Editor's Choice - European Society for Vascular Surgery (ESVS) 2023 Clinical Practice Guidelines on Radiation Safety

Radiation exposure from pre-emptive coil embolization versus secondary interventions for endoleak-induced aneurysm sac growth following endovascular abdominal aortic aneurysm repair

OBJECTIVE

Pre-emptive embolization of the inferior mesenteric artery and lumbar arteries has been shown to reduce aneurysm sac growth and secondary interventions following endovascular aneurysm repair (EVAR). It is unclear if this strategy will increase radiation exposure compared with secondary interventions performed for endoleak-induced sac growth. We examined the cumulative procedural radiation exposure associated with pre-emptive embolization of aneurysm sac branches and compared it with that of secondary interventions.

METHODS

A retrospective analysis was performed on patients who underwent EVAR for nonruptured, infrarenal abdominal aortic aneurysms (AAAs) from January 2012 to December 2022, and who were followed up until February 2024. Procedural radiation data was collected using fluoroscopy time (minutes), dose area product (DAP; μGym2), and radiation dose (mGy). Cumulative radiation exposure included pre-emptive embolization, EVAR, and any endovascular secondary interventions for sac growth.

RESULTS

There were 112 patients (90 male; mean age, 72.4 ± 8.3 years; mean AAA diameter, 58.4 ± 12.3 mm) with available radiation data. Pre-emptive embolization was associated with significantly fewer secondary interventions (8/55 [14.5%] pre-emptive embolization only vs 20/57 [35%] no pre-emptive embolization, needed secondary intervention; P = .012). Patients were grouped as follows: Group 0 (G0) no pre-emptive embolization or secondary intervention (n = 37); Group 1 (G1) pre-emptive embolization only (n = 47); Group 2 (G2) secondary intervention only (n = 20); and Group 3 (G3) both pre-emptive embolization and secondary intervention (n = 8). Fluoroscopy time, total DAP, and radiation dose from EVAR did not differ significantly among the four groups. Radiation exposure was significantly higher in those with secondary intervention only (G2: DAP, 110,567 ± 132,296 μGym2) compared with those who were pre-emptively embolized and still needed a secondary intervention (G3: DAP, 71,566 ± 49,592 μGym2; P = .0016). This is because patients with secondary interventions only required more sessions of endovascular procedures compared with those who received pre-emptive embolization and still required secondary interventions (G2: 2.2 vs G3: 1.23 sessions; P < .001). Total radiation exposure was significantly different across groups, with the highest in patients who received secondary interventions only (G2).

CONCLUSIONS

Pre-emptive embolization of aneurysm sac branches was associated with less secondary interventions for sac growth post-EVAR. Cumulative radiation exposure in patients who received pre-emptive embolization was significantly less compared with that in patients who underwent secondary interventions for endoleak-induced sac growth. Pre-emptive embolization may mitigate secondary interventions and reduce overall radiation exposure in patients with AAAs being treated with EVAR.

Editor's Choice - Reporting and Methodological Quality of Systematic Reviews Underpinning Clinical Practice Guidelines for Vascular Surgery: A Systematic Review

OBJECTIVE

Clinical practice guideline recommendations are often informed by systematic reviews. This review aimed to appraise the reporting and methodological quality of systematic reviews informing clinical practice recommendations relevant to vascular surgery.

DATA SOURCES

MEDLINE and Embase.

METHODS

MEDLINE and Embase were searched from 1 January 2021 to 5 May 2023 for clinical practice guidelines relevant to vascular surgery. Guidelines were then screened for systematic reviews informing recommendations. The reporting and methodological quality of these systematic reviews were assessed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 statement and Assessment of Multiple Systematic Reviews 2 (AMSTAR 2) 2017 tool. Pearson correlation and multiple regression analyses were performed to determine associations between these scores and extracted study characteristics.

RESULTS

Eleven clinical practice guidelines were obtained, containing 1 783 references informing guideline recommendations. From these, 215 systematic reviews were included for synthesis. PRISMA item completeness ranged 14 - 100%, with a mean of 63% across reviews. AMSTAR 2 item completeness ranged 2 - 95%, with a mean of 50%. Pearson correlation highlighted a statistically significant association between a review's PRISMA and AMSTAR 2 score (r = 0.85, p < .001). A more recent publication year was associated with a statistically significant increase in both scores (PRISMA coefficient 1.28, p < .001; and AMSTAR 2 coefficient 1.31, p < .001). Similarly, the presence of funding in a systematic review was shown to be statistically significantly associated with an increase in both PRISMA and AMSTAR 2 scores (coefficient 4.93, p = .024; and coefficient 6.07, p = .019, respectively).

CONCLUSION

Systematic reviews informing clinical practice guidelines relevant to vascular surgery were of moderate quality at best. Organisations producing clinical practice guidelines should consider funding systematic reviews to improve the quality of their recommendations.

Lucerne milestone approach for benchmarking and education: Towards ultra-low dose endovascular aortic repair

Objective

The aim of this single-center case series is to demonstrate that an ultra-low dose (ULD) can be routinely achieved in the hybrid operating room in standard endovascular aortic repair (EVAR) for infrarenal abdominal aortic aneurysm by adjusting the manufacturer's predefined imaging parameters, hardware configurations and user protocols (including benchmarking).

