Occupational exposure during endovascular aneurysm repair (EVAR) and aortoiliac percutaneous transluminal angioplasty (PTA) procedures

Two-Stage Endovascular Aneurysm Repair with Preemptive Embolization: A Retrospective Study

BACKGROUND

Type II endoleak is the most common complication of endovascular aneurysm repair. Retrograde perfusion from the aneurysmal sac side branch to the aneurysmal sac, including the inferior mesenteric artery and lumbar arteries, is associated with adverse events after endovascular aneurysm repair, such as aneurysm sac enlargement, reintervention, rupture, and abdominal aortic aneurysm-related death. Preemptive embolization of the aneurysmal sac side branch before endovascular aneurysm repair is an effective and safe procedure for preventing type II endoleak and reducing the size of the aneurysmal sac. Since 2019, we have been conducting preemptive embolization of the inferior mesenteric artery and lumbar arteries. Thus, we intended to work on a two-stage endovascular aneurysm repair in which embolization and endovascular aneurysm repair are performed on separate days, owing to concerns about prolonged operative time and increased contrast media use and radiation exposure from performing endovascular aneurysm repair simultaneously. This study aimed to evaluate the effects of a two-stage endovascular aneurysm repair.

METHODS

This retrospective study included 114 cases of endovascular aneurysm repair (95 men and 19 women) for AAA performed at our hospital between January 2019 and December 2022. Inferior mesenteric artery and lumbar artery embolization were performed simultaneously with endovascular aneurysm repair (simultaneous group) in 49 cases, and two-stage embolization was performed (two-stage group) in 30 cases. The primary endpoints included the occurrence of T2EL during follow-up and the embolization rate of the IMA or LAs.

RESULTS

Type II endoleak did not occur in the two-stage group (follow-up period: 35 ± 6.2 months), whereas it was observed in 8.2% of patients more than 6 months after EVAR in the simultaneous group (follow-up period: 28 ± 5.5 months). While the total operative time was 340 ± 111.2 min in the simultaneous group, the durations for embolization and endovascular aneurysm repair in the two-stage group were 169 ± 35.5 min and 135.0 ± 26.4 min (total time 304 ± 31.2 min, P = 0.21), respectively, indicating a reduction in the total time required for the 2 techniques. The total amounts of contrast media used in the simultaneous and two-stage groups were 200.0 ± 179.2 mL and 182.0 ± 51.2 mL (P = 0.42), respectively, and the corresponding total radiation doses were 2502.4 ± 690.5 mGy and 2114.6 ± 351.2 mGy (P = 0.28), respectively, showing a decrease in both in the two-stage group. The lumbar artery embolization rates were 74.3% and 87.9% (P < 0.01) in the simultaneous and two-stage groups, respectively, indicating a significant difference.

CONCLUSIONS

Two-stage endovascular aneurysm repair with preemptive embolization of the inferior mesenteric artery and lumbar arteries may be an effective strategy for reducing type II endoleak occurrence, overall operative time, contrast use, and overall radiation exposure.

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 effect of Fiber Optic RealShape technology on the reduction of radiation during complex endovascular surgery

OBJECTIVE

Despite the advantages that fenestrated endovascular aortic repair has over open repair, it is accompanied by the consequence of radiation exposure, which can result in long-term complications for both the patient and surgical staff. Fiber Optic RealShape (FORS) technology is a novel advancement that uses emitted light from a fiber optic wire and enables the surgeon to cannulate vessels in real time without live fluoroscopy. This technology has been implemented at select centers to study its effectiveness for cannulation of target vessels and its impact on procedural radiation.

METHODS

We collected prospective data on physician-modified endograft (PMEG) cases before and after the introduction of FORS technology. FORS PMEGs were matched with up to three conventional fluoroscopy cases by number of target vessels, inclusion of a bifurcated device below, aneurysm extent, and patient body mass index. The procedural radiation parameters were compared between these cohorts. Within the FORS cohort, we analyzed the rate of successful target vessel cannulation for all cases done with this technology (including cases other than PMEGs), and we compared the radiation between the cannulations using only FORS with those that abandoned FORS for conventional fluoroscopy.

