title: Occurrence of implantation metastases after resection of Klatskin tumors.
abstract: BACKGROUND
  We found a high proportion of patients with implantation metastases during follow-up after resection of a proximal cholangiocarcinoma. A remarkable fact was that all these patients had undergone preoperative endoscopic retrograde cholangiopancreatography (ERCP) with placement of a stent. ERCP is frequently used in the assessment of the proximal extension of Klatskin tumors and is usually followed by stent insertion for biliary drainage. The aim of this study was to analyze the possible risk factors leading to implantation metastases in this series of patients.
  
  
  METHODS
  Fifty-two patients who had undergone resection of a Klatskin tumor were divided into 2 groups, comparing patients who had had preoperative ERCP and stent placement (n = 41) and patients without preoperative drainage (n = 11).
  
  
  RESULTS
  Eight patients developed implantation metastases within 1 year after resection, all of whom had undergone preoperative stent placement (8/41, 20%). None of the patients without preoperative stenting developed implantation metastases. In 22 patients bile samples were taken during operation. Sixteen (72.7%) patients had malignant cells and 4 (18.2%) patients atypical cells in the bile sample. There was no difference in cytology results between the 2 groups.
  
  
  CONCLUSIONS
  This study suggests that preoperative ERCP with biliary drainage is associated with a higher frequency of implantation metastases after resection of Klatskin tumors. A properly planned prospective study, however, is needed to determine whether bile duct stenting in patients with resectable bile duct tumors is a true risk factor for the development of implantation metastases.
authors.affiliation: Department of Surgery, Academic Medical Centre, University of Amsterdam, The Netherlands.
authors.forename: H
authors.initials: H
authors.lastname: ten Hoopen-Neumann
authors.forename: M F
authors.initials: MF
authors.lastname: Gerhards
authors.forename: T M
authors.initials: TM
authors.lastname: van Gulik
authors.forename: A
authors.initials: A
authors.lastname: Bosma
authors.forename: P C
authors.initials: PC
authors.lastname: Verbeek
authors.forename: D J
authors.initials: DJ
authors.lastname: Gouma
mesh_terms: D001650:Bile Duct Neoplasms / Q000401:mortality / Q000601:surgery*; D016022:Case-Control Studies; D002760:Cholangiopancreatography, Endoscopic Retrograde / Q000009:adverse effects; D005260:Female; D006500:Hepatic Duct, Common; D006801:Humans; D018285:Klatskin Tumor / Q000401:mortality / Q000556:secondary* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D015607:Stents / Q000009:adverse effects