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Disorders of sperm transport following sterilisation

The treatment of infertility depends on the established cause.
Disorders of sperm transport resulting from sterilisation can be treated most successfully.

In this case, the previously severed vasa deferentia can be reconnected under the high-resolution surgical microscope. The success rate of restoring the patency of the vas deferens is up to 70%; the pregnancy rate is somewhat lower. The image below shows the surgeon’s view through the microscope during the surgery (vasovasostomy).

The image on the left shows the sutures used to reconnect the ends of the vas deferens. These sutures are thinner than human hair; the diameter of the duct is less than 1 mm. The image on the right shows the reconnected vas deferens with the knotted sutures.

Treatment options are also available in some of those cases where the vas deferens is obstructed for other reasons. In these cases, however, the success rates are lower than after sterilisation.

Disorders of sperm production

If the infertility is caused by a disorder of sperm production, in-vitro fertilisation is necessary in most cases. In this process, the ova are fertilised with spermatozoa in a test tube. Following successful fertilisation, the fertilised ovum is introduced into the uterus.
The decisive factor is whether spermatozoa are found in the ejaculate and can thus be obtained naturally or whether spermatozoa are not present at all (azoospermia). In this case, surgical intervention under a short anaesthesia is required to remove testicular tissue hopefully containing sperm cells. This can either be used immediately for in-vitro fertilisation or can be deep-frozen in liquid nitrogen at -196 °C (cryopreservation).


The cryopreservation of testicular tissue is not only required for in-vitro fertilisation. Young men are often affected by other conditions the treatment of which poses a risk to fertility. For example, chemotherapy or radiotherapy for cancer treatment may temporarily or even permanently affect the production of spermatozoa. In such cases, we can ensure fertility by deep-freezing spermatozoa before the treatment is started. This way, both ejaculate and testicular tissue can be stored (cryopreserved) for later in-vitro fertilisation. Unfortunately, this option is not included in the scope of services of health insurance funds, which is why patients need to pay themselves for the procedure and storage. The images below show some process steps of cryopreservation.

The image on the left shows the injection of spermatozoa, dissolved in a special cryopreservation medium, into the storage tubes (referred to as straws).
The image in the middle shows the filling of liquid, ice-cold (-196 °C) nitrogen into the cryopreservation container.
The image on the right shows the transport box shipped to an external service provider who takes care of the long-term storage.


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