Abernethy Malformation Type1, Type 1a, Type 1b & Type 2

An Abernethy malformation is an extremely uncommon type of vascular defect that affects the portal venous system. It is also known as congenital portosystemic shunts. In 1793, Abernethy published the first description of this condition, and since then, only 80 cases have been reported. Early prenatal ultrasounds (as early as 14 weeks) and examinations for other prenatal disorders can both identify Abernethy abnormalities. Depending on the position, size, and shape of the shunt, there are various treatment options for Abernethy malformation. 

Abernethy Malformation Type1

It is a rare form of congenital vascular abnormality known as Abernethy Malformation Type 1, which is also known as congenital extrahepatic portosystemic shunt (CEPS). This condition occurs when the portal vein, which is responsible for transporting blood from the digestive organs to the liver, does not develop correctly. Instead, the blood bypasses the liver and travels directly to the inferior vena cava, a vital vein that returns blood to the heart.

Many symptoms, such as liver malfunction, developmental problems, and neurological abnormalities, might be brought on by this illness. Some persons with Abernethy Malformation Type 1 may experience very mild symptoms, while others may experience severe symptoms.

The diagnosis of Abernethy Malformation Type 1 often involves imaging studies, such as ultrasound, CT scan, or MRI, to examine the blood flow in the liver and the shunt. The treatment may require surgery to seal the shunt and reestablish normal blood supply to the liver, or pharmacological therapy to control symptoms.

Type 1 Abernethy Malformation is extremely uncommon, and its root cause is poorly known. It may manifest either alone or as a hereditary syndrome. The severity of the abnormality and the specific instance dictate the course of treatment and prognosis.

Abernethy Malformation Type 1a & Type 1b

Abernethy Malformation Type 1 can be broken down into two subtypes based on whether or not a fetal blood vessel called the patent ductus venosus (PDV), which usually closes after birth, is present. 

Abernethy Malformation Type 1a: This subtype is distinguished by the lack of the portal vein and the presence of a patent ductus venosus (PDV). The PDV serves as a bypass for the liver, allowing blood from the intestines and other abdominal organs to enter the inferior vena cava, a major vein that transports blood from the lower body to the heart, without passing via the liver.

Abernethy Malformation Type 1b: This subtype is distinguished by the lack of the portal vein and a patent ductus venosus (PDV). Collateral vessels that grow between the mesenteric and systemic veins allow blood from the intestines and other abdominal organs to bypass the liver and go straight into the inferior vena cava.

Abernethy Malformation Type 2

The type 2 Abernethy malformation is an uncommon extrahepatic portosystemic shunt with diverse clinical symptoms. It manifests with an intact intrahepatic portal vein, but the venous flow is redirected to the vena cava by an aberrant liver-intestine link. In order to treat this condition, the intrahepatic portal vein can be preserved with surgical closure of the porto-caval shunt.