(Nov 5) WITH eyes wide open, he could hear the surgeons cutting into his skull to remove a tumour.

Mr N Singa, 45, said: 'I was trying to guess what they were doing from the sounds.'

He was undergoing awake-brain surgery.

This form of surgery has been around for 10 years, while the virtual reality version pioneered by Singapore surgeons has been in practice for about seven years.

For Mr Singa, surgeons had to remove a 3cm-diameter piece of his skull bone on the top right side of his head.

Then they operated on his brain, trying to remove as much of a 6cm-diameter cancerous tumour as they could.

The more tumour they removed, the better his chances of a longer survival.

All Mr Singa could do was to tell himself to relax during the three-hour surgery in January.

Practitioners such as Dr Yeo Tseng Tsai, a senior consultant neurosurgeon at National University Hospital (NUH) who operated on Mr Singa, have been constantly improving brain surgery techniques to reduce the chance of neurological deficits occurring after such surgery.

MORBIDITY RATE

Mr Yeo said he has been doing an average of about four to five awake-brain operations a year. The morbidity rate - which includes death and post-operative complications - is 5 per cent.

He said: 'Whether the surgery needs to be done awake or not depends on the tumour and its location.

'It is usually done only when the tumour is located in a particularly sensitive part of the brain such as the language area or the motor (movement) area.'

While Mr Singa's surgery took three hours, the duration could vary depending on the complexity of the operation, and the rate of recovery also depends on the patient's condition.

Awake-brain surgery is becoming more common worldwide as neurosurgeons and anaesthesiologists gain more confidence in the technique, Dr Yeo said.

As surgeons are now better able to identify pathways which affect the patients' speech and motor abilities, the challenge is to remove as much of the tumour as possible without damaging the patient.

As Mr Singa was left-handed and the large recurrent malignant brain tumour is sitting on the right side of the brain - where important speech areas and motor pathways of the brain are - Dr Yeo decided on awake-brain surgery.

Most people are right-handed and their language-dominant hemisphere is located in the left side of their brain.

During surgery, the advantage is that Dr Yeo could map out exactly where Mr Singa's speech and motor areas are in his brain.

'If I stimulate a certain part of the brain and he suddenly stops talking during a naming task, then we know that this is a sensitive area for language and we must not damage that area,' he said.

By keeping Mr Singa awake during surgery, Dr Yeo could also monitor the patient's motor pathways, which would impact on his ability to move his limbs.

MOVE LIMBS

Dr Yeo said: 'I would ask him to move his fingers, arms, legs during the surgery. This tells me how far I can go surgically without damaging him.'

The end result: more than 90 per cent of Mr Singa' tumour was removed without him suffering any speech impairment or paralysis.

This was a far cry from that day in October last year when Mr Singa first had any inkling that something was wrong.

A sudden dizziness hit him while he was driving a 10-tonne lorry along the Pan-Island Expressway.

He said he suddenly saw a dizzying swirl in his right eye.

He managed to pull his huge vehicle to the side of the road, stop it and call his company.

Then he blacked out.

When he woke up, he was in NUH and throwing fits.

Doctors had diagnosed a 3cm-wide malignant brain tumour.

He needed surgery urgently.

After his first brain surgery and radiation treatment, he thought his ordeal was over, but his tumour returned with a vengeance in January.

This time, his surgeon, Dr Yeo, felt that he could not risk operating on Mr Singa's brain under general anaesthesia.

'The tumour was located on the right side of his brain and it was twice as big as the first tumour,' Dr Yeo said.

GOOD PROGRESS

After his successful awake-brain surgery, Mr Singa is now on chemotherapy and his last brain scan done a week ago showed that the disease had not progressed.

His wife Madam A Meena, 41, a nurse, said: 'It is fantastic what the surgeons have done for him. We now take it a day at a time and hope that the tumour does not return.'

The couple said they have not calculated the medical cost so far. It is partly paid by Medisave savings.

Mr Singa has stopped working as a driver and is concentrating on getting well.

'It is an amazing feeling to be awake while doctors are working on your brain,' he said. 'I didn't feel any pain at all during the surgery.'