S83 Fully Covered vs Uncovered Self-Expanding Metal Stents for the Treatment of Distal Malignant Biliary Obstruction in the Setting of Locally Advanced Pancreatic Cancer

Abstract

Introduction: Self-expanding metal stents (SEMS) are preferred for the treatment of distal biliary obstruction (dMBO) caused by pancreatic cancer. Optimizing biliary drainage in the neoadjuvant period while patients await definitive surgical treatment is essential. The aim of this study is to compare clinical outcomes of patients who underwent fully covered (FCSEMS) versus uncovered (UCSEMS) placement for the treatment of dMBO due to locally advanced pancreatic cancer (LAPC). Methods: Consecutive patients who underwent biliary SEMS placement for treatment of dMBO in the setting of LAPC were identified from a single, tertiary care center between May 2017 and May 2021. Patients were categorized into FCSEMS or UCSEMS cohorts based on the type of stent placed during index ERCP. UCSEMS included WallFlex (Boston Scientific,Boston,MA) and Flexxus (ConMed,Utica,NY). Primary outcomes were clinical success, overall incidence of adverse events (AEs), and need for unplanned endoscopic reintervention. Secondary outcomes included stent patency, type of AEs, and overall survival. Results: 817 cases of ERCP with SEMS placement were reviewed to identify 187 patients with dMBO due to LAPC. 35 (18.7%) patients underwent FCSEMS placement and 152 (81.3%) UCSEMS (49 WallFlex, 103 Flexxus). High rates of clinical success were seen in both cohorts (92.1% UCSEMS vs. 97.1% FCSEMS, p = 0.29). (Table) Stent patency was significantly longer in patients who underwent FCSEMS placement (Figure 1A). There was no difference in rates of occlusion or time to occlusion between the two UCSEMS models. AE rates were significantly higher after UCSEMS placement (32.9% vs. 14.3%, p = 0.03) as was need for unplanned reintervention (29.0% vs. 5.7%, p = 0.004), largely driven by SEMS occlusion (28.9% vs. 2.9%, P = 0.001) in the setting of tissue ingrowth (42/44 cases). A similar number of patients underwent surgical resection (UCSEMS 55.9% vs. FCSEMS 65.7%, p = 0.29) at similar interval after stent placement (UCSEMS 7.0 vs. FCSEMS 6.0 months, p=0.57). All-cause mortality and duration of survival was not different between the two groups (Figure 1B). Conclusion: FCSEMS were associated with longer patency times and fewer interventions in a cohort of patients with LAPC that otherwise exhibited similar survival and rates of surgical intervention. Additional studies are needed to evaluate cost implications, but this data suggests placement of a FCSEMS may be preferred to UCSEMS in the palliation of dMBO in anatomically amenable patients with LAPC.Figure 1.: Cumulative patency time. Stent patency was defined as the interval between the time of stent insertion and the time of biliary reintervention because of stent dysfunction or the end of the follow-up. Patients without stent obstruction were censored at the time of surgery, last follow-up or death. 1B: Overall survival Table 1. - Clinical outcomes of patients who underwent metal biliary stent placement for the management of locally advanced pancreatic cancer UCSEMS n=152 FCSEMS n=35 P Value Clinical Success 140 (92.1) 34 (97.1) 0.29 Adverse Events 50 (32.9) 5 (14.3) 0.03 Stent Occlusion 44 (28.9) 1 (2.9) 0.001 PEP 8 (5.3) 2 (5.7) 1.00 Stent Migration 3 (2.0) 2 (5.7) 0.24 Cholecystitis 1 (0.7) 0 (0.0) 1.00 Unplanned reintervention 44 (29.0) 2 (5.7) 0.004 Median time to unplanned reintervention (months) 4.4 (3.0-5.6) 4.3 (3.6-5.1) 0.81 Median time to stent occlusion (months) 4.4 (3.0-5.6) 5.9 (5.9-5.9) 0.73 Median stent dwell time (months) 7.0 (5.0-8.7) 6.0 (3.5-8.5) 0.16 Median follow up time (months) 15.6 (8.8-24.6) 22.4 (8.3-27.9) 0.23 Surgical resection 85 (55.9) 23 (65.7) 0.29 Median time to surgical resection (months) 7.0 (5.0-8.9) 6.0 (4.4-8.2) 0.57 Death 84 (55.3) 22 (62.9) 0.41 Values are presented as median (IQR) or n (%). UCSEMS uncovered self-expandable metal stent FCSEMS fully covered self-expandable metal stent PEP post-ERCP pancreatitis.