Rupture rates of untreated large abdominal aortic aneurysms in patients unfit for elective repair

Three-dimensional characterization of sex differences in abdominal aortic aneurysm progression via vascular deformation mapping

Although abdominal aortic aneurysms (AAA) are more common in men, women are at greater risk for AAA growth/rupture. Vascular deformation mapping (VDM) utilizes deformable image registration to qualify and quantify 3D-AAA growth using computed tomography angiograms (CTA). In this study we leveraged VDM to investigate sex differences in AAA growth patterns. Patients with infra-renal AAA and ≥ 2 CTA were identified. Males and females were matched for age, hypertension, and smoking history. Patient characteristics, maximum diameter (Dmax), and AAA volume were obtained. CTA images were segmented, and VDM was conducted to quantify 3D AAA growth rate per year (GR, cm/year). Statistical shape modeling was utilized to compute mean aneurysm shapes and 3D GR. Average GR was evaluated at specific regions of the aortic surface for males and females. Seventeen males and 17 females were matched. At the individual level, there were no sex differences in changes in Dmax or AAA volume. However, females had larger GR across the anterior and right lateral AAA (1.33 vs 0.89 and 1.56 vs 0.74 cm/year, respectively), despite no difference in posterior or left lateral AAA GR. Despite comparable changes in Dmax, AAA volume, and GR magnitude, women demonstrated a more eccentric, anterior-predominant, AAA growth pattern.

Exploring the Acceptable Delay for Elective Treatment of Patients With an Abdominal Aortic Aneurysm: A Reflection During a Pandemic and an Exploratory Analysis

INTRODUCTION

This study sought to determine the rupture risk of asymptomatic abdominal aortic aneurysms (AAAs) undergoing interventions as a function of time to establish a maximal acceptable surgical delay.

METHODS

A literature review was performed from inception to August 30, 2021, to assess the risk of rupture of aneurysms over time. The analysis was limited to men with asymptomatic AAAs. The data on AAA rupture risk according to diameter and follow-up time were extracted. The acceptable mortality risk for AAA patients as a function of surgical delay was further evaluated. This acceptable mortality risk was based on the acceptable risk of cardiovascular death associated with the accepted delays of coronary revascularization in coronary artery disease populations. Data on estimated surgical delays and risks were extracted using a free web-based software (WebPlotDigitizer) and plotted using Microsoft Excel.

RESULTS

Our study identified minimal evidence as it pertains to AAA rupture risk as a function of surgical delay. The data on rupture risk of AAAs according to diameter and time were extracted from a single review and a single meta-analysis (Figure 1). The acceptable delays of semiurgent and nonurgent invasive treatment for coronary artery disease found in literature are 6 and 12 wks respectively. These acceptable delays are associated with an estimated acceptable cardiovascular mortality risk threshold of 0.47% at 6 and 12 wks. Using this threshold of estimated maximum acceptable risk and the data on the natural history of AAAs found in our review, we found that the acceptable surgical delays for AAAs would be estimated at 13-27 ds for AAAs ≥ 7 cm, 20-42 ds for 6-6.9 cm, and 32-49 ds for 5.5-5.9 cm (Figure 1).

CONCLUSIONS

This study identified estimated surgical delays for patients with AAAs based on the acceptable maximum risk. These estimations may be used cautiously to triage patients with asymptomatic AAAs, particularly in the setting of triaging patients during local and global crises.

The Safety and Outcomes of Elective Endovascular Aneurysm Repair in the Elderly: A Systemic Review and Meta-Analysis

PURPOSE

Prevalence of abdominal aortic aneurysms (AAAs) increases with age. Previous trials confirm that elective endovascular aneurysm repair (EVAR) is an effective intervention for AAA. However, few elderly patients were recruited into randomized trials, whereas in contemporary clinical practice, elective repair is commonly performed on octogenarians. We evaluated the safety and outcome of elective EVAR in elderly patients to inform clinical practice and vascular service provision.

METHODS

A systematic review and meta-analysis of studies reporting risk of complications and death in patients undergoing elective EVAR was performed (PROSPERO CRD: 42022308423). Observational studies and interventional arms of randomized trials were included if the outcome rates or raw data were provided. Primary outcome was 30-day mortality. Secondary outcomes were longer-term mortality, 30-day major adverse events, and aneurysm-related mortality. Primary and secondary outcomes were compared between octogenarians and non-octogenarians. Exclusion criteria were emergency procedures, non-infrarenal aneurysms, and lack of octogenarian data.

RESULTS

A total of 41 studies were eligible from 10 099 citations, including 10 national and 5 international registries, 26 retrospective studies, and our own prospective cohort. The analysis included 208 997 non-octogenarians (mean age=70.19 [SD=0.62]) and 106 188 octogenarians (mean age=83.75 [SD=0.35]). The 30-day mortality post-elective EVAR was higher in octogenarians (1.08% in non-octogenarians, 2.31% in octogenarians, odds ratio [OR]=2.27 [2.08-2.47], p<0.0001). Linear regression demonstrated a 0.83% increase in 30-day mortality for every 10-year age increase above 60 years old. Mortality for octogenarians increased significantly during follow-up: 11.35% (OR=1.87 [1.65-2.13], p<0.001), 22.80% (OR=1.89 [1.52-2.35], p<0.001), 32.00% (OR=1.98 [1.66-2.37], p<0.001), 47.53%, and 51.08% (OR=2.40 [1.90-3.03], p<0.001) at 1-through-5-year follow-up, respectively. The 30-day major adverse events after elective EVAR were higher in octogenarians (OR=1.75-2.83, p<0.001).

CONCLUSIONS

Octogenarians experience higher but acceptable peri-operative morbidity and mortality compared with younger patients. However, 3-year to 5-year survival is very low among octogenarians. Our findings challenge the notion of routine intervention in elderly patients and support very careful selection for elective EVAR. Many octogenarians with peri-threshold (<6 cm) AAAs may derive no benefit from EVAR due to limited 3-year to 5-year overall survival and low risk of aneurysm rupture with conservative management. An adjusted threshold for intervention in octogenarians may be warranted.

CLINICAL IMPACT

Octogenarians with infra-renal AAA are increasingly managed with elective EVAR. Previous studies have demonstrated that EVAR is safer than open repair for octogenarians, with lower peri-operative mortality and major adverse events. However, randomised trials, on which much of contemporary evidence is based, recruited a relatively younger population of participants. This systematic review and meta-analysis provides a contemporary synthesis of the literature comparing outcomes in octogenarians to younger patients. The results of this analysis, together with low rupture rates amongst octogenarians in existing literature, question the benefit of routine elective intervention for peri-threshold aneurysms and an adjusted threshold for intervention in octogenarians may be warranted.

Tension-based abdominal aortic aneurysm rupture risk assessment improves its accuracy and reduces the time of analysis

The biomechanical rupture risk assessment (BRRA) of abdominal aortic aneurysms (AAA) has higher sensitivity than maximal diameter criterion (DSEX) but its estimation is time-consuming and relies on an uncertain estimation of wall thickness. The aim of this study is to test tension-based criterion in the BRRA of AAA which removes the necessity of wall thickness measurement and should be faster. For that, we retrospectively analyzed 99 patients with intact AAA (25 females). Nineteen of them experienced a rupture later. BRRA was performed with wall tension PRRIT as a primary criterion. The ability of criterion to separate intact and ruptured AAAs at 1,3,6,9 and 12 months was estimated. Next, the receiver operating characteristics and the percentage of true negative cases for a different time to an outcome were estimated. Finally, the computational time was recorded. The results were compared to stress-based criterion PRRI and DSEX which served as a reference. All three criterions were able to discriminate between intact and ruptured AAAs up to 9 months (p < 0.05) while none of them could do for a 12 month prediction. PRRIT exhibited a significantly higher percentage of true negatives for 12 and 9 month predictions (45 % and 20 % respectively) and similar to other criteria for other prediction times. The mean computational time for estimating PRRIT was 19 h per patient compared to 67 h for PRRI. The tension- based BRRA of AAA leads to better outcomes for a 9 and 12 month prediction while the computational time drops by more than 70 % compared to PRRI.

Sealing Zone Failure Decreases the Long Term Durability of Endovascular Aneurysm Repair

OBJECTIVE

Endovascular aneurysm repair (EVAR) has a higher long term aneurysm related mortality rate compared with open surgery, mainly due to aneurysm rupture. Loss of stent graft to vessel apposition at the EVAR sealing zones is a potential cause of post-EVAR rupture. This study aimed to investigate sealing zone failure and its relationship with post-EVAR rupture.

METHODS

This was a retrospective structured review of pre- and post-operative computed tomography (CT) scans of 399 consecutive patients treated with standard bifurcated EVAR. The primary outcome was total loss of seal at last post-operative CT. Secondary outcomes were partial loss of seal, standard follow up detection, post-EVAR rupture, aneurysm sac development, and endoleaks.

