Successful Management of a Post-Choledochal Cyst Excision Pancreatic Fistula in an Adult Patient: A Case Report and Literature Review on Risk Factors.

Choledochal cyst is a premalignant condition and surgical excision with biliary enteric anastomosis is the standard of care. Surgical treatment in adults may be difficult due to associated biliary pathology and high incidence of postoperative complications is reported. Postoperative pancreatic fistula (POPF) is a rare early complication following choledochal cyst excision.  A 23-year-old male patient was operated for a Todani type IV-A choledochal cyst with anomalous pancreaticobiliary junction. Cyst excision with hepaticojejunostomy was performed. Distal stump closure was technically challenging due to extreme thickening of the cyst wall with neovascularization. On postoperative day 2, patient developed tachycardia and progressive tachypnea with 200 mL of pancreatic fluid in the drain. Endoscopic pancreatic stenting was attempted but was technically not possible. At reexploration, leak from oversewn distal cyst stump was identified and the suture line was reinforced. After the second surgery the patient was hemodynamically stable but continued to have a low output pancreatic fistula for few days which was managed conservatively successfully. We conducted a review of English literature with an aim to identify the risk factors and predictors of pancreatic fistula following cyst excision. An electronic search was performed in Medline and Google Scholar during September 2020 and available literature since January 2000 were reviewed. The keywords used were "pancreatic fistula" and "choledochal cyst."  Preoperative cholangiography (magnetic resonance cholangiopancreotography/endoscopic retrograde cholangiopancreatography) is essential to know the extent of cyst and delineate biliary pancreatic junction. Literature review including our case revealed that Todani type I-c, type IV, and forme fruste type of choledochal cyst are at high risk of pancreatic injury and POPF. Recurrent cholangitis makes excision technically more challenging and complete removal is not always possible.  Postoperative pancreatic fistula can be anticipated in select group of patients with high-risk preoperative findings. Chronic inflammation due to recurrent cholangitis promotes scarring and neovascularization which adds to surgical complexity. Operative technique in these high-risk patients needs further refinement.