Persistent left cranial vena cava with congenital heart defect in two dogs

Abstract

The purpose of this report is to introduce persistent left cranial vena cava (PLCVC) with persistent right aortic arch (PRAA) and patent ductus arteriosus (PDA). Case 1 was a Cocker Spaniel with PRAA and case 2 was a Maltese with PDA. PLCVC was enclosed at the sites of PRAA and PDA surgery; therefore, it was lifted dorsally during PDA and PRAA surgery. Surgery to repair congenital heart defects including PRAA and PDA is recommended for dogs that do not die of PLCVC at a young age.Keywords: congenital heart defect, patent ductus arteriosus, persistent left cranial vena cava, persistent right aortic arch, thoracotomy During fetal life, dogs normally have bilateral symmetrical cranial and caudal cardinal veins. As fetus developed, the right cranial cardinal veins direct fused and transformed into right cranial vena cava [3,5]. Left cranial cardinal veins usually become atrophied and left caudal cardinal veins develop into coronary sinus. But in persistent left cranial vena cava (PLCVC) there is abnormal development of the sinus venosus and left cranial cardinal veins are not atrophied and remain the left common cardinal vein at the coronary sinus [3]. There are two types of PLCVC reported in the dog, a complete one in which the non-atrophied left cranial cardinal vein retains its embryological connection with the coronary sinus [11] and an incomplete one where the distal portion of the left cardinal vein atrophies as normal, but the proximal portion of the left cranial vena cava receives a vein which drains the left costocervical vertebral trunk [5]. PLCVC is an uncommon vascular anomaly but coexists with other congenital heart defects [6,12]. PLCVC itself did not show significant clinical signs in most cases but mostly detected when cardiovascular imaging performed for other reasons [1,6]. A study in dogs reported that 12% of vascular rings was consisted of an association of persistent right aortic arch (PRAA) and PLCVC. In these cases clinical signs of esophageal disease due to PRAA are usually appear [2]. If PLCVC drains into right atrium, there is no clinical significance [17]. In human medicine PLCVC called persistent left superior vena cava (PLSVC). In numerous instances PLSVC was found accidentally during cardiovascular imaging or surgery [9]. Although it is present up to 0.5% in general population without congenital abnormalities [10,15]. Almost 40% of the patient show different kinds of congenital anomalies like as coronary sinus ostial atresia, atrial septal defect, coarctation of aorta, and bicuspid aortic valve [13,15,18]. It can cause arrhythmias and cardiogenic shock due to secondary causes such as physiologic stresses placed on the conductive tissue due to abnormal anatomy that can lead to the enlargement of the right atrium [14]. Many types of PLSVC are present in human medicine, hence, many types of treatments exist like PLSVC anastomosed to right atrial appendage, cardiac catheterization and pacemaker implant [8,9,16]. In veterinary medicine, as diagnostic tool development, PLCVC is diag...

Anomalous drainage of the caudal vena cava into the left atrium and duplication of the posthepatic caudal vena cava in a cat diagnosed with CT

“…In veterinary medicine, caudal vena cava anomalies such as duplication of the prehepatic caudal vena cava,18 19 aplasia20–22 and transposition21 of the caudal vena cava have been reported. There are also several reports of persistent left cranial vena cava in dogs 23–26. To the authors’ knowledge, this is the first report of anomalous drainage of the caudal vena cava into the left atrium and duplication of the posthepatic caudal vena cava in veterinary medicine.…”

“…There are also several reports of persistent left cranial vena cava in dogs. [23][24][25][26] To the authors' knowledge, this is the first report of anomalous drainage of the caudal vena cava into the left atrium and duplication of the posthepatic caudal vena cava in veterinary medicine.…”

Complete type persistent left cranial vena cava with patent ductus arteriosus in a Bichon Frise dog

“…During the surgery, it was difficult to find the landmarks of PDA. PLCVC was located immediately above the PDA and vagus nerve [20]. PLCVC made it harder to find the landmarks, vagus nerve and patent duct.…”

Surgical Ligation of Patent Ductus Arteriosus Using the Descending Aortic Approach in Two Dogs

“…Occasionally, a persistent left cranial vena cava (PLCVC) will exist in addition to the PDA (7,14). It is recommended that the PLCVC should not be ligated or dissected (8).…”

“…It is recommended that the PLCVC should not be ligated or dissected (8). As the PLCVC anatomically overlies the ductus arteriosus, it should be carefully separated and retracted dorsally along with the vagus nerve in order to proceed with the dissection of the ductus arteriosus (7,8).…”