Variability of the v. cava caudalis and its tributaries in some laboratory animals. I. The guinea pig (Cavia aperea f. porcellus).

The authors studied variability of the v. caudalis and its tributaries in 30 guinea pigs (Cavia aperea f. porcellus--15 males and 15 females) after injecting the relevant venous system with blue-dyed latex. Since the largest lobe of the guinea pig's liver (the lobus sinister) is situated on the left, the right kidney lies further cranially than the left one. In males, as a rule, the right v. renalis opens into the v. cava caudalis further cranially than the left one. The number of vv. renales showed no sex-related differences, although in 17 regions (i.e. in 29%) there was more than one. The increase most often concerned the v. renalis dextra (the ratio in relation to the left vein was 15:2). The tributaries of the vv. renales are the v. spermatica or v. uterina cranialis a v. lumbalis and a v. or vv. suprarenales. There are usually two tributaries, (the commonest of which is the v. spermatica or v. uterina cranialis) on both the right and the left side, though somewhat more frequently on the left (23:19). Blood is drained from the surface or capsule of the kidney relatively often (in 75% of the cases) by the capsularis, which is the most frequent tributary of the v. spermatica or v. uterina cranialis of the corresponding side. Vv. suprarenales (1-4) are a constant finding on both sides. In males they open more often into the v. cava caudalis and in both sexes they also open into the v. renalis and v. lumbalis. The v. spermatica dextra opened into the v. renalis dextra in 10 cases and the v. spermatica sinistra into the v. renalis sinistra in 12 cases. The v. uterina cranialis dextra was a tributary of the v. renalis dextra in eight cases and the v. uterina cranialis sinistra joined the v. renalis sinistra in 13 cases. Drainage into the v. renalis can thus be regarded as the norm in both sexes and on both sides. The v. uterina caudalis leads from the corpus and cervix uteri and joins the v. uterina cranialis. It has a regular incidence and caudally it is most often a tributary of the v. iliaca communis. The v. ovarica is a constant tributary of the v. uterina cranialis; it is usually joined by several vv. lumbales or v. v. capsulares.(ABSTRACT TRUNCATED AT 400 WORDS)