Evaluation of radiation during EVAR performed on a mobile C-arm

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.

Impact of the Endonaut® Angio-Navigation System on Radiation Exposure in Endovascular Aortic Repair Performed with Mobile C-Arms

BACKGROUND

Fusion imaging systems have proved to reduce radiation exposure mostly in hybrid rooms but reports with mobile C-arms are few. The aim of this study was to analyze the impact of the Endonaut navigation system on radiation exposure in endovascular aneurysm repair (EVAR) performed with mobile C-arms.

METHODS

All patients undergoing EVAR and/or iliac branched devices implantation between January 2016 and August 2022 were included. All procedures were performed with a mobile C-arm (Siemens Avantic or GE Elite until March 2018, Siemens Cios Alpha thereafter). The Endonaut navigation system has been used since January 2021. Two groups were, therefore, compared: before (control group [CGr]) and after the use of Endonaut. Radiation data including Dose Area Product (DAP) values, Air Kerma (AK) and fluoroscopy time (FT) were collected retrospectively.

RESULTS

Overall, 153 patients were included: CGr, n = 121; Endonaut group (EnGr), n = 32. No significant difference was found between the 2 groups regarding demographic data. DAP values were significantly lower in the EnGr (38 Gy cm2 ± 24) vs. the CGr (76 Gy cm2 ± 51) (P < 0.05) despite a significantly higher number of complex procedures such as iliac branched devices (P < 0.05). AK values were not significantly different between the EnGr and the CGr (196 mGy ±114 vs. 209 mGy ±138) as well as FT (33 minutes ±18 vs. 33 minutes ±16). Technical success was 97% (31/32) in the EnGr vs. 96% (116/121) in the CGr (P = 0.79). The volume of contrast media was significantly lower in the EnGr (94 cc ± 41) vs. the CGr (143 cc ± 66) (P < 0.05).

CONCLUSIONS

In this study, the use of the Endonaut angio-navigation system when performing EVAR with mobile C-arms led to a radiation dose reduction without compromising technical success or procedural time.

Low-dose pulsed vs standard pulsed fluoroscopy during ERCP to reduce radiation without change in image quality: Prospective randomized study

Background and study aims Endoscopic retrograde cholangiopancreatography (ERCP) poses the risk of radiation exposure (RE) to patients and staff and increases the risk of adverse biological effects such as cataracts, sterility, and cancer. Newer fluoroscopy equipment (C-Arm) provides options to limit radiation in the form of lower radiation dose and frame rate or time-limited "pulsed" settings. However, the impact of lower settings on image quality has not been assessed, and no standard protocol exists for fluoroscopy settings used during ERCP. Patients and methods This was a single-center, double-blind, prospective randomized study of consecutive adult patients undergoing standard-of-care ERCP at a tertiary academic medical center. Patients were randomized into two groups: 1) standard-dose pulsed and 2) low-dose pulsed. Pulsed mode (8 fps) was defined as x-ray exposure either in the manufacturer standard-dose or low-dose settings limited to 3 seconds each time the foot-operated switch was depressed. Results Seventy-eight patients undergoing ERCP were enrolled and randomized. No difference in age, gender, or body mass index was found between the two groups. No significant difference in image quality was found between standard-dose and low-dose fluoroscopy P = 0.925). The low-dose group was exposed to significantly less radiation when compared with standard-dose P < 0.05). Fluoroscopy time (minutes) was similar in both groups (2.0 vs 1.9), further suggesting that group assignment had no impact on image quality or procedure time. Conclusions Low-dose pulsed fluoroscopy is a reliable method that substantially reduces radiation without compromising image quality or affecting procedure or fluoroscopy times. This underscores the need for standardization in ERCP fluoroscopy settings to limit radiation exposure.

A MODEL FOR EVALUATING THE USE OF IMAGING IN IMAGE-GUIDED INTERVENTIONAL PROCEDURES-POSSIBLE IMPLICATIONS ON OPTIMISATION OF RADIATION PROTECTION

The present study focuses on introducing the concept of optimisation and proposing a model, including evaluation of image quality, to be used in the clinical routines where image-guided intervention is being performed. The overall aim of the study was to develop a model for evaluating the use of imaging in X-ray-guided interventional procedures and its possible implications on optimisation of radiation protection. In the search for an adequate evaluation model, data from endovascular interventions of the aorta (EVAR procedures) were used. The procedure was schematically described in steps. Every imaging event was connected to the steps in the medical procedure and was also described with the purpose of the imaging event. Available technical, as well as procedural parameters, were studied and analysed. Data were collected from the X-ray equipment for 70 EVAR procedures and, out of these, 12 procedures were randomly selected to be recorded on video to understand the procedure better. It was possible to describe the EVAR procedures in a general way with explanations of the clinical purpose connected to each imaging event. Possible quality parameters of the procedure were identified for the imaging events (radiation dose, image quality). The model method still needs to be refined and will then be applied to clinical data and to other clinical procedures to test the validity.

Hybrid operating room applications in the increasingly complex endovascular era: the trump card of modern vascular surgery

Hybrid operating room represents nowadays an important tool in the management of a constantly increasing number of complex surgical procedures which necessitate appropriate settings in order to be performed safely. We herein present the peculiarities and applications of such a versatile operating environment which is capable of guaranteeing the best performances in terms of equipment and imaging tools respecting the standards of asepsis that a simple angiographic room could not offer. In particular, we focus on its relevance in the field of complex vascular pathology, and on the importance of setting an appropriate management process in order to make the most of its potentialities without sacrificing the not negligible costs connected to it.

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.

Patient radiation exposure from embolo-sclerotherapy of peripheral vascular malformations

OBJECTIVE

Embolo-sclerotherapy (EST) is the mainstay therapy for peripheral vascular malformations that involves the exposure of patients to ionizing radiation. We analyzed the radiation exposure to patients from EST of peripheral vascular malformations during a 5-year period in a single specialist center.

METHODS

All patients who had undergone EST at a single specialist center for peripheral vascular malformations from January 1, 2013 to January 8, 2018 were identified from a prospectively collected database. Data collection included basic demographics, procedure date, anatomic site, type of vascular malformations, and procedural details. Radiation exposure, measured as the dose-area product (DAP) and fluoroscopy time, of all patients who had undergone EST during the study period were retrospectively reviewed. Statistical analysis was performed using the Mann-Whitney U and Kruskal-Wallis tests for comparison between subgroups. P < .05 was considered statistically significant.

