The Anatomical Correlation between the Internal Venous Vertebral System and the Cranial Venae Cavae in Rabbit

The aim of this study was to describe the possible variations in the connection between the internal venous vertebral system and the cranial vena cava in rabbit using corrosion technique. The study was carried out on 40 adult New Zealand white rabbits. The venous system was injected by using Batson's corrosion casting kit number 17. We found the connection between the internal venous vertebral system and the cranial vena cava by means of the vertebral veins and the right azygos vein. The vertebral vein was present as independent tributary in 36 cases (90%). In the rest of the cases, it was found as being double, being triple, or forming a common trunk with other veins. The azygos vein was present as independent tributary of the cranial vena cava in 39 cases (97.5%). We found also a common trunk formed by the junction of the deep cervical vein, the right vertebral vein, and the azygos vein in one case (2.5%). The azygos vein received 6, 7, 8, or 9 pairs of dorsal intercostal veins. Documenting the anatomical variations in the rabbit will aid in the planning of future experimental studies and determining the clinical relevance on such studies. 1. Introduction The knowledge of anatomical variations is important for radiological and surgical procedures in humans and animals due to its practical and theoretical significance for experimental research and surgical practice in experimental and domestic animals [1]. The variations of internal venous vertebral system and its main veins were best described in humans [2]. The internal venous vertebral system as venous plexus lying within the vertebral canal in the epidural space was described as a possible way of metastatic tumors means of injecting experiments in several animals [3]. Rabbits have been used as experimental model in many diseases [4]. The aim of this study was to describe the possible variations in connection between the internal venous vertebral system and the cranial vena cava in rabbit using corrosion technique. 2. Material and Methods The study was carried out on 40 adult rabbits (age 140 days). We used New Zealand white rabbits (breed HY+) of both sexes (female ; male ) with an average weight of 2.5–3？kg in an accredited experimental laboratory at the University of Veterinary Medicine and Pharmacy in Kosice. The animals were kept in cages under standard conditions (temperature 15–20°C, relative humidity 45%, and 12？h light period), and fed with granular feed mixture (O-10 NORM TYP). Drinking water was available for all animals ad libitum. The animals were injected intravenously with heparin