Estimation of postoperative fat absorption using the 13C mixed-triglyceride breath test in children with choledochal cyst

No previous studies have focused on postoperative fat malabsorption in children with choledochal cyst (CC) who undergo cyst excision and Roux-en-Y (RY) hepatico-jejunostomy (HJ), a combination of procedures that can lead to the non-physiological mixture of food and bile juice. To examine the effect of RYHJ with cholecystectomy on the fat absorption ability of children with CC, we estimated postoperative fat-absorption ability using the carbon 13-labeled mixed triglyceride (C-13-MTG) breath test. Twelve postoperative children with CC and 12 normal control children were administered C-13-MTG orally and asked to give breath samples at six time points: once before the C-13-MTG ingestion and at five 60-min intervals post-ingestion. Fecal chymotrypsin activity and fecal fat excretion were also measured. The delta value of breath (CO2)-C-13 at 3, 4, and 5 h after administration and the 5-h cumulative breath (CO2)-C-13 were significantly lower in the CC children than in the controls. There were no significant differences in the fecal chymotrypsin activity or fecal fat excretion of the two groups. Conclusion. Occult fat malabsorption occurs in patients with CC after RYHJ, even in the absence of clinical symptoms or abnormal laboratory data.