295 Comparative Evaluation of Risk of Post-ERCP Pancreatitis With Placement of Wing (ViaDuct) and Conventional Plastic Biliary Stents

Abstract

Pancreatitis is the most common complication of ERCP. Biliary stenting has recently been shown to increase risk of post-ERCP pancreatitis (PEP). The reduction in rates of pancreatitis for high-risk patients after pancreatic duct (PD) stenting would suggest that obstruction of the pancreatic sphincter may be causative. With its unique winged shape design with multiple grooves in-between its wings, the Wing Stent (WS) (GI Supply) may theoretically decrease risk of PEP. To compare the safety of WS and conventional plastic stents (CPS)for incidence of PEP. Consecutive patients with biliary pathologies necessitating insertion of WS or CPS during the period 2003-2009 were included. Relevant demographics, clinical, and procedural data were collected. Patients who had at least one WS placed comprised the WS group, while patients who underwent CSP placement only comprised the CPS group. PEP was diagnosed according to established clinical criteria. Fisher's exact test and univariate and multivariate logistic regression were performed to analyze the association of type of stent and other factors with risk of PEP. During the study period, 387 patients (mean age 58.8 years, females 47.1%) underwent 656 ERCP procedures (WS group 80, CPS group 576). Compared to CPS group, risk factors for PEP were significantly more common in the WS group {age <40 yr (p=0.005), SOD indication (p=0.015), history of PEP (p=0.02)}. Biliary sphincterotomy was more commonly performed in the CPS group (<0.001). PEP occurred at equal rate between the WS and CPS groups (3.8% vs. 4.2%, OR= 0.90, p=0.86). Univariate analysis demonstrated several risk factors for PEP: benign indication (OR 4, p=0.02), SOD indication (OR 3.41, p=0.03), PD cannulation (OR 3.92 p=0.001), PD injection (OR 4.01, p=0.001), and biliary sphincterotomy (OR 3, p=0.008). Placement of a biliary stent without biliary sphincterotomy increased risk of PEP (OR 4.16, p=0.005). A dilated bile duct was protective against PEP (OR 0.30, p=0.03). Multivariate analysis also showed that a benign indication (OR 4.76, p=0.015), absence of biliary sphincterotomy prior to stenting (OR 5.3, p=0.002) and PD cannulation (OR 2.78, p=0.018) were significant risk factors for PEP. The risk of PEP was not significantly different between WS and CPS groups (OR 1.01, p=0.98), after adjustment for PEP risk factors. This is the first study to examine safety profile of wing stents. There was no increased risk of PEP with placement of wing stents. A larger study is needed to examine the theoretical advantage of wing stents for decreasing PEP rates.