Critical evaluation of the present experience on microsurgical sperm aspiration.

Microsurgical epididymal sperm aspiration (MESA) and IVF techniques are indicated in those cases of bilateral congenital absence of the vas deferens (BCAVD) and in cases of epididymal obstruction (EO) of other aetiologies were vasoepididymostomy is not possible or has failed. Microsurgical deferential sperm aspiration (MDSA) is indicated in those cases where spermatogenesis and epididymal permeability are conserved but spermatozoa, for different causes, cannot reach the ejaculate and other therapies have failed. We have performed this procedure in 70 patients by two different human reproduction teams. Both teams achieved very similar results regarding fertilization rate: 5.5 and 7.2% in cases of BCAVD, 6.5 and 8.8% in cases of EO and 33.3 and 26.7% in cases of non-epididymal pathology (NEP). However, the fertilization rate per patient presents differences between both teams: 27 and 44.4% in BCAVD, 31 and 11% in EO and 80 and 100% in NEP. In spite of a better fertilization rate per patient in team two, it was in the other where pregnancies were achieved (7% in BCAVD, 15% in EO and 20% in NEP). One pregnancy in EO group was achieved by intracytoplasmatic sperm injection. The pregnancy rates per transfer were 25% in BCAVD, 50% in EO and 25% in NEP.