A man died on the operating table after doctors failed to diagnose the aneurysm that killed him soon enough.

The man was admitted to University Hospital Ayr with suspected renal colic - a type of pain experienced when urinary stones block part of the urinary tract - but then collapsed.

A consultant vascular surgeon assessed the man, identified as Mr A in an official report, and suspected he had suffered a bulge or swelling in the main blood vessel from the heart that had burst - a ruptured abdominal aortic aneurysm.

Although this was confirmed with an urgent CT scan, when Mr A was taken to theatre he died.

Mr A's wife and son-in-law complained that his condition was misdiagnosed for most of the time he was in hospital, that the hospital did not give him a CT scan to check for the aneurysm, that tragically proved lethal, before his collapse and there was a delay in performing surgery.

The Scottish Public Services Ombudsman (SPSO) took independent advice from a consultant vascular and general surgeon and found aspects of the hospital's care for Mr A to be 'unreasonable'.

The SPSO found that 'there was an unreasonable delay in carrying out a CT scan which would have identified the presence of an aneurysm'.

This lead to an unreasonable delay in the diagnosis of a ruptured aneurysm.

NHS Ayrshire and Arran has accepted that the diagnosis should have been considered earlier than it was and have assured the ombudsman that the board has taken action to prevent a similar incident happening again.

The SPSO asked NHS Ayrshire and Arran to apologise the Mr A's bereaved family for the 'unreasonable delay' of the CT scan and diagnosis.

NHS Ayrshire and Arran was also told that patients presenting with apparent renal colic should have 'differential diagnosis considered and also be considered for urgent CT scanning'.

The SPSO found that there was no delay in taking Mr A to surgery and that his initial diagnosis of renal colic 'was reasonable'.

Joanne Edwards, Director of Acute Services at NHS Ayrshire and Arran, said: "In addition to our formal apology to the family of Mr A, I can advise that we have fully accepted all the recommendations in the Scottish Public Services Ombudsman report.

"We have addressed the issues highlighted and made the appropriate changes, in terms of updating the guidance for urgent CT scan requests.

"In order to ensure learning across the organisation, we will share the findings from the report with staff, in particular with those responsible for the operational delivery of the service and with our clinical governance teams."