RESULTS

Nineteen FORS PMEGs were able to be matched to 45 conventional fluoroscopy cases. Procedures that used FORS technology had significantly reduced total air kerma (527 mGy vs 964 mGy), dose area product (121 Gy∗cm2 vs 186 Gy∗cm2), fluoroscopy dose (72.1 Gy∗cm2 vs 132.5 Gy∗cm2), and fluoroscopy time (45 minutes vs 72 minutes). There was no difference in procedure length, total contrast, or digital subtraction angiography. Within FORS cases, 66% of cannulations were completed using only FORS. Cannulations using only FORS had significant reduction of navigation air kerma (5.0 mGy vs 26.5 mGy), dose area product (1.2 Gy∗cm2 vs 5.1 Gy∗cm2), and fluoroscopy time (0.6 minutes vs 2.3 minutes) compared with cannulations abandoning FORS for conventional fluoroscopy.

CONCLUSIONS

This study demonstrates the advantages of FORS for total procedural radiation as well as during individual cannulation tasks. The implementation of FORS for target vessel catheterization has the potential to decrease the total degree of radiation exposure for the patient and surgical staff during complex endovascular aortic surgeries.

A neural network-enhanced methodology for the rapid establishment of local DRLs in interventional radiology: EVAR as a case example

PURPOSE

To develop a neural network-enhanced workflow for the automatic and rapid establishment/update of local diagnostic reference levels (DRLs) in interventional radiology (IR) using endovascular aneurysm repair (EVAR) procedures as a case example.

METHODS

Radiation dose reports were collected retrospectively for 46 consecutive EVAR procedures. These reports served as demonstrative data for the development of the proposed methodology. An algorithm was developed to receive multiple dose reports, automatically extract the kerma area product (KAP), air kerma (Ka,r), number of exposure images, and fluoroscopy time (FT) from each report and calculate the first, second, third quartiles as well as the maximum and minimum values of the extracted parameters. To extract the values of interest from the dose reports, Tesseract, an open-source optical character recognition (OCR) engine was employed. Furthermore, the accuracy and time efficiency of the proposed methodology were assessed. Specifically, the values extracted from the algorithm were compared with the ground truth values and the algorithm's processing time was compared with the respective time needed to manually extract and process the values of interest.

RESULTS

The OCR-based algorithm managed to correctly recognize 182 from the 184 target values, resulting in an accuracy of 99%. Moreover, the proposed pipeline reduced the processing time for the establishment of DRLs by 98%. DRL value for EVAR procedures, set as the third quartile of KAP was found to be 551 Gy*cm2.

CONCLUSION

An accurate and time-efficient workflow was developed for the establishment of local DRLs in interventional radiology.

Patient shielding: The need for a European consensus statement

Contact shielding has been in widespread use for the last 60-70 years aiming to protect against genetic effects, cancer, and other detriment. Since 2012, studies have begun to appear in the literature that question the continued use of such shielding, especially when radiographic technology has changed so much over the intervening period This literature has culminated in several professional bodies such as the American Association of Physicists in Medicine (AAPM) and the British Institute of Radiology (BIR) issuing guidance and statements recommending against the continued routine use of patient contact shielding. Many professional societies have also endorsed these statements. National statements on the matter continue to be produced. It is notable however that the major European bodies involved in diagnostic radiology and radiation safety have not to date issued a statement on patient shielding. This commentary looks at reasons for that and argues that it is now time for a European consensus statement on patient shielding. It is the authors belief that there are advantages to building on the work done by the AAPM and BIR, using the opportunity to amplify the statements, propagate the intent of the original statements, refine the message to deal with questions that have arisen since their publication. Α working group, Gonad and Patient Shielding (GAPS) has been formed by members from a) the European Federation of Organisations for Medical Physics (EFOMP), b) the Eurosafe Imaging initiative of the European Society of Radiology (ESR), c) the European Federation of Radiographers Societies (EFRS), d) EURADOS and e) the BIR to produce a joint statement on the proper application of patient shielding in diagnostic and interventional radiology.

A novel personalized dosimetry method for endovascular aneurysm repair (EVAR) procedures

OBJECTIVE

To estimate radiation doses for the primarily irradiated organs/tissues of patients subjected to standard endovascular aneurysm repair (EVAR) procedures using a novel personalized dosimetry method.

