AN ASPIRING actress died when her heart was accidentally punctured during cosmetic surgery to correct her protruding chin.

The eight-hour operation to correct the alignment of 20-year-old Alexandra Mills’s upper jaw had been hailed as a success by surgeons. But, unknown to the medical team, a fine tube inserted to monitor her blood pressure had pierced the wall of her heart.

When Ms Mills was given an injection of potassium the next day to aid her recovery the drug leaked through the hole in her heart and triggered a cardiac arrest that led to irreversible brain damage.

An inquest was told that Ms Mills, from Cirencester, Gloucestershire, had been teased at school about her protruding chin. The routine operation, though complex, would have corrected it.

Alan Crickmore, the Gloucestershire Coroner, said that Ms Mills’s death had been a “terrible coincidence”, for which doctors were not to blame. After the hearing her mother, Jane Mills, said: “She’d always wanted to go on the stage. When she was little she was teased at school because of her chin, so she didn’t want to let it stand in the way of her career.

“Everyone who knew Ali loved her and thought she was wonderful. She was full of life and spirit. What happened was just a terrible, freak accident.”

The inquest was told that Ms Mills had a slightly prominent chin and an anterior open-bite, meaning that her upper incisors did not overlap her lower incisors. The operation was part of a long-term surgical plan to correct her jaw line.

In June 2002 she had eight teeth removed, then in February last year she underwent the main procedure to break and reset her jaw line. The operation, known as a bimaxillary osteotomy, was carried out at Cheltenham General Hospital. John Harrison, a consultant surgeon, said that the procedure had been carried out successfully for 25 years.

He added: “The procedure was to separate her upper jaw from the rest of her facial bone so that the teeth met in the correct position. There were no problems during surgery and we were all pleased at that stage with the result.”

However, at some time during surgery or Ms Mills’s recovery, the central venous line that had been inserted into her heart moved and caused a small tear. The next day, while Ms Mills was still heavily sedated, the potassium injected to restore an imbalance in her blood flooded the area around her heart and stopped it.

She suffered massive brain damage and died four days after the operation. A postmortem examination showed the cause of death to be oxygen shortage to the brain due to an arrhythmia in the heart, caused by the potassium.

Recording a verdict of accidental death, Mr Crickmore said that there had been “no human control” over the death. “She must have realised that this was going to be a long and difficult process which would take days, if not weeks, to recover from, but the result would be cosmetically more than worthwhile. She was the unfortunate victim of an unusual event — the terrible coincidence created by the . . . compromised beating of her heart and the potassium itself acting against the best interests of her heart.”