Therapy / Surgery methods

Despite numerous attempts to find therapeutic alternatives to valve implantation (e.g. through medical treatment or minimally invasive surgery), there are currently no other solutions besides the implantation of a drainage system, also called a shunt system. In general, the operation is neither risky nor difficult and is about one hour in duration. The implantation requires general anaesthesia. The drainage system consists of catheters that drain off the cerebrospinal fluid and a valve that regulates intracranial pressure. Three types of drainage can be implemented: ventricular-atrial (from the head to the right atrium of the heart), ventricular-peritoneal (from the head to the abdominal cavity) and lumbar-peritoneal (from the spinal canal to the abdominal cavity). 

1. ventricular-atrial drainage
2. ventricular-peritoneal drainage
3. lumbar-peritoneal drainage

The neurosurgeon places the valve and the catheter subcutaneously. Therefore only several small incisions to the skin are necessary. The surgeon slides the catheter under the dermal tissue and the valve is placed either on the skull behind the ear, in the thorax area or in the lumbar area.

In order to place the ventricular catheter inside one of the lateral ventricles, the neurosurgeon bores a hole through the skullcap and inserts the catheter into the ventricles. If not preset, the ventricular catheter has to be connected to the valve. The ventricular catheter is designed to drain the CSF away from the ventricles to the valve. Connected to the other side of the valve is the distal catheter, which transports CSF into either the peritoneal cavity or one of the jugular veins leading to the right atrium of the heart.

Physical background

Healthy individuals possess a positive (slightly above 0) ventricular pressure in the horizontal position. In the upright position the ventricular pressure is negative (slightly below 0).

In instances of hydrocephalus, the ventricular pressure is always increased, regardless of body position. Therefore the ventricles are enlarged.

Since the ventricles are enlarged, it is necessary to lower the intracranial pressure and maintain this within normal limits. This should be achieved independently of body position and at the same time, any risk of overdrainage should be avoided. As a consequence it is important to implant a valve that offers a significantly higher opening pressure in the vertical position (corresponding to the distance between the brain and the abdomen) than in the horizontal position. MIETHKE's range of gravitational valves function in a posture-dependent fashion, so optimal CSF drainage is maintained for every individual situation.

 

Ventricular drainage with MIETHKE gravitational valve,
Horizontal position

Ventricular drainage with MIETHKE gravitational valve,
Vertical position

Post-operative complications

As with any surgical intervention, there is a risk of infection. Complications can occur whether directly or indirectly related to the implanted valve system. Such complications include blockages of the drainage system or unexpected overdrainage.

Post-operative behaviour

Generally speaking, patients with shunt implants are not restricted in everyday activities. However patients should abstain from major physical exertion (e.g. hard physical work, strenuous sports) and should avoid impact or applying pressure to the valve or its catheters. Hydrocephalus patients who experience headache, dizziness, unnatural gait or similar symptoms should consult a physician immediately. In addition, we recommend medical check-ups at regular intervals. All MIETHKE valves have been designed to be resistant against the effects of magnetic fields.