RESULTS

During a median follow up of 5.3 years, total and partial loss of seal occurred in 85 (21.3%) and 78 (19.5%) patients, respectively. Initial mean sealing zone lengths were within current recommendations but decreased over time, mainly due to vessel dilatation. Mean proximal sealing length at the one month CT was 15.5 ± 10.5 mm (95% confidence interval [CI] 12.6 - 18.5 mm) in the group with total loss of seal, 14.3 ± 6.9 mm (95% CI 12.2 - 16.4 mm) with partial loss of seal, and 23.2 ± 7.4 mm (95% CI 22.3 - 24.0 mm) with preserved seal through follow up (p < .001). Mean iliac sealing lengths were 22.4 ± 12.1 mm (95% CI 18.9 - 25.8 mm) if total loss and 21.8 ± 10.0 mm (95% CI 19.6 - 24.0 mm) if partial loss of seal vs. 34.7 ± 12.4 mm (95% CI 33.8 - 35.7 mm) if preserved seal. Larger vessel diameters were associated with loss of seal in both the proximal and distal sealing zones. During the study period, 13 post-EVAR ruptures occurred, all preceded by CT findings of total (n = 7) or partial (n = 6) loss of seal. Aneurysm sac expansion was seen in 40% of patients with total loss of seal, 18% with partial loss of seal, and 6.6% with preserved seal.

CONCLUSION

Loss of seal after EVAR is frequent and associated with post-EVAR rupture. Increased recommended sealing zones lengths and focus on sealing zones in surveillance may reduce post-EVAR ruptures and aneurysm related death.

Preoperative clinical characteristics and 12-month outcomes following operative or non-operative management of asymptomatic aortic aneurysms

DESIGN

An observational cohort study conducted at a tertiary referral center for aortic surgery to describe the medical and surgical characteristics of patients assessed for abdominal aortic aneurysm repair and examine associations with 12-month outcome.

METHODS

Patients with aortic aneurysms referred for discussion at the aortic multidisciplinary meeting (MDM). Data were collected via a prospectively maintained clinical database and included aneurysm characteristics, patient demographics, co-morbidities, geriatric syndromes, including frailty, management decision and 12-month mortality, both aneurysm-related and all-cause including cause of death. The operative and non-operative groups were compared statistically.

RESULTS

621 patients referred to aortic MDM; 292 patients listed for operative management, 141 patients continued on surveillance, 138 patients for non-operative management. There was a higher 12-month mortality rate in the non-operative group compared to the operative group (41% vs 7%, P = <0.001). In the non-operative group, 16 patients (29%) died of aneurysm rupture within 12 months, with 39 patients (71%) dying from other medical causes. Non-operatively managed patients were older, more likely to have cardiac and respiratory disease and more likely to be living with frailty, cognitive impairment and functional limitation, compared to the operative group.

CONCLUSION

This study shows that preoperative geriatric syndromes and increased comorbidity lead to shared decision to non-operatively manage asymptomatic aortic aneurysms. Twelve-month mortality is higher in the non-operative group with the majority of deaths occurring due to cause other than aneurysm rupture. These findings support the need for preoperative comprehensive geriatric assessment followed by multispecialty discussion and shared decision making.

Ruptured AAA: bridging the gap between international guidelines and local clinical realities

BACKGROUND

Treatment of asymptomatic Abdominal Aortic Aneurysms (AAA) presents a clinical challenge, requiring a delicate balance between rupture risk, patient comorbidities, and intervention-related complications. International guidelines recommend intervention for specific AAA size thresholds, but these are based on historical trials with limited female representation. We aimed to analyse disease characteristics, AAA size at rupture, and intervention outcomes in patients with ruptured AAA from 2009 to 2023 to investigate the gap between guidelines and local realities.

METHODS

This single-centre retrospective cohort study analysed electronic health records of patients treated for a ruptured AAA, excluding those who were managed palliatively. The study assessed patients' demographics, risk factors, comorbidities, clinical presentation, radiological characteristics, and outcomes.

RESULTS

Of 164 patients (41 females, 123 males, median age 73.5), 93.3% presented with abdominal or back pain. The median AAA size at rupture was 8.0 cm in males and 7.6 cm in females. No significant correlations were found between demographic characteristics, risk factors, AAA size, repair modality, and outcomes. Trends show a decline in AAA prevalence and rupture rates, aligning with global health initiatives. Post-intervention survival rates at 30 days were 70.7% (67.5% in males and 80.0% in females), and at 2 years were 65.85% (61.7% in males and 70.0% in females).

CONCLUSION

Evolving AAA trends and improved post-intervention survival rates warrant a critical reassessment of existing intervention recommendations. Adjusting intervention thresholds to larger sizes may be justified to optimise the risk-benefit ratio.

A prospective longitudinal study of risk factors for abdominal aortic aneurysm

The aim of this study was to identify risk factors for abdominal aortic aneurysm (AAA) from the largest Welsh screening cohort to date. Patients were recruited from 1993 (to 2015) as part of the South East Wales AAA screening programme through general practitioners. Demographic data and risk factors were collected by means of a self-report questionnaire. Statistical tests were performed to determine whether associations could be observed between AAA and potential risk factors. Odds ratios (OR) were also calculated for each of the risk factors identified. A total of 6879 patients were included in the study. Two hundred and seventy-five patients (4.0%) presented with AAA, of which 16% were female and 84% were male. Patients with AAA were older than the (no AAA) control group (p < 0.0001). The following risk factors were identified for AAA: family history of AAA (p < 0.0001); history of vascular surgery (p < 0.0001), cerebrovascular accident (p < 0.0001), coronary heart disease (p < 0.0001), diabetes (p < 0.0001), medication (p = 0.0018), claudication (p < 0.0001), smoking history (p = 0.0001) and chronic obstructive pulmonary disorder (p = 0.0007). AAA is associated with classical vascular risk factors, in addition to other less-well-documented risk factors including previous vascular surgery. These findings have practical implications with the potential to improve future clinical screening of patients in order to reduce AAA mortality.

Friendly Neck Anatomy Does Not Prevent Neck-Related Adverse Events After EVAR

BACKGROUND

Life-long follow-up after endovascular aneurysm repair (EVAR) is costly and burdensome to the patient. Follow-up should be stratified based on the risk of EVAR failure. Aneurysm neck is thought to be the single most important risk factor. This study investigated neck anatomy as a predictor of neck-related adverse events after EVAR.

METHODS

This retrospective single-center study included consecutive patients undergoing elective EVAR for infrarenal abdominal aortic aneurysms between 2011 and 2016 (n = 222) who were followed with yearly imaging until December 2020. Hostile neck was defined as neck length ≤15 mm, width ≥28 mm, angulation ≥60°, calcification, or thrombus ≥50% of circumference or conical neck based on preoperative computed tomography angiography. Neck-related adverse event was defined as aneurysm rupture, any neck-related reintervention or type 1a endoleak during follow-up.

RESULTS

Ninety (41%) patients had hostile neck and 132 (59%) had friendly neck. There were no differences in 30-day mortality (1% vs. 1%, P = 0.78), major adverse events (20% vs. 16%, P = 0.43) or reinterventions during the hospital stay (8% vs. 4%, P = 0.20) between patients with hostile and friendly neck. Estimated survival at 1 year was 89 ± 3% for hostile neck and 95 ± 2% for friendly neck patients (P < 0.01). Five-year survival estimates were 51 ± 6% and 66 ± 4%, respectively. Aneurysm-related mortality was higher after 6 years in patients with hostile neck (P < 0.01). Twenty-four patients (11%) suffered neck-related adverse events with mean time-to-event of 3.3 ± 2.8 years; there were no differences between the groups stratified by neck anatomy. Incidentally, preoperative aneurysm diameter was found to be an independent risk factor for neck-related adverse events and aneurysm-related mortality; 53 patients (24%) had aneurysm diameter ≥70 mm, which was associated with nearly 4-fold risk of neck-related complications during the follow-up.

CONCLUSIONS

Friendly neck anatomy may not protect from neck-related adverse events after EVAR in the long-term. Especially patients with large aneurysms should be followed closely.

A systematic review and case presentation: Giant abdominal aortic aneurysm

OBJECTIVE

An abdominal aortic aneurysm is considered giant when its transverse diameter is greater than 10-13 cm in diameter. A giant abdominal aortic aneurysm is rare but with a significant risk of rupture if it is not diagnosed or left untreated.

METHOD

The authors have performed a systematic review of the evidence that has looked into the clinical presentations, and management methods employed and have presented a 14 cm giant abdominal aortic aneurysm patient.

RESULTS

The systematic review has been based on level-IV evidence due to the rarity of the condition. The final analysis included 61 relevant reported cases. The mean age was 72.4 years, the male to female ratio was 52: 8, and the average size of a giant abdominal aortic aneurysm was 14.7 cm. These were mostly infra renal (72.58%). Rupture of these aneurysms was found in 23 (37.1%) patients, and was treated by laparotomy in 51 (82.25%) cases. There were 11 (17.74%) mortalities.

CONCLUSION

The size of an abdominal aortic aneurysm is known to be the biggest factor in the rupture of an aneurysm. The reason abdominal aortic aneurysms can reach such size without rupturing is unclear but needs further exploring. Early diagnosis with effective screening programmes is essential to diagnose in a timely manner to avoid life-threatening consequences.

Identification and Evaluation of Blood-Based Biomarkers for Abdominal Aortic Aneurysm

INTRODUCTION

Blood-based biomarkers for abdominal aortic aneurysm (AAA) have been studied individually; however, we considered a panel of proteins to investigate AAA prognosis and its potential to improve predictive accuracy.

