Audit of radiation doses during endovascular aneurysm repair

Audit of radiation doses during endovascular aneurysm repair | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Audit of radiation doses during endovascular aneurysm repair Michael Threader, Rebecca Sketcher, Sapna Puppala This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8555129/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Purpose A common intervention for abdominal aortic aneurysm is endovascular aneurysm repair using x-ray guided fluoroscopy. Ionising radiation carries stochastic and deterministic health risks to patients. Therefore, it is beneficial to monitor radiation doses in endovascular aneurysm repair. This project aims to compare radiation doses for endovascular aneurysm repairs performed in 2014 and in 2021 at the Leeds Teaching Hospitals Trust. Trends in screening times, and the effect of operator number on radiation dose and screening time were also investigated. Materials & methods 60 cases in 2014 and 44 cases in 2021 were included. Median radiation doses and screening times in 2014 and 2021 were calculated and analysed. The effect of operator number on screening times and radiation doses was also analysed. Results Median radiation dose was 46.45% higher in 2021 than in 2014. In 2014, median radiation dose was lower with two operators instead of one; in 2021 operator number had no significant effect on radiation dose. Median screening time was 29% longer in 2014. In 2021 screening times were found to increase with operator number, and procedures performed with four operators had the longest screening times in 2021. Conclusion Radiation doses in endovascular aneurysm repair have increased in 2021 from 2014 and may be the result of ageing equipment. Operator number influenced radiation doses and screening time in some instances and may be an area for further research with possible implications into procedure protocol for endovascular aneurysm repair. EVAR AAA Endovascular aneurysm repair Abdominal aortic aneurysm Interventional radiology Radiation Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Males aged over 65 years are eligible for screening for abdominal aortic aneurysm (AAA) in the United Kingdom (UK). The screening programme identifies a 1.34% prevalence of AAA in England. There are 3000 deaths a year from AAA rupture, accounting for 1.7% of all deaths of men over 65 years [ 1 ]. These figures highlight the importance of offering safe interventions to prevent AAA rupture. Prevention of AAA rupture involves screening and monitoring. AAAs identified by abdominal ultrasound ≥ 5.5cm qualify for intervention [ 2 ]. Options for intervention include endovascular aneurysm repair (EVAR) or open surgical repair, and both demonstrate similar survival rates [ 3 ]. Open repair is typically offered for patients whose anaesthetic risk is lower, with fewer comorbidities or with more suitable abdominal anatomy [ 2 ]. Given the strong association of AAA with other co-morbidities such as smoking and hypertension [ 4 ], it is such that many patients are ineligible for open aneurysm repair. Therefore, EVAR is a primary choice of intervention for AAA [ 5 ]. While an effective intervention to prevent rupture of AAA, EVAR carries some risks to the patient from ionising radiation. These can be broadly categorised as stochastic and deterministic effects of radiation [ 6 ]. Deterministic effects include immediate effects of exposure to radiation which can manifest as radiation-related injuries such as skin burns and radiation sickness. Stochastic effects describe longer-term consequences, including increased risk of developing malignancy from DNA mutations [ 7 ]. Given the risks associated with the use of radiation in medical procedures, it is beneficial to review trends in radiation doses patients receive to maintain patient safety. This project therefore poses the question: “For patients that have undergone endovascular aneurysm repair at Leeds Teaching Hospitals Trust (LTHT), have radiation doses increased in 2021 compared to 2014?” The primary aim of the project of the project is to audit whether radiation doses have increased for patients receiving EVAR in 2021 compared with 2014 at LTHT. Secondary objectives are to identify the effect of operator number on screening time and on radiation doses in 2014 and 2021 [ 8 ]. Materials & methods This is a retrospective audit of radiation doses in 2014 and in 2021. Radiation doses collected in 2014 were used as standard for comparison. This study design allows objective comparison of radiation doses to assess whether they have increased from 2014 in 2021. Data for 2014 was collected using the Computerised Radiology Information System (CRIS) database. This was filtered to show all EVAR procedures performed in 2014 at LTHT. For each procedure, sex of the patient, age at the time of procedure, procedure start and finish times, fluoroscopy screening time, contrast and contrast volume used, screening time in minutes, radiation dose in cGy, procedure complexity and number of operators were recorded. This data was then transferred to a Microsoft Excel spreadsheet and anonymised using National Health Service (NHS) number as the identifier. These variables were also obtained for EVAR procedures performed at LTHT in 2021 from the 2024 National RadEVAIR Survey [ 9 ]. Further data collection was performed using the CRIS system for 2021 to obtain operator numbers for each procedure collected. Inclusion criteria for this project were all patients who underwent EVAR procedures in 2014 and in 2021 at LTHT. Exclusion criteria included thoracic EVAR (TEVAR) procedures, branched EVAR (BREVAR) procedures, fenestrated EVAR (FEVAR) procedures, as these produced too wide a variation of radiation doses for comparison with standard EVAR procedures. Cases with missing data (such as radiation dose) or where it was not a patient’s first EVAR procedure were also excluded. Of the 78 EVAR procedures recorded in 2021, 44 met these criteria and were included in the project. Four cases were removed from the 2014 dataset using the same criteria. Descriptive analysis was performed on the data collected, including summary of the demographic information of the patients involved. Statistical analysis was performed to determine the distribution of the data, and to test the statistical significance of any findings elicited from descriptive analysis. Results Study population 44 EVARs performed in 2021, and 60 performed in 2014 were included in the study. The mean age of patients in 2021 was 77.3 years (± 6.88 SD). The mean age of patients in 2014 was 77.97 years (± 7.82 SD). 