Management of abdominal aortic aneurysms clinical practice guidelines of the European society for vascular surgery

Expand the Success of Screening to Reduce Aortic Aneurysm Mortality - Progress Interpretation and New Fronts

Aortic aneurysm is a leading cause of death across the world. Many victicms carry it without knowing. Ruputre of aortic aneurysms leads to devastating sudden death. This brings trauma to families and our society. Based upon sound results out of several cohort studies, US Preventative Services Task Force (USPST) crafted the 1st nationwide abdominal aorta aneurysm (AAA) screening program in 2005. It was renewed and expanded in each of the subsequent revisions in 2014 and 2019. UK and Sweden estalished their own programs as well. Since then, a significant decline in AAA prevalence and mortality is observed. Two decades into the practice, the state of the art on diagonstics, surgical approaches, and pharmacological options have drastically changed. Patients previously ineligible for treatment or inconclusive on diagnostics now have valid options. The screening program is on the verge for a bold expansion. In this review, we summarized the chroncles leading to the inception of the screening programs, progress interpretation after implementation including gains, gaps and controversies, advents of new technologies and approaches, new fronts facing us, as well as priorities to be addressed in future phases. Particularly, screening asssys with a clinically tested biomarker, tetrahydrobiopterin (H4B), enables unpresended accessibility, consistency and throughput to accommodate the needs of a larger population. Furthermore, patients with AAAs at size below the eligibility threhold for surgical intervention (e.g., < 5.5 cm) can be treated with novel oral medications. Confronting factors such as changing demographics and COVID-19 aftermath are putting up new challenges. Nevertheless, running a program at this scale demands both unwavering commitment and agile fine-tuning. Technical innovation will be an indispensable chapter of its continued success. The burden of aortic aneurysm-led sudden death is too heavy for any family and the society to bear; it is time to step up our resolve with additional capacities as discussed in the present review.

The correlation between the number of endothelial progenitor cells in the peripheral blood and abdominal aortic aneurysm

This study was to investigate the correlation between the number of endothelial progenitor cells (EPCs) in peripheral blood and abdominal aortic aneurysm (AAA), and provide a potential biomarker for the diagnosis and treatment monitoring of AAA. Patients with AAA evaluated in the First Affiliated Hospital of Soochow University from June 2018 to October 2018 (n = 7) were included in this study. All patients were confirmed as AAA by vascular CTA with an increase of more than 50% of the abdominal aortic diameter. Patients (n = 7) with normal abdominal aorta diameter were included as control group with matching age, sex, blood pressure, and blood sugar concentration between experimental and control groups. Mononuclear cells were collected by density gradient centrifugation, stained by CD34-FITC and CD309-PE antibodies, and analyzed by flow cytometry. The number of EPCs in the peripheral blood of patients with AAA (0.874 ± 0.129‰) was significantly lower than that in the control group (1.420 ± 0.289‰) (P < .01). The number of EPCs may be used as a potential biomarker for the diagnosis and monitoring of AAA following treatment.

Anesthesia choice for frail patients undergoing endovascular repair of nonruptured infrarenal abdominal aortic aneurysms

BACKGROUND

Althugh general anesthesia is the predominant choice in endovascular aneurysm repair (EVAR), recent studies have suggested that locoregional anesthesia could be a viable alternative for suitable patients. Frailty has been identified as an independent predictor of increased mortality and morbidity in EVAR. However, the choice of anesthesia in frail patients undergoing EVAR has not been explored.

METHODS

This study aimed to compare the 30-day outcomes of nonemergent intact infrarenal EVAR in frail patients receiving either locoregional or general anesthesia. Patients who underwent infrarenal EVAR were identified in the American College of Surgeons National Surgical Quality Improvement Program database from 2012 to 2022. Frail patients were selected by five-item Modified Frailty Index of ≥2. Exclusion criteria included age <18 years, ruptured abdominal aortic aneurysm (AAA), emergency, and acute intraoperative conversion to open. A one:one propensity score matching strategy was used to match demographics, baseline characteristics, aneurysm diameter, distal aneurysm extent, and concomitant procedures between patients under locoregional and general anesthesia. Thirty-day postoperative outcomes were evaluated.

RESULTS

Among 16,438 patients who underwent EVAR, 4812 (29.27%) were frail. Among the frail patients, 483 (10.04%) were under locoregional anesthesia and 4329 (89.96%) were under general anesthesia. After propensity score matching, patients under locoregional or general anesthesia had comparable 30-day mortality (2.07% vs 2.48%; P = .83) or any complications.

