Primary Needle-Knife Sphincterotomy for Biliary Access in Patients at High Risk of Post-Endoscopic Retrograde Cholangiopancreatography Pancreatitis

Background and Aim. Needle-knife sphincterotomy (NKS) is currently recommended as the second option in cases of difficult cannulation due to its potential higher adverse event rate. However, the clinical outcomes of NKS have not been evaluated as thoroughly as those of the primary cannulation technique. The aim of the current study was to investigate the feasibility, efficacy, and safety of NKS when used for primary access in patients at high risk of developing postendoscopic retrograde cholangiopancreatography pancreatitis (PEP). Methods. Forty patients with one or more risk factors for PEP were prospectively enrolled between June 2018 and November 2019. The cannulation was conducted in all patients using NKS as the primary cannulation technique. Success rate of biliary cannulation, biliary cannulation time, and adverse event rate were assessed. Results. Of the 40 patients enrolled, 34 patients underwent primary NKS after the screening. Nine patients had 1 risk factor for PEP, 7 had 2, 8 had 3, 7 had 4, and 3 had 5. The success rate of biliary access by NKS was 94.1% (32/34). The median procedure time for NKS and the total procedure time for stone removal or biliary drainage were 4.1 minutes (range, 0.5-25.2) and 11.3 minutes (range, 3.8–40.4), respectively. Adverse events occurred in two patients (minor bleeding, n=1; hyperamylasemia, n=1). No patient experienced PEP or perforation. Conclusion. NKS might be feasible as a primary cannulation procedure in patients at high risk of PEP. This trial is registered with KCT0004886 (03/06/2018)