MATERIALS AND METHODS

Using a prospectively recruited cohort of patients with/without AAA (n = 452), we conducted a prognostic study to develop a model that accurately predicts AAA outcomes using clinical features and circulating biomarker levels. Serum concentrations of 9 biomarkers were measured at baseline, and the cohort was followed for 2 years. The primary outcome was major adverse aortic event (MAAE; composite of rapid AAA expansion [>0.5 cm/6 months or >1 cm/12 months], AAA intervention, or AAA rupture). Using 10-fold cross-validation, we trained a random forest model to predict 2 year MAAE using (1) clinical characteristics, (2) biomarkers, and (3) clinical characteristics and biomarkers.

RESULTS

Two-year MAAE occurred in 114 (25%) patients. Two proteins were significantly elevated in patients with AAA compared with those without AAA (angiopoietin-2 and aggrecan), composing the protein panel. For predicting 2 year MAAE, our random forest model achieved area under the receiver operating characteristic curve (AUROC) 0.74 using clinical features alone, and the addition of the 2-protein panel improved performance to AUROC 0.86.

CONCLUSIONS

Using a combination of clinical/biomarker data, we developed a model that accurately predicts 2 year MAAE.

A dedicated risk prediction model of 1-year mortality following endovascular aortic aneurysm repair involving the renal-mesenteric arteries

OBJECTIVE

Treatment goals of prophylactic endovascular aortic repair of complex aneurysms involving the renal-mesenteric arteries (complex endovascular aortic repair [cEVAR]) include achieving both technical success and long-term survival benefit. Mortality within the first year after cEVAR likely indicates treatment failure owing to associated costs and procedural complexity. Notably, no validated clinical decision aid tools exist that reliably predict mortality after cEVAR. The purpose of this study was to derive and validate a preoperative prediction model of 1-year mortality after elective cEVAR.

METHODS

All elective cEVARs including fenestrated, branched, and/or chimney procedures for aortic disease extent confined proximally to Ishimaru landing zones 6 to 9 in the Society for Vascular Surgery Vascular Quality Initiative were identified (January 2012 to August 2023). Patients (n = 4053) were randomly divided into training (n = 3039) and validation (n = 1014) datasets. A logistic regression model for 1-year mortality was created and internally validated by bootstrapping the AUC and calibration intercept and slope, and by using the model to predict 1-year mortality in the validation dataset. Independent predictors were assigned an integer score, based on model beta-coefficients, to generate a simplified scoring system to categorize patient risk.

RESULTS

The overall crude 1-year mortality rate after elective cEVAR was 11.3% (n = 456/4053). Independent preoperative predictors of 1-year mortality included chronic obstructive pulmonary disease, chronic renal insufficiency (creatinine >1.8 mg/dL or dialysis dependence), hemoglobin <12 g/dL, decreasing body mass index, congestive heart failure, increasing age, American Society of Anesthesiologists class ≥IV, current tobacco use, history of peripheral vascular intervention, and increasing extent of aortic disease. The 1-year mortality rate varied from 4% among the 23% of patients classified as low risk to 23% for the 24% classified as high risk. Performance of the model in validation was comparable with performance in the training data. The internally validated scoring system classified patients roughly into quartiles of risk (low, low/medium, medium/high and high), with 52% of patients categorized as medium/high to high risk, which had corresponding 1-year mortality rates of 11% and 23%, respectively. Aneurysm diameter was below Society for Vascular Surgery recommended treatment thresholds (<5.0 cm in females, <5.5 cm in males) in 17% of patients (n = 679/3961), 41% of whom were categorized as medium/high or high risk. This subgroup had significantly increased in-hospital complication rates (18% vs 12%; P = .02) and 1-year mortality (13% vs 5%; P < .0001) compared with patients in the low- or low/medium-risk groups with guideline-compliant aneurysm diameters (≥5.0 cm in females, ≥5.5 cm in males).

CONCLUSIONS

This validated preoperative prediction model for 1-year mortality after cEVAR incorporates physiological, functional, and anatomical variables. This novel and simplified scoring system can effectively discriminate mortality risk and, when applied prospectively, may facilitate improved preoperative decision-making, complex aneurysm care delivery, and resource allocation.

Doxycycline induces mitochondrial dysfunction in aortic smooth muscle cells

The antibiotic doxycycline is known to inhibit inflammation and was therefore considered as a therapeutic to prevent abdominal aortic aneurysm (AAA) growth. Yet mitochondrial dysfunction is a key-characteristic of clinical AAA disease. We hypothesize that doxycycline impairs mitochondrial function in the aorta and aortic smooth muscle cells (SMCs). Doxycycline induced mitonuclear imbalance, reduced proliferation and diminished expression of typical contractile smooth muscle cell (SMC) proteins. To understand the underlying mechanism, we studied krüppel-like factor 4 (KLF4). The expression of this transcription factor was enhanced in SMCs after doxycycline treatment. Knockdown of KLF4, however, did not affect the doxycycline-induced SMC phenotypic changes. Then we used the bioenergetics drug elamipretide (SS-31). Doxycycline-induced loss of SMC contractility markers was not rescued, but mitochondrial genes and mitochondrial connectivity improved upon elamipretide. Thus while doxycycline is anti-inflammatory, it also induces mitochondrial dysfunction in aortic SMCs and causes SMC phenotypic switching, potentially contributing to aortic aneurysm pathology. The drug elamipretide helps mitigate the harmful effects of doxycycline on mitochondrial function in aortic SMC, and may be of interest for treatment of aneurysm diseases with pre-existing mitochondrial dysfunction.

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.

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.

Outcomes of octogenarians receiving aortic repair

OBJECTIVE

Abdominal aortic aneurysm (AAA) repair is recommended for aneurysms greater than 5.5 cm in men and 5 cm in women. Because AAA is more common among the elderly, we sought to evaluate contemporary practices of elective AAA repair and 2-year postoperative outcomes in octogenarians.

METHODS

We identified octogenarians undergoing elective AAA repair in the Vascular Quality Initiative from 2012 to 2019. We included patients undergoing endovascular (EVAR) and open (OAR) aortic repair. Demographics and comorbid conditions were compared between patient groups. Frailty was calculated using previously published methods. Patients with frailty scores above the 75th percentile of the operative cohort were considered high frailty. The primary outcome was 1- and 2-year mortality. Secondary outcomes included postoperative complications. Standard statistical methods were utilized. Cox proportional hazard models were used to identify factors that affect mortality.

RESULTS

The frequency of AAA repair in octogenarians has remained stable. Of all aortic operations, 21.4% were performed on octogenarians; 9735 (23.3% of 41,712) EVAR and 755 (10.3% of 7325) OARs. Among octogenarian patients, 42.0% of EVARs were under size thresholds: 48.3% males ≤5.5 cm diameter and 21.5% females ≤5.0 cm diameter compared with 18.8% OARs: 23.4% males and 10.7% females. Additionally, 25.6% had high frailty scores. Among octogenarians, 1- and 2-year mortality was 9.3% ± 0.3% and 14.8% ± 0.4% for EVAR and 15.2% ± 1.3% and 18.9% ± 1.5% for OAR patients, respectively (P < .01). In-hospital mortality rate was higher after OAR (0.87% EVAR vs 7.55% OAR; P < .01) and differed with frailty (EVAR, low frailty 0.2% vs high frailty 1.7%; OAR, low frailty 2.3% vs high frailty 15.6%). For EVAR, patient factors associated with mortality included heart failure (hazard ratio [HR], 1.15; 95% confidence interval [CI], 1.06-1.25; P = .001) and dialysis (HR, 1.71; 95% CI, 1.13-2.59; P = .012). For OAR, coronary artery disease (HR, 1.55; 95% CI, 0.98-2.44; P = .062) was associated with mortality. Statin use was protective of mortality for all patients (EVAR: HR, 0.68; 95% CI, 0.60-0.78; P < .01): OAR: HR, 0.58; 95% CI, 0.37-0.92; P = .020). Among octogenarians, high frailty was independently associated with 2-year mortality (EVAR: HR, 3.36; 95% CI, 2.62-4.31; P < .01 and OAR: HR, 2.35; 95% CI, 1.09-5.10; P = .030).

CONCLUSIONS

Nationally, a large portion of elective AAA repair in octogenarians is performed below recommended size thresholds, one-quarter of whom are frail with poor long-term 2-year mortality rates. High 2-year mortality following AAA repair in this age group exceeds the published risk of rupture for 5- to 5.5-cm AAA, suggesting that increase in the size threshold of elective repair among octogenarians should be explored.

Early Relative Growth Rate of Abdominal Aortic Aneurysms and Future Risk of Rupture or Repair

OBJECTIVE

This study aimed to test whether the relative growth rate of subthreshold abdominal aortic aneurysms (AAAs) in the first 24 months of surveillance predicts the risk of future rupture or repair.

METHODS

This was a single centre retrospective observational analysis of all small (< 45 mm diameter) and medium (45 - 54 mm in men, 45 - 50 mm in women) AAAs entered into ultrasound surveillance between January 2002 and December 2019, which received ≥ 24 months of surveillance. Relative growth rates were calculated from measurements taken in the first 24 months of surveillance. The Kaplan-Meier method was used to estimate intervention and rupture free proportions five years following diagnosis for AAAs growing by < 5% and by ≥ 5% in the first 24 months of surveillance. Multivariable Cox regression analysis was used to further analyse this relationship by adjusting for factors found to be significantly associated with outcome in univariable analysis.