84.09% of patients in 2021, and 90% of patients in 2014 were male. Radiation doses Median radiation dose for EVAR in 2014 was 10715cGy with an interquartile range of 9189.75cGy Median radiation dose for EVAR procedures in 2021 was 15692.5cGy and the interquartile range was 21036.98cGy. There were two outliers in 2021 with doses of 838383cGy and 252944cGy. 2014 versus 2021 radiation doses Shapiro-Wilk test assessed distribution of the data collected for 2021. For radiation doses, the W value = 0.265 and p = 1.58x10-13. Therefore, the Shapiro-Wilk test results were statistically significant, showing that radiation doses recorded in 2021 were not normally distributed. Median radiation dose was 46.45% higher in 2021 than in 2014. Mann-Whitney-U test showed W = 970 and p = 0.0215, showing a statistically significant increase in median radiation dose from 2014 to 2021 (Fig. 1 ). Radiation dose by operator number The modal operator number was two operators in 2021 and one operator in 2014. Median radiation doses by operator number are summarised in Fig. 2 . There was a 43.08% increase in median radiation dose with two operators compared with one operator in 2014 (Fig. 3 ). Mann-Whitney-U test showed a statistically significant increase in median radiation dose with one operator compared with two operators in 2014. There was no significant effect on median radiation dose with any other combination of operator numbers in 2014. Mann-Whitney U test found no statistically significant effect of operator number on median radiation dose in 2021. Screening times 2014 Median screening time for EVAR procedures in 2014 was 19.21 with an interquartile range of 12.195 minutes 2021 Median screening time for EVAR procedures in 2021 was 24.79 minutes with an interquartile range of 17.33 minutes. 2014 vs 2021 Man-Whitney U test showed a significant increase in screening time in 2021 compared with 2014 (U = 949.5, p = 0.015). These findings are summarised in Fig. 4 . Screening time and operator number Mann-Whitney U test showed that operator number had no significant effect on screening times in 2014. In 2021, The median screening time for 4 operators was 64.18% longer than the median screening time for 2 operators. Mann-Whitney U test found this to be a significant increase in screening time (U = 7.0, p = 0.031) (Fig. 5 ). Discussion Most cases included in the audit involved male patients (90% in 2014, 84.09% in 2021). This is likely reflective of AAA being three times more prevalent in males than females in the UK [ 10 ]. This may support the current eligibility criteria for the NHS AAA screening programme which includes only males [ 1 ]. Alternatively, it is possible that many male cases were included from AAA being identified through the screening programme leading to predominantly male cases. There is evidence that female patients suffer worse post-operative outcomes following EVAR, therefore AAAs identified in female patients may not be suitable for intervention [ 11 ]. Fewer EVAR procedures were recorded in 2021 than in 2014. A reason for this may be that more AAAs were managed by open repair in 2021 than in 2014. Following the emergence of EVAR, The National Institute for Health and Care Excellence (NICE) offered it as a primary intervention for AAA in their 2009 guidelines for the management of AAA [ 12 ]. Following the 2020 NICE guidelines, open repair was reinforced as a suitable management option for eligible patients with AAA [ 1 , 13 ]. After 2009, EVAR procedures for AAA rose from 54% to 66% in 2013. Meanwhile, between 2019 and 2020, more than half of the interventional procedures for AAA in England were open repairs [ 14 ]. This audit showed radiation doses during EVAR significantly increased from 2014 to 2021. Ionising radiation used in EVAR has been shown to cause deterministic effects, such as injury to skin, and stochastic effects, including malignancy [ 7 ]. There is evidence that EVAR programmes, when including pre-operative and post-operative computerised tomography (CT) imaging, causes a 0.42% risk of malignancy in patients aged 70 years [ 15 ]. If radiation doses have increased since 2014, long-term health risks may also have increased. While higher median radiation doses confer a greater risk of malignancy in the general population, the mean age of patients in 2021 was 77.3 years (± 6.88 SD). Evidence suggests that lifetime risk of malignancy from radiation exposure reduces with age [ 16 ]. Therefore, while risks from radiation should be considered in risk-benefit decision-making, the average patient undergoing EVAR may have a lower long-term health risk than the general population. The overall increase in median radiation dose found in 2021 from 2014 prompts further investigation for the cause of this. There is evidence to suggest that as radiology equipment ages, radiation dose also increases due to reduced output over time requiring higher exposure [ 17 ]. This may be true for the cases included in this study, as the x-ray machine used for the recorded EVARs was relatively new in 2014 and had aged by 2021. It would be of benefit to assess further parameters of radiological equipment at LTHT to analyse their overall efficiency and how this relates to radiation doses. The European Society of Radiology promotes ‘Golden Rules’, stating that at least 60% of radiological equipment should be less than five years old, no more than 30% be between six to