Dear doctor can i do a semen analysis before doing a surgery on the vericoceles to see if it affects fertility and avoid surgery?

Certainly: If you don't have a low sperm count (oligospermia), then you do not need to undergo varicocelectomy, unless it is being done in the treatment of testicular discomfort.

Yes and no: I recommend a baseline analysis before surgery but many men with varicoceles see a progressive decline in semen quality if they don't get repaired. Therefore, you can't predict if you'll be ok without surgery.