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

Patients' Radiation Exposure During Endovascular Abdominal Aortic Aneurysm Repair

BACKGROUND

To investigate associations between patient characteristics, intraprocedural complexity factors, and radiation exposure to patients during endovascular abdominal aortic aneurysm repair (EVAR).

METHODS

Elective standard EVAR procedures between January 2015 and December 2020 were retrospectively analyzed. Patient characteristics and intraprocedural data (i.e., type of device, endograft configuration, additional procedures, and contralateral gate cannulation time [CGCT]) were collected. Dose area product (DAP) and fluoroscopy time were considered as measurements of radiation exposure. Furthermore, effective dose (ED) and doses to internal organs were calculated using PCXMC 2.0 software. Descriptive statistics, univariable, and multivariable linear regression were applied to investigate predictors of increased radiation exposure.

RESULTS

The 99 patients were mostly male (90.9%) with a mean age of 74 ± 7 years. EVAR indications were most frequently abdominal aortic aneurysm (93.9%), penetrating aortic ulceration (2.0%), focal dissection (2.0%), or subacute rupture of infrarenal abdominal aortic aneurysm (2.0%). Median fluoroscopy time was 19.6 minutes (interquartile range [IQR], 14.1-29.4) and median DAP was 86,311 mGy cm2 (IQR, 60,160-130,385). Median ED was 23.2 mSv (IQR, 17.0-34.8) for 93 patients (93.9%). DAP and ED were positively correlated with body mass index (BMI) and CGCT. Kidneys, small intestine, active bone marrow, colon, and stomach were the organs that received the highest equivalent doses during EVAR. Higher DAP and ED values were observed using the Excluder endograft, other bi- and tri-modular endografts, and EVAR with ≥2 additional procedures. Multivariable linear regression analysis revealed that BMI, ≥2 additional procedures during EVAR, and CGCT were independent positive predictors of DAP and ED levels after accounting for endograft type.

CONCLUSIONS

Patient-related and procedure-related factors such as BMI, ≥2 additional procedures during EVAR, and CGCT resulted predictors of radiation exposure for patients undergoing EVAR, as quantified by higher DAP and ED levels. The main intraprocedural factor that increased radiation exposure was CGCT. These data can be of importance for better managing radiation exposure during EVAR.

Transatlantic multicenter study on the use of a modified preloaded delivery system for fenestrated endovascular aortic repair

OBJECTIVE

Analyze the outcomes of endovascular complex abdominal and thoracoabdominal aortic aneurysm repair using the Cook fenestrated device with the modified preloaded delivery system (MPDS) with a biport handle and preloaded catheters.

METHODS

A multicenter retrospective single arm cohort study was performed, including all consecutive patients with complex abdominal aortic aneurysm repair and thoracoabdominal aortic aneurysms treated with the MPDS fenestrated device (Cook Medical). Patient clinical characteristics, anatomy, and indications for device use were collected. Outcomes, classified according to the Society for Vascular Surgery reporting standards, were collected at discharge, 30 days, 6 months, and annually thereafter.

RESULTS

Overall, 712 patients (median age, 73 years; interquartile range [IQR], 68-78 years; 83% male) from 16 centers in Europe and the United States treated electively were included: 35.4% (n = 252) presented with thoracoabdominal aortic aneurysms and 64.6% (n = 460) with complex abdominal aortic aneurysm repair. Overall, 2755 target vessels were included (mean ,3.9 per patient). Of these, 1628 were incorporated via ipsilateral preloads using the MPDS (1440 accessed from the biport handle and 188 from above). The mean size of the contralateral femoral sheath during target vessel catheterization was 15F ± 4, and in 41 patients (6.7%) the sheath size was ≤8F. Technical success was 96.1%. Median procedural time was 209 minutes (IQR, 161-270 minutes), contrast volume was 100 mL (IQR, 70-150mL), fluoroscopy time was 63.9 minutes (IQR, 49.7-80.4 minutes) and median cumulative air kerma radiation dose was 2630 mGy (IQR, 838-5251 mGy). Thirty-day mortality was 4.8% (n = 34). Access complications occurred in 6.8% (n = 48) and 30-day reintervention in 7% (n = 50; 18 branch related). Follow-up of >30 days was available for 628 patients (88%), with a median follow-up of 19 months (IQR, 8-39 months). Branch-related endoleaks (type Ic/IIIc) were observed in 15 patients (2.6%) and aneurysm growth of >5 mm was observed in 54 (9.5%). Freedom from reintervention at 12 and 24 months was 87.1% (standard error [SE],1.5%) and 79.2% (SE, 2.0%), respectively. Overall target vessel patency at 12 and 24 months was 98.6% (SE, 0.3%) and 96.8% (SE, 0.4%), respectively, and was 97.9% (SE, 0.4%) and 95.3% (SE, 0.8%) for arteries stented from below using the MPDS, respectively.

