For 17 years something as simple as a whiff of perfume or fresh coffee could fill Trina Liggins' nostrils with an overwhelming putrid, nauseating stench.

The Dunedin woman has been stricken by what appeared to be a mystery medical condition, later identified as phantosmia, that when it strikes each day makes everything she smells overpoweringly rotten.

But yesterday she became the first New Zealander - and one of an estimated six people worldwide - to undergo ground-breaking surgery that should repair her sense of smell.

Wakefield Hospital sinus specialist Simon Robinson cut smell fibres leading from the olfactory bulb at the base of Ms Liggins' brain to the affected right side of her nose, blocking half of her sense of smell. Her functioning left side of her nose should continue to work normally.

The endoscopic surgery, performed using a narrow telescope, carried a risk of damage to the brain or causing leakage of the brain fluid around each fibre, but Dr Robinson said last night that it had gone very well.

Speaking just before the operation, Ms Liggins said getting her sense of smell back would be worth much more to her than winning Lotto.

"I can't imagine life with a normal sense of smell, it will be awesome."

Top of her list to taste without fear of encountering a foul smell is a strong cup of coffee and chocolate.

Phantosmia has blighted the 35-year-old graphic designer's life since she was 18. The condition developed suddenly and it took several years and her own detective work on the internet before she was able to give it a name and seek a possible treatment.

The condition was not constant, but when her symptoms were active even the sweetest smell became vile.

"The neurones in my nose are picking up smells wrong. Things that should smell nice smell blimmin' awful - even fresh air, water, everything.

" It certainly puts you off your food."

The symptoms struck several times a day, often when she was heading out for dinner or going to the movies, sending her rushing back home.

There is a high suicide rate for phantosmia sufferers and Ms Liggins said although she had not felt suicidal, the condition had driven her to "complete and utter frustration and hopelessness".

"I could understand how people could come to the end of their tether."

A few months ago, Ms Liggins learned from her ear, nose and throat specialist at Dunedin Hospital that Dr Robinson could perform an operation that might help her smell again.

"It's fantastic. At first I thought I'd have to travel to America and have very, very costly surgery. I couldn't believe that somebody here could do it."

The surgery at Wakefield Hospital, which costs about $17,000, is covered by the Health Ministry.

Dr Robinson was "extremely hopeful" the surgery would work because there were no other treatment options available for Ms Liggins' "oppressive and insidious condition".

The outcome would not be known for a few weeks.

Yesterday was the first time he performed this type of operation after learning it from Australian sinus specialist Peter John Wormald and its pioneer, American Don Leopold.