Surgical or Endovascular Therapy of Abdominal Penetrating Aortic Ulcers and Their Natural History: A Systematic Review

Editor's Choice -- European Society for Vascular Surgery (ESVS) 2024 Clinical Practice Guidelines on the Management of Abdominal Aorto-Iliac Artery Aneurysms

OBJECTIVE

The European Society for Vascular Surgery (ESVS) has developed clinical practice guidelines for the care of patients with aneurysms of the abdominal aorta and iliac arteries in succession to the 2011 and 2019 versions, with the aim of assisting physicians and patients in selecting the best management strategy.

METHODS

The guideline is based on scientific evidence completed with expert opinion on the matter. By summarising and evaluating the best available evidence, recommendations for the evaluation and treatment of patients have been formulated. The recommendations are graded according to a modified European Society of Cardiology grading system, where the strength (class) of each recommendation is graded from I to III and the letters A to C mark the level of evidence.

RESULTS

A total of 160 recommendations have been issued on the following topics: Service standards, including surgical volume and training; Epidemiology, diagnosis, and screening; Management of patients with small abdominal aortic aneurysm (AAA), including surveillance, cardiovascular risk reduction, and indication for repair; Elective AAA repair, including operative risk assessment, open and endovascular repair, and early complications; Ruptured and symptomatic AAA, including peri-operative management, such as permissive hypotension and use of aortic occlusion balloon, open and endovascular repair, and early complications, such as abdominal compartment syndrome and colonic ischaemia; Long term outcome and follow up after AAA repair, including graft infection, endoleaks and follow up routines; Management of complex AAA, including open and endovascular repair; Management of iliac artery aneurysm, including indication for repair and open and endovascular repair; and Miscellaneous aortic problems, including mycotic, inflammatory, and saccular aortic aneurysm. In addition, Shared decision making is being addressed, with supporting information for patients, and Unresolved issues are discussed.

CONCLUSION

The ESVS Clinical Practice Guidelines provide the most comprehensive, up to date, and unbiased advice to clinicians and patients on the management of abdominal aorto-iliac artery aneurysms.

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.

Systematic Review on Abdominal Penetrating Atherosclerotic Aortic Ulcers: Outcomes of Endovascular Repair

PURPOSE

To systematically review existing evidence on outcomes of endovascular repair of abdominal atherosclerotic penetrating aortic ulcers (PAUs).

MATERIAL AND METHODS

Cochrane Central Registry of Registered Trials (CENTRAL), MEDLINE (via PubMed), and Web of Science databases were systematically searched. The systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis protocol (PRISMA-P 2020). The protocol was registered in the international registry of systematic reviews (PROSPERO CRD42022313404). Studies reporting on technical and clinical outcomes of endovascular PAU repair in 3 or more patients were included. Random effects modeling was used to estimate pooled technical success, survival, reinterventions, and type 1 and type 3 endoleaks. Statistical heterogeneity was assessed using the I² statistic. Pooled results are reported with 95% confidence intervals (CIs). Study quality was assessed using an adapted version of the Modified Coleman Methodology Score.

RESULTS

Sixteen studies including 165 patients with a mean/median age ranging from 64 to 78 years receiving endovascular therapy for PAU between 1997 and 2020 were identified. Pooled technical success was 99.0% (CI: 96.0%-100%). In all, 30-day mortality was 1.0% (CI: 0%-6.0%) with an in-hospital mortality of 1.0% (CI: 0.0%-13.0%). There were no reinterventions, type 1, or type 3 endoleaks at 30 days. Median/mean follow-up ranged from 1 to 33 months. Overall, there were 16 deaths (9.7%), 5 reinterventions (3.3%), 3 type 1 (1.8%), and 1 type 3 endoleak (0.6%) during follow-up. The quality of studies was rated low according to the Modified Coleman score at 43.4 (+/- 8.5) of 85 points.

CONCLUSION

There is low-level evidence on outcomes of endovascular PAU repair. While in the short-term endovascular repair of abdominal PAU seems safe and effective, mid-term and long-term data are lacking. Recommendations with regard to treatment indications and techniques in asymptomatic PAU should be made cautiously.

CLINICAL IMPACT

This systematic review demonstrated that evidence on outcomes of endovascular abdominal PAU repair is limited. While in the short-term endovascular repair of abdominal PAU seems safe and effective, mid-term and long-term data are lacking. In the context of a benign prognosis of asymptomatic PAU and lacking standardization in current reporting, recommendations with regard to treatment indications and techniques in asymptomatic PAUs should be made cautiously.