ten years old, and no more than 10% over ten years old [ 18 ]. These guidelines are recommended for economical and departmental efficiency. For example, older equipment will require more repair, with less spare parts readily available. Additionally, more frequent faults in the equipment may delay patient treatment and diagnosis [ 19 ]. Literature also suggests that older models deliver higher radiation doses than modern x-ray models [ 20 ]. Regular replacement of x-ray machines therefore provides incrementally lower radiation doses as newer equipment is used over time [ 18 , 19 ]. Possible areas for further research include a meta-analysis of median radiation doses from the same x-ray machines across healthcare trusts to observe how median radiation doses change as the x-ray machine ages. In 2014, having two operators significantly reduced median radiation doses compared to a single operator. Extra assistance during the procedure may increase speed and efficiency. In 2021, no significant effect of operator number on radiation dose was observed. A cause for this may be that the observed overall increase in median radiation doses (possibly from ageing equipment) led to a loss in the previous benefit of having multiple operators by 2021. In 2021 EVAR procedures with four operators had higher median screening times. Clinical notes for cases requiring four operators were not reviewed during data collection, but it is possible that four operators were due to multiple procedures taking place simultaneously. With multiple procedures, more X-ray acquisitions cause a longer screening time [ 21 ]. Median screening time increased from 2014 to 2021, as well as an increase with four operators in 2021. The increase from 2014 to 2021 may also be explained by ageing equipment, but this should be explored more closely to establish the true causation. Other factors have been shown to affect screening times during EVAR, including age, anatomy, hypertension, and dyslipidaemia [ 22 ]. Analysis of age and screening time could be an area for further investigation and comparison to other literature. This project was limited in that staff radiation exposure levels were not collected for the EVAR procedures. Many radiology staff wear dosimeters which could be collected to measure staff exposure during EVAR cases included in this project [ 23 ]. Other studies found staff positioning to be a major influencer on radiation exposure during EVAR, and have placed further dosimeters on the head, hands, and legs of operating staff [ 24 ]. These methods could be replicated to further investigate the overall safety of EVAR for patients and staff. Another limitation of this study was that patient metrics including BMI were not collected. BMI has been discussed as a significant factor effecting an individual patient’s radiation dose in EVAR [ 25 , 26 ]. At present, this project cannot exclude the possibility that BMI had a significant effect on the change in radiation dose observed from 2014 to 2021. Finally, data was only collected for 2014 and 2021. If data had been collected for all years between 2014 and 2021, it may better allow for observation of trends in radiation doses. This may allow for better explanation and analysis of the observed increase in radiation dose in this audit. Summary and conclusions An increase in median radiation dose during EVARs at LTHT was observed in 2021 compared with 2014. This may be a result of ageing equipment, and further analysis of equipment efficiency over time may help assess this link. The effect of operator number on radiation dose and screening time is an emerging area of interest which may be further explored to allow for recommendations on the safest numbers of operators for EVARs. Declarations Ethical approval and consent to participate: not applicable Consent for publication : not applicable Availability of data and material : available upon request Competing interests : no conflicts of interest Funding : this study received no funding Author’s contributions : Dr M Threader: primary author, data collection, data presentation, interprofessional communications Dr R Sketcher: project co-author, data collection, data presentation, interprofessional communications, data analysis Dr S Puppala: overall supervision, feedback, design and aims, dataset provision Acknowledgements University of Leeds Dr R Frood References National Institute for Health and Care Excellence. Abdominal aortic aneurysm: screening (2020) NICE Guideline 156 National Institute for Health and Care Excellence. Abdominal aortic aneurysm: diagnosis and management (2020) NICE Guideline 156 Blankensteijn JD, De Jong SE, Prinssen M, Van Der Ham AC, Buth J, Van Sterkenburg SM, Verhagen HJ, Buskens E, Grobbee DE (2005) Two-year outcomes after conventional or endovascular repair of abdominal aortic aneurysms. N Engl J Med 352(23):2398–2405 Howard DP, Banerjee A, Fairhead JF, Handa A, Silver LE, Rothwell PM (2015) Age-specific incidence, risk factors and outcome of acute abdominal aortic aneurysms in a defined population. J Br Surg 102(8):907–915 Suckow BD, Goodney PP, Columbo JA, Kang R, Stone DH, Sedrakyan A, Cronenwett JL, Fillinger MF (2018) National trends in open surgical, endovascular, and branched-fenestrated endovascular aortic aneurysm repair in Medicare patients. J Vasc Surg 67(6):1690–1697 Hamada N, Fujimichi Y (2014) Classification of radiation effects for dose limitation purposes: history, current situation and future prospects. J Radiat Res 55(4):629–640 Versant Physics Deterministic vs stochastic effects: whats the difference? [Online] 2021 Apr 21. Available from: www.versantphysics.com Michael Threader (2021) Unpublished ESREP Project Protocol. University of Leeds Tsitsiou Y, Velan B, Ross R, Lakshminarayan R, Rogers A, Hamady M (2024) National UK survey of radiation doses during endovascular aortic interventions. Cardiovasc Interv Radiol 47(1):92–100 Sweeting MJ, Masconi KL, Jones E Abdominal aortic aneurysm screening for women is unlikely to be a fair use of NHS resources Lo RC, Bensley RP, Hamdan AD, Wyers M, Adams JE, Schermerhorn ML, Vascular Study Group of New England (2013) Gender differences in abdominal aortic aneurysm presentation, repair, and mortality in the Vascular Study Group of New England. J Vasc Surg 57(5):1261–1268 National Institute for Health and Care Excellence Endovascular stent grafts for the treatment of abdominal aortic aneurysm. 