[Congenital portosystemic shunt. The Abernethy malformation]

Abstract

Background: Congenital portosystemic shunt (CEPS) is a rare condition that was first reported by John Abernethy in 1793. Two types of CEPS are described: type I (side to end anastomosis) or congenital absence of the portal vein, and type II (side to side anastomosis) with portal vein supply partially conserved. Type I CEPS is usually seen in girls and associates multiple malformations as polysplenia, malrotation, and cardiac anomalies. Type II is even rarer with no sex preference and no malformations associated. Hepatic encephalopathy is a common complication of both types in adulthood. Liver transplantation is the only effective treatment for symptomatic type I CEPS. A therapeutic approach for type II could be surgical closure of the shunt.

Objective: To analyse our experience in diagnosis and management of portosystemic shunts.

Methods: We report 4 cases of CEPS (3 type I and 1 type II) diagnosed between January-1997 and March-2005 in our department.

Results: We present 4 patients with ages at diagnosis ranging from 0 to 28 months, 3 type I CEPS (2 boys and 1 girl) and 1 boy type II. The type I girl was prenatally diagnosed at 12 weeks of gestation. Initial clinical signs in type 1 boys were splenomegaly and hypersplenism, both with normal pondo-statural growth. No polysplenia or cardiac anomalies were assessed. One of them presented mild developmental delay, dismorphic features and facial telangiectasias. He had normal coagulation tests with chronic hepatic dysfunction (high transaminases) and regenerative nodular lesions were seen by imaging techniques. The other type I patient had hypoprothrombinemia, tendency to capillary bleeding (haematomas and epistaxis) with preserved liver function. Both patients have developed mild portal hypertension and present steatosis signs at liver biopsy. The type I girl presents a 21 trisomy and associates a cardiac anomaly (interauricular communication). Her hepatic function test are normal but liver calcifications can be seen by ultrasound. Type II child associates hypospadias but he has no clinical sigh or symptom related to the shunt. In our three cases diagnosis was suggested by conventional and Doppler ultrasound and confirmed by angio-resonance imaging. All our patients are included in a meticulous clinical and radiological follow-up with no need of surgical treatment for the shunt until now.

Conclusions: Although diagnosis of these malformations could be casual we have to think about CEPS in children presenting unspecific liver disease. Magnetic angio-resonance imaging is actually the best diagnosis methods for CEPS. These patients have a high risk for developing hepatic encephalopathy and portal hypertension, so a careful follow-up is required although surgery is not usually needed until adulthood.