RESULTS

A total of 237 patients (median age, 30 years; range, 1-73 years) had undergone 419 EST sessions during the study period. Of the 237 patients, 61 (25.7%) had had arteriovenous malformations (AVMs) and had undergone 140 EST sessions (33.4%) and 176 (74.3%) had had venous and lymphatic malformations and had undergone 279 EST sessions (66.6%). Patients with AVMs had undergone a median of 2 procedures (range, 1-13) compared with a median of 1 (range, 1-6) for venous and lymphatic malformations within the study period. The median DAP for the single and cumulative EST for peripheral vascular malformations was 1.26 Gycm² (range, 0.00-698.36 Gycm²) and 1.91 Gycm² (range, 0.00-1300.24 Gycm²), respectively. The median fluoroscopy time for single and cumulative EST was 19 seconds (range, 1-3846 seconds) and 30 seconds (range, 1-5843 seconds), respectively. Significantly greater patient radiation exposure, in DAP and fluoroscopy time, was measured for single and cumulative EST for AVMs compared with venous and lymphatic malformations (P < .01 for both; Mann-Whitney U test). A significant difference in DAP but not fluoroscopy time was found when the anatomic areas of vascular malformations were compared.

CONCLUSIONS

Patient radiation exposure for EST for peripheral vascular malformations, measured in DAP and fluoroscopy time, appeared to be generally less than that reported for endovascular arterial and deep venous interventions. However, some patients with peripheral vascular malformations received relatively high radiation doses. Further studies to investigate the risk factors and long-term side effects of radiation exposure in these patients and strategies to reduce these are required.

Patient radiation dose from x-ray guided endovascular aneurysm repair: a Monte Carlo approach using voxel phantoms and detailed exposure information

Endovascular aneurysm repair (EVAR) is a well-established minimally invasive technique that relies on x-ray guidance to introduce a stent through the femoral artery and manipulate it into place. The aim of this study was to estimate patient organ and effective doses from EVAR procedures using anatomically realistic computational phantoms and detailed exposure information from radiation dose structured reports (RDSR). Methods: Lookup tables of conversion factors relating kerma area product (P_KA) to organ doses for 49 different beam angles were produced using Monte Carlo simulations (MCNPX2.7) with International Commission on Radiological Protection (ICRP) adult male and female voxel phantoms for EVAR procedures of varying complexity (infra-renal, fenestrated/branched and thoracic EVAR). Beam angle specific correction factors were calculated to adjust doses according to x-ray energy. A MATLAB function was written to find the appropriate conversion factor in the lookup table for each exposure described in the RDSR, perform energy corrections and multiply by the respective exposure P_KA. Using this approach, organ doses were estimated for 183 EVAR procedures in which RDSRs were available. A number of simplified dose estimation methodologies were also investigated for situations in which RDSR data are not available. Results: Mean estimated bone marrow doses were 57 (range: 2-247), 86 (2-328) and 54 (8-250) mGy for infra-renal, fenestrated/branched and thoracic EVAR, respectively. Respective effective doses were 27 (1-208), 54 (1-180) and 37 (5-167) mSv. Dose estimates using non-individualised, average conversion factors, along with those produced using the alternative Monte Carlo code PCXMC, yielded reasonably similar results overall, though variation for individual procedures could exceed 100% for some organs. In conclusion, radiation doses from x-ray guided endovascular aneurysm repairs are potentially high, though this must be placed in the context of the life sparing nature and high success rate for this procedure.

Editor's Choice - Comprehensive Literature Review of Radiation Levels During Endovascular Aortic Repair in Cathlabs and Operating Theatres

OBJECTIVE

Occupational exposure is a growing concern among the endovascular specialist community. Several types of imaging equipment are available, such as mobile C arms or hybrid rooms, and some have been shown to deliver higher levels of radiation. A literature review was conducted to identify studies reporting dose data during standard (EVAR) and complex abdominal aortic endovascular repair (fenestrated/branched EVAR [F/BEVAR]).

METHODS

A search of the MEDLINE and the Cochrane databases was performed by two independent investigators using the medical subject heading terms "aortic aneurysms", "radiation", and "humans" over a search period of 10 years. Studies with full text available in English and reporting radiation data independently from the imaging equipment type were included. Experimental studies were excluded.

RESULTS

The lowest dose-area product levels during EVAR and F/BEVAR were identified in hybrid rooms, while the highest were with fixed systems. When adherence to the as low as reasonably achievable principles was stipulated by the authors, dose reports tended to be among the lowest. Several studies, especially of F/BEVAR, report concerning levels of radiation for both patients and staff.

CONCLUSION

Modern imaging equipment type, team involvement with radiation management, and the support of recent imaging technologies such as fusion help to reduce the dose delivered during standard and complex EVAR. Investment in modern imaging technology should be considered in every centre providing endovascular management of aortic aneurysms.

Dose reduction using digital fluoroscopy versus digital subtraction angiography in endovascular aneurysm repair: A prospective randomized trial

OBJECTIVE

Endovascular aneurysm repair (EVAR) can result in high radiation dose to patients and operators. This prospective randomized study aimed to assess whether patient radiation dose sustained during EVAR could be decreased by predominantly using digital fluoroscopy (DF) vs the standard technique using digital subtraction angiography (DSA).

METHODS

Between February 2011 and June 2017, patients with EVAR of infrarenal abdominal aortic aneurysms were prospectively enrolled and randomly assigned to a standard treatment DSA cohort or a DF cohort in which two or fewer DSA acquisitions were allowed for confirmatory imaging. Primary end points included dose-area product (DAP) and cumulative air kerma. Secondary end points included technical success and conversion to DSA standard treatment (if DF was inadequate for visualization).

RESULTS

For all 43 patients enrolled (26 in the DF cohort, 17 in the DSA cohort), technical success was 100%. Of the 26 DF patients, 5 (19%) required conversion to the DSA cohort. In an intention-to-treat analysis, mean DAP was significantly lower in the DF cohort than in the DSA cohort (132 vs 174 Gy·cm²; P = .04). When patients were separated by number of DSA acquisitions (two or fewer vs three or more), mean DAP decreased 41% (109 vs 185 Gy·cm²; P = .005) and cumulative air kerma decreased 40% (578 vs 964 mGy; P = .004).

CONCLUSIONS

In most patients (81%), DF or limited DSA was adequate for visualization during EVAR. In both intention-to-treat DF and limited-DSA cohorts, mean DAP was significantly decreased. If image quality allows, a DF-only or limited-DSA approach to EVAR decreases radiation dose.

