Sperm can be recovered directly from the testes either by needle aspiration (FNA) from the testis or epididymis, or via a surgical biopsy of small testicular pieces (TESE).
Surgical sperm recovery is recommended in cases of azoospermia, inability to collect a semen sample on the day of egg collection or failure of electroejaculation. The procedure can be performed on the day of the egg collection under intravenous or local analgesia. The testicular tissue excised is processed by the embryologist in order to retrieve any sperm. Once motile sperm have been isolated, the mature eggs can be fertilized using intracytoplasmic sperm injection (ICSI). Any excess motile sperm can be cryopreserved for future use.
There are various methods or surgical sperm retrieval, either from the epididymis or from the testes.
Sperm retrieval from the epididymis
- Microsurgical epididymal sperm aspiration (MESA):
It is recommended in cases of obstractive azoospermia with normal spermatogenesis. The epididymis is surgically opened with the use of a microscope and its fluid is aspirated so that sperm can be retrieved. - Percutaneous epididymal sperm aspiration (PESA):
It is recommended in case of obstractive azoospermia with normal spermatogenesis. A 19-21G needle is passed into the epididymis and then fluid is gently aspirated.
Sperm retrieval from the testes
- Fine needle aspiration (FNA):
It is recommended in cases of obstractive azoospermia with normal spermatogenesis. A 21G needle is passed through the testis. - Testicular sperm aspiration (TESA):
It is recommended in cases of obstractive azoospermia with normal spermatogenesis. - Testis biopsy (testicular sperm extraction – TESE):
It is recommended in case of both obstractive and non-obstractive azoospermia and it includes performing an open biopsy and excising small pieces of testicular tissue.
The sperm aspiration methods from the epididymis (MESA, PESA) or the testes (TESA) are simple, but are usually "blindly" performed and can cause testicular tissue damage such as haematoma, cysts and testicular atrophy. Testicular biopsy (TESE) is suggested by international scientific literature as the more effective method of sperm retrieval and it is associated with fewer complications. For this reason, in our Unit, the surgical sperm retrieval is performed by testicular biopsy (TESE) by specialized surgeons.
The procedure takes place on the day of egg collection with intravenous or local anaesthesia. The small testicular tissue pieces are processed by the embryologist in order to retrieve any sperm. Following the retrieval of sperm, ICSI can be performed. Any excess sperm can be cryopreserved for future use so that there is no need to perform another biopsy.
Testicular biopsy for diagnostic purposes
Testicular biopsy prior to the day of egg collection is not recommended. Our Unit is in line with this recommendation since according to the scientific literature such a biopsy constitutes an extra surgical procedure that causes extra damage to the testicular tissue and sperm retrieval on the day of the biopsy for diagnostic purposes cannot guarantee that sperm will also be retrieved on the day of egg collection.
Testicular biopsy for diagnostic purposes and the histological evaluation that follows is mainly performed for the assessment of spermatogenesis. The histological evaluation can also be performed on the testicular pieces that are excised on the day of the egg collection.
