An uncommon type of infertility (1-2%) occurs where the male partner has no sperm in the semen (azoospermia). The cause may be either obstructive or non-obstructive.
In about half the cases sperm production by the testes is normal but there is a blockage, which prevents sperm entering the semen (obstructive azoospermia).
This may be due to -
- failure of the sperm passages to develop (congenital absence of the vas)
- blockage of the sperm transport tubules
- previous vasectomy operation (male sterilisation).
Although many vasectomies can be corrected by surgery this may be unsuccessful.
At present we have no certain methods of re-constructive surgery to offer men with congenital absence of the vas.
In non-obstructive azoospermia there is failure of adequate sperm production by the testes.
This is either a congenital problem, the result of previous disease, or of surgery, chemotherapy, or x-ray treatment. Even in these patients, sampling (biopsy) of the tissue of the testis reveals that many men (about 30-40%) have areas within the testes where there are normal sperm, which do not pass into the semen even though there is no blockage.
ICSI – Intra Cytoplasmic Sperm Injection
ICSI is an advanced type of in-vitro fertilisation (IVF) treatment where fertilisation is achieved by microinjecting a single sperm into each suitable egg. With the benefit of ICSI we are able to obtain fertilisation from very few sperm obtained from men who are sterile due to the above problems.
PESA and TeSE
PESA and TeSE are the minimally invasive techniques of obtaining sperm from either the epididymis or testis. They are usually performed under a general anaesthetic.
PESA - Percutaneous Epididymal Sperm Aspiration
A fine needle is inserted into the epididymis, at the upper area of the testis and sperms are obtained by gentle suction.
TeSE - Testicular Sperm Extraction
A fine needle is inserted into the testis and samples of tissue are obtained by gentle suction in order to retrieve enough sperms. If too few sperms are obtained a biopsy (tissue sample) is taken through a small incision and 2-3 stitches are placed in the skin which self-dissolve in about 10 days.