METHODS

Dosimetric and anthropometric data were collected prospectively for eight patients who underwent standard EVAR procedures. Patient-specific Monte Carlo simulations were performed to estimate organ/tissue doses from each of the fluoroscopic and digital subtraction angiography acquisitions involved in EVAR. Individual-specific cumulative absorbed doses were estimated for the skin, spinal bone marrow, heart, kidneys, liver, colon, bladder, pancreas, stomach, and spleen and compared to corresponding values estimated through a commercially available dosimetric software package that employs standardized phantoms.

RESULTS

The highest organ/tissue radiation doses from EVAR were found for the skin, spinal bone marrow, kidneys, and spleen as 192.4 mGy, 96.7 mGy, 72.9 mGy, and 33.6 mGy respectively, while the doses to the heart, liver, colon, bladder, pancreas, and stomach were 6.3 mGy, 14.4 mGy, 18.4 mGy, 14.8 mGy, 21.6 mGy, and 11.2 mGy respectively. Corresponding dose values using standardized phantoms were found to differ up to 151%.

CONCLUSION

Considerable radiation doses may be received by primarily exposed organs/tissues during standard EVAR. The specific size/anatomy of the patient and the variation in exposure parameters/beam angulation between different projections commonly involved in EVAR procedures should be taken into account if reliable organ dose data are to be derived.

KEY POINTS

• A novel patient-specific dosimetry method was utilized to estimate radiation doses to the primarily irradiated organs/tissues of patients subjected to standard endovascular aneurysm repair procedures. • The use of standardized mathematical anthropomorphic phantoms to derive organ dose from fluoroscopically guided procedures may result in considerable inaccuracies due to differences in the assumed organ position/volume/shape compared to patients.

Factors affecting radiation exposure in endovascular repair of abdominal aortic aneurysms: a pilot study

BACKGROUND

Radiation exposure during endovascular repair (EVAR) of abdominal aortic aneurysms (AAAs) is a potential issue. Several studies have identified factors affecting radiation exposure, although they are limited. The aim of this study was to identify independent factors affecting radiation exposure in patients with AAA undergoing standard EVAR.

METHODS

Forty-eight consecutive patients underwent elective EVAR for infrarenal AAA managed between April 2019 and April 2020. Fluoroscopy time (FT) and kerma area product (KAP) were the main outcome measures.

RESULTS

Median (interquartile range) FT and KAP values were 1018 (653-1619) s and 2.68 (2.08-3.81) mGy·m², respectively. C3 Excluder graft use and main body insertion site from the right femoral were associated with significantly lower FT. Coronary artery disease, endografts with two docking limbs, AAA diameter, neck angle and length, procedure duration, contrast amount, and hospitalization were associated with significantly higher FT. Neck angle was the single independent perioperative factor related to FT higher than the median value observed in the study (P=0.004, odds ratio: 1.073, 95% confidence interval: 1.023-1.126). The use of the C3 Excluder device was associated with lower KAP. AAA diameter, neck angle, procedure duration, contrast medium amount and postoperative hospitalization were associated with higher KAP. AAA diameter was the single independent factor related to KAP higher than the median value observed in the study (P=0.013, odds ratio: 3.73, 95% confidence interval: 1.32-10.56).

CONCLUSIONS

This study has identified factors affecting radiation exposure during standard EVAR for infrarenal AAAs. These factors should be taken into account when contemplating AAA repair.

Aneurysms and dissections - What is new in the literature of 2019/2020 - a European Society of Vascular Medicine annual review

More than 6,000 publications were found in PubMed concerning aneurysms and dissections, including those Epub ahead of print in 2019, printed in 2020. Among those publications 327 were selected and considered of particular interest.

Radiation Safety Performance is More than Simply Measuring Doses! Development of a Radiation Safety Rating Scale

PURPOSE

Radiation safety performance is often evaluated using dose parameters measured by personal dosimeters and/or the C-arm, which provide limited information about teams' actual radiation safety behaviors. This study aimed to develop a rating scale to evaluate team radiation safety behaviors more accurately and investigate its reliability.

MATERIALS AND METHODS

A modified Delphi consensus was organized involving European vascular surgeons (VS), interventional radiologists, and interventional cardiologists. Initial items and anchors were drafted a priori and rated using five-point Likert scales. Participants could suggest additional items or adjustments. Consensus was defined as ≥ 80% agreement (rating ≥ 4) with Cronbach's alpha ≥ .80. Two VS with expertise in radiation safety evaluated 15 video-recorded endovascular repairs of infrarenal aortic aneurysms (EVAR) to assess usability, inter and intrarater reliability.

