Abstract

Spermatozoa can be retrieved from either the epididymis or the testis, depending on the type of azoospermia, using different surgical methods such as PESA, MESA, TESA, TESE and micro-TESE. 

In cases of nonobstructive azoospermia (NOA), the efficiency of TESA for retrieving spermatozoa is lower than TESE, except in the favorable cases of men with previous successful TESA or testicular histopathology showing hypospermatogenesis. The use of microsurgery (Testicular Microdissection Sperm Extraction – MicroTESE) during TESE mproves the efficacy of sperm extraction with significantly less tissue removed, which ultimately facilitates sperm processing. Testicular histology results, if available, may be useful to predict the chances to retrieve sperm in men with NOA. Our data demonstrate that micro-TESE performs better than conventional TESE or TESA in cases of maturation arrest and Sertoli cell-only histological patterns, where tubules containing active focus of spermatogenesis can be positively identified using microsurgery. Testicular spermatozoa can be obtained even in the worst case scenario except in the cases of Y chromosome infertility with complete AZFa and/or AZFb microdeletions.

The main goal of micro-TESE sperm processing is the recovery of a clean sample containing motile sperm. Such specimens are more fragile, and often compromised in motility, as compared to the ones obtained from ejaculates. Laboratory techniques should be carried out with great caution not to jeopardize the sperm fertilizing potential. Testicular sperm obtained by micro-TESE can be intentionally cryopreserved for future use. Spare left-over specimens that would be discharged after ICSI can also be cryostored. 

The reproductive potential of infertile men with non-obstructive azoospermia undergoing ART is lower compared to other male infertility categories. Children conceived using sperm retrieved from men with NOA should be followed-up because it is still unclear if there is an increased risk of birth defects when ICSI is carried out with non-ejaculated sperm.

References

Verza S Jr, Esteves SC. Sperm defect severity rather than sperm source is associated with lower fertilization rates after intracytoplasmic sperm injection. Int Braz J Urol. 2008,34:49-56.

Esteves SC, Verza S, Prudencio C, Seol B. Sperm retrieval rates (SRR) in nonobstructive azoospermia (NOA) are related to testicular histopathology results but not to the etiology of azoospermia. Fertil Steril. 2010; 94(Suppl.):S132. 

Prudencio C, Seol B, Esteves SC. Reproductive potential of azoospermic men undergoing intracytoplasmic sperm injection is dependent on the type of azoospermia. Fertil Steril. 2010; 94 (Suppl):S232-3.

Microdissection testicular sperm extraction