Modern Image Acquisition System Reduces Radiation Exposure to Patients and Staff During Complex Endovascular Aortic Repair

Prospective evaluation of upper extremity access and total transfemoral approach during fenestrated and branched endovascular repair

OBJECTIVE

Total transfemoral (TF) access has been increasingly used during fenestrated-branched endovascular aortic repair (FB-EVAR). However, it is unclear whether the potential decrease in the risk of cerebrovascular events is offset by increased procedural difficulties and other complications. The aim of this study was to compare outcomes of FB-EVAR using a TF vs upper extremity (UE) approach for target artery incorporation.

METHODS

We analyzed the clinical data of consecutive patients enrolled in a prospective, nonrandomized clinical trial in two centers to investigate the use of FB-EVAR for treatment of complex abdominal aortic aneurysms (CAAA) and thoracoabdominal aortic aneurysms (TAAA) between 2013 and 2022. Patients were classified into TF or UE access group with a subset analysis of patients treated using designs with directional branches. End points were technical success, procedural metrics, 30-day cerebrovascular events defined as stroke or transient ischemic attack, and any major adverse events (MAEs).

RESULTS

There were 541 patients (70% males; mean age, 74 ± 8 years) treated by FB-EVAR with 2107 renal-mesenteric TAs incorporated. TF was used in175 patients (32%) and UE in 366 patients (68%) including 146 (83%) TF and 314 (86%) UE access patients who had four or more TAs incorporated. The use of a TF approach increased from 8% between 2013 and 2017 to 31% between 2018 and 2020 and 96% between 2021 and 2022. Compared with UE access patients, TF access patients were more likely to have CAAAs (37% vs 24%; P = .002) as opposed to TAAAs. Technical success rate was 96% in both groups (P = .96). The use of the TF approach was associated with reduced fluoroscopy time and procedural time (each P < .05). The 30-day mortality rate was 0.6% for TF and 1.4% for UE (P = .67). There was no early cerebrovascular event in the TF group, but the incidence was 2.7% for UE patients (P = .035). The incidence of MAEs was also lower in the TF group (9% vs 18%; P = .006). Among 237 patients treated using devices with directional branches, there were no significant differences in outcomes except for a reduced procedural time for TF compared with UE access patients (P < .001).

CONCLUSIONS

TF access was associated with a decreased incidence of early cerebrovascular events and MAEs compared with UE access for target artery incorporation. Procedural time was decreased in TF access patients irrespective of the type of stent graft design.

Underestimation of Occupational Radiation Exposure During Endovascular Abdominal Aortic Aneurysm Repair

ABSTRACT

During interventional procedures of endovascular abdominal aortic aneurysm repair (EVAR), the dosimeter was conventionally placed on chest facing toward the surgical table, instead of the main source of scatter radiation. Purpose of this study is to evaluate the underestimation of occupational radiation exposure. Phantom experiments were performed in a hybrid operating room equipped with an interventional angiography system. Electric personal dosimeters were placed at the level of eyes, chest, abdomen, and gonad of three positions, representing the principal operator (PO), assistant operator (AO), and sterile nurse (SN). Personal dose equivalent was measured with two different orientations of radiation detection, facing the table and facing the phantom, respectively. In addition to fluoroscopy, the dose produced by digital subtraction angiography was also measured to estimate the radiation exposure of routine EVAR. In this study, staff doses of 26 EVAR cases were also collected in our hospital to correlate the estimated dose. Our results show that the facing-phantom dose normalized by dose area product of patient is significantly higher than the facing-table dose when the latter is regularly seen in clinical practice. This underestimation could be even worse at a more distant position (e.g., AO and SN) as the incident angle of scatter radiation is larger. Besides, the estimated dose is highly correlated with the on-site measured dose (R 2 ~ 0.8) at chest and gonad of the PO.

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.

Exploring radiographers' perceptions and knowledge about patient lead shielding: a cross-sectional study in Greece and Cyprus

The present study aimed to explore radiographers' knowledge, clinical practice and perceptions regarding the use of patient lead shielding in Greece and Cyprus. Qualitative data were analyzed using conceptual content analysis and through the classification of findings into themes and categories. A total of 216 valid responses were received. Most respondents reported not being aware of the patient shielding recommendations issued by the American Association of Physicists in Medicine (67%) or the guidance issued by the British Institute of Radiology (69%). Shielding-related training was generally not provided by radiography departments (74%). Most of them (85%) reported that they need specific guidance on lead shielding practices. Also, 82% of the respondents said that lead shielding should continue to be used outside the pelvic area when imaging pregnant patients. Pediatric patients are the most common patient category to which lead shielding was applied. Significant gaps in relevant training have been identified among radiographers in Greece and Cyprus, highlighting the need for new protocols and provision of adequate training on lead shielding practices. Radiography departments should invest in appropriate shielding equipment and adequately train their staff.

