Assisted semen collection using two phosphodiesterase type 5 inhibitors （Tadalafil and Sildenafil） in infertile men with mild erectile dysfunction

In the past 50 years, dramatic advances have been Lachieved in male infertility treatment. Intracytoplasmicsperm injection （ICSI） provides an effective manipulation for bypassing some severe etiologies of male fertility. However, some men may encounter difficulty in semen collection by masturbation on demand at the time of undergoing assisted reproductive technology （ART）. If a patient is unable to provide semen by masturbation, he has to undergo testicular sperm extraction （TESE） to collect spermatozoa for ICSI, which is expensive and invasive. Some men fail to obtain semen by masturbation because of temporary erectile dysfunction （ED）.