3.6 Tese techniques

Open biopsy and fine needle aspiration are the two main techniques to retrieve sperm from the testicle.

Although fine needle aspiration enables more areas of the testis to be reached, open testicular biopsy allows more tissue and sperm to be retrieved [57]. TESE is performed as described in the diagnostic section. TESE isalways performed in both testes. Two or three small incisions are made through the tunica albuginea in different regions at the tree rim of each testis and small pieces of extruding testicular tissue are removed. The fragments of testicular tissue are immediately placed in a Petri dish containing 2 mL of culture medium and transferred to the IVF laboratory.

For needle aspiration, a 21-gauge butterfly needle attached to a 20 mL plastic syringe serves as an aspiration device. The butterfly needle is passed directly into the testicular tissue. While holding the testicle between the index finger and the thumb, different entries are made in each testicle, sampling various locations. Before retrieving the needle from the testis, small artery forceps are used to clamp the butterfly needle's microtubing. Following aspiration, the needle is flushed with culture medium into one well of a four-well plate. For each puncture, a new butterfly needle is used [58].

Physiological consequences of testicular sperm retrieval:

In cases of non-obstructive azoospermia, multiple TESE or testicular punctions have been associated with focal inflammation and haematoma, as well as impaired testicular blood flow [59]. In small testes, an intermittent decrease of serum testosterone levels is under debate. The long-term consequences of these findings are unclear.

3.7 Icsi with cryopreserved testicular spermatozoa

ICSI performed with cryopreserved testicular spermatozoa has been successful [8,30,33,52,60-64].

In the majority of series, results obtained with fresh and cryopreserved sperm were not significantly different.It also appears that sperm survival after cryopreservation is not influenced by infertility aetiology, serum FSH concentration, or patient's age.

3.8 Tese and icsi in Klinefelter's syndrome

Palermo [36] obtained spermatozoa in four out of seven TESE procedures in six men with non-mosaic Klinefelter's syndrome. Fertilization was achieved in 68% of oocytes. Five healthy newborns, all karyotypically normal, were delivered. Other pregnancies have been reported [65-68].

3.9 Testicular spermatid injection in combination with icsi

Previous studies have shown that fertilization and delivery of healthy offspring can occur after transferring round spermatid nuclei into rabbit or mouse oocytes via microsurgical methods [69-71]. Edwards [72] first suggested that ooplasmic injections of spermatids might serve as a novel mode of therapy for non-obstructive azoospermia. Acceptable fertilization rates and pregnancies after ooplasmic injection of round spermatid nuclei have been reported [73-77]. Complete absence of spermatozoa from the ejaculate or testicular biopsy has an adverse effect on the clinical outcome [77,78].

In cases with very severe spermatogenetic defect, pregnancies can be achieved with elongated spermatidcells. However, the efficacy of round spermatids in achieving fertilization and pregnancy is disappointing.