Comparison of coronary arteries morphometry and distribution in bovines with humans and other animal species.

Background: The left coronary artery (LCA) in the bovines is more developed than the right. Aim: The objective of the study is to describe the bovine coronary system from a morphological point of view, including the morphometry and its distribution. Methods: Arciform suture with 2.0 silk was applied around the sinus orifice and coronary ostium and a number 14 catheter was installed, to perfuse semi-synthetic polyester resin, consisting of a mixture of 85% GP40L palatal with 15% styrene with red color mineral. Results: The average weight of 28 bovine hearts used in our study was 1.534.1 kg. The right coronary artery had a proximal caliber of 5 +/- 0.9 mm. The LCA caliber and length were 9.4 +/- 1.2 and 18.3 +/- 4.8 mm, respectively. This artery was divided into two branches in 85.7% of the cases and trifurcated in 14.3%. The paraconal interventricular branch (PIB) ended more frequently in the apex (46.4%), and its proximal caliber was 6.4 +/- 1.4 mm. The left circumflex branch ended in 82.1% in the subsinusal interventricular sulcus, and its proximal caliber was 5.9 +/- 1.2 mm. The proximal calibers of the PIB and the left circumflex branch did not present statistically significant differences (p = 0.137). The sinoatrial branch presented a dual origin (right and LCA) in 46.4% of the cases and a single origin from the LCA in 53.6% of the samples. In the evaluated hearts, left coronary dominance was observed in most cases (96.4%). Their presence of anastomosis between the branches of the coronary arteries was observed in 57.1% of cases. Conclusion: The presence of a myocardial bridge was found in six hearts (21.4%). In bovines, a high percentage of anastomosis was found, a protective factor in obstruction of the coronary arterial branches.