Methods

The hybrid operating room manufacturer predefined EVAR software setup of the dose exposure control software (OPTIQ, Siemens Healthineers, Forchheim, Germany) at our university medical center was screened for possible improvements regarding radiation dose application. Tests on a water-equivalent as well as polymethyl methacrylate phantom model to assess the impact of technical settings were performed, including comparison of settings for exposure control software, different magnification, collimation configurations and detector distance. All results were transferred into modified setups for the exposure control software and a new ULD procedure protocol for EVAR. Additionally, to standardize the clinical pathway, the Lucerne EVAR Milestone Approach (LEMA) was introduced including preoperative, perioperative, and postoperative milestones for technical procedure content and dose benchmarking during EVAR. A validation of the new settings including revised software setup, procedure protocol, and applicability of LEMA on a consecutive EVAR case series was conducted. Ten consecutive patients undergoing EVAR for low and medium complexity infrarenal abdominal aortic aneurysm were included. The primary outcome parameter was intraoperative dose area product (DAP, measured in Gy·cm2). Secondary outcomes were median fluoroscopy time (in minutes:seconds), cumulative air kerma (in mGy), clinical success, and occurrence of endoleaks.

Results

New ULD settings compared with previous manufacturers standard settings of dose exposure control software reduced DAP for both fluoroscopy (0.0382 Gy·cm2/min vs 0.3 Gy·cm2/min) and angiography (2.36 Gy·cm2/min vs 2.48 Gy·cm2/min). Digital magnification and collimation decreased DAP. Application of the new ULD standard EVAR protocol resulted in a median DAP of 5.6 Gy·cm2 (range, 3.54-12.1 Gy·cm2). Median fluoroscopy time was 16 minutes and 32 seconds. Type I endoleaks occurred in no patients (0%), type II in five patients (50%), and type III in no patients (0%). No patient had to undergo reintervention owing to endoleak or absence of diameter shrinkage during the first postoperative year.

Conclusions

Revision of the manufacturer-predefined EVAR setup by testing and ensuring optimal imaging parameters and hardware configurations in combination with LEMA enabled performance of ULD standard EVAR procedures routinely without compromising imaging quality.

Analysis of radiation exposure in endovascular treatment of chronic limb-threatening ischemia by arterial access and Global Limb Anatomic Staging System classification

OBJECTIVE

Endovascular therapy for the treatment of chronic limb-threatening ischemia (CLTI) continues to evolve with the development of new techniques and devices. However, data on radiation dose during CLTI revascularization using two different types of C-arms remains limited.

OBJECTIVE

The objective of this study was to analyze radiation dose parameters during revascularization of CLTI, considering arterial access and Global Limb Anatomic Staging System (GLASS) classification, using two different types of C-arms.

METHODS

A cross-sectional, non-randomized study of endovascular procedures was performed for the revascularization of CLTI. All procedures were performed percutaneously in two different C-arm devices: mobile (MCA) and hybrid room (HR). Procedures were stratified according to GLASS classification. The arterial accesses included antegrade femoral, contralateral femoral, brachial, and double arterial access (defined as the combination with the retrograde access). Dosimetric parameters, including air-Kerma area product (KAP), fluoroscopy time (FT), cumulative air Kerma (CAK), and contrast volume, were collected.

RESULTS

During the period from July 2020 to September 2023, 465 procedures were performed on 373 patients. Mean patient age was 73.4 years (standard deviation, 11.24 years; range, 37-99 years). The median CAK for antegrade access was significantly higher in HR compared with MCA (6.08 Gy vs 3.33 Gy; P < .001). However, the median FT was lower in HR compared with MCA (795.13 seconds vs 981 seconds; P = .039). The mean KAP was significantly higher for contralateral access (19.22 Gy‧cm2 vs 13.29 Gy‧cm2; P = .028) and double arterial access (17.4 Gy‧cm2 vs 7.35 Gy‧cm2; P = .012) in HR compared with MCA. For all three GLASS categories, the mean KAP was significantly higher in HR compared with MCA (P < .05).

CONCLUSIONS

Antegrade access showed lower KAP compared with the rest of the arterial accesses. Infrainguinal revascularizations performed in HR involve higher levels of KAP, with significant differences in all types of arterial access.

Analysis of radiation exposure learning curves for vascular surgery trainees during fluoroscopically guided interventions

OBJECTIVE

The volume of fluoroscopically guided interventions (FGIs) performed by vascular surgeons has increased significantly nationwide; however, appropriate and timely radiation safety training varies by institution. Vascular surgery trainees often learn radiation safety techniques concurrently with learning the art of vascular surgery. Given the concern for occupational hazards throughout clinical training, we sought to determine the radiation dose exposure to trainees, faculty surgeons, and patients during FGIs according to the level of training.

METHODS

A prospective cohort study was performed at a university hospital to determine the median body radiation dose of trainees, attending surgeon, and patients during FGIs over a 5-month period. Optically stimulated luminescence dosimeters were placed outside the lead apron at the thyroid and sternum positions for one attending surgeon and all assisting fellows performing FGIs. Cases were stratified according to fellow training stage: first 6 months in the first year (postgraduate year [PGY]6) and final 6 months of the second year (PGY7). Operator radiation dose was calculated based on a calibration of 80 kVp. Procedural reference air kerma (RAK), fluoroscopy time, dose area product (DAP), and patient body mass index were recorded. Scatter fractions were measured with the thyroid and sternum counts to DAP ratio and the DAP/RAK ratio (a surrogate for collimation and use of magnification). Paired Wilcoxon and χ2 tests were performed to identify statistical significance of training stage on radiation dose exposure and performance of radiation reduction.

