PESA stands for Percutaneous Epididymal Sperm Aspiration. It is normally performed under sedation or general anaesthetic as a day case procedure.

It involves a small needle being placed in to the epididymis and the fluid withdrawn.

The specimen can normally be analysed during the same anaesthetic under a microscope to determine if there are any suitable sperm. 

If there are no suitable sperm then testicular sperm extraction can then be performed (TeSE).

Most men with an obstructive cause for their infertility will have sperm retrieved successfully with PESA or closed TeSE. 

TeSE is explained in more detail in the TeSE information.