RESULTS

Thirty-one of 46 invited specialists completed three rating rounds to generate the final rating scale. Five items underwent major adjustments. In the final round, consensus was achieved for all items (alpha = .804; agreement > 87%): 'Pre-procedural planning', 'Preparation in angiosuite/operating room', 'Shielding equipment', 'Personal protective equipment', 'Position of operator/team', 'Radiation usage awareness', 'C-arm handling', 'Adjusting image quality', 'Additional dose reducing functions', 'Communication/leadership', and 'Overall radiation performance and ALARA principle'. All EVARs were rated, yielding excellent Cronbach's alpha (.877) with acceptable interrater and excellent intrarater reliability (ICC = .782; ICC = .963, respectively).

CONCLUSION

A reliable framework was developed to assess radiation safety behaviors in endovascular practice and provide teams with formative feedback. The final scale is provided in this publication.

Epidemic characteristics and related risk factors of occupational exposure for pediatric health care workers in Chinese public hospitals: a cross-sectional study

Background

Health care workers have a high risk of occupational exposure. However, the risk of occupational exposure for pediatric health care workers has not been acknowledged in previous studies. The purpose of this study was to investigate the occupational exposure rate of pediatric health care workers in Chinese public hospitals, to explore risk factors for occupational exposure, and to put forward corresponding countermeasures to reduce occupational exposure of pediatric health care workers and protect their physical and mental health.

Methods

A cross-sectional study was conducted with pediatric health care workers in 43 hospitals in 15 provinces in eastern, central, and western China between July and October 2018. With this sample, we computed the descriptive statistics of the demographic characteristics, calculated the frequency of various types of occupational exposure, and tested risk factors for occupational exposure using a chi-squared test and binary logistic regression analysis.

Results

Most respondents were nursing staff (61.1%) and workers with a low-ranking professional title (50.5%). The most common style of occupational exposure in our sample was a hazard in the work environment (62.6%). Notably, physicians were less likely to experience occupational exposure than nurses (OR = 0.320, 95% CI = 0.241, 0.426). Meanwhile, pediatric health care workers who interpreted the doctor-patient relationship as harmonious (OR = 0.304, 95% CI = 0.152, 0.607) were less likely to suffer occupational exposure.

Conclusion

Pediatric health care workers in Chinese public hospitals have a high occupational exposure risk and the risk factors are complex and diverse. The state, society, hospitals should acknowledge this issue and develop strategies to protect the physical and mental health of pediatric health care workers.

Reduction of radiation exposure to operating physician and assistant using a real-time auditory feedback dosimeter during femoral artery puncturing: a study on swine model

Background

Real-time dosimeters may create a relatively safer environment not only for the patient but also for the physician and the assistant as well. We propose the use of a real-time radiation measurement dosimeter having auditory feedback to reduce radiation exposure.

Methods

Radiation dose rates were measured for 30 fluoroscopy-guided puncturing procedures of femoral arteries in swine. Fifteen puncturing procedures were performed with real-time radiation measurement dosimeter having auditory feedback and other 15 were performed without auditory feedback dosimeter by an interventional cardiologist with 10 years of experience.

Results

The left body side of the operating physician (38%, p < 0.001) and assistant (25%, p < 0.001) was more exposed as compared to the right body side. Radiation dose rate to the left hand, left arm and left leg were reduced from 0.96 ± 0.10 to 0.79 ± 0.12 mSv/h (17% reduction, p < 0.001), from 0.11 ± 0.02 to 0.07 ± 0.01 mSv/h (36% reduction, p < 0.001) and from 0.22 ± 0.06 to 0.15 ± 0.02 mSv/h (31% reduction, p < 0.001) with the use of auditory feedback dosimeter, respectively. The mean fluoroscopic time was reduced from 4.8 ± 0.43 min to 4.2 ± 0.53 min (p < 0.001). The success rate of performing arterial puncturing was 100%.

Conclusions

The use of auditory feedback dosimeter resulted in reduction in effective dose. The sound beep alerted the physician from the danger of exposure, and this approach induced awareness and protective mindset to the operating physician and assistant.