RESULTS

A total of 40 FGIs were performed: 21 cases with PGY6 fellows and 19 cases with PGY7 fellows. Higher median thyroid and sternum radiation doses were observed for PGY6 fellows than for PGY7 fellows, respectively (82 μGy [interquartile range (IQR): 47-94 μGy] vs 44 μGy [IQR: 30-57 μGy], P = .009; 89 μGy [IQR: 75-128 μGy] vs 54 μGy [IQR: 48-77 μGy], P = .007). Scatter fractions, as measured by the thyroid/DAP and sternum/DAP ratios, were significantly higher for first-year fellows (2 vs 1, P = .018; 2.64 vs 1.23, P = .041). There was no difference in the source-to-image distance or the average field size as measured by the DAP/RAK ratio.

CONCLUSIONS

Trainee radiation dose exposure is higher during the first year of fellowship. Acquisition of optimal performance with fluoroscopy skills can be related to training time. The difference noted between PGY6 and PGY7s is likely enhanced for vascular residents (PGY1-5) and further underscores the importance of early and thorough education in radiation safety for all trainees.

Low Profile Off the Shelf Multibranched Endografts for Urgent Endovascular Repair of Complex Aortic and Thoraco-abdominal Aneurysms in Patients with Hostile Iliac Access: European Multicentre Observational Study

OBJECTIVE

The aim of the study was to report outcomes of a thoraco-abdominal, custom made, low profile (outer diameter 20 F) four branched endograft used as an off the shelf (OTS) solution for urgent juxta- and pararenal abdominal aortic aneurysms (JP-AAAs) and thoraco-abdominal aortic aneurysms (TAAAs) in the presence of hostile femoral or iliac access.

METHODS

Data for patients who underwent endovascular repair for urgent JP-AAAs and TAAAs with hostile femoral or iliac access by a low profile, four branched endograft in four European aortic centres between 2019 and 2023 were collected prospectively and analysed retrospectively. The investigated device was a custom made endograft with the configuration of a standard t-Branch, used as an OTS solution for urgent cases with hostile femoral or iliac access. Access related complications, spinal cord ischaemia (SCI), and 30 day death were assessed as primary outcomes. Survival, freedom from re-interventions (FFRs), and iliac limb occlusion (ILO) were evaluated as secondary outcomes.

RESULTS

Fifty five cases were enrolled: ruptures, n = 14 (25%); symptomatic, n = 12 (22%); and asymptomatic TAAAs with diameter ≥ 80 mm, n = 29 (53%). There were seven (13%) JP-AAAs and 48 (87%) TAAAs. The median right and left external iliac artery diameters were 6.7 (interquartile range [IQR] 5.5, 7.9) mm and 7.1 (IQR 6.5, 8.7) mm, respectively. Bilateral hostile femoral or iliac access was reported in 39 patients (71%). Access related complications occurred in five cases (9%). There were four cases (7%) of SCI with two permanent paraplegias. Four patients (7%) died within 30 days. The median follow up was 22 (IQR 11, 33) months. Overall, eight patients (15%) required re-interventions: four within 30 days and four during follow up. No ILO occurred. Estimated one year FFRs and survival were 91% and 87%, respectively.

CONCLUSION

Low profile OTS thoraco-abdominal endografts seems safe and effective to manage urgent JP-AAAs and TAAAs in the presence of hostile femoral or iliac access. Further larger studies with long term follow up are needed to validate this preliminary experience.

[New innovations in cross-sectional imaging diagnostics of the aorta]

Imaging, particularly computed tomography (CT) and magnetic resonance imaging (MRI), plays a central role in the diagnostics, treatment planning and follow-up of aortic diseases. While ultrasound is often used for the initial assessment, CT enables rapid and comprehensive imaging of the aorta. The MRI is a radiation-free and when necessary, contrast agent-free alternative and provides functional imaging methods. Positron emission tomography (PET) is particularly relevant for inflammatory vascular diseases. Cross-sectional imaging has recently undergone significant development, particularly with respect to image quality and the required doses of ionizing radiation and contrast agents, spatial resolution and newer methods, such as material decomposition and functional imaging. This article provides an overview of current developments in CT angiography (CTA) and magnetic resonance angiography (MRA) and their use in selected aortic diseases in the context of the latest guidelines.

Implementation of a Comprehensive Endovascular Aortic Programme and Maintenance of Clinical Excellence during Fenestrated Branched Endovascular Aortic Repair in Two Centres

OBJECTIVE

Comprehensive endovascular aortic programmes need optimal infrastructure and multidisciplinary teams to manage complex aortic aneurysms. This study assessed the implementation of such a programme in two centres and its impact on fenestrated or branched endovascular aortic repair (FB-EVAR) outcomes.

METHODS

A retrospective review of patients treated for complex abdominal and thoraco-abdominal aortic aneurysms (TAAAs) by FB-EVAR between 2013 and 2023 was undertaken. All FB-EVAR patients were analysed, including investigational trials and high risk patients with physician modified endografts. Centre 1 (2013 - 2020) and Centre 2 (2020 - 2023) were compared. Primary endpoints were 30 day and or in hospital mortality and major adverse event (MAE) rates. Secondary endpoints were procedural metrics, spinal cord injuries, freedom from all cause death, failure to rescue, and one year mortality and re-intervention rates.

