Urodynamic studies

Urodynamic studies are classified as the main methods of functional diagnostics in urology. Their theoretical basis is the principles and laws of hydrodynamics. Registration and calculation of research parameters are based on this section of physics. It is generally accepted that the movement of urine (urodynamics) in the human body corresponds in many respects to the characteristics of fluid motion along the various reservoirs connected to each other. These include the cavity structures of the kidneys, ureters, bladder and urethra. The physical characteristics of urine movement are calculated taking into account the fact that it is a mobile, changing biological system whose imbalance in pathological changes can manifest itself with various symptoms and a corresponding clinical picture. In this regard, the term "urodynamics" is often combined with the definition of "clinical".

The main goals of clinical urodynamics

• the reproduction of the situation with symptoms of urination disorder;
• registration in a convenient graphic and / or digital form of the objective characteristics of urodynamics;
• identification of reproduced pathological characteristics, thereby providing a pathophysiological basis for the symptoms;
• obtaining information for assessing the features of the course of the disease and the effectiveness of treatment.

The demand for urodynamic studies can be explained by the following paradox: "Knowing the type of urodynamic disorder it is easy to identify the symptoms that correspond to it. To determine the clinical situation in reverse order - by the symptom to understand the type of urodynamic disorder - it is often extremely difficult. " Symptoms are deceptive and ambiguous. Their incorrect interpretation leads to unsatisfactory results of treatment. For example, with the symptom of difficult urination, it is difficult to judge what has disrupted urodynamics: obstruction of the bladder neck, obstruction at the level of the external sphincter or weak detrusor contractility? Only urodynamic studies can answer this question. In this sense, urodynamics is often compared with electrocardiography (ECG), without which it is practically impossible to determine the type of cardiac disturbance and register it in a reproducible form. The possibility of repeating the studies allows you to compare the indicators and evaluate the effectiveness of treatment (conservative or operational).

The need for the objectivization of symptoms associated with urinary symptoms arose long ago. The history of attempts to study the urodynamics of the lower urinary tracts based on knowledge of hydrodynamics begins in the mid-1950s. XX century .. When Von Garrelts described a simple device for measuring the flow of urine in time. Later on Enhorning. Smith. Claridge studied the possibility of measuring intravesical pressure and urethral resistance with pressure sensors. In 1970, Warwick and Whiteside proposed to compare urodynamic studies with radiological studies, and Thomas supplemented them with electromyography (EMG) of the pelvic floor. The first publication on the standardization of the terminology of urodynamics belongs to Bates et al. (1976). A significant contribution to the development of urodynamic research was made by N.A. Lopatkin. E.B. Mazo. A.G. Pugachev. E.L. Vishnevsky and many others.

Further improvement of urodynamic technologies was facilitated by computerization, which helped to create databases, to standardize the studies in detail, and led to the maximum reproducibility of urodynamic studies.

According to various signs, urodynamic studies are distinguished:

• upper and lower urinary tract (by level);
• adults and children (by age of patients);
• men and women (by sex);
• mandatory and optional (in place in the algorithm of examination for a particular disease);
• invasive and non-invasive (if necessary, catheterization of the urinary tract and without it);
• stationary and out-patient (in the place of holding);
• simple and combined (by the number of channels of measurement and combination with other methods).

Urodynamic studies consist of components, each of which is a complete and independent diagnostic unit.

• Uroflowmetry (UFM).
• Cystometry filling.
• Empty flow cystometry (pressure / flow ratio study).
• Examination of the function of the urethra ( profilometrija intraurethral pressure).
• EMG. Carried out in combination with UFM and cystometry.
• Video-dynamic study (a combination of urodynamic and x-ray examination, less often - ultrasound).
• Outpatient monitoring.
• Neurophysiological tests (as a supplement).

Depending on the indications, from the list of studies choose the necessary. The scope of research is determined by a specialist in urodynamic research, in most cases during the preliminary consultation less often - in the process of the study itself.

In the classical form, the conclusion of the urodynamic study consists of a graphical display of the indices of each of the components, digital characteristics, written opinion of the specialist.