By Sunday, the neurosurgeon had decided to go ahead and install a shunt to help drain the excess fluid from inside Nathan's brain. His head had taken a big jump in size and his eyes continued to be unfocused and sunsetting.
A shunt is a mechanical device designed to transport the excess cerebrospinal fluid (CSF) from the ventricle to another place in the body, bypassing the blockage. It is then absorbed by the body into the bloodstream just as it normally would be.
A shunt has 3 components. The first portion of the shunt is a small narrow tube called the shunt catheter. It is surgically implanted into either the left or right ventricle above where the blockage has occurred. To implant the catheter, a horseshoe-shaped flap is cut into the scalp on the top of the head. A small hole is then drilled into the skull and the catheter is then placed into the ventricle.
The catheter is then connected to a valve or "pump." The valve controls the amount of fluid to be drained from the ventricle. The pump is connected to a flexible tube that is tunneled under the skin to behind the ear, where another small horseshoe-shaped incision has been made.
The distal, or draining, end of the shunt is then tunneled under the skin down the neck and to the point where the excess CSF will drain and be absorbed by the body. The preferred absorption site is usually the abdomen. Shunt placement in the abdomen is called a ventriculoperitoneal (ven-TRICK-you-low-pair-it-toe-NEE-ul) or VP shunt. The peritoneal cavity is the area in the abdomen between the digestive organs and the abdominal wall.
The neurosurgeon wanted to go ahead with Nathan's shunt surgery on Thursday, December 13th.