Six-inch metal forceps were left inside a patient following surgery at a Worcestershire hospital.
Worcestershire Acute Hospitals NHS Trust has apologised for the “exceptionally rare” incident which occurred at Redditch’s Alexandra Hospital, with an investigation now underway.
The error happened during a seven-hour abdominal procedure on 23 November, according to the BBC.
The forceps had to be located using an x-ray while the patient was still under anaesthetic.
But they could not immediately be removed, and the patient had to be moved to intensive care overnight before an operation the following day.
Any investigation into what the NHS term a “never event” will now have to establish how the forceps came to be overlooked.
The trust said there are “clear and well-established processes” in place to prevent this type of incident happening.
Usually, all instruments are counted and checked before the patient is closed up, with a further audit at the end of surgery.
Trust chief executive Matthew Hopkins said: “We are aware of an incident which involved a surgical instrument being left inside a patient following surgery.
“There are clear and well-established processes in place to protect patients from this kind of event, which are exceptionally rare.
“We are currently carrying out an investigation into what happened.
“The patient and their family have been informed as part of our duty of candour.
“We have apologised unreservedly to the patient and promised to share the findings of our investigation with them once it is completed.”