CONCLUSIONS

Locoregional and general anesthesia were found to have comparable postoperative outcomes in frail patients undergoing EVAR unruptured AAA, which did not align with the suggestion that locoregional anesthesia might be more advantageous in frail patients. Although the patient's preferences should be considered, the choice of anesthesia should still be individualized to take into account the patient's age, comorbidities, AAA anatomy, and the complexity of the case, as well as previous surgical and anesthesia experiences.

Local Morphologic and Hemodynamic Analyses for the Prediction of Abdominal Aortic Aneurysm Rupture Based on Patient-Specific CTA and Computational Modeling

OBJECTIVE

Extensive research has focused on the evaluation of rupture risks in abdominal aortic aneurysms (AAAs) through comprehensive morphologic and hemodynamic analyses, primarily considering the AAA as a whole entity. This study tried to identify the high-risk rupture sites of AAAs more precisely before the fatal process based on morphologic and hemodynamic analyses at the local segment.

METHODS

Computed tomography angiography of a specific AAA patient was conducted at the follow-up 4 months before rupture, 1 day before rupture, the day of the rupture, and 15 days after endovascular aortic repair. The evolution of local morphology and the hemodynamic characteristics at these critical timepoints were investigated based on patient-specific reconstructions and computational fluid dynamics.

RESULTS

The morphologic and hemodynamic parameters of the rupture region vary continuously in the process of AAA development and rupture. The surface area and volume of the rupture segment were gradually enlarged at the follow-up 4 months before rupture (47.33 cm2; 67.35 mL), 1 day before rupture (57.23 cm2; 85.24 mL), and on the day of the rupture (62.41cm2; 104.73ml). A prominent decrease in time-averaged wall shear stress and velocity for the rupture segment is observed. The percentages of the lowest time-averaged wall shear stress (<0.1 Pa) area are increased in the AAA region (20.42%, 33.85%, and 53.00%, separately).

CONCLUSIONS

The results based on precisely rebuilt geometries for the complete follow-ups of patient-specific computed tomography angiography demonstrate that notable morphologic and hemodynamic evolutions have occurred in the local segment of the AAA, which was further proved at the rupture site. The significant changes occurring at the local segment may provide valuable information for the evaluation of aneurysm rupture risk and locate the most probable site of rupture.

CLINICAL IMPACT

Capturing the entire process of AAA rupture through CTA imaging is a rare occurrence in clinical practice. The evolution of morphology and hemodynamic characteristics observed in the illustrated results provides valuable insights for clinicians to monitor the state of AAA from a different perspective. These findings suggest that variations in morphology and hemodynamics within the local segment of the AAA might serve as an alternative approach for predicting the rupture risk of AAA.

A Decade-Long Retrospective Study of Factors Influencing Survival in Ruptured Abdominal Aortic Aneurysm

Background: Ruptured abdominal aortic aneurysm (rAAA) carries a high mortality risk, requiring rapid diagnosis and intervention. This study assesses various clinical factors influencing rAAA management outcomes in alignment with evolving guidelines from 2011 to 2024. Methods: A retrospective analysis of 62 rAAA patients treated at Vivantes Clinic, Berlin, from July 2014 to May 2024 was conducted. Data were obtained from medical records, focusing on vital parameters at admission and during treatment. Both numerical and categorical variables were analyzed to identify survival determinants. Results: The overall survival rate was 55%. Significant differences in systolic and diastolic blood pressures during surgery were noted between survivors and non-survivors, with lower pressures observed in non-survivors at critical surgical stages. Other vital signs showed no significant variations. Survival was significantly associated with gender, fluid therapy, and aneurysm location. Conclusions: Effective blood pressure management during surgery is crucial for improving survival in rAAA cases. This study emphasizes adherence to current clinical guidelines and highlights the need for ongoing research to fill existing knowledge gaps. Further investigations are essential to enhance patient care and outcomes in rAAA.

Causal association between Neuroticism and risk of aortic aneurysm: A bidirectional two-sample Mendelian randomization study

BACKGROUND

The objective of this study was to analyze the causal relationship between Neuroticism and aortic aneurysm using Mendelian randomization (MR). The study aimed to establish a foundation for the development of effective prevention and treatment strategies.

