Portal Hypertension Shunt Surgery at MUSC Children's Health Offers Solutions for Children with Complex Liver Disorders

The MUSC Health Pediatric Liver Program is South Carolina’s tertiary referral center for children with complex liver and biliary disorders. Along with being the state’s only organ transplant center, MUSC Health is one of the few pediatric centers in the US (and the only one in South Carolina) that performs surgical shunt surgery and endovascular procedures in children with portal hypertension caused by portal venous thrombosis or congenital portosystemic shunts. Children with these conditions typically have a normal functioning liver. As such, these unique surgical procedures offer a first-line alternative to high-risk liver transplants. For liver transplant patients, the shunt surgery also offers a means to augment an existing transplant.

Children with portal venous thrombosis have a clot in the portal vein that carries blood from the intestines to the liver. Children with congenital portosystemic shunts have a malformation of blood vessels that divert blood away from the liver instead of going through it. Left untreated, these disorders can lead to dysfunction of other organ systems and/or a dangerous condition called portal hypertension where there is increased pressure within the portal vein that can cause multi-system damage. The goal of the portal hypertension shunt surgery is to restore blood flow into the liver by bypassing the clot or closing the abnormal shunt and creating a new route into the liver using a healthy blood vessel taken from another part of the patient’s body. Unlike with liver transplants, there is no need for lifelong use of anti-rejection immunosuppressant medications that can make children susceptible to cancers, infections, and various organ diseases.

For the past three years, a multidisciplinary MUSC Health team lead by Nagraj Kasi, M.D., Satish Nadig, M.D., Ph.D, Vinayak Rohan, M.D., and Ricardo Yamada, M.D. has been successfully conducting these specialty procedures in patients as young as six months old. Dr. Kasi, a pediatric gastroenterologist, conducts the pre- and post-surgical evaluations, Drs. Nadig and Rohan, adult and pediatric multiorgan transplant surgeons, perform the shunt surgery, and Dr. Yamada, an interventional radiologist, performs adjuvant endovascular procedures. To date, all patients who have undergone the surgical and endovascular procedures are doing well, with resolution of portal hypertension.

“The biggest factors to our success are the teamwork and collaboration that we have established within MUSC Health and with physicians throughout the state,” says Kasi. “We have a dedicated team with unique skill sets that are not found everywhere and we’re all invested in applying our expertise to help children with these complex hepatobiliary conditions.”

Children with portal venous thrombosis and congenital portal systemic shunts are often asymptomatic and diagnosed incidentally (e.g., imaging for an unrelated accident). When symptoms are present, these include abdominal pain, elevation of liver enzymes, an enlarged spleen, and gastrointestinal bleeding. Once diagnosed, Dr. Kasi recommends that the patient be assessed for eligibility to receive the portal hypertension shunt surgery as soon as possible.

“We want to conduct these surgeries before there is long-term multi-system damage,” explains Kasi. “Children who progress to portal hypertension can develop esophageal varices (abnormal vessels in the esophagus or stomach that easily bleed) which leads to an enlarged spleen, hepatopulmonary syndrome which reduces oxygen levels in the blood, portopulmonary hypertension which increases blood pressure in blood vessels to the lungs, or encephalopathy which slows brain function leading to behavioral, cognitive, and fine motor deterioration.”

Patients referred to the MUSC Health Pediatric Liver Program undergo a thorough evaluation for eligibility, a process that (including surgery) takes a month or less to complete. Multiple testing modalities (e.g., blood work, imaging, liver biopsy) are used to assess liver function and exclude for chronic liver disease and significant liver damage. To determine the urgency and best treatment course, the pediatric gastroenterology, cardiology, and interventional radiology teams assess the severity of multi-system effects and consider all available treatments. As part of risk management, the hematology team evaluates the patient’s risk factors for developing blood clots and plans mitigation strategies (e.g., using blood thinners). Overall, if a patient has a functional liver, manageable risks factors, and dangerous symptoms that cannot be managed with medication or addressed with interventional radiology (e.g., using stents to restore blood flow), then the patient is a candidate for the portal hypertension shunt surgery.

The shunt surgery is a technically challenging operation that takes several hours to complete and, depending on where the patient’s specific blockage is located, different types of shunt surgeries (e.g., Warren’s splenorenal, Meso-Rex) are needed. Because of the rarity of pediatric portal hypertension, the expertise required to determine and perform the appropriate type of shunt surgery is limited to pediatric transplant surgeons.

“Many surgeons have never even seen a shunt surgery done,” explains Nadig. “Historically, these surgeries were done in adults but, with the advent of interventional radiology, shunt surgeries became obsolete for adults because the technology and expertise shifted to interventional radiology. However, for small children, shunt surgeries remain the better treatment option. Compared to stents (which are mostly developed for adults and have a limited lifespan), the patient’s own tissue provides a better fit and is more durable in the long run.”

After surgery, the patient is monitored at the MUSC Health Pediatric Liver Program for at least one year to ensure that the newly created shunt healed without clotting, that blood flow into the liver is restored, and that all symptoms of multi-system effects are improving. If the new shunt clots, the interventional radiology team is consulted for endovascular methods to reopen the shunt without a major surgery. Once the post-surgical evaluation is cleared, the patient is transferred back to their gastrointestinal physician, with whom the MUSC Health communicates regularly throughout the process.

Along with providing specialized surgical procedures, the MUSC Health Pediatric Liver Program is also establishing a reputation for its bench to bedside approach and out-of-the box thinking. To prevent the lifelong side effects associated with anti-rejection immunosuppressant medications, Dr. Nadig and his research team at the Lee Patterson Allen Transplant Immunobiology Laboratory are developing a nanoparticle that has anti-rejection medication on the inside of it. By targeting the nanoparticle directly to the transplanted organ, the body's immune system stays intact.

With capabilities and specialized expertise comparable to larger US pediatric centers, the MUSC Health Pediatric Liver Program enables patients with complex medical needs to look within the southeast region for solutions and comprehensive care.