Congenital Portosystemic Shunts (Abernethy Malformation)

What Is a Congenital Portosystemic Shunt (Abernethy Malformation)?

The Abernethy malformation, or a congenital (from birth) portosystemic venous shunt, is a rare deformity of the blood vessels in the abdomen. The malformation involves an abnormal connection between the blood vessels (veins) of the intestines and the body’s general blood circulation, bypassing the liver. This condition can lead to complications such as pulmonary hypertension (a serious heart condition), pulmonary AVMs (abnormal blood vessel connections in the lungs) and elevated ammonia levels that can affect brain function and nodules, or lesions, on the liver.

Some children with the condition have no symptoms at all, and the defect is discovered accidentally when radiology tests such as X-rays or ultrasounds are done for another reason.

Often, surgical interventions are needed to treat and cure this condition. Dr. Riccardo Superina, head of transplant surgery at Lurie Children’s, and the vascular malformation team at Lurie Children’s have experience with more than 60 children with this rare disorder.

How Are Abernethy Malformations Diagnosed?

Abernethy malformations are sometimes discovered during a prenatal ultrasound done as early as 14 weeks, or it may be discovered during evaluations for other prenatal conditions.

The condition may also be diagnosed later in a child’s life, as children with the condition may present no symptoms, and become aware of the condition only when undergoing imaging for a different condition.

Still, other children may have several serious symptoms of Abernethy malformations.

Newborns with the condition may show symptoms of liver disease, including jaundice, or a yellowish appearance on their skin and whites of their eyes; and hypoglycemia, or very low blood sugar.

Children with the condition may have liver tumors or neurologic conditions such as attention deficits or encephalopathy (altered brain function.) Other symptoms of Abernethy malformations include hepatopulmonary syndrome, a lung complication that can cause shortness of breath and low oxygen levels in the blood; and portopulmonary hypertension, or high blood pressure that affects the lungs and heart and can lead to exercise intolerance and heart failure.

Lurie Children’s physicians can perform an exam to determine the proper diagnosis, which is likely to include a blood draw to observe the child’s liver function. Imaging or CT scans of the abdomen may also be necessary as part of the exam.

How Are Abernethy Malformations Treated at Lurie Children's?

If a child is diagnosed with the Abernethy malformation, the location, length and width of the shunt will determine the best treatment options.

In some cases, the shunt can close on its own, requiring only occasional check-ups with a physician.

Sometimes surgery is necessary to close the portal shunt. Depending on the circumstances, interventional radiology experts can block the shunt in a minimally invasive procedure.

If an open procedure is necessary, is often done in two stages, which involves directing blood flow toward the dysfunctional portal vein. The second operation, usually done 5-7 days later, is when the surgeons close the occlude the shunt completely.

Each operation takes about four to five hours. Often patients stay in the Lurie Children’s Pediatric Critical Care Unit, or PICU, for the days between the two surgeries. In some circumstances, the patient remains sedated for that entire time.

What Is the Recovery Like After Surgery for the Abernethy Malformation?

Following surgery, patients are likely to stay in the hospital for at least two weeks. In some cases, they will need to be carefully monitored in the Pediatric Critical Care Unit. Recovery from the procedures can take longer if the patient’s initial symptoms included pulmonary hypertension.

Once patients are able to leave the hospital, they will be monitored through outpatient clinic appointments.

What Are the Outcomes After Surgery for the Abernethy Malformation?

Patients who had surgical procedures usually have follow-up appointments every three months following surgery for a year. Then, follow-ups usually occur every 6 to 12 months for five years.

During these visits the doctor will monitor for other shunts, as sometimes once the main shunt a patient has is occluded, a secondary, more minor shunt is uncovered. Often, these minor shunts can be addressed with interventional radiology.

Children often recover well from procedures to correct the Abernethy malformation and go on to live full lives.