Girl, 15, died during routine surgery at Great Ormond Street Hospital to have four teeth removed

Denisa Alexandra Stefanoaia, known as Alex, died at Great Ormond Street Hospital (GOSH) in London after complications during the operation, which would allow her to have a brace

A 15-year-old girl died while having four teeth removed in a routine dental surgery which was she was told would take no longer than an hour, an inquest today heard.

Denisa Alexandra Stefanoaia, known as Alex, died at Great Ormond Street Hospital (GOSH) in London after complications during the operation, which would allow her to have a brace.

The teenager, from Watford, Hertfordshire, was put under general anaesthetic for the procedure, which lasted 19 minutes and was deemed ‘very straightforward’.

So low was the risk of her dying – experts predicted it to be less than one in 100,000′ – that her family were not warned.

But St Pancras Coroner’s Court heard how Alex, who had mild asthma, sleep apnoea and who was clinically obese, had bitten down on the endotracheal tube during surgery and had stopped breathing.

She was taken to intensive care but was pronounced dead five days later, her brain having been starved of oxygen.

In a statement after the inquest, Alex’s mother said she had lost her ‘best friend’ and that the family had gone through ‘terrible pain’.

Giving evidence remotely at the inquest on Thursday, Dr Atheer Ujam, a senior registrar at GOSH who carried out the surgery, told the coroner that while the patient was a higher risk, he had no qualms about proceeding with the surgery.

He told the inquest: ‘I remember looking at her and her dad (before the operation) and there was a sense that although she was having an operation, it was something that was going to be associated with a good outcome – she was going to have her teeth straight.’

Dr Ujam described the procedure as ‘uncomplicated’, but said he later noticed there was a problem with the patient.

Giving evidence remotely at the inquest on Thursday, Dr Atheer Ujam, a senior registrar at GOSH (pictured) who carried out the surgery, told the coroner that while the patient was a higher risk, he had no qualms about proceeding with the surgery

Giving evidence remotely at the inquest on Thursday, Dr Atheer Ujam, a senior registrar at GOSH (pictured) who carried out the surgery, told the coroner that while the patient was a higher risk, he had no qualms about proceeding with the surgery

He said: ‘I stayed in the theatre to make sure the patient was stable.

‘I finished my notes … I went (back to the operating table) to see what was going on, that’s when I saw Alex – she was blue.’

Dr Ujam said a colleague told him it was a problem with Alex’s lungs, but that a short time later he could see blood coming from her mouth.

He said: ‘I began to feel for a pulse and we couldn’t find one.

‘At that point (a colleague) said we have to start CPR … within 10 or 15 seconds there were many people coming into theatre.’

Dr Ujam said he would not do anything differently were he to be faced with a patient similar to Alex.

Dr Akane Iguchi, consultant anaesthetist at GOSH, was also in the operating theatre at the time and said she began to become concerned when she was unable to ventilate Alex’s lungs after the procedure.

She said: ‘We were trying to improve her lung capacity.

‘I looked over at Alex’s face and she was biting the ET (endotracheal) tube and she was becoming blue.’

Dr Iguchi told the coroner that Alex’s obesity meant she may have been deprived of oxygen for only ‘a matter of seconds’ before turning blue.

She said: ‘Less than one minute – much, much less than healthy children. In her case, because of her severe obesity, her oxygen consumption is very high.

‘All the factors combined make her very risky.’

In a statement, Alex's mother Angelica Stefanoaia described how the death of her daughter - her 'best friend' - had an impact on her life

In a statement, Alex’s mother Angelica Stefanoaia described how the death of her daughter – her ‘best friend’ – had an impact on her life

In a statement, Alex’s mother Angelica Stefanoaia described how the death of her daughter – her ‘best friend’ – had an impact on her life.

‘I have cried every day since she died, desperate to bring her back,’ she said.

‘I begged them on my knees to do everything they could for her and save her and they simply said she wouldn’t wake up.

‘When they told me she was poorly after the surgery, I never for one moment thought she would die.

‘Please, no other family should have to go through this terrible pain.’

Mark Bowman, a partner at Fieldfisher which is supporting the family at inquest, said: ‘Going through an inquest investigating the death of your daughter is a horrific experience.

‘The hope is that the family will receive some answers which will allow them to properly grieve for Alex.’

The inquest continues.