title: Stent Compression in Iliac Vein Compression Syndrome Associated with Acute Ilio-Femoral Deep Vein Thrombosis.
abstract: OBJECTIVE
  This study was conducted to evaluate stent compression in iliac vein compression syndrome (IVCS) and to identify its association with stent patency.
  
  
  METHODS
  Between May 2005 and June 2014, after stent placement for the treatment of IVCS with acute ilio-femoral deep vein thrombosis, follow-up CT venography was performed in 48 patients (35 women, 13 men; age range 23-87 years; median age 56 years). Using follow-up CT venography, the degree of the stent compression was calculated and used to divide patients into two groups. Possible factors associated with stent compression and patency were evaluated. The cumulative degree of stent compression and patency rate were analyzed.
  
  
  RESULTS
  All of the stents used were laser-cut nitinol stents. The proportion of limbs showing significant stent compression was 33%. Fifty-six percent of limbs in the significant stent compression group developed stent occlusion. On the other hand, only 9% of limbs in the insignificant stent compression group developed stent occlusion. Significant stent compression was inversely correlated with stent patency (p < 0.001). The median patency period evaluated with Kaplan-Meier analysis was 20.0 months for patients with significant stent compression. Other factors including gender, age, and type of stent were not correlated with stent patency. Significant stent compression occurred most frequently (87.5%) at the upper end of the stent (ilio-caval junction).
  
  
  CONCLUSIONS
  Significant compression of nitinol stents placed in IVCS highly affects stent patency. Therefore, in order to prevent stent compression in IVCS, nitinol stents with higher radial resistive force may be required.
authors.affiliation: Department of Radiology, Ajou University School of Medicine, Suwon 443-380, Korea.
authors.forename: Hun
authors.initials: H
authors.lastname: Cho
authors.affiliation: Department of Radiology, Ajou University School of Medicine, Suwon 443-380, Korea.
authors.forename: Jin Woo
authors.initials: JW
authors.lastname: Kim
authors.affiliation: Department of Thoracic & Cardiovascular Surgery, Ajou University School of Medicine, Suwon 443-380, Korea.
authors.forename: You Sun
authors.initials: YS
authors.lastname: Hong
authors.affiliation: Department of Thoracic & Cardiovascular Surgery, Ajou University School of Medicine, Suwon 443-380, Korea.
authors.forename: Sang Hyun
authors.initials: SH
authors.lastname: Lim
authors.affiliation: Department of Radiology, Ajou University School of Medicine, Suwon 443-380, Korea.
authors.forename: Je Hwan
authors.initials: JH
authors.lastname: Won
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007084:Iliac Vein / Q000000981:diagnostic imaging* / Q000473:pathology; D053208:Kaplan-Meier Estimate; D008297:Male; D062108:May-Thurner Syndrome / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000628:therapy*; D008875:Middle Aged; D010690:Phlebography; D012189:Retrospective Studies; D015607:Stents / Q000009:adverse effects; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D014654:Vascular Patency / Q000502:physiology*; D020246:Venous Thrombosis / Q000000981:diagnostic imaging / Q000628:therapy*; D055815:Young Adult
keywords: Iliac vein compression syndrome; Stent; Stent compression; Stent occlusion