Surgeons perform first brain tumour removal through eye socket in Singapore

SINGAPORE – A team of surgeons from the National Neuroscience Institute (NNI) and Tan Tock Seng Hospital (TTSH) has removed a 2.5cm brain tumour through a patient’s eye socket.

The eight-hour surgery, which harnessed a technique used for the first time here to remove a tumour, was carried out in November, and the patient, 38-year-old Teong Wen Han, was able to leave the hospital after only three days.

Mr Teong, a learning and development manager, suffered a seizure on Oct 9 before crashing his car on the CTE, damaging four vehicles and destroying a lamp post near the Bishan exit.

“The last thing I remembered was passing some fruits to my parents before starting my journey. I regained consciousness at the hospital with my neck in a brace, and I was lying on a spinal board,” he said.

Mr Teong said that according to a paramedic, the witness who called the Singapore Civil Defence Force had told them he was “unconscious and twitching”.

“So, at the emergency department, I went through several tests, including a CT (computed tomography) scan, to ascertain why I crashed,” he told The Straits Times.

From the scan, doctors found a 2.5cm brain tumour behind his right eye.

Mr Teong said the closest thing to a symptom that he experienced was a headache every morning, “but that was solved after my morning coffee”.

“I always thought it was because of the lack of caffeine,” he said.

The tumour was growing from the protective layer covering his brain. Its location made it hard to reach if surgeons adopted the traditional open approach, where a section of the skull is removed to create wide access to the brain.

It was also in a high-risk area. “Due to its location, it was more difficult to reach – because it is at the base of the skull and the brain is on top of it,” NNI neurosurgeon Jensen Ang explained.

“It was also quite close to the optic nerve as well as some of the blood vessels and the cranial nerve that controls eyeball movement.”

The surgical team, comprising two neurosurgeons – Dr Ang and Associate Professor Ang Beng Ti – an ophthalmologist, and an ear, nose and throat (ENT) specialist, opted for a minimally invasive surgical technique through the eye socket, called transorbital neuroendoscopic surgery (TONES).

“Surgery is all about developing the safest corridor of approach to something so that we do not disrupt critical structures along the way,” said Prof Ang, a senior neurosurgeon.

Since Mr Teong’s tumour was right behind the eye socket, “rather than going in from the top, we can go in from the front”, he added.

Traditionally, surgeons would have opened the skull near the back of the eye socket and removed small sections of bone at the skull base to create a clearer, more direct path to the tumour, to minimise disruption to delicate brain tissue.

“The covering of the brain or the meninges needs to be cut. That is the layer from which the tumour arises. When we see the tumour, we remove it by peeling it away from the surrounding brain structures,” Prof Ang explained.

He further noted that traditional open skull surgery can leave visible long-term effects, including facial asymmetry due to muscle wasting around the surgical site.

Removing the growth through the eye socket

Indeed, Mr Teong picked TONES “because of vanity”.

With the TONES technique, the surgeons access the brain through tiny incisions in the eye socket.

Prof Ang said it was “critical that the specialists on the team worked together to really pull off this landmark case”.

Eye specialist David Law from TTSH said his role was to ensure the neuro- and ENT surgeons had unobstructed access through the eye socket to reach and remove the tumour.

“I made a skin incision about 2cm in length within the upper eyelid crease so that when it heals, it becomes less obvious. After which... I removed the lateral part of the bone of the socket, allowing access of the instruments through the orbit, to the base of the skull.”

He also made sure that the optic nerve was not damaged during the surgery by constantly checking Mr Teong’s pupils.

ENT surgeon Tan Jian Li’s role was to enable the surgeons to see inside the “very deep and narrow hidden corridor” via an endoscope – a tube with a tiny camera and light at its tip.

“The endoscope controls what we see, keeping our target in sight, as well as critical structures like the nerve that supplies the eye, and the vision within the view of the whole surgical field,” he said.

Dr Tan, who is from TTSH, said that essentially, there were four instruments inside the eye socket during the surgery.

“In my one hand, I had the scope, and my other hand served as a retractor, or a third hand to the primary surgeon. The neurosurgeons were controlling two other instruments,” he added.

Like any well-choreographed dance, rehearsals were necessary – and that was what the team did, using a 3D-printed model taken from the scans of the patient.

“(The model) allowed the different specialities and the disciplines to discuss how we were going to approach the operation, which was the angle to adopt, and what were the critical things that we needed to take note of,” Dr Tan said.

It was only about a month later, on Nov 11, that the surgery was successfully carried out.

Mr Teong was discharged without any neurological or eye complications.

The biggest life adjustment for him is not being able to drive for a year, and having to learn to depend on public transport.

He has been weaned off his anti-seizure medications and, once given the all-clear, will be able to get back behind the wheel again.