What is endoscopic third ventriculostomy (ETV)? (Part 2 of 2)

View of the interior of the brain from the right lateral ventricle

In the first part of this blog, I discussed exactly what an endoscopic third ventriculostomy is, what has brought a renewed interest in the procedure, and who makes a good candidate for it. Today I will look at potential complications as well as how success is measured in patients who undergo an ETV.

IV. What are the potential complications of an ETV

Stereotactically guided endoscopy

Thanks to new technology - such as Magnetic Resonance Imaging (MRI), Stereotactically guided endoscopy (pictured at right), flexible fiber optic scopes, and improved tools for manipulation and hemostasis (stoppage of blood flow) the risks associated with an ETV have been minimized. The advent of high-resolution MRI images now allows the neurosurgeon to clearly perceive the absence of CSF through a stenosed or occluded aqueduct, while neuroendoscopic offer unprecedented views from within the ventricular system itself.

The most common complications associated with an ETV are post-procedure fever and bleeding. The fever is the result of a combination of (a) cold light source and monopolar coagulation in the confined volume of the third ventricle which elevates the temperature of the CSF and can cause a fever. Additionally, attempts to perforate the ventricular floor can lead to bleeding, as can damage to the ventricular wall or perforation of the basilar artery. Large bleeds under the third ventricle can be catastrophic, but are rare.

Short-term memory loss is yet another potential complication associated with ETV. This is due to the fact that the procedure can affect both the hypothalamus as well as areas of the mamillary body which is responsible for memory. Over time, however, the individual usually recovers from any short-term memory loss

V. Measuring success of an ETV

"Success" of an ETV is usually considered (by both patients and doctors alike) to be the avoidance of placement of a shunt in a patient who would have otherwise required one. Medical professionals would qualify the procedure as a "success" if their patient exhibits clinical evidence of normal intracranial pressure (ICP) AND structural evidence of stable or decreased ventricular size. (Emphasis added) In the case of a patient who has previously been shunted, the shunted must have either been removed or proved to be non-functional to demonstrate success.

Conversely, most doctors would consider an ETV as a failure if the patient exhibits no change in their clinical symptoms (or ventricular size) or requires the placement of a shunt within days or months of the ETV placement.

Additional information: Endoscopic third ventriculostomy