Endovascular Repair of Thoracic and Abdominal Aortic Aneurysms: Pre- and Postprocedural Imaging

2022 ACC/AHA guideline for the diagnosis and management of aortic disease: A report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease" provides recommendations to guide clinicians in the diagnosis, genetic evaluation and family screening, medical therapy, endovascular and surgical treatment, and long-term surveillance of patients with aortic disease across its multiple clinical presentation subsets (ie, asymptomatic, stable symptomatic, and acute aortic syndromes).

METHODS

A comprehensive literature search was conducted from January 2021 to April 2021, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through June 2022 during the guideline writing process, were also considered by the writing committee, where appropriate.

STRUCTURE

Recommendations from previously published AHA/ACC guidelines on thoracic aortic disease, peripheral artery disease, and bicuspid aortic valve disease have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with aortic disease have been developed. There is added emphasis on the role of shared decision making, especially in the management of patients with aortic disease both before and during pregnancy. The is also an increased emphasis on the importance of institutional interventional volume and multidisciplinary aortic team expertise in the care of patients with aortic disease.

2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease" provides recommendations to guide clinicians in the diagnosis, genetic evaluation and family screening, medical therapy, endovascular and surgical treatment, and long-term surveillance of patients with aortic disease across its multiple clinical presentation subsets (ie, asymptomatic, stable symptomatic, and acute aortic syndromes).

METHODS

A comprehensive literature search was conducted from January 2021 to April 2021, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through June 2022 during the guideline writing process, were also considered by the writing committee, where appropriate. Structure: Recommendations from previously published AHA/ACC guidelines on thoracic aortic disease, peripheral artery disease, and bicuspid aortic valve disease have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with aortic disease have been developed. There is added emphasis on the role of shared decision making, especially in the management of patients with aortic disease both before and during pregnancy. The is also an increased emphasis on the importance of institutional interventional volume and multidisciplinary aortic team expertise in the care of patients with aortic disease.

2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease" provides recommendations to guide clinicians in the diagnosis, genetic evaluation and family screening, medical therapy, endovascular and surgical treatment, and long-term surveillance of patients with aortic disease across its multiple clinical presentation subsets (ie, asymptomatic, stable symptomatic, and acute aortic syndromes).

METHODS

A comprehensive literature search was conducted from January 2021 to April 2021, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through June 2022 during the guideline writing process, were also considered by the writing committee, where appropriate.

STRUCTURE

Recommendations from previously published AHA/ACC guidelines on thoracic aortic disease, peripheral artery disease, and bicuspid aortic valve disease have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with aortic disease have been developed. There is added emphasis on the role of shared decision making, especially in the management of patients with aortic disease both before and during pregnancy. The is also an increased emphasis on the importance of institutional interventional volume and multidisciplinary aortic team expertise in the care of patients with aortic disease.

Endoleak after Endovascular Abdominal Aortic Aneurysm Repair Treated by Bilateral Transradial Access: Case Report

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Abdominal aortic aneurysms: pre- and post-procedural imaging

Abdominal aortic aneurysm (AAA) is a relatively common, potentially life-threatening disorder. Rupture of AAA is potentially catastrophic with high mortality. Intervention for AAA is indicated when the aneurysm reaches 5.0-5.5 cm or more, when symptomatic, or when increasing in size > 10 mm/year. AAA can be accurately assessed by cross-sectional imaging including computed tomography angiography and magnetic resonance angiography. Current options for intervention in AAA patients include open surgery and endovascular aneurysm repair (EVAR), with EVAR becoming more prevalent over time. Cross-sectional imaging plays a crucial role in AAA surveillance, pre-procedural assessment, and post-EVAR management. This paper will discuss the current role of imaging in the assessment of AAA patients prior to intervention, in evaluation of procedural complications, and in long-term follow-up of EVAR patients.

Type II endoleaks: diagnosis and treatment algorithm

Elective abdominal aortic aneurysm (AAA) repair is recommended for aneurysms greater than 5.5 cm, symptomatic, or rapidly expanding more than 0.5 cm in 6 months. Seventy-five percent of AAAs today are treated with endovascular aneurysm repair (EVAR) rather than open repair. This is fostered by the lower periprocedural mortality, complications, and length of hospital stay associated with EVAR. However, some studies have demonstrated EVAR to result in higher reintervention rates than with open repair, largely due to endoleaks. Type II is the most common, making up 10-25% of all endoleaks. Type II endoleaks, can potentially enlarge and pressurize the aneurysm sac with a risk of rupture. However, many type II endoleaks spontaneously resolve or never lead to sac enlargement. Imaging surveillance and approaches to management of type II endoleaks are reviewed here.

Outcomes of type 2 endoleaks detected on venous phase CT arteriography

PURPOSE

The majority of type 2 endoleaks (T2EL) are identified on computed tomography angiography (CTA) both on arterial and venous phase. There is a subset of T2EL that are demonstrated only on venous phase CTA. This study was done to report the outcomes of T2EL detected only on venous phase CTA.

