Venography of the left internal spermatic vein in patients with fertility problems.

A varicocele testis is frequently observed in males with fertility problems. The varicocele is caused by retrograde blood flow in the internal spermatic vein, as a rule on the left. This retrograde flow is also considered to be the main contributing factor causing infertility. Retrograde flow in the left internal spermatic vein may exist even if no varicocele is palpable during physical examination. Venography of the internal spermatic vein is helpful in detecting this retrograde flow and may also demonstrate a varicocele. Varicoceles occur predominantly on the left side (90%). The investigation is as a rule confined to visualization of the left internal spermatic vein. This examination can easily be performed on an outpatient basis. Various anatomical variants of the venous system may hamper selective catheterization of the left internal spermatic vein. For a better understanding of these anatomical variants, embryonal development of this venous system is discussed.