Staged repair of a ruptured thoracoabdominal aortic aneurysm: a case report.

BACKGROUND: A ruptured thoracoabdominal aortic aneurysm (rTAAA) represents a considerable challenge for surgeons. To date, endovascular procedures have not been able to completely replace open repair when debranching is required. CASE PRESENTATION: A 73-year-old man was admitted to our hospital after complaining of left lateral abdominal pain. Enhanced computed tomography revealed a left retroperitoneal hematoma and a large, ruptured Crawford type IV TAAA. We first performed emergency resuscitative surgery to close the lacerated foramen. A graft replacement was performed 1 month after the initial surgery when the patient had stabilized. At 5 years postoperatively, neither occlusion nor anastomotic pseudoaneurysm was noted on computed tomography. CONCLUSIONS: We provide an update on the perioperative management of patients undergoing open rTAAA repair. This procedure can be considered to ensure complete repair of an rTAAA.

The causal relationship between thoracic aortic aneurysm and immune cells: a mendelian randomization study.

One of the pathogenic causes of thoracic aortic aneurysm (TAA), a dangerous vascular condition that can cause aortic rupture, is autoimmune disorders. Currently, immune cell clustering is becoming more and more refined, and the specific immune cell phenotypes involved are yet unknown. Here, we want to clarify the causal link between TAA risk and 731 immune cell traits. There was a Mendelian randomization analysis (MR). We discovered that the presence of TAA led to an increase in CD45 on CD33- HLA-DR- myeloid cells, an increase in CD45 on natural killer cells, and a decrease in FSC-A on granulocytes after applying FDR correction. Our research also revealed a strong correlation between the incidence of TAA and an increase in immune cells with CD3 on CD39+ CD4+, and CD25 on IgD- CD27- phenotypes. Through genetic techniques, our research has shown the intimate relationship between immune cells and TAA, offering direction for future clinical investigations.

Aorto-atrial tunnel arising from sinus of Valsalva aneurysm in a young female.

A young female patient presented with complaints of breathlessness and palpitations since 2 years. On clinical examination, there was a loud continuous murmur at the right sternal border.Transthoracic echocardiography and colour Doppler showed a tunnel-like structure originating from the aneurysmal right coronary sinus and opening into the right atrium with left to right shunt. Coronary angiography revealed a large tunnel beginning in right coronary sinus and terminating in the right atrium and right coronary artery (RCA) was seen originating from the tunnel. Cardiac catheterisation revealed normal pulmonary artery pressure. CT and 3D-reconstructed images delineated the extracardiac course of the tunnel.Various treatment modalities including percutaneous transcatheter approach and surgical treatment were taken into consideration, but because of the close proximity of RCA from the tunnel opening, surgical closure was preferred.

Endovascular Repair of Ruptured Aortic Aneurysm: A Single-Center Experience.

OBJECTIVE: Aortic rupture is a rare and catastrophic emergency. Prompt diagnosis and treatment are the primary determinants of mortality. During follow-up, the majority of patients who have been effectively treated die from hypovolemic shock and multiorgan failure. This article describes the clinical and procedural details of sixteen patients with ruptured aortic aneurysms treated endovascularly. In addition, it discusses the main factors contributing to the mortality of these patients. METHOD: Patients who underwent endovascular treatment for acute aortic rupture at our center from October 2016 to March 2023 were included in this retrospective study. RESULTS: A total of 16 patients underwent endovascular aneurysm repair (EVAR) or thoracic endovascular aneurysm repair (TEVAR) for acute aortic rupture. The patients' mean age was 73.06 years (range: 52-92), and 15 of them were male. The ruptures occurred in the abdominal aortic aneurysm in ten patients, in thoracic aortic aneurysm in three patients, in the isolated iliac artery aneurysm in two patients, and there was one case of non-aneurysmal aortic rupture. In our series, patients who presented with an impending, self-limited rupture and stable hemodynamic status had good prognostic outcomes. However, eight patients died due to multiorgan failure, hemorrhagic shock, disseminated intravascular coagulopathy, renal failure, or abdominal compartment syndrome. These patients generally had poor admission vital signs and low hemoglobin values. The most critical determinants for the success of the procedure are promptly stopping the bleeding, avoiding general anesthesia, and opting for blood product replacement instead of fluid replacement. CONCLUSION: Each patient with ruptured aortic aneurysm should be managed according to the patient's hemodynamics at presentation, the size of the aneurysm, the suitability for percutaneous procedure, logistical factors, and the operator-center's experience.

