A procedure to drain ovarian cysts without the need for surgery could help more women avoid serious pain and complications of endometriosis without harming their fertility, new research has shown.

Endometriosis, a condition where the cells lining the uterus grow elsewhere in the reproductive organs, affects about one woman in 10 and can cause ovarian cysts (endometriomas), debilitating pelvic pain and bleeding. Surgery to remove these cysts can require removal of parts of the ovaries, which can result in infertility.

Draining the thick fluid with a syringe is often ineffective but doctors from Yonsei University College of Medicine in Seoul have now pioneered a new approach with a catheter to clear and treat it.

”Endometrial cyst content can be incredibly thick and sticky,” said Professor Man-Deuk Kim, one of the authors of the study published in the journal, Radiology. “A 16-gauge or 18-gauge needle is sometimes not large enough to completely evacuate the cyst.”

This can mean that women are left in pain and may have to opt for surgery as a second resort, as well as increasing the risk of inadvertent punctures which can cause complications.

In a small trial of 14 women, the cysts had shrunk shrank to one-fifth of their size on average after a year. Even complex cysts with multiple chambers – which can end-up re-growing if not properly removed – could be treated.

This is an advantage of the more robust catheter method which means it can break down the internal walls before treating with a solution of 95 per cent ethanol.

Professor Kim said: “In our study, the recurrence rate of catheter-directed sclerotherapy was zero percent, which is very encouraging given that endometriomas measuring up to 13.5cm in diameter or those that had internal septation (multiple chambers) were included in the study.”

He added: “I hope our catheter-directed sclerotherapy will help women avoid surgery while maintaining ovarian reserve and fertility.”