METHODS

Genetic association data for Neuroticism were obtained from the UK Biobank, which included 393,411 individuals and 11,968,760 single nucleotide polymorphisms (SNPs). Genetic association data for aortic aneurysm were obtained from a genome-wide association study (GWAS), which included 479,194 individuals and 24,191,825 SNPs. Heterogeneity was assessed using the Cochran's Q statistic test. The study also utilized the MR Pleiotropy RESidual Sum and Outlier (Mr-PRESSO) test, as well as the MR-Egger regression method, to examine horizontal pleiotropy and determine the reliability of the findings through the leave-one-out method.

RESULTS

Forward MR analysis showed that the risk of aortic aneurysm was elevated in individuals with genetically predicted Neuroticism compared to those without Neuroticism (OR = 1.1315, 95 % CI: 1.0269-1.2468; P = 0.0126). The Cochran's Q test showed no heterogeneity (P > 0.05), and the MR-PRESSO test did not identify instrumental variables of horizontal pleiotropy (P > 0.05). The MR analysis remained robust after removing SNPs one by one. Inverse MR analysis did not observe an association between aortic aneurysm and having Neuroticism OR = 1.030, 95 % CI: 0.9459-1.118, P = 0.488).

CONCLUSION

Our study has established a clear causal relationship between genetically determined Neuroticism and the development of aortic aneurysms. It is therefore important to intensify screening and prevention efforts for aortic aneurysms in neurotic patients. It also opens new avenues for exploring the disease's pathogenesis.

Psoas muscle analysis as a surrogate marker of sarcopenia and frailty: A multicenter analysis of predictive capacities over short- and long-term outcomes after abdominal aortic aneurysm repair

OBJECTIVES

Several predictive models exist for estimating the postoperative risks of abdominal aortic aneurysm (AAA) repair, although no particular tool has seen widespread use. We present the results of a multicenter, historic cohort study comparing the predictive capacity of the psoas muscle area (PMA), radiodensity (PMD), and lean muscle area (LMA) as surrogate markers of sarcopenia, over short- and long-term outcomes after AAA repair, compared to the mFI-5 and American Society of Anesthesiologists (ASA) scales.

METHODS

Retrospective review was conducted of all consecutive AAA elective repair cases (open or endovascular) in three tertiary-care centers from 2014 to 2019. Cross-sectional PMA, PMD, and LMA at the mid-body of the L3 vertebra were measured by two independent operators in the preoperative computed tomography. Receiver operating characteristic (ROC) curves were used to determine optimal cutoff values. Bivariate analysis, logistic regression, and Cox's proportional hazards models were built to examine the relationship between baseline variables and postoperative mortality, long-term mortality, and complications.

RESULTS

596 patients were included (mean age 72.7 ± 8 years, 95.1% male, 66.9% EVAR). Perioperative mortality was 2.3% (EVAR 1.2% vs open repair 4.6%, p = .015), and no independent predictors could be identified in the multivariate analysis. Conversely, an age over 74 years old (OR 1.84 95%CI 1.25-2.70), previous heart diseases (OR 1.62 95%CI 1.13-2.32), diabetes mellitus (OR 1.61 95%CI 1.13-2.32), and a PMD value over 66 HU (OR 0.58 95%CI 0.39-0.84) acted as independent predictors of long-term mortality in the Cox's proportional hazards model. Heart diseases (congestive heart failure or coronary artery disease), serum creatinine levels over 1.05 mg/dL, and an aneurysm diameter over 60 mm were independent predictors of major complications.

CONCLUSION

Surrogate markers of sarcopenia had a poor predictive profile for postoperative mortality after AAA repair in our sample. However, PMD stood out as an independent predictor of long-term mortality. This finding can guide future research and should be confirmed in larger datasets.

