Induction of varicocele in the dog: I. Partial ligation of the left renal vein does not induce a varicocele in the dog

Induction of varicocele was attempted by partial ligation of the left renal vein in 10 male dogs. The effects on sperm count, sperm motility, and sperm morphology, as well as on hemodynamics, were assessed. Furthermore, testicular, vascular, and kidney morphology was studied. Changes in the diameter and consistency of the left spermatic cord were found to be temporary. Total sperm count, sperm motility, and the total number of oval forms were not significantly altered. Hemodynamic studies revealed a renocaval pressure gradient, but retrograde flow in the distal part of the left testicular vein could not be observed by arteriography. A collateral network was found to compensate for the restricted left renal vein. Histologic examination revealed no damage to the seminiferous epithelium. Changes were not found in the kidney and left pampiniform plexus. Although some temporary changes induced by the partial ligation of the left renal vein are suggestive of varicocele, this hemodynamic study shows that the presented dog model does not mimic varicocele as encountered in man.