Fiber Optic RealShape imaging using upper extremity and transfemoral access for fenestrated-branched endovascular aortic aneurysm repair

We report our initial experience using Fiber Optic RealShape (FORS), an innovative real-time three-dimensional visualization technology that uses light instead of radiation, to achieve upper extremity (UE) access during fenestrated/branched endovascular aortic aneurysm repair (FBEVAR). An 89-year-old male patient with a type III thoracoabdominal aortic aneurysm, unfit for open aortic repair, underwent FBEVAR. Dual fluoroscopy, intravascular ultrasound, and three-dimensional fusion overlay were used, in addition to FORS. All target artery catheterizations were successfully accomplished using FORS, from UE access, without radiation. Our experience demonstrates that FBEVAR with FORS using UE access can be used for target artery catheterization without radiation.

Fiber Optic RealShape (FORS) Technology for Endovascular Navigation in Severe Tortuous Vessels

PURPOSE

The purpose of this study was to describe the use of a wire and catheters embedded with optical fiber (Fiber Optic RealShape [FORS]) to catheterize tortuous target vessels avoiding radiation.

TECHNIQUE

A virtual biplane vies was simulated coupling traditional x-ray system, preoperative CT scan, and FORS system to treat an isolated hypogastric aneurysm. Despite the complex anatomy, catheterization of all target vessels was possible in 12 minutes with 19 seconds of fluoroscopy time (Radiation Exposure 3.8 mGy×cm²). A minimal invasive endovascular exclusion of the aneurysm was achieved through selective coil-embolization of the iliolumbar artery and implantation of balloon expandable covered stents, thus preserving the perfusion of the superior gluteal artery.

CONCLUSION

FORS guidance allowed catheterization of a target vessel with challenging anatomy with a low radiation exposure.

A Single Center Review of a Total Transfemoral Approach to Upper Extremity Access in Branched and Fenestrated Physician Modified Endografts

BACKGROUND

Aortic aneurysms are normally treated by an endovascular approach. Due to the lack of devices and increasing experience, there is a growing number of complex aneurysms undergoing repair by physician modified endografts (PMEGs). Previously, our practice was to target visceral vessels exclusively through upper extremity access. We have since then shifted to an all transfemoral approach when possible. This study aims to show the operative benefits of transfemoral only approaches.

METHODS

Patients who underwent a PMEG at a tertiary center between 2015 and 2020 were included. Patients were stratified into 2 groups based on branched vessel approach-transfemoral only versus axillary or composite (axillary and femoral). Forty-one patients had a pararenal or type IV thoracoabdominal aortic aneurysm (TAAA) and 15 patients had more complex TAAA. Primary outcomes were operative time, radiation exposure, fluoroscopy time, contrast, and blood loss. Secondary outcomes were 30-day mortality and major adverse events. Linear regression models were used to evaluate the association between approach type and the main outcomes.

RESULTS

Fifty-six patients were included with 48% (n = 27) in the transfemoral group and 52% (n = 29) in the axillary/composite group. Baseline characteristics were similar between the groups. Intraoperative outcomes revealed significant increase in the average operative time (418 vs. 246 min, P < 0.001), in radiation exposure (2,755 vs. 1,740 mGy, P = 0.03), in fluoroscopy time (108 vs. 74 min, P = 0.01) and in blood loss (579 vs. 202 cc, P = 0.002) in the axillary/composite group compared to the transfemoral group. There was no significant difference in 30-day mortality or major adverse events including stroke.

CONCLUSIONS

This study shows a transfemoral approach to complex endovascular aortic aneurysm repair as opposed to axillary/composite approach has decreased operative time, radiation exposure, and fluoroscopy time and no significant differences in 30-day mortality or major adverse events. When treating complex aneurysms, improving efficiency is important to minimize morbidity to patients and operators.

Iliac branch device to treat type IB endoleak with a brachial access or an "up-and-over" transfemoral technique

PURPOSE

This study aimed to review the results of secondary IBD (iliac branch device) implantation in patients with type IB endoleak after prior fenestrated and/or branched or infrarenal endovascular aortic repair (F/B-EVAR or EVAR), using either brachial access or an "up-and-over" transfemoral technique.

METHODS

A retrospective single centre analysis was conducted between Jan 2016 and Oct 2021 including consecutive patients that underwent IBD to correct a type IB endoleak after prior EVAR or F/B-EVAR. Groups were defined by arterial access which was either brachial (group 1) or transfemoral (group 2). All IBD implanted were manufactured by Cook Medical (INC, Bloomington, IN, USA). Demographics, anatomical features, technical success, and 30-day major adverse events (MAE) were recorded according to the current SVS standards. Survival curves according to Kaplan-Meier were calculated. Branch instability was a composite endpoint of any IIA branch-related complication or reintervention indicated to treat endoleak, kink, disconnection, stenosis, occlusion or rupture.