RESULTS

A total of 556 patients with AAAs (409 men, 147 women) were followed for ≥ 24 months. This included 431 small AAAs. Of these, 109 (25.3%) grew by < 5% in the first 24 months of surveillance and had a cumulative event free proportion of 0.98 ± 0.05 at five years compared with 0.78 ± 0.05 for the ≥ 5% growth group (p < .001). Of 125 medium AAAs, 26 (20.8%) grew by < 5% in the first 24 months of surveillance and had a cumulative event free proportion of 0.73 ± 0.11 at five years compared with 0.29 ± 0.13 for the ≥ 5% growth group (p = .024). Baseline diameter and early relative growth rate were strongly and independently predictive of future intervention or rupture with hazard ratios of 9.16 (95% CI 5.98 - 14.03, p < .001) and 4.46 (95% CI 2.45 - 8.14, p < .001), respectively.

CONCLUSION

The results suggest that slow expansion of small (< 45 mm) AAAs observed over an isolated 24 month period is indicative of a very low risk of rupture or repair in the medium term. Isolated growth rates may be a useful tool with which to triage low risk AAAs and prevent unnecessary surveillance.

Fast-Track Management of Concurrent Percutaneous Coronary Intervention in Patients Scheduled for Endovascular Abdominal Aortic Aneurysm Repair

PURPOSE

To investigate the safety and efficacy of fast-track management of concurrent percutaneous coronary intervention (PCI) in patients with abdominal aortic aneurysm scheduled for endovascular aortic aneurysm repair (EVAR).

MATERIALS AND METHODS

Eligible patients with abdominal aortic aneurysm who received EVAR from January 2011 to December 2019 were included in this retrospective cohort study. Propensity score (PS)-matched analysis was used to balance the baseline between the fast-track and standard control (EVAR without significant coronary artery disease) groups. Effects of fast-track management on short-term and midterm outcomes were evaluated via Cox proportional hazard regression and logistic regression analyses with corresponding hazard ratio (HR) or odds ratio (OR) and associated 95% confidence intervals (95% CIs), respectively.

RESULTS

The study included 669 patients (73 fast-track and 596 standard control). Compared with the standard control group, no significant difference was found regarding major adverse cardiac events (HR 0.78, 95% CI [0.36, 1.68], p=0.519), overall mortality (HR 0.63, 95% CI [0.25, 1.55], p=0.315), and 30-day major hemorrhage events (OR 1.01, 95% CI [0.99, 1.03], p=0.514). The results were consistent in the PS-matched cohorts regarding major adverse cardiac events (HR 0.57, 95% CI [0.25, 1.29], p=0.176), overall mortality (HR 0.43, 95% CI [0.17, 1.11], p=0.820), and 30-day major hemorrhage events (OR 1.00, 95% CI [0.05, 10.61], p=0.999). Similar results were found in the subgroup analyses concerning fast-track management of 2-week intervals and patients with high age-adjusted Charlson comorbidity index.

CONCLUSIONS

Under appropriate perioperative care, shortening the time interval between PCI and EVAR to 1 month, or even 2 weeks, seemed to be safe and effective. Short-term and midterm cardiovascular and survival outcomes were comparable with patients who underwent standard EVAR without significant coronary artery disease.

Systematic Review and Meta-Analysis of the Incidence of Rupture, Repair, and Death of Small and Large Abdominal Aortic Aneurysms under Surveillance

BACKGROUND

The ultimate goal of treating patients with abdominal aortic aneurysms (AAAs) is to repair them when the risk of rupture exceeds the risk of repair. Small AAAs demonstrate a low rupture risk, and recently, large AAAs just above the threshold (5.5-6.0 cm) seem to be at low risk of rupture as well. The present review aims to investigate the outcomes of AAAs under surveillance through a comprehensive systematic review and meta-analysis.

METHODS

PubMed, Embase, and the Cochrane Central Register were searched (22 March 2022; PROSPERO; #CRD42022316094). The Cochrane and PRISMA statements were respected. Blinded systematic screening of the literature, data extraction, and quality assessment were performed by two authors. Conflicts were resolved by a third author. The meta-analysis of prevalence provided estimated proportions, 95% confidence intervals, and measures of heterogeneity (I2). Based on I2, the heterogeneity might be negligible (0-40%), moderate (30-60%), substantial (50-90%), and considerable (75-100%). The primary outcome was the incidence of AAA rupture. Secondary outcomes included the rate of small AAAs reaching the threshold for repair, aortic-related mortality, and all-cause mortality.

RESULTS

Fourteen publications (25,040 patients) were included in the analysis. The outcome rates of the small AAA group (<55 mm) were 0.3% (95% CI 0.0-1.0; I2 = 76.4%) of rupture, 0.6% (95% CI 0.0-1.9; I2 = 87.2%) of aortic-related mortality, and 9.6% (95% CI 2.2-21.1; I2 = 99.0%) of all-cause mortality. During surveillance, 21.4% (95% CI 9.0-37.2; I2 = 99.0%) of the initially small AAAs reached the threshold for repair. The outcome rates of the large AAA group (>55 mm) were 25.7% (95% CI 18.0-34.3; I2 = 72.0%) of rupture, 22.1% (95% CI 16.5-28.3; I2 = 25.0%) of aortic-related mortality, and 61.8% (95% CI 47.0-75.6; I2 = 89.1%) of all-cause mortality. The sensitivity analysis demonstrated a higher rupture rate in studies including <662 subjects, patients with a mean age > 72 years, >17% of female patients, and >44% of current smokers.

CONCLUSION

The rarity of rupture and aortic-related mortality in small AAAs supports the current conservative management of small AAAs. Surveillance seems indicated, as one-fifth reached the threshold for repair. Large aneurysms had a high incidence of rupture and aortic-related mortality. However, these data seem biased by the sparse and heterogeneous literature overrepresented by patients unfit for surgery. Specific rupture risk stratified by age, gender, and fit-for-surgery patients with large AAAs needs to be further investigated.

The relationship between computed tomography-derived body composition, systemic inflammation, and survival in patients with abdominal aortic aneurysm

OBJECTIVE

Patient selection and risk stratification for elective repair of abdominal aortic aneurysm (AAA), either by open surgical repair or by endovascular aneurysm repair, remain challenging. Computed tomography (CT)-derived body composition analysis (CT-BC) and systemic inflammation-based scoring systems such as the systemic inflammatory grade (SIG) appear to offer prognostic value in patients with AAA undergoing endovascular aneurysm repair. The relationship between CT-BC, systemic inflammation, and prognosis has been explored in patients with cancer, but data in noncancer populations are lacking. The present study aimed to examine the relationship between CT-BC, SIG, and survival in patients undergoing elective intervention for AAA.

METHODS

A total of 611 consecutive patients who underwent elective intervention for AAA at three large tertiary referral centers were retrospectively recruited for inclusion into the study. CT-BC was performed and analyzed using the CT-derived sarcopenia score (CT-SS). Subcutaneous and visceral fat indices were also recorded. SIG was calculated from preoperative blood tests. The outcomes of interest were overall and 5-year mortality.

RESULTS

Median (interquartile range) follow-up was 67.0 (32) months, and there were 194 (32%) deaths during the follow-up period. There were 122 (20%) open surgical repair cases, 558 (91%) patients were male, and the median (interquartile range) age was 73.0 (11.0) years. Age (hazard ratio [HR]: 1.66, 95% confidence interval [CI]: 1.28-2.14, P < .001), elevated CT-SS (HR: 1.58, 95% CI: 1.28-1.94, P < .001), and elevated SIG (HR: 1.29, 95% CI: 1.07-1.55, P < .01) were independently associated with increased hazard of mortality. Mean (95% CI) survival in the CT-SS 0 and SIG 0 subgroup was 92.6 (84.8-100.4) months compared with 44.9 (30.6-59.2) months in the CT-SS 2 and SIG ≥2 subgroup (P < .001). Patients with CT-SS 0 and SIG 0 had 90% (standard error: 4%) 5-year survival compared with 34% (standard error: 9%) in patients with CT-SS 2 and SIG ≥2 (P < .001).

CONCLUSIONS

Combining measures of radiological sarcopenia and the systemic inflammatory response offers prognostic value in patients undergoing elective intervention for AAA and may contribute to future clinical risk predication strategies.

The Treatment of Patients With an Unruptured Abdominal Aortic Aneurysm and a Concomitant Malignancy

BACKGROUND

Having cancer adversely effects the outcome of treatment for an unruptured abdominal aortic aneurysm (AAA).

METHODS

A retrospective secondary analysis was performed on the basis of anonymized data from AOK, a German nationwide statutory healthinsurance carrier. Data were evaluated from all of the 20 683 patients who underwent either endovascular (EVAR, 15 792) or open surgical (OAR, 4891) treatment for an unruptured AAA in the years 2010-2016. It was determined in each case whether the patient had a known cancer at the time of the procedure to treat AAA. The analysis concerned patient characteristics, periprocedural complications, and survival after the procedure up to 31 December 2018.

