Brain Tumour Embolisation, Endoscopy and Paediatric Surgery

Preoperative brain tumour embolisation blocks the blood vessels feeding a vascular tumour through a catheter, usually one or two days before surgery, so that the operation itself loses less blood. Dr. Rahul Gupta, Senior Director & HOD Neuro and Spine Surgery, Fortis Hospital, Noida, India, uses it for skull-base and vascular tumours, and also uses endoscopic surgery through the nose for pituitary and other skull-base lesions.

Both techniques reflect the same strategy: reach a difficult tumour with as little disruption to the patient as possible. This article covers how Dr. Gupta's team uses the neuro catheterisation laboratory and the endoscope, the special techniques that make large or deep tumours safer to remove, and the paediatric cases he presented. The overall diagnostic framework sits in the complete guide to diagnosis and management of brain tumours.

Brain tumour embolisation before surgery

Some tumours are fed by a rich network of blood vessels. Operating on them directly can mean heavy bleeding, a field obscured by blood and a long operation. Dr. Gupta's department has its own neuro catheterisation laboratory where these tumours are first studied with cerebral angiography and then, where suitable, embolised: a catheter is guided through the arteries to the vessels supplying the tumour, and the vessels are blocked from inside.

When embolisation is used

He uses it for vascular tumours at the skull base or over the convexity of the brain, including:

• Meningiomas, tumours of the membranes covering the brain.
• Haemangiopericytomas, uncommon, highly vascular tumours that also arise from the coverings of the brain.
• Juvenile nasopharyngeal angiofibromas, benign but very vascular tumours at the back of the nose, typically seen in adolescent boys.
• Carotid body tumours, growths at the fork of the carotid artery in the neck.

What it achieves

Embolisation is done in the catheterisation laboratory one or two days before surgery. In Dr. Gupta's account, it reduces intraoperative blood loss, gives the surgeon a clean operative field, shortens the operation, and so improves the patient's outcome.

Case: a meningioma

Dr. Gupta showed a meningioma whose digital subtraction angiogram (DSA, an X-ray of the blood vessels with the background removed) displayed a dense "tumour blush", the stain of contrast that marks a tumour's blood supply. After embolisation the blush had disappeared. At surgery, blood loss was very minimal.

Case: a carotid body tumour

A second patient had a visible swelling in the neck, which MRI confirmed as a carotid body tumour, and the DSA again showed a tumour blush. Because these tumours wrap around the carotid artery, the team first performed a balloon test occlusion: a balloon temporarily blocks the artery while the patient is checked for any neurological deficit. This tells the surgeon in advance whether the vessel could be sacrificed safely if that became necessary. The tumour was then embolised with particles, and the blush faded progressively until hardly any blood flow remained in it. At surgery there was minimal bleeding and the vessels were preserved. Dr. Gupta showed the patient on the second post-operative day.

Endoscopic brain tumour surgery

The second pillar of minimally disruptive surgery is the endoscope: a thin telescope with a camera that brings a high-definition view into narrow spaces. Dr. Gupta highlighted the large, high-definition monitors now available, which give greater clarity and better tissue identification, and recording, which lets the team review its own surgery afterwards.

His team uses the endoscope for:

• Skull-base surgery through the nose, including expanded endonasal approaches that reach beyond the pituitary fossa.
• Intraventricular lesions, tumours inside the brain's fluid-filled cavities.
• Endoscopic third ventriculostomy (ETV), a small opening made in the floor of the third ventricle so that blocked CSF can drain, treating hydrocephalus without a shunt.
• Inspecting the tumour cavity after removal to look for residual tumour.
• Subdural haematomas, in particular acute-on-chronic collections, removed through a mini craniotomy.

Endoscopic third ventriculostomy is examined in more depth, from a separate masterclass, in Dr. Anil Kumar Kansal's article on endoscopic brain surgery.

Endoscopic pituitary surgery

In endoscopic transnasal pituitary surgery, the endoscope is passed through the nose to reach the pituitary fossa and the tumour is removed without any incision on the face or scalp. The pituitary gland sits at the skull base, directly behind the nasal cavity. Dr. Gupta describes endoscopic transnasal surgery as the usual approach for pituitary tumours; only very large tumours extending into the parasellar and suprasellar areas, beside or above the fossa, sometimes require a transcranial approach instead.

