External biliary drainage before choledochal cyst treatment in a very low birth weight infant.

Choledochal cysts (CC) are congenital biliary tract dilatations. Infantile CC (IFCC) in very low birth weight (VLBW) infants is rare. This is a case of a huge IFCC presented in VLBW preterm infant managed with external biliary drainage prior to definitive treatment. Electrolyte imbalance, poor weight gain, and infections were managed during external biliary drainage maintenance. Choledochal cyst excision and Roux-en-Y hepaticoenterostomy were successfully performed when the infant weighed 4.9 kg 5 months later. Delayed definitive treatment with external biliary drainage could be a feasible alternative for managing CC in low-birth-weight infants.