The scientists carried out the operation on 173 infertile men, and on average, found the men's sperm motility and count had improved within three months.
So-called gut motility is also believed to have an impact on other body systems and could protect patients from other illnesses while they are recovering, the hospital said.
Keeping a mobile phone close to the testes, they found, had a significant negative impact on sperm numbers and motility, though they do not speculate why that might be.