Long-Term Outcomes in Patients Managed with the EndurantTM Endograft under Elective Setting

Background/Objectives: Device selection during endovascular aneurysm repair (EVAR) for abdominal aortic aneurysms (AAAs) remains an important issue for ensuring endograft durability. This study evaluated the early and follow-up outcomes of elective EVAR with the Endurant platform. Methods: A single-center retrospective analysis was conducted including consecutive elective EVAR procedures with the Endurant II/IIs (2008 to 2024) device. Primary outcomes were technical success, mortality and major complications at 30 days. Survival, endoleak I/III and freedom from reintervention were secondary outcomes. Cox proportional hazards models were employed for risk-adjusted follow-up outcomes. Results: In total, 361 patients were included (72.7 ± 7 years; 96% males; mean AAA diameter 62 ± 14 mm); 92% received a bifurcated device, and 89% conformed to the instructions for use. Technical success was 99.7%. Intra-operative adjunctive procedures included 4.4% proximal cuffs and 1.7% endoanchors. The thirty-day mortality rate was 0.6%, and the major complication rate was 4.1%. Survival was 81% (SE 4.8%), 72% (SE 6.4%) and 52% (SE 9.2%) at 4, 6 and 8 years, with aneurysm-related mortality at 1.7%. Freedom from endoleak Ia was 76% (SE 7.3%) at 6 years, freedom from endoleak Ib was 79% (SE 7.4%) at 7 years and freedom from endoleak III was 94% (SE 3.7%) at 5 years. Freedom from reintervention was 71% (SE 6.1%) and 55% (SE 7.9%) at 5 and 7 years, respectively. No device-related co-factor affected long-term outcomes. Conclusions: Endurant II/IIs endograft is a safe and effective EVAR solution with excellent early outcomes and low long-term aneurysm-related mortality. The need for reintervention in the long term affected less than 50% of cases.

Ultrasound Probe Pressure Affects Aortic Wall Stiffness: A Patient-Specific Computational Study in Abdominal Aortic Aneurysms

PURPOSE

Ultrasound imaging is key in the management of patients with an abdominal aortic aneurysm (AAA). It was recently shown that the cyclic diameter variations between diastole and systole, which can be quantified with US imaging, increase significantly with the strength of the applied probe pressure on the patient's abdomen. The goal of this study is to investigate this effect more thoroughly.

METHODS

With finite-element modeling, pulsatile blood pressure and probe pressure are simulated in three patient-specific geometries. Two distinct models for the aortic wall were simulated: a nonlinear hyperelastic and a linear elastic model. In addition, varying stiffness was considered for the surrounding tissues. The effect of light, moderate, and firm probe pressure was quantified on the stresses and strains in the aortic wall, and on two in vivo stiffness measures. In addition, the Elasticity Loss Index was proposed to quantify the change in stiffness due to probe pressure.

RESULTS

Firm probe pressure decreased the measured aortic stiffness, and material stiffness was affected only when the wall was modeled as nonlinear, suggesting a shift in the stress-strain curve. In addition, stiffer surrounding tissues and a more elongated aneurysm sac decreased the responsiveness to the probe pressure.

CONCLUSION

The effect of probe pressure on the AAA wall stiffness was clarified. In particular, the AAA wall nonlinear behavior was found to be of primary importance in determining the probe pressure response. Thus, further work will intend to make use of this novel finding in a clinical context.

Surgical Treatment for Sac Expansion Caused by Type II Endoleaks after Endovascular Aneurysm Repair of Abdominal Aortic Aneurysms/Iliac Aneurysms

BACKGROUND

This study aimed to examine the outcomes of open surgery techniques involving sacotomy and suturing of the feeding vessels in patients with aneurysm sac expansion after endovascular aneurysm repair (EVAR).

METHODS

Fourteen consecutive patients treated with sacotomy and suturing of feeding vessels for expanding aneurysm sacs with type II endoleaks following EVAR, between January 2018 and December 2022, were retrospectively included. All patients underwent preoperative digital subtraction angiography, and attempts were made to embolize the thick feeding vessels to reduce intraoperative bleeding. Age, sex, comorbidities, clinical presentation, aneurysm sac increase, morbidity, mortality, and follow-up were recorded.

RESULTS

The median age of the patients was 72.89 ± 5.13 years old, and 13 (92.9%) patients were male. The sac size at the time of the open procedure was 107.89 ± 22.58 mm, and the extent of sac growth at the time of the open procedure was 37.50 ± 18.29 mm. The initial technical success rate of laparotomy and open ligation of the culprit arteries causing type II endoleaks was 92.9% (13/14). Among the patients, 5 (35.7%) had been treated with interventional embolization before the open procedure. One endograft was removed and replaced by a bifurcated Dacron graft because of distal dislocation in one patient. All patients recovered, and no deaths were recorded postoperatively. No patients had an eventful postoperative course or any subsequent graft-related complications during follow-up.

