Shunt for Hydrocephalus (Water in the Brain)

Taken from here

The most common surgery for the treatment of hydrocephalus (water on the brain), is the insertion of a shunt - a device that diverts fluid from the brain into the abdominal cavity where it is safely absorbed into the blood stream. Though a shunt may be inserted in infants, children and adults, the procedure is essentially the same regardless of the size of the patient.

Anatomy and Physiology

• In a normal brain there are four fluid filled spaces called ventricles (Figure 1)
  
  1. There are two large ventricles (lateral ventricles) located on either side of the brain
     
  2. Two other ventricles (the third and fourth ventricles) are placed along the midline
     
• Within the ventricles are tufts of vascular tissue called the choroid plexus. As blood flows through the choroid plexus it distills a clear watery fluid into the ventricles called cerebrospinal fluid, or CSF
  
• CSF flows from the ventricles towards the surface of the brain and returns to the blood (Figure 2)
  
  1. From the lateral ventricles the CSF flows into the centrally placed third ventricle and then through a narrow channel called the aqueduct, into the fourth ventricle
     
  2. CSF then flows over the surface of the brain in the subarachnoid space, an area between the brain and the membrane (dura) lining the inside of the skull
     
  3. The CSF then returns to the blood by passing into the large veins that drain the brain called sinuses
  

Figure 1 - Anatomy of the ventricles.

Figure 2 - CSF flows from the lateral ventricles into the third ventricle, through the aqueduct of Sylvius, to the fourth ventricle and finally over the surface of the brain to the dural sinuses where it is absorbed into the blood.

Picture taken from www.Yoursurgery.com