Great Ormond Street: What’s it like to perform an operation only one child in three survives unscathed?

Meet Dr Adam Rennie, the neuroradiologist battling the odds every time he picks up his scalpel

Dr Adam Rennie admits that when he has finished his work in the operating theatre he’s often “drenched” with sweat, such is the concentration required. But it’s little wonder, given the sort of procedures the 41-year- old performs day in, day out.


A neuroradiologist, Dr Rennie’s specialism is vascular malformations in the brain. These are repaired through the use of tiny catheters, barely thicker than a human hair, that are inserted through the patient’s groin and meticulously navigated upwards through the body. It demands mind-boggling technical skill, particularly when operating on children, as Dr Rennie does up to two days a week at Great Ormond Street Hospital in London.

One of the procedures is so rare that he is one of only three doctors in the UK able to treat the estimated 15 or so cases that occur each year. Known as a vein of Galen malformation, it’s being shown on television for the first time, in the latest in a fascinating documentary series that takes the cameras into the heart of the hospital, capturing the ethical and human dramas that unfold there each day.

It’s safe to say that viewers will never have seen anything quite like it: vein of Galen malformations require the injection of glue or tiny metal coils into the brain’s arteries – expertly introduced by those tiny but lengthy catheters – to block abnormal connections and correct blood flow. “When we’re mixing the glue, which we use to block the abnormal vessels in the brain, the smell of it… In fact, just talking about it now and my heart is starting to race,” says Dr Rennie, with a nervous laugh. 

Dr Adam Rennie

The procedure carries grave risks – one small mistake could tear the vessels – particularly as it’s almost always carried out on terrifyingly fragile newborn babies and toddlers. Dr Rennie admits the age of his patients is something he tries not to think too much about once surgery is taking place. “Once I’m in the theatre, everything else is shut out from my mind and I’m entirely focused on the vessels enlarged on the screen in front of me, rather than thinking about what’s under my hands. Otherwise, I would be almost paralysed with fear. But, of course, you think, ‘This could be one of mine,’ and that isn’t easy.” He is the father of two girls, aged six and eight, and a two-year-old boy.

Quietly spoken and humble, Dr Rennie combines surgical expertise with a great capacity for empathy. He is painfully aware of the difficulties of presenting complicated medical data to parents, which they must juggle along- side the anxiety of caring for a sick child. 

Building trust takes time, he acknowledges, particularly when it comes to gaining consent for procedures that are in themselves dangerous, but may save a child’s life. “First of all, I try to draw a picture of the brain vessels, which helps a little bit with understanding, and I try not to get parents’ consent on that first occasion – they need time to formulate the questions in their own minds and you need time for a relationship to form,” he says.

The hardest part for parents to absorb, of course, are the statistics that dictate the likelihood of a reasonable outcome. In the case of vein of Galen malformations, they are a tough sell – only one in three of those operated on will emerge alive and free of any impairment – although balanced against that is the likelihood that any child with the condition will face severe developmental problems or death without treatment.


“With vein of Galen, we deal in thirds – a third are likely to have a good outcome, a third are likely to have some impairment to a greater or lesser extent, a third will die. I find that most parents can grasp those figures,” Dr Rennie says. “It’s when you start breaking those percentages into smaller groups that it’s hard to work out what that means for your child.”