Construction of ferroptosis-related prediction model for pathogenesis, diagnosis and treatment of ruptured abdominal aortic aneurysm.

Abdominal aortic aneurysm (AAA) is a dangerous cardiovascular disease, which often brings great psychological burden and economic pressure to patients. If AAA rupture occurs, it is a serious threat to patients' lives. Therefore, it is of clinical value to actively explore the pathogenesis of ruptured AAA and prevent its occurrence. Ferroptosis is a new type of cell death dependent on lipid peroxidation, which plays an important role in many cardiovascular diseases. In this study, we used online data and analysis of ferroptosis-related genes to uncover the formation of ruptured AAA and potential therapeutic targets. We obtained ferroptosis-related differentially expressed genes (Fe-DEGs) from GSE98278 dataset and 259 known ferroptosis-related genes from FerrDb website. Enrichment analysis of differentially expressed genes (DEGs) was performed by gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG). Receiver Operating characteristic (ROC) curve was employed to evaluate the diagnostic abilities of Fe-DEGs. Transcription factors and miRNAs of Fe-DEGs were identified through PASTAA and miRDB, miRWalk, TargetScan respectively. Single-sample gene set enrichment analysis (ssGSEA) was used to observe immune infiltration between the stable group and the rupture group. DGIdb database was performed to find potential targeted drugs of DEGs. GO and KEGG enrichment analysis found that DEGs mainly enriched in "cellular divalent inorganic cation homeostasis," "cellular zinc ion homeostasis," "divalent inorganic cation homeostasis," "Mineral absorption," "Cytokine - cytokine receptor interaction," "Coronavirus disease - COVID-19." Two up-regulated Fe-DEGs MT1G and DDIT4 were found to further analysis. Both single and combined applications of MT1G and DDIT4 showed good diagnostic efficacy (AUC = 0.8254, 0.8548, 0.8577, respectively). Transcription factors STAT1 and PU1 of MT1G and ARNT and MAX of DDIT4 were identified. Meanwhile, has_miR-548p-MT1G pairs, has_miR-53-3p/has_miR-181b-5p/ has_miR-664a-3p-DDIT4 pairs were found. B cells, NK cells, Th2 cells were high expression in the rupture group compared with the stable group, while DCs, Th1 cells were low expression in the rupture group. Targeted drugs against immunity, GEMCITABINE and INDOMETHACIN were discovered. We preliminarily explored the clinical significance of Fe-DEGs MT1G and DDIT4 in the diagnosis of ruptured AAA, and proposed possible upstream regulatory transcription factors and miRNAs. In addition, we also analyzed the immune infiltration of stable and rupture groups, and found possible targeted drugs for immunotherapy.

[Clinical data analysis of 117 patients with ruptured abdominal aortic aneurysm].

Objective: To examine the perioperative clinical features and prognosis of patients with ruptured abdominal aortic aneurysms (rAAA) who received surgical repair. Methods: The clinical data of rAAA patients who underwent surgical repair and were admitted to the Surgical Intensive Care Unit of Beijing Anzhen Hospital, Capital Medical University from August 2005 to November 2020 were retrospectively analyzed, including the general clinical features, surgical mode, intraoperative conditions, postoperative complications, and fatality rate. Results: There were 117 patients with rAAA, with a median age of 68 (62,77) years, including 93 men (79.5%) and 24 women (20.5%). The main clinical manifestation was abdominal pain (n=115, 98.3%). Among them, 65 (55.6%) patients underwent endovascular aneurysm repair (EVAR), while 52 (44.4%) underwent open surgical repair (OSR). The common postoperative complications include acute gastrointestinal dysfunction (n=116, 99.1%), shock (n=89, 76.1%), acute respiratory distress syndrome (n=85, 72.6%), pancreatic injury (n=56, 47.9%), coagulation dysfunction (n=55, 47.0%), disseminated intravascular coagulation (n=46, 39.3%), acute kidney injury (n=39, 33.3%), infection/sepsis (n=28, 23.9%), gastrointestinal bleeding (n=17, 14.5%), and abdominal compartment syndrome (n=12, 10.3%). The overall postoperative in-hospital fatality rate was 10.3% (12/117). Preoperative use of vasopressors and inotropes, retroperitoneal hematoma, and postoperative abdominal compartment syndrome, gastrointestinal hemorrhage, acute kidney injury, and diffuse intravascular coagulation significantly increased the fatality rate [5/11, 6/24, 5/16, 6/12, 6/17, 23.1%(9/39), 19.6%(9/46), respectively]. Conclusion: The postoperative mortality of rAAA patients is still high in the era of EVAR, especially in patients with preoperative existence of shock and retroperitoneal hematoma, and with postoperative abdominal compartment syndrome, coagulation dysfunction, and acute kidney injury. It is necessary to strengthen perioperative monitoring and management of these patients to reduce the fatality rate.

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.

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.

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.

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.

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.

[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.

Spontaneous rupture of the right aortic sinus resulting in a sterile aorto-atrial fistula in a pet rabbit (Oryctolagus cuniculus).

Aortocardiac fistula is a broad term used to describe defects between the aorta and other cardiac chambers that can occur in humans and animals. A 1.5-year-old, 1.7 kg, male castrated Holland lop rabbit (Oryctolagus cuniculus) was presented for a two-week history of a heart murmur with corresponding cardiomegaly on radiographs. Physical examination confirmed a grade-V/VI continuous heart murmur on the right sternal border with a regular rhythm and a gallop sound. Echocardiography revealed an aortic-to-right-atrial fistula causing severe left-sided volume overload. Based on the echocardiographic findings, rupture of the right aortic sinus was suspected. Due to the poor prognosis, euthanasia was elected. On necropsy, a fistula was found connecting the right aortic sinus with the right atrium, without evidence of an inflammatory response nor evidence of an infectious etiology. The sudden onset of a heart murmur supported acquired fistulation from a ruptured aortic sinus (also known as the sinus of Valsalva), though a congenital malformation could not be completely excluded.

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.

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.

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.

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.

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.

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.