title: Surveillance after EVAR based on duplex ultrasound and abdominal radiography.
abstract: BACKGROUND
  Computed tomography angiography (CTA) is considered the gold standard imaging technique for surveillance following endovascular aneurysm repair (EVAR). Limitations of CTA include cost, risk of contrast nephropathy and radiation exposure. A modified surveillance protocol involving annual duplex ultrasound (DUS) and abdominal radiography (AXR) was introduced, with CTA performed only if abnormalities were identified or DUS was undiagnostic.
  
  
  METHODS
  Prospective records were maintained on patients undergoing infra-renal EVAR at a UK, tertiary referral centre. All patients enrolled with at least one-year follow-up were reviewed. Primary outcomes identified were aneurysm rupture and aneurysm-related complications. Secondary outcomes included number of CTAs avoided and cost.
  
  
  RESULTS
  Median follow-up was 36 months (range 12-57) for 194 patients. The total number of sets of surveillance imaging was 412 of which 70 (17%) required CTA. Abnormalities were found in 30 patients, 18 confirmed by CTA. Eleven patients required secondary intervention, three initially identified by AXR, three by DUS, three by both DUS and AXR, and two by CTA following undiagnostic DUS. No patient presented with rupture or aneurysm-related complications not identified by modified surveillance. Mean annual savings were €223.
  
  
  CONCLUSIONS
  EVAR surveillance based on DUS and AXR is feasible and safe. The complimentary nature of AXR and DUS is demonstrated.
authors.affiliation: Regional Vascular Unit, Royal Liverpool University Hospital, Prescot Street, Liverpool L7 8XP, UK. garethjamesharrison@yahoo.co.uk
authors.forename: G J
authors.initials: GJ
authors.lastname: Harrison
authors.forename: O A
authors.initials: OA
authors.lastname: Oshin
authors.forename: S R
authors.initials: SR
authors.lastname: Vallabhaneni
authors.forename: J A
authors.initials: JA
authors.lastname: Brennan
authors.forename: R K
authors.initials: RK
authors.lastname: Fisher
authors.forename: R G
authors.initials: RG
authors.lastname: McWilliams
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001014:Aortic Aneurysm / Q000175:diagnosis / Q000191:economics / Q000601:surgery*; D001027:Aortography / Q000009:adverse effects / Q000191:economics / Q000379:methods*; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects / Q000191:economics; D017046:Cost Savings; D003362:Cost-Benefit Analysis; D057510:Endovascular Procedures / Q000009:adverse effects / Q000191:economics; D004739:England; D005260:Female; D017721:Hospital Costs; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011182:Postoperative Care; D011183:Postoperative Complications / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000191:economics / Q000628:therapy; D011237:Predictive Value of Tests; D011829:Radiation Dosage; D012086:Reoperation; D012189:Retrospective Studies; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000009:adverse effects / Q000191:economics; D016896:Treatment Outcome; D018616:Ultrasonography, Doppler, Duplex / Q000191:economics; D019564:Unnecessary Procedures / Q000191:economics