Talk to Urologist on Testicle Pain

AOA doctors. my husband used to have pain in his testicles. He went to the urologist and he told him that there are swelled veins in the left testicle that are stopping blood to pass. He has given medicines for one month and if it doesn't work, then he will do the surgery. But the success rate in surgery is only 15%. I want to ask the doctors about the reason for this and can this be cured with medicines, if we don't wanna go for surgery and can this effect the fertility ratio or not.