title: Comparison of the influence of plastic and fully covered metal biliary stents on the accuracy of EUS-FNA for the diagnosis of pancreatic cancer.
abstract: OBJECTIVE
  Prior studies have reported that the presence of prior biliary stent may interfere with EUS visualization of pancreatic tumors. We aimed to compare the influence of the biliary plastic and fully covered self-expanding metal stents (CSEMS) on the accuracy of EUS-FNA cytology in patients with solid pancreatic masses.
  
  
  METHODS
  We conducted a retrospective study evaluating 677 patients with solid pancreatic head/uncinate lesions and a previous biliary stent in whom EUS-FNA was performed. The patients were stratified into two groups: (1) those with a plastic stents and (2) those with CSEMS. Performance characteristics of EUS-FNA including the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were compared between the two groups.
  
  
  RESULTS
  The frequency of obtaining an adequate cytology by EUS-FNA was similar in both the CSEMS group and the plastic stent group (97 vs. 97.1 % respectively; p = 1.0). The sensitivity, specificity, and accuracy of EUS-FNA was not significantly different between patients with CSEMS and plastic stents (96.8, 100, 100 % and 97.3, 98, 99.8 %, respectively). The negative predictive value for EUS-FNA was lower in the CSEMS group compared to the plastic stent group (66.6 vs. 78.1 % respectively; p = 0.42). There was one false-positive cytology in the plastic stent group compared to none in the CSEMS group.
  
  
  CONCLUSIONS
  In a retrospective cohort trial, EUS-FNA was found to be highly accurate and safe in diagnosing patients with suspected pancreatic cancer, even in the presence of a plastic or metallic biliary stent. The presence of a stent did not contribute to a higher false-positive cytology rate.
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Thomas Jefferson University Hospital, Philadelphia, PA, USA. ali.siddiqui@jefferson.edu
authors.forename: Ali A
authors.initials: AA
authors.lastname: Siddiqui
authors.forename: Michael
authors.initials: M
authors.lastname: Fein
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Kowalski
authors.forename: David E
authors.initials: DE
authors.lastname: Loren
authors.forename: Mohamad A
authors.initials: MA
authors.lastname: Eloubeidi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001660:Biliary Tract Diseases; D044963:Biopsy, Fine-Needle; D016145:Endoscopy, Digestive System; D005260:Female; D006801:Humans; D008297:Male; D008670:Metals; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000175:diagnosis*; D010969:Plastics; D012189:Retrospective Studies; D015607:Stents / Q000145:classification*; D018084:Ultrasonography, Interventional
chemical_list: D008670:Metals; D010969:Plastics