RESULTS

A total of 629 patients were included (475, 75.5% at Centre 1 and 154, 24.5% at Centre 2). The median age was 74 years (interquartile range 68, 79) and 441 (70.1%) were male. Centre 2 had a higher proportion of American Society of Anesthesiology class ≥ 3, genetically triggered aortic diseases (p = .002), chronic post-dissection aneurysms, prior aortic repairs, TAAAs (each p < .001), and symptomatic, larger aneurysms (p < .021). Technical success rates were similar between centres (97.9% vs. 98.1%; p = .91). The early mortality rate was 1.1% (7/629) with no statistically significant difference. No statistically significant differences (p > .050) in new onset permanent dialysis (0.6% vs. 2.0%), major stroke (0.6% vs. 0.6%), and permanent paraplegia (0.8% vs. 2.0%) were observed. Failure to rescue rates were 5.3% in Centre 2 and 3.5% in Centre 1 (p = .74). The one year mortality rate (91% vs. 89%; p = .71) and re-intervention rate (sub-distribution hazard ratio 1.30; p = .21) were similar between centres.

CONCLUSION

FB-EVAR was performed with low mortality and risk of disabling complication rates. No differences in mortality and MAE rates were observed after establishing a comprehensive endovascular programme, despite higher risk and more extensive cases at the new institution.

Volume Measurements for Surveillance after Endovascular Aneurysm Repair using Artificial Intelligence

OBJECTIVE

Surveillance after endovascular aneurysm repair (EVAR) is suboptimal due to limited compliance and relatively large variability in measurement methods of abdominal aortic aneurysm (AAA) sac size after treatment. Measuring volume offers a more sensitive early indicator of aneurysm sac growth or regression and stability, but is more time consuming and thus less practical than measuring maximum diameter. This study evaluated the accuracy and consistency of the artificial intelligence (AI) driven software PRAEVAorta 2 and compared it with an established semi-automated segmentation method.

METHODS

Post-EVAR aneurysm sac volumes measured by AI were compared with a semi-automated segmentation method (3mensio software) in patients with an infrarenal AAA, focusing on absolute aneurysm volume and volume evolution over time. The clinical impact of both methods was evaluated by categorising patients as showing either AAA sac regression, stabilisation, or growth comparing the 30 day and one year post-EVAR computed tomography angiography (CTA) images. Inter- and intra-method agreement were assessed using Bland-Altman analysis, the intraclass correlation coefficient (ICC), and Cohen's κ statistic.

RESULTS

Forty nine patients (98 CTA images) were analysed, after excluding 15 patients due to segmentation errors by AI owing to low quality CT scans. Aneurysm sac volume measurements showed excellent correlation (ICC = 0.94, 95% confidence interval [CI] 0.88 - 0.99) with good to excellent correlation for volume evolution over time (ICC = 0.85, 95% CI 0.75 - 0.91). Categorisation of AAA sac evolution showed fair correlation (Cohen's κ = 0.33), with 12 discrepancies (24%) between methods. The intra-method agreement for the AI software demonstrated perfect consistency (bias = -0.01 cc), indicating that it is more reliable compared with the semi-automated method.

CONCLUSION

Despite some differences in AAA sac volume measurements, the highly consistent AI driven software accurately measured AAA sac volume evolution. AAA sac evolution classification appears to be more reliable than existing methods and may therefore improve risk stratification post-EVAR, and could facilitate AI driven personalised surveillance programmes. While high quality CTA images are crucial, considering radiation exposure is important, validating the software with non-contrast CT scans might reduce the radiation burden.

Editor's Choice - European Journal of Vascular and Endovascular Surgery Publication Standards for Reporting Vascular Surgical Research

OBJECTIVE

Manuscripts submitted to the European Journal of Vascular and Endovascular Surgery (EJVES) often contain shortcomings in baseline scientific principles and incorrectly applied methodology. Consequently, the editorial team is forced to offer post hoc repair in an attempt to support the authors to improve their manuscripts. This repair could theoretically have been prevented by providing more clear definitions and reporting standards to serve researchers when planning studies and eventually writing their manuscripts. Therefore, the general principles for EJVES publication standards are summarised here.

METHODS

These publication standards did not follow a systematic approach but reflect the common opinion of the current Senior and Section Editors team. This team decided to only include recommendations regarding the most common pathologies in vascular surgery in this first edition of publication standards, namely carotid artery disease, abdominal aortic aneurysm (AAA), peripheral arterial occlusive disease (PAOD), and chronic venous disease. In future editions, the plan is to expand the areas of research.

RESULTS

Presented are (1) a common set of minimum but required publication standards applicable to every report, e.g., patient characteristics, study design, treatment environment, selection criteria, core outcomes of interventions such as 30 day death and morbidity, and measures for completeness of data including outcome information, and (2) a common set of minimum publication standards for four vascular areas.

CONCLUSION

The editors of the EJVES propose universally accepted definitions and publication standards for carotid artery disease, AAA, PAOD, and chronic venous disease. This will enable the development of a convincing body of evidence to aid future clinical practice guidelines and drive clinical practice in the right direction. These first ever publication and reporting standards for EJVES aim to improve future research published in the journal.

Advanced Imaging Techniques for Complex Endovascular Aortic Repair: Preoperative, Intraoperative and Postoperative Advancements

BACKGROUND

Endovascular aortic repair (EVAR) requires extensive preoperative, intraoperative, and postoperative imaging for planning, surveillance, and detection of endo-leaks. There have been manyadvancements in imaging modalities to achieve this purpose. This review discussed different imaging modalities used at different stages of treatment of complex EVAR.

METHODS

We conducted a literature review of all the imaging modalities utilized in EVAR by searching various databases.

RESULTS

Preoperative techniques include analysis of images obtained via modified central line using analysis software and intravascular ultrasound. Fusion imaging (FI), carbon dioxide (CO2) angiography, intravascular ultrasound, and Fiber Optic RealShape (FORS) technology have been crucial in obtaining real-time imaging for the detection of endo-leaks during operative procedures. Conventional imaging modalities like computed tomography (CT) angiography (CTA) and magnetic resonance (MR) angiography are still employed for postoperative surveillance along with computational fluid dynamics and contrast-enhanced ultrasound (CEUS). The advancements in artificial intelligence (AI) have been the breakthrough in developing robust imaging applications.

