Impact of Hybrid Operating Rooms on Long-Term Clinical Outcomes Following Fenestrated and Branched Endovascular Aortic Repair

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A SiMplified bARe-Wire Target Vessel (SMART) Technique for Fenestrated Endovascular Aortic Repair

PURPOSE

The aim of this study was to present a new technique for fenestrated endovascular aortic aneurysm repair (FEVAR) and to review its preliminary results. The SiMplified bARe-wire Target vessel (SMART) technique for FEVAR aims to simplify the procedure by avoiding guiding sheaths into visceral arteries during the main graft deployment.

MATERIALS AND METHODS

The SMART technique requires a 12 to 16Fr contralateral introducer, depending on number of fenestrations-compared with standard 18 to 22Fr for 3 to 4 FEVAR-to achieve target vessel catheterization and stenting during FEVAR by avoiding the use of parallel 6 to 7Fr guiding sheaths into each visceral vessel. Fenestrations are sequentially catheterized, assisted by a steerable sheath. A Rosen wire is maintained in each fenestration, with a single sheath parked in the final target vessel while releasing the fenestrated graft. Data on patients treated for pararenal or thoracoabdominal aortic aneurysms with FEVAR, adopting the SMART technique, were retrospectively reviewed. End points were technical success, intraprocedural variables, 90-day mortality, major adverse events (MAEs), and target vessel patency.

RESULTS

From May 2018 to December 2020, 57 consecutive patients were treated for pararenal or thoracoabdominal aortic aneurysms. Median total procedure time and total fluoroscopy time were 223 (196-271) minutes and 81 (71-94) minutes, respectively. Primary technical success was 96.4% (55/57). No misalignment occurred from graft deployment. The total number of fenestrations was 169, including 54 left and 53 right renal arteries, 43 superior mesenteric arteries and 18 celiac trunks (3.0±0.9 vessels/patient), with target vessel technical success of 98.2%. During the first 90 days, there were no deaths (0%). The MAEs included acute kidney injury (AKI) in 3 patients (5%) with no new dialysis onset, respiratory failure requiring prolonged ventilation in 2 patients (4%), myocardial ischemia in 1 patient (2%), but no lower limb ischemia, stroke, or spinal cord ischemia (SCI) occurred. After a mean follow-up of 14±10 months, there was 1 aortic-related death. Primary and assisted primary target vessel patency was 94.6%±1.8 and 97.0%±1.3% respectively.

CONCLUSIONS

The SMART technique proved to be a safe alternative to standard FEVARs, with excellent technical result and acceptable target vessel patency at mid-term, while reducing the risk for introducer-induced lower limb ischemia, related complications, and morbidity.

CLINICAL IMPACT

This study evalautes the outcome of fenestrated endovascular aortic repair (FEVAR) procedures at Uppsala university hospital using a simplified bare-wire Target vessel (SMART) technique. The SMART technique requires a smaller contralateral introducer compared to standard 18-22Fr for 3-4 FEVAR to achieve target vessel catetherization and stenting. Fifty-seven consecutive patients were treated for pararenal or thoracoabdominal aortic aneurysms. The SMART technique proved to be a safe alternative to standard FEVARs with excellent technical result and acceptable target vessel patency at mid-term, while reducing the risk for introducer-induced lower limb ischemia, related complications, and morbidity.

Added Value of Selective Intra-arterial Cone-Beam CT Angiography in the Management of Visceral Artery Aneurysms

PURPOSE

The aim of this study is to evaluate the value of selective intra-arterial cone-beam computed tomography angiography (CBCTA) relative to conventional computed tomography angiography (CTA) in understanding visceral artery aneurysm (VAA) morphology, and its impact on treatment planning.

MATERIALS AND METHODS

Between January 2017 and August 2021, all patients who had a diagnosis of VAA and underwent intraoperative CBCTA imaging were retrospectively reviewed. Impact on treatment decisions, optimal C-arm angulations derived from CBCTA, and additional radiation exposure were reported. Two blinded independent reviewers qualitatively reviewed CBCTA and conventional CTA images. A 5-point Likert scale (1=poor image quality, 5=excellent image quality) was used to assess the overall image quality of each modality. Number of vessels arising from the aneurysm sac was counted.

