Hydrocephalus is often discovered in infancy and while not all infants with hydrocephalus require surgical intervention, this determination is based on the presence of signs and symptoms of elevated intracranial pressure (ICP). Elevation in ICP can manifest as rapidly increasing or abnormally large head circumference,j a bulging fontanelle, splayed cranial sutures, apneas and bradycardias, developmental delay, or other signs of neurologic dysfunction (1). If elevated ICP is a concern, patients with hydrocephalus are often managed by surgical implantation of a ventriculoperitoneal (VP) shunt, which allows CSF to be diverted from the ventricular system of the brain to the peritoneal cavity (2, 3). VP shunts typically consist of three main components: a proximal ventricular catheter, a flow-regulating valve (programmable or nonprogrammable), and a distal peritoneal catheter (Fig. 46.1) (4).

Several types of VP shunts are available and they are implanted in the operating room by a neurosurgeon. While full-term infants with hydrocephalus can undergo VP shunting, preterm neonates are often too small to tolerate a fully functional shunt, so a temporizing device is needed. In these cases, a ventriculosubgaleal shunt (VSGS) is placed, which diverts CSF from the ventricular system into the subgaleal space of the scalp (2, 5). Alternatively, a ventricular access device with a subcutaneous reservoir can be implanted and tapped periodically (see Chapter 57). Once infants reach a sufficient weight, typically 2,000 to 2,500 g, the temporizing device can be replaced with a fully functional VP shunt if CSF diversion is still required.

Certain scenarios may preclude distal shunt insertion into the peritoneum, such as abdominal infection (necrotizing enterocolitis in infants) or a history of multiple prior abdominal surgeries with poor peritoneal fluid reabsorption. In these cases, alternative distal catheter sites can be considered, such as the right atrium of the heart, pleural cavity, and others.