CONCLUSIONS

Open surgical repair involving sacotomy and suturing of the feeding vessels appeared to have good outcomes in the treatment of patients with aneurysm sac expansion caused by type II endoleaks after EVAR. Preoperative embolization of feeding vessels can thus effectively reduce intraoperative bleeding.

Effect of differences in proximal neck angles on biomechanics of abdominal aortic aneurysm based on fluid dynamics

BACKGROUND

This study aimed to analyze the effect of proximal neck angulation on the biomechanical indices of abdominal aortic aneurysms (AAA) and to investigate its impact on the risk of AAA rupture.

METHODS

CT angiography (CTA) data of patients with AAA from January 2015 to January 2022 were collected. Patients were divided into three groups based on the angle of the proximal neck: Group A (∠β ≤ 30°), Group B (30°<∠β ≤ 60°), and Group C (∠β > 60°). Biomechanical indices related to the rupture risk of AAA were analyzed using computational fluid dynamics modeling (CFD-Post) based on the collected data.

RESULTS

Group A showed slight turbulence in the AAA lumen with a mixed laminar flow pattern. Group B had a regular low-speed eddy line characterized by cross-flow dominated by lumen blood flow and turbulence. In Group C, a few turbulent lines appeared at the proximal neck, accompanied by eddy currents in the lumen expansion area following the AAA shape. Significant differences were found in peak wall stress, shear stress, and the maximum blood flow velocity impact among the three groups. The maximum blood flow velocity at the angle of the proximal neck impact indicated the influence of the proximal neck angle on the blood flow state in the lumen.

CONCLUSION

As the angle of the proximal neck increased, it caused stronger eddy currents and turbulent blood flow due to a high-speed area near the neck. The region with the largest diameter in the abdominal aortic aneurysm was prone to the highest stress, indicating a higher risk of rupture. The corner of the proximal neck experienced the greatest shear stress, potentially leading to endothelial injury and further enlargement of the aneurysm.

Laparoscopy versus endovascular aneurysm repair for abdominal aortic aneurysm: A systematic review

Minimally invasive surgery is a useful alternative to open repair for patients with nonruptured abdominal aortic aneurysms (AAA). We aim to compare the clinical outcomes for three different minimally invasive techniques: hand-assisted laparoscopic surgery (HALS), total laparoscopic surgery (TLS), and endovascular aneurysm repair (EVAR). The electronic databases MEDLINE, Embase, Web of Science, Google Scholar, and the Cochrane Library were searched between January and March 2023. Cohort studies and randomized controlled trials (RCTs) comparing two minimally invasive techniques were eligible for inclusion. Primary outcomes were mortality (in-hospital, 30-day, or 1-year) and reintervention rates (30-day or 1-year). Length of surgery, blood loss, transfusion volume, conversion to open surgery, major complication rates, length of hospital stay, and length of intensive care unit (ICU) stay were also evaluated. Eight cohort studies and one RCT were included comparing patients undergoing HALS (n = 500), TLS (n = 263), and EVAR (n = 438) for elective AAA repair. The TLS group had the highest rate of 30-day postoperative reinterventions (p = 0.00056), the longest surgical duration (p = 0.0311), and the highest rate of conversion to open surgery (p < 0.001). TLS was also associated with the most blood loss during surgery, the highest blood transfusion volumes, and the longest length of ICU stay, although these results did not reach statistical significance. Subgroup analysis revealed superior contemporary EVAR outcomes compared to TLS. Laparoscopic surgery (LAS) and EVAR have comparable mortality rates. However, LAS, particularly TLS, is significantly less efficacious than EVAR in terms of intraoperative conversions to open surgery and 30-day reintervention rates. Further controlled trials with larger sample sizes are needed to confirm the evidence.

The role of taurine through endoplasmic reticulum in physiology and pathology

Taurine is a sulfur-containing amino acid found in many cell organelles that plays a wide range of biological roles, including bile salt production, osmoregulation, oxidative stress reduction, and neuromodulation. Taurine treatments have also been shown to ameliorate the onset and development of many diseases, including hypertension, fatty liver, neurodegenerative diseases and ischemia-reperfusion injury, by exerting antioxidant, anti-inflammatory, and antiapoptotic effects. The endoplasmic reticulum (ER) is a dynamic organelle involved in a wide range of cellular functions, including lipid metabolism, calcium storage and protein stabilization. Under stress, the disruption of the ER environment leads to the accumulation of misfolded proteins and a characteristic stress response called the unfolded protein response (UPR). The UPR protects cells from stress and helps to restore cellular homeostasis, but its activation promotes cell death under prolonged ER stress. Recent studies have shown that ER stress is closely related to the onset and development of many diseases. This article reviews the beneficial effects and related mechanisms of taurine by regulating the ER in different physiological and pathological states, with the aim of providing a reference for further research and clinical applications.

