YOUNG women with a painful gynaecological disorder that can leave them infertile are facing a postcode lottery over access to a "safe and rapid" treatment invented in Scotland.

Only six hospitals in Scotland currently offer patients with endometriosis the opportunity to undergo a procedure known as laparoscopic helium ablation (LHA) despite the backing of gynaecologists and evidence that it can eliminate symptoms. The operation is performed using an award-winning instrument called a Helica Thermal Coagulator, which was created by Edinburgh engineer Maurice Howieson in 1993 and first trialled in Glasgow as a treatment for mild to moderate endometriosis.

The condition mostly affects women aged between 25 and 40 and is caused when cells like the ones in the lining of the womb spread to other parts of the body, sometimes covering neighbouring organs such as the bowel or bladder and acting like "miniature wombs". The condition affects more than 150,000 women in Scotland and symptoms include extreme abdominal pain, fatigue, painful or heavy periods and difficulty conceiving.

Most patients mask symptoms with painkillers and hormone pills but many eventually resort to a hysterectomy or laparoscopy - also known as keyhole surgery - which uses lasers to burn off the problem cells. However, this cannot be performed close to sensitive organs, such as the bladder or bowel, which are often the main source of patients' pain.

In comparison, the LHA-Helica procedure uses very low electrical power combined with helium to produce a plasma beam that can safely and accurately remove endometriosis build-up from all areas, including vital organs.

It was discovered by chance as a treatment for endometriosis after Mr Howieson, now 69, first devised the Helica as a machine to stop internal bleeding. However, it was seized on by Glasgow-based gynaecologist Dr Robert Hawthorn who pioneered the technique to treat patients at the former Southern General.

Mr Howieson said: "The real revelation was when we took it round all the medical specialities and one guy [Hawthorn] said 'I know what this will be good for' - and it was endometriosis. That was a lifeline. He became quite good at it and tended to get all the difficult cases."

The Helica device scooped the prestigious John Logie Baird award for innovation in 1997 and Dr Hawthorn praised it in research as a "very encouraging" instrument which was "simple to use, easily maintained and is significantly cheaper" than similar lasers, with comparable success rates.

A 2005 study in US journal 'Fertility and Sterility' found that more than 87 per cent of patients had reversed or improved symptoms six months after treatment, while a study carried out at Pinderfields Hospital in Yorkshire found that 20 per cent of those treated for endometriosis and infertility conceived within six months of LHA.

Yet despite being used to treat some 50,000 patients, it is still comparatively unknown and NHS Greater Glasgow and Clyde remains one of only five health boards in Scotland - along with Lanarkshire, Forth Valley, Lothian and Tayside - to offer the treatment. Most Helica machines are sold to hospitals in England.

Mr Howieson said this left many GPs prescribing drugs instead.

He said: "In lots of places where they've adopted the Helica, the GPs now know that they can refer patients right away. But I have personal friends who are GPs who have never referred anyone ever - now that's statistically impossible.

"So there's no endometriosis in the Borders and loads in Glasgow?"

However, Professor Andrew Horne, spokesman for the Royal College of Obstetricians and Gynaecologists, said it could not recommend LHA without approval from Nice which - although declaring the process safe - says that further research is required to support its use as standard. The Scottish Medicines Consortium has no specific guidance.

Prof Horne added: "There is evidence that removing endometriosis tissue during laparoscopic surgery, also known as keyhole surgery, can reduce painful symptoms and improve a woman's chances of having a successful pregnancy.

"Current evidence suggests there are no major safety concerns associated with [LHA] for the treatment of endometriosis. However, evidence on efficacy does not appear adequate for this procedure to be used without special arrangements for consent and for audit or research."