His case shows why patients value it. On the first post-operative day the patient was in the intensive care unit; on the second, in the ward, with hardly any sign that surgery had been performed, although the tumour had been removed through the nose.

Special techniques for deep and large tumours

The sitting position for deep tumours

Tumours in the centre of the brain are difficult to localise and reach. Dr. Gupta's team uses special positioning equipment for these cases. He showed a supracerebellar approach performed with the patient sitting up, reaching the posterior fossa from above the cerebellum. In the sitting position, the cerebellum falls away by gravity, opening a natural corridor to deep structures with less need to retract the brain.

Autologous blood transfusion for a large meningioma

A woman in her twenties presented with headache and visual problems, and MRI showed a large anterior skull-base tumour, most probably a meningioma. Before surgery began, the team withdrew about 500 ml of her own blood, a technique called autologous blood transfusion, to be given back during the operation once the bleeding phase was over. Dr. Gupta considers it an effective way to conserve blood, particularly in young patients whose haemoglobin is above 12. The tumour was removed through a craniotomy, and he showed the empty tumour cavity, the patient on the first post-operative day and the patient at follow-up.

Carmustine wafers for recurrent malignant tumours

For malignant tumours, especially recurrent ones, chemotherapy can be delivered directly at surgery. Biodegradable wafers containing carmustine, a chemotherapy drug, are placed in the tumour bed at the end of the operation, where they release the drug locally.

Brain tumour surgery in children

Dr. Gupta noted that brain tumour surgery is sometimes needed in children, and that posterior fossa tumours are very common in this age group. He presented two paediatric cases in detail.

A choroid plexus papilloma with hydrocephalus

A young child presented with a brain tumour and hydrocephalus. The eyes showed the "sunsetting sign", a downward deviation of the eyes that is a feature of raised intracranial pressure, and the fontanelle, the soft spot on an infant's skull, was bulging. The MRI was diagnostic of a choroid plexus papilloma, a usually benign tumour of the tissue that produces CSF, with a frond-like appearance inside the ventricle and associated hydrocephalus. On contrast MRI the lesion enhanced brilliantly. The team removed the bone, removed the tumour, and confirmed the result on a post-operative CT.

A posterior fossa tumour operated on during COVID-19

A child presented with drowsiness, vomiting and headache from a posterior fossa tumour causing hydrocephalus. The team first placed an external ventricular drain (EVD), a temporary tube that drains CSF from the brain to relieve pressure. The child was COVID-19 positive, but because he was unconscious, the team operated immediately, wearing full protective equipment. A near-total excision was achieved, with the ventricular drain visible on the post-operative CT, and Dr. Gupta showed the child at follow-up.

What changes in children

Two practical points from the session apply particularly to children. A stereotactic frame often cannot be fixed to a child's head, which is one reason Dr. Gupta's team prefers frameless navigation-guided biopsy, described in awake craniotomy, neuronavigation and fluorescence-guided surgery. And very large tumours in infants, as at the other extreme of age, may not benefit from surgery, chemotherapy or radiotherapy. For a broader view of brain tumours alongside other childhood cancers, see childhood solid tumours.

Radiotherapy alongside surgery

Not every tumour needs to be removed completely by surgery. For difficult meningiomas encasing major vessels at the skull base, Dr. Gupta's team can perform a subtotal excision and treat the residual tumour with modern radiotherapy such as Gamma Knife or CyberKnife. Gamma Knife radiosurgery is also used for small tumours and metastatic lesions. How surgery and radiosurgery compare as options is explored from a different angle in Dr. Sonal Gupta's article on brain tumour surgery vs radiosurgery.

Indicative costs are on the craniotomy for brain tumour excision cost page, the DSA and embolisation cost page and the cost page for other brain and neurosurgery procedures. The post-operative course is described in recovery and follow-up after brain tumour surgery. Dr. Gupta's practice is summarised on his doctor profile, and his answers to doctors' questions are in the live discussion.