Original title: Brain Surgery When He is Awake

He lies in the operating theatre, still and seemingly asleep.

Part of his head is behind a transparent curtain. From behind, his skull has been sawn open and neurosurgeon Ng Wai Hoe begins the delicate process of removing a walnutsize tumour from the deep recesses of his brain.

Photojournalist Wang Hui Fen, who is documenting the operation, zooms in for a close-up. The patient opens his eyes a fraction, looks straight at the camera, raises his right arm and gives that universal sign of approval, a thumbs up.

Meet KPMG auditor Oh Zhi Long, the world’s most upbeat brain surgery patient.

He is awake, so Associate Professor Ng and anaesthetist See Jee Jian can talk to him to assess the effects of the surgery.

The job is a delicate balancing act: Remove too little tissue and the tumour will most certainly come back. Take out too much, from the wrong spot, and Mr Oh could be rendered unable to speak, or paralysed for the rest of his life.

Earlier that day – on the morning of March 28 – the atmosphere is relaxed as the operation is set to begin.

Multiple checks are done before the procedure, including marking the site of the growth and confirming for the umpteenth time that the tumour lies within the left frontal lobe – the seat of language for righthanded folk, and an important movement control centre as well.

“Finally,” says Mr Oh with a smile as he is wheeled into an operating theatre at Tan Tock Seng Hospital about an hour later.

Prof Ng, medical director of the National Neuroscience Institute (NNI), is a veteran of such operations, having done them since the early 2000s, performing up to 15 a year and more than 200 in total.

He removes Mr Oh’s glasses and, pointing to his hair, asks him how close a shave he wants. “I’m a jack of all trades,” he quips, as he whips out his clippers. “Take it all off, it’s only hair, it will grow back,” Mr Oh replies. “I have no regrets.”

Awake brain surgery is done in less than 10 per cent of brain tumour cases at the institute, when surgeons need to operate on an area of the brain that involves or is close to regions that control critical body functions, or sensory and language capabilities. In such cases, it is critical for the patient to be conscious so the surgeon can monitor vital functions during the procedure.

Senior manager of operating theatre service Lee Sow Fong, who oversees the procedure, is a model of efficiency. She reminds The Straits Times team – the first to document this operation here – not to disrupt the work of the medical professionals.

“Do not get in their way,” she warns us sternly.

Mr Oh is sedated, but only mildly. Associate Professor See explains: “During certain periods, he needs deeper sedation, but sometimes we need his cooperation and we use different drugs to achieve that.

“Every patient is slightly different, so we have to find the level that is appropriate for him.”

Throughout the procedure, he carefully monitors Mr Oh’s vital signs including his heart rate, breathing and blood pressure, and talks to him to keep him calm.

Prof Ng and NNI’s director of neurosurgery research Nicolas Kon begin by cutting through the skin on the head, before drilling through the skull.

“You will hear a drilling sound, just relax,” Prof Ng tells Mr Oh, as the sound of metal crunching through bone fills the quiet of the operating theatre.

Once the piece of skull is lifted, he slices through the dura – the tough membrane which protects the brain – pulling it back and attaching it to the skull with neat surgeon’s stitches to make sure it “remains tight” to minimise bleeding.

Then he cuts through the arachnoid or spider membrane, which cushions the central nervous system, and finally the delicate pia membrane on the brain’s surface.

Pink, glistening and delicate, the body’s most important organ is now exposed.

The brain, home to 80 to 100 billion neurons, does not have any pain receptors and cannot feel anything – luckily for Mr Oh. So it is the only major organ which can be operated on while the patient is awake.

Every effort is made to ensure he is comfortable. In fact, the transparent drape separating the part of his head being operated on from the rest of him is Dr Kon’s innovation.

Previously, surgeons took the lead from their overseas counterparts, using the classic green opaque hospital drapes to do the job. But this could make a patient feel claustrophobic.

It was also difficult for the surgeon, from his position behind the drape, to monitor the patient’s responses, explained Prof Ng.

So they rigged up the transparent sheet on a metal stand, much like a shower curtain.

Mr Oh’s head is also not clamped – another NNI first.

Instead, it rests on a horseshoe cushion, making him much more comfortable.

With neuro-navigation technology, a tracker is stuck to Mr Oh’s forehead, so that the MRI scanner can accurately track where the tumour is in real time, even with slight movements.

NNI doctors and scientists are currently studying the use of a fluorescent dye which lights the brain tumour up, while healthy tissue is unaffected. If successful, this will be a cheap and effective way of singling out the tumour so that it can be removed.

Once the brain is exposed, a little cerebrospinal fluid – the colourless liquid which surrounds the brain – is collected for research.

The tumour will also be deposited in the NNI’s brain tumour bank, which has amassed over 130 samples in the last decade.

The idea is to study the genetic make-up of the tumour, so that doctors will one day be able to tailor specific treatments for different patients, based on the tumour’s genetic signature.

“Zhi Long, are you awake now?” asks Prof See, head of anaesthesiology, intensive care and pain medicine at Tan Tock Seng Hospital. “We’re going to start very soon, are you comfortable?” The patient nods slightly. Another hour has gone by.

As Prof Ng delves into the tumourous tissue, which is an unhealthy yellowish white compared with white healthy tissue, Prof See asks him to make a fist, and moves forward with an iPad.

“Can you see without your glasses?” asks Prof See. “I’ll try,” Mr Oh replies drowsily.

He is asked to name common images on the iPad, ranging from a car to a dolphin to roti prata.

“Can I see what’s in my head also?” Mr Oh asks, to which Prof Ng responds: “Later we’ll show you.” Mr Oh has a few more questions – “Somehow my legs feel numb now, is it due to the brain?” (“No, it’s probably just the local pressure.”); “Is the tumour cutting into my vocal area?” (“No, the vocal area is behind it, so we’ll have to ask you some more questions later.”) “Okay, just cut more lah,” Mr Oh responds.

The naming test goes on as Prof Ng delves deeper into the brain to excise the tumour, and about four hours after Mr Oh is first wheeled into the operating theatre, the growth is removed.

Then comes the process of sewing back the dura and screwing the skull shut with titanium plates, and finally stitching up the scalp which had earlier been peeled back like the skin of a fruit.

Prof Ng tells him: “You did very well,” and his patient squeezes his hand one more time. Mr Oh is even able to move himself onto the hospital bed that will be wheeled into the recovery ward.

When he wakes up, he may remember very little of the entire procedure.

But he tells ST later: “I was joking but I felt a bit terrified. For my first surgery, it was quite a major one.” Primary brain cancers are rare, afflicting about 25 to 30 in every 100,000 people, said Prof Ng.

But if not treated, they can be extremely disabling and life-threatening because they grow rapidly and invade surrounding brain tissue.

In Mr Oh’s case, it was in the left frontal lobe, the part of the brain which has a lot of “reserves”, and is able to cope with significant damage with minimal or no deficit.

To make sure the cancer was eradicated, he also had to go through 30 sessions of radiotherapy, as well as eight months of chemotherapy.

After all that, his prognosis is good. Said Prof Ng: “As the tumour is largely benign, we hope that the aggressive treatment will lead to a cure.”

Mr Oh, who stayed active even when undergoing treatment, went back to work in July with a new zest for life. He exercises regularly and is determined to keep himself even fitter than he was before the operation.

He also plays basketball and tries to eat healthily. “I’m lucky that everything came together,” he said.