Varicocele and left renal vein compression.

Several current theories concerning the possible etiology of varicocele are critically reviewed. The possibility of arterial compression of the left renal vein, probably by the superior mesenteric artery is elaborated upon. Since direct experimentation is impossible because of the exclusively human character of this disease, a "triple indirect approach" is adopted. Three differently directed studies are conducted: intraoperative antegrade spermatic phlebography visualizing the left renal vein, anatomic dissection of the left renal vascular pedicle, and intraoperative marking of the superior mesenteric artery and the left renal vein for in vivo studies of their relationships. Because the outcomes of these three pathways converge and focus on the superior mesenteric artery compression of the left renal vein, it is concluded that this is a probable contributing mechanism in the etiology of varicocele.