Endoscopic Assisted Procedures

During microscopic surgery, endoscopes can be used to assist microscopic vision, as in the cases described below

Tumor Facial nerve

a. Endoscope assisted removal of intrameatal acoustic nerve schwanomma

Endoscopy becomes very helpful whilst removing the meatal part of acoustic nerve schanomma. This part of the tumor is not visualized during microscopy. Blind removal may lead to facial nerve damage. With angled endoscope this tumor can be excised under direct vision.

b. Endoscopic assisted Microvascular decompression (MVD) of trigeminal nerve in case of trigeminal neuralgia.

This patient had severe unrelenting facial pain, which did not respond to usual pharmacotherapy. MVD was performed through a small retromastoid craniotomy. Endoscope is very useful during such procedures to confirm complete decompression of the trigeminal nerve.

B. Aneurysm Surgery

In microsurgery for aneurysms, the exposure could be very limited due to swollen brain. After clipping the aneurysm, occasionally endoscope could be used to confirm completeness of clipping or rule out inclusion of any normal blood vessel in the clip.

Acom aneurysm
Acom aneurysm
Acom aneurysm

In endoscope-assisted aneurysm surgery, the craniotomy, subarachnoid dissection, and cranial base osteotomy are generally performed in the usual manner. The use of the endoscope during clipping procedures includes three steps: initial inspection, clipping, and final inspection.


C.Microvascular Decompression (MVD) Procedures

Trigeminal Neuralgia

Trigeminal neuralgia is a chronic pain condition that affects the trigeminal nerve, which carries sensation from your face to your brain. If you have trigeminal neuralgia, even mild stimulation of your face, such as from brushing your teeth or putting on makeup may trigger a jolt of excruciating pain.
Trigeminal neuralgia
 (TN), also known as tic douloureux, is sometimes described as the most excruciating pain known to humanity. The pain typically involves the lower face and jaw, although sometimes it affects the area around the nose and above the eye. This intense, stabbing, electric shock-like pain is caused by irritation of the trigeminal nerve, which sends branches to the forehead, cheek and lower jaw. It usually is limited to one side of the face. The pain can be triggered by an action as routine and minor as brushing your teeth, eating or the wind. 

Blood vessel compressing Trigeminal nerve
Blood vessel compressing Trigeminal nerve

Attacks may begin mild and short, but if left untreated, trigeminal neuralgia can progressively worsen. Most patients report that their pain begins spontaneously and seemingly out of nowhere. 
A high-resolution, thin-slice or three-dimensional MRI can reveal if there is compression caused by a blood vessel. Newer scanning techniques can show if a vessel is pressing on the nerve and may even show the degree of compression.

Multiple vessels compressing the Trigeminal nerve

In the beginning, it is treated with medicines. If the medicines in effective or has side effects, surgery (microvascular decompression) needs to be considered. It involves microsurgical exposure of the trigeminal nerve root, identification of a blood vessel that may be compressing the nerve, and gentle movement of the blood vessel away from the point of compression. This surgery is done through a small opening in the skull behind the ear.

Microscopic View

Endoscopic View

Compressing blood vessel Trigeminal nerve

Endoscopic View

Trigeminal nerve decompressed Using Febrillar

C. Endoscopic Temporal Horn Fenestration

This patient had a fall from 20 feet tall chemical tank 10 years ago and had sustained subdural hematoma, which was operated. He was asymptomatic for almost 9 years, when he started complaining constant dull headache at the site of surgery. MRI brain revealed entrapped temporal horn of the lateral ventricle. The CSF pressure of the temporal horn was high. The medial wall of the temporal horn was fenestrated by endoscope, thereby communication it with the basal cisterns. He was relived of the headache completely.

Facial Hemispasm

Hemifacial spasm is a disorder in which the muscles on one side of your face twitch involuntarily. Hemifacial spasm is most often caused by a blood vessel touching or pulsating against a facial nerve. It may also be caused by a facial nerve injury or a tumor. Sometimes there is no known cause. The symptoms include twitching or contracting of muscles in the face that are usually on one side of the face. They are uncontrollable and painless.

These contractions often start in the eyelid, then may progress and affect the cheek and mouth on the same side of the face. At first, hemifacial spasms come and go. But eventually, usually, over the course of several months to a few years, they occur almost constantly.
A high-resolution, thin-slice or three-dimensional MRI can reveal if there is compression caused by a blood vessel. Newer scanning techniques can show if a vessel is pressing on the nerve.

Blood vessel compressing facial nerve /Normal facial nerve on opposite side

Schematic representation

Endoscopic view

Vein (blue) Facial nerve (pinkish white) Artery (red)

Microscopic view

During surgery (MVD), the nerve is cleared of all adhesions, and separated from offending blood vessles.