Surgeons say the technique used in the illegal heart operation by an unregistered Brazilian surgeon at Grantham Hospital offers exciting possibilities for treating cardiac disease. The procedure has been pioneered by Dr Randas Batista in more than 500 operations worldwide but is still considered controversial. It involves slicing a chunk of still-beating muscle from the heart's main chamber and sewing the remaining heart together. Dr Batista used the procedure in an emergency operation on a Grantham Hospital patient suffering acute heart failure. His involvement sparked a row because the hospital 'omitted' to apply for his temporary registration, making the operation illegal. Police and the Medical Council will be asked to investigate. The hospital said its main concern was to save the unnamed patient's life. Local surgeons are excited by the technique's possibilities. Prince of Wales Hospital's head of cardiology, Professor John Sanderson, said short-term studies indicated it was very promising. The Batista procedure is used to reduce an enlarged heart to a more normal size. A healthy adult heart is about the size of a closed fist but an enlarged heart can grow as big as a basketball. Doctors describe an enlarged heart as 'very jumpy and floppy', with patients experiencing increasing breathlessness and fatigue. Drug treatment is available but for some patients the only option is a heart transplant - and these are rare. The Grantham patient had been on the transplant waiting list for more than a year. Since his operation, he had been stable, and was recovering, the hospital said. Dr Batista's technique was initially dismissed by the medical community when it was reported in 1995. But it has been adopted as an experimental procedure in dozens of United States medical centres, including the Cleveland Clinic.