Midterm results of complicated penetrating abdominal aortic ulcer treated by aortobi-iliac endograft and embolization

BACKGROUND

Penetrating aortic ulcer (PAU) is determined by atherosclerotic degeneration of the tunica media with disruption of the intima. Usually it is detected in the thoracic aorta, with few series describing an abdominal location. The aim of the study was to report early and late outcomes of the endovascular repair of complicated infrarenal abdominal PAU (a-PAU) by aortobi-iliac endograft and embolization.

METHODS

Data from all complicated a-PAU submitted to endovascular repair by aortobi-iliac endograft (Cook-Zenith Alpha) between 2016 and 2021 (February) were analyzed. The a-PAU coil embolization was performed to decrease the risk of persistent type II endoleak whenever possible. Complicated a-PAU were defined according with the presence of symptoms, aortic rupture, or saccular or pseudo-aneurysm. Technical success, 30-day morbidity and mortality, and reinterventions were assessed as early outcomes. Survival, endoleaks, and freedom from reinterventions were evaluated during follow-up.

RESULTS

Of 1153 endovascular aortic procedures, 45 cases (4%) of complicated a-PAU were identified. Fourteen cases (31%) were managed in urgent setting (symptoms, n = 10 [22%]; shock, n = 4 [9%]). The median diameter of a-PAU was 49 mm (interquartile range, 14 mm). Thirteen patients (29%) had severe femoral or iliac access (angle >90°, circumferential calcification [>50%], hemodynamic iliac stenosis or obstruction, an external iliac artery diameter of less than 7 mm, or a previous femoral surgical graft). The a-PAU embolization was performed in 30 cases (67%). Technical success was achieved in all patients. Postoperative cardiac, pulmonary and renal morbidity occurred in one (2%), two (4%), and eight (18%) patients, respectively. Two patients (4%) required reintervention within 30 days for access related complications. The 30-day mortality was 2%. At a median follow-up of 24 months (interquartile range, 18 months), no type I or III endoleaks, iliac leg occlusion, or graft infection occurred and no patient required late reinterventions; the 36-month survival rate was 72%. No a-PAU enlarged or ruptured during follow-up.

CONCLUSIONS

Endovascular repair of complicated a-PAU by a low-profile aortobi-iliac endograft and embolization is safe and effective. Excellent technical results are reported even in challenging anatomic features. Midterm clinical results are satisfactory in terms of aortic-related complications or mortality, freedom from reintervention, and survival.

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.

Diagnosis and Management of Acute Aortic Syndromes: Dissection, Penetrating Aortic Ulcer, and Intramural Hematoma

PURPOSE OF REVIEW

Acute aortic syndromes, including aortic dissection, intramural hematoma, and penetrating aortic ulcer, are a group of highly morbid, related pathologies that are defined by compromised aortic wall integrity. The purpose of this review is to summarize current management strategies for acute aortic syndromes.

RECENT FINDINGS

All acute aortic syndromes have potential for high morbidity and mortality and must be quickly identified and managed with the appropriate algorithm to prevent suboptimal outcomes. Recent trials suggest that TEVAR is increasingly useful in stabilizing pathology of the descending thoracic aorta but when possible should be applied in a delayed fashion and with limited coverage to minimize neurologic complications. Treatment for acute aortic syndrome is frequently dictated by the anatomic location and extent of the wall compromise as well as patient comorbidities. Therapy is often individualized and often includes some combination of medical, procedural, and surgical intervention.

Isolated Ruptured Paravisceral Penetrating Aortic Ulcers

BACKGROUND

The goal of this study is to investigate the clinical presentation, treatment options, and outcomes of the patients with isolated ruptured paravisceral penetrating aortic ulcers (PV-PAU).

METHODS

All patients presenting with acute aortic syndrome from 2015 to 2020 were screened, of which patients with isolated ruptured PV-PAU were included in this retrospective study. Study endpoints were the assessment of treatment options, technical success, and clinical outcome. Outcome measures included major perioperative complications and mortality.

