Enzymatic digestion of testicular tissue may rescue the intracytoplasmic sperm injection cycle in some patients with non-obstructive azoospermia

Recovery of testicular spermatozoa from azoospermic patients with testicula r failure, followed by intracytoplasmic sperm injection (ICSI) is a recent advance in the treatment of male infertility, In most cases, free spermatoz oa are recovered from testicular tissue after mechanical mincing of multipl e biopsies. Testicular sperm retrieval, however, remains unsuccessful in 30 -50% of male patients suffering from Sertoli cell-only syndrome and maturat ion arrest. In this study, a strategy was developed in order to maximize th e chance of sperm retrieval in difficult cases of testicular failure. The u ltimate step was the use of enzymatic procedures (collagenase type IV) to d issociate the testicular tissue completely. Testicular tissue of 41 patient s for whom no spermatozoa were found after mechanical mincing of the testic ular tissue was investigated, In 14 out of the 41 cases (34%), enough sperm atozoa for ICSI were found after fine mincing of multiple biopsies and seve ral hours' search in the cell suspension treated with the erythrocyte-lysin g buffer (ELB), In 27 out of the 41 patients, no spermatozoa were found eve n after the use of ELB, In seven out of these 27 failures (26%), spermatozo a for ICSI were retrieved after enzymatic dissociation of the residual minc ed tissue pieces, thus making ICSI possible despite failure to find spermat ozoa with conventional mincing. From this study, we may conclude that enzym atic digestion of testicular tissue is easy to perform, is not time-consumi ng and constitutes a successful method in reducing the sperm recovery failu res in patients with non-obstructive azoospermia.