RESULTS

18 222 patients were free of cancer. In accordance with the known 6:1 sex ratio of AAA, 85.3% of the cancer-free patients and 92.8% of those with cancer were men. At the time of their AAA procedure, 1398 had cancer of the intestine (n = 318), lung (n = 301), prostate (n = 380), or bladder or ureter (n = 399). One-year survival after the AAA procedure was 91.5% in cancer-free patients and 84%, 74.4%, 85.8%, and 85.5% in the patients with the respective types of cancer just mentioned. Having cancer was a significant risk factor for periprocedural mortality (OR 1.326, p = 0.041) and for long-term survival (HR 1.515; p < 0.001).

CONCLUSION

Having cancer is a risk factor for periprocedural mortality and long-term survival in patients undergoing treatment for an unruptured AAA. This implies that the indications for surgery should be considered with care, particularly in patients with lung cancer, whose 5-year survival rate is only 37.2%.

Status of diagnosis and therapy of abdominal aortic aneurysms

Abdominal aortic aneurysms (AAAs) are characterized by localized dilation of the abdominal aorta. They are associated with several serious consequences, including compression of adjacent abdominal organs, pain, treatment-related financial expenditure. The main complication of AAA is aortic rupture, which is responsible for about 200,000 deaths per year worldwide. An increasing number of researchers are dedicating their efforts to study AAA, resulting in significant progress in this field. Despite the commendable progress made thus far, there remains a lack of established methods to effectively decelerate the dilation of aneurysms. Therefore, further studies are imperative to expand our understanding and enhance our knowledge concerning AAAs. Although numerous factors are known to be associated with the occurrence and progression of AAA, the exact pathway of development remains unclear. While asymptomatic at most times, AAA features a highly unpredictable disease course, which could culminate in the highly deadly rupture of the aneurysmal aorta. Current guidelines recommend watchful waiting and lifestyle adjustment for smaller, slow-growing aneurysms, while elective/prophylactic surgical repairs including open repair and endovascular aneurysm repair are recommended for larger aneurysms that have grown beyond certain thresholds (55 mm for males and 50 mm for females). The latter is a minimally invasive procedure and is widely believed to be suited for patients with a poor general condition. However, several concerns have recently been raised regarding the postoperative complications and possible loss of associated survival benefits on it. In this review, we aimed to highlight the current status of diagnosis and treatment of AAA by an in-depth analysis of the findings from literatures.

[Results of a single center vascular screening program in Germany]

BACKGROUND

Cardiovascular diseases are the main cause of death in Europe with a relevant socioeconomic burden. A screening program for vascular diseases in asymptomatic persons with a defined risk constellation can lead to an early diagnosis.

OBJECTIVE

The study examined a screening program for carotid stenosis, peripheral arterial occlusive disease (PAOD) and abdominal aortic aneurysms (AAA) in persons without any known vascular disease with respect to demographic data, risk factors, pre-existing conditions, medication intake, detection of pathological findings and/or findings requiring treatment.

MATERIAL AND METHODS

Test subjects were invited using various information material and filled in a questionnaire on cardiovascular risk factors. The screening took place with measurement of the ABI and duplex sonography as a monocentric prospective single arm study within 1 year. Endpoints were the prevalence of risk factors and pathological and/or results requiring treatment.

RESULTS

A total of 391 persons participated, 36% presented with at least 1 cardiovascular risk factor, 35.5% with 2 and 14.4% with 3 or more. The sonography showed results requiring control with a carotid stenosis of < 50-> 75% or occlusion in 9%. An AAA with a diameter of 3.0-4.5 cm was diagnosed in 0.9% and a pathological ABI < 0.9 or > 1.3 in 12.3%. The indications for a pharmacotherapy were found in 17% and no operation was recommended.

CONCLUSION

The practicability of a screening program for carotid stenosis, PAOD and AAA of a defined risk population was shown. Vascular pathologies that required treatment were hardly found in the catchment area of the hospital. Consequently, the implementation of this screening program in Germany based on the collected data cannot currently be recommended in this form.

Selection criterion for endovascular aortic repair in those with chronic kidney disease

OBJECTIVE

Endovascular aortic repair (EVAR) is the preferred method of repair for abdominal aortic aneurysms (AAAs). However, patients with advanced chronic kidney disease (CKD) are a high-risk group, and it is unknown which patients with CKD benefit from EVAR vs continued surveillance. The purpose of this study was to identify which patients with advanced CKD may benefit from EVAR.

METHODS

The Vascular Quality Initiative Database was utilized to identify elective EVARs for AAAs. Patients were excluded if they underwent urgent or emergent repairs. CKD stages were categorized based on preoperative estimated glomular filtration rate (eGFR) and dialysis status. Predicted 1-year mortality of untreated AAAs was calculated by modifying a validated comorbidity score that predicts 1-year mortality (Gagne Index) without repair. The primary outcome was actual 1-year mortality, which was compared with the predicted 1-year mortality without repair.

RESULTS

A total of 34,926 patient met study criteria. There were differences in Gagne Indices among the varying classes of CKD. Patients with CKD 4 and CKD 5 had the highest 1-year mortality rates, followed by CKD 3b, which was significantly higher than those with CKD 1 and CKD 2. Patients with CKD 4 had no differences between actual 1-year mortality with EVAR and predicted 1-year survival without EVAR across all AAA sizes. Those with CKD 5 had worse actual 1-year survival with EVAR than predicted 1-year survival without EVAR for AAAs <5.5 cm. Patients with CKD 5 only experienced an actual mortality benefit with EVAR compared with predicted 1-year mortality without EVAR for AAAs ≥7.0 cm.

CONCLUSION

The current data suggest that patients with CKD 3b, 4, and 5 represent a high-risk group who may not benefit from elective EVAR utilizing traditional size criteria. Patients with CKD 4 and 5 with AAAs <5.5 cm do not benefit from elective EVAR. In patients with CKD 5, elective EVAR may need to be reserved for AAAs ≥7.0 cm unless there are other concerning anatomic characteristics.

The controlling nutritional status score predicts postoperative mortality in patients with ruptured abdominal aortic aneurysm: a retrospective study

Background

Ruptured abdominal aortic aneurysms (rAAAs) are challenging for vascular surgeons because they have a high mortality rate. In many diseases, nutritional status is closely associated with prognosis. The Controlling Nutritional Status (CONUT) screening tool score is a prognostic factor in some malignant and chronic diseases; however, the impact of nutritional status on rAAA has not yet been reported. In this study, we explored the relationship between the CONUT score and the postoperative prognosis of patients with rAAA.

Methods

This was a retrospective review of 39 patients with rAAA who underwent surgical treatment from March 2018 to September 2021 at one center. Patient characteristics, nutritional status (CONUT score), and postoperative status were recorded. The patients were divided into groups A and B based on the CONUT score. The baseline characteristics of the two groups were compared, and Cox proportional hazards and logistic regression analyses were used to determine independent predictors of mid-term mortality and complications, respectively.

Results

The overall mid-term mortality rate was 28.21% (11/39). Compared with group A, group B had higher intraoperative (P = 0.047) and mid-term mortality (P = 0.033) rates. The univariate analysis showed that age [hazard ratio (HR), 1.098; 95% confidence interval (CI), 1.019-1.182; P = 0.014], CONUT score (HR, 1.316; 95% CI, 1.027-1.686; P = 0.03), and surgical procedure (HR, 0.127; 95% CI, 0.016-0.992; P = 0.049) were associated with mid-term mortality, whereas the multivariate analysis showed that the CONUT score (HR, 1.313; 95% CI, 1.009-1.710; P = 0.043) was an independent predictor of mid-term mortality. The multivariate logistic regression analysis did not reveal any associations with complications. The Kaplan-Meier curves showed that group B had a lower mid-term survival rate (log-rank P = 0.024).

Conclusion

Malnutrition is closely associated with the prognosis of patients with rAAA, and the CONUT score can be used to predict mid-term mortality.

A systematic review summarizing local vascular characteristics of aneurysm wall to predict for progression and rupture risk of abdominal aortic aneurysms

OBJECTIVE

At present, the rupture risk prediction of abdominal aortic aneurysms (AAAs) and, hence, the clinical decision making regarding the need for surgery, is determined by the AAA diameter and growth rate. However, these measures provide limited predictive information. In the present study, we have summarized the measures of local vascular characteristics of the aneurysm wall that, independently of AAA size, could predict for AAA progression and rupture.

METHODS

We systematically searched PubMed and Web of Science up to September 13, 2021 to identify relevant studies investigating the relationship between local vascular characteristics of the aneurysm wall and AAA growth or rupture in humans. A quality assessment was performed using the ROBINS-I (risk of bias in nonrandomized studies of interventions) tool. All included studies were divided by four types of measures of arterial wall characteristics: metabolism, calcification, intraluminal thrombus, and compliance.

RESULTS

A total of 20 studies were included. Metabolism of the aneurysm wall, especially when measured by ultra-small superparamagnetic iron oxide uptake, and calcification were significantly related to AAA growth. A higher intraluminal thrombus volume and thickness had correlated positively with the AAA growth in one study but in another study had correlated negatively. AAA compliance demonstrated no correlation with AAA growth and rupture. The aneurysmal wall characteristics showed no association with AAA rupture. However, the metabolism, measured via ultra-small superparamagnetic iron oxide uptake, but none of the other measures, showed a trend toward a relationship with AAA rupture, although the difference was not statistically significant.