CONCLUSIONS

This review explains the advantages, disadvantages, and side-effect profile of the abovementioned imaging modalities.

Case report of a delayed diagnosis of radiation induced ulcer in a patient following angioplasty

Diagnosis of fluoroscopy-induced radiodermatitis remains challenging for dermatologists. We present a case report where a patient had predictable risks of developing chronic radiodermatitis, yet the diagnostic was delayed for over a year and a half. In the current absence of appropriate follow-ups in some institutions, dermatologists should keep high suspicion for chronic fluoroscopy-induced radiodermatitis when encountering lesions characteristic of radiation dermatitis without a history of radiotherapy, prompting the necessity to inquire about antecedents of fluoroscopy-guided interventions.

Endovascular repair of bilateral common iliac artery aneurysms using intraoperative positioning system

Intraoperative positioning system (IOPS; Centerline Biomedical, Inc) is a novel technology that allows for real-time intravascular navigation of endovascular devices using an electromagnetic field. In this report, we describe the use of IOPS for effective treatment of bilateral common iliac artery aneurysms with endovascular aortoiliac repair using iliac branch endoprostheses. Our experience suggests that this technology has the potential to reduce radiation and contrast use in endovascular procedures, although its application is currently limited. To the best of our knowledge, this is the first reported case of bilateral internal iliac cannulations for iliac branch endoprosthesis placement using IOPS.

Intraoperative Staff Radiation Exposure During Aortic Endovascular Procedures

BACKGROUND

The risk of radiation exposure in the surgical operating room (OR) and/or catheterization laboratory is now well established. Complex endovascular procedures often require multiple approaches and different positioning of the staff members around the patient, potentially increasing the levels of radiations exposure. Our goal was to evaluate the levels of radiation exposure of the members of the staff during endovascular aortic procedures in order to propose radioprotection optimization.

METHODS

We included 41 aortic endovascular procedures out of 114 procedures performed between January 12, 2014, and August 31, 2015, including 24 standard endovascular aortic aneurysm repair (EVAR), 7 EVAR with iliac branch (EVARib), 8 complex fenestrated/branched EVAR (F/B EVAR), and 2 thoracic EVAR (TEVAR). Procedures were performed in an OR equipped with a carbon fiber table and a mobile fluoroscopy C-arm. We collected the usual dosimetry data given by the C-arm as well as the patient's peak skin dose (PSD). In all staff members, radiation exposure was measured with thermoluminescent chip dosimeters placed on both temples, on posterior sides of both hands, and on both lower legs.

RESULTS

PSD levels were low for EVAR because 24 patients had values below the reading threshold. PSD significantly increased with more complex procedures. Main operator (MO) received the higher level of irradiation on whole body, hands, and ankles. Eye lenses irradiation was higher on both assistant operators (AOs). Other members received low levels of irradiation. We found a high ranges of radiation exposure with a high risk of exposure for the AO, mainly for F/B EVAR and EVARib.

CONCLUSIONS

Even if all personal protections are used, staff positioning is a major point that must be considered. If MO is supposed to be the most exposed to X-rays, specific conditions of positioning of the AO may be at risk of exposure.

National Diagnostic Reference Levels for Standard Descending Thoracic Endovascular Aortic Repair and Optimisation Strategies

OBJECTIVE

The International Commission on Radiological Protection has highlighted the large number of medical specialties that use fluoroscopy outside diagnostic imaging departments without radiation protection programmes for patients and staff. Vascular surgery is one of these specialties. Thoracic endovascular aortic repair (TEVAR) is a complicated procedure requiring radiation protection guidance and optimisation. The recent EU Basic Safety Standards Directive requires the use and periodic updating of diagnostic reference levels (DRLs) for interventional procedures. The aim of this study was to determine doses for patients undergoing TEVAR with mobile Xray systems and hybrid rooms (fixed Xray systems) to obtain national DRLs and to suggest optimisation actions.

METHODS

This was a retrospective cross sectional study. The Spanish Chapter of Endovascular Surgery conducted a national survey in 11 autonomous communities representing around 77.6% of the Spanish population (47.33 million inhabitants). A total of 266 TEVAR procedures from 17 Spanish centres were analysed, of which 53.0% were performed in hybrid operating rooms. National DRLs were obtained and defined as the third quartile of the median values from the different participating centres.

RESULTS

The proposed national DRLs are: for kerma area product (KAP), 113.81 Gy·cm2 for mobile Xray systems and 282.59 Gy·cm2 for hybrid rooms; and for cumulative air kerma (CAK) at the patient entry reference point, 228.38 mGy for mobile systems and 910.64 mGy for hybrid rooms.

CONCLUSION

Based on the requirement to know radiation doses for standard endovascular procedures, this study of TEVARs demonstrated that there is an increased factor of 2.48 in DRLs for KAP when the procedure is performed in a hybrid room compared with mobile C-arm systems, and an increased factor of 3.98 in DRLs for CAK when the procedure is performed with hybrid equipment. These results will help to optimise strategies to reduce radiation doses during TEVAR procedures.