CONCLUSIONS

The MPDS is safe and effective. Overall benefits include a decrease in contralateral sheath size in the treatment of complex anatomies with favorable results.

Editor's Choice - Quality Assessment of European Society for Vascular Surgery Clinical Practice Guidelines

OBJECTIVE

An increasing number of clinical practice guidelines (CPGs) have emerged over recent years. To have clinical utility, they need to be rigorously developed and scientifically robust. Instruments have been developed to assess the quality of clinical guideline development and reporting. The aim of this study was to evaluate CPGs from the European Society for Vascular Surgery (ESVS) using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) instrument.

METHODS

CPGs published by the ESVS during the period January 2011 to January 2023 were included. Two independent reviewers assessed the guidelines after receiving training in the use and application of the AGREE II instrument. Inter-reviewer reliability was assessed with the intraclass correlation coefficient. Maximum scaled scores were 100. Statistical analysis was performed using SPSS Statistics v.26.

RESULTS

Sixteen guidelines were included in the study. Good inter-reviewer score reliability was found on statistical analysis (> 0.9). The mean ± standard deviation domain scores were 68.1 ± 20.3% for scope and purpose, 57.1 ± 21.1% for stakeholder involvement, 67.8 ± 19.5% for rigour of development, 78.1 ± 20.6% for clarity of presentation, 50.3 ± 15.4% for applicability, 77.6 ± 17.6% for editorial independence, and 69.8 ± 20.1% for overall quality. Stakeholder involvement and applicability have improved in quality over time but are still the lowest scoring domains.

CONCLUSION

Most ESVS clinical guidelines are of high quality and reporting. There is scope for improvement, specifically by addressing the domains of stakeholder involvement and clinical applicability.

Editor's Choice - Estimated Radiation Dose to the Operator During Endovascular Aneurysm Repair

OBJECTIVE

To estimate operator organ doses from fluoroscopically guided infrarenal endovascular aneurysm repair (EVAR) procedures, using the detailed exposure information contained in radiation dose structured reports.

METHODS

Conversion factors relating kerma area product (PKA) to primary operator organ doses were calculated using Monte Carlo methods for 91 beam angles and seven x-ray spectra typical of clinical practice. A computer program was written, which selects the appropriate conversion factor for each exposure listed in a structured report and multiplies it by the respective PKA. This system was used to estimate operator doses for 81 EVAR procedures for which structured reports were available. The impact of different shielding scenarios and variations in operator position was also investigated.

RESULTS

Without any shielding, the median estimated effective dose was 113 μSv (interquartile range [IQR] 71, 252 μSv). The highest median organ doses were for the colon (154 μSv, IQR 81, 343) and stomach (133 μSv, IQR 76, 307). These dose estimates represent all exposures, including fluoroscopy and non-fluoroscopic digital acquisitions. With minimal shielding provided by 0.25 mm of Pb covering the torso and upper legs, the effective dose was reduced by a factor of around 6. With additional shielding from ceiling and table shields, a 25 to 50 fold reduction in dose is achievable. Estimated doses were highest where the primary beam was pointed directly away from the operator.

