The surgeon, who represented himself, told the Manchester hearing, said he had been suffering from "poor vision" at the time and claimed it would be 'harsh' to strike him off.

He added: "I want to apologise to all the patients. I didn't experience operative difficulties, in removing whatever I removed. Everything had gone along fine and it was not difficult to remove.

"It was only later I realised it was not the appropriate part. The operation itself, the technicality, was fine but the wrong specimen was removed.

"I have performed hundreds of appendectomies. this was due to lapse of judgement."

But expert witness, Dr Michael Zeigerman, said: "If you feel you are not capable for any reason then you should not perform the procedure. If you are over tired or feel you are impaired in any way your duty is to the patient. You must say I can't do this I must ask for help, there's always someone at the end of the phone.

"If your vision is impaired and you are tired you need to ask for help to lower the risk of 'never events'.

"Your responsibility is to your patient and if you feel impaired you should seek help. If you are visually not good you shouldn't be operating. If your ability is impaired you shouldn't start an operation or if you become unwell then you should ask for help. Sometimes your visibility does start to get a bit blurred and you stop and go for a cup of tea but you don't just carry on.