RESULTS

A total of 16 patients had a diagnosis of VAA during the study period, of whom 10 patients had intraoperative CBCTA and conventional CTA available for review. Out of 10 patients, 7 underwent successful endovascular treatment, 2 were deemed not amenable for endovascular embolization based on intraoperative CBCTA findings, and 1 had resolved pseudoaneurysm. Total fluoroscopy time and radiation dose (dose area product [DAP] and skin dose) for all procedures were 27.7 ± 19.9 minutes, 28 362 (±18 651) µGy*m2, and 1879 (±1734) mGy, respectively. Radiation exposure from CBCTA (DAP and skin dose) was 5703 (±3967) µGy*m2 and 223.6 (±141.3) mGy, respectively. In patients who underwent endovascular treatment, the proportional DAP from CBCTA was 18.3% (±15.3%) of the total procedural radiation dose. Qualitative rating of overall image quality of CBCTA images was superior to CTA images (mean score: 4.55 vs 3, p<0.001). More branch vessels arising from the VAA were identified by all reviewers in CBCTA as compared with conventional CTA (median, min-max: 3, 0-4 vs 2,1-3 vessels).

CONCLUSION

Intraoperative CBCTA after selective intra-arterial contrast injection, with better spatial resolution, provided better delineation of visceral aneurysm morphology as compared with conventional, intravenous CTA and enabled optimal treatment planning at a reasonable additional radiation exposure.

CLINICAL IMPACT

Visceral artery aneurysms (VAA) are often diagnosed incidentally by conventional computed tomographic angiography (CTA). Endovascular treatment typically requires selective angiographies at multiple projections to better understand aneurysm morphology, location, and efferent branch vessels. Intra-arterial cone-beam CT angiography (CBCTA) for VAA has the advantage of selective contrast opacification, better spatial resolution, and three-dimensional/multi-planar visualization of aneurysm morphology. In addition, CBCTA enables identification of optimal C-arm working projection for subsequent endovascular treatment. The aim of this study is to evaluate the value of intraoperative CBCTA relative to conventional CTA in understanding visceral artery aneurysm morphology and its impact on treatment planning.

Renal and Visceral Artery Configuration During the First Year of Follow-Up After Fenestrated Aortic Aneurysm Repair Using the Anaconda Stent-graft: A Prospective Longitudinal Multicenter Study With ECG-Gated CTA Scans

OBJECTIVE

The performance of fenestrated endovascular aortic aneurysm repair (FEVAR) may be compromised by complications related to the dynamic vascular environment. The aim of this study was to analyze the behavior of FEVAR bridging stent configurations during the cardiac cycle and during follow-up to improve our understanding on treatment durability.

DESIGN

Twenty-one patients presenting with complex abdominal aortic aneurysms (AAAs; 9 juxtarenal/6 pararenal/3 paravisceral/1 thoracoabdominal aortic aneurysm type IV), treated with a fenestrated Anaconda (Terumo Aortic, Inchinnan, Scotland, UK) with Advanta V12 bridging stents (Getinge, Merrimack, NH, USA), were prospectively enrolled in a multicenter observational cohort study and underwent electrocardiogram (ECG)-gated computed tomographic angiography (CTA) preoperatively, at discharge, 7-week, and 12-month follow-ups.

METHODS

Fenestrated endovascular aortic aneurysm repair stability was assessed considering the following variables: branch angle as the angle between the aorta and the target artery, end-stent angle as the angle between the end of the bridging stent and the native artery downstream from it, curvature and tortuosity index (TI) to describe the bending of the target artery. Body-bridging stent stability was assessed considering bridging stent flare lengths, the distances between the proximal sealing stent-ring and fenestrations and the distance between the fenestration and first apposition in the target artery.