RESULTS

Overall, 28 patients (93% male, median age 74 years) receiving 32 IBDs were included, with 14 patients in each group. Prior endovascular aortic repairs were 23 EVAR and 5 F/B-EVAR, with time from initial repair being 58 months [48, 70]. Median pre-IBD maximal aneurysm diameter was 63.5 mm [59.0, 78.0]. Patients' baseline characteristics were similar in both groups except for pulmonary status. All procedures were performed in a hybrid operative room. Median total operating time, fluoroscopy time and dose area product were 120 min [86, 167], 23 min [15, 32] and 54 Gy.cm2 [40, 62], respectively. Total operating time was shorter in group 2 (p=0.006). Technical success rate was 100% and no early death reported. One 30-day MAE occurred including a medically treated colonic ischemia (group 2). Aortic-related secondary interventions were required in 7 patients (5 in group 1 and 2 in group 2) including 3 surgical explantations. Median follow-up was 31 months [24, 42] and 6 months [3, 10] in group 1 and 2, respectively. In group 1, 2-year freedom from aortic-related secondary intervention and IIA branch instability were 84.6% [67.1-100] and 92.3% [78.9-100], respectively. In group 2, 6-month freedom from aortic-related secondary intervention and IIA branch instability were 87.5% [67.3-100] and 91.7% [77.3-100], respectively.

CONCLUSION

The secondary implantation of IBD to correct distal type I endoleak of previous aortic stent-graft is safe with a high technical success rate. The "up-and-over" technique could be considered as an alternative to the brachial access in patients with suitable anatomy.

Impact of dose reducing software on patient and staff temple dose during fluoroscopically guided pacemaker insertion, closure devices implantation and coronary angiography procedures

The aim of this study is to investigate the effectiveness of dose reducing software (ClarityIQ) on patient and staff dose during fluoroscopically guided cardiac procedures. Dose measurements were collected in a room without dose reducing software (n = 157) and compared with similar procedures performed in two rooms with the software (n = 1141). Procedures included diagnostic coronary angiography, percutaneous coronary intervention, deployment of cardiac closure devices (for occlusion of atrial septal defect, patent foramen ovale, and atrial appendage) and insertion of permanent pacemakers. The dose reducing software was found to be effective in reducing patient and staff dose by approximately 50%. This study has added to the limited literature reporting on the capability of dose reducing software to decrease radiation exposure during the implantation of cardiac closure devices, as well as demonstrating a reduction in dose to the cardiologist and nursing staff. Administrators should ensure timely upgrades to angiographic equipment to safeguard patients and staff against the potentially adverse effects of radiation exposure. Regardless of the use of dose reducing software, the mean occupational dose during closure devices was in descending order scout > scrub > cardiologist. Scrub nurse dose was found to be higher than the cardiologist during closure devices (0.98/0.26 μSv) and diagnostic coronary angiograms (1.51/0.82 μSv). Nursing staff should be aware that their levels of radiation dose during some cardiac procedures may come close to or even exceed that of the cardiologist.

Comparison of transfemoral versus upper extremity access to antegrade branches in branched endovascular aortic repair

OBJECTIVE

We studied the outcomes of transfemoral access (TFA) vs upper extremity access (UEA) for branched endovascular aortic repair (BEVAR).

METHODS

From January 2016 to October 2019, 152 consecutive patients underwent BEVAR under general anesthesia at a single institution. In 2018, an alternative approach to the antegrade branches using TFA compared with conventional UEA was introduced. The cohort was divided into TFA and UEA groups according to the access approach. The end points were technical success, adverse events (including perioperative stroke/transient ischemic attack), access complications, operation time, and radiation exposure.

RESULTS

The TFA group included 60 patients (63% male; median age, 71 years; interquartile range [IQR], 65-76 years). The UEA group included 92 patients (67% male; median age, 73 years; IQR, 66-78 years). The number of target vessels (TVs) was similar in both groups (median, 4.0 TVs per procedure; range, 1-7 TVs for both). Technical success was greater in the TFA group (60 of 60 patients; 209 of 209 TVs) than in the UEA group (87 of 92 patients; 334 of 346 TVs; P < .01). The fluoroscopy time (median, 69 minutes; IQR, 48-87 minutes; vs 88 minutes; IQR, 65-104 minutes; P = .39) and contrast agent volume (median, 141 mL; IQR, 123-165 mL; vs median, 130 mL; IQR, 101-157 mL; P = .34) were similar in both groups. The radiation exposure (221 Gy × cm²; IQR, 138-406 Gy × cm²; vs median, 255 Gy × cm²; IQR, 148-425 Gy × cm²; P = .05) was lower and the operation time (median, 300 minutes; IQR, 240-356 minutes; vs median, 364 minutes; IQR, 290-475 minutes; P = .01) was shorter in the TFA group. Brachial access complications (0 of 60 vs 3 of 92 patients) and perioperative strokes/transient ischemic attacks (0 of 60 vs 8 of 92 patients) only occurred in the UEA group (P = .018).

CONCLUSIONS

The use of TFA to catheterize antegrade branches was associated with a lower rate of complications in the present study and has become our preferred approach for BEVAR.