Techniques for surgical retrieval of sperm prior to intra-cytoplasmic sperm injection (ICSI) for azoospermia

Azoospermia, the absence of sperm in ejaculated semen, is the most severe form of male-factor infertility and is present in approximately 5% of all investigated infertile couples. The advent of intra-cytoplasmic sperm injection (ICSI) has transformed treatment of this type of severe male-factor infertility. Sperm can be retrieved for ICSI from either the epididymis or the testis, depending on the type of azoospermia.

To evaluate the efficacy of the various surgical retrieval techniques for men with obstructive or non-obstructive azoospermia prior to ICSI.

We searched the Cochrane Menstrual Disorders and Subfertility Group Trials Register (November 2007), Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, Issue 4), MEDLINE (1966 to November 2007), EMBASE (1980 to November 2007), Biological Abstracts (1980 to November 2007), and reference lists of identified articles.

Randomised controlled trials (RCTs) comparing the effectiveness of different sperm-retrieval techniques in men with azoospermia prior to ICSI. Due to the lack of RCTs, non-randomised trials that used the participants as their own control were also considered in the review but their results were not included in the meta-analysis.

Two review authors independently assessed trial quality and extracted data. Study authors were contacted for additional information.

The search was revised and re-run in November 2007. No new trials were located therefore the results of the updated review remain unchanged from those published in 2006. Two trials involving 98 men were included. The first small RCT had 59 participants and compared two epididymal techniques. The trial gave limited evidence that microsurgical epididymal sperm aspiration (MESA) achieved a significantly lower pregnancy rate (one pregnancy in 29 procedures compared with seven pregnancies in 30 procedures; OR 0.19, 95% CI 0.04 to 0.83) and fertilisation rate (OR 0.16, 95% CI 0.05 to 0.48) than the micropuncture with perivascular nerve stimulation technique. The other RCT comparing two testicular aspiration techniques (TSA) in 39 participants gave no statistically significant evidence for the superiority of the ultrasound-guided technique compared to the aspiration technique without ultrasound. TSA with ultrasound resulted in pregnancy in three out of 16 participants compared with four out of 23 participants (OR 1.10, 95% CI 0.21 to 5.74).

There is insufficient evidence to recommend any specific sperm retrieval technique for azoospermic men undergoing ICSI. In the absence of evidence to support more invasive or more technically difficult methods, the review authors recommend the least invasive and simplest technique available. Further randomised trials are warranted, preferably multi-centred trials. The classification of azoospermia as obstructive and non-obstructive appears to be relevant to a successful clinical outcome and a distinction according to the cause of azoospermia is important for future clinical trials.