RESULTS

Sixteen patients (11 men; median age 68; IQR 60 - 75 years) presented with isolated ruptured PV-PAU were included in this study. The median follow-up was 25 months (range 1 - 51). Ruptured PV-PAUs represented 12.3% of the ruptured aortic aneurysms in all locations. PV-PAUs were found in segment A (n = 8, 50%), segment B (n = 5, 31%), and segment C (n = 3, 19%). PV-PAUs showed a mean protrusion distance of 27±10 mm, a mean neck diameter of 21 ± 7 mm, and maximal aortic diameter of 50 ± 11 mm. Five patients (31%) showed hemodynamic instability on admission and needed intense fluid resuscitation. Of those, 2 patients needed urgent laparotomy with a fast transabdominal supraceliac aortic clamping, one needed an aortic balloon occlusion to obtain rapid aortic control. The open aortic repair was the most frequently performed surgery (11/16, 69%), followed by hybrid procedures (3/16) and parallel graft chimney technique (2/16). Two patients died during the follow-up, calculating for in-hospital and 1-year mortality rates of 6 - 12%, respectively. The postoperative morbidity rate was 31%. Postoperative complications included acute renal failure (31%), pneumonia (25%), and 1case of ischemic colitis (6%). No spinal cord ischemia was reported.

CONCLUSIONS

Ruptured PV-PAU is a rare and challenging diagnostic and therapeutic entity. Open aortic repair seems to be a reliable option in treating patients with isolated ruptured PV-PAUs. Hybrid procedures and parallel stent-graft techniques can only be used in selected patients.

Unibody design for aortic disease with a narrow aortic bifurcation: tips and tricks for success

Background

Surgical management of patients with abdominal aortic diseases associated with distal narrowing is a challenging situation.

Objectives

To evaluate outcomes of unibody bifurcated endovascular stent graft repair.

Methods

This is a retrospective, observational, multi-institutional database study of a cohort of consecutive cases, approved by the local Ethics Committee. Records were reviewed of patients diagnosed from 2010 to 2020 with “shaggy” aorta, saccular aneurysm, penetrating aortic ulcer, and isolated aortic dissection located in the infrarenal abdominal aorta. All patients were treated with a unibody bifurcated stent graft. Main outcomes were technical success, procedure complications, long-term patency, and mortality in the follow-up period up to 5 years. Data on demographics, comorbidities, surgical management, and outcomes were analyzed.

Results

Twenty-three patients were treated with unibody bifurcated stent graft repair, including 7 cases of “shaggy” aorta, 3 isolated dissections of the abdominal aorta, 4 penetrating aortic ulcers, and 9 saccular aneurysms. Immediate technical success was achieved in 100% of cases. At follow-up, all stent grafts remained patent and there were no limb occlusions. The patients were symptom-free and reported no complications related to the procedure. There were 5 deaths during the follow-up period (median= 4 years), but none were related to the procedure and there were no aorta-related deaths.

Conclusions

The present study shows that unibody bifurcated stent grafting is safe and effective in this group of patients with narrow distal abdominal aorta and complex aortic pathology. The results were similar for both infrarenal aortic aneurysms and aorto-iliac atherosclerotic disease.

Multicenter Experience With Large Diameter Balloon-Expandable Stent-Grafts for the Treatment of Infrarenal Penetrating Aortic Ulcers

Purpose

To describe the use of large-diameter balloon-expandable stent-grafts (BeGraft aortic stent-graft, Bentley InnoMed GmbH, Hechingen, Germany) in the treatment of infrarenal penetrating aortic ulcer (iPAU).

Materials and Methods

Retrospective analysis of patients undergoing endovascular treatment with the BeGraft aortic stent-graft in 8 European centers from January 2017 to October 2020. Demographics, perioperative data, and midterm outcomes were collected. Endpoints of the study were technical feasibility, early mortality, and morbidity.

Results

A total of 40 patients were included. The mean age was 73.9±7.05 years and 63.2% were male. Indications for treatment included size and morphology (65%), presence of symptoms (29.5%), and contained ruptures (5.5%). Urgent treatment was performed in 5% of cases. Technical success was 97.5%. Median operation time was 58 minutes (19–170 minutes), with 27.5% of patients having additional procedures during the main intervention (1 additional repair with a C-TAG (W.L. Gore & Associates, Inc, Flagstaff, AZ, USA) thoracic endoprosthesis, 5 covered endovascular reconstruction of aortic bifurcation procedures, 3 extensions with proximal cuffs, and 2 percutaneous angioplasties of the common iliac arteries). Percutaneous femoral access was used in 72.5%, while groin cut-down was performed in 27.5%. Repair was successful with only 1 stent in 45% of cases, while 37.5% required 2 stents and nearly 17.5% required 3/4 stent-grafts. The 30-day mortality was 0%, with a 2.5% reintervention rate (1 patient required evacuation of an intra-abdominal hematoma). Median follow-up was 13.9 months (2–39 months), during which no vascular-related reinterventions or deaths were reported. In 4 patients, a type II endoleak was observed. No cases of graft migration, thrombosis, or stent-fracture were observed.