[Artificial intelligence in vascular surgery and vascular medicine]

New digital technologies will also gain in importance in vascular surgery. There is a wide field of potential applications. Simulation-based training of endovascular procedures can lead to improvement in procedure-specific parameters and reduce fluoroscopy and procedural times. The use of intraoperative image-guided navigation and robotics also enables a reduction of the radiation dose. Artificial intelligence can be used for risk stratification and individualization of treatment approaches. Health apps can be used to improve the follow-up care of patients.

Radiation exposure of dogs and cats undergoing fluoroscopic procedures and for operators performing those procedures

OBJECTIVE

To evaluate radiation exposure of dogs and cats undergoing procedures requiring intraoperative fluoroscopy and for operators performing those procedures.

SAMPLE

360 fluoroscopic procedures performed at 2 academic institutions between 2012 and 2015.

PROCEDURES

Fluoroscopic procedures were classified as vascular, urinary, respiratory, cardiac, gastrointestinal, and orthopedic. Fluoroscopy operators were classified as interventional radiology-trained clinicians, orthopedic surgeons, soft tissue surgeons, internists, and cardiologists. Total radiation exposure in milligrays and total fluoroscopy time in minutes were obtained from dose reports for 4 C-arm units. Kruskal-Wallis equality of populations rank tests and Dunn pairwise comparisons were used to compare differences in time and exposure among procedures and operators.

RESULTS

Fluoroscopy time (median, 35.80 minutes; range, 0.60 to 84.70 minutes) was significantly greater and radiation exposure (median, 137.00 mGy; range, 3.00 to 617.51 mGy) was significantly higher for vascular procedures than for other procedures. Median total radiation exposure was significantly higher for procedures performed by interventional radiology-trained clinicians (16.10 mGy; range, 0.44 to 617.50 mGy), cardiologists (25.82 mGy; range, 0.33 to 287.45 mGy), and internists (25.24 mGy; range, 3.58 to 185.79 mGy).

CONCLUSIONS AND CLINICAL RELEVANCE

Vascular fluoroscopic procedures were associated with significantly longer fluoroscopy time and higher radiation exposure than were other evaluated fluoroscopic procedures. Future studies should focus on quantitative radiation monitoring for patients and operators, importance of operator training, intraoperative safety measures, and protocols for postoperative monitoring of patients.

Radiation exposure in an endovascular aortic aneurysm repair program after introduction of a hybrid operating theater

BACKGROUND

A hybrid operating theater (HOT) enables optimal image quality, improved ergonomics, and excellent sterility for complex endovascular and hybrid procedures. We hypothesize that the commissioning of a new HOT involves a learning curve. It is unclear how steep the learning curve of these advanced HOTs is. The main purpose of this research was to evaluate radiation exposure parameters in a new HOT for a team of vascular surgeons experienced with infrarenal endovascular aneurysm repair (EVAR) procedures in a conventional operating room with a mobile C-arm. In addition, a comparison of the dose-area product (DAP) achieved in this study and in the literature was made.

METHODS

Before commissioning of the HOT, four vascular surgeons completed a comprehensive HOT training program. From the commissioning of the HOT, clinical and procedural data for all consecutive acute and elective patients treated with EVAR were retrospectively collected for a period of 18 months (January 2016-June 2017). A literature review was conducted of the dose-area product in EVAR procedures performed with a dedicated fixed system or mobile C-arm to analyze how this study performed compared with the literature.

RESULTS

In the 18-month study period, 77 patients were treated with EVAR (59 electively and 18 acutely), from whom the data were obtained. There was no significant change in radiation exposure parameters over time. From the commissioning of the HOT, EVAR procedures were performed with radiation exposure parameters similar to those of studies found in experienced vascular centers using fixed systems.

CONCLUSIONS

Concerning radiation exposure parameters, the commissioning of a new HOT was not accompanied by a learning curve. Radiation exposure parameters achieved in this study were similar to those of studies from experienced and dedicated vascular centers.

Endovascular Intervention with a Mobile C-Arm in the Operating Room

Mobile C-arm fluoroscopic X-ray systems are used for various diagnostic imaging and minimally invasive endovascular procedures. One of the greatest advantages of a mobile C-arm is its ability to move around the patient. The purpose of this study was to address the optimal setting of the mobile C-arm and the operating table, as well as the proper position of the operator and assistants for each procedure. In addition, methods to minimize radiation exposure to the operator and medical staff are described. Both the optimal setting and the proper position were classified by 5 types. These include the setting for aortic and inferior vena caval procedures (type I); left lower extremity (LE) intervention with an up-and-over technique (type II); right LE intervention with up-and-over technique, or bilateral LE vascular intervention with antegrade access (type III); arteriovenous fistula/graft intervention (type IV); and central vein catheterization (type V).

Correlations Between Branch Vessel Catheterization and Procedural Complexity in Fenestrated and Branched Endovascular Aneurysm Repair

Introduction:

The use of fenestrated and branched endovascular technologies in complex aortic aneurysm repair (F/BEVAR) is increasing, with a trend toward using longer sealing zones and incorporating more target vessels. Successful aneurysm exclusion and prevention of long-term treatment failure need to be balanced against the increased complexity of more extensive procedures. The aim of this study was to analyze relationships between the number of catheterized vessels and multiple operative variables as a means for evaluating procedural complexity.

Methods:

Operative data from consecutive F/BEVAR procedures performed at a single center from 2012 to 2015 were analyzed. An equal number of EVAR procedures, randomly selected, from this period were also analyzed. Only intact aneurysms were included. Complex aneurysms were grouped based on the required number of target vessel catheterization. Ten procedural variables, categorized as perioperative, postoperative, and radiologic-related, were compared. Pearson correlation analysis and regression analysis were performed. The correlation coefficients, r, were classified using Cohen boundaries, r ≥ 0.5 indicating a strong relationship.

Results:

There were 63 EVAR, 40 FEVAR, and 22 BEVAR procedures. There was no significant difference in patient comorbidities between conventional EVAR and complex procedure groups. The complex procedures included 23 two-vessel, 20 three-vessel, and 19 four-vessel catheterizations. Strong linear relationships between the number of branch vessel catheterizations and the following variables were identified: accumulated skin dose ( r = .504), contrast volume ( r = .652), fluoroscopy duration ( r = .598), number of angiography series ( r = .650), anesthesiology duration ( r = .742), procedure duration ( r = .554), and total length of stay ( r = .533).

Conclusion:

The complexity of FEVAR and BEVAR procedures reveals strong correlations between multiple peri- and postoperative variables. These exposures and risks should be borne in mind when considering treatment of complex abdominal aortic aneurysms as well as long-term clinical outcomes.

