Operator-controlled Imaging Significantly Reduces Radiation Exposure during EVAR

St George's Vascular Institute, 4th Floor, St James Wing, St George's Healthcare NHS Trust, Blackshaw Road, London SW17 0QT, UK. Electronic address: .
European journal of vascular and endovascular surgery: the official journal of the European Society for Vascular Surgery (Impact Factor: 2.49). 08/2012; 44(4):395-8. DOI: 10.1016/j.ejvs.2012.08.001
Source: PubMed


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.
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.
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).
Introduction of operator-controlled imaging can significantly reduce radiation exposure during EVAR, with particular reduction in the number of 'higher-dose' cases.

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Available from: Stephen Alan Black, Aug 11, 2015
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    ABSTRACT: Access to a hybrid endovascular suite is touted as a necessity for advanced endovascular aneurysm repair (EVAR) to improve imaging accuracy and safety. Yet there remain little data documenting this intuitive advantage of a hybrid setup versus a traditional operating room (OR) utilizing a portable fluoroscopic unit (C-arm) for imaging. We hypothesized that standard elective EVAR performed in a hybrid suite would improve procedural efficiency and accuracy, as well minimize patient exposure to both contrast and radiation. We retrospectively reviewed a single attending surgeon's EVAR practice, which encompassed the transition to a hybrid endovascular suite (opened July 2010). Only consecutive abdominal aneurysms were included in the analysis to attempt to create a homogenous cohort. All emergent, aorto-uni-iliac (AUI), snorkel, fenestrated, or hybrid procedures were excluded. Standard variables evaluated and compared between the two study subgroups included fluoroscopy time, operative time, contrast use, stent-graft component utilization, complication rates, and short-term endoleaks. From January 2008 to August 2012, we performed 213 EVAR procedures for abdominal aortic aneurysms. After excluding emergent, AUI, snorkel, or hybrid procedures, we analyzed 109 routine EVARs. Fifty-eight consecutive cases were done in the OR with a C-arm until July 2010, and the last 51 cases were done in the hybrid room. Both groups were well matched in terms of demographics, aneurysm morphology, and procedural characteristics. No difference was found in terms of complication rates or operative mortality, although there was a trend towards decreased fluoroscopy time, type I/III endoleaks, and a number of additional endograft components utilized. Compared with patients repaired in the OR/C-arm, EVAR done in the hybrid room resulted in less total OR time and contrast usage (p < .05). Routine EVAR performed in a hybrid fixed-imaging suite affords greater efficiency and less harmful exposure of contrast and possible radiation to the patient. Accurate imaging quality and deployment is associated with less need for additional endograft components, which should lead to improved cost efficiency. Confirmation of these findings might be necessary in a randomized control trial to fully justify the capital expenditure necessary for hybrid endovascular suites.
    European journal of vascular and endovascular surgery: the official journal of the European Society for Vascular Surgery 10/2013; 46(6). DOI:10.1016/j.ejvs.2013.09.023 · 2.49 Impact Factor
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    ABSTRACT: Objective To evaluate exposure to radiation during endovascular aneurysm repair (EVAR) performed with intraoperative guidance by preoperative computed tomographic angiogram fusion. Methods All consecutive patients who underwent standard bifurcated (BIF) or thoracic (THO), and complex fenestrated (FEN) or branched (BR) EVAR were prospectively enrolled. Indirect dose–area product (DAP), fluoroscopy time (FT), and contrast medium volume were recorded. These data were compared with a previously published prospective EVAR cohort of 301 patients and to other literature. Direct DAP and peak skin dose were measured with radiochromic films. Results are expressed as median (interquartile range). Results From December 2012 to July 2013, 102 patients underwent standard (56.8%) or complex (43.2%) EVAR. The indirect DAP (Gy.cm2) was as follows: BIF 12.2 (8.7–19.9); THO 26.0 (11.9–34.9); FEN 43.7 (24.7–57.5); and BR 47.4 (37.2–108.2). The FT (min) was as follows: BIF 10.6 (9.1–14.7); THO 8.9 (6.0–10.5); FEN 30.7 (20.2–40.5); and BR 39.5 (34.8–51.6). The contrast medium volume (mL) was as follows: BIF 59.0 (50.0–75.0); THO 80.0 (50.0–100.0); FEN 105.0 (70.0–136.0); and BR 120.0 (100.0–170.0). When compared with a previous cohort, there was a significant reduction in DAP during BIF, FEN, and BR procedures, and a significant reduction of iodinated contrast volume during FEN and BR procedures. There was also a significant reduction in DAP during BIF procedures when compared with the literature (p < .01). DAP measurement on radiochromic films was strongly correlated with indirect DAP values (r2 = .93). Conclusion The exposure of patients and operators to radiation is significantly reduced by routine use of image fusion during standard and complex EVAR.
    European Journal of Vascular and Endovascular Surgery 10/2014; 48(4). DOI:10.1016/j.ejvs.2014.05.026 · 2.49 Impact Factor
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    ABSTRACT: Context Endovascular procedures, requiring X-ray guidance, are commonly performed in vascular surgery. X-ray exposure is associated with biological risks for both patients and physicians. Medical X-ray use must follow "as low as reasonably achievable" (ALARA) principles, which aim at using the lowest radiation exposure to achieve a procedure safely. This is underlined by European and international recommendations that also suggest that adequate theoretical and practical training is mandatory during the initial education of physicians. However, the content of this education and professional practices vary widely from one country to another. Objective This review aims to summarize the basic knowledge required for vascular surgeons on X-ray physics and image production. Methods A panel of endovascular therapists (vascular surgeons and radiologists) and physicists dedicated to X-rays was gathered. International recommendations were summarized. A literature review was performed via MEDLINE to identify studies reporting dosages of common endovascular procedures. Results The different mechanisms inducing biological risks, and the associated potential effects on health, are described. Details on dose metrics are provided and a common nomenclature to measure, estimate, and report dose is proposed in order to perform accurate comparisons between publications and practices. Key points of the European and international legislation regarding medical X-ray use are summarized, and radiation protection basics for patients and staff, are detailed. Finally, a literature review is proposed for physicians to evaluate their practice. Conclusions Today's trainees will be highly exposed to radiation throughout their practice. It is thus compulsory that they undergo dedicated radiation education during their initial training, and regular refresher sessions later. In daily practice, focus on dose reduction and monitoring of patient and staff exposure are mandatory.
    European journal of vascular and endovascular surgery: the official journal of the European Society for Vascular Surgery 03/2015; 62(1). DOI:10.1016/j.ejvs.2015.01.014 · 2.49 Impact Factor