Physiology and pathology of continence in women: theoretical and practical aspects of the problem

The article continues review of the scientific research on the fundamentals of the physiology and pathology of the continence mechanism in women. The mechanism of transmission of pulses of increased intra-abdominal pressure while straining is represented. Among the factors that maintain a positive urethral-vesical pressure gradient at the time of the actual physical stress, are the own urethral factors, periurethral supporting and retaining structures and the structures of the pelvic floor. Preservation of the positive pressure gradient at the time of physical stress is provided by synergistic interaction of the sphincter apparatus of the urethra, and all tissue structures, providing the transmission of pulses of increased abdominal pressure on the proximal urethra. Therefore, a positive result of surgical interventions for urinary incontinence, is due to the restoration of the mechanism of transmission of pulses of increased intra-abdominal pressure on urethra. The positive effect of the operation is only achieved by prosthesing the biomechanical effect of pubo-urethral ligaments, pubovesical fascia and the anterior pelvic floor and is determined by two factors - the «return» of the proximal urethra in the so-called «Zone of hydraulic protection» and successful re-establishment or replacement of its «mainstay». One of the main issues, affecting the outcomes of the operation is the reliability of fixation and preservation of floating ability of the distal part of the proximal urethra. Inadequate fixation of the urethra leads to rapid recurrence of stress urinary incontinence, while hyperfixation, prevents the involuntary leakage of urine, but often creates new problems with urination -from urinary retention to the obstructive type of urination.