title: Migration of retrievable expandable metallic stents inserted for malignant esophageal strictures: incidence, management, and prognostic factors in 332 patients.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the incidence, prognostic factors, and secondary management of stent migration in patients with malignant esophageal strictures.
  
  
  METHODS
  A retrospective study was performed in a single tertiary referral university hospital to identify the incidence, management, and prognostic factors for stent migration in 332 consecutive patients with placement of a retrievable expandable metallic stent. Stent migration was classified into four patterns as locations of a migrated stent: pattern I, partially migrated in the proximal direction; pattern II, partially migrated in the distal direction; pattern III, completely migrated into the stomach; and pattern IV, completely migrated into the bowel.
  
  
  RESULTS
  Stent migration occurred in 42 (12.6%) of 332 patients. Migration was partial (n = 21) or complete (n = 21), and nine (21%), 12 (29%), 11 (26%), and 10 (24%) patients had patterns I, II, III, and IV, respectively. Multivariate analysis identified the following prognostic factors: esophagogastric junction strictures caused by cancer of the gastric cardia (odds ratio 1.330; p = 0.004), patients who underwent anticancer treatment after stent placement (17.514; p < 0.001), and patients with a longer survival time (1.994; p < 0.001). Secondary management was needed for 33 of 42 patients. The strictures in the remaining nine patients improved throughout follow-up.
  
  
  CONCLUSIONS
  Stent migration occurs most commonly in patients with cancer of the gastric cardia, patients with longer survival time, and those who underwent anticancer treatment after stent placement. Stent migration is successfully managed by further intervention. Accurate knowledge of the pattern of stent migration is important for successful management.
authors.affiliation: 1 Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap 2-dong, Songpa-gu, Seoul, 138-736, Republic of Korea.
authors.forename: Jung-Hoon
authors.initials: JH
authors.lastname: Park
authors.forename: Ho-Young
authors.initials: HY
authors.lastname: Song
authors.forename: Ji Hoon
authors.initials: JH
authors.lastname: Shin
authors.forename: Young Chul
authors.initials: YC
authors.lastname: Cho
authors.forename: Jin Hyoung
authors.initials: JH
authors.lastname: Kim
authors.forename: Soo Hwan
authors.initials: SH
authors.lastname: Kim
authors.forename: Jihong
authors.initials: J
authors.lastname: Park
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D020878:Device Removal; D004938:Esophageal Neoplasms / Q000150:complications*; D004940:Esophageal Stenosis / Q000209:etiology / Q000628:therapy*; D005548:Foreign-Body Migration / Q000145:classification / Q000453:epidemiology / Q000628:therapy*; D006801:Humans; D015994:Incidence; D008670:Metals; D008875:Middle Aged; D011379:Prognosis; D015641:Radiography, Interventional; D012189:Retrospective Studies; D015607:Stents / Q000009:adverse effects*
chemical_list: D008670:Metals
keywords: dysphagia; esophageal stenosis; migration; stents