Risk factors and prevention of postoperative pancreatic fistula after insulinoma enucleation:a retrospective study from a high-volume center

BACKGROUND/OBJECTIVES: Enucleation is an effective surgical method to treat pancreatic insulinoma, however, the incidence of clinically relevant postoperative pancreatic fistula (CR-POPF) is high. We aim to investigate the risk factors for CR-POPF which have not been well characterized and develop effective methods to prevent CR-POPF after enucleation. METHODS: This retrospective cohort study included 161 patients diagnosed with insulinoma from June 2016 to July 2020 in Peking Union Medical College Hospital. The risk factors for CR-POPF were evaluated and the role of prophylactic pre-operative pancreatic stent to prevent the occurrence of CR-POPF after enucleation of pancreatic insulinoma were explored. RESULTS: A cohort of 161 insulinoma cases were reviewed. The CT or MRI imaging reports could be tracked in 108 cases. A total of 96 patients underwent surgery, while 81 experienced pancreatic enucleation. Univariate and multivariate analyses showed that the distance from insulinoma to the main pancreatic duct (MPD) ≤2 mm was an independent risk factor for CR-POPF (p = 0.003, OR = 6.011, 95% Cl 1.852-19.512). The pre-operative pancreatic stent substantially reduced the incidence of CR-POPF in patients with tumor located in proximity to (distance ≤2 mm) the MPD (CR-POPF of the stented group vs the non-stented group: 37.5% vs 71.4%, p = 0.028). CONCLUSIONS: The distance from insulinoma to MPD ≤2 mm is a predictive factor for CR-POPF after enucleation. Pancreatic duct stenting may benefit patients with insulinoma in proximity to the MPD by enabling a lower CR-POPF rate, so it should be considered before the enucleation of the insulinoma in proximity to the MPD (distance ≤2 mm).