HER4: Surgical sperm retrieval in non-obstructive azoospermic men – a randomized trial
This study is performed at the Urological Research Unit at Herlev Hospital together with the fertility clinics at Rigshospitalet and Malmø. The surgical procedures are implemented with assistance from Professor Dana Ohl from University of Michigan.
In 50% of infertile couples a male factor can be identified as a contributing cause. Azoospermia is the absence of spermatozoa in the ejaculate and is among the causes of male infertility. It is divided into obstructive azoospermia (OA) and non-obstructive azoospermia (NOA) of which the latter constitutes 60%. Obstructive azoospermia is a common cause of male infertility and can result from infection, congenital anomalies, or iatrogenic injury. In NOA the production of spermatozoa is either absent or markedly decreased.
Since 1999 microdissection testicular sperm extraction (mTESE) has become the preferred treatment option for NOA. The procedure is performed in general anesthesia using an operating microscope to carefully examine the entire testicular tissue for the presence of spermatozoa which can be used for intra-cytoplasmic sperm injection (ICSI). The advantages of mTESE include high sperm retrieval rates (SRR), around 60%, and low reported complication rates. However, mTESE is a time consuming invasive procedure requiring the right expertise, the right equipment and a proper setup of the fertility clinic. A mTESE procedure costs around 8.000 $. Therefore, mTESE is not being offered to Scandinavian men on a regular basis and until now the procedure has only been performed by a few times in Sweden and Denmark.
An alternative to mTESE is a percutaneous testicular sperm aspiration (TESA).
This procedure is simple to perform using a biopsy needle to aspirate testicular tissue under local anesthesia. It only costs around 500 $ to perform. The aspirated tissue is examined for the presence of spermatozoa and SRR for this procedure is usually reported around 40%. The lower SRR compared to mTESE is the main limitation of this method, but the procedure is well tolerated by patients due to its simplicity and short duration. It can easily be performed in the out-patient clinic.
However, there is no robust evidence on the optimal sperm retrieval protocol on men with NOA. This is in part due to the fact that no randomized trials have been performed to compare the two procedures.