Surgical retrieval of spermatozoa
SURGICAL RETRIEVAL OF SPERMATOZOA
(FNA/PESA, MESA, TESE)
Azoospermia can be defined as obstructive and non-obstructive (or secretory) depending on whether the absence of spermatozoa in the ejaculate is caused respectively by an obstruction of the deferent ducts or by a primary or secondary alteration of spermatogenesis.
Obstructive azoospermia can be:
- post-surgical (vasectomy)
- congenital (bilateral absence of deferent vessels)
In all these cases the spermatogenesis is preserved and it is therefore possible to recover spermatozoa surgically.
Secretory azoospermia may be due to:
- testicular trauma or torsion
- radio or chemiotherapy
- chromosomal abnormalities (47,xxy Klinefelter syndrome, 47,xyy syndrome, 46,xy del,yq11)
- unknown genetic causes
According to the histological picture they are distinguished in:
- sertoli cell syndrome only
- maturative arrest
The chances of finding surgically mature spermatozoa is closely related to the histological picture.
In clinical practice, various surgical techniques have been introduced for the recovery of spermatozoa from epididymis and/or testicles (MESA, PESA, TESE, FNA).
FNA/PESA-MESA (Percutaneous Testicular/Epididimary Sperm Suction; Epididimary Microsurgical Sperm Collection)
These techniques may be used for those patients in whom sperm production by the testicles is normal, but their emission by ejaculation is prevented by an obstruction that can be located at various levels of the seminal tract. They consist in aspirating, after local anaesthesia, the spermatozoa transcutaneously at the testicular or epididymis level by a simple intravenous infusion needle. Sperm retrieval can also be performed by microsurgical procedure (MESA). The spermatozoa thus recovered can be processed and used for fertilisation using the ICSI technique.
TESE (Testicular Sperm Extraction)
TESE consists in an extraction of very small fragments of testicular tissue from one or both testicles. This operation can be performed under local anesthesia. This technique is indicated in case of obstructive azoospermia when percutaneous aspiration (TESA/PESA) fails (or is not convenient) or in case of secretory azoospermia. Any recovered spermatozoa may be used for cryopreservation and/or fertilisation using the ICSI technique.