ICSI not only overcame the fertiliz

ICSI not only overcame the fertilization barrier presented by oligo-, astheno-, and eratozoospermia, it also created a new possibility for azoospermic men to achieve fertility. While Temple-Smith and colleagues reported the first pregnancy by microepididymal sperm aspiration (MESA) in a patient with secondary obstructive azoospermia in 1985, epididymal sperm motility was generally low and outcomes were poor compared with that of ejaculated sperm (Temple- Smith et al 1985). The advent of ICSI markedly improved fertilization rates with epididymal sperm, making the
combination of MESA–ICSI widely-used procedures for patients with congenital bilateral absence of vas deferens or secondary obstructive azoospermia. Subsequently, modified percutaneous sperm aspiration (PESA) performed with needle aspiration of the epididymis through a 1 cm scrotal incision, was developed as an alternative to MESA which required unilateral hemiscrototomy to allow
dissection, exploration, and aspiration of the epididymis with an operating microscope (Shrivastav et al 1994). Comparatively, PESA is cheaper, more acceptable to patients, has less postoperative morbidity than MESA, but retrieves fewer sperm.