Carmen Walker and her husband, Bob. Carmen died after a cancer procedure at Waikato Hospital in 2010. Photo: LDR / Supplied
The family of Carmen Walker - who died following complications during a procedure at Waikato Hospital - say the coroner should correct a mistake in his findings.
But Coroner Alexander Ho said he can not change his 19 September findings into the cause of Walker's death in August 2010, because he no longer has jurisdiction.
Walker was 78 when she underwent an isolated limb infusion (ILI) at Waikato Hospital to treat melanoma spreading from the Whanganui woman's right ankle up her leg.
The treatment involves injecting a high dose of chemotherapy (melphalan) into the leg to target the cancer cells, before being washed out along with tainted blood.
The blood in her leg and the melphalan was isolated from the rest of the body by a tourniquet, but after the tourniquet was lifted, Walker suffered a cardiac arrest and died in the intensive care unit later that night.
The controversial case was only heard at inquest last year, 13 years after Walker's death, because the pathologist who conducted her post mortem changed his finding into the cause of death prompting a new coronial inquiry.
Coroner Ho found she died due to complications during the treatment including an adverse reaction to protamine, a drug that reverses the effects of heparin, a blood-thinning drug used to prevent blood clots.
He found Walker's circulating blood volume was not accidentally drained out of her leg as part of the procedure, and massive blood loss was likely from a combination of other internal and external bleeding.
"Nonetheless, I observe that, for procedures involving some element of blood drainage, it would be prudent to drain it into a measurable container," Coroner Ho wrote.
Walker needed transfusions of twice her usual circulating blood volume during the 90-minute resuscitation shortly after fluid was drained from her leg into a bucket that did not have a measuring system.
Coroner Ho found the surgeon leading Walker's procedure - who has since applied for permanent name suppression - and the lead anaesthetist did everything they could during the resuscitation and Walker died in spite of their efforts.
Plastic surgeon Dr Adam Greenbaum, who was observing that day, has always claimed there was too much blood in the bucket.
Greenbaum said the coroner erred when he found that ILIs were no longer performed in New Zealand, and based on that he made no formal recommendations to prevent further deaths.
RNZ confirmed ILIs are still performed in public in Auckland.
The coroner said he made that finding based on evidence during the inquest.
Walker's sons Craig and Lance said they were devastated by the findings because they believed human error was to blame and their mother's death was preventable.
They said they had fought for 14 years to uncover the truth of what happened, particularly for their father Bob who died several years after his wife of 50 years, not knowing what really happened.
Last month the brothers lodged a memo with the Coroner's Court asking that Coroner Ho:
- Correct the mistake about ILI procedures not being performed in NZ and make formal recommendations;
- Address the evidence against protamine as the main cause of the complications;
- Address why he disagrees that a catastrophic blood loss happened after the procedure and not during it which they say is evidenced in witness testimony.
But in a minute sent to the parties on 31 October, Coroner Ho said having issued his findings and signed a certificate of findings he had become "functus officio".
"I have exhausted my jurisdiction and have no further power to adjudicate (or re-open adjudication) on the substantive matters canvassed in the findings.
"This is a basic legal principle reflecting the public interest in decision-making finality.
"If any party considers that I have erred in reaching the conclusions that I did, the law provides appropriate avenues for these to be ventilated. The Court is not one of those avenues."
The family can apply for a judicial review in the High Court but that does not usually involve a judge deciding whether the finding was right and instead the judge looks at whether the way the decision was made was in accordance with the law.
Craig Walker said he had not spoken to his brother Lance about the outcome yet, because he was based in the United Kingdom, but they previously did not want to pursue a judicial review.
"I think we've gone as far as we can go to be perfectly honest. Whether it's worth pursuing it anymore I really don't know."
Greenbaum criticised the coronial system as not fit-for-purpose.
"Despite the findings the coroner signed off containing significant factual errors that demonstrate the purpose of the inquest, as described by the coroner, hasn't been achieved, there is no mechanism to change the findings - even if the coroner wanted to do so - within the current legislative framework that governs the coronial system."