25 Feb 2009. Technology Appraisal Guidance 167. Dalman RL (2020) Controversy continues following final NICE guidelines update. J Vasc Surg 72(1):1–3 Public Health England Latest annual abdominal aortic aneurysm screening report published. 3 Mar 2021. [Online] PHE Screening. Available from: phescreening.blog.gov.uk White HA, Macdonald S (2010) Estimating risk associated with radiation exposure during follow-up after endovascular aortic repair (EVAR). J Cardiovasc Surg 51(1):95 Power SP, Moloney F, Twomey M, James K, O’Connor OJ, Maher MM (2016) Computed tomography and patient risk: Facts, perceptions and uncertainties. World J Radiol 8(12):902 Nemati F, Mohammadi M, Gholami M (2021) A survey on exposure parameters variation due to aging in radiology devices. J Biomedical Phys Eng 11(3):407 European Coordination Committee of the Radiological (2021) Electromedical and Healthcare IT Industry. Medical Imaging Equipment Age Profile and Density European Society of Radiology (ESR) (2014) communications@ myesr. org. Renewal of radiological equipment. Insights into imaging 5:543–546 Kemerink M, Dierichs TJ, Dierichs J, Huynen HJ, Wildberger JE, van Engelshoven JM, Kemerink GJ (2011) Characteristics of a first-generation x-ray system. Radiology 259(2):534–539 Johnson DR, Kyriou J, Morton EJ, Clifton A, Fitzgerald M, Macsweeney E (2001) Radiation protection in interventional radiology. Clin Radiol 56(2):99–106 Efthymiou FO, Kakkos SK, Metaxas VI, Dimitroukas CP, Moulakakis KG, Papadoulas SI, Kouri NK, Tsimpoukis AL, Nikolakopoulos KM, Papageorgopoulou CP, Panayiotakis GS (2023) Factors influencing fluoroscopy time in endovascular treatment of abdominal aneurysms: a retrospective study. Radiat Prot Dosimetry 199(5):443–452 UK Health Security Agency Personal Dosimetry Service. [Online]. Available from: Clauss N, Kuntz S, Colvard B, Ohana M, Mertz L, Lejay A, Chakfe N (2024) Intraoperative Staff Radiation Exposure During Aortic Endovascular Procedures. Ann Vasc Surg 106:16–24 De Ruiter QM, Gijsberts CM, Hazenberg CE, Moll FL, Van Herwaarden JA (2017) Radiation awareness for endovascular abdominal aortic aneurysm repair in the hybrid operating room. An instant patient risk chart for daily practice. J Endovasc Ther 24(3):425–434 Sen I, Tenorio ER, Pitcher G, Mix D, Marcondes GB, Lima GB, Ozbek P, Oderich GS (2021) Effect of obesity on radiation exposure, quality of life scores, and outcomes of fenestrated-branched endovascular aortic repair of pararenal and thoracoabdominal aortic aneurysms. J Vasc Surg 73(4):1156–1166 Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8555129","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":593257379,"identity":"4e0d9464-8d10-4510-ac2e-817eb186ce7e","order_by":0,"name":"Michael 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the United Kingdom (UK). The screening programme identifies a 1.34% prevalence of AAA in England. There are 3000 deaths a year from AAA rupture, accounting for 1.7% of all deaths of men over 65 years [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. These figures highlight the importance of offering safe interventions to prevent AAA rupture.\u003c/p\u003e \u003cp\u003ePrevention of AAA rupture involves screening and monitoring. AAAs identified by abdominal ultrasound\u0026thinsp;\u0026ge;\u0026thinsp;5.5cm qualify for intervention [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Options for intervention include endovascular aneurysm repair (EVAR) or open surgical repair, and both demonstrate similar survival rates [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Open repair is typically offered for patients whose anaesthetic risk is lower, with fewer comorbidities or with more suitable abdominal anatomy [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Given the strong association of AAA with other co-morbidities such as smoking and hypertension [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e], it is such that many patients are ineligible for open aneurysm repair. Therefore, EVAR is a primary choice of intervention for AAA [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eWhile an effective intervention to prevent rupture of AAA, EVAR carries some risks to the patient from ionising radiation. These can be broadly categorised as stochastic and deterministic effects of radiation [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Deterministic effects include immediate effects of exposure to radiation which can manifest as radiation-related injuries such as skin burns and radiation sickness. Stochastic effects describe longer-term consequences, including increased risk of developing malignancy from DNA mutations [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eGiven the risks associated with the use of radiation in medical procedures, it is beneficial to review trends in radiation doses patients receive to maintain patient safety. This project therefore poses the question: \u0026ldquo;For patients that have undergone endovascular aneurysm repair at Leeds Teaching Hospitals Trust (LTHT), have radiation doses increased in 2021 compared to 2014?\u0026rdquo;\u003c/p\u003e \u003cp\u003eThe primary aim of the project of the project is to audit whether radiation doses have increased for patients receiving EVAR in 2021 compared with 2014 at LTHT. Secondary objectives are to identify the effect of operator number on screening time and on radiation doses in 2014 and 2021 [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e].