title: Defining a role for contrast-enhanced ultrasound in endovascular aneurysm repair surveillance.
abstract: OBJECTIVE
  Endovascular aneurysm repair (EVAR) surveillance includes duplex ultrasound, abdominal radiography, and computed tomography angiography. Contrast-enhanced ultrasound (CEUS) has emerged as an additional modality whose role remains undefined. We evaluated whether a potential role for CEUS was the elucidation of unresolved issues following standard surveillance modalities.
  
  
  METHODS
  All patients undergoing EVAR at a tertiary referral center had surveillance based on plain abdominal radiograph and duplex ultrasound, with single arterial phase computed tomography angiography reserved for abnormalities or nondiagnostic imaging. In this prospective evaluation, from April 2010 to July 2011, discordance between imaging modalities or unresolved surveillance issues prompted CEUS. Cases and imaging were discussed in a multidisciplinary setting and outcomes recorded.
  
  
  RESULTS
  During the study period, 539 patients underwent EVAR surveillance, of whom 33 (6%) had CEUS for unresolved issues (median age, 79; range, 66-90; 28 male). Median follow-up after EVAR was 23 months (range, 0-132). In all cases, CEUS was able to resolve the clinical issue, resulting in secondary intervention in 10 patients (30%). The remaining patients were returned to surveillance. Within the cohort of 33 patients, the clinical issues were categorized into three groups. Group 1: Endoleak of uncertain classification (n = 27: 21 type II, four type I, two had endoleak excluded). Group 2: Significant aneurysm expansion (≥ 5 mm) without apparent endoleak (n = 4: one type II, three had endoleak excluded). Group 3: Target vessel patency following fenestrated EVAR (n = 2: patency confirmed in both).
  
  
  CONCLUSIONS
  CEUS can enhance EVAR surveillance through clarification of endoleak and target vessel patency when standard imaging modalities are not diagnostic.
authors.affiliation: Liverpool Vascular and Endovacular Service (LiVES), Royal Liverpool University Hospital, Liverpool, United Kingdom. alimillen@doctors.org.uk
authors.forename: Alistair
authors.initials: A
authors.lastname: Millen
authors.forename: Rana
authors.initials: R
authors.lastname: Canavati
authors.forename: Gareth
authors.initials: G
authors.lastname: Harrison
authors.forename: Richard G
authors.initials: RG
authors.lastname: McWilliams
authors.forename: Steve
authors.initials: S
authors.lastname: Wallace
authors.forename: Srinivasa R
authors.initials: SR
authors.lastname: Vallabhaneni
authors.forename: Robert K
authors.initials: RK
authors.lastname: Fisher
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging / Q000601:surgery*; D001027:Aortography / Q000379:methods; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects; D003287:Contrast Media; D057867:Endoleak / Q000000981:diagnostic imaging* / Q000209:etiology / Q000628:therapy; D057510:Endovascular Procedures / Q000009:adverse effects; D005260:Female; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging* / Q000209:etiology / Q000628:therapy; D006801:Humans; D008297:Male; D010743:Phospholipids; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013459:Sulfur Hexafluoride; D062606:Tertiary Care Centers; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D018616:Ultrasonography, Doppler, Duplex; D014654:Vascular Patency
chemical_list: D003287:Contrast Media; D010743:Phospholipids; C420843:contrast agent BR1; D013459:Sulfur Hexafluoride