Optimizing imaging and reducing radiation exposure during complex aortic endovascular procedures

Improvements in endovascular technologies and development of custom-made fenestrated and branched endografts currently allow clinicians to treat complex aortic lesions such as thoraco-abdominal and aortic arch aneurysms once treatable with open repair only. These advances are leading to an increase in the complexity of endovascular procedures which can cause long operation times and high levels of radiation exposure. This in turn places pressure on the vascular surgery community to display more superior interventional skills and radiological practices. Advanced imaging technology in this context represents a strong pillar in the treatment toolbox for delivering the best care at the lowest risk level. Delivering the best patient care while managing the radiation and iodine contrast media risks, especially in frail and renal impaired populations, is the challenge aortic surgeons are facing. Modern hybrid rooms are equipped with a wide range of new imaging applications such as fusion imaging and cone-beam computed tomography (CBCT). If these technologies contribute to reducing radiation, they can be complex and intimidating to master. The aim of this review is to discuss the fundamentals of good radiological practices and to describe the various imaging tools available to the aortic surgeon, both those available today and those we anticipate will be available in the near future, from equipment to software, to perform safe and efficient complex endovascular procedures.

Interventional Equipment and Radiation Safety

Interventional radiology in veterinary medicine was adapted from techniques developed in human medicine, and has a variety of applications to treat disease in multiple body systems. Fluoroscopy is required for almost all interventional procedures, requiring knowledge of proper safety techniques for working with ionizing radiation. There are a wide variety of catheters, wires, sheaths, stents, and embolics used in veterinary medicine. Familiarity with their indications and sizing compatibility is essential for procedural success.

Endovascular treatment of para-anastomotic aneurysms after open abdominal aortic surgery

INTRODUCTION

The repair of long-term complications of open abdominal aortic repair such as para-anastomotic aneurysm (PAA) and pseudoaneurysm (PSA) is very challenging. The aim of this study was to assess the outcomes of endovascular repair of PAA/PSA after previous open aortic surgery for aneurismal or occlusive disease.

EVIDENCE ACQUISITION

A systematic review was undertaken; a search was performed (PRISMA) in MEDLINE, CENTRAL, Cochrane databases and key references of all studies of endovascular treatment of PAA/PSA after open aortic surgery.

EVIDENCE SYNTHESIS

Eighteen studies included totally 433 patients (86.3% males) with mean age of 71±2.5 years were identified. Most of the patients were asymptomatic (76%) and diagnosed with PAA (60.5%), while 81.6% had history of open aortic reconstruction for aneurismal disease. The mean diameter of para-anastomotic aneurysms was 59.7 mm (from 23 mm to 110 mm) and the mean duration until their diagnosis was 10±2 years. Standard bifurcated (23.7%), fenestrated (23.4%) and aorto-uni-iliac stent-grafts (16.3%) were mostly used. The technical success rate was 97.8% (391/400) with 1.4% (6/433) 30 day-mortality rate and mean hospital stay of 6±3 days. The mean 1- and 2- year survival rate was 87.8% and 78.8%, respectively. The follow-up ranged from 9 to 43 months, with presenting complications such as endoleak type I (24/378; 6.3%), type II (15/354; 4.3%), type III (3/378;0.8%), migration (4/378; 1%) and limb occlusion (5/310;1.6%). Additionally, 5.7% (19/332) of the patients underwent open conversion, while the total re-intervention rate was 11.4% (39/340; time of reintervention ranged from 7 to 30 months). In cases in which a stent was used for splanchnic vessels (renal artery: 188, superior mesenteric artery: 98, celiac artery: 64), the primary patency rate was 97.4% (341/350).

CONCLUSIONS

Endovascular treatment of PAAs and PSAs after previous open aortic surgery is a feasible and efficient option with high technical success rate, low 30-day mortality and good mid-term outcomes.

Radiation Exposure in Endovascular Infra-Renal Aortic Aneurysm Repair and Factors that Influence It

Objective

The endovascular repair of aortic abdominal aneurysms exposes the patients and surgical team to ionizing radiation with risk of direct tissue damage and induction of gene mutation. This study aims to describe our standard of radiation exposure in endovascular aortic aneurysm repair and the factors that influence it.

Methods

Retrospective analysis of a prospective database of patients with abdominal infra-renal aortic aneurysms submitted to endovascular repair. This study evaluated the radiation doses (dose area product (DAP)), fluoroscopy durations and their relationships to the patients, aneurysms, and stent-graft characteristics.

Results

This study included 127 patients with a mean age of 73 years. The mean DAP was 4.8 mGy.m², and the fluoroscopy time was 21.8 minutes. Aortic bilateral iliac aneurysms, higher body mass index, aneurysms with diameters larger than 60 mm, necks with diameters larger than 28 mm, common iliac arteries with diameters larger than 20 mm, and neck angulations superior to 50 degrees were associated with an increased radiation dose. The number of anatomic risk factors present was associated with increased radiation exposure and fluoroscopy time, regardless of the anatomical risk factors.

Conclusion

The radiation exposure during endovascular aortic aneurysm repair is significant (mean DAP 4.8 mGy.m²) with potential hazards to the surgical team and the patients. The anatomical characteristics of the aneurysm, patient characteristics, and the procedure's technical difficulty were all related to increased radiation exposure during endovascular aortic aneurysm repair procedures. Approximately 40% of radiation exposure can be explained by body mass index, neck angulation, aneurysm diameter, neck diameter, and aneurysm type.

Radiation-Induced DNA Damage in Operators Performing Endovascular Aortic Repair

Supplemental Digital Content is available in the text.

Background:

Radiation exposure during fluoroscopically guided interventions such as endovascular aortic repair (EVAR) is a growing concern for operators. This study aimed to measure DNA damage/repair markers in operators perfoming EVAR.

Methods:

Expression of the DNA damage/repair marker, γ-H2AX and DNA damage response marker, phosphorylated ataxia telangiectasia mutated (pATM), were quantified in circulating lymphocytes in operators during the peri-operative period of endovascular (infrarenal, branched, and fenestrated) and open aortic repair using flow cytometry. These markers were separately measured in the same operators but this time wearing leg lead shielding in addition to upper body protection and compared with those operating with unprotected legs. Susceptibility to radiation damage was determined by irradiating operators’ blood in vitro.

