Discussion:
Choledochal cysts are infrequent congenital malformations characterized by cystic dilatations of the biliary tree(1). These dilatations can be extra-hepatic, intrahepatic or both. The incidence of choledochal cysts in Asian population is 1 in 1000 live births with predominance in females. In western countries, the incidence ranges from 1:100,000 to 1:150,000 in the United States, 1 in 2 million in the United Kingdom(12). In Uganda, so far this is the second case of giant choledochal cyst in a young female adult that has been managed successful at Mbarara Regional Referral Hospital (13). A study done in Uganda by Odongo et al., shows that choledochal cysts account for 1.4% of the causes of extra-hepatic obstructive jaundice which is very low hence making it rare case(14)
Giant choledochal cyst refer to the huge cysts with a diameter of greater than 10 cm(15). For our case, intra-operatively, the cyst was measuring 30cm x 25cm x 25cm which is big.
The primary diagnostic modality is by abdominal ultrasound scan followed by CT scan and the MRI(16). The associated anomalies are biliary atresia, gallbladder atresia, hepatic fibrosis and those of pancreatico-biliary ductal system. MRI and MRCP have a conclusive role in confirming ultrasound scan diagnosis(5). This is also done to evaluate anatomy and identify complications related to the cyst(5). In our case, only imaging modalities available were abdominal ultrasound scan and the CT-scan. The abdominal ultrasound sound scan was used to screen the patient and identify the choledocal cyst. The CT-Scan was used to confirm our diagnosis and classify our cyst under Tonadi classification and it was type IA choledochal cyst.
Although studies have documented the use of ERCP in certain centers of Uganda in the management of hepatobiliary conditions, in our center (MRRH), there is absence of these modern invasive machines that can help us in both diagnosis and treatment of choledochal cysts. Therefore we rely on open surgery for everything which in some instances increases the chances of complications for example along hospital stay(17).
The treatment of choledochal cyst is an initial control of complications then followed by the primary surgery of the cause. Presently the most popular and accepted surgical intervention is by total excision of the choledochal cyst and restore the biliary enteric drainage into the duodenum either via Roux-en-Y hepatico-jejunostomy or Braun hepatico-jejunostomy(18). The later approach was used in our patient to reconstruct a connection between common hepatic duct and a loop of jejunum 40 cm from the ligament of treitz(10).