Significant thrombus in saccular aneurysm in a patient with polycythemia: a case report.

BACKGROUND: Morphologically, the risk of aortic aneurysm rupture is mainly evaluated based on its type (e.g., fusiform or saccular) and diameter. Based on the finite element analysis, peak wall stress has been identified as a more sensitive and specific predictor of rupture in recent years. Moreover, in finite analysis, the neck of aneurysm is the highest peak wall stress and is associated with the rupture point. CASE PRESENTATION: A saccular aortic aneurysm (84 mm) was incidentally detected during preoperative examination for chronic empyema in a 74-year-old male patient with a history of polycythemia. Aortic arch graft replacement using an open stent was performed. CONCLUSIONS: Morphologically, this case was associated with a very high risk of rupture; nevertheless, it did not rupture. In this case, a mural thrombus (likely formed due to polycythemia) covered the neck of aneurysm that is experiencing the highest peak wall stress and is associated with the rupture point. The mural thrombus decreased peak wall stress and could reduce the risk of rupture even for huge saccular aneurysms. Furthermore, the mural thrombus was fully occupied in aneurysms, such as during coil embolization. Thus, polycythemia could decrease the risk of rupture of huge saccular aneurysms.

Right Sinus of Valsalva Aneurysm Rupturing into the Right Atrium and Dissecting into the Interventricular Septum.

The right sinus of the Valsalva aneurysm (SVA) rupturing into the right atrium (RA) and dissecting into the interventricular septum (IVS) is rare. The disease can be definitively diagnosed using two-dimensional (2D) echocardiography and color Doppler ultrasonography. Real-time biplane imaging and three-dimensional (3D) echocardiography offer new perspectives for viewing and diagnosing this disease.

A retrospective cohort study of incidental abdominal aortic aneurysms on routine abdominal computed tomography scans in Te Tairawhiti (2018-2019).

AIM: Ruptured abdominal aortic aneurysm (rAAA) is associated with a high mortality rate which, is especially significant in rural and provincial regions. In Aotearoa New Zealand, Maori experience higher rates of AAA and worse overall medium-term survival following AAA repair. This study aimed to understand the prevalence of incidental AAA on routine abdominal computed tomography (CT) scans over 12 months. METHOD: A retrospective review of all abdominal CT scans performed on patients ≥50 years at Gisborne Hospital between 1 December 2018-1 December 2019 was performed. RESULTS: A total of 811 scans were reviewed, with 42 incidental AAA detected (5.2%). The majority of incidental AAA were in males aged ≥65 (65.8%), with a higher prevalence for Maori compared to New Zealand European (NZE) (16.2% vs 8.1%, p=0.052). This pattern was also seen in females, aged ≥65 (10.9% in Maori vs 3.8% in NZE, p=0.047). CONCLUSION: The detection of AAA on routine abdominal CT scans appears to be a useful adjunct in lieu of targeted AAA screening in our region. A high prevalence of incidental AAA (5.2%) over 12 months, with a significantly higher prevalence noted in Maori males and females ≥65 years (16.2% and 10.9%), was observed.

[Surgical Treatment for Ruptured Thoracoabdominal Aneurysm Following Descending Aortic Replacement with Double Barrel Anastomosis].

A 75-year-old woman was diagnosed with type B acute aortic dissection 14 years ago and 3-channeled aortic dissection 7 years ago. She received total arch replacement 6 years ago and descending aortic replacement with double barrel anastomosis technique for distal anastomosis 5 years ago. Computed tomography( CT) revealed giant thyroid tumor and thoracoabdominal aortic aneurysm( 58 mm in diameter). She suffered from back pain during her follow-up period. CT revealed ruptured thoracoabdominal aortic aneurysm. First, the false lumen of descending aorta was closed by thoracic endovascular aortic repair, and then thoracoabdominal aortic replacement was performed uneventfully.

Aortic rupture following acute aortitis in a patient with head and neck carcinoma treated with nivolumab: a rare but severe immune-related adverse event.

INTRODUCTION: Immune-related adverse events (irAEs) due to immune checkpoint inhibitors may lead to discontinuation and treatment-related death. Acute aortitis is a rare but severe irAE. CASE PRESENTATION: A 67-year-old man with recurrent lower gingival carcinoma received nivolumab therapy. Twenty-three months later, he experienced chest compression, which resulted in syncope. Following a whole-body computed tomography (CT) scanning, which revealed diffuse thickening of the aorta, and systemic assessments of the causes of aortitis, he was diagnosed with acute aortitis due to irAE. Nivolumab discontinuation and oral steroids improved CT findings. However, 11 months after nivolumab discontinuation, he developed an aortic aneurysmal rupture. Endovascular aortic repair rescued him. A durable anti-cancer response was still observed 4 months after the aortic rupture. CONCLUSION: Although severe irAE, such as acute aortitis, occurred, the patient may still achieve a durable response. A broad examination and prompt treatment of irAE can help improve the patient's survival.