Results:

γ-H2AX and pATM levels increased significantly in operators immediately after branched endovascular aortic repair/fenestrated endovascular aortic repair (P<0.0003 for both). Only pATM levels increased after infrarenal endovascular aortic repair (P<0.04). Expression of both markers fell to baseline in operators after 24 hours (P<0.003 for both). There was no change in γ-H2AX or pATM expression after open repair. Leg protection abrogated γ-H2AX and pATM response after branched endovascular aortic repair/fenestrated endovascular aortic repair. The expression of γ-H2AX varied significantly when operators’ blood was exposed to the same radiation dose in vitro (P<0.0001).

Conclusions:

This is the first study to detect an acute DNA damage response in operators performing fluoroscopically guided aortic procedures and highlights the protective effect of leg shielding. Defining the relationship between this response and cancer risk may better inform safe levels of chronic low-dose radiation exposure.

Investigation of reference levels and radiation dose associated with abdominal EVAR (endovascular aneurysm repair) procedures across several European Centres

OBJECTIVES

Endovascular aneurysm repair (EVAR) is considered the treatment of choice for abdominal aortic aneurysms with suitable anatomy. In order to improve radiation safety, European Directive (2013/59) requires member states to implement diagnostic reference levels (DRLs) in radio-diagnostic and interventional procedures. This study aimed to determine local DRLs for EVAR across five European centres and identify an interim European DRL, which currently remains unestablished.

METHODS

Retrospective data was collected for 180 standard EVARs performed between January 2014 and July 2015 from five specialist centres in Ireland (n=2) and Italy (n=3). Data capture included: air kerma-area product (P_KA), total air kerma at the reference point (K_a,r), fluoroscopic time (FT), number of acquisitions, frame rate of acquisition, type of acquisition, patient height, weight, and gender.

RESULTS

The mean values for each site A, B, C, D, and E were: P_KAs of 4343 ± 994 μGym², 18,200 ± 2141 μGym², 11,423 ± 1390 μGym², 7796 ± 704 μGym², 31,897 ± 5798 μGym²; FTs of 816 ± 92 s, 950 ± 150 s, 708 ± 70 s, 972 ± 61 s, 827 ± 118 s; and number of acquisitions of 6.72 ± 0.56, 10.38 ± 1.54, 4.74 ± 0.19, 5.64 ± 0.36, 7.28 ± 0.65, respectively. The overall pooled 75th percentile P_KA was 15,849 μGym².

CONCLUSION

Local reference levels were identified. The pooled data has been used to establish an interim European DRL for EVAR procedures.

KEY POINTS

• Abdominal endovascular aneurysm repair (EVAR) requires the use of ionising radiation. • EVAR is a minimally invasive procedure for the treatment of abdominal aortic aneurysms. • Diagnostic reference levels (DRLs) are used to monitor patient radiation exposure. • Radiation dose data was collected from five European centres for EVAR procedures. • Local DRLs have been determined and an interim European DRL is proposed.

Physician and Patient Radiation Exposure During Endovascular Procedures

OPINION STATEMENT

Endovascular procedures expose both patients and physicians to fluoroscopic ionizing radiation that carries a dose-dependent risk of acute toxicity and a small, but demonstrable, long-term risk of malignancy due to resultant genetic mutations. Exposure doses vary widely based upon patient-related factors including body size and anatomic complexity, operator technique, procedure type (diagnostic vs. therapeutic), vascular bed imaged, and imaging equipment employed. Effective dosage may vary as much as 200-fold for physicians and 20-fold for patients depending upon the procedure: for example, complex aortic interventions with branched graft devices may convey mean effective doses of more than 0.4 mSv for physicians and 100 mSv for patients, whereas distal, small-vessel angiography may entail mean effective doses of less than 0.002 mSv for physicians and 5 mSv for patients. Particular attention is given to physicians' ocular exposure, which may cause cataract development, and to hand exposure, which is significantly higher than total body exposure when operators work near the x-ray beam. Given the risks of radiation exposure, numerous strategies have been developed to reduce both physician and patient doses. These measures include physician education about dose-reducing imaging techniques, development of low-dose imaging equipment, introduction of new radiation shielding drapes and caps, and real-time dose monitoring. Here, we review physician and patient effective doses of radiation by procedure type as reported in the literature and present recent data regarding dose-reduction strategies.

Meta-analysis of Cumulative Radiation Duration and Dose During EVAR Using Mobile, Fixed, or Fixed/3D Fusion C-Arms

Purpose: To investigate the total fluoroscopy time and radiation exposure dose during endovascular aortic repairs using mobile, fixed, or fixed C-arms with 3-dimensional image fusion (3D-IF). Methods: A systematic search was performed to identify original articles reporting fluoroscopy time (FT) and the kerma area product (KAP) during endovascular aortic repairs. Data were grouped by noncomplex or complex (fenestrated, branched, or chimney) repairs and stratified by type of C-arm. The search identified 27 articles containing 51 study groups (35 noncomplex and 16 complex) that included 3444 patients. Random-effects meta-analysis and meta-regression models were used to calculate the pooled mean estimates of KAP and FT, as well as any effect of equipment or type of intervention. Results are presented with the 95% confidence interval and the statistical heterogeneity ( I2). Results: Within the noncomplex procedure studies, a significant (p<0.001) increase was found in the pooled mean KAP estimate in the fixed C-arm group (181 Gy·cm2, 95% CI 129 to 233; I2=99.7) compared with the mobile C-arm (78 Gy·cm2, 95% CI 59.6 to 97.3; I2=99.6). For complex cases, use of 3D-IF showed a significantly (p<0.001) lower mean KAP (139 Gy·cm2, 95% CI 85 to 191; I2=94%) compared to using fixed C-arms without 3D-IF (487 Gy·cm2, 95% CI 331 to 643; I2=94%). Conclusion: For equivalent fluoroscopy times, the use of a fixed C-arm in noncomplex procedures leads to higher patient radiation doses compared to a mobile C-arm. Complex procedures, which are predominantly performed using fixed C-arms, are associated with the highest radiation dose per intervention. Using fixed C-arms combined with 3D-IF techniques during complex cases might seem an adequate method to compensate for the higher radiation doses measured when a fixed C-arm is used.

Efficacy Analysis of a Script-based Guide for EVAR Execution: is it Possible to Reduce Patient Exposure to Contrast, Operative Time and Blood Loss even when Advanced Technologies are not Available?