CONCLUSION

The models suggest that with optimal use of shielding, operator doses can be reduced to levels equivalent to one to two days of natural background exposure and well below statutory dose limits.

The role of multimodal imaging in emergency vascular conditions: The journey from diagnosis to hybrid operating rooms

Multimodal imaging is the incorporation of two or more imaging modalities during the same examination, and it has both diagnostic and treatment applications. The use of image fusion for intraoperative guidance in endovascular interventions is being extended increasingly to the field of vascular surgery, especially in the context of hybrid operating rooms. The aim of this work was to perform a review and narrative synthesis of the available literature in order to report on current applications of multimodal imaging in diagnosis and treatment of emergent vascular conditions. Of 311 records selected in the initial search, 10 articles were included in the present review: 4 cohort studies and 6 case reports. The authors have presented their experience in treating ruptured abdominal aortic aneurysms; aortic dissections; traumas; standard endovascular aortic aneurysm repair, with or without deterioration of renal function; and complex endovascular aortic aneurysm repair, and reported on the long-term clinical results. Although the current literature about multimodal imaging application in emergency vascular conditions is limited, this review highlights the potential of image fusion in hybrid angio-surgical suites, especially for diagnosing and performing treatment in the same operating room, avoiding patient transfer, and allowing procedures with zero or low-dose contrast mean.

Evaluation of the association between silent ischemic lesions and stent design in carotid stenting applications

OBJECTIVE

Minor ischemic events and silent ischemic lesions are more common in carotid stenting than in endarterectomy. These silent ischemic lesions are also associated with stroke risk and cognitive impairment, so it is important to understand the factors that increase the risk and develop strategies to reduce the risk. We aimed to evaluate the association between carotid stent design and silent ischemic lesion development.

METHODS

The files of the patients who underwent carotid stenting between January 2020 and April 2022 were scanned. Patients with diffusion MR images taken within the postoperative 24 h were included in the study, while those undergoing acute stent placement were excluded. The patients were divided into two groups: those with open-cell stents and those with closed-cell stents.

RESULTS

A total of 65 patients, including 39 patients undergoing open-cell stenting and 26 patients undergoing closed-cell stenting, were included in the study. There was no significant difference in demographic data and vascular risk factors between the groups. New ischemic lesions were detected in 29 (74.4%) patients in the open-cell stent group and 10 (38.4%) patients in the closed-cell stent group and were significantly higher in the open-cell group. There was no significant difference between the two groups in terms of major and minor ischemic events and stent restenosis at the 3-month follow-up.

CONCLUSION

The rate of new ischemic lesion development was found to be significantly higher in carotid stent procedures performed with an open-cell Protégé stent than in those performed with a closed-cell Wallstent stent.

A State-of-the-Art Review of Intra-Operative Imaging Modalities Used to Quality Assure Endovascular Aneurysm Repair

Endovascular aortic aneurysm repair (EVAR) is the preferred method for elective abdominal aortic aneurysm (AAA) repair. However, the success of this technique depends greatly on the technologies available. Intra-operative imaging is essential but can come with limitations. More complex interventions lead to longer operating times, fluoroscopy times, and greater contrast doses. A number of intra-operative imaging modalities to quality assure the success of EVAR have been developed. A systematic literature search was performed with separate searches conducted for each imaging modality in the study: computed tomography (CT), digital subtraction angiography (DSA), fusion, ultrasound, intra-operative positioning system (IOPS), and non-contrast imaging. CT was effective at detecting complications but commonly resulted in increased radiation and contrast dose. The effectiveness of DSA can be increased, and radiation exposure reduced, through the use of adjunctive technologies. We found that 2D-3D fusion was non-inferior to 3D-3D and led to reduced radiation and contrast dose. Non-contrast imaging occasionally led to higher doses of radiation. Ultrasound was particularly effective in the detection of type II endoleaks with reduced radiation and contrast use but was often operator dependent. Unfortunately, no papers made it past full text screening for IOPS. All of the imaging techniques discussed have advantages and disadvantages, and clinical context is relevant to guide imaging choice. Fusion and ultrasound in particular show promise for the future.