Course of the arteria vertebralis in its segment V1 from the origin to its entry into the foramen processus transversi.

The segment V1 of the arteria vertebralis (pathway from its origin from the a. subclavia to the entry into the respective foramen processus transversi) has a special significance in vascular surgery. Contrary to indications in the literature, we found 47.15% of the specimens to have a contorted course in this segment. The tortuosities carried by the respective vessels were found to be horizontal in 42.5%, in a sagittal direction in 30% and in the frontal plane in 27% of the cases. However, no significant difference was found between vessels carrying a tortuosity and those without, regarding the average lengths of the arteries concerned in the segment V1.