CONCLUSIONS

The current measures of aortic wall characteristics have the potential to predict for AAA growth, especially the measures of metabolism and calcification. Evidence regarding AAA rupture is scarce, and, although more work is needed, aortic wall metabolism could potentially be related to AAA rupture. This highlights the role of aortic wall characteristics in the progression of AAA but also has the potential to improve the prediction of AAA growth and rupture.

Abdominal Aortic Aneurysms (Etiology, Epidemiology, and Natural History)

Abdominal aortic aneurysm is a potentially lethal condition that is decreasing in frequency as tobacco use declines. The exact etiology remains unknown, but smoking and other perturbations seem to trigger an inflammatory state in the tunica media. Male sex and advanced age are clear demographic risk factors for the development of abdominal aortic aneurysms. The natural history of this disease varies, but screening remains vital as it is rarely diagnosed on physical examination, and elective repair (most commonly done endovascularly) offers significant morbidity and mortality advantages over emergent intervention for aortic rupture.

Computed Tomography Angiography Markers and Intraluminal Thrombus Morphology as Predictors of Abdominal Aortic Aneurysm Rupture

Background: Abdominal aortic aneurysm (AAA) is a complex vascular disease characterized by progressive and irreversible local dilatation of the aortic wall. Currently, the indication for repair is linked to the transverse diameter of the abdominal aorta, using computed tomography angiography imagery, which is one of the most used markers for aneurysmal growth. This study aims to verify the predictive role of imaging markers and underlying risk factors in AAA rupture. Methods: The present study was designed as an observational, analytical, retrospective cohort study and included 220 patients over 18 years of age with a diagnosis of AAA, confirmed by computed tomography angiography (CTA), admitted to Vascular Surgery Clinic of Mures County Emergency Hospital in Targu Mures, Romania, between January 2018 and September 2022. Results: Patients with a ruptured AAA had higher incidences of AH (p = 0.006), IHD (p = 0.001), AF (p < 0.0001), and MI (p < 0.0001), and higher incidences of all risk factors (tobacco (p = 0.001), obesity (p = 0.02), and dyslipidemia (p < 0.0001)). Multivariate analysis showed that a high baseline value of all imaging ratios markers was a strong independent predictor of AAA rupture (for all p < 0.0001). Moreover, a higher baseline value of DAmax (OR:3.91; p = 0.001), SAmax (OR:7.21; p < 0.001), and SLumenmax (OR:34.61; p < 0.001), as well as lower baseline values of DArenal (OR:7.09; p < 0.001), DACT (OR:12.71; p < 0.001), DAfemoral (OR:2.56; p = 0.005), SArenal (OR:4.56; p < 0.001), SACT (OR:3.81; p < 0.001), and SThrombusmax (OR:5.27; p < 0.001) were independent predictors of AAA rupture. In addition, AH (OR:3.33; p = 0.02), MI (OR:3.06; p = 0.002), and PAD (OR:2.71; p = 0.004) were all independent predictors of AAA rupture. In contrast, higher baseline values of SAmax/Lumenmax (OR:0.13; p < 0.001) and ezetimibe (OR:0.45; p = 0.03) were protective factors against AAA rupture. Conclusions: According to our findings, a higher baseline value of all imaging markers ratios at CTA strongly predicts AAA rupture and AH, MI, and PAD highly predicted the risk of rupture in AAA patients. Furthermore, the diameter of the abdominal aorta at different levels has better accuracy and a higher predictive role of rupture than the maximal diameter of AAA.

Prognostic model for survival of patients with abdominal aortic aneurysms treated with endovascular aneurysm repair

The role of endovascular aneurysm repair (EVAR) in patients with asymptomatic abdominal aortic aneurysm (AAA) who are unfit for open surgical repair has been questioned. The impending risk of aneurysm rupture, the risk of elective repair, and the life expectancy must be balanced when considering elective AAA repair. This retrospective observational cohort study included all consecutive patients treated with standard EVAR for AAA at a referral centre between 2001 and 2020. A previously published predictive model for survival after EVAR in patients treated between 2001 and 2012 was temporally validated using patients treated at the same institution between 2013 and 2020 and updated using the overall cohort. 558 patients (91.2% males, mean age 74.9 years) were included. Older age, lower eGFR, and COPD were independent predictors for impaired survival. A risk score showed good discrimination between four risk groups (Harrel's C = 0.70). The 5-years survival probabilities were only 40% in "high-risk" patients, 68% in "moderate-to-high-risk" patients, 83% in "low-to-moderate-risk", and 89% in "low-risk" patients. Low-risk patients with a favourable life expectancy are likely to benefit from EVAR, while high-risk patients with a short life expectancy may not benefit from EVAR at the current diameter threshold.

The relationship between pre-operative psoas and skeletal muscle parameters and survival following endovascular aneurysm repair: a systematic review and meta-analysis

Sarcopenia is characterised by chronically reduced skeletal muscle volume and function, and is determined radiologically by psoas and skeletal muscle measurement. The present systematic review and meta-analysis aims to examine the relationship between pre-operative CT-derived psoas and skeletal muscle parameters and outcomes in patients undergoing EVAR and F/B-EVAR for aortic aneurysm. The MEDLINE database was interrogated for studies investigating the effect of pre-operative CT-diagnosed sarcopenia on outcomes following EVAR and F/B-EVAR. The systematic review was carried out in accordance with PRISMA guidelines. The primary outcome was overall mortality. RevMan 5.4.1 was used to perform meta-analysis. PROSPERO Database Registration Number: CRD42021273085. Ten relevant studies were identified, one reporting skeletal muscle parameters, and the remaining nine reporting psoas muscle parameters, which were used for meta-analysis. There were a total of 2563 patients included (2062 EVAR, 501 F/B-EVAR), with mean follow-up ranging from 25 to 101 months. 836 patients (33%) were defined as radiologically sarcopenic. In all studies, the combined HR for all-cause mortality in sarcopenic versus non-sarcopenic patients was 2.61 (1.67–4.08), p < .001. Two studies reported outcomes on patients undergoing F/B-EVAR; the combined HR for all-cause mortality in sarcopenic versus non-sarcopenic patients was 3.08 (1.66–5.71), p = .004. Radiological sarcopenia defined by psoas or skeletal muscle parameters was associated with inferior survival in patients undergoing both EVAR and F/B-EVAR. Current evidence is limited by heterogeneity in assessment of body composition and lack of a consensus definition of radiological sarcopenia.

Contrast-enhanced US Evaluation of Endoleaks after Endovascular Stent Repair of Abdominal Aortic Aneurysm

Ruptured abdominal aortic aneurysm (AAA) carries high morbidity and mortality. Elective repair of AAA with endovascular stent-grafts requires lifetime imaging surveillance for potential complications, most commonly endoleaks. Because endoleaks result in antegrade or retrograde systemic arterialized flow into the excluded aneurysm sac, patients are at risk for recurrent aneurysm sac growth with the potential to rupture. Multiphasic CT has been the main imaging modality for surveillance and symptom evaluation, but contrast-enhanced US (CEUS) offers a useful alternative that avoids radiation and iodinated contrast material. CEUS is at least equivalent to CT for detecting endoleak and may be more sensitive. The authors provide a general protocol and technical considerations needed to perform CEUS of the abdominal aorta after endovascular stent repair. When there are no complications, the stent-graft lumen has homogeneous enhancement, and no contrast material is present in the aneurysm sac outside the stented lumen. In patients with an antegrade endoleak, contrast material is seen simultaneously in the aneurysm sac and stent-graft lumen, while delayed enhancement in the sac is due to retrograde leak. Recognition of artifacts and other potential pitfalls for CEUS studies is important for examination performance and interpretation. Online supplemental material is available for this article. ^©RSNA, 2022.

Reference values of normal abdominal aortic areas in Chinese population measured by contrast-enhanced computed tomography

Objective

To generate reference values of the normal areas of the abdominal aorta at various levels among Chinese people and to explore the factors that may promote the expansion of the abdominal aorta.

Methods

The areas of normal abdominal aortas were gauged at various levels based on inner-to-inner measurements in 1,066 Chinese adult patients (&gt;18 years) without the abdominal aortic disease. The areas of subphrenic abdominal, suprarenal abdominal, infrarenal abdominal, and distal abdominal aortas were measured. The demographic and clinical characteristics were collected into a specifically designed electronic database. Multivariable linear regression was used to analyze the potential risk factors promoting the expansion of the abdominal aorta.