Lowest reported dose area product of 2.4 Gy∗cm2 for ultra-low-dose endovascular aortic aneurysm repair of a standard infrarenal aortic aneurysm

This is a report of successful treatment of an abdominal aortic aneurysm via standard endovascular aortic repair with an ultra-low dose (ULD) of 2.4 Gy∗cm2 using the latest imaging software in a hybrid operating room. To the best of our knowledge, no case has yet been reported achieving a successful outcome with such ULD values to date. The key factors to achieving an ULD regarding the dose area product comprise the right technology, procedural standardization, and team education and training. This case highlights the potential for reducing the radiation dose routinely for patients and staff alike, especially for operating room staff with daily radiation exposure.

The value of treatment choice and clinical prognosis for Riolan's arch in chronic superior mesenteric artery ischaemic disease

OBJECTIVE

To explore the value of treatment choice and clinical prognosis for Riolan's arch in chronic superior mesenteric artery (SMA) ischaemic disease in vascular surgery.

METHODS

The clinical data of 215 patients with SMA ischaemic disease (41 cases with Riolan's arch and 174 cases without) admitted to the Department of Vascular Surgery, Affiliated Drum Tower Hospital, Medical School of Nanjing University (China) from January 2019 to April 2023 were reviewed. Clinical characteristics, imaging findings, treatment, perioperative complications, and patient follow-up data were analysed to observe the impact of Riolan's arch on the prognosis of patients with SMA ischaemic disease.

RESULTS

There were significant differences in body mass index (Riolan's arch group: 22.82 ± 3.28 vs 24.03 ± 4.26 in non-Riolan's arch group, P = 0.049), Takayasu's arteritis (4.9% vs 0, respectively, P = 0.036), and secondary intervention (3.3% vs 1.9%, respectively, P < 0.001) between the two groups. Propensity score matching was used to exclude the effect of baseline data on patient outcomes. There were significant differences related to therapy method (conservative treatment, Riolan's arch group: 24.1% vs 39.7% in the non-Riolan's arch group; operative treatment, Riolan's arch group: 51.7% vs 20.7% in the non-Riolan's arch group, P = 0.014), as well as in-hospital time (9.79 ± 4.20 vs 6.86 ± 4.32, respectively, P = 0.011). There was no statistically significant difference in Kaplan-Meier curves between the two groups (log-rank test P = 0.476).

CONCLUSIONS

Riolan's arch plays an important compensatory role in SMA ischaemic disease, especially in chronic disease. We found significant differences in the treatment methods and length of hospital stay of Riolan's arch, which may suggest that Riolan's arch has some reference value in the choice of treatment mode.

A Five-Year Retrospective Study from a Single Center on the Location, Presentation, Diagnosis, and Management of 110 Patients with Aneurysms of the Femoral and Popliteal Arteries of the Lower Limb

Background: Peripheral aneurysms, although known about for centuries, are challenging to monitor due to their asymptomatic nature. Advanced imaging has improved detection, which is crucial for preventing emergent complications. This five-year retrospective study from a single center aimed to evaluate the location, presentation, diagnosis, and management of 110 patients with aneurysms of the femoral and popliteal arteries of the lower limb. Materials and methods: The study included 71 true aneurysms and 39 pseudoaneurysms patients treated between 2018-2023. Treatment methods were based on aneurysm size, atherosclerosis severity, and operation risk. The study assessed patient demographics, surgical details, postoperative complications, and aneurysm characteristics. Results: Acute limb ischemia was more prevalent in true aneurysms (25.4% vs. 7.7%; p = 0.02). Aneurysmectomy was performed more frequently in pseudoaneurysms (87.2% vs. 54.9%; p < 0.001), while endovascular treatment and surgical bypass were more common in true aneurysms (Endovascular: 22.5% vs. 2.6%; p = 0.01; bypass: 21.1% vs. 0%; p < 0.001). Early postoperative complications occurred in 22.7% of patients. The 12-month freedom from reoperations (73.7% vs. 87%; p = 0.07), amputations (97.7% vs. 93.8%; p = 0.2), and graft stenosis (78.7% vs. 86.87%; p = 0.06) showed no significant differences between groups. Conclusions: Lower limb aneurysms often present with non-specific symptoms, leading to late diagnosis and life-threatening complications. Both open and endovascular treatments are feasible, though more research is needed for pseudoaneurysms. Vigilant follow-up is crucial due to potential adverse events, though overall mortality and morbidity remain low.

