Sperm harvesting is entirely different from a diagnostic testicular biopsy because, in this setting, the goal is not to identify what is happening in the testis but instead it is to find sperm. Only men with no sperm in their ejaculate (azoospermia) need to have sperm retrieved directly from the testis or epididymis.
This may involve a simple aspiration for men who have a blockage or require much more extensive sampling of the testis for men who have a sperm production problem. As a result, there is a significant difference in the amount of time it takes, the need for anesthesia and the equipment utilized.