RESULTS

Renal branch angles significantly increased after FEVAR toward a perpendicular position (right renal artery from median 60.9°, inter quartile range [IQR]=44.2-84.9° preoperatively to 94.4°, IQR=72.6-99.8°, p=0.001 at 12-month follow-up; left renal artery [LRA], from 63.7°, IQR=55.0-73.0° to 94.3°, IQR=68.2-105.6°, p<0.001), while visceral branch angles did not. The mean dynamic curvature only decreased for the LRA from preoperative (3.0, IQR=2.2-3.8 m-1) to 12-month follow-up (1.9, IQR=1.4-2.6 m-1, p=0.027). The remaining investigated variables did not seem to show any changes over time in this cohort.

CONCLUSIONS

Fenestrated endovascular aortic aneurysm repair for complex AAAs using the Anaconda fenestrated stent-graft and balloon-expandable Advanta V12 bridging stents demonstrated stable configurations up to 12-month follow-up, except for increasing renal branch angles toward perpendicular orientation to the aorta, yet without apparent clinical consequences in this cohort.

CLINICAL IMPACT

This study provides detailed information on the cardiac-pulsatility-induced (dynamic) and longitudinal geometry deformations of the target arteries and bridging stents after fenestrated endovascular aortic aneurysm repair (FEVAR) up to 12-month follow-up. The configuration demonstrated limited dynamic and longitudinal deformations in terms of branch angle, end-stent angle, curvature, and tortuosity index (TI), except for the increasing renal branch angles that go toward a perpendicular orientation to the aorta. Overall, the results suggest that the investigated FEVAR configurations are stable and durable, though careful consideration of increasing renal branch angles and significant geometry alterations is advised.

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.

Intraoperative computed tomography during fenestrated and branched endovascular aortic repair: a feasibility study

BACKGROUND

Endovascular aortic repair with fenestrated or branched endografts is technically challenging, and proper intraoperative assessment of all stent graft components with only angiography and fluoroscopy can be difficult. Intraoperative computed tomography (CT) imaging can be a valuable aid for the operators in the evaluation of stent grafting results prior to completion of surgery.

PURPOSE

To examine the feasibility of performing intraoperative CT imaging during fenestrated and branched endovascular aortic repair (f-bEVAR) under sterile conditions and with patients under general anesthesia.

MATERIAL AND METHODS

Intraoperative CT imaging was performed in 10 patients undergoing elective aortic repair with fenestrated or branched endografts. Adverse events, time consumption for CT set-up and image acquisition, and additional radiation dose to the patient were recorded. CT image quality was graded. Immediate corrective maneuvers performed based on the CT findings was registered.

RESULTS

There were no adverse events related to intraoperative CT imaging. The median additional operating time by including intraoperative CT was 16 min (interquartile range [IQR] = 12-19), comprising 7% of the median total operating time. The median estimated additional radiation dose to the patient was 4.8 mSv (IQR = 3.8-4.9). All intraoperative CT examinations were considered to be of sufficient quality for stent graft evaluation. No immediate corrective procedures were performed on the basis of CT findings in this study cohort.

CONCLUSION

CT imaging intraoperatively during f-bEVAR is feasible with an acceptable increase in operating time and radiation dose.

"Redo" 2D-3D Fusion Technique during Endovascular Redo Aortic Repair

PURPOSE

The present study aims to describe a new 2D-3D fusion registration method in the case of endovascular redo aortic repair and compare the accuracy of the registration using the previously implanted devices vs. bones as landmarks.

MATERIALS AND METHODS

This single-center study prospectively analyzed all the patients that underwent elective endovascular re-interventions using the Redo Fusion technique between January 2016 and December 2021 at the Vascular Surgery Unit of the Fondazione Policlinico Universitario A. Gemelli (FPUG)-IRCCS in Rome, Italy. The fusion overlay was performed twice, first using bone landmarks (bone fusion) and the second using radiopaque markers of a previous endovascular device (redo fusion). The pre-operative 3D model was fused with live fluoroscopy to create a roadmap. Longitudinal distances between the inferior margin of the target vessel in live fluoroscopy and the inferior margin of the target vessel in bone fusion and redo fusion were measured.