Conclusions

The treatment of iPAU with the BeGraft aortic stent-graft in a selective patient group is feasible with low rate of perioperative morbidity and mortality. Balloon-expandable stent-grafts offer the option to repair iPAUs with a shorter coverage of the aorta using low-profile sheath, that enables treatment in the presence of calcified access vessels and small diameter aortic bifurcations.

The Management of Patients With Penetrating Aortic Ulcers: A Systematic Review

BACKGROUND

Penetrating aortic ulcers (PAUs) are an entity within acute aortic syndrome. They often remain undiagnosed and are found incidentally or when they become symptomatic. Management is currently guided by clinical judgment. This review aims to identify indications for treatment and inform management.

METHODS

We searched PubMed for studies on the management of PAUs. The outcome measures were mortality, progression and resolution of symptoms.

RESULTS

This review incorporates 27 studies involving 1356 patients with PAU. Data was available regarding symptoms for 1213 patients (494 symptomatic, 719 asymptomatic). Overall late mortality for PAUs was found to be higher than 30-day mortality. Early mortality was higher for symptomatic patients as compared to those with asymptomatic PAUs. Early mortality was lowest for PAUs treated with endovascular interventions (5%), followed by PAUs managed medically and highest following open surgical management. Indications for treatment included symptoms, progression/instability, aortic diameter >5 cm, concomitant aortic pathology or pleural effusion. 13% of patients managed conservatively at initial presentation demonstrated progression and were considered for intervention subsequently. 9% of patients required reintervention after initial endovascular surgery.

CONCLUSION

Endovascular treatment, if anatomically suitable, should be considered as first line treatment for symptomatic PAUs. Patients with asymptomatic PAUs, if associated with high-risk features such as PAU diameter >20 mm, PAU depth >10 mm, aortic diameter >42 mm, concomitant pathology, morphological change or an infective etiology, should also be considered for intervention. Small asymptomatic PAUs with no high-risk features may be managed conservatively but must undergo regular surveillance.

Natural History, Clinical Significance, and the Role of Vascular Referral in the Management of Penetrating Ulcers of the Abdominal Aorta

BACKGROUND

Penetrating ulcers of the abdominal aorta (PUAA) are an increasingly common finding on abdominal imaging studies; however, their significance and natural history are not well described. This study's objective was to analyze the demographics, presentation, and outcomes of patients with a radiographic diagnosis of PUAA.

MATERIALS AND METHODS

Patients at our tertiary referral center were identified for inclusion based on a search for the term "penetrating ulcer" in abdominal computed tomography and magnetic resonance imaging reports between January 2014 and December 2017. Patients' electronic medical records were retrospectively reviewed to determine baseline medical characteristics, imaging indication, and subsequent clinical course, interventions, and outcomes. Aortic diameters and ulcer depths were measured by a single observer on initial and follow-up imaging to assess for association with concomitant aortic pathology, evolving aortic disease, and ulcer progression, defined as increase in depth of ≥ 1 mm. Statistical analysis was performed using STATA 16 (College Station, TX: StataCorp LLC), and a threshold P-value of <0.05 was set for significance.

RESULTS

Ninety-two patients with PUAA were identified; 57 (62%) were male. The mean age at diagnosis was 79.3 years, and comorbidities included hypertension (74%), hyperlipidemia (65%), and malignancy (34%). The most common indication for imaging was chest, back, or abdominal pain (19%). On initial imaging, the mean ulcer depth was 1 cm (range from 0.2 cm to 3.4 cm). Concomitant abdominal aortic dilation ≥ 3 cm was found in 34 (37%) patients. Thirty-six (39%) patients had a vascular surgery consultation immediately after radiographic diagnosis. Follow-up axial imaging was performed on 27 (29%) untreated patients. The overall sample's mean ulcer depth remained essentially unchanged from initial measurement (P = 0.99); however, 14 (52%) patients with follow-up imaging were found to have increased overall aortic diameter. Of the total 92 patients, 9 (10%) underwent an endovascular abdominal aortic intervention during the review period: 2 for symptomatic PUAA and the remainder for progression of concomitant aneurysmal disease. All-cause mortality was 5% during the mean follow-up period of 21.9 months (range 0 to 72.5 months). Of the patients lost to follow-up, 61% did not receive vascular referral after initial diagnosis.