Prehospital point-of-care ultrasound in ruptured abdominal aortic aneurysms-a retrospective cohort study.

BACKGROUND: Patients with ruptured abdominal aortic aneurysm (rAAA) require immediate vascular treatment to survive. The use of prehospital point-of-care ultrasound (POCUS) may support clinical assessment, correct diagnosis, appropriate triage and reduce system delay. The aim was to study the process of care and outcome in patients receiving prehospital POCUS versus patients not receiving prehospital POCUS in patients with rAAA, ruptured iliac aneurysm or impending aortic rupture. METHODS: We performed a retrospective cohort study in patients diagnosed with rAAA in the Central Denmark Region treated by a prehospital critical care physician from 1 January 2017 to 31 December 2021. Performance of prehospital POCUS was extracted from the prehospital electronic health records. System delay was defined as the time from the emergency phone call to the emergency medical service dispatch centre until the start of surgery. Data on patients primary hospital admission to a centre with/without vascular treatment expertise, treatments and complications including death were extracted from electronic health records. RESULTS: We included 169 patients; prehospital POCUS was performed in 124 patients (73%). Emergency surgical treatment was performed in 71 patients. The overall survival in the POCUS group was 39% versus 16% in the NO POCUS group (hazard ratio (HR) (95% 0.60, 95% CI: 0.41-0.89, p = .011). In the POCUS group 99/124 (80%) were directly admitted to a vascular surgical centre versus 25/45 (56%) in the NO POCUS, RD 24% (95% CI: 8-40)), (p = .002). In the POCUS group, system delay was a median of 142 minutes (interquartile range (IQR) 121-189) and a median of 232 minutes (IQR 166-305) in the NO POCUS group (p = .006). In a multivariable analysis incorporating age, sex, previously known rAAA, and typical clinical symptoms of rAAA, the HR for death was 0.57, 95% CI 0.38-0.86 (p = .008) favouring prehospital POCUS. CONCLUSIONS: Prehospital POCUS was associated with reduced time to treatment, higher chance of operability and significantly higher 30-day survival in patients with rAAA, ruptured iliac aneurysm or impending rupture of an AAA in this retrospective study. Residual confounding cannot be excluded. This study supports the clinical relevance of prehospital POCUS of the abdominal aorta.

A 20-Year Analysis of Ruptured Abdominal Aortic Aneurysm Outcomes and Associated Factors in Korea.

BACKGROUND: Unlike western countries, which have reported distinct decreases in incidence of ruptured abdominal aortic aneurysm (rAAA) over the last few decades, epidemiologic studies in Korea have not shown significant changes in incidence or mortality of rAAA. The purpose of this study was to analyze the changes in rAAA treatment outcomes and various associated risk factors over the past 2 decades. METHODS: A 20-year retrospective multicenter review for rAAA cases from the period of January 2000 to December 2020 was undertaken. Preoperative, intraoperative and postoperative clinical data were extracted for patients diagnosed with rAAA. For analysis, outcomes from the early era, defined as patients treated between January 1, 2000, and December 31, 2010, were compared with outcomes from the late era, defined as patients treated between January 1, 2011, and December 31, 2020. RESULTS: The total in-hospital mortality was 34.1% in the early era compared to 44.8% in the late era. Patients in the late era were older than those in the early era (75.2 ± 10.3 years vs. 70.3 ± 8.9 years; P = 0.009). Treatment with rAAA endovascular aneurysm repair increased from 2.3% in early to 13.8% in late era (P = 0.031). In the early era, more patients were operated by experienced surgeons than the late era (78.1% vs. 45.9%; P = 0.002). The emergency room to operating room time did not show improvement over the 20 years. CONCLUSIONS: The results indicate that mortality rate of rAAA in Korea has not changed over the last 2 decades. The study suggests the need for national preventive strategies, improved systemic coordination, and potential centralization of vascular services to enhance survival rates for rAAA.

Identification of abdominal aortic aneurysm subtypes based on mechanosensitive genes.