\u003c/p\u003e"},{"header":"Materials \u0026 methods","content":"\u003cp\u003eThis is a retrospective audit of radiation doses in 2014 and in 2021. Radiation doses collected in 2014 were used as standard for comparison. This study design allows objective comparison of radiation doses to assess whether they have increased from 2014 in 2021.\u003c/p\u003e \u003cp\u003eData for 2014 was collected using the Computerised Radiology Information System (CRIS) database. This was filtered to show all EVAR procedures performed in 2014 at LTHT. For each procedure, sex of the patient, age at the time of procedure, procedure start and finish times, fluoroscopy screening time, contrast and contrast volume used, screening time in minutes, radiation dose in cGy, procedure complexity and number of operators were recorded. This data was then transferred to a Microsoft Excel spreadsheet and anonymised using National Health Service (NHS) number as the identifier. These variables were also obtained for EVAR procedures performed at LTHT in 2021 from the 2024 National RadEVAIR Survey [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Further data collection was performed using the CRIS system for 2021 to obtain operator numbers for each procedure collected.\u003c/p\u003e \u003cp\u003eInclusion criteria for this project were all patients who underwent EVAR procedures in 2014 and in 2021 at LTHT. Exclusion criteria included thoracic EVAR (TEVAR) procedures, branched EVAR (BREVAR) procedures, fenestrated EVAR (FEVAR) procedures, as these produced too wide a variation of radiation doses for comparison with standard EVAR procedures. Cases with missing data (such as radiation dose) or where it was not a patient\u0026rsquo;s first EVAR procedure were also excluded. Of the 78 EVAR procedures recorded in 2021, 44 met these criteria and were included in the project. Four cases were removed from the 2014 dataset using the same criteria.\u003c/p\u003e \u003cp\u003eDescriptive analysis was performed on the data collected, including summary of the demographic information of the patients involved. Statistical analysis was performed to determine the distribution of the data, and to test the statistical significance of any findings elicited from descriptive analysis.\u003c/p\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eStudy population\u003c/h2\u003e \u003cp\u003e44 EVARs performed in 2021, and 60 performed in 2014 were included in the study. The mean age of patients in 2021 was 77.3 years (\u0026plusmn;\u0026thinsp;6.88 SD). The mean age of patients in 2014 was 77.97 years (\u0026plusmn;\u0026thinsp;7.82 SD). 84.09% of patients in 2021, and 90% of patients in 2014 were male.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eRadiation doses\u003c/h3\u003e\n\u003cp\u003eMedian radiation dose for EVAR in 2014 was 10715cGy with an interquartile range of 9189.75cGy\u003c/p\u003e \u003cp\u003eMedian radiation dose for EVAR procedures in 2021 was 15692.5cGy and the interquartile range was 21036.98cGy. There were two outliers in 2021 with doses of 838383cGy and 252944cGy.\u003c/p\u003e \u003cp\u003e \u003cb\u003e2014 versus 2021 radiation doses\u003c/b\u003e \u003c/p\u003e \u003cp\u003eShapiro-Wilk test assessed distribution of the data collected for 2021. For radiation doses, the W value\u0026thinsp;=\u0026thinsp;0.265 and p\u0026thinsp;=\u0026thinsp;1.58x10-13. Therefore, the Shapiro-Wilk test results were statistically significant, showing that radiation doses recorded in 2021 were not normally distributed.\u003c/p\u003e \u003cp\u003eMedian radiation dose was 46.45% higher in 2021 than in 2014. Mann-Whitney-U test showed W\u0026thinsp;=\u0026thinsp;970 and p\u0026thinsp;=\u0026thinsp;0.0215, showing a statistically significant increase in median radiation dose from 2014 to 2021 (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\n\u003ch3\u003eRadiation dose by operator number\u003c/h3\u003e\n\u003cp\u003eThe modal operator number was two operators in 2021 and one operator in 2014.\u003c/p\u003e \u003cp\u003eMedian radiation doses by operator number are summarised in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. There was a 43.08% increase in median radiation dose with two operators compared with one operator in 2014 (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). Mann-Whitney-U test showed a statistically significant increase in median radiation dose with one operator compared with two operators in 2014. There was no significant effect on median radiation dose with any other combination of operator numbers in 2014.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eMann-Whitney U test found no statistically significant effect of operator number on median radiation dose in 2021.\u003c/p\u003e\n\u003ch3\u003eScreening times\u003c/h3\u003e\n\u003cp\u003e \u003cb\u003e2014\u003c/b\u003e \u003c/p\u003e \u003cp\u003eMedian screening time for EVAR procedures in 2014 was 19.21 with an interquartile range of 12.195 minutes\u003c/p\u003e \u003cp\u003e \u003cb\u003e2021\u003c/b\u003e \u003c/p\u003e \u003cp\u003eMedian screening time for EVAR procedures in 2021 was 24.79 minutes with an interquartile range of 17.33 minutes.\u003c/p\u003e \u003cp\u003e \u003cb\u003e2014 vs 2021\u003c/b\u003e \u003c/p\u003e \u003cp\u003eMan-Whitney U test showed a significant increase in screening time in 2021 compared with 2014 (U\u0026thinsp;=\u0026thinsp;949.5, p\u0026thinsp;=\u0026thinsp;0.015). These findings are summarised in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eScreening time and operator number\u003c/h2\u003e \u003cp\u003eMann-Whitney U test showed that operator number had no significant effect on screening times in 2014.