RESULTS

This single-center study prospectively analyzed 20 patients. There were 15 men and five women, with a median age of 69.7 (IQR 42) years. The median distance between the inferior margin of the target vessel ostium in digital subtraction angiography and the inferior margin of the target vessel ostium in bone fusion and redo fusion was 5.35 mm and 1.35 mm, respectively (p ≤ 0.0001).

CONCLUSIONS

The redo fusion technique is accurate and allows the optimization of X-ray working views, supporting the endovascular navigation and vessel catheterization in case of endovascular redo aortic repair.

Incidence, Prognostic Significance, and Risk Factors of Acute Kidney Injury Following Elective Infrarenal and Complex Endovascular Aneurysm Repair

OBJECTIVE

Acute kidney injury (AKI) is a well known complication following cardiovascular procedures. The objective was to assess the incidence, risk factors, and prognostic significance of AKI after infrarenal endovascular aneurysm repair (EVAR) and complex EVAR (cEVAR; fenestrated or branched EVAR).

METHODS

Consecutive patients undergoing elective infrarenal EVAR or cEVAR between 2000 and 2018 in two large teaching hospitals in the Netherlands were included. AKI was determined by serum creatinine levels increasing > 1.5 times or by an absolute increase of 26.5 mmol/L from baseline value (KDIGO criteria). The primary outcome was incidence of peri-operative AKI development. Secondary outcomes included mid-term renal function (RIFLE criteria), overall survival, and risk factors for AKI development. To determine survival and risk factors for AKI, multivariable Cox regression and logistic regression analyses were performed, accounting for pre-operative renal function and other confounders.

RESULTS

In total, 540 patients who underwent infrarenal EVAR with 147 patients who underwent cEVAR also included. The incidence of AKI was 8.7% (n = 47) in infrarenal EVAR patients and 23% (n = 34) in cEVAR patients (fenestrated EVAR 18%; branched EVAR 38%). In contrast to patients without AKI, the renal function of surviving patients with AKI remained significantly reduced at six weeks and did not return to pre-operative values following infrarenal EVAR (three year estimated glomerular filtration rate [eGFR] 59.3 ± 23.1 mL/min/1.73m2vs. pre-operative eGFR 74.0 ± 21.7 mL/min/1.73m2; p = .006) or following cEVAR (three year eGFR 52.0 ± 23.7 mL/min/1.73m2vs. pre-operative eGFR 65.4 ± 18.6 mL/min/1.73m2; p = .082). After risk adjusted analysis, compared with non-AKI, post-operative AKI development was associated with a higher three year mortality rate following both infrarenal and cEVAR (infrarenal EVAR mortality hazard ratio [HR 1.6, 95% confidence interval [CI] 1.01 - 2.7 [p = .046]; cEVAR mortality HR 2.4, 95% CI 1.1 - 5.2 [p = .033]). Following multivariable logistic regression, pre-operative chronic kidney disease (eGFR < 60 mL/min/1.73m2; odds ratio [OR] 2.2, 95% CI 1.03 - 4.8) and neck diameter (OR 1.1, 95% CI 1.01 - 1.2) were significantly associated with AKI following infrarenal EVAR, whereas for cEVAR only contrast volume (OR 1.1, 95% CI 1.0 - 1.2]) was found to be statistically significantly associated with AKI.

CONCLUSION

AKI is a well described complication following infrarenal EVAR and is common after cEVAR. As AKI seems to be associated with permanent renal deterioration and lower survival, efforts to prevent AKI are essential. Future studies are required to assess what factors are associated with a higher risk of developing AKI following cEVAR.

Incidence, predictive factors, and outcomes of intraprocedure adverse events during fenestrated-branched endovascular aortic repair of complex abdominal and thoracoabdominal aortic aneurysms

OBJECTIVE

To evaluate the incidence of intraoperative adverse events (IAEs) and their impact on outcomes after fenestrated-branched endovascular aortic repair (FB-EVAR) of complex abdominal aortic aneurysms and thoracoabdominal aortic aneurysm (TAAAs).