INTRODUCTION

Despite the patient and medical staff exposure to radiation in endovascular aneurysm repair, the benefits of this abdominal aortic aneurysm type of surgical management are justfied by minor recovery time and hospitalization, as well as an option for patients not elected to conventional open repair. In this minimally invasive surgical aproach, time of procedure and radiation doses can be substantial - and the increasing frequency of these procedures and it's complexity have impelled vascular surgeons to face additional and successive risk to occupational radiation exposure. Meticulous study of the computed tomography angiography during the endovascular aneurysm repair preparation allows reduction of unnecessary radiation exposure, as also reduces consecutive image acquisition and contrast use (that may be related to renal overload in susceptible patients). Some studies have proposed strategies to optimize endovascular intervention to reduce contrast use and X-ray exposure. Although they might prove to be effective, they rely on use of additional specific and advanced equipment, available only in major centers. As an alternative to this expensive and restrict technology, it is presented a simpler technique through image manipulation on software OsiriX, aiming to reduce both exposures.

OBJECTIVE

To analyze the efficacy of the adoption of a study protocol and a script-based guide in preparation for endovascular aneurysm repair through verifying it's impact over the surgical procedure - as referred to intravascular contrast infuse, effects over renal function, blood loss and operatory time.

METHODS

A longitudinal prospective study from March 2014 through March 2015, where 30 performed endovascular aneurysm repair were compared to a historic control group. The planning for endovascular aneurysm repair through the patient's tomographic image manipulation in the prospective group was performed with OsiriX MD software. A script-based guide upon gathering detailed computed tomography angiography images was elaborated by the author and distributed to the performing surgical team for appreciation, instruction and pre operatory judgment. Based upon the script, the C-arm gantry angle was specifically corrected in each case of endovascular aneurysm repair, for image optimization and aneurysm's neck visualization. Arteriography was performed under digital subtraction angiography after catheters were positioned according to predicted level description in the referred guide. Statistical analysis were performed with a significance level of 5% (P value<0.05).

RESULTS

There was a statistically significant relationship between the two studied periods and the variables: contrast volume (284.5 vs. 31.8 mL), operative time (207.5 vs. 140.4 min.) and blood loss (798.1 vs. 204.4 mL), revealing that they are considerably larger in the historical control group than in the script guided current group. There was no difference related to the volume of contrast used in the two groups and the occurrence of renal impairment.

CONCLUSION

In the present paper it was possible to demonstrate the impact of the ability to manipulate digital formats of medical images without the need of sophisticated equipment, in adoption of a guide based on the compilation of informations collected with assistance of an accessible software performed on a personal computer. Although we could not prove relation to occurrence of renal impairment, there were direct results on reduction of intravascular contrast use, even as surgical time and blood loss, compared to a previous historical period.

Comparative occupational radiation exposure between fixed and mobile imaging systems

OBJECTIVE

Endovascular intervention exposes surgical staff to scattered radiation, which varies according to procedure and imaging equipment. The purpose of this study was to determine differences in occupational exposure between procedures performed with fixed imaging (FI) in an endovascular suite compared with conventional mobile imaging (MI) in a standard operating room.

METHODS

A series of 116 endovascular cases were performed over a 4-month interval in a dedicated endovascular suite with FI and conventional operating room with MI. All cases were performed at a single institution and radiation dose was recorded using real-time dosimetry badges from Unfors RaySafe (Hopkinton, Mass). A dosimeter was mounted in each room to establish a radiation baseline. Staff dose was recorded using individual badges worn on the torso lead. Total mean air kerma (Kar; mGy, patient dose) and mean case dose (mSv, scattered radiation) were compared between rooms and across all staff positions for cases of varying complexity. Statistical analyses for all continuous variables were performed using t test and analysis of variance where appropriate.

RESULTS

A total of 43 cases with MI and 73 cases with FI were performed by four vascular surgeons. Total mean Kar, and case dose were significantly higher with FI compared with MI. (mean ± standard error of the mean, 523 ± 49 mGy vs 98 ± 19 mGy; P < .00001; 0.77 ± 0.03 mSv vs 0.16 ± 0.08 mSv, P < .00001). Exposure for the primary surgeon and assistant was significantly higher with FI compared with MI. Mean exposure for all cases using either imaging modality, was significantly higher for the primary surgeon and assistant than for support staff (ie, nurse, radiology technologist) beyond 6 feet from the X-ray source, indicated according to one-way analysis of variance (MI: P < .00001; FI: P < .00001). Support staff exposure was negligible and did not differ between FI and MI. Room dose stratified according to case complexity (Kar) showed statistically significantly higher scattered radiation in FI vs MI across all quartiles.

CONCLUSIONS

The scattered radiation is several-fold higher with FI than MI across all levels of case complexity. Radiation exposure decreases with distance from the radiation source, and is negligible outside of a 6-foot radius. Modern endovascular suites allow high-fidelity imaging, yet additional strategies to minimize exposure and occupational risk are needed.

Mechanical thrombectomy using a combined CT/C-arm X-ray system

Background

Mechanical thrombectomy (MT) using stent-retrievers has been proven to be a safe and effective treatment in acute ischemic stroke (AIS), particularly in large vessel occlusion. Other than patient characteristics, time to recanalization is the most important factor linked to outcome. MT is usually performed in a dedicated angiography suite using a floor- and/or ceiling-mounted biplane angiographic system. Here we report our first experience of MT with a new combined CT and mobile C-arm X-ray device setup.

Methods

Patients with AIS underwent stroke imaging (non-contrast enhanced CT, CT perfusion, and CT angiography) using a commercially available 64-slice CT scanner which was modified for combined use with a C-arm system. In patients with large vessel occlusion, MT was conducted without further patient transfer within the CT imaging suite using a mobile C-arm X-ray device equipped with a 30×30 cm (12×12 inch), 1.5×1.5 k full-view flat detector which was positioned between the gantry and patient table. The safety and feasibility of this new system was assessed in preliminary patients.

Results

Angiographic imaging quality of the mobile C-arm was feasible and satisfactory for diagnostic angiography and MT. Using this setup, time between stroke imaging and groin puncture (picture-to-puncture time) was reduced by up to 35 min (including time for preparation of the patient such as intubation).

Conclusions

MT using a combined CT/C-arm system is safe and feasible. The potential advantages, particularly time saving and ensuing improvement in patient outcome, need to be assessed in a larger study.

A comparison study of radiation exposure to patients during EVAR and Dyna CT in an angiosuite vs. an operating theatre

The aim of this study was to assess the patient dosimetric impact of endovascular abdominal aortic aneurysm repair (EVAR), both in an operating theatre (OR) and in an angiosuite (AS), with the facility of Dynamic CT (Dyna CT, Siemens AG, Berlin, Germany). One hundred and forty-six consecutive EVAR procedures dating from May 2011 to March 2013 were analysed. These were performed either in an OR (n = 97) using a mobile C-arm or in an AS (n = 49) equipped with a ceiling-mounted angiography system. Air kerma area product (P(KA)) and total air kerma at reference point (K(a,r)) values were reported for all procedures and Dyna CT. Radiation exposure during EVAR was quite low in the majority of patients but nearly 50 % higher if performed in AS vs. OR. Median Dyna CT K(a,r) was the same as an entire EVAR procedure in OR. The higher patient's radiation exposure recorded in the AS should be balanced with the technical advantages given to the EVAR procedure.

