Neuroendoscopy

BRAIN TUMORS

Series 1.

Craniopharyngioma

This is an enhanced MRI of a tumour called a craniopharyngioma. It is a tumour more commonly found in children. The best treatment is controversial, but most believe radical surgical removal is the only chance of cure.

Previously, tumours such as this craniopharyngioma, required very large incisions and skull openings in order for the tumour to be removed. Most tumours in this area can be removed just as easily through an eyebrow incision and a very small craniotomy. This is an example of “minimally invasive neurosurgery”. Endoscopic guidance is essential.

The incision can be extended laterally but is usually confined to the eyebrow only.

The skin incision tries to preserve the sensory nerves to the forehead.

The bony landmarks must be identified before taking out the window of bone.

The orbital rim can be preserved or taken.

An excellent view of the anatomy can be achieved through this limited exposure.

The goal of surgery is total removal of tumour.

The closure is equally important as the opening.

The cosmetic result is very pleasing and is barely noticeable after 3 months.

Series 2.

Colloid Cyst

This is an MRI of a colloid cyst. This tumour is rare and grows from the third ventricle where if often obstructs the normal flow of spinal fluid. This can result in headache, memory disturbance and even sudden death. Previously, patients undergoing surgery for this particular tumour required a very extensive operation, that sometimes meant splitting the 2 halves of the brain, taking hours and needing 5 to 10 days of recovery, sometimes experiencing memory problems from the surgery, or terrible seizures.

Using minimally invasive endoscopic techniques, these tumours can be removed through a burr hole, the operation taking only 20 minutes in some cases, requiring only 24 to 48 hours recovery and with fewer side effects. Of course, complications can occur even with these techniques, but they appear to be less frequent and less severe.

Once again, endoscopy is an essential tool in these minimally invasive operations.

Series 3.

Posterior Third Ventricular Tumours

Dr Teo has co-authored a paper entitled “Endoscopic management of hydrocephalus secondary to tumors of the posterior third ventricle.”

Series 1.

Low Grade Glioma

This particular tumour was a low grade glioma that was deep within the brain. Nevertheless, it was removed through a burr hole type incision and the postoperative scan showed no residual disease.

At the CMIN most craniotomies are performed by shaving very little hair, through very small openings and with minimal tissue trauma.

Brain tumours can be primary, like this one, or secondary. They can grow from the brain itself, like this one, or other structures within the cranium or skull. Sometimes their borders are obvious, but unfortunately, often they are not readily distinguishable from the normal brain.

Series 2.

Primary Meningioma

Unfortunately, there are some tumours that cannot be removed through a limited opening. Indeed, at the CMIN, although a minimally invasive approach is encouraged, surgery needs to be maximally effective. This particular tumour is a meningioma, which grows from the lining of the brain. For best results, the lining from which they arise needs to be removed along with the tumour, hence the need to expose the entire origin of the tumour.

This surgery obviously requires a large incision and an equally large skull opening.

This post-op scan shows the meningioma completely removed. This particular patient had temporary weakness of both legs but within 3 months had made a complete recovery.

Series 3.

Malignant Glioma

This is the pre-op scan of a 64 year old man who had a malignant glioma partially removed. He was not able to tolerate the postoperative radiotherapy because of raised pressure within his head and was therefore given palliative treatment only. He then approached The Centre asking for a second opinion and was offered radical resection.

After a minimally invasive craniotomy and radical resection he tolerated radiotherapy and is now alive and free of recurrence 18 months after treatment. There were no operative complications.

This is the post-op scan 14 months after his surgery at the Centre.

Series 4.

Pituitary Adenoma

This patient presented with visual deterioration from pressure of the tumour on the overlying visual pathways (optic chiasm).

This is the MRI of the same patient after removal of the tumour. The patient was discharged from hospital the day after surgery with no complications and no post-operative pain or discomfort.

Series 5.

Acoustic Neuroma

This is the scan of a 30 year old surgeon who presented with unilateral hearing loss.

This is the same patient’s scan after total resection of the tumour. He was discharged from hospital 3 days after surgery and had NO facial nerve weakness. He returned to full-time work 2 weeks later.

Series 6.

Tumours of the Third Ventricle

The third ventricle is that part of the brain that lies almost exactly in the middle of the brain. It is part of the ventricular system which contains cerebrospinal fluid (CSF) and is part of an intricate system of fluid channels. Blockage of these channels causes an excessive build-up of fluid called hydrocephalus. The most common tumour that occurs within the third ventricle is a colloid cyst. The management of these benign tumours is controversial when they present as incidental findings, but when they cause obstruction of the CSF, most neurosurgeons would recommend removal either endoscopically or open. The difference between these 2 techniques is quite impressive. When performed endoscopically, patients require a small incision, minimal brain trauma, less post-operative pain and discomfort and less complications. Unfortunately, the endoscopic technique is not always applicable.

