The BBC's Robert Parsons on the brain operation

Doctors at the St Petersburg Institute of the Human Brain say their technique is cheap and has an 80% success rate.

The operation involves drilling holes into the brain and removing tiny parts of the brain which they claim govern drug addiction.

So far the surgeons have tried the technique out on more than 100 patients.

Their high success rates mean the technique could soon attract worldwide interest.

Radical breakthrough

Professor Svyatoslav Medvedev, who leads the Institute's team, says the operation is a radical breakthrough in the treatment of heroin addicts.

"I don't know any other methods which can successfully remove this psychological dependency.

Professor Svyatoslav Medvedev: claims 80% success rate

"During the operation we have full cooperation and full voice contact with patients. We never use general anaesthetic, only local anaesthetic."

The ability to communicate with patients during the operation is intended to help ensure surgeons do not damage other vital parts of the brain.

Working slowly, they use waifer-thin needles to probe brain tissue as well as a compressor adapted from a car foot pump.

The surgeons do not boast that the treatment is a miracle cure.

They say if patients return to drugs their addiction may come back. Also, they cannot control the social environment in which patients live.

Drug problems

St Petersburg faces huge economic problems and drug use there is out of control.

Last year, two tonnes of heroin were found in port of St Petersburg.

But several former patients back the operation. Sveta says she feels like a new woman two months after she went to the Institute.