[Spermatic recovery techniques for intracytoplasmic spermatozoid injection (ICSI) in male infertility]

The introduction of intracytoplasmic spermatozoid injection (ICSI) not only has improved significantly the prospects of fertility after assisted reproduction by using spermatozoa recovered from the seminal tract, but also has allowed extension of the spectrum of recovery techniques. For obstructive azoospermia, it is currently possible to use not only spermatozoa obtained by microsurgical techniques from the epididymis (MESA), but also spermatozoa obtained from the testicle by means of testicular biopsy (TESE), or spermatozoa percutaneously aspirated from the testicle/epididymis by minimally invasive techniques (TESA, PESA). Minimal requirements in terms of spermatic quality for ICSI have also allowed to successfully criopreserve epididymal and testicular spermatozoa. ICSI results are not influenced by the origin of spermatozoa (epididymis or testicle), neither by the technique of spermatic recovery. Fresh or criopreserved spermatozoa microinjections are not different either. On the other side, 40-60% of patients with secretory azoospermia show small foci with preserved spermatogenesis in their testicles. For ICSI, these scarce spermatozoids may also be extracted from the testicle by multiple open biopsies, percutaneous aspiration, or microsurgical biopsies (micro-TESE). Nevertheless, in secretory azoospermia the yield of percutaneous techniques is lower than open or microsurgical procedures. It is also possible to criopreserve testicular spermatozoa in secretory azoospermia without the process significantly influencing ICSI results. Finally, spermatozoid testicular recovery by biopsy or percutaneous aspiration followed by ICSI has also been employed as a resource in patients with necrozoospermia and anejaculation.