METHODS

We reviewed the clinical and imaging data of 600 consecutive patients (445 males; mean age, 75 ± 8 years) who underwent FB-EVAR between 2007 and 2019 in a single institution. IAE was defined as any intraoperative complication or technical problem requiring additional and unplanned procedures, and was classified as access-related, target artery (TA)-related, or graft-related. End points included rates of IAEs, 30-day or in-hospital mortality, major adverse events, patient survival, freedom from secondary intervention, and TA instability.

RESULTS

A total of 122 IAEs were identified in 105 patients (18%). IAEs were TA-related in 55 patients (9%), access-related in 46 patients (8%), and graft-related in seven patients (1%). Female sex was more frequent among patients with IAEs (44% vs 22%; P < .001). Patients with IAEs had smaller renal artery diameter (-0.4 mm, 5.4 ± 0.8 mm vs 5.8 ± 0.9 mm; P < .001), and were treated more often for TAAAs (72% vs 54%; P < .03). Technical success was achieved in 96.5% of patients and was lower for patients with IAEs (82% vs 99%; P < .001). Major adverse events were significantly more frequent among patients who had IAEs (odds ratio [OR], 1.98; 95% confidence interval [CI], 1.21-3.25), most due to acute kidney injury (27% vs 11%; P < .001) including new-onset dialysis (5% vs 1%; P = .01). On multivariate logistic regression model, female sex (OR, 2.5; 95% CI, 1.5-4.0), TA stenosis >50% (OR, 2.0; 95% CI, 1.3-3.3), and Crawford Extent II TAAA (OR, 1.9; 95% CI, 1.1-3.3) were predictive of IAEs, whereas preloaded design (OR, 0.6; 95% CI, 0.4-0.9) and TA diameter (+1 mm; OR, 0.6; 95% CI, 0.4-0.9) were protective of IAEs. IAEs negatively affected secondary intervention (hazard ratio [HR], 1.6; 95% CI, 1.1-2.3) and TA instability (HR, 2.5; 95% CI, 1.2-5.4); however, IAEs did not affect patient survival (HR, 1.0; 95% CI, 0.7-1.4).

CONCLUSIONS

IAEs are common, occurring in nearly one of five patients treated with FB-EVAR for complex aortic aneurysms, and have a negative impact on clinical outcomes. IAEs were associated with female sex, TA diameter, and more extensive aortic disease.

Dynamic, Time-Resolved Computed Tomography Angiography Technique to Characterize Aortic Endoleak Type, Inflow and Provide Guidance for Targeted Treatment

PURPOSE

To illustrate dynamic, time-resolved CTA (d-CTA) imaging technique in characterizing aortic endoleak type/inflow using quantitative parameters and its value in providing image guidance for targeted treatment approach.

TECHNIQUE

Dedicated endoleak protocol involved acquiring multiple time-resolved contrast enhanced scans using third-generation CT scanner (Somatom Force^®, Siemens Healthineers). Parameters such as scan field of view (FOV), kV, number/timing of scans were customized based on patient's body-mass-index, timing bolus, and prior imaging findings. D-CTA image datasets were evaluated qualitatively and quantitatively using time-attenuation curves (TAC) analysis after motion correction using a dedicated software (syngo.via^®, Siemens). D-CTA findings from 4 illustrative cases demonstrating type I, type II (inferior mesenteric and lumbar artery inflow), and type III endoleak were illustrated. TAC analysis with time to peak parameter enabled better characterization of endoleak type and inflow. During endoleak intervention, target vessels from d-CTA images were electronically annotated and overlaid on fluoroscopy using 2D-3D image fusion to provide image guidance for targeted treatment.

CONCLUSION

D-CTA imaging with TAC analysis characterizes aortic endoleak type and inflow, in addition to providing image guidance for targeted endoleak treatment. Such dynamic, time-resolved imaging techniques may provide further insights into understanding aortic endoleak that remains an Achilles heel for endovascular aortic aneurysm repair.