\u003c/p\u003e \u003cp\u003eIn 2021, The median screening time for 4 operators was 64.18% longer than the median screening time for 2 operators. Mann-Whitney U test found this to be a significant increase in screening time (U\u0026thinsp;=\u0026thinsp;7.0, p\u0026thinsp;=\u0026thinsp;0.031) (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eMost cases included in the audit involved male patients (90% in 2014, 84.09% in 2021). This is likely reflective of AAA being three times more prevalent in males than females in the UK [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. This may support the current eligibility criteria for the NHS AAA screening programme which includes only males [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Alternatively, it is possible that many male cases were included from AAA being identified through the screening programme leading to predominantly male cases. There is evidence that female patients suffer worse post-operative outcomes following EVAR, therefore AAAs identified in female patients may not be suitable for intervention [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eFewer EVAR procedures were recorded in 2021 than in 2014. A reason for this may be that more AAAs were managed by open repair in 2021 than in 2014. Following the emergence of EVAR, The National Institute for Health and Care Excellence (NICE) offered it as a primary intervention for AAA in their 2009 guidelines for the management of AAA [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Following the 2020 NICE guidelines, open repair was reinforced as a suitable management option for eligible patients with AAA [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. After 2009, EVAR procedures for AAA rose from 54% to 66% in 2013. Meanwhile, between 2019 and 2020, more than half of the interventional procedures for AAA in England were open repairs [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThis audit showed radiation doses during EVAR significantly increased from 2014 to 2021. Ionising radiation used in EVAR has been shown to cause deterministic effects, such as injury to skin, and stochastic effects, including malignancy [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. There is evidence that EVAR programmes, when including pre-operative and post-operative computerised tomography (CT) imaging, causes a 0.42% risk of malignancy in patients aged 70 years [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. If radiation doses have increased since 2014, long-term health risks may also have increased.\u003c/p\u003e \u003cp\u003eWhile higher median radiation doses confer a greater risk of malignancy in the general population, the mean age of patients in 2021 was 77.3 years (\u0026plusmn;\u0026thinsp;6.88 SD). Evidence suggests that lifetime risk of malignancy from radiation exposure reduces with age [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Therefore, while risks from radiation should be considered in risk-benefit decision-making, the average patient undergoing EVAR may have a lower long-term health risk than the general population.\u003c/p\u003e \u003cp\u003eThe overall increase in median radiation dose found in 2021 from 2014 prompts further investigation for the cause of this. There is evidence to suggest that as radiology equipment ages, radiation dose also increases due to reduced output over time requiring higher exposure [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. This may be true for the cases included in this study, as the x-ray machine used for the recorded EVARs was relatively new in 2014 and had aged by 2021. It would be of benefit to assess further parameters of radiological equipment at LTHT to analyse their overall efficiency and how this relates to radiation doses.\u003c/p\u003e \u003cp\u003eThe European Society of Radiology promotes \u0026lsquo;Golden Rules\u0026rsquo;, stating that at least 60% of radiological equipment should be less than five years old, no more than 30% be between six to ten years old, and no more than 10% over ten years old [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. These guidelines are recommended for economical and departmental efficiency. For example, older equipment will require more repair, with less spare parts readily available. Additionally, more frequent faults in the equipment may delay patient treatment and diagnosis [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eLiterature also suggests that older models deliver higher radiation doses than modern x-ray models [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Regular replacement of x-ray machines therefore provides incrementally lower radiation doses as newer equipment is used over time [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. Possible areas for further research include a meta-analysis of median radiation doses from the same x-ray machines across healthcare trusts to observe how median radiation doses change as the x-ray machine ages.\u003c/p\u003e \u003cp\u003eIn 2014, having two operators significantly reduced median radiation doses compared to a single operator. Extra assistance during the procedure may increase speed and efficiency. In 2021, no significant effect of operator number on radiation dose was observed. A cause for this may be that the observed overall increase in median radiation doses (possibly from ageing equipment) led to a loss in the previous benefit of having multiple operators by 2021.\u003c/p\u003e \u003cp\u003eIn 2021 EVAR procedures with four operators had higher median screening times. Clinical notes for cases requiring four operators were not reviewed during data collection, but it is possible that four operators were due to multiple procedures taking place simultaneously. With multiple procedures, more X-ray acquisitions cause a longer screening time [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eMedian screening time increased from 2014 to 2021, as well as an increase with four operators in 2021. The increase from 2014 to 2021 may also be explained by ageing equipment, but this should be explored more closely to establish the true causation. Other factors have been shown to affect screening times during EVAR, including age, anatomy, hypertension, and dyslipidaemia [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Analysis of age and screening time could be an area for further investigation and comparison to other literature.