I-4: Sperm Retrieval: 2013 Updates

Men with congenital absence or bilateral partial aplasia of vas deferens, or those with failed or surgically unreconstructable obstructions or azospermic men with testicular failure or genetic cause can now be treated by using sperm retrieval techniques in conjunction with in vitro fertilization/intra cytoplasmic sperm injection (ICSI/ IVF). These techniques are: Microsurgical epididymal sperm aspiration (MESA) procedure allows lower complication rate ,require anesthesia and microsurgical skills, has better motility than TESE and large number of sperm can be harvested for cryopreservation. It is indicated for Nonobstructive Azospermia. Percutaneous puncture of the epididymis with a fine needle has been successfully employed to obtain sperm and achieve pregnancies. Percutaneous epididymal sperm aspiration (PESA) results in lower retrieval rates than microsurgical testicular sperm extraction (TESE) and does not allow histological examination to detect carcinoma in situ (CIS) and testicular malignancies. PESA may also result in more tubular and vascular damage than TESE . Testicular biopsy can be part of ICSI treatment in patients with clinical evidence of NOA. TESE is the technique of choice and shows excellent repeatability. Royan institute randomized control study, which was done with a larger sample size than similar published studies indicate that multifocal TESA is more effective and simply done than TESE for sperm retrieval and could be the preferred approach. Spermatogenesis may be focal, which means that in about 50% of men with NOA, spermatozoa can be found and used for ICSI. Most authors therefore recommend taking several testicular samples .There is a good correlation between the histology found upon diagnostic biopsy and the likelihood of finding mature sperm cells during testicular sperm retrieval and ICSI. However no threshold value has been found for FSH, inhibin B, or testicular volume and successful sperm harvesting. When there are complete AZFa and AZFb microdeletions, the likelihood of sperm retrieval is almost zero. Although Choi (2013) showed in NOA and OATS patients, no significant difference in the sperm retrieval rate was shown between patients with Y chromosome microdeletion and those with no microdeletion. Patients with short Y chromosome microdeletion such as AZFc microdeletion have better prognoses for sperm retrieval and an increased chance of conception than do patients with larger microdeletions such as AZFb-c microdeletion. The use of an operating microscope for standard open diagnostic testes biopsy allows identification of an area in the tunica albu‌ginea free of blood vessels, minimizing the risk of injury to testicular blood supply and allowing a relatively blood-free biopsy specimen .Employing the microscope for testis biopsy, discovered that in men with nonobstructive azoospermia, some of the tubules were larger than others. The larger tubules are more likely to yield sperm. Microsurgical TESE may increase retrieval rates versus conventional TESE, even though comparative studies are not yet available .Positive retrievals are reported even in conditions such as Sertoli cell only syndrome type II . The results of ICSI are worse when using sperm retrieved from men with NOA compared to sperm from ejaculated semen and from men with obstructive azoospermia (OA) .Birth rates are lower in NOA versus OA (19 vs. 28%). In OA, there were no significant differences in ICSI results between testicular and epididymal sperm. Also, no significant differences have been reported in ICSI results between the use of fresh and frozen-thawed sperm. Pregnancies and live births are eventually obtained in 30-50% of couples with NOA, when spermatozoa have been found in the testicular biopsy. Men who are candidates for sperm retrieval must receive appropriate genetic counseling. Testicular biopsy is the best procedure to define the histological diagnosis and possibility of finding sperm. Spermatozoa should be cryopreserved for use in ICSI. For patients with NOA who have spermatozoa in their testicular biopsy; ICSI with fresh or cryopreserved spermatozoa is the only therapeutic option. Men with NOA can be offered TESE with cryopreservation of the spermatozoa to be used for ICSI. To increase the chances of positive sperm retrieval in men with NOA, TESE (single, multiple or microsurgical) should be used rather than PESA. Among sperm acquisition methods, micro-TESE has higher success rates at obtaining sperm compared with testicular sperm extraction and testicular sperm aspiration.