Computed tomographic and magnetic resonance imaging features of canine segmental caudal vena cava aplasia

Abstract

Segmental caudal vena cava aplasia is a vascular congenital anomaly in the dog that can be associated with thrombosis and portosystemic shunts. Computed tomographic angiography and magnetic resonance angiography are excellent tools to demonstrate the complex vascular anatomy and to guide treatment planning for portosystemic shunts and thrombolytic therapy.

Balloon dilation of an imperforate cor triatriatum dexter in a Golden Retriever with concurrent double-chambered right ventricle and subsequent evaluation by cardiac magnetic resonance imaging

“…As has been described previously 18 it is an excellent tool to demonstrate complex vascular anatomy, not restricted by specific imaging windows as is echocardiography, and it was successful in illustrating the dilated CS and CdVC entering the CdRA, as well as the DCRV lesion. It also confirmed the absence of a PLCVC and a left azygos, showed that the drainage of the right azygous vein was entering the terminal portion of the CrVC, adjacent to the CrRA, and proved to possess enough resolution to show the membranostomy orifice.…”

Magnetic Resonance Imaging Findings of Hepatic Encephalopathy in a Dog with a Portosystemic Shunt

“…Azygos continuation, which is also known as segmental caudal vena cava aplasia, is a condition in which the caudal part of the vena cava is absent and the azygos vein is connected with other systemic veins [6,7,16]. However, there are various forms of this condition; for example, the patient described in the present case had no caudal vena cava between the kidney and liver.…”

“…As a result, blood flow from the renal veins was anastomosed with the azygos vein directly into the nearby esophageal hiatus area. Although numerous cases of azygos continuation accompanied with PSS have been reported, it is not clear if it has any direct clinical significance [6,7,16].…”

Three-dimensional multislice helical computed tomography in the diagnostics of vena azygos connection to the caudal vena cava in a dog - a case report

“…In mammals the VCC (caudal vena cava) is formed from a series of processes which are involved in its development, regression and anastomosis, and it consists of three pairs of embryonal blood vessels: the supracardinal, subcardinal and navel veins (BUTLER, 1927;SCHWARZ et al, 2009). The anomalies which affect the venous system are rare in domestic carnivores.…”

“…The connection of the caudal vena cava with the azygos vein enables the flow of blood from the caudal vena cava towards the right atrium, through the azygos vein and the cranial vena cava (BARTHEZ et al, 1996;FISCHETTI and NOVAK, 2008). In aplasia of the caudal vena cava a connection may also appear between its cranial part and the azygos vein (SCHWARZ et al, 2009;HARDER, 2002). This anomaly was discovered by means of laparotomy.…”