Lowest reported dose area product of 2.4 Gy∗cm2 for ultra-low-dose endovascular aortic aneurysm repair of a standard infrarenal aortic aneurysm

This is a report of successful treatment of an abdominal aortic aneurysm via standard endovascular aortic repair with an ultra-low dose (ULD) of 2.4 Gy∗cm2 using the latest imaging software in a hybrid operating room. To the best of our knowledge, no case has yet been reported achieving a successful outcome with such ULD values to date. The key factors to achieving an ULD regarding the dose area product comprise the right technology, procedural standardization, and team education and training. This case highlights the potential for reducing the radiation dose routinely for patients and staff alike, especially for operating room staff with daily radiation exposure.

A procedural step analysis of radiation exposure in fenestrated endovascular aortic repair

OBJECTIVE

Radiation exposure during complex endovascular aortic repair may be associated with tangible adverse effects in patients and operators. This study aimed to identify the steps of highest radiation exposure during fenestrated endovascular aortic repair (FEVAR) and to investigate potential intraoperative factors affecting radiation exposure.

METHODS

Prospective data of 31 consecutive patients managed exclusively with four-fenestration endografts between March 1, 2020, and July 1, 2022 were retrospectively analyzed. Leveraging the conformity of the applied technique, every FEVAR operation was considered a combination of six overall stages composed of 28 standardized steps. Intraoperative parameters, including air kerma, dose area product, fluoroscopy time, and number of digital subtraction angiographies (DSAs) and average angulations were collected and analyzed for each step.

RESULTS

The mean procedure duration and fluoroscopy time was 140 minutes (standard deviation [SD], 32 minutes), and 40 minutes (SD, 9.1 minutes), respectively. The mean air kerma was 814 mGy (SD, 498 mGy), and the mean dose area product was 66.8 Gy cm2 (SD, 33 Gy cm2). The percentage of air kerma of the entire procedure was distributed throughout the following procedure stages: preparation (13.9%), main body (9.6%), target vessel cannulation (27.8%), stent deployment (29.1%), distal aortoiliac grafting (14.3%), and completion (5.3%). DSAs represented 23.0% of the total air kerma. Target vessel cannulation and stent deployment presented the highest mean lateral angulation (67 and 63 degrees, respectively). Using linear regression, each minute of continuous fluoroscopy added 18.9 mGy of air kerma (95% confidence interval, 17.6-20.2 mGy), and each DSA series added 21.1 mGy of air kerma (95% confidence interval, 17.9-24.3 mGy). Body mass index and lateral angulation were significantly associated with increased air kerma (P < .001).

CONCLUSIONS

Cannulation of target vessels and bridging stent deployment are the steps requiring the highest radiation exposure during FEVAR cases. Optimized operator protection during these steps is mandatory.

Evolutionary trends and innovations in cardiovascular intervention

Cardiovascular diseases remain a global health challenge, prompting continuous innovation in medical technology, particularly in Cardiovascular MedTech. This article provides a comprehensive exploration of the transformative landscape of Cardiovascular MedTech in the 21st century, focusing on interventions. The escalating prevalence of cardiovascular diseases and the demand for personalized care drive the evolving landscape, with technologies like wearables and AI reshaping patient-centric healthcare. Wearable devices offer real-time monitoring, enhancing procedural precision and patient outcomes. AI facilitates risk assessment and personalized treatment strategies, revolutionizing intervention precision. Minimally invasive procedures, aided by robotics and novel materials, minimize patient impact and improve outcomes. 3D printing enables patient-specific implants, while regenerative medicine promises cardiac regeneration. Augmented reality headsets empower surgeons during procedures, enhancing precision and awareness. Novel materials and radiation reduction techniques further optimize interventions, prioritizing patient safety. Data security measures ensure patient privacy in the era of connected healthcare. Modern technologies enhance traditional surgeries, refining outcomes. The integration of these innovations promises to shape a healthier future for cardiovascular procedures, emphasizing collaboration and research to maximize their transformative potential.

Development, Feasibility, and Knowledge Impact of a Massive Open Online Course on Radiation Safety: A Multicentre Prospective Cohort Study

OBJECTIVE

This study reports the development of an innovative, interactive Massive Open Online Course (MOOC) teaching radiation safety principles in the vascular workplace, using stepwise e-learning with multiple choice question tests (MCQs), educational videos, and a serious game. The aim was to study the MOOC impact on radiation safety knowledge and assess its feasibility and acceptability.

METHODS

An international multicentre prospective study included team members active in the hybrid operating room. The MOOC was offered voluntarily via a secure online learning platform. A standardised MCQ test (15 questions) assessed radiation safety knowledge pre- and post-course (range 0 - 100%). Acceptability and feasibility were tested via the previously validated, Evaluating e-learning system success (EESS) model, using five point Likert scales.

RESULTS

In eight centres across four countries, 150 of 203 invited endovascular team members consented. Over a seven week study period, surgeons (28%, including vascular surgery trainees and consultants), nurses (27%, including scrub, circulating and anaesthetic nurses), anaesthetists (43%, including trainees and consultants), and radiographers (3%) participated. Of those, 67% completed the course. The average radiation knowledge improved by 22.8% (95% CI 19.5 - 26.0%; p < .001) after MOOC completion, from 48% to 71% (standard deviation [SD] 14 and 15% respectively), requiring a mean time investment of 169 minutes (SD 89 minutes). In centres with a radiographer, mean knowledge gain after MOOC completion was significantly smaller (14%, SD 19% vs. 24%, SD 16%, p = .036). The course was deemed feasible and acceptable according to the EESS model with a total mean score of 3.68/5.

CONCLUSION

This newly developed, multimodal MOOC was deemed feasible and effective across multiple international centres. The MOOC significantly contributes to radiation safety education of the entire endovascular team, improving radiation safety knowledge. The course may optimise workplace radiation safety behaviour and therefore enhance team and patient safety.

