Clinical comparison between the presence and absence of protein plugs in pediatric choledochal cysts: experience in 390 patients over 30 years in a single center

PURPOSE: The incidence of choledochal cyst (CC) with protein plugs is between 15.5%–40.4%. However, studies on CCs with protein plugs in children are limited. We aimed to analyze the clinical features, surgical findings, and complications of pediatric CCs with and without protein plugs. METHODS: We retrospectively analyzed 390 patients who underwent surgery for CCs between January 1987 and September 2017. The patients were divided into 2 groups: groups A (CC with protein plugs) and B (CC without protein plugs). The presence of protein plugs was evaluated using preoperative images or identified during surgery. RESULTS: One hundred forty-two (36.4%) patients had protein plugs in the pancreaticobiliary duct. The most common initial clinical presentation was abdominal pain, and its incidence was significantly higher in group A (66.2%) than in group B (54.8%) (P = 0.032). The incidence of accompanying pancreatitis was also significantly higher in group A (37.3% vs. 27.0%) (P = 0.040). Anomalous pancreaticobiliary ductal union (APBDU) was found in 261 patients (66.9%) and its incidence was significantly higher in group A (74.6% vs. 62.5%) (P = 0.014). Most protein plugs were found in the cyst (88.0%) and common channel (31.7%). The incidence of early complications was higher in group A; conversely, that of late complications did not differ. CONCLUSION: Approximately 36.4% of the pediatric CC patients were accompanied by protein plugs. Abdominal pain, pancreatitis, and APBDU were more commonly observed among those with protein plugs than among those without; long-term complications did not differ between them.