Percutaneous Epididymal Testicular Aspiration (PESA) is similar to TESA in involving the use of needle-syringe aspiration system, but the aspiration of testicular fluid is performed directly from the epididymis (a coiled tube at the back of the testes).
This technique differs from PESE in the fact that it does not require surgical scrotal exploration, and, if successful in isolating a sperm-rich epididymal fluid, it can be repeated easily.
The sperms isolated from the epididymal fluid have undergone maturation, which means that they are able to swim and fertilize an egg. Depending on the amount, quality of sperms isolated and your underlying condition for PESA, your doctor will decide whether your case would require IVF with or without ICSI. However, due to the low number of sperms usually recovered in these cases, eggs are fertilized with ICSI.
PESA is performed under local anesthesia. A needle is gently inserted in the epididymis through the scrotal stretched skin and withdrawn gently until fluid containing sperm is entering the tube of the aspiration system. Several piercings to both epididymal areas of testicles are performed until the surgeon has collected sufficient amount of fluid for sperm isolation.
After recovery, you will feel some numbness and pain, but full recovery can be achieved within 24-48 hours (the scrotum being one of the fastest healing parts of the human body).
The collected testicular samples are examined under a microscope and individual sperms are extracted by one of our technologists. PESA can be coordinated to happen at the same day as the maternal egg collection, so that IVF with ICSI can be performed with freshly-isolated testicular sperm. However, if sufficient amounts of good quality sperms are recovered by PESA, then they can be frozen down for a future IVF with ICSI cycle. Epididymal sperms have been reported* to recover thawing better than testicular sperms.
TESE, PESE, TESA or PESA can benefit men that have obstructive or non-obstructive azoospermia.
In obstructive azoospermia, in the majority of cases, sperms are produced normally in the testes, but due to absence or blockage of the ejaculatory-mechanism tube (or vas deferens as it is called), they are not released in the semen. In that case, immature sperm can be collected from the testes or the epididymis
Men with minor vas deferens blockages may be subjected to TESA or PESA. Most difficult cases though will be subjected to TESE or PESE, in addition to unsuccessful attempts of TESA or PESA.
For instance, men that have a previous vasectomy will have disrupted communication between testicular sperm production and ejaculation. In cases that this procedure cannot be reversed, due to a damaged vas deferens, all individual parameters will be considered, and one of the testicular sperm recovery methods will be employed.
Also, testicular sperm recovery methods benefit men with a genetic condition, such as cystic fibrosis, for instance. Cystic fibrosis is an inherited pulmonary disease that affects the development of the reproductive system in men. Almost 95% of men with cystic fibrosis do not develop all or parts of the vas deferens and epididymis. In 90% of these men, sperm production in the testes is normal. However, following ICSI in such cases, embryos inheriting the defected cystic fibrosis genetic material are detected and excluded with the use of Preimplantation Genetic Diagnosis (PGD) and / or Preimplanation Genetic Screening (PGS).
Other causes of obstructive azoospermia include excessive scarring form a previous sexually transmitted disease, or congenital cysts that may block the vas deferens.
In non-obstructive azoospermia, there is a defected production of sperm due to a pre-testicular or testicular cause. In these cases, the ejaculatory mechanism is fully functional.
Pre-testicular causes of non-obstructive azoospermia include disruption of hormones that are responsible for sperm development and production. For instance, inadequate Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH) production. In some cases, the problem may lie within the major hormone-producing organ, the pituitary in the brain, or within the thyroid glands (for instance, with hyperthyroidism).
Testicular causes of non-obstructive azoospermia include undescended testicles (a condition in which one or both of the testicles have not resumed their proper position in the scrotum), testicular cancer, or genetic syndromes that affect sperm development and production.
For cases of non-treatable non-obstructive azoospermia, testicular sperm recovery methods, mainly TESA for mild cases, and TESE for more severe cases, give hope as limited sperms may be found in the testes.
Your treating doctor will assess your individual circumstances, as well as the severity of your case before deciding which of the above testicular sperm recovery methods is suitable for you. A consultation including a full explanation of the reasons for your doctor’s choice will be provided.
The next step after a successful testicular sperm recovery is IVF with ICSI. This assisted reproductive technique is now routinely used (in more than 90% of cases), and about 70-85% of the eggs injected with sperm in ICSI become fertilized, regardless the source of the sperms (ejaculate, epididymis, or testicles).
As long as sufficient and good quality sperms, either from testes or epididymides (plural of epididymis), are isolated, the chances of a successful IVF with ICSI are high. Other parameters that may affect this outcome include paternal and / or maternal chromosomal integrity, as well as the quality of eggs and maternal age.
If testicular sperm recovery followed by IVF with ICSI is not successful, our specialist doctors will provide you with a comprehensive consultation for all other available / applicable options, and with explanations, where possible, for the reasons behind a negative outcome.
Reference
* Shin DH, Turek PJ (2013). Sperm retrieval techniques. Nat Rev Urol. 10(12): 723-30. (Pubmed; PMID: 24296703)