Effect of surgical portosystemic shunt on prevalence of minimal hepatic encephalopathy in children with extrahepatic portal venous obstruction: assessment by magnetic resonance imaging and psychometry.

OBJECTIVE

The aim of this study was to evaluate the effect of surgical portosystemic shunt (PSS) on the prevalence of minimal hepatic encephalopathy (MHE) in patients with extrahepatic portal venous obstruction.

PATIENTS AND METHODS

Forty-two children with extrahepatic portal venous obstruction (17 with surgical PSS, 25 without surgical shunt) and 20 healthy children were evaluated with blood ammonia (BA), psychometry, H magnetic resonance spectroscopy, critical flicker frequency (CFF), and diffusion tensor imaging. Serum tumor necrosis factor-α and interleukin-6 were measured in 10 patients and 8 controls.

RESULTS

Patients with surgical PSS had significantly higher BA and glutamine/creatine on H-MR spectroscopy than those without surgical shunt. Both groups of patients had significantly higher BA and glutamate/creatine than controls. Myoinositol was reduced in patients with surgical PSS. MHE was present in 41% cases with and 32% cases without surgical PSS (p-ns). Raised mean diffusivity on diffusion tensor imaging signifying low-grade cerebral edema was seen only in MHE cases. Patients had significantly higher serum tumor necrosis factor-α and interleukin-6 levels than controls. CFF was abnormal in 5 of 15 patients with MHE.

CONCLUSIONS

Patients with surgical PSS have significantly higher BA and Glx/creatine than those without surgical PSS. MHE prevalence was higher in surgically shunted than in the nonshunted patients, but the difference was not significant. Cerebral edema is present in patients with MHE. CFF has limited diagnostic utility for MHE in children.