Te Whatu Ora in Auckland has been found in breach of health regulations after surgical equipment was left in a woman's abdomen after surgery.

The woman had experienced severe pains in her abdomen after a C-section at Auckland City Hospital.

A CT scan found the dinner plate-sized instrument in her abdomen 18 months after her surgery.

The instrument itself was an Alexis wound retractor (AWR), a soft tubal instrument used for holding open surgical wounds.

The woman had visited her GP several times, as well as the emergency department at the hospital, prior to the AWR being found.

The Health and Disability Commissioner found the health board had breached the consumers rights code, which give every patient the right to have services provided with reasonable care and skill.

Te Whatu Ora in Auckland told the commission the process for ensuring all surgical tools were accounted for following surgery was laid out in its Count Policy.

However, at the time of the woman's surgery, AWRs were not included as part of the policy.

Commissioner Morag McDowell said the Count Policy did not provide sufficient guidance for staff to determine which instruments should be included in the count.

It instead relied on staff applying their own interpretation of what instruments were "at risk of being retained".

She recommended Te Whatu Ora write to the woman to apologise, and offer the opportunity to meet face-to-face.

"As set out in my report, the care fell significantly below the appropriate standard in this case and resulted in a prolonged period of distress for the woman," McDowell said.

"Systems should have been in place to prevent this from occurring."

McDowell also recommended Te Whatu Ora confirm a directive to include AWRs as part of the surgical count.

Te Whatu Ora in Auckland was also referred to the Director of Proceedings to determine whether further proceedings should be taken.

This story was originally published by RNZ