examination;
• urination with a weak stream (Q _max < 4-6 ml/s);
• subvesical form of prostate growth - visualization of the neck of the bladder (vesicoprostatic segment) is difficult;
• displaced form of prostate growth without a middle lobe, which impairs visualization of the bladder neck (vesicoprostatic segment);
• deviation of the urethra in the transverse direction due to an asymmetric increase in the lateral lobes of the prostate, which complicates the visualization of the prostatic part of the urethra during sagittal scanning.

As a result of ultrasound micturition cystourethroscopy for prostate adenoma, the following data can be obtained:

• narrowing of the prostatic urethra from 0.1 to 0.4 cm due to hyperplastic tissue protruding into its lumen;
• increase in the angles of the S-shaped bend of the urethra;
• middle lobe valve effect;
• valve effect of the enlarged lateral lobes protruding into the neck of the bladder;
• valve effect of enlarged lateral lobes of the prostate protruding into the prostatic part of the urethra;
• dilation of the prostatic urethra, which is typical for a stricture that is located more distally (prestenotic dilation).

The most common cause of infravesical obstruction in patients with prostate hyperplasia, detected by ultrasound micturition cystourethroscopy, is the middle lobe, which, in the form of a valve, closes the lumen of the vesicoprostatic segment during urination. Considering the fact that this study is performed during urination, which makes it possible to evaluate the lumen of the urethra in real time, it seems extremely useful for determining the causes and level of infravesical obstruction and planning the volume of TURP.

A more complete picture of the anatomical and functional processes occurring during urination is provided by a combination of ultrasound micturition cystourethroscopy with uroflowmetry. M.A. Gazimiev, together with the staff of the Urology Clinic of the R.M. Fronshteyn MMA, developed and introduced into practice an echo-urodynamic study (EUDS) - measuring the minimum cross-section of the urethra by comparing it with the volumetric speed of urine flow and recording intra-abdominal pressure. EUDS makes it possible to estimate the calculated value of intravesical pressure mathematically, non-invasively. which is of key importance in assessing the urodynamics of the LUT.

However, the uneven narrowing of the urethral lumen in IVO creates objective difficulties in reliably establishing the degree and location of the smallest cross-section of the urethra, which increases the error in calculating intravesical pressure. Nevertheless, YG Alyaev et al. believe that the comparison of the data of EUDI and complex urodynamic study is not entirely valid due to the fact that they are based on different, practically incomparable indicators of the urination process. Despite this, the complete absence of invasion into the LUT and the complications associated with it, low time and cost costs, sufficiently high accuracy and sensitivity of the technique allow it to be used in examining patients with urination disorders. This may be especially relevant in cases where the use of traditional invasive methods of urodynamic examination is not possible for a number of reasons.

Of considerable interest in studying urination disorders is the technique of ultrasound micturition cystourethroscopy with color Doppler mapping of urine flow. The use of ultrasound micturition cystourethroscopy allowed us to compare the data on the dynamic activity of the urethra with the linear velocity of urine flow in different parts of the urethra in various diseases of the prostate and urethra. A relationship was found between the linear velocity of urine flow and the degree of urethral narrowing, which is undoubtedly of some interest. However, at the present stage of development, the technique does not allow us to judge the contractile activity of the detrusor and the degree of infravesical obstruction.