MATERIALS AND METHODS

A total of 261 consecutive T2EL treated via embolization were reviewed for the presence of endoleak demonstrated only on venous phase CTA. A group of 16 patients (12 men, 4 women; mean age, 80.1 years) was identified who had pre-embolization venous phase T2EL. Patients were evaluated for presence of T2EL after embolization, change in aneurysm diameter, and need for further intervention.

RESULTS

The prevalence of venous phase T2EL was 6.1% (16/261; 95%CI: 3.2%-9.0%). On post-embolization CTA, the rate of successful embolization at 6 months was 2/12 (17%; 95%CI: 0%-38%). At 6-month follow-up, mean change in aneurysm diameter was +2.3mm (n=12; 95%CI: -0.5mm to +5.0mm). In total, 4/16 (25%; 95%CI: 4%-46%) underwent re-embolization and 4/16 (25%, 95%CI: 4%-46%) underwent conversion to open repair. There was one aneurysm rupture, which was successfully treated surgically.

CONCLUSION

These results suggest that venous phase T2EL are not as responsive to embolization as standard T2EL and emphasize the need to follow patients with venous phase T2EL closely.

Identification of Factors Influencing Cumulative Long-Term Radiation Exposure in Patients Undergoing EVAR

Patients who undergo endovascular repair of aortic aneurysms (EVAR) require life-long surveillance because complications including, in particular, endoleaks, aneurysm rupture, and graft dislocation are diagnosed in a certain share of the patient population and may occur at any time after the original procedure. Radiation exposure in patients undergoing EVAR and post-EVAR surveillance has been investigated by previous authors. Arriving at realistic exposure data is essential because radiation doses resulting from CT were shown to be not irrelevant. Efforts directed at identification of factors impacting the level of radiation exposure in both the course of the EVAR procedure and post-EVAR endovascular interventions and CTAs are warranted as potentially modifiable factors may offer opportunities to reduce the radiation. In the light of the risks found to be associated with radiation exposure and considering the findings above, those involved in EVAR and post-EVAR surveillance should aim at optimal dose management.

The role of contrast-enhanced ultrasound imaging in the follow-up of patients post-endovascular aneurysm repair

Endovascular aneurysm repair is a minimally invasive technique for the treatment of abdominal aortic aneurysms. Patients who undergo endovascular aneurysm repair are potentially at risk of developing problems related to the graft such as the development of endoleaks. Endoleaks can cause expansion of the aneurysmal sac, which can potentially lead to rupture. It is for this reason that lifelong surveillance of patients is required to assess the graft and the aneurysmal sac. This article discusses the role of contrast-enhanced ultrasound in the follow-up of patients post-endovascular aneurysm repair. Contrast-enhanced ultrasound is rapidly becoming a powerful, accurate and cost-effective tool to complement computed tomography in the follow-up of endovascular aneurysm repair patients. Real-time imaging of contrast filling into the arterial system means that contrast-enhanced ultrasound is an excellent problem-solving tool, particularly when assessing for the type and anatomy of endoleaks. In some instances, contrast-enhanced ultrasound can detect endoleaks when other modalities are equivocal.

Delayed complication of abdominal aortic stent: a rare complication

We hereby present a case of recurrent abdominal aortic aneurysm due to endoleak to outline complications and secondary intervention strategies post endovascular aneurysm repair.

Surveillance Imaging Following Endovascular Aneurysm Repair

There is a significant risk of complication following endovascular abdominal repair (EVAR), including endoleak, graft translocation, thrombosis, and infection. Surveillance imaging is important for detecting EVAR complication. Surveillance modalities include conventional X-ray, computed tomography, magnetic resonance imaging, ultrasound, and conventional angiography, with inherent advantages and drawbacks to each modality. The authors present common complications following EVAR, and recent advances in the key modalities for surveillance.

Detecting Aortic Graft Complications: A Spectrum of Computed Tomography Findings

Endovascular aneurysm repair (EVAR) is a successful technique as well as an excellent alternative to the surgical management of abdominal aortic aneurysms. EVAR has improved the mortality and morbidity of many patients who would have otherwise suffered greatly from the consequences of abdominal aortic aneurysms. However, EVAR is not without complications. Some complications require lifelong surveillance, whereas others may necessitate immediate surgical intervention. We discuss the various modalities available for the surveillance as well as the common complications that can be seen on computed tomography.

Essentials of endovascular abdominal aortic aneurysm repair imaging: postprocedure surveillance and complications

OBJECTIVE

Lifelong postprocedural imaging surveillance is necessary after endovascular abdominal aortic aneurysm repair (EVAR) to assess for complications of endograft placement, as well as device failure and continued aneurysm growth. Refinement of the surveillance CT technique and development of ultrasound and MRI protocols are important to limit radiation exposure.

CONCLUSION

A comprehensive understanding of EVAR surveillance is necessary to identify life-threatening complications and to aid in secondary treatment planning.

"Sweet spot" for endoleak detection: optimizing contrast to noise using low keV reconstructions from fast-switch kVp dual-energy CT

OBJECTIVE

To assess endoleak detection and conspicuity using low-kiloelectron volt (keV) monochromatic reconstructions of single-source (fast-switch kilovolt [peak]) dual-energy data sets.

