No differences in outcome after intracytoplasmic sperm injection with fresh or with frozen-thawed epididymal spermatozoa.

This retrospective consecutive case series aimed at comparing the results of intracytoplasmic sperm injection (ICSI) with fresh and with frozen-thawed epididymal spermatozoa obtained after microsurgical epididymal sperm aspiration (MESA) in 162 couples. These couples were suffering from infertility because of congenital bilateral absence of the vas deferens (n = 109), failed microsurgical reversal for vasectomy or postinfectious epididymal obstruction (n = 44), irreparable epididymal obstruction (n = 4), ejaculatory duct obstruction (n = 2) or anejaculation (n = 3). Overall, 176 MESA procedures were performed in the husbands, followed by 275ICSI procedures with either fresh (n = 157) or frozen-thawed (n = 118) epididymal spermatozoa. No significant differences were observed in the parameters of spermatozoa used either freshly or frozen-thawed. In the fresh epididymal sperm group 59.4% of all the injected oocytes fertilized normally as compared to 56.2% of all injected oocytes in the frozen-thawed epididymal sperm group, and embryonic development was comparable between the two groups. A total of 245 transfers were performed: 145 after the use of fresh epididymal spermatozoa and 100 after the use of frozen-thawed spermatozoa. The overall pregnancy rate per ICSI cycle was significantly lower when frozen-thawed epididymal spermatozoa were used (26.3 versus 39.5%). However, no significant differences were found either in clinical and ongoing pregnancy rates or in implantation rates. There were no differences in pregnancy outcome. In patients suspected of having obstructive azoospermia with no work-up or an incomplete one, MESA is the preferred method for sperm recovery because a full scrotal exploration can be performed and, whenever indicated, a vasoepididymostomy may be performed concomitantly. Recovery of epididymal spermatozoa for cryopreservation during a diagnostic procedure is certainly a valid option in these patients since ICSI may be performed later or even in another centre using the frozen-thawed epididymal spermatozoa without jeopardizing the ICSI success rate.