Defining an optimal surveillance strategy for patients following choledochal cyst resection: results of a systematic review

Background Choledochal cysts should be treated with complete surgical resection, or, rarely liver transplantation. Treated patients can remain at risk of developing metachronous cholangiocarcinomas and lifelong follow up is indicated. However, there is no agreement on what constitutes an acceptable follow up strategy. This review was undertaken to develop an evidenced based surveillance strategy. Methods A systematic review of MEDLINE, EMBASE, PubMed, Web of Science, and Google Scholar was undertaken for reports (published up to 10 September 2021) describing late biliary complications and development of metachronous cholangiocarcinoma following choledochal cyst resection. Results Twenty-five publications described 74 metachronous cholangiocarcinomas occurring in 3911 patients (overall incidence 2%). Cancers developed commonly at the hepatic hilus and were diagnosed after a median interval of 92 months (range 9-249 months) after the initial resection. While reporting is incomplete, the majority of cholangiocarcinomas developed following resection of type I and type IV cysts with few metachronous cancers recorded after treatment of type II or III cysts. Peak age range for presentation with metachronous cholangiocarcinoma is in the twenties following cyst resection in childhood suggesting that patients are at greatest risk for metachronous tumour development for up to 20 years (240 months). Conclusion A surveillance strategy is proposed for patients treated primarily for cyst types I and IV and unresected type V using annual liver function tests, Ca 19-9 measurement and biannual ultrasound assessment for 20 years post cyst resection, with biannual liver function testing, Ca 19-9 measurement and three yearly ultrasound assessment thereafter.