American Board of Surgery Qualifying Exam (ABS QE) Practice Test

Type 1 choledochal cyst is characterized by fusiform dilation of the common bile duct. This type typically presents as a type of cystic enlargement that primarily affects the extrahepatic bile duct, leading to an elongated and smooth-walled structure resembling a ballooning of the duct. The enlargement can vary in size but is often observed in the lumen of the bile duct without significant proximal or distal structures being involved.

Understanding this type is crucial for diagnosis and management since it can lead to complications such as bile duct obstruction, pancreatitis, or cholangitis if left untreated. The distinction of Type 1 is significant in the context of surgical planning, as it often requires resection and anastomosis to preserve the function of the biliary tree while minimizing the risk of associated complications.