Editor's Choice - Radiation Dose Reduction During Contralateral Limb Cannulation Using Fiber Optic RealShape Technology in Endovascular Aneurysm Repair

OBJECTIVE

The increasing number of endovascular procedures has resulted in an increasing radiation burden, particularly for the treatment team. Fiber Optic RealShape (FORS) technology uses laser light instead of fluoroscopy to visualise the endovascular guidewire and catheters. These devices can be used during the navigational part of procedures, such as cannulation of the contralateral limb (CL) in endovascular aneurysm repair (EVAR). The aim of this study was to describe the effect of using FORS on radiation dose during CL cannulation in standard EVAR.

METHODS

This was a non-randomised, retrospective comparison study of prospectively collected, single centre data from FORS guided EVAR compared with a conventional fluoroscopy only guided EVAR cohort. A total of 27 FORS guided cases were matched 1:1 based on sex, age, and body mass index (BMI) with 27 regular (fluoroscopy only) EVARs. This study primarily focused on (1) technical success of FORS and (2) navigation time and radiation dose (cumulative air kerma [CAK], air kerma area product [KAP], and fluoroscopy time [FT]) during cannulation of the CL. In addition, overall procedure time and radiation dose of the complete EVAR procedure were studied.

RESULTS

In 22 (81%) of the 27 FORS guided cases the CL was successfully cannulated using FORS. All radiation dose parameters were significantly lower in the FORS group (CAK, p < .001; KAP, p = .009; and FT, p < .001) for an equal navigation time (p = .95). No significant differences were found when comparing outcomes of the complete procedure.

CONCLUSION

Use of FORS technology significantly reduces radiation doses during cannulation of the CL in standard EVAR.

The addition of a leaded arm sleeve to leaded aprons further decreases operator upper outer quadrant chest wall radiation dose during fluoroscopically guided interventions

OBJECTIVE

Breast cancer most commonly occurs in the upper outer quadrant (UOQ) chest wall (CW). The effectiveness of routine leaded aprons to protect this region of the body in interventionalists during fluoroscopically guided interventions (FGIs) is unknown. Given the high lifetime attributable risks of prolonged occupational exposure to ionizing radiation and the increasing number of practicing female vascular surgeons and interventionalists, we sought to determine if the use of a leaded arm shield would offer additional protection to the lateral CW and axilla in operators compared with routine leaded aprons.

METHODS

Effectiveness of leaded sleeves in attenuating radiation dose to the axilla and UOQ was evaluated in clinical practice and simulated scenarios. In the clinical setting, optically stimulated luminescence nanoDot detectors were placed at the UOQ lateral CW position, both over and under a standard leaded apron vest with and without the addition of an antimony/bismuth Enviro-Lite sleeve on two vascular surgeons performing FGIs. In the simulation, nanoDots were similarly placed on an anthropomorphic phantom positioned to represent a primary operator performing right femoral access. Fluorography was performed on 12-inch-thick acrylic scatter phantom at 80 kVp for an exposure of 3 Gy reference air kerma. Experiments were done with and without the sleeve. Paired Wilcoxon and χ2 tests were performed to identify the statistical significance of radiation attenuation.

RESULTS

Operator UOQ CW dose was measured during 61 FGIs: 33 cases (54%) with and 28 cases (46%) without the sleeve. Median procedure reference air kerma and fluoroscopy time was 180 mGy (interquartile range [IQR], 85-447 mGy) and 21 minutes (IQR, 11-39 minutes) when the sleeve was worn vs 100 mGy (IQR, 67-270 mGy) and 11 minutes (IQR, 6.3-25 minutes) without the sleeve. Radiation dose to the operator's UOQ was reduced by 96% (IQR, 85%-96%) when the sleeve was present and by 62% (IQR, 44%-82%; P < .001) without the sleeve. In the simulated setting, the sleeve reduced the radiation dose to the UOQ compared with the apron alone (96% vs 67%; P < .001).

CONCLUSIONS

Routine leaded aprons do attenuate the majority of UOQ chest wall radiation dose; however, the addition of a lead-equivalent sleeve further significantly reduces this dose. Because this area of the body has a high incidence of cancer formation, additional protection, especially to female interventionalists, seems prudent. Vascular surgeons should consider using a protective sleeve with their personal protective equipment when performing complex fluoroscopically guided procedures.

The Effect of a Suspended Radiation Protection System on Occupational Radiation Doses During Infrarenal EVAR Procedures: A Randomised Controlled Study

OBJECTIVE

To compare the protective effect of Zero Gravity (ZG) with conventional radiation protection during endovascular aneurysm repair (EVAR). Secondly, user experience was surveyed with a questionnaire on ergonomics.

METHODS

This was a single centre, prospective, randomised, two arm trial where 71 consecutive elective infrarenal EVAR procedures were randomised into two groups: (1) operator using ZG and assistant using conventional protection (n = 36), and (2) operator and assistant using conventional radiation protection (n = 35). A movable floor unit ZG system consists of a lead shield (1.0 mm Pb equivalent) for the front of the body and 0.5 mm Pb equivalent acrylic shielding for the head and neck. The ZG also includes arm flaps of 0.5 mm Pb equivalent covering the arm up to the elbow. Deep dose equivalent values, Hp(10) were measured with direct ion storage dosimeters (DIS) placed on various anatomical regions of the operator (axilla, chest, abdomen, and lower leg). Personal dose equivalent values, Hp(3) to eye lenses were measured in the operating and assisting surgeon using thermoluminescence dosimeters. The study was registered at the US National Institute of Health #NCT04078165.

