The clinical importance of the trimethadione tolerance test as a method for quantitative assessment of hepatic functional reserve in patients with biliary atresia

Background: The trimethadione (TMO) tolerance test was performed to evaluat e its usefulness in the assessment of hepatic functional reserve in patient s with biliary atresia. Method: Nineteen patients with biliary atresia after hepatic portoenterosto my (age range: 2 months to 25 years; sex: 6 males and 13 females) were stud ied. The study was performed in the morning after a 12-h fast. TMO was give n orally, at a dose of 4 mg/kg, with 5 mL of 5% glucose 2 h before breakfas t. Blood samples (0.5 mL) were collected to determine serum TMO and dimetha dione (DMO), a metabolite of TMO, levels 4 h after the administration of TM O. TMO and DMO were measured by a gas-liquid chromatographic method. Results: A higher total bilirubin level (over 1 mg/dL) in patients with jau ndice was reflected in the smaller serum DMO/TMO ratio 4 h after the oral a dministration of TMO. In addition, these patients with total bilirubin leve ls of 1 mg/dL or less had a significantly lower DMO/TMO ratio than the cont rol group (healthy subjects). The serum DMO/TMO ratio showed a close correl ation with the Child-Pugh score, which is used for overall evaluation of se verity of cirrhosis and Mayo risk scores for primary biliary cirrhosis in a dults (0.856, P < 0.01 and 0.788, P < 0.01, respectively). The TMO tolerance test shows the benefit of performing a relatively early t est of dynamic liver function to evaluate hepatic functional reserve in pre - and post-operative biliary atresia patients.