When Pippa Plaisted was told that she would need a fourth breast cancer operation, it was not the surgery that worried her most. Like many people, the idea of an operation did terrify Pippa, a 46-year-old personal trainer, but this procedure — to reposition an artificial valve attached to her breast implant, which had been inserted after a mastectomy — promised to be a straightforward 45-minute job. What Pippa was more worried about was the fact that the operation would require a general anaesthetic.

After each previous operation, Pippa, a mother of two, had reacted badly to the anaesthetic: “I’d be feeling dizzy and falling over for months afterwards. It would take me so long to feel well again, and it was getting worse each time.”

With the operation only a few weeks away, she sought help from her hypnotherapist, Charles Montagu, a practitioner based in South Kensington, West London, to overcome her fear of the surgery. When Montagu heard about Pippa’s difficulties with general anaesthetic, he suggested that hypnosis could be used to neutralise the pain of surgery, a technique known as hypno-anaesthesia, which, he believes, can be applied to most types of operations except those requiring deep invasive surgery, such as a heart operation. He believed that by entering a deep state of relaxation, known as deep trance, Pippa would be able to undergo the surgery without needing drugs at all.

The mechanism by which hypno-anaesthesia relieves pain is not yet precisely understood. One way is thought to be by the focusing of attention away from the source of pain. “All of our senses are selective,” says Montagu. “If you are sitting down right now, you might not be aware of the chair that you are sitting on. But if you are in a boring lecture, you become very aware of the chair.” During surgery, hypnosis can be used to divert attention away from the area being operated on and focus it elsewhere, he says.

Another way that it might work is by a reinterpretation of pain signals, according to the hypnotherapist Dr John Butler, who holds a PhD in medical science and lectures at the GKT School of Medicine in southeast London. “By instructing the brain to relax and to be unconcerned about pain, the pain signal can be reinterpreted as a non-distressing sensation,” he says. “The pain signal is definitely received at the pain receptor; it travels up the spinal cord and into the brain. And that’s all quite normal so far. But then, at a crucial point, it seems that the hypnotic activation in the brain re-routes the signal so that it gets understood as a harmless sensation.”

The idea that hypnosis alone can be powerful enough to block out the pain of surgery may seem far-fetched. But research has provided clear indications that hypnosis can alter the brain’s perception of pain. After deciding that she wanted to try hypno-anaesthesia, Pippa phoned her surgeon, Adam Searle, to ask if he would be willing to perform surgery under these conditions. To her relief, Searle thought it was worth a try. To act as a safeguard, and also for Pippa’s reassurance, he arranged for an anaesthetist to be present in the operating theatre. Searle says: “My fear was that halfway through the procedure the hypnotherapy might not be as effective as hoped and we would have to call upon more conventional anaesthetics.”

For hypno-anaesthesia to work, the patient needs to access a deeper state of trance than in an ordinary hypnotherapy session. To be sure of being able to reach the required state of trance on the day, Pippa had three hour-long practice sessions. Montagu would instruct her to focus her attention on her breathing, and then gradually count her down into a deeper and deeper trance.

To demonstrate how effectively pain could be blocked, Montagu — with Pippa’s permission — pinched the sensitive skin on the inside of her arm hard. Pippa was amazed. Even though her arm was bruised, she had felt no pain.

On the day of the operation, Montagu took Pippa through some of the relaxation techniques that they had practised. By the time the theatre was ready for her, Pippa was feeling confident: “I walked — or rather floated — down to the theatre, completely calm and in control.”

In the theatre, Montagu stood at the head of the operating table, his thumb resting gently on Pippa’s forehead. Within about ten minutes he had talked her into the required state of deep trance. The staff in the operating theatre couldn’t help wondering what reaction Pippa would have to the first incision.

“There was a moment of anticipation that, when I put the knife in, this poor girl would sit up and run out of the room,” Searle says. But, in fact, throughout the operation Pippa, despite being conscious and aware of her surroundings, felt no discomfort whatsoever. “The surgeon was cutting and sewing inside me, but I could not feel anything,” she says. At each stage of the operation, Searle would gently reassure her that everything was going well, and tell her what was going to happen next.

To Searle’s surprise, the hypno-anaesthesia had a remarkable physical effect. Pippa bled far less than would normally be the case in such an operation. He later learnt from a colleague, who is an anaesthetist, that reduced bleeding is a common characteristic of operations performed under hypno-anaesthesia.

Marie-Elisabeth Faymonville, an anaesthesiologist at Liège Hospital in Belgium, claims that anaesthetic drugs inhibit the natural tendency of blood vessels to constrict in response to an incision; secondly, patients knocked unconscious by anaesthetics have to breathe with the help of an artificial respirator. This puts pressure on the chest and, in turn, increases bleeding. In contrast, hypno-anaesthetised patients are conscious and breathe normally, and bleed less as a result. According to Searle, this made Pippa’s surgery less tricky to perform: “The various layers of tissue are much more clearly visible if they are not bloody. It is easier to be accurate.”