The clinical impact and risk factors of latent pancreatic fistula after pancreatoduodenectomy

Background Latent pancreatic fistula (LPF) is difficult to diagnose during the early postoperative phase because of initially normal drain fluid amylase (DFA) levels. The present study investigated the clinical significance and risk factors of LPF after pancreatoduodenectomy. Methods A total of 662 patients who underwent pancreatoduodenectomy between 2010 and 2018 were retrospectively analyzed. LPF was defined as pancreatic fistula that developed later regardless of initially low DFA levels. Results Among the 372 patients with DFA <= 375 U/L (three times the upper limit for serum) on postoperative day (POD) 3, LPF occurred in 37 (10%). The rates of postoperative hemorrhaging (11% vs 1.5%), intraabdominal abscess (57% vs 7.2%) and reintervention (46% vs 2.7%) were significantly higher in the patients with LPF than in those without LPF. A multivariate analysis revealed that a body mass index >= 25 kg/m(2), a non-combined portal vein resection, a DFA on POD 1 >= 650 U/L and a C-reactive protein level on POD 3 >= 11 mg/dL were independent risk factors for LPF. Conclusions Latent pancreatic fistula was significantly associated with severe complications and worse outcomes after pancreatoduodenectomy. Early drain removal may be unfavorable for patients with some of these risk factors.