Microscopic epididymal sperm aspiration (MESA) is a technique used for the retrieval of sperm for males experiencing azoospermia, or an absence of living sperm in their semen. This condition is common in men with a blocked or no vas deferens, a testicular duct that carries sperm to the penis.  It may also be indicated for men who have had a vasectomy.

This procedure is performed by urological specialists trained in the field of male infertility. Often, one retrieval yields enough sperm to have some cryopreserved. Your physician will discuss any minor risks of the procedure with you in detail.