London - Patches made from human placenta could prevent men becoming impotent following prostate cancer surgery.
The patches are wrapped around key nerves before the cancer is removed to prevent incontinence and erectile dysfunction, which can occur in up to seven in ten men undergoing the surgery.
Pilot studies suggest that growth hormones and other repair cells in the tissue, donated by mothers having Caesarean deliveries, protect the nerves and aid recovery after surgery.
Around 40 000 men are diagnosed with prostate cancer every year. The most common treatment is a radical prostatectomy, which involves surgically removing the prostate gland, which sits between the bladder and the penis.
While the surgery has a good success rate - up to 80 percent of men who undergo it are alive ten years later - as many as 20 percent of men experience incontinence afterwards, while up to 70 percent have erection difficulties.
The challenge for surgeons is that the area around the prostate is a forest of nerves - including the cavernous nerves, which help trigger erections, and others involved in bladder control. Problems occur if these become damaged during the operation or by scarring and inflammation.
Surgeons hope to protect the nerves by wrapping them in human amniotic membrane or amnion, a thick membrane that forms the innermost placenta layer.
Amnion is tough and flexible and contains a cocktail of compounds, including growth factors (proteins that stimulate the growth of cells), immune system cells and mesenchymal amniotic cells - the latter are stem cells, or master cells, that can form other kinds of tissue.
Animal studies have also shown that it has nerve-protecting effects. One, reported in the Journal of Immunology Research, showed that amnion cells could stop inflammation - a cause of scarring - and trigger the recovery of damaged nerves in mice with multiple sclerosis.
In the new trial at the Lukas Hospital in Neuss, Germany, 30 men undergoing surgery for localised prostate cancer will first have amnion patches - which have been sterilised and dried - wrapped around those key nerves. Once in place, the sheets become moist and stick to the tissue without the need for stitches.
Results from a previous small trial show that it can be highly effective. At first follow-up after six weeks, 41 percent of men who had the patch were able to sustain an erection compared to five percent in men who did not have the patch, according to the results reported at the World Congress of Endourology in Taiwan.
Professor Raj Persad, a consultant urologist at Bristol Urology Associates, said: "Use of amniotic membrane will need to be subjected to larger-scale trials before wide acceptance will be possible.
"It is possible however - as sounds to be the case - that the anti-inflammatory and anti-scarring effects may lead to better functional outcomes, together with the 'rejuvenating' stem cell effect for delicate nerve and blood vessel tissues."