Results

In males, the median areas of the subphrenic abdominal aorta, suprarenal abdominal aorta, infrarenal abdominal aorta, and distal abdominal aorta were 412.1, 308.0, 242.2, and 202.2 mm2, respectively. In females, the median areas of the subphrenic abdominal aorta, suprarenal abdominal aorta, infrarenal abdominal aorta, and distal abdominal aorta were 327.7, 243.4, 185.4, and 159.6 mm2, respectively. The areas of the abdominal aorta at different levels were larger in males than in females and increased with age. Multiple linear stepwise regression analysis showed that the subphrenic abdominal aortic area was significantly related to age (β = 0.544, p &lt; 0.001), sex (β = 0.359, p &lt; 0.001), and hypertension (β = 0.107, p &lt; 0.001). Suprarenal abdominal aortic area was related to age (β = 0.398, p &lt; 0.001), sex (β = 0.383, p &lt; 0.001), history of smoking (β = 0.074, p = 0.005), and hypertension (β = 0.111, p &lt; 0.001). The infrarenal abdominal aortic area was correlated with age (β = 0.420, p &lt; 0.001), sex (β = 0.407, p &lt; 0.001), and history of smoking (β = 0.055, p = 0.036). The distal abdominal aortic area was correlated with age (β = 0.463, p &lt; 0.001), sex (β = 0.253, p &lt; 0.001), and hypertension (β = 0.073, p = 0.013).

Conclusion

The abdominal aortic areas at different levels were larger in males than in females. Aging, hypertension, and smoking prompt the expansion of abdominal aorta.

Giant Symptomatic Unruptured Juxtarenal Abdominal Aortic Aneurysm

Herein, we present the case of an 84-year-old male with a 13-cm, symptomatic, unruptured juxtarenal abdominal aortic aneurysm. This aneurysm was successfully treated with open surgical repair, which was deemed satisfactory at the 3-year follow-up. Despite a paradigm shift towards endovascular techniques in aortic repair, postgraduate training with a focused exposure to open aortic surgery at high-volume centers is essential for future vascular surgeons to safely perform complex aortic repairs with acceptable mortality and morbidity rates.

Editor's Choice - Risk of Rupture and All Cause Mortality of Abdominal Aortic Ectasia: A Systematic Review and Meta-Analysis

OBJECTIVE

To clarify the natural history of abdominal aortic ectasia (AAE) measuring 25 - 29 mm in maximum diameter, and to determine the optimal follow up based on the growth, risk of rupture, and overall mortality of AAE.

DATA SOURCES

MEDLINE, Web of Science Core Collection, and Google Scholar.

REVIEW METHODS

This was a systematic review and meta-analysis of AAE in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. MEDLINE, Web of Science Core Collection, and Google Scholar were searched, with the help of a health sciences librarian, up to 11 August 2021. Studies with longitudinal outcomes of AAE (prevalence, annual growth rate, aneurysmal enlargement, rupture, aneurysm related death, and all cause mortality) were included. Meta-analyses were conducted with a random effects model RESULTS: Twelve studies describing a total of 8 369 patients were eligible. The prevalence at population based settings was 3.2% (95% confidence interval [CI] 2.4 - 4.0); annual growth rate was 0.82 mm/year (95% CI 0.20 - 1.45). The estimated risks of aortic diameters exceeding 30 mm and 55 mm in five years were 45.0% (95% CI 28.5 - 61.5) and 0.3% (95% CI 0 - 0.6) respectively, while those beyond five years were 70.2% (95% CI 46.9 - 93.6) and 5.2% (95% CI 2.2 - 8.2). The rates of rupture and aneurysm related death were minimal until five years (0.1% and 0.1%, respectively) and beyond (0.4% and 0.2%, respectively). Overall mortality was 7.5% (95% CI 3.9 - 11.0) and 17.3% (95% CI 9.5 - 25.1) up to and beyond five years. Overall mortality from three studies showed no statistical difference between AAE and aneurysms (hazard ratio 0.62, 95% CI 0.32 - 1.21; p = .16). Cancer (35.0%) and cardiovascular diseases (31.9%) were major causes of death.

CONCLUSION

AAE carries minimal risk of aneurysm related lethal events during the first five years, but a similar overall mortality risk as abdominal aortic aneurysm. Cancer and cardiovascular diseases are leading causes of death in patients with AAE.

EVALUATION OF AORTIC TORTUOSITY AS A NEGATIVE PREDICTOR OF ABDOMINAL AORTIC ANEURYSM RUPTURE

OBJECTIVE

Maximal aortic diameter has been used as a key indication to repair an abdominal aortic aneurysm (AAA). Aortic tortuosity has been proposed as another consideration. This study compared the degree of aortic tortuosity in ruptured aneurysms with those who underwent elective repair using CT imaging.

METHODS

A retrospective review of a prospectively maintained database of patients that underwent AAA repair from Dec 2014 to Dec 2019 was undertaken. Patients with ruptured aneurysm (rAAA) were matched to a group of non-ruptured AAA (nrAAA) patients with the same maximal aneurysm diameter and age. The degree of aortic tortuosity, defined as the maximum lateral deviation (mm) from aortic centerline, was measured on preoperative CT scans on coronal views.

RESULTS

Over a 5-year period, 572 AAA cases were identified. The aortic tortuosity of 25 rAAA cases were compared with a matched control group of 31 nrAAA that were selected based on same mean maximum diameter of 8.4cm and similar age. In the rAAA group, the mean age was 74.8 years (84% males). For the nrAAA group, the mean age was 76.3 years (88%) males. The mean aortic tortuosity for the rAAA cases and nrAAA groups were 9.3±7.9 mm and 18.0±11.2 mm, respectively (p<0.01).

CONCLUSIONS

Greater aortic tortuosity was seen in nrAAA cases compared with rAAA cases at the same matched aneurysm size. This suggests that aortic tortuosity may confer a reduced rupture risk. Further studies with larger cohorts are needed to verify this observation.

Racial and Ethnic Disparities in Abdominal Aortic Aneurysm Evaluation and Treatment Rates in Texas

INTRODUCTION

Screening identifies intact abdominal aortic aneurysm (iAAA) before progression to ruptured AAA (rAAA). However, screening efforts have been limited by low overall diagnostic yield and by unequal screening among minority populations. The goal was to identify equitable AAA screening strategies for both majority and minority populations.

METHODS

We performed epidemiological and geospatial analyses of inpatient and outpatient procedures for iAAA or rAAA at Texas hospitals from 2006 through 2014 at all non-federal hospitals and clinics in Texas. Data were aggregated by area (metropolitan statistical area or rural region), then supplemented by six additional data sources to estimate AAA repair incidence rates, rates of AAA-related clinic and ultrasonography visits, distance to providers, and location and number of unrecognized AAAs.

RESULTS

The majority of AAA repairs occurred among 65-84 year-old men in large metropolitan areas categorized as White. Area procedure rates for rAAA and iAAA were strongly correlated (R²=0.47). Two other variables-the proportions of persons categorized as White and persons aged ≥65 years in a region-identified subgroups within the majority population that were at high risk for iAAA (R²=0.46). Lower rates of clinic visits and AAA ultrasonograms were seen among persons categorized as Black. The several areas with disproportionately-higher rAAA:iAAA ratios were found, mainly affecting persons categorized as Black.

CONCLUSIONS

Multiple focused AAA screening strategies may be needed to address disproportionately-lower AAA identification among persons categorized as Black.

Abdominal Aortic Screening Is a Priority for Health in Smoker Males: A Study on Central Italian Population

Abdominal aortic aneurysm (AAA) is a major public health problem. In the last decade, in some European countries, abdominal aortic screening (AAS) is emerging as a potential prevention for the rupture of AAA. The goals of our study were to estimate AAA prevalence and risk factors in males and females in a central Italian population, also defining the cost-effectiveness of AAS programs. A pilot study screening was conducted between 1 January 2015 and 31 December 2019 in the municipality of Teramo (Abruzzo Region, Italy) in a group of men and women, ranging from the age of 65 to 79, who were not previously operated on for AAA. The ultrasound was performed by means of Acuson sequoia 512 Simens with a Convex probe. The anterior posterior of the infra-renal aorta was evaluated. The odds ratio values (ORs) were used to evaluate the risk of AAA, and the following determinants were taken into consideration: gender, smoke use, hypertension, and ischemic heart disease. We also estimated the direct costs coming from aneurysmectomy (surgical repair or endovascular aneurysms repair-EVAR). A total of 62 AAA (2.7%, mean age 73.8 ± 4.0) were diagnosed, of which 57 were in men (3.7%, mean age 73.6 ± 4.0) and 5 were in women (0.7%, mean age 74.3 ± 4.1). Male gender and smoke use are more important risk factors for AAA ≥ 3 cm, respectively: OR = 5.94 (2.37-14.99, p < 0.001) and OR = 5.21 (2.63-10.30, p < 0.000). A significant increase in OR was noted for AAA ≥ 3 cm and cardiac arrhythmia and ischemic heart disease, respectively: OR = 2.81 (1.53-5.15, p < 0.000) and OR = 2.76 (1.40-5.43, p = 0.006). Regarding the cost analysis, it appears that screening has contributed to the reduction in costs related to urgency. In fact, the synthetic indicator given by the ratio between the DRGs (disease related group) relating to the emergency and those of the elective activity went from 1.69 in the year prior to the activation of the screening to a median of 0.39 for the five-year period of activation of the screening. It is important to underline that the results of our work confirm that the screening activated in our territory has led to a reduction in the expenditure for AAA emergency interventions, having increased the planned interventions. This must be a warning for local stakeholders, especially in the post-pandemic period, in order to strengthen prevention.

Molecular Imaging of Abdominal Aortic Aneurysms with Positron Emission Tomography: A Systematic Review

OBJECTIVE

Previous studies on the relationship between positron emission tomography (PET) images and abdominal aortic aneurysm (AAA) progression have shown contradictory results, and the objective of this study was to systematically review the role of PET in predicting AAA prognosis.

