Very rare: prevalence estimated at 1/30,000 births. It consists in a direct communication between the portal network and the inferior caval vein or one of its afferents, probably due to an incomplete involution of the vitelline veins

.

Different types:

- intrahepatic shunts: abnormal connections between a branch of the portal vein and the hepatic veins or the IVC, including the  ductus venosus of Arantius

• type 1: right portal vein => inferior vena cava
• type 2: single or multiple shunt between a portal branch and a hepatic vein in a lobe of the liver
• type 3: aneurysmal shunt between a portal branch and a hepatic vein
• type 4: multiple shunts between a portal branch and a hepatic vein in several lobes
• type 5: persistence of the ductus arteriosus

- extrahepatic shunts: communication between the portal vein and the IVC:

• type I: the portal vein is drained in the IVC and there is no intrahepatic portal vein (Abernethy malformation)
• type Ia: the superior mesenteric vein and the splenic vein drain separately into the inferior vena cava
• type Ib: the superior mesenteric vein and splenic vein form a common trunk that drains into the inferior vena cava
• type II: laterolateral anastomosis between the portal vein and the IVC: intrahepatic portal branches are hypoplastic or normal: this condition is often associated with heterotaxy with left isomerism (see this term) and is called the portal venous return anomaly.

The age of diagnosis is highly variable: from the neonatal period to early childhood.

The signs and possible symptoms are:

-        a hypergalactosemia (neonatal screening)

-        hyperammonemia with signs ranging from hepatic encephalopathy to behavioral problems

-        neonatal cholestasis

-        hepato-pulmonary syndrome

-        porto-pulmonary hypertension

-        a liver tumor: adenomas or nodular hyperplasia localized or regenerative, which usually regress when the shunt is interrupted

-        the diagnosis is sometimes made during an antenatal echography.

Other cardiovascular malformations are sometimes associated: ASD, coarctation of the aorta, malformation of the IVC, etc.

The treatment is controversial:

-        most of the intrahepatic shunts close spontaneously and without any sequelae before 2 years of age.

-        intrahepatic or extrahepatic shunts type 1: liver transplantation

-        in case of signs of encephalopathy or hepato-pulmonary syndrome, one can perform a ligature or embolization of the extrahepatic shunt (type 2) or embolization of intrahepatic shunts. However, these treatments must be made with caution because they can cause acute portal hypertension in case of hypoplasia of the intrahepatic portal network. It is therefore recommended to perform an occlusion test (balloon or clamp) and measure portal pressure before permanently closing the shunt.

Anesthetic implications:

check liver function and the absence of hepato-pulmonary syndrome or pulmonary arterial hypertension; absence of first-pass effect for the medicaments administered orally or IV.

References : 

•    Ersch J, Bäzinger O, Braegger C, Arbenz U, Stallmach T. 
  An infant with pulmonary hypertension due to congenital porto-caval shunt. 
  Eur J Pediatr 2002; 161:660-2.

-     Kim MJ, Ko JS, Seo JK, Yang HR, Chang JY, Kim GB, Cheon J-E, Kim WS. 
Clinical features of congenital portosystemic shunt in children. 
Eur J Pediatr 2012 ; 171 : 395-400.

-        Passalacqua M, Lie KT, Yarmohammadi H. 
Congenital extrahepatic portosystemic shunt (Abernethy malformation) treated endovascularly with vascular plug shunt closure. 
Pediatr Surg Int 2012; 28: 79-83.

-         Law YM, Mack CL, Sokol RJ, Rice M, Parsley L, Ivy D. 
Cardioplumonary manifestations of portovenous shunts from congenital absence of the portal vein: pulmonary hypertension and pulmonary vascular dilatation. 
Pediatr Transplantation 2011; 15: E162-8.

-         Hubert G, Giniès J-L, Dabadie A, Tourtelier Y, Willot S, Patiente D, Lefrançois T, Caldari D. 
Shunts porto-systémiques congénitaux : expérience du Grand-Ouest sur cinq ans. 
Arch Pédiatr 2014 ; 21 : 1187-94.

-        Takechi K, Kitamura S, Fujii S, Soutani M, Yorozuya T, Nagaro T.
Delayed emergence from anaesthesia in a patient with agenesia of the ductus venosus.
Anaesthesia Cases 2014; 2: 80-3

-        Uike K, Nagata H, Hirata Y, Yamamura K, Terashi E et al.
Effective shunt closure for pulmonary hypertension and liver dysfunction in congenital portosystemic venous shunt.
Pediatr Pulmonol 2018; 53: 505-11.

-        Cytter-Kuint R, Slae M, Kvyat K, Shteyer E.
Characterization and natural history of congenital intrahepatic portosystemic shunts.
Eur J Pediatr 2021; 180:1733-7.

Updated: May 2021