Anatomic and procedural determinants of fluoroscopy time during elective endovascular aortic aneurysm repair

Objective

To identify both the procedural and anatomic factors which determine duration of fluoroscopy during elective endovascular aortic aneurysm repair (EVAR).

Methods

We retrospectively analyzed our prospectively maintained EVAR database for the relationship between fluoroscopy time and both procedural (type of graft, configuration, number of components, surgeon) and anatomic factors reflective of aneurysm complexity (15 variables).

Results

A total of 128 patients underwent elective EVAR with a mean fluoroscopy time of 5.7 ± 3.4 min. The type of grafts used consisted of 41 (32%) Zenith, 85 (66.4%) Endurant and 2 (1.6%) Anaconda, with 105 (82%) being bifurcated and 23 (18%) being aorto-uni-iliac (AUI) in configuration. Both the surgeon performing the procedure ( p = 0.001) and graft configuration (bifurcated vs. AUI, p = 0.03) were found to be predictive of fluoroscopy time; while procedural and anatomic variables were not.

Conclusions

The surgeon’s efficiency in the use of fluoroscopy during EVAR is the most important determinant of total fluoroscopy time. Anatomic complexity, make of device, and number of components inserted have minimal impact on duration of fluoroscopy. An endovascular surgeon’s ability to curtail fluoroscopy duration is the key component in minimizing radiation exposure to both the surgical team and the patient.

Editor's choice--Angulation of the C-arm during complex endovascular aortic procedures increases radiation exposure to the head

OBJECTIVES/BACKGROUND

The increased complexity of endovascular aortic repair necessitates longer procedural time and higher radiation exposure to the operator, particularly to exposed body parts. The aims were to measure directly exposure to radiation of the bodies and heads of the operating team during endovascular repair of thoracoabdominal aortic aneurysms (TAAA), and to identify factors that may increase exposure.

METHODS

This was a single-centre prospective study. Between October 2013 and July 2014, consecutive elective branched and fenestrated TAAA repairs performed in a hybrid operating room were studied. Electronic dosimeters were used to measure directly radiation exposure to the primary (PO) and assistant (AO) operator in three different areas (under-lead, over-lead, and head). Fluoroscopy and digital subtraction angiography (DSA) acquisition times, C-arm angulation, and PO/AO height were recorded.

RESULTS

Seventeen cases were analysed (Crawford II-IV), with a median operating time of 280 minutes (interquartile range 200-330 minutes). Median age was 76 years (range 71-81 years); median body mass index was 28 kg/m(2) (25-32 kg/m(2)). Stent-grafts incorporated branches only, fenestrations only, or a mixture of branches and fenestrations. A total of 21 branches and 38 fenestrations were cannulated and stented. Head dose was significantly higher in the PO compared with the AO (median 54 μSv [range 24-130 μSv] vs. 15 μSv [range 7-43 μSv], respectively; p = .022), as was over-lead body dose (median 80 μSv [range 37-163 μSv] vs. 32 μSv [range 6-48 μSv], respectively; p = .003). Corresponding under-lead doses were similar between operators (median 4 μSv [range 1-17 μSv] vs. 1 μSv [range 1-3 μSv], respectively; p = .222). Primary operator height, DSA acquisition time in left anterior oblique (LAO) position, and degrees of LAO angulation were independent predictors of PO head dose (p < .05).

CONCLUSIONS

The head is an unprotected area receiving a significant radiation dose during complex endovascular aortic repair. The deleterious effects of exposure to this area are not fully understood. Vascular interventionalists should be cognisant of head exposure increasing with C-arm angulation, and limit this manoeuvre.

Cumulative radiation dose and radiation risk from medical imaging in patients subjected to endovascular aortic aneurysm repair

PURPOSE

This study was undertaken to quantify the cumulative effective dose (CED) of radiation and the dose to relevant organs in endovascular aortic repair (EVAR) patients, to assess radiation risks and to evaluate the clinical usefulness of multi-detector computed tomography (MDCT) follow-up.

MATERIALS AND METHODS

The radiation exposures were obtained from 71 consecutive EVAR patients with a follow-up duration ≥1 year. Dose calculations were performed on an individual basis and expressed as effective doses and organ doses. Radiation risk was expressed as risk of exposure-induced death (%), using the biological effects of ionising radiation model. Two radiologists independently assessed the images for abdominal aortic aneurysm expansion without endoleaks, thrombotic occlusion, endoleaks and device migration. They first reviewed arterial imaging alone and subsequently added non-contrast and delayed phases to determine the overall performance.

RESULTS

The median total CED and annual CED were 224 and 104 mSv per patient-year. The median cumulative organ doses were 191, 205, 230, 269 and 271 mSv for lung, bone marrow, liver, colon and stomach, respectively. The average risk of exposure-induced death was 0.8 % (i.e., odds 1 in 130). All the findings related to EVAR outcome and leading to a change in patient management were visible during the arterial phase of the MDCT angiography. Omission of the unenhanced scan and the venous phase of the MDCT angiography would have led to a significant reduction of about 60 % of the associated MDCT radiation exposure in a single patient.

CONCLUSIONS

EVAR patients received high radiation doses and the excess cancer risk attributable to radiation exposure is not negligible. The unenhanced scan and the venous phase of the MDCT angiography could have been omitted without compromising the utility of the examination and with a significant reduction of doses and associated risks.

Current state in tracking and robotic navigation systems for application in endovascular aortic aneurysm repair

OBJECTIVE

This study reviewed the current developments in manual tracking and robotic navigation technologies for application in endovascular aortic aneurysm repair (EVAR).

METHODS

EMBASE and MEDLINE databases were searched for studies reporting manual tracking or robotic navigation systems that are able to manipulate endovascular surgical tools during abdominal or thoracic aortic aneurysm repair. Reports were grouped by the navigation systems and categorized into phantom, animal, and clinical studies. First, the general characteristics of each system were compared. Second, target registration error and deployment error were used to compare the accuracy of the tracking systems. Third, all systems were reviewed for fluoroscopy time (FT), radiation dose, and contrast volumes, if reported, in rigid and nonrigid studies. Fourth, vascular cannulation performance of the systems was compared, studying cannulation time, Imperial College Complex Cannulation Scoring Tool score, and the number of wall hits and catheter movements within rigid studies.

