title: Operator-controlled imaging significantly reduces radiation exposure during EVAR.
abstract: BACKGROUND
  Adoption of endovascular aneurysm repair (EVAR) has led to significant reductions in the short-term morbidity and mortality associated with abdominal aortic aneurysm (AAA) repair. However, EVAR may expose both patient and interventionalist to potentially harmful levels of radiation, particularly as more complex procedures are undertaken. The aim of this study was to assess whether changing from radiographer-controlled imaging to a system of operator-controlled imaging (OCI) would influence radiation exposure, screening time or contrast dose during EVAR.
  
  
  METHODS
  Retrospective analysis identified patients that had undergone elective EVAR for infra-renal AAA before or after the change to operator-controlled imaging. Data were collected for radiation dose (measured as dose area product; DAP), screening time, total delivered contrast volume and operative duration. Data were also collected for maximum aneurysm diameter, patient age, gender and body mass index.
  
  
  RESULTS
  122 patients underwent EVAR for infra-renal AAA at a single centre between January 2011 and December 2011. 57 of these were prior to installation of OCI and 65 after installation. Median DAP was significantly lower after installation of OCI (4.9 mGy m(2); range 1.25-13.3) than it had been before installation (6.9 mGy m(2); range 1.91-95.0) (p = 0.005). Median screening times before and after installation of OCI were 20.0 min and 16.2 min respectively (p = 0.027) and median contrast volumes before and after the change to OCI were 100 ml and 90 ml respectively (p = 0.21).
  
  
  CONCLUSIONS
  Introduction of operator-controlled imaging can significantly reduce radiation exposure during EVAR, with particular reduction in the number of 'higher-dose' cases.
authors.affiliation: St George's Vascular Institute, 4th Floor, St James Wing, St George's Healthcare NHS Trust, Blackshaw Road, London SW17 0QT, UK. gpeach@doctors.org.uk
authors.forename: G
authors.initials: G
authors.lastname: Peach
authors.forename: S
authors.initials: S
authors.lastname: Sinha
authors.forename: S A
authors.initials: SA
authors.lastname: Black
authors.forename: R A
authors.initials: RA
authors.lastname: Morgan
authors.forename: I M
authors.initials: IM
authors.lastname: Loftus
authors.forename: M M
authors.initials: MM
authors.lastname: Thompson
authors.forename: R J
authors.initials: RJ
authors.lastname: Hinchliffe
mesh_terms: D000368:Aged; D000792:Angiography / Q000009:adverse effects / Q000379:methods*; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging* / Q000601:surgery; D001807:Blood Vessel Prosthesis; D057510:Endovascular Procedures / Q000379:methods*; D005260:Female; D005471:Fluoroscopy / Q000009:adverse effects / Q000379:methods*; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D015641:Radiography, Interventional / Q000009:adverse effects / Q000379:methods*; D012189:Retrospective Studies; D018570:Risk Assessment; D015607:Stents; D013997:Time Factors; D016896:Treatment Outcome; D006113:United Kingdom / Q000453:epidemiology