Hi there. My husband has had sperm retrieval in the Czech Republic at Gennet clinic. The invasiveness of the procedure and the pain afterwards depend on the type of azoospermia the man has -obstructive or non obstructive. If it's obstructive, spermatogenesis is usually not impaired and enough sperm can be retrieved with 2-3 incisions. If it's non-obstructive, spermatogenesis may be problematic and more incisions may be necessary in order to find sperm.
I strongly encourage you to discuss the procedure beforehand with the surgeon urologist. He should be able to tell you how he operates, if an embryologist is present on site to check the samples as they are taken, so they know when they have enough and can close, etc. In my opinion, it is essential that they check the samples, not all clinics provide this opportunity and there are doctors who take a fixed number of samples, even if fewer would be enough if they checked each sample after retrieval.
My husband had 2 incisions on the right testicle, one on the epidydymus (aspiration) and one on the testicle (sperm tissue extraction). He had local anesthesia and was put to sleep for about 10 minutes. He was back in the room in 30 minutes.
After 2 hours he felt some pain, but he stared taking 400 mg Ibuprofen every 4-5 hours and he was ok. If your husband tolerates pessaries, there are ketoprofen/ ibuprofen pessaries and they do the job in a few minutes.
The pain is bearable and the patient can walk, sit, eat, although there is some discomfort. The doctor told us that the pain is the same even if he makes more incisions. It goes away in a few days, be prepared and have ibuprofen and paracetamol on hand.
Good luck!
