646 Background: Multiple studies have shown the superiority of biliary metal compared with plastic stents for pre-operative (preop) biliary drainage in pancreatic cancer (PDAC). Despite the importance of preop cross-sectional imaging, particularly in the era of neoadjuvant treatment, there is no data on the impact of such stents on the quality of preop cross-sectional imaging. We hypothesis, that biliary metal stents negatively impact the accuracy of preop cross-sectional imaging in pancreatic cancer, with unknown impact for the adequacy of surgical candidacy. Methods: Data of all patients undergoing pancreatic resection for PDAC between 1/1/2012 and 1/1/2018 was retrospectively abstracted. Clinical staging based on preop cross-sectional imaging following biliary stent placement (within 2 months prior surgical resection) was compared with the surgical pathology (staging gold standard). Accuracy of clinical and surgical pathology staging was compared. Logistic regression was performed to control for biliary stent type, neoadjuvant treatment and patient baseline characteristics including BMI and type of imaging. Results: 312 patients underwent pancreatic resections. 118 patients required preop biliary drainage in setting of PDAC, including 92 ERCPs of which 83 were successful (46 plastic and 37 metal stents). 76 patients underwent neoadjuvant chemoradiation therapy. Surgical pathology revealed following stages: 0 n = 4, 1A n = 5, 1B n = 8, 2A n = 20, 2B n = 24, 3 n = 1, 4 n = 14. 96% underwent preop CT and 4% MRI pancreas protocol imaging. Exact correlation between clinical and surgical pathology was present in only 48% of cases (57% plastic, 46% metal stent), with 28% of clinical T overstaging, 4% clinical T understaging, 16% clinical N understaging and 4% unable to stage due to artefacts. More importantly, 8% patients were incorrectly staged to be surgical candidates (14% plastic, 6% metal). Controlling for stent type, neoadjuvant treatment and BMI did not impact preop cross-sectional imaging accuracy. Conclusions: Despite their impact on preop cross-imaging biliary metal stents did not negatively impact the accuracy and patient selection for surgical candidacy compared with biliary plastic stents in PDAC.
Safety and efficacy of self-expanding metal stents for biliary drainage in patients receiving neoadjuvant therapy for pancreatic cancer
