Complex Skull Base Tumours

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Complex Skull Base Tumours

WHAT MAKE SOME BRAIN TUMOUR COMPLEX?

Brain is the most complex organ of our body. Most types of brain surgery are critical and complicated processes that require expert surgical care. Each surgery is treated on a case-by-case basis because the outcome may vary in each case. Although surgeons are extremely careful and thorough while operating, brain surgery is associated with several risks. It can also take time to recover after brain surgery, especially if open surgery is being performed. Brain surgery is not always dangerous. All surgical procedures carry some amount of risk, whereas brain surgery carries a higher risk because it is a major medical event.

Risks of brain surgery

Risk may vary with the type of brain surgery and the problem being treated. Possible risks associated with brain surgery include

Bleeding inside the brain
Infection in the brain
Blood clots
Inflammation and swelling of the brain
Impaired or complete loss of speech, vision, coordination, or balance
Memory problems or loss of memory
Stroke
Seizures
Coma
Reaction to anesthesia

Vestibular Nerve Schwanoma (acoustic neuromas)

Vestibular schwannomas or acoustic neuromas are the most common and typically cause hearing loss and ringing in the ears (tinnitus); as they enlarge they may also cause imbalance and incoordination as well as facial weakness. Large tumours need surgery to release the pressure on the brainstem, whilst smaller tumours could be treated with radiosurgery.

MRI

Micro Cranitomy

Tumour Removal

Trigeminal Schwanoma

Trigeminal Schwannoma is a benign tumor of the nerve sheath arising from the perineural schwann cells of the trigeminal nerve (5^th cranial nerve). Trigeminal schwannomas are rare accounting for 0.07–0.3% of all intracranial tumors and 0.8%–5% of intracranial schwannomas. they usually present with facial pain, numbness and paresthesia in the distribution of one or all the divisions of the trigeminal nerve depending on the location of the tumor. MRI is the gold standard for evaluation of trigeminal schwannomas because of its multiplanar capabilities and better soft tissue contrast. It helps in diagnosis and in planning the surgical approach. Surgery is usually performed to remove schwannomas, although radiosurgery is commonly used for schwannomas, particularly if they are small.

Postoperative MRI

Residual tumour, which was then treated with Radiosurgery

9th Nerve Schwanoma

This 50 year old lady had severe headaches, imbalance while walking, difficulty in swallowing and speaking.

The MRI brain showed a large tumour in front of the brainstem causing severe compression and dysfunction of the nerves involved in swallowing.

CT SCAN after surgery

The patient did very well after surgery

Meningioma

A meningioma is a tumor that forms on membranes that cover the brain and spinal cord just inside the skull. Specifically, the tumor forms on the three layers of membranes that are called meninges. These tumors are often slow-growing. As many as 90% are benign (not cancerous).

It isn’t clear what causes a meningioma. Radiation therapy, female hormones and genetics may play a role. In most cases, the condition is non-cancerous.

Symptoms depend on the size of the tumour, changes in vision, headaches, hearing loss and seizures.

A small, slow-growing meningioma that isn’t causing signs or symptoms may not require treatment. When required, treatment might involve surgery or radiation.

Surgery to treat a meningioma is a complex procedure that is not without certain risks and complications. These are very vascular tumours, there can be considerable blood loss during surgery. They can invade important structures, making them difficult to excise completely. It is then wiser to leave some tumour behind and follow their growth by MRI.

Large Falcine Meningioma - MRI Massive Blood Loss

Meningiomas are highly vascular brain neoplasms that are often associated with substantial blood loss during surgical resection. Sometimes. Blocking off the blood supply ( Embolization) to the tumors can be a preoperative adjuvant therapy that has proved to be particularly effective in mitigating blood loss during surgical resection. These are called angiomatous meningiomas. Angiomatous meningioma is a rare and distinct variant of meningioma and accounts for 2.1% of meningiomas. Gross total resection is the treatment of choice for angiomatous meningioma. Postoperative radiotherapy may help patients with residual tumors. Angiomatous meningiomas belong to WHO grade I and have a favorable prognosis, The completeness of surgical resection is the single most important factor in deciding prognosis.

Giant, highly vascular meningioma

Total tumour excision

Patient After Surgery

LARGE MENINGIOMA INFILTRATING IN SSS-MRI VENOGRAM

Dural venous sinuses are a group of sinuses or blood channels that drains venous blood circulating from the cranial cavity. The dural venous sinuses lie between the periosteal and meningeal layers of the dura mater. They are best thought of as collecting pools of blood, which drain the central nervous system, the face, and the scalp. All the dural venous sinuses ultimately drain into the internal jugular vein and then to the heart.

Since meningiomas arise from the dura mater, sometimes the tumour can invade these dural sinuses making total tumour excision difficult.

Surgical treatment of meningiomas next to venous sinuses is difficult because of their irregular growth patterns and infiltration into the venous sinuses, making gross total resection impossible in some patients. Radical resection of meningiomas invading the major dural sinuses remains controversial.

If the sinus is incompletely occluded or adjacent drainage vein could not be dissected from tumor, subtotal resection of the tumor followed by SRS may be a good alternative treatment option.

Giant meningioma in the midline

This tumour infiltrated the major dural venous sinus

Small tumour was left behind, which was treated with Radiosurgery

MRI Venogram After Surgery/Residual tumour

Anterior Clinoid Meningioma

Visual loss is the very common presenting symptom in these tumours^,since they are situated just above the optic nerve. The characteristic onset usually occurs with unilateral failure of vision loss associated with primary optic atrophy^.In some patients, loss of vision may extend to the opposite eye^.Visual field defects in the form of concentric narrowing of the visual field, central scotoma, and temporal hemianopsia can be seen in patients; however, the extent depends on the degree of the involvement of the chiasm and the optic nerves^.Headache is another most common symptom in these tumors, generally over the orbital or retroorbital field.

Clinoidal meningiomas remain a challenging pathology because of their intimate relationship to vital neurovascular structures, like optic nerves, internal carotid artery, to name a few.

MRI AFTER SURGERY

PATIENT AFTER SURGERY

With permission

Pertoclinoid Meningioma

Petroclival meningioma is a benign and slow-growing tumor that occurs deep within the center of the skull base, which is a very difficult location to reach surgically. Patients may experience headaches, double vision, hearing loss, dizziness, facial pain or numbness, facial weakness, and loss of coordination.

Petroclival meningiomas are regarded as probably the most difficult tumour to be treated by microsurgery. Frequent tight brain stem adherence as well as encasement of the basilar artery, its perforators and cranial nerves adds to the sometimes extreme difficulties of surgical tumor removal.

The treatment modalities considered in such tumors are microsurgery alone, microsurgery, and adjuvant radiosurgery, though microsurgery is the primary treatment.

Large petroclival meningioma

CT Scan After Surgery

Partial Tumour Removal During Surgery