Persistência da veia cava cranial esquerda em cão / Persistent Left Cranial Vena Cava in a Dog

ABSTRACT

Background: Persistent left cranial vena cava with absent right cranial vena cava is a rare anomaly. Congenitally persistent left cranial vena cava is the most common variant of the systemic venous return to the heart, embryologically resulting from failure of the anterior cardinal vein in becoming obliterated. Persistent left cranial vena cava is the most common form of anomalous venous drainage involving the cranial vena cava, and represents persistence of the left horn of the embryonic sinus venosus, which normally involutes during normal development, becoming the coronary sinus. Usually, persistent left cranial vena cava enters the right atrium through the orifice of an enlarged coronary sinus. Persistent left cranial vena cava is an uncommon congenital cardiovascular anomaly in dogs, generally coexisting with other more serious cardiac defects. The condition is rare as an isolated single defect. The left cranial vena cava is observed only among domestic mammals, but it is a relatively rare anomaly that can be found in other species, including man, without causing clinical problems. The objective of this study was to report the occurence of a rare vascular formation of the cranial vena cava, which caused the persistence of the left cranial vena cava instead of the right one. Case At the anatomy laboratory of the Faculty of Veterinary of the UFGRS, a male dog was identified with a persistent left cranial vena cava and absent right cranial vena cava.[...](AU)