Detrusor-sphincter dyssynergia

Sphincter-detrusor dyssynergia

The absence of synchronous, coordinated contraction of the muscle that expels urine from the bladder (detrusor) and relaxation of the sphincter that holds urine in the bladder is called detrusor-sphincter dyssynergia (DSD).

A patient with DSD has problems starting urination – in a typical case, immediately after the initiation of voiding, the resistance in the urethra increases significantly, and the outflow of urine becomes significantly more difficult. To empty the bladder, the patient has to strain and change position. The duration of urination time increases significantly.

Detrusor-sphincter dyssynergia is a condition in which there is a simultaneous contraction of the detrusor and striated urethral sphincter. Normally, at the moment of contraction of the bladder, the external and internal urethral sphincter relaxes. In some forms of disturbance of the innervation of the bladder (reflex spinal bladder), synchronous contraction of the bladder and relaxation of the sphincters does not occur; as a result, the person experiences difficulty urinating, and the stream of urine may be intermittent. This leads to an increase in intravesical pressure and the appearance of residual urine.

Depending on the nature of the contraction of the urethral sphincter, three types of sphincter-detrusor dyssynergia are distinguished:

• Type 1 – characterized by a gradual increase in the tone of the external urethral sphincter synchronously with an increase in the tone of the detrusor (bladder). After intravesical pressure decreases, sphincter tone also decreases. In patients with this type of dyssynergia, urination occurs only after the pressure in the bladder decreases.
• Type 2 – characterized by convulsive, chaotic contractions of the external urethral sphincter throughout the act of urination (contraction of the bladder). Urination in such patients is intermittent.

• Type 3 – the degree of contraction of the external urethral sphincter corresponds to the degree of contraction of the bladder. In such patients, urination is difficult throughout or does not occur at all.

A wrinkled bladder is a violation of innervation (neurogenic bladder), chronic inflammatory processes (cystitis) lead to the development of dystrophic and sclerotic processes in the wall of the bladder. As a result, the volume of the bladder decreases. In addition, the development of a sclerotic process in the area of the vesical triangle can lead to disruption of the outflow of urine from the kidneys due to stenosis of the ureteric orifices.

Impaired urodynamics contributes to the development of complications: hydronephrosis, pyelonephritis, kidney stones, chronic renal failure.

The diagnostic algorithm for detrusor-sphincter dyssynergia includes: a general urine test, urine culture for sterility with an antibiogram, filling out specialized questionnaires, ultrasound examination of the bladder with determination of the volume of residual urine and a comprehensive urodynamic examination.

A1-blockers are used for treatment. Drugs in this group block the transmission of impulses from the sympathetic nervous system to a1 receptors located in the neck of the bladder. As a result, smooth muscle relaxes, the tone of the vascular wall increases and blood flow in the detrusor is normalized.
Central muscle relaxants are used to a lesser extent. They reduce the activity of motor neurons and inhibit the transmission of nerve impulses in the spinal cord, resulting in reduced spasticity of striated muscles. However, the drugs do not have organ specificity, and the main side effect is severe weakness of the muscles of the limbs, which significantly limits their use.

One of the methods of treating detrusor-sphincter dyssynergia is tibial neuromodulation. See treatment of urge urinary incontinence.

Surgical methods include the injection of botulinum toxin (BOTOX, Dysport, BTHA) into the striated urethral sphincter. The mechanism of action of botulinum toxin is to block the release of the contractile mediator (acetylcholine). As a result, the impulse causing the spasm is interrupted and does not reach the muscle. The result of using botulinum toxin is relaxation of muscle structures. With detrusor-sphincter dyssynergia, the detrusor contracts, while the striated urethral sphincter remains relaxed.

Both the very nature of the pathology of detrusor-sphincter dyssynergia and its diagnosis and treatment is a non-trivial task, requiring special knowledge, high-quality diagnostics and specialized equipment, interdisciplinary integration and full-fledged doctor-patient contact. We have similar experience and skills and will be happy to help you with this problem.