\u003c/p\u003e \u003cp\u003eThis project was limited in that staff radiation exposure levels were not collected for the EVAR procedures. Many radiology staff wear dosimeters which could be collected to measure staff exposure during EVAR cases included in this project [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. Other studies found staff positioning to be a major influencer on radiation exposure during EVAR, and have placed further dosimeters on the head, hands, and legs of operating staff [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. These methods could be replicated to further investigate the overall safety of EVAR for patients and staff.\u003c/p\u003e \u003cp\u003eAnother limitation of this study was that patient metrics including BMI were not collected. BMI has been discussed as a significant factor effecting an individual patient\u0026rsquo;s radiation dose in EVAR [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. At present, this project cannot exclude the possibility that BMI had a significant effect on the change in radiation dose observed from 2014 to 2021.\u003c/p\u003e \u003cp\u003eFinally, data was only collected for 2014 and 2021. If data had been collected for all years between 2014 and 2021, it may better allow for observation of trends in radiation doses. This may allow for better explanation and analysis of the observed increase in radiation dose in this audit.\u003c/p\u003e"},{"header":"Summary and conclusions","content":"\u003cp\u003eAn increase in median radiation dose during EVARs at LTHT was observed in 2021 compared with 2014. This may be a result of ageing equipment, and further analysis of equipment efficiency over time may help assess this link. The effect of operator number on radiation dose and screening time is an emerging area of interest which may be further explored to allow for recommendations on the safest numbers of operators for EVARs.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthical approval and consent to participate:\u003c/strong\u003e not applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e: not applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and material\u003c/strong\u003e: available upon request\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e: no conflicts of interest\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e: this study received no funding\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor\u0026rsquo;s contributions\u003c/strong\u003e:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003eDr M Threader: primary author, data collection, data presentation, interprofessional communications\u003c/li\u003e\n \u003cli\u003eDr R Sketcher: project co-author, data collection, data presentation, interprofessional communications, data analysis\u003c/li\u003e\n \u003cli\u003eDr S Puppala: overall supervision, feedback, design and aims, dataset provision\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003eUniversity of Leeds\u003c/li\u003e\n \u003cli\u003eDr R Frood\u003c/li\u003e\n\u003c/ul\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eNational Institute for Health and Care Excellence. Abdominal aortic aneurysm: screening (2020) NICE Guideline 156\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNational Institute for Health and Care Excellence. Abdominal aortic aneurysm: diagnosis and management (2020) NICE Guideline 156\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBlankensteijn JD, De Jong SE, Prinssen M, Van Der Ham AC, Buth J, Van Sterkenburg SM, Verhagen HJ, Buskens E, Grobbee DE (2005) Two-year outcomes after conventional or endovascular repair of abdominal aortic aneurysms. N Engl J Med 352(23):2398\u0026ndash;2405\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHoward DP, Banerjee A, Fairhead JF, Handa A, Silver LE, Rothwell PM (2015) Age-specific incidence, risk factors and outcome of acute abdominal aortic aneurysms in a defined population. J Br Surg 102(8):907\u0026ndash;915\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSuckow BD, Goodney PP, Columbo JA, Kang R, Stone DH, Sedrakyan A, Cronenwett JL, Fillinger MF (2018) National trends in open surgical, endovascular, and branched-fenestrated endovascular aortic aneurysm repair in Medicare patients. J Vasc Surg 67(6):1690\u0026ndash;1697\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHamada N, Fujimichi Y (2014) Classification of radiation effects for dose limitation purposes: history, current situation and future prospects. J Radiat Res 55(4):629\u0026ndash;640\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVersant Physics Deterministic vs stochastic effects: whats the difference? [Online] 2021 Apr 21. Available from: www.versantphysics.com\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMichael Threader (2021) Unpublished ESREP Project Protocol. University of Leeds\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTsitsiou Y, Velan B, Ross R, Lakshminarayan R, Rogers A, Hamady M (2024) National UK survey of radiation doses during endovascular aortic interventions. Cardiovasc Interv Radiol 47(1):92\u0026ndash;100\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSweeting MJ, Masconi KL, Jones E Abdominal aortic aneurysm screening for women is unlikely to be a fair use of NHS resources\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLo RC, Bensley RP, Hamdan AD, Wyers M, Adams JE, Schermerhorn ML, Vascular Study Group of New England (2013) Gender differences in abdominal aortic aneurysm presentation, repair, and mortality in the Vascular Study Group of New England. J Vasc Surg 57(5):1261\u0026ndash;1268\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNational Institute for Health and Care Excellence Endovascular stent grafts for the treatment of abdominal aortic aneurysm. 25 Feb 2009. Technology Appraisal Guidance 167.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDalman RL (2020) Controversy continues following final NICE guidelines update. J Vasc Surg 72(1):1\u0026ndash;3\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePublic Health England Latest annual abdominal aortic aneurysm screening report published. 