THE complexities of brain surgery will be laid bare as the BBC documentary series Scotland's Superhospital continues on Monday.

Viewers will see consultant neurosurgeon Roddy O'Kane perform an awake craniotomy procedure to remove a cancerous tumour from the brain of his patient Peter Furey at the Queen Elizabeth University Hospital in Glasgow.

Mr Furey, 52, from Irvine was diagnosed in 2013. As the tumour grew in size, the former security guard began to suffer increasingly frequent and debilitating epileptic seizures.

He faced the crossroads of an unenviable dilemma: left untreated his condition would continue to deteriorate, while any surgery to remove all or part of the tumour carried huge risks including brain damage and permanent paralysis on his left side.

The 6cm (2.5in) tumour was situated on what is known as the primary motor strip and as Mr O'Kane states: "if I chop that out from anyone, I paralyse them".

Due to the risks involved, not all surgeons would have chosen to operate. "I do take a more aggressive stance than some other people do in neurosurgery," Mr O'Kane admits. "That doesn't make me better. That is just my stance.

"It is high stakes. This is not a simple thing like when you meet someone to do an appendectomy. There is a relationship of trust that has been established over multiple clinic visits.

"When you meet me for the first time and I say: 'I'm going to open up your head, then wake you up, chop a bit of your brain out and probably paralyse you', I think you would need to see a psychiatrist if you said yes to that straight away as a far as I'm concerned."

Ultimately, the final call on whether to proceed came down to Mr Furey who says he took two months to consider the decision. The programme charts his journey as he prepares for the six-hour, potentially life-changing operation.

The bond forged between patient and doctor is evident in their easy rapport and good natured banter as Mr Furey bravely declares: "In Rod I trust."

"When you meet consultants and surgeons they are usually stuffy, but with Roddy I could relax," he says. "He tells you it straight and doesn't camouflage anything. I knew exactly what I was letting myself in for."

Mr Furey nicknamed the team of neurophysiologists monitoring his condition the "satnav guys" because they used electrodes to map the brain and help guide Mr O'Kane as he operated.

An awake craniotomy is a procedure carried out just 10 times a year by the surgical team at the hospital and not one undertaken lightly.

Mr O'Kane is the antithesis to the "God complex" criticism often levelled at doctors as he reveals the human side beneath his professional bedside manner.

"I'd like to pretend I'm calm and collected – I'm not," he says. "There used to be a joke about why surgeons wear theatre masks and that's because we're screaming underneath it."

He touches upon the constant internal struggle that many surgeons face in striving to do their best.

"There is a fight in your own ego," says Mr O'Kane. "You can't help but want to do more, but you have got to do that sensibly. What you gain with experience is knowing when to stop.

"Performing surgery like this is kind of strange. When I see a patient moving a lot afterwards I always have that negative thought of: 'I haven't taken enough.' Alternatively when I see patients and they're very weak, I think: 'I've taken too much.'"

Mr O'Kane admits it drives his family "crazy" as he painstakingly dissects his own surgical performance in the days and weeks afterwards. "I'm permanently questioning: 'Were you good enough?' 'Did you harm them?' There is that balance," he says.

Although the 40-year-old from Derry-Londonderry in Northern Ireland draws solace from the staunch belief that every operation completed makes him a better surgeon going into the next one.

"People have an idea that a consultant is qualified and that's it, they are perfect, but are we hell," he continues. "You learn by every single case. When I stop learning is the day I retire."

Scotland's Superhospital is on BBC One, Monday, 9pm