Adverse events after biliary sphincterotomy: Does the electric current mode make a difference? A systematic review and meta-analysis of randomized controlled trials.

Background: Biliary sphincterotomy is an invasive method that allows access to the bile ducts, however, this procedure is not exempt of complications. Studies in the literature indicate that the mode of electric current used for sphincterotomy may carry different incidences of adverse events such as pancreatitis, hemorrhage, perforation, and cholangitis.

Aim: To evaluate the safety of different modes of electrical current during biliary sphincterotomy based on incidence of adverse events.

Methods: We searched articles for this systematic review in Medline, EMBASE, Central Cochrane, Lilacs, and gray literature from inception to September 2019. Data from studies describing different types of electric current were meta-analyzed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The following electric current modalities were evaluated: endocut, blend, pure cut, pure cut followed by blend, monopolar, and bipolar.

Results: A total of 1791 patients from 11 randomized clinical trials evaluating the following comparisons: 1. Endocut vs Blend: No statistical difference in the incidence of bleeding (7% vs 13.4%; RD: -0.11 [-0.31, 0.08], P=0.27, I=86%), pancreatitis (4.4% vs 3.5%; RD: 0.01 [-0.03, 0.04], P=0.62, I=48%) and perforation (absence of cases in both arms). 2. Endocut vs Pure cut: Higher incidence of mild bleeding (without drop in hemoglobin levels, clinical repercussion or need for endoscopic intervention) in the pure cut group (9.2% vs 28.8%; RD: -0.19 [-0.27, -0.12], P<0.00001, I=0%). No statistical difference regarding pancreatitis (5.2% vs 0.9%; RD: 0.05 [-0.01, 0.11], P=0.12, I=57%), perforation (0.4% vs 0%; RD: 0.00 [-0.01, 0.02], P=0.7, I=0%) or cholangitis (1.8% vs 3.2%; RD: -0.01 [-0.09, 0.06], P=0,7). 3. Pure cut vs blend: higher incidence of mild bleeding in the pure cut group (40.4% vs 16.7%; RD: 0.24 [0.15, 0.33], P<0.00001, I=0%). No statistical difference concerning incidence of pancreatitis or cholangitis. 4. Pure cut vs Pure cut followed by Blend: No statistical difference regarding incidence of bleeding (22.5% vs 11.7%; RD: -0.10 [-0.24, 0.04], P=0.18, I=61%) and pancreatitis (8.9% vs 14.8%; RD 0.06 [-0.02, 0.13], P=0.12, I=0%). 5. Blend vs pure cut followed by blend: no statistical difference regarding incidence of bleeding and pancreatitis (11.3% vs 10.4%; RD -0.01 [-0.11, 0.09], P=0.82, I=0%). 6. Monopolar vs bipolar: higher incidence of pancreatitis in the monopolar mode group (12% vs 0%; RD 0.12 [0.02, 0.22], P=0.01).

Conclusion: Pure cut carries higher incidences of mild bleeding compared to endocut and blend. However, this modality might present a lower incidence of pancreatitis. The monopolar mode elicits higher rates of pancreatitis in comparison with the bipolar mode. There is no difference in incidence of cholangitis or perforation between different types of electric current. There is a lack of evidence in the literature to recommend one method over the others, therefore new studies are warranted. As there is no perfect electric current mode, the choice in clinical practice must be based on the patient risk factors.