A neurosurgeon has been asked to apologise after cutting into the wrong part of a patient's skull.
The incident, which happened in 2015, has been detailed in a report released today by Health and Disability Commissioner Anthony Hill.
The report described how a man underwent neurosurgery to remove a tumour from his brain.
The surgical site was identified using a guidance machine and markings on the man's skin.
Once the initial incision was made, it became apparent that the guidance machine was inaccurate and the incision had not been made in the correct location. The skin markings had washed off and could not be used as a guide.
The neurosurgeon extended the bone opening into what he thought would be the correct area.
However, it became apparent that the opening had been made in the wrong place of the man's skull at which point the operation was stopped.
Further attempts to remove the tumour were considered to be too risky.
Hill accepted clinical advice that while any neurosurgeon could make this error it was still unacceptable.
There were known risks with this complex surgery, but Hill considered that the neurosurgeon should have undertaken further checks and challenged his own assumptions about the correct location before extending the incision.
Hill found the neurosurgeon had breached the Code of Health and Disability Services Consumers' Rights, and recommended that an apology be given to the family of the man, who had since died from cancer.
He also asked that the DHB use the case as a lesson so it wouldn't happen again.
"Taking the time to undertake any checks available to ascertain that the surgeon is in the right place before proceeding with such surgery is paramount."
In the independent expert advice he offered the inquiry, neurosurgeon Dr Agadha Wickremesekera said while the standard if care for the process had been satisfactory, the surgeon's error had been a "departure from the accepted standards.
"Such an error can be made infrequently. As in this case all neurosurgeons use anatomical landmarks as well as the assistance of the neuronavigation," Wickremesekera said.
"During the opening of the dura one could in retrospect suggest that the surface anatomy of the occipital lobes should have been recognised, as well as the sagittal sinus.
"Unfortunately this did not occur and in terms of the practical outcome there has been a departure of an accepted standard."