Lumbar-peritoneal shunt

A lumbar-peritoneal shunt is a type of cerebral shunt.

A shunt is described as a tube, catheter or "surgically created anastomosis" and is designed to bypass or redirect bodily fluids from one point in the body to another.

Lumbar-peritoneal shunts are used in neurological disorder

Neurological disorder

A neurological disorder is a disorder of the body's nervous system. Structural, biochemical or electrical abnormalities in the brain, spinal cord, or in the nerves leading to or from them, can result in symptoms such as paralysis, muscle weakness, poor coordination, loss of sensation, seizures,...

s, in cases of chronic increased intracranial pressure to drain excess cerebrospinal fluid

Cerebrospinal fluid

Cerebrospinal fluid , Liquor cerebrospinalis, is a clear, colorless, bodily fluid, that occupies the subarachnoid space and the ventricular system around and inside the brain and spinal cord...

(CSF) from the Subarachnoid cavity

Subarachnoid space

In the central nervous system, the subarachnoid cavity is the interval between the arachnoid membrane and pia mater....

associated with such conditions as hydrocephalus

Hydrocephalus

Hydrocephalus , also known as "water in the brain," is a medical condition in which there is an abnormal accumulation of cerebrospinal fluid in the ventricles, or cavities, of the brain. This may cause increased intracranial pressure inside the skull and progressive enlargement of the head,...

and Benign intracranial hypertension (BIH) also known as idiopathic intracranial hypertension

Idiopathic intracranial hypertension

Idiopathic intracranial hypertension , sometimes called by the older names benign intracranial hypertension or pseudotumor cerebri , is a neurological disorder that is characterized by increased intracranial pressure in the absence of a tumor or other diseases...

(IIH) and pseudotumor cerebri (PTC), idiopathic intracranial hypertension is the preferred name for the condition.

There are various categories of medical shunts

Shunt (medical)

In medicine, a shunt is a hole or a small passage which moves, or allows movement of fluid from one part of the body to another. The term may describe either congenital or acquired shunts; and acquired shunts may be either biological or mechanical.* Cardiac shunts may be described as...

and there are two main categories of shunt used in the treatment of chronic increased intracranial pressure

Intracranial pressure

Intracranial pressure is the pressure inside the skull and thus in the brain tissue and cerebrospinal fluid . The body has various mechanisms by which it keeps the ICP stable, with CSF pressures varying by about 1 mmHg in normal adults through shifts in production and absorption of CSF...

due to cerebrospinal fluid (CSF), they are cerebral shunt

Cerebral shunt

Cerebral shunts are commonly used to treat hydrocephalus, the swelling of the brain due to excess buildup of cerebrospinal fluid . If left unchecked, the cerebral spinal fluid can build up leading to an increase in intracranial pressure which can lead to intracranial hematoma, cerebral edema,...

s and lumbar shunts (extracranial shunts). Below is a list of the various types of the above two categories of shunts:

Cerebral shunts:

Ventriculo-peritoneal shunt (VP shunt)
Ventriculo-atrial shunt (VA shunt)
Ventriculo-pleural shunt (VPL shunt)

Lumbar shunts:

Lumbar-peritoneal shunt (LP shunt)
Lumbar subcutaneous shunt (LS shunt)

Composition of shunts

Each of the types of shunts listed above can be composed of a tube or catheter and various types of valves, although they can just be composed of the tubing or catheter. Below is a list of valves that are used in Lumbar-peritoneal shunts (LP shunts) and Cerebral shunts (for a more detailed list of the types of valves used go to Types of valves section of the Cerebral shunt

Cerebral shunt

page):

Delta
Medium Pressure Cylindrical
Nulsen and Spitz
Anti-Siphon
Sigma

The composition of a Lumbar-peritoneal shunt is dependent on the Neurosurgeon performing the operation, there are no guidelines determining what the composition of the Lumbar-peritoneal shunt should be for different types of cases. The composition of the Lumbar-peritoneal shunt can affect how well the patient will get on with the shunt and whether or not they may need revisions in the future, although this is not the only determining factor in whether or not a revision will be necessary.

Placement of a Lumbar-peritoneal shunt

The Lumbar-peritoneal shunt is inserted between two of the vertebrae in the lumbar region of the spine into the Subarachnoid cavity

Subarachnoid space

In the central nervous system, the subarachnoid cavity is the interval between the arachnoid membrane and pia mater....

, also known as the Subarachnoid space. The Subarachnoid cavity is a spongy tissue filled cavity that surrounds the brain and spinal cord, and this is where cerebrospinal fluid (CSF) is contained. The shunt is placed under the skin and continues around the oblique muscles on one side of the body, and terminates at the peritoneal cavity

Peritoneal cavity

The peritoneal cavity is a potential space between the parietal peritoneum and visceral peritoneum, that is, the two membranes that separate the organs in the abdominal cavity from the abdominal wall...

, a cavity in the abdomen area of the body. Once in place the Lumbar-peritoneal shunt is used to drain the excess cerebrospinal fluid from the brain via the Subarachnoid cavity and transport it to the peritoneal cavity, where it is eventually absorbed by the organs and passed out of the body during urination.

The operation is performed under General anesthetic by a neurosurgeon and usually takes a couple of hours. Patients with Lumbar-peritoneal shunts are left with two scars; a vertical scar down part of the lumbar of the spine, and a horizontal scar across the upper abdomen. A Lumbar-peritoneal shunt is expected to remain in situ for the lifespan of the patient unless revisions or relocation of the shunt is required. In some cases the shunt has been removed completely, however this is very rare as it is difficult to determine when a patients condition has changed to enable them to be independent of the shunt and relapse of the condition can occur requiring the patient to undergo surgery for the placement of a shunt again.

A Lumbar subcutaneous shunt (LS shunt) differs from these types of shunt in that the cerebrospinal fluid drains into the potential space immediately under the skin. A narrow tube is inserted into the subarachnoid space in the lumbar part of the back during a lumbar puncture. It is then fed under the skin to a site where it can drain fluid, usually in the flank.

Shunt revisions

The revision of a shunt means to replace or make adjustments to all or part of the shunt, this also means that the location of the shunt may be changed therefore changing the category or type of shunt a patient has. For some patients with shunts, a revision or multiple revisions to the shunt may be required. This can be something minor, such as adjusting the setting on a valve to change the flow level through the valve to replacing a substantial length of the shunt, or even replacing the entire shunt or relocating the shunt route to a different part of the body. For example, it may be required for a patient with a Lumbar-peritoneal shunt, if multiple revisions are required or overdrainage is occurring, to have it replaced with a Ventriculo-peritoneal shunt (VP shunt).

Shunt revisions are required due to the following complications:

Over drainage
Under drainage
Infection
Blockage or obstruction

For further details on shunt complications see the Complications section of the Cerebral shunt page

Cerebral shunt

External links

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