RESULTS

Of 721 articles and references found, 18 studies of four different navigation systems were included: the Aurora (Northern Digital, Waterloo, Ontario, Canada) tracking system, the StealthStation (Medtronic Inc, Minneapolis, Minn) tracking system, an ultrasound localization tracking system, and the Sensei (Hansen Medical, Mountain View, Calif) steerable remote-controlled robotic navigation system. The mean tracking accuracy averaged 1 mm for the three manual tracking systems measured in a rigid environment. An increase of target registration error reaching >3 mm was reported when measured in a nonrigid experimental environment or due to external distortion factors. Except within small-animal studies or case studies, no evidence was found on reduction of clinical outcome parameters, such as FT, radiation dose, and contrast volumes, within clinical EVAR. A comparison of vascular cannulation performance in rigid studies revealed that the Sensei robotic system might have an advantage during advanced cannulation compared with standard cannulation within complex cannulations tasks.

CONCLUSIONS

This review summarizes the current studies on manual tracking and robotic navigation systems for application in EVAR. The main focus of these systems is improving aortic vessel cannulation, required in complex EVAR, in which the robotic system with the improved steerability is favored over manual tracking systems or conventional cannulation. All reviewed tracking systems still require X-ray for anatomic imaging, stent graft deployment, and device registration. Although the current reviewed endovascular navigation systems have shown their potential in phantom and animal studies, clinical trials are too limited to conclude that these systems can improve EVAR outcomes or that they can systematically reduce FTs, radiation doses, and contrast volumes during (complex) EVAR.

Review of the Use of Ionizing Radiation in Endovascular Aneurysm Repair

Endovascular repair for aortic aneurysm (EVAR) is rapidly increasing in popularity. The nature of this intervention requires significant exposure to ionizing radiation both during the procedure and for postoperative surveillance, generally in the form of computed tomography. Here the authors review the literature for radiation exposure during EVAR, both for the patient and the physician.

Three-dimensional fusion computed tomography decreases radiation exposure, procedure time, and contrast use during fenestrated endovascular aortic repair

OBJECTIVE

Endovascular surgery has revolutionized the treatment of aortic aneurysms; however, these improvements have come at the cost of increased radiation and contrast exposure, particularly for more complex procedures. Three-dimensional (3D) fusion computed tomography (CT) imaging is a new technology that may facilitate these repairs. The purpose of this analysis was to determine the effect of using intraoperative 3D fusion CT on the performance of fenestrated endovascular aortic repair (FEVAR).

METHODS

Our institutional database was reviewed to identify patients undergoing branched or FEVAR. Patients treated using 3D fusion CT were compared with patients treated in the immediate 12-month period before implementation of this technology when procedures were performed in a standard hybrid operating room without CT fusion capabilities. Primary end points included patient radiation exposure (cumulated air kerma: mGy), fluoroscopy time (minutes), contrast usage (mL), and procedure time (minutes). Patients were grouped by the number of aortic graft fenestrations revascularized with a stent graft, and operative outcomes were compared.

RESULTS

A total of 72 patients (41 before vs 31 after 3D fusion CT implementation) underwent FEVAR from September 2012 through March 2014. For two-vessel fenestrated endografts, there was a significant decrease in radiation exposure (3400 ± 1900 vs 1380 ± 520 mGy; P = .001), fluoroscopy time (63 ± 29 vs 41 ± 11 minutes; P = .02), and contrast usage (69 ± 16 vs 26 ± 8 mL; P = .0002) with intraoperative 3D fusion CT. Similarly, for combined three-vessel and four-vessel FEVAR, significantly decreased radiation exposure (5400 ± 2225 vs 2700 ± 1400 mGy; P < .0001), fluoroscopy time (89 ± 36 vs 64 ± 21 minutes; P = .02), contrast usage (90 ± 25 vs 39 ± 17 mL; P < .0001), and procedure time (330 ± 100 vs 230 ± 50 minutes; P = .002) was noted. Estimated blood loss was significantly less (P < .0001), and length of stay had a trend (P = .07) toward being lower for all patients in the 3D fusion CT group.

CONCLUSIONS

These results demonstrate that use of intraoperative 3D fusion CT imaging during FEVAR can significantly decrease radiation exposure, procedure time, and contrast usage, which may also decrease the overall physiologic impact of the repair.

Improved efficiency and safety for EVAR with utilization of a hybrid room

OBJECTIVE

Access to a hybrid endovascular suite is touted as a necessity for advanced endovascular aneurysm repair (EVAR) to improve imaging accuracy and safety. Yet there remain little data documenting this intuitive advantage of a hybrid setup versus a traditional operating room (OR) utilizing a portable fluoroscopic unit (C-arm) for imaging. We hypothesized that standard elective EVAR performed in a hybrid suite would improve procedural efficiency and accuracy, as well minimize patient exposure to both contrast and radiation.

METHODS

We retrospectively reviewed a single attending surgeon's EVAR practice, which encompassed the transition to a hybrid endovascular suite (opened July 2010). Only consecutive abdominal aneurysms were included in the analysis to attempt to create a homogenous cohort. All emergent, aorto-uni-iliac (AUI), snorkel, fenestrated, or hybrid procedures were excluded. Standard variables evaluated and compared between the two study subgroups included fluoroscopy time, operative time, contrast use, stent-graft component utilization, complication rates, and short-term endoleaks.

RESULTS

From January 2008 to August 2012, we performed 213 EVAR procedures for abdominal aortic aneurysms. After excluding emergent, AUI, snorkel, or hybrid procedures, we analyzed 109 routine EVARs. Fifty-eight consecutive cases were done in the OR with a C-arm until July 2010, and the last 51 cases were done in the hybrid room. Both groups were well matched in terms of demographics, aneurysm morphology, and procedural characteristics. No difference was found in terms of complication rates or operative mortality, although there was a trend towards decreased fluoroscopy time, type I/III endoleaks, and a number of additional endograft components utilized. Compared with patients repaired in the OR/C-arm, EVAR done in the hybrid room resulted in less total OR time and contrast usage (p < .05).

CONCLUSIONS

Routine EVAR performed in a hybrid fixed-imaging suite affords greater efficiency and less harmful exposure of contrast and possible radiation to the patient. Accurate imaging quality and deployment is associated with less need for additional endograft components, which should lead to improved cost efficiency. Confirmation of these findings might be necessary in a randomized control trial to fully justify the capital expenditure necessary for hybrid endovascular suites.