RESULTS

Protection with the standard protection was superior in chest (0.0 vs. 0.1 μSv), abdomen (0.0 vs. 0.6 μSv), and lower leg (0.4 vs. 2.2 μSv) (p < .001). On the other hand, the ZG system yielded better shielding for the axilla (1.5 vs. 0.0 μSv) and eyes (6.3 vs. 1.1 μSv) of the operator. The use of ZG hampered the deployment of ancillary shields, which is particularly relevant for protection of the assisting surgeon. Users found ZG more cumbersome than conventional garments, it also impaired communication and reduced field of view.

CONCLUSION

Both ZG and conventional radiation protection reduced radiation exposure. Conventional protection allows better manoeuvrability at the price of wider exposure of the upper arm and axilla. ZG indirectly impaired protection of the assistant.

Monte Carlo Dosimetry Validation for X-Ray Guided Endovascular Procedures

BACKGROUND

Endovascular treatment is continuously gaining ground in vascular surgery procedures. However, current patient radiation dose estimation does not take into account the exact patient morphology and organs' composition. Monte Carlo (MC) simulation can accurately estimate the dose by recreating the irradiation process generated during X-ray-guided interventions. This study aimed to validate the MC simulation models by comparing simulated and measured dose distributions in endovascular aortic aneurysm repair (EVAR) procedures.

METHODS

We conducted a clinical study in patients treated for EVAR. Patient dose measurements were taken with passive dosimeters using Optically Stimulated Luminescence technology in 4 specific anatomical points on the skin: xiphoid process, pubic symphysis, right and left iliac crest. Dose measurements were compared to the corresponding simulated doses with the Geant4 Application for Emission Tomography (GATE) and GPU Geant4-based Monte Carlo Simulations (GGEMS) MC simulations softwares. The MC simulation took as input the computed tomography scan of the patient and the parameters of the imaging system (orientation angles, tube voltage, and aluminum filtration) and gives as output the three-dimensional (3D) dose map for each patient and angulation.

RESULTS

A good agreement with real doses was found for doses simulated by the MC GATE method (P < 0.0001; r = 0.97; 95% confidence interval [CI] [0.96-0.98]), as well as for doses simulated by the GGEMS method (P < 0.0001; r = 0.96; 95% CI [0.94-0.97]). The mean relative error for all measurements was 5 ± 5% in the MC GATE group and 6 ± 5% in the GGEMS group. Process execution on GGEMS (6 sec) was faster than the GATE MC simulation (5 hr).

CONCLUSION

Considering the current imaging settings, this study shows the potential of using the GATE and GGEMS MC simulations platforms to model the 3D dose distributions during EVAR procedures.

Editor's Choice -- European Society for Vascular Surgery (ESVS) 2024 Clinical Practice Guidelines on the Management of Abdominal Aorto-Iliac Artery Aneurysms

OBJECTIVE

The European Society for Vascular Surgery (ESVS) has developed clinical practice guidelines for the care of patients with aneurysms of the abdominal aorta and iliac arteries in succession to the 2011 and 2019 versions, with the aim of assisting physicians and patients in selecting the best management strategy.

METHODS

The guideline is based on scientific evidence completed with expert opinion on the matter. By summarising and evaluating the best available evidence, recommendations for the evaluation and treatment of patients have been formulated. The recommendations are graded according to a modified European Society of Cardiology grading system, where the strength (class) of each recommendation is graded from I to III and the letters A to C mark the level of evidence.

RESULTS

A total of 160 recommendations have been issued on the following topics: Service standards, including surgical volume and training; Epidemiology, diagnosis, and screening; Management of patients with small abdominal aortic aneurysm (AAA), including surveillance, cardiovascular risk reduction, and indication for repair; Elective AAA repair, including operative risk assessment, open and endovascular repair, and early complications; Ruptured and symptomatic AAA, including peri-operative management, such as permissive hypotension and use of aortic occlusion balloon, open and endovascular repair, and early complications, such as abdominal compartment syndrome and colonic ischaemia; Long term outcome and follow up after AAA repair, including graft infection, endoleaks and follow up routines; Management of complex AAA, including open and endovascular repair; Management of iliac artery aneurysm, including indication for repair and open and endovascular repair; and Miscellaneous aortic problems, including mycotic, inflammatory, and saccular aortic aneurysm. In addition, Shared decision making is being addressed, with supporting information for patients, and Unresolved issues are discussed.

CONCLUSION

The ESVS Clinical Practice Guidelines provide the most comprehensive, up to date, and unbiased advice to clinicians and patients on the management of abdominal aorto-iliac artery aneurysms.

Radiation Overuse in Intensive Care Units

Radiological imaging is essential for acute patient management in Intensive Care Units (ICUs); however, it introduces the risk of exposure to ionizing radiation. This review synthesizes research on radiation exposure in ICU settings, highlighting its rise during the COVID-19 pandemic and the rise in repetitive imaging. Our analysis extends to radiation safety thresholds, revealing that some ICU patients exceed the diagnostic reference level, emphasizing the need to balance diagnostic utility against potential long-term risks, such as cancer. Prospective studies have demonstrated an increase in the median cumulative effective dose in patients with trauma over time, prompting calls for improved awareness and monitoring. Moreover, innovative dose-reduction strategies and optimized protocols, especially in neuro-ICUs, promise to mitigate these risks. This review highlights the essential but risky role of radiological imaging in critical care. It advocates for rigorous radiation management protocols to safeguard patient health while ensuring the continuity of high-quality medical care.