METHODS

With approval of the institutional review board, multiphasic dual-energy computed tomographic (CT) scans for aortic endograft surveillance were retrospectively reviewed for 39 patients. Two abdominal radiologists each performed 2 separate reading sessions, at 55-keV and standard 75-keV reconstruction, respectively. The readers tabulated endoleak presence, conspicuity on 1-to-5 scale, and type overall and in arterial and venous phases. Originally, dictated reports in medical records were used as criterion standard.

RESULTS

Original dictations identified 19 endoleaks (9 abdominal and 10 thoracic), 13 of which were type II. The blinded readers (R1 and R2) exhibited good to very good intraobserver and interobserver agreement. Endoleak detection was higher at 55 keV than at 75 keV (sensitivity, 100% (95% confidence interval [CI], 82.4%-100.0%) and 84.2% (95% CI, 60.4-96.6%) at 55 keV vs 79% (95% CI, 54.4-94.0%) and 68.4% (95% CI, 43.5%-87.4%) at 75 keV in venous phase). Further, endoleak conspicuity ratings (where original dictation showed positive leak) were higher at 55 keV than at 75 keV, which was a significant difference for R2 in the overall ratings (P = 0.03) and for both readers in the venous phase ratings (R1, P = 0.01; R2, P = 0.004). There was no difference in endoleak type characterization between the kiloelectron volt levels.

CONCLUSION

Sensitivity for endoleak detection and overall endoleak conspicuity ratings were both higher at 55 keV than 75 keV, favoring the inclusion of a lower-energy monochromatic reconstruction for endoleak surveillance protocols with dual-energy computed tomography.

Management of Endoleaks following Endovascular Aneurysm Repair

Endovascular aneurysm repair (EVAR) has emerged as a viable alternative to open repair for abdominal aortic aneurysms. Endoleaks are a complication unique to EVAR and can occur in up to 25% of patients. In this article, the management of endoleaks following EVAR will be discussed.

DynaCT during EVAR--a comparison with multidetector CT

OBJECTIVES

We have explored the usefulness of an on-table, cross-sectional radiological imaging (DynaCT) in endovascular aortic repair (EVAR). DynaCT images were compared to images from a regular multidetector (16 slice) CT. In the comparison, we tested the accordance of firstly 5 relevant clinical measurements and secondly the visibility of 9 anatomical areas in the two different types of images. This imaging was carried out in addition to the usual angiographic imaging. DESIGN, MATERIAL AND METHOD: 20 patients with infrarenal abdominal aortic aneurysm (AAA) were prospectively enrolled in the study. We compared Images from DynaCT with two different doses of contrast medium to MDCT-images in two different ways. Firstly relevant arterial diameters and lengths and secondly, 9 anatomical areas were evaluated regarding visibility which was scored on a 4-point scale.

RESULTS

There were no significant differences in the measured arterial diameters and lengths. MDCT had a significantly higher visibility score than both DynaCT investigations. However, with the highest contrast medium dose we found acceptable diagnostic quality in 78-94% of the cases for 8 of the 9 investigated anatomical areas.

CONCLUSION

Our findings indicate that on-table DynaCT are of sufficient quality to give relevant information of arterial measurements, needed in endovascular repair of infrarenal aortic aneurysms.

Surveillance of patients post-endovascular aneurysm repair

Endovascular aneurysm repair (EVAR) is increasingly being employed as an alternative to open surgical repair for patients with abdominal aortic aneurysms. The surveillance of patients post-EVAR has traditionally been carried out with regular computed tomographic scans which have in part been responsible for the high costs associated with this procedure. Duplex has been proposed as an alternative, but researchers have so far been unable to devise a standardised protocol for this surveillance. This review aims to provide a clear understanding of currently employed imaging modalities and discuss future surveillance possibilities for this patient group.

Cross-Sectional Imaging Studies: What Can We Learn and What Do We Need to Know?

Rapid, noninvasive imaging approaches can provide novel diagnostic information and, when effectively interpreted and implemented in a therapeutic strategy, can simplify procedures. Endovascular therapy of thoracic and abdominal aortic disease represents a dramatic shift in treatment of thoracoabdominal aortic disease, but one that requires a change in the knowledge base regarding both the morphology and pathophysiology of aortic disease and the interaction with interventional devices. As a result, the demands on cross-sectional imaging have increased commensurately with the complexity of the therapeutic options, but advances in cross-sectional imaging have kept pace. Current computed tomography (CT) and magnetic resonance imaging (MRI) technologies provide detailed morphologic assessment, and are advancing rapidly into more sophisticated physiologic evaluation of aortic disease. These advances may more effectively triage patients to appropriate therapy, or exclude patients from unnecessary invasive procedures. The information gleaned from CT and MRI studies is critical for the vascular surgeon who wants to identify appropriate vascular territories for intervention, plan a detailed approach, and develop sophisticated surveillance strategies.