BACKGROUND: Rupture of abdominal aortic aneurysm (rAAA) is a fatal event in the elderly. Elevated blood pressure and weakening of vessel wall strength are major risk factors for this devastating event. This present study examined whether the expression profile of mechanosensitive genes correlates with the phenotype and outcome, thus, serving as a biomarker for AAA development. METHODS: In this study, we identified mechanosensitive genes involved in AAA development using general bioinformatics methods and machine learning with six human datasets publicly available from the GEO database. Differentially expressed mechanosensitive genes (DEMGs) in AAAs were identified by differential expression analysis. Molecular biological functions of genes were explored using functional clustering, Protein-protein interaction (PPI), and weighted gene co-expression network analysis (WGCNA). According to the datasets (GSE98278, GSE205071 and GSE165470), the changes of diameter and aortic wall strength of AAA induced by DEMGs were verified by consensus clustering analysis, machine learning models, and statistical analysis. In addition, a model for identifying AAA subtypes was built using machine learning methods. RESULTS: 38 DEMGs clustered in pathways regulating 'Smooth muscle cell biology' and 'Cell or Tissue connectivity'. By analyzing the GSE205071 and GSE165470 datasets, DEMGs were found to respond to differences in aneurysm diameter and vessel wall strength. Thus, in the merged datasets, we formally created subgroups of AAAs and found differences in immune characteristics between the subgroups. Finally, a model that accurately predicts the AAA subtype that is more likely to rupture was successfully developed. CONCLUSION: We identified 38 DEMGs that may be involved in AAA. This gene cluster is involved in regulating the maximum vessel diameter, degree of immunoinflammatory infiltration, and strength of the local vessel wall in AAA. The prognostic model we developed can accurately identify the AAA subtypes that tend to rupture.

Total arch replacement via single upper hemisternotomy approach for aortic aneurysm in syphilis: Case report.

RATIONALE: Syphilitic aortic aneurysm is a relatively rare type of cardiovascular syphilis. A small number of patients with syphilitic aortic aneurysms will be accompanied by aortic regurgitation and coronary stenosis. Apart from aortic rupture or dissection, syphilitic aortic aneurysm often causes associated vascular disorders, including left common carotid artery, innominate artery, and celiac artery stenosis or obstruction. PATIENT CONCERNS: In this case, we observed left common carotid artery occlusion based on both ultrasound and intraoperative exploration. For patients with syphilitic aortic aneurysm, the first choice is still sufficient antibiotic therapy. The surgical indications include symptom relief and prevention of aortic rupture or sudden death. DIAGNOSES: Aortic valve insufficiency, aortic aneurysm, and syphilis. INTERVENTIONS: Aortic valve replacement, aneurysmectomy and total arch replacement combined with frozen elephant trunk implantation via single upper hemisternotomy approach. OUTCOMES: The patient did not suffer reventilation and reoperation. No transient or permanent neurological dysfunction was observed in this patient. And no acute renal failure occurred. The patient was discharged on 43 days after the operation. LESSONS SUBSECTIONS: The upper hemisternotomy has the advantages of faster postoperative recovery, shorter ventilation time, shorter intensive care unit stay, less blood transfusion, and less incisional pain compared with the full sternotomy, which is one of the reasons why we chose this procedure for this patient.

Ascending aortic rupture incidentally revealed at the cath lab: surprising, rare, and life-threatening.

An 80-year-old woman who was an active smoker with neglected long-term hypertension, but no known previous aortic or connective tissue disorders, presented to the emergency department complaining of sudden chest pain associated with cardiogenic shock.

Left coronary sinus of valsalva aneurysm dissecting into interventricular septum: a case report.

BACKGROUND: Sinus of Valsalva aneurysm (SVA) is an extremely rare condition, and its rupture causes acute symptoms such as chest pain and dyspnea. Ruptured SVA is frequently associated with other congenital defects. CASE PRESENTATION: A 37-year-old male presented with SVA originating from the left coronary sinus that ruptured into the interventricular septum. SVA was diagnosed by echocardiography, cardiac computed tomography and magnetic resonance imaging, and confirmed during the operation. CONCLUSIONS: SVA is a rare cardiac abnormality which can lead to severe clinical symptoms upon rupture. Immediate surgery is necessary to repair the ruptured SVA.

Size thresholds for repair of abdominal aortic aneurysms warrant reconsideration.

