More than 1,100 National Health Service (NHS) patients have been victims of so-called ‘never events’ – errors so serious that they should never happen – within the last four years alone. But despite strong rules already being in place to prevent such events, managers have promised merely to “learn” from the mistakes.

A man who had his testicle removed instead of merely the cyst on it was among more than 400 patients who suffered “wrong site surgery”. One woman who had her Fallopian tubes removed instead of her appendix; another had a kidney removed instead of an ovary. Yet more have had the wrong knee, hip, eye or leg operated on, The Telegraph has reported.

A further 420 people have had foreign objects left inside them during surgery, including gauzes, swabs, drill guides, scalpel blades and needles.

‘Never events’ are mistakes which should never occur because strict guidelines are in place to prevent them. Nonetheless, over the last four years NHS England has recorded around 300 ‘never events’ on average each year. The worst offender was Colchester Hospital University NHS Foundation Trust, which recorded nine such events between April 2014 and March 2015 alone.

In some cases patients have been subjected to feeding tubes being placed into their lung instead of their gut – a mistake which can prove fatal. In others, patients have been mixed up with others, had the wrong blood given to them during a transfusion, or been given dangerously high doses of drugs.

One patient was given a biopsy on their liver instead of their pancreas, while some diabetics have not been administered insulin.

Despite the obvious danger these instances put patients in, and the long term ill effects that can result, the NHS has merely promised to “learn” from the events to ensure that they are never repeated – despite strong guidelines already being in place to prevent them.

An NHS England spokeswoman also sought to play down the figures by pointing out that they comprise a tiny percentage of cases seen by the NHS each year, saying: “there are 4.6 million hospital admissions that lead to surgical care each year and, despite stringent measures put in place, on rare occasions these incidents do occur.”

She continued: “To better understand the reasons why, in 2013 we commissioned a taskforce to investigate, leading to a new set of national standards being published last year specifically to support doctors, nurses and hospitals to prevent these mistakes.

“Any organisation that reports a serious incident is also expected to conduct its own investigation so it can learn and take action to prevent similar incidents from being repeated.”

Promises to do better will be of little comfort to the patients who suffer the ill-consequences of these mistakes.

Earlier this month the Labour Peer Lord Carter concluded that some NHS hospitals were being run on “Soviet-style models with an attitude of ‘you are lucky to have it, now wait in a queue.’”

In the worst examples of badly run hospitals, he found that management had devoted twice as much space to a bloated bureaucracy than they had to patients.

In the same week a senior cancer specialist warned that the Service was “on its knees” thanks to “thousands of health tourists” from across the European Union using the service to get free treatment.