DATA SOURCES

PubMed, Embase, and Web of Science were searched for studies evaluating the correlation between PET imaging results and AAA growth, repair, or rupture.

REVIEW METHODS

Two authors independently performed the study search, data extraction, and quality assessment following a standard method.

RESULTS

Of the 11 studies included in this review, nine used ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) PET and computed tomography (CT) imaging, whereas the remaining two used ¹⁸F-sodium fluoride (¹⁸F-NaF) PET/CT and ¹⁸F-FDG PET/magnetic resonance imaging (MRI). Findings from the ¹⁸F-FDG PET/CT studies were contradictory. Six studies found no significant association or correlation, and two studies found a significant negative correlation between ¹⁸F-FDG uptake and AAA expansion. Additionally, one study found that the ¹⁸F-FDG uptake was statistically positively related to the expansion rate in a specific AAA subgroup whose AAAs expanded significantly. Two studies suggested that increased ¹⁸F-FDG uptake was significantly associated with AAA repair, while the other studies either found no association between ¹⁸F-FDG uptake and AAA rupture or repair or failed to report the occurrence of clinical events. One PET/CT study that used ¹⁸F-NaF as a tracer showed that an increased tracer uptake was significantly associated with AAA growth and clinical events. Finally, the ¹⁸F-FDG PET/MRI study indicated that ¹⁸F-FDG uptake was not significantly correlated with AAA expansion.

CONCLUSION

A definitive role for ¹⁸F-FDG PET imaging for AAA prognosis awaits further investigation, and new PET tracers such as ¹⁸F-NaF have the potential to be a promising method for predicting AAA clinical outcomes.

The Short-term Predictive Value of Vessel Wall Stiffness on Abdominal Aortic Aneurysm Growth

BACKGROUND

Abdominal aortic aneurysm (AAA) surveillance programs are currently based solely on AAA diameter. The diameter criterion alone, however, seems inadequate as small AAAs comprise 5-10 % of ruptured AAAs as well as some large AAAs never rupture. Aneurysm wall stiffness has been suggested to predict rupture and growth; this study aimed to investigate the prognostic value of AAA vessel wall stiffness for growth on prospectively collected data.

METHODS

Analysis was based on data from a randomised, placebo-controlled, multicentre trial investigating mast-cell-inhibitors to halt aneurysm growth (the AORTA trial). Systolic and diastolic AAA diameter was determined in 326 patients using electrocardiogram-gated ultrasound (US). Stiffness was calculated at baseline and after 1 year.

RESULTS

Maximum AAA diameter increased from 44.1 mm to 46.5 mm during the study period. Aneurysm growth after 1 year was not predicted by baseline stiffness (-0.003 mm/U; 95 % CI: -0.007 to 0.001 mm/U; P = 0.15). Throughout the study period, stiffness remained unchanged (8.3 U; 95 % CI: -2.5 to 19.1 U; P = 0.13) and without significant correlation to aneurysm growth (R: 0.053; P = 0.38).

CONCLUSIONS

Following a rigorous US protocol, this study could not confirm AAA vessel wall stiffness as a predictor of aneurysm growth in a 1-year follow-up design. The need for new and subtle methods to complement diameter for improved AAA risk assessment is warranted.

The natural history of large abdominal aortic aneurysms in patients without timely repair

OBJECTIVE

Contemporary data on the natural history of large abdominal aortic aneurysms (AAAs) in patients undergoing delayed or no repair are lacking. In this study, we examine the impact of large AAA size on the incidence of rupture and mortality.

METHODS

From a prospectively maintained aneurysm surveillance registry, patients with an unrepaired, large AAA (≥5.5 cm in men and ≥5.0 cm in women) at baseline (ie, index imaging) or who progressed to a large size from 2003 to 2017 were included, with follow-up through March 2020. Outcomes of interest obtained by manual chart review included rupture (confirmed by imaging/autopsy), probable rupture (timing/findings consistent with rupture without more likely cause of death), repair, reasons for either no or delayed (>1 year after diagnosis of large AAA) repair and total mortality. Cumulative incidence of rupture was calculated using a nonparametric cumulative incidence function, accounting for the competing events of death and aneurysm repair and was stratified by patient sex.

RESULTS

Of the 3248 eligible patients (mean age, 83.6 ± 9.1 years; 71.2% male; 78.1% white; and 32.0% current smokers), 1423 (43.8%) had large AAAs at index imaging, and 1825 progressed to large AAAs during the follow-up period, with a mean time to qualifying size of 4.3 ± 3.4 years. In total, 2215 (68%) patients underwent repair, of which 332 were delayed >1 year; 1033 (32%) did not undergo repair. The most common reasons for delayed repair were discrepancy in AAA measurement between surgeon and radiologist (34%) and comorbidity (20%), whereas the most common reasons for no repair were patient preference (48%) and comorbidity (30%). Among patients with delayed repair (mean time to repair, 2.6 ± 1.8 years), nine (2.7%) developed symptomatic aneurysms, and an additional 11 (3.3%) ruptured. Of patients with no repair, 94 (9.1%) ruptured. The 3-year cumulative incidence of rupture was 3.4% for initial AAA size 5.0 to 5.4 cm (women only), 2.2% for 5.5 to 6.0 cm, 6.0% for 6.1 to 7.0 cm, and 18.4% for >7.0 cm. Women with AAA size 6.1 to 7.0 cm had a 3-year cumulative incidence of rupture of 12.8% (95% confidence interval, 7.5%-19.6%) compared with 4.5% (95% confidence interval, 3.0%-6.5%) in men (P = .002).

CONCLUSIONS

In this large cohort of AAA registry patients over 17 years, annual rupture rates for large AAAs were lower than previously reported, with possible increased risk in women. Further analyses are ongoing to identify those at increased risk for aneurysm rupture and may provide targeted surveillance regimens and improve patient counseling.

Aberrant Mitochondrial Dynamics: An Emerging Pathogenic Driver of Abdominal Aortic Aneurysm

Abdominal aortic aneurysm (AAA) is defined as a progressive segmental dilation of the abdominal aorta and is associated with high mortality. The characterized features of AAA indicate several underlying mechanisms of AAA formation and progression, including reactive oxygen species production, inflammation, and atherosclerosis. Mitochondrial functions are critical for determining cell fate, and mitochondrial dynamics, especially selective mitochondrial autophagy, which is termed as mitophagy, has emerged as an important player in the pathogenesis of several cardiovascular diseases. The PARKIN/PARIS/PGC1α pathway is associated with AAA formation and has been proposed to play a role in mitochondrial dynamics mediated by the PINK/PARKIN pathway in the pathogenesis underlying AAA. This review is aimed at deepening our understanding of AAA formation and progression, which is vital for the development of potential medical therapies for AAA.

Vascular Deformation Mapping of Abdominal Aortic Aneurysm

Abdominal aortic aneurysm (AAA) is a complex disease that requires regular imaging surveillance to monitor for aneurysm stability. Current imaging surveillance techniques use maximum diameter, often assessed by computed tomography angiography (CTA), to assess risk of rupture and determine candidacy for operative repair. However, maximum diameter measurements can be variable, do not reliably predict rupture risk and future AAA growth, and may be an oversimplification of complex AAA anatomy. Vascular deformation mapping (VDM) is a recently described technique that uses deformable image registration to quantify three-dimensional changes in aortic wall geometry, which has been previously used to quantify three-dimensional (3D) growth in thoracic aortic aneurysms, but the feasibility of the VDM technique for measuring 3D growth in AAA has not yet been studied. Seven patients with infra-renal AAAs were identified and VDM was used to identify three-dimensional maps of AAA growth. In the present study, we demonstrate that VDM is able to successfully identify and quantify 3D growth (and the lack thereof) in AAAs that is not apparent from maximum diameter. Furthermore, VDM can be used to quantify growth of the excluded aneurysm sac after endovascular aneurysm repair (EVAR). VDM may be a useful adjunct for surgical planning and appears to be a sensitive modality for detecting regional growth of AAAs.

Proteomics applications in biomarker discovery and pathogenesis for abdominal aortic aneurysm

Introduction: Abdominal aortic aneurysm (AAA) is a common, complex, and life-threatening disease. Currently, the pathogenesis of AAA is not well understood. No biomarkers or specific drugs are available for AAA in clinical applications. Proteomics is a powerful tool in biomarker discovery, exploration of pathogenesis, and drug target identification.Areas covered: We review the application of mass spectrometry-based proteome analysis in AAA patients within the last ten years. Differentially expressed proteins associated with AAA were identified in multiple sample sources, including vascular tissue, intraluminal thrombus, tissue secretome, blood, and cells. Some potential disease biomarkers, pathogenic mechanisms, or therapeutic targets for AAA were discovered using proteome analysis. The challenges and prospects of proteomics applied to AAA are also discussed.Expert opinion: Since most of the previous proteomic studies used relatively small sample sizes, some promising biomarkers need to be validated in multicenter cohorts to accelerate their clinical application. With the rapid development of mass spectrometry technology, modification-specific proteomics and multi-omics research in the future will enhance our understanding of the pathogenesis of AAA and promote biomarker discovery and drug development for clinical translation.