Percutaneous Epididymal Sperm Aspiration
Sperm retrieval techniques
are used to remove sperm from the testes or from the epididymis where there is an obstruction, a congenital absence of the vas deferens, insufficient sperm production, or in the case where vasectomy reversal fails. In percutaneous epididymal sperm aspiration, referred to by its easier to say acronym, PESA, a doctor penetrates the scrotum and epididymis with a needle. He then draws out the sperm into a syringe. The sperm retrieved by any of the common sperm retrieval techniques: MESA, PESA, and TESE, can be used in fertility treatments such as in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI).
The PESA procedure is an easy one to perform. In most cases, the procedure is done without any need for anesthesia. In general, the epididym's form makes it easy to locate and penetrate, which makes the procedure even more effortless to perform.
To perform PESA, the physician takes the testicle between his index, middle, and thumb fingers while the other hand palpates the epididym to identify its head. A needle connected to a small syringe is inserted perpendicular to the scrotal skin, which creates negative pressure. The physician knows the needle is in the right place if there is an immediate entry into the syringe of a small amount of fluid. The needle is then removed and the fluid brought to a laboratory.
At the laboratory, the fluid is placed in a Petri dish which contains culture medium. The needle is washed several times with the same medium. Next, a small drop of this material is examined for the presence or absence of mobile sperm. The lab is then in touch with the doctor to tell him the results of the exam.
The sperm concentration in the epididymal fluid is very high. There may be up to 200 million sperm in the most minimal amount of fluid. Even if the physician is only able to aspirate the smallest amount of fluid, there may be enough motile sperm for an ICSI procedure.
If the lab exam fails to find enough healthy sperm for an ICSI procedure, the physician performs another aspiration at the same site or on the other side of the epididymis. On the other hand, if the aspiration provides more than enough sperm for immediate use, the excess can be frozen for use in future cycles of ICSI. This means that the patient can avoid having to undergo a second PESA procedure.
The patient is free to return to his normal work schedule or daily activities once the procedure is finished. Should PESA fail to produce results, testicular sperm aspiration (TESA), or a small biopsy of the testicles (TESE) in which sperm are obtained from testicular tissue, may be indicated.