Congenital Interruption of the Portal Vein and Caudal Vena Cava in Dogs: Six Case Reports and a Review of the Literature

Abstract

Veterinarians involved in diagnosis and surgery for portosystemic shunts should be aware of these potential malformations, and portal vein continuity should be evaluated in all dogs before attempting shunt attenuation.

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

“…they are found during diagnostic procedures not directed at this problem. The anomalies relate to a portosystemic shunt, connection of the caudal vena cava with the azygos vein, situs inversus and double caudal vena cava (HUNT et al, 1998;LABORDA et al, 1996;BARTHEZ et al, 1996;BERTOLINI et al, 2014). The embryonic foundation for the connection of the azygos vein with the caudal vena cava from a discontinuous prehepatic caudal vena cava has been described in detail (BUCHANAN, 1992;HUNT et al, 1998;BARTHEZ et al, 1996;NODEN and de LAHUNTA, 1985).…”

Imaging diagnosis: azygos continuation of a discontinuous caudal vena cava associated with portocaval shunting, incomplete situs inversus and polysplenia in a dog

“…This anomaly has been reported in dogs1–5 as a solitary finding, associated with a portosystemic shunt (portoazygos or posthepatic portocaval shunt),1 and with other visceral anomalies, such as situs inversus, situs ambiguous or polysplenia 1 3–5…”

Computed Tomography Angiography of Situs Inversus, Portosystemic Shunt and Multiple Vena Cava Anomalies in a Dog

“…This condition is the main characteristic of Kartagener’s syndrome with rhinosinusitis and bronchiectasis [7]. Situs inversus without dextrocardia has been reported with congenital vascular anomalies including portosystemic shunts (PSS) and azygos continuation of the caudal vena cava (CdVC) [10, 13, 15]. …”

“…The abdominal CdVC is divided into prerenal, renal, prehepatic, hepatic and posthepatic segments derived from the supracardinal, subcardinal and vitelline veins [10]. The retained middle segment of the supracardinal vein, normally regressed during normal development, plays a role as the connection between the embryonic CdVC and azygos vein, that is, the azygos continuation of the CdVC.…”

“…One other point claiming our attention in this anomaly is thrombosis, which can occur due to slowing blood flow of the shunt [9, 10]. We could define the functional shunt between the azyogos vein and renal CdVC and rule out thrombosis, shown as a filling defect, using CT angiography.…”