The Todani classification: still useful after all these years?

Abstract

Objective: The Todani classification for choledochal cysts (CCs) has been in use for almost 40 years. We hypothesize that the Todani classification does not serve much use in accurately describing congenital CCs. Methods: The clinical and operative findings of 57 adult and pediatric patients who were treated for CCs from 1979 to 2016 were retrospectively analyzed. All available preoperative imaging and radiology reports were reviewed to verify the morphologic condition of the presenting biliary anomalies. Results: The presenting symptom in adult patients (n = 39) was pain (69%) and in pediatric patients (n = 18) was jaundice (56%). Based on the Todani classification, we found 45 cases of type I (79%) and 7 cases of type IVA (12%) which made up 91% of the total cases examined. The remaining CC cases did not fit into the other categories of Todani type II, III, or V and are listed in Table 1. In 25% of patients, reference to type I and type IVA or “type I/IV” were all used interchangeably in describing the CC despite clear assessment on radiographic imaging. Conclusion: The Todani classification is not practical, falsely grouping together all abnormalities of the biliary tree as choledochal cysts. Types I and IVA are often indistinguishable, and should be combined under the name CC. For the remaining spectrum of biliary tree abnormalities, both the rarely seen Todani subtypes and significant portion not encompassed by Todani, a descriptive characterization is needed.Table 1Choledochal cysts outside of the Todani classification.Patient no/age sexSymptomLocation of CCOperation1/61FPainCentral CC from anterior sector bile ductCentral hepatectomy2/51FJaundiceCC from left hepatic bile ductCholecystectomy, Left hepatectomy3/36FPainIntrapancreatic CC involving union of CBD and PDWhipple pancreaticoduodenectomy4/1MJaundice, secondary biliary cirrhosisExtrahepatic biliary atresia with CCLiving donor liver transplant (segments 2, 3)5/1MDown Syndrome screening USCC in segment 4b/5 of liverHepatotomy and cyst excisionCC – choledochal cyst; CBD – common bile duct; PD – pancreatic duct; US - ultrasound Open table in a new tab CC – choledochal cyst; CBD – common bile duct; PD – pancreatic duct; US - ultrasound