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Twelve New Zealand women have suffered severe reactions to a dye used during breast surgery to predict the possible spread of cancer, raising questions over its continued use.
Breast surgeon Ros Pochin, of North Shore Hospital in Auckland, told a conference yesterday that women given the patent blue dye had experienced blood-pressure problems, allergic reactions and a heart attack.
Patent blue has a range of uses, including colouring carpet, as well as in medicine.
In breast cancer surgery, it is commonly used - alongside a radioactive tracer tracked with an external probe - to determine the likely drainage paths from a tumour to the lymph nodes of the adjacent armpit.
Only the nodes to which the dye or tracer travel are removed. In this way, many fewer nodes are removed than previously, reducing complications including arm-swelling.
Mrs Pochin told the Australasian College of Surgeons' scientific congress in Christchurch that surgeons who responded to her question-naires reported 12 minor reactions, including rash and blistering.
"There were 12 major reactions including hypotension [low blood-pressure] and anaphylaxis [a life-threatening allergic reaction]. There was one myocardial infarct [heart attack] and two patients requiring CPR. There were no deaths."
All the major reactions were in high-volume Auckland centres.
"Patent blue isn't licensed. The surgeon is completely liable; the drug company is not liable."
Mrs Pochin also asked surgeons what they thought was the incidence of adverse reactions to the blue dye, and their replies ranged from one in 200 to one in 100,000.
Internationally the rate was about 2 per cent.
She said some surgeons used just patent blue, some just the radioactive tracer.
"Should we be changing the blue dye or omitting it because of the risk?" she asked, although she added that the alternatives also carried the risk of bad side-effects.
She called for research comparing the techniques, a comprehensive system of adverse-reaction reporting and consideration of skin testing to detect patients at risk.