BACKGROUND: The historical size threshold for abdominal aortic aneurysm (AAA) repair is widely accepted to be 5.5 cm for men and 5.0 cm for women. However, contemporary AAA rupture risks may be lower than historical benchmarks, which has implications for when AAAs should be repaired. Our objective was to use contemporary AAA rupture rates to inform optimal size thresholds for AAA repair. METHODS: We used a Markov chain analysis to estimate life expectancy for patients with AAA. The primary outcome was AAA-related mortality. We estimated survival using Social Security Administration life tables and published contemporary AAA rupture estimates. For those undergoing repair, we modified survival estimates using data from the Vascular Quality Initiative and Medicare on complications, late rupture, and open conversion. We used this model to estimate the AAA repair size threshold that minimizes AAA-related mortality for 60-year-old average-health men and women. We performed a sensitivity analysis of poor-health patients and 70- and 80-year-old base cases. RESULTS: The annual risk of all-cause mortality under surveillance for a 60-year-old woman presenting with a 5.0 cm AAA using repair thresholds of 5.5 cm, 6.0 cm, 6.5 cm, and 7.0 cm was 1.7%, 2.3%, 2.7%, and 2.8%, respectively. The corresponding risk for a man was 2.3%, 2.9%, 3.3%, and 3.4% for the same repair thresholds, respectively. For a 60-year-old average-health woman, an AAA repair size of 6.1 cm was the optimal threshold to minimize AAA-related mortality. Life expectancy varied by <2 months for repair at sizes from 5.7 cm to 7.1 cm. For a 60-year-old average-health man, an AAA repair size of 6.9 cm was the optimal threshold to minimize AAA-related mortality. Life expectancy varied by <2 months for repair at sizes from 6.0 cm to 7.4 cm. Women in poor health, at various age strata, had optimal AAA repair size thresholds that were >6.5 cm, whereas men in poor health, at all ages, had optimal repair size thresholds that were >8.0 cm. CONCLUSIONS: The optimal threshold for AAA repair is more nuanced than a discrete size. Specifically, there appears to be a range of AAA sizes for which repair is reasonable to minmized AAA-related mortality. Notably, they all are greater than current guideline recommendations. These findings would suggest that contemporary AAA size thresholds for repair should be reconsidered.

A Multidisciplinary Protocolized Approach for Ruptured Abdominal Aortic Aneurysm Management: A Retrospective Before-After Study.

OBJECTIVES: To investigate whether implementation of a multidisciplinary protocol for ruptured abdominal aortic aneurysm (rAAA) management reduces rates of adverse complications. DESIGN: A retrospective before-after study. SETTING: A tertiary-care academic hospital. PARTICIPANTS: Adult patients who underwent open or endovascular rAAA repair; data were stratified into before-protocol implementation (group 1: 2015-2018) and after-protocol implementation (group 2: 2019-2022) groups. INTERVENTION: The protocol details the workflow for vascular surgery, anesthesia, emergency department, and operating room staff for a rAAA case; training was accomplished through yearly workshops. MEASUREMENTS AND MAIN RESULTS: The primary outcome was in-hospital mortality. Secondary outcomes included all-cause morbidity and other major complications. Differences in postoperative complication rates between groups were assessed using Pearson's χ2 test. Of the 77 patients included undergoing rAAA repair, 41 (53.2%) patients were in group 1, and 36 (46.8%) patients were in group 2. Patients in group 2 had a significantly shorter median time to incision (1.0 v 0.7 hours, p = 0.022) and total procedure time (180.0 v 160.5 minutes, p = 0.039) for both endovascular and open repair. After protocol implementation, patients undergoing endovascular repair exhibited significantly lower rates of mortality (46.2% v 20.0%, p = 0.048), all-cause morbidity (65.4% v 44.0%, p = 0.050), and renal complications (15.4% v 0.0%, p = 0.036); patients undergoing open repair for a rAAA exhibited significantly lower rates of mortality (53.3% v 27.3%, p = 0.018) and bowel ischemia (26.7% v 0.0%, p = 0.035). CONCLUSIONS: Implementation of a multidisciplinary protocol for the management of a rAAA may reduce rates of adverse complications and improve the quality of care.

Evaluation of associations between outflow morphology and rupture risk of abdominal aortic aneurysms.

