Heart surgeons in Bristol did not perform the recommended number of operations each year to maintain their skills, a public inquiry has heard.

The evidence was presented after the BBC revealed they may have continued using an old procedure because they doubted their competence at a modern technique.

The old method - senning - corrects heart defects but leads to an early death.

The newer method - known as an arterial switch - has no such effect.

Procedure was ditched

Mr James Wisheart - one of the two shamed Bristol surgeons - continued to use the senning method even after heart units around the UK had stopped routinely using the procedure.

Mr James Wisheart was struck off by the General Medical Council

And last week the Bristol Royal Infirmary Inquiry heard how the parents of Melissa Clarke found out after she died that Mr Janardhan Dhasmana had performed a senning operation when he had told them he was doing a switch.

By 1991, when Melissa had her operation, most heart units only used the senning procedure if there were complications that made the switch unsuitable.

When the BRI did use the switch method it had a far higher death rate among patients than the national average.

Mr Wisheart only ever carried out two switch operations. One patient lived and the other died.

But between 1990 and August 1994, he performed 21 sennings, with only one death.

Technical hitch

Dr Chris Monk, talking to the BBC in 1995, explained why the senning had become outmoded.

"Unfortunately long term the wrong ventrical is pumping blood the wrong way around the body, and therefore it starts to fail," he said.

Mr Ash Pawade may have to perform risky corrective surgery

"But that doesn't occur until many many years later. So you have an operation that seems to be very successful to correct the problem but twenty of thirty years down the line has got a technical hitch."

Some of the 20 who survived could now need heart transplants or an extremely risky procedure to correct the earlier work.

Mr Ash Pawade, who now runs the BRI's paediatric heart unit, said: "It is a risky operation.

"But the more you do the better you' ll get at it. Unfortunately the numbers will be very small � and will have to be concentrated in a few centres."

When asked to rate the difficulty of the operation on a scale of one to 10, he gave it nine.

Evidence for larger centres

On Thursday the BRI inquiry heard from Dr Michael Godman, president of the British paediatric Cardiac Association, that the unit was not doing enough heart operations to maintain its expertise.

He produced evidence that the best surgery results are obtained on children under one when the centre undertakes 250 to 300 procedures a year.

In 1986-1987, the BRI performed 65 such heart operations.

As one of the UK's nine supra-regional heart centres, it should have performed many more.

Dr Godman said the BRI carried out far fewer heart operations than other specialist UK centres.

For instance, While the Leeds centre carried out 150 closed heart operations in 1986-1987, Bristol carried out 45.

And Bristol's 20 open heart operations in that time compares badly to the Liverpool centre's 126.

Calls for audit

Dr Godman said: "There isn't much evidence but there is a general belief that bigger is better.

"Smaller centres cannot achieve comparable results - even with good surgeons."

Dr Godman said there were repeated calls for better audit of paediatric heart surgery during the 1980s.

But these were ignored, he said, and little was done to assess the work of different hospitals.

Dr Godman added that the problem of competence at the switch operation was an international one.

He said: "There were surgeons world-wide who, in the arterial switch operation could have probably benefited from more experienced colleagues who had already adopted the procedure as part of their established operations."