External ventricular drainage
External ventricular drainage or ventriculostomy is a common neurosurgical technique and accurate placement of the intraventricular catheter is one of the most important variables in the longevity of shunt survival 1) 2).
Ventriculostomy is a neurosurgical procedure that involves creating a hole (stoma) within a cerebral ventricle for drainage. It is done by surgically penetrating the skull, dura mater, and brain such that the ventricle of the brain is accessed. When catheter drainage is temporary, it is commonly referred to as an external ventricular drain, or EVD.
When catheter drainage is permanent, it is usually referred to as a shunt. There are many catheter-based ventricular shunts that are named for where they terminate, for example, a ventriculoperitoneal shunt terminates in the peritoneal cavity, a ventriculoatrial shunt terminates within the atrium of the heart, etc. The most common entry point on the skull is called Kocher's point, which is measured 11 cm posterior to the nasion and 3 cm lateral to the midline. EVD ventriculostomy is done primarily to monitor the intracranial pressure as well as to drain cerebrospinal fluid (“CSF”), primarily, or blood to relieve pressure from the central nervous system (CNS).
Strictly speaking, “ventriculostomy” does not require the use of tubing. For example, a “third ventriculostomy” is a neurosurgical procedure that creates a hole in the floor of the third ventricle and usually has no indwelling objects.
Other types ventriculostomy include ventriculocisternostomy developed by the Norwegian doctor Arne Torkildsen.
Ventriculostomy is one of the most common emergency based neurosurgical procedures practitioners undertake globally.
On 15th October 1744, the French surgeon Claude-Nicolas Le Cat (1700-1768) introduced a specially invented cannula into the lateral ventricle of a newborn boy with hydrocephalus. The cannula was used as a tap and was left in place for 5 days, until the death of the child. This procedure should be seen as the first documented description of a device for repeated ventricular taps in the treatment of hydrocephalus. 3).
Ingraham later advocated the application of a closed draining system to minimize the infective complications 4).
Indications
Types
Plain catheter
Antibiotic impregnated catheter: Bactiseal.
Bolt-connected external ventricular drainage.
Ventriculostomy entry sites are commonly selected by freehand estimation of Kocher's point or approximations from skull landmarks and a trajectory toward the ipsilateral frontal horn of the lateral ventricles.
Endoscopic third ventriculostomy.
Tunneled external ventricular drainage.
Standard external ventricular drainage.
Long-tunneled external ventricular drainage
Guidelines
The Infectious Diseases Society of America (IDSA), the Neurocritical Care Society (NCS), and The Society for Neuroscience in Anesthesiology & Critical Care (SNACC) have published recommendations for the management of EVD-Associated Ventriculitis. The objective of this study was to assess the methodological quality and reporting clarity of these recommendations using the AGREE-II tool. We found that the overall quality of the published clinical practice guidelines is acceptable. However, continuous updates and external validation should be implemented 5)
Management
Placement
Trials
A study design of a single center, prospective, randomized controlled trial to investigate whether guided ventriculostomy is superior to the standard freehand technique. One strength of this study is the prospective, randomized, interventional type of study testing a new easy-to-handle guided versus freehand ventricular catheter placement. A second strength of this study is that the power calculation is based on catheter accuracy using an available grading system for catheter tip location, and is calculated with the use of recent study results of our own population, supported by data from prominent studies 6).