3 Mar 2021. [Online] PHE Screening. Available from: phescreening.blog.gov.uk\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWhite HA, Macdonald S (2010) Estimating risk associated with radiation exposure during follow-up after endovascular aortic repair (EVAR). J Cardiovasc Surg 51(1):95\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePower SP, Moloney F, Twomey M, James K, O\u0026rsquo;Connor OJ, Maher MM (2016) Computed tomography and patient risk: Facts, perceptions and uncertainties. World J Radiol 8(12):902\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNemati F, Mohammadi M, Gholami M (2021) A survey on exposure parameters variation due to aging in radiology devices. J Biomedical Phys Eng 11(3):407\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEuropean Coordination Committee of the Radiological (2021) Electromedical and Healthcare IT Industry. Medical Imaging Equipment Age Profile and Density\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEuropean Society of Radiology (ESR) (2014) communications@ myesr. org. Renewal of radiological equipment. Insights into imaging 5:543\u0026ndash;546\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKemerink M, Dierichs TJ, Dierichs J, Huynen HJ, Wildberger JE, van Engelshoven JM, Kemerink GJ (2011) Characteristics of a first-generation x-ray system. Radiology 259(2):534\u0026ndash;539\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJohnson DR, Kyriou J, Morton EJ, Clifton A, Fitzgerald M, Macsweeney E (2001) Radiation protection in interventional radiology. Clin Radiol 56(2):99\u0026ndash;106\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEfthymiou FO, Kakkos SK, Metaxas VI, Dimitroukas CP, Moulakakis KG, Papadoulas SI, Kouri NK, Tsimpoukis AL, Nikolakopoulos KM, Papageorgopoulou CP, Panayiotakis GS (2023) Factors influencing fluoroscopy time in endovascular treatment of abdominal aneurysms: a retrospective study. Radiat Prot Dosimetry 199(5):443\u0026ndash;452\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eUK Health Security Agency Personal Dosimetry Service. [Online]. Available from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e\u003c/span\u003e\u003cspan address=\"http://www.ukhsa-protectionservices.org.uk\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eClauss N, Kuntz S, Colvard B, Ohana M, Mertz L, Lejay A, Chakfe N (2024) Intraoperative Staff Radiation Exposure During Aortic Endovascular Procedures. Ann Vasc Surg 106:16\u0026ndash;24\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDe Ruiter QM, Gijsberts CM, Hazenberg CE, Moll FL, Van Herwaarden JA (2017) Radiation awareness for endovascular abdominal aortic aneurysm repair in the hybrid operating room. An instant patient risk chart for daily practice. J Endovasc Ther 24(3):425\u0026ndash;434\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSen I, Tenorio ER, Pitcher G, Mix D, Marcondes GB, Lima GB, Ozbek P, Oderich GS (2021) Effect of obesity on radiation exposure, quality of life scores, and outcomes of fenestrated-branched endovascular aortic repair of pararenal and thoracoabdominal aortic aneurysms. J Vasc Surg 73(4):1156\u0026ndash;1166\u003c/span\u003e\u003c/li\u003e \u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"EVAR, AAA, Endovascular aneurysm repair, Abdominal aortic aneurysm, Interventional radiology, Radiation","lastPublishedDoi":"10.21203/rs.3.rs-8555129/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8555129/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cb\u003ePurpose\u003c/b\u003e\u003c/p\u003e \u003cp\u003eA common intervention for abdominal aortic aneurysm is endovascular aneurysm repair using x-ray guided fluoroscopy. Ionising radiation carries stochastic and deterministic health risks to patients. Therefore, it is beneficial to monitor radiation doses in endovascular aneurysm repair. This project aims to compare radiation doses for endovascular aneurysm repairs performed in 2014 and in 2021 at the Leeds Teaching Hospitals Trust. Trends in screening times, and the effect of operator number on radiation dose and screening time were also investigated.\u003c/p\u003e\u003cp\u003e\u003cb\u003eMaterials \u0026amp; methods\u003c/b\u003e\u003c/p\u003e \u003cp\u003e60 cases in 2014 and 44 cases in 2021 were included. Median radiation doses and screening times in 2014 and 2021 were calculated and analysed. The effect of operator number on screening times and radiation doses was also analysed.\u003c/p\u003e\u003cp\u003e\u003cb\u003eResults\u003c/b\u003e\u003c/p\u003e \u003cp\u003eMedian radiation dose was 46.45% higher in 2021 than in 2014. In 2014, median radiation dose was lower with two operators instead of one; in 2021 operator number had no significant effect on radiation dose. Median screening time was 29% longer in 2014. In 2021 screening times were found to increase with operator number, and procedures performed with four operators had the longest screening times in 2021.\u003c/p\u003e\u003cp\u003e\u003cb\u003eConclusion\u003c/b\u003e\u003c/p\u003e \u003cp\u003eRadiation doses in endovascular aneurysm repair have increased in 2021 from 2014 and may be the result of ageing equipment. Operator number influenced radiation doses and screening time in some instances and may be an area for further research with possible implications into procedure protocol for endovascular aneurysm repair.\u003c/p\u003e","manuscriptTitle":"Audit of radiation doses during endovascular aneurysm repair","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-22 17:00:26","doi":"10.21203/rs.3.rs-8555129/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"dcaac3d5-61da-46b8-9ff6-ec41f873cd0a","owner":[],"postedDate":"February 22nd, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-03-09T15:20:07+00:00","versionOfRecord":[],"versionCreatedAt":"2026-02-22 17:00:26","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8555129","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8555129","identity":"rs-8555129","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}