Table 8. Presence of mature sperm in testicular biopsies of men with non-obstructive azoospermia

Most authors recommend taking several testicular samples given the possible regional differences [38,39]. Other authors support the hypothesis that a single sample is demonstrative of the total histological pattern [20,40]. Many authors find a good correlation between diagnostic biopsy histology and the likelihood of finding mature sperm cells during testicular sperm retrieval and ICSI [14,31,41].

Biopsy techniques

Testicular biopsy is a simple outpatient procedure under local anaesthesia.

There are different techniques for performing a testicular biopsy:

1) Open biopsy. An incision is made on either side of the midline raphe. The tunica albuginea is visualized.
With a scalpel blade, an incision is made into the tunica albuginea. Gentle pressure on the testis will
facilitate tissue removal by using a pair of small straight blade scissors. The specimen is transferred into
Bouin's solution. Formaldehyde solution should never be used.

At this stage of surgery, the epididymis is mobilized to assess its morphological characteristics and to

exclude mechanical causes of azoospermia.

To date it is unclear whether a microsurgical approach [37] leads to better results.

The standard testicular biopsy can also be combined with testicular touch preparation cytology [42].

2) Percutaneous testicular biopsy. Some authors prefer percutaneous biopsies for diagnostic purposes
arguing that this procedure is simpler than open testicular biopsy [43-46]. Apart from being associated
with insufficient tissue collection for histological examination [47], this technique may result in specimen
artefacting, refractory haematomas and unintentional damage to the epididymis.

3) Testicular fine needle aspiration. Some authors advocate testicular spermatozoa fine needle aspiration
as a diagnostic method [48-50], while others [51] do not find this technique as effective as open
testicular biopsy for histopathological diagnosis.

Any type of testicular biopsy should provide sufficient material to cryopreserve sperm for future ICSI cycles [52]. If these spermatozoa have some degree of motility, they have a good potency for fertilization and successful implantation.

3.5 Treatment

TESE and ICSI were introduced in 1993 for treatment of obstructive azoospermia [53-55]. It was soon discovered that this technique could also be used for azoospermic men who appeared to have absent spermatogenesis [56]. If spermatozoa are detected in the testicular biopsy, ICSI with either cryopreserved or fresh spermatozoa can be proposed to the couple. A karyotype (if not performed previously) and Yq deletions screening are indicated to analyse any therapeutic consequences for the newborn child. If genetic anomalies are detected, the couple has to be properly informed and counselled (see above Genetic disorders in infertility). Table 9 shows the sperm retrieval/ICSI results of the most important series conducted to date. Of 616 TESE procedures, 373 (60.5%) yielded sperm for ICSI. The mean fertilization rate was 52.5% (38.6-69%) and the mean pregnancy rate was 29.2% (11.3-31 %).

Table 9. Non-obstructive azoospermia: results obtained using TESE and ICSI. (Adapted from review of published series)

Predictive parameters for successful TESE:

In the majority of series, aetiological factors, patient's age, testicular volume, serum FSH and histopathological patterns showed that no potential predictive parameter precluded successful testicular sperm retrieval.

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 is always 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].

Date: 2016-06-12; view: 200