PURPOSE: This study aimed to evaluate the association between the outflow morphology and abdominal aortic aneurysm (AAA) rupture risk, to find risk factors for future prediction models. MATERIALS AND METHODS: We retrospectively analyzed 46 patients with ruptured AAAs and 46 patients with stable AAAs using a 1:1 match for sex, age, and maximum aneurysm diameter. The chi-square test, paired t-test, and Wilcoxon signed-rank test were used to compare variables. Logistic regression was performed to evaluate variables potentially associated with AAA rupture. Receiver operating characteristic curve analysis and the area under the curve (AUC) were used to assess the regression models. RESULTS: Ruptured AAAs had a shorter proximal aortic neck (median (interquartile range, IQR): 24.0 (9.4-34.2) mm vs. 33.3 (20.0-52.8) mm, p = 0.004), higher tortuosity (median(IQR): 1.35 (1.23-1.49) vs. 1.29 (1.23-1.39), p = 0.036), and smaller minimum luminal area of the right common iliac artery (CIA) (median (IQR): 86.7 (69.9-126.4) mm2 vs. 118.9 (86.3-164.1)mm2, p = 0.001) and left CIA (median(IQR): 92.2 (67.3,125.1) mm2 vs. 110.7 (80.12, 161.1) mm2, p = 0.010) than stable AAA did. Multiple regression analysis demonstrated significant associations of the minimum luminal area of the bilateral CIAs (odds ratio [OR] = 0.996, 95 % confidence interval [CI] 0.991-0.999, p = 0.037), neck length (OR = 0.969, 95 % CI 0.941-0.993, p = 0.017), and aneurysm tortuosity (OR = 1.031, 95 % CI 1.003-1.063, p = 0.038) with ruptured AAAs. The AUC of this regression model was 0.762 (95 % CI 0.664-0.860, p < 0.001). CONCLUSIONS: The smaller minimum luminal area of the CIA is associated with an increased risk of rupture. This study highlights the potential of utilizing outflow parameters as novel and additional tools in risk assessment. It also provides a compelling rationale to further intensify research in this area.

Animal Models, Pathogenesis, and Potential Treatment of Thoracic Aortic Aneurysm.

Thoracic aortic aneurysm (TAA) has a prevalence of 0.16-0.34% and an incidence of 7.6 per 100,000 person-years, accounting for 1-2% of all deaths in Western countries. Currently, no effective pharmacological therapies have been identified to slow TAA development and prevent TAA rupture. Large TAAs are treated with open surgical repair and less invasive thoracic endovascular aortic repair, both of which have high perioperative mortality risk. Therefore, there is an urgent medical need to identify the cellular and molecular mechanisms underlying TAA development and rupture to develop new therapies. In this review, we summarize animal TAA models including recent developments in porcine and zebrafish models: porcine models can assess new therapeutic devices or intervention strategies in a large mammal and zebrafish models can employ large-scale small-molecule suppressor screening in microwells. The second part of the review covers current views of TAA pathogenesis, derived from recent studies using these animal models, with a focus on the roles of the transforming growth factor-beta (TGFß) pathway and the vascular smooth muscle cell (VSMC)-elastin-contractile unit. The last part discusses TAA treatment options as they emerge from recent preclinical studies.

Ketosis prevents abdominal aortic aneurysm rupture through C-C chemokine receptor type 2 downregulation and enhanced extracellular matrix balance.

Abdominal aortic aneurysms (AAAs) are prevalent with aging, and AAA rupture is associated with increased mortality. There is currently no effective medical therapy to prevent AAA rupture. The monocyte chemoattractant protein (MCP-1)/C-C chemokine receptor type 2 (CCR2) axis critically regulates AAA inflammation, matrix-metalloproteinase (MMP) production, and extracellular matrix (ECM) stability. We therefore hypothesized that a diet intervention that can modulate CCR2 axis may therapeutically impact AAA risk of rupture. Since ketone bodies (KBs) can trigger repair mechanisms in response to inflammation, we evaluated whether systemic ketosis in vivo could reduce CCR2 and AAA progression. Male Sprague-Dawley rats underwent surgical AAA formation using porcine pancreatic elastase and received daily ß-aminopropionitrile to promote AAA rupture. Rats with AAAs received either a standard diet, ketogenic diet (KD), or exogenous KBs (EKB). Rats receiving KD and EKB reached a state of ketosis and had significant reduction in AAA expansion and incidence of rupture. Ketosis also led to significantly reduced aortic CCR2 content, improved MMP balance, and reduced ECM degradation. Consistent with these findings, we also observed that Ccr2-/- mice have significantly reduced AAA expansion and rupture. In summary, this study demonstrates that CCR2 is essential for AAA expansion, and that its modulation with ketosis can reduce AAA pathology. This provides an impetus for future clinical studies that will evaluate the impact of ketosis on human AAA disease.