CONCLUSIONS

PUAA are typically incidental findings identified in elderly, comorbid patients undergoing imaging for an unrelated indication. Although isolated findings of asymptomatic PUAA rarely require surgical intervention, these patients we argue would benefit from vascular surgery referral for long-term follow-up and interval imaging to assess for disease progression and concomitant aortic degeneration, which may necessitate repair. In addition, we observed that most of those patients lost to follow-up did not receive vascular consultation, suggesting that lack of involvement of vascular specialists at the time of diagnosis is a missed opportunity to secure appropriate follow-up and management.

Intramural hematoma and penetrating atherosclerotic ulcers of the aorta: uncertainties and controversies

The natural histories of intramural hematoma (IMH) and penetrating atherosclerotic ulcer (PAU) are highly variable as they may progress to aneurysm formation, rupture, or dissection, or even resolve, in the specific case of IMH. Imaging plays an increasingly important role in clinical and surgical management of IMH and PAU. In contrast to ulcer-like projections, images of intramural blood pools have not been widely reported in CT studies of patients with IMH. Understanding the imaging characteristics and the natural course of each of these entities would help clinicians and surgeons to identify patients at greatest risk for bad prognosis and may improve outcomes. This paper discusses the pathophysiology of these entities, the controversies regarding their natural history, and the prognostic factors that should be identified in CT scans.

Acute non-traumatic disease of the abdominal aorta

Acute pathology in the abdominal aorta is associated with significant morbidity and mortality. The most feared complication of abdominal aortic disease is acute rupture in the setting of atherosclerotic abdominal aortic aneurysm. Although frank rupture often is easily diagnosed on CT, other findings such as a hyperattenuating crescent, discontinuous intimal calcium, and draping of the aorta are subtle signs of aneurysm instability. A true aneurysm should be distinguished from a rapidly growing, saccular pseudoaneurysm in the setting of infectious aortitis, as treatment strategy differs. Acute aortic syndrome involving the abdominal aorta, such as dissection and intramural hematoma, often is an extension of thoracic aortic disease, whereas penetrating atherosclerotic ulcers occasionally involve only the abdominal aorta. The goal of treating acute aortic pathology is to repair and prevent rupture, as well as restore and maintain perfusion of the lower extremities, kidneys, and mesentery. However, both open and endovascular repair of the abdominal aorta may become acutely complicated, resulting in compromise of these goals. Examples include aortoenteric fistula, endoleak, anastomotic pseudoaneurysm, graft infection, and thrombosis or kinking of a stent graft resulting in ischemia of the limbs and mesentery.

Abdominal aortic aneurysms revisited: MDCT with multiplanar reconstructions for identifying indicators of instability in the pre- and postoperative patient

Rupture of an abdominal aortic aneurysm is commonly a fatal event. Multidetector computed tomographic (CT) signs of frank aortic rupture are usually readily apparent and widely understood. However, diagnosing an impending aortic rupture on the basis of imaging findings can prove more difficult. CT is the primary modality used for serial imaging in patients with aortic aneurysm and may show findings indicative of aortic instability. Therefore, it is critical that radiologists be familiar with the CT findings of aortic instability to avert the potential complications of hemorrhage, end organ or limb ischemia, and death. Various preoperative CT indicators have been previously described in both research investigations and review articles. A large baseline aneurysm size and a rapid increase in size over time are associated with a higher risk for rupture. The importance of obtaining accurate measurements with multiplanar reconstructions and the role of new semiautomated tools for obtaining accurate, reproducible measurements are discussed. Additional CT findings that reflect aortic aneurysm instability include luminal expansion with lysis of thrombus, intramural hemorrhage (ie, the crescent sign), periaortic hemorrhage, a penetrating atherosclerotic ulcer, and contained rupture (ie, the draped aorta sign). After open or endovascular aneurysm repair, CT is routinely used to monitor for graft complications. In this setting, radiologists should understand that the presence of an endoluminal stent or surgical graft does not preclude aortic rupture. Online supplemental material is available for this article.