STUDIES OF PERCUTANEOUS EPIDIDYMAL SPERM ASPIRATION (PESA) AND INTRACYTOPLASMIC SPERM INJECTION

Four distinct studies were carried out using two data sets of percutan eous epididymal sperm aspiration (PESA) and intracytoplasmic sperm inj ection (ICSI) procedures performed from March 1993 to January 1997. In study A, an analysis of 181 ICSI treatment cycles following PESA reve aled a successful epididymal sperm retrieval rate of 83%. It confirmed that PESA is an effective sperm retrieval method and the associated I CSI pregnancy rate (35% per embryo transfer) compared favourably with that of other sperm retrieval methods. In study B, the relevance of a prior diagnostic PESA procedure was ascertained by comparing the sperm retrieval rates in two groups of patients having their first ICSI tre atment cycle with spermatozoa retrieved through PESA. Group B1 (n = 50 ) had diagnostic PESA prior to the ICSI treatment cycle PESA procedure , unlike patients in group B2 (n = 64) who did not. The sperm retrieva l rate in the treatment cycle procedure was not different at 90 and 82 .8% for groups B1 and B2 respectively. However, the discontinuation of diagnostic PESA is fraught with problems including liability to medic o-legal sanctions. In study C, analysis of 177 treatment cycles involv ing PESA and ICSI revealed a successful sperm retrieval rate by PESA o f 82% in the first cycle, 93% in the second, 96% in the third and 100% in the fourth cycle. The same trend was evident when sperm retrieval was examined in relation to each of the epididymides. Retrieved sperma tozoa were found to be motile in 67-100% of cases and the frequency of samples containing motile spermatozoa did not decrease with increase in the number of PESA attempts. These results show that PESA does not jeopardize future epididymal sperm retrieval. In study D, the outcome of treatment with ICSI using ejaculated spermatozoa (305 cycles) (grou p D1) was compared with that of ICSI using spermatozoa obtained throug h PESA (54 cycles) (group D2). The median age of women in the two grou ps of couples was similar (34 years). In group D1, 70% of metaphase II oocytes were fertilized compared with 61% in group D2 (P < 0.01). The cleavage rate and the median numbers of transferred and cryopreserved embryos were similar in both groups. There was no significant differe nce between the clinical pregnancy rates (33 and 42% in groups D1 and D2 respectively). Our results show that the outcome of PESA-ICSI treat ment compares favourably with that of ICSI using ejaculated spermatozo a.