Other tumours of the third ventricle are juvenile pilocytic astrocytomas, central neurocytomas, germ cell tumours, craniopharyngiomas and other more malignant gliomas. A specific and rare tumour that arises from the walls of the third ventricle is the HYPOTHALAMIC GLIOMA. This is a slow growing, sometimes non-growing (hamartoma) tumour that causes very unique symptoms. One of these is GELASTIC SEIZURES which cause the patient to break into spontaneous laughter. Other symptoms are obesity from loss of satiety, premature onset of puberty in young children, spontaneous rage attacks and excessive tiredness. In the past, treatment options were limited. However, through ground breaking surgery pioneered by Prof Jeff Rosenfeld in Melbourne, Australia and modified by Prof Hal Rekate in Phoenix, Arizona, patients with hypothalamic gliomas can be offered some hope with partial surgical resection of these tumours through a minimally invasive endoscopic operation.

Given the location of the third ventricle, the open approach is very difficult and may cause many side-effects. These include, but are not confined to, seizures, paralysis, degrees of loss of memory, coma, and hormone imbalance. When done endoscopically, these complications may still occur but are less likely. The long-term results of surgery have yet to be published. This procedure is new and only time and honest reporting will tell if it is a permanent cure or only a temporary reprieve.

The figures below are some examples of third ventricular tumours before and after surgery….

Small third vent tumour pre-op. This scan shows a small third ventricular tumour. Although the appearance is similar to a colloid cyst, pathology proved it was a ganglioglioma .

Large third vent tumour post-op. This scan shows the tumour was completely removed. Analysis of the tumour demonstrated a low grade astrocytoma. Although the tumour could not be removed through endoscopic techniques, the principles of minimally invasive surgery were applied and the patient still left the hospital 1 day after surgery in excellent condition and without complications.

Large third vent tumour pre-op. This scan shows a tumour in the third ventricle of considerable size. It was called “inoperable” by previous surgeons.

Small third vent tumour post-op. This scan shows the tumour has been totally removed. It was done through an endoscopic approach and the patient was discharged from hospital 1 day after surgery in a perfect neurological state

Series 7.

Brainstem tumours

The brainstem is considered the most eloquent of all parts of the brain…that means that it is arguably the most sensitive and therefore most likely to result in serious complications when surgically manipulated. It is so sensitive that many surgeons consider tumours that arise from or compress the brainstem to be inoperable. Through the work of such neurosurgical luminaries as Fred Epstein and Gazi Yasargil, some surgeons have attempted to remove tumours of the brainstem. Many brainstem tumours have been removed successfully at the Centre since 1999. The results of these operations have been published in 2 separate peer-reviewed journals….
Teo C, Siu TL. “RADICAL RESECTION OF FOCAL BRAINSTEM GLIOMAS: IS IT WORTH DOING?Childs Nerv Syst Nov;24(11):1307-14, 2008, and
Teo C, Broggi M. “Surgical outcome of patients considered to have “inoperable” tumors by specialized pediatric neuro-oncological multidisciplinary teams” Childs Nerv Syst 26(9): 1219-1225; 2010.
Unfortunately not all patients do well and some of the worst outcomes we have seen have been in these patients. The essence of brainstem tumour surgery can be summarized in a few clear statements.

1. If the tumour is extra-axial, meaning growing from outside the brainstem and “pushing” in, then surgery will more than likely be indicated. Most of these tumours are ependymomas in children and acoustic neuromas or meningiomas in adults.

2. If the tumour is growing from within the brainstem, intra-axial, then they may either be focal or diffuse. Focal tumours may be low grade or high grade. If low grade, then surgery will likely be curative or at least extend survival significantly. If high grade then surgery is unlikely to extend survival but may often improve the quality of life by reducing the need for steroids and improving the response to adjuvant treatment. If diffuse, then surgery is not indicated, even a biopsy is unlikely to offer any useful information. Unfortunately, the diagnosis of diffuse is often made incorrectly as many focal tumours may involve most of the brainstem and appear to be diffuse.

EXAMPLES
Extra-axial ependymoma

Fig 1.      Pre-op MRI that was mistaken as a diffuse brainstem glioma. This patient decided to get a second opinion and agreed to our suggestion of surgery

Fig 2.      Post-op MRI showing a complete resection. The patient has done very well with no recurrence after several years.

Fig 3.      Pre-op MRI of a focal brainstem/low grade glioma. She had several operations at another hospital but the tumour was never removed. She eventually came to the Centre for a second opinion and we suggested attempt at total resection

Fig 4.      Post-op MRI showing complete resection. The patient did very well and is now living a normal life free of tumour 9 years later

Fig 5.      Pre-op MRI showing a focal malignant tumour

Fig 6.      Post-op MRI showing complete removal. The patient was better after surgery but died from tumour recurrence 8 months later

Fig 7.      Pre-op MRI showing the typical appearance of a diffuse pontine glioma. The patient was not offered surgery and died 6 months after this scan

Fig 8.      Pre-op MRI showing a focal brainstem glioma. Despite advise from many other doctors, the parents chose to take the advice given at the Centre to have an attempt at resection

Fig 9       Post-op scan showing an excellent resection but the patient suffered many neurological complications and has never regained independent status