Nationwide analysis of EVAR explantation outcomes in Korea: A comprehensive dataset study

OBJECTIVE

Endovascular aortic aneurysm repair (EVAR) is the primary treatment for abdominal aortic aneurysms, constituting 70%-80% of interventions. Despite initial benefits, long-term studies show increased mortality. Using nationwide data, this study assesses outcomes of EVAR, open aortic repair (OAR), and EVAR explantation (EE) in Korea, while exploring characteristics of late open conversion, including the rising EE incidence.

METHODS

Employing the National Health Insurance Service database, covering health-related data for nearly 50 million Koreans, the study spanned from 2002 to 2020. Patients with AAA diagnoses (I71.3 or I71.4) were categorized into OAR, EVAR, and EE groups based on procedural codes. Statistical analyses, including t-tests, Fisher's exact tests, Cox proportional hazard models, and multivariate Cox regression, assessed baseline characteristics, mortality risks, and factors within the EE group.

RESULTS

The analysis encompassed 26,195 patients, with 66.19% in the EVAR group, 31.87% in the OAR group, and 1.94% in the EE group. EVAR cases steadily increased from 2002 to 2018. Survival rates favored EVAR, followed by OAR and EE. 30-day survival was lower in EE than EVAR. Multivariate analysis for EE revealed no risk factors for 30-days survival but identified age, chronic kidney disease, high Charlson Comorbidity Index scores, and less than 6 months since EVAR as risk factors for overall mortality.

CONCLUSION

Rising EE trends with increased EVAR adoption, particularly evident in the Korean dataset, underscore inferior outcomes. This highlights the critical need for strategic initial treatment decisions and timely interventions to enhance overall results and mitigate the unfavorable EE incidence.

Evaluating growth patterns of abdominal aortic aneurysms among women

OBJECTIVE

Though initially protected from vessel dilation by estrogen, women may experience rapid abdominal aortic aneurysm (AAA) growth post-menopause. The rate of growth has been poorly defined in prior literature. Here, we describe aneurysm growth in a cohort of women found through an AAA screening program.

METHODS

Women with AAAs were retrospectively identified. Aortic imaging was reviewed, and measurements of maximum transverse and anterior-posterior diameters were completed. Growth was stratified by the type of aortic pathology (fusiform aneurysm, aortic ectasia, dissection with aneurysmal degeneration, saccular aneurysm) as well as size category (<3 cm, 3.0-3.9 cm, 4.0-4.9 cm, ≥5.0 cm) at diagnosis.

RESULTS

A cohort of 488 women was identified; 286 had multiple scans for review. The mean age of the entire cohort was 75 ± 9.9 years. Stratified by type of pathology, the mean age was 76 ± 8.9 years in patients with a fusiform AAA, 74 ± 9.8 years in ectasia, 65 ± 13.7 years in dissection, and 76 ± 5.6 years in saccular aneurysms. The maximum growth was highest in women with fusiform AAAs, followed by dissection, ectasia, and saccular pathology (9.7 mm, 7.0 mm, 3.0 mm, and 2.2 mm, respectively; P < .001). Comparing mean growth by year, the highest mean growth was in fusiform AAAs (3.6 mm vs 1.75 mm in dissection; P < .001). The Shapiro-Wilk test demonstrated that mean growth per year was non-normally distributed with a right skew. Stratified by aortic diameter at the time of diagnosis, mean growth/year increased with increasing size at diagnosis in fusiform AAAs and dissection (0.91 mm for <3 cm, 2.34 mm for 3.0-3.9 cm, 2.49 mm for 4.0-4.9 mm, and 6.16 mm for ≥5.0 cm in patients with fusiform AAAs vs 0.57 mm, 0.94 mm, 1.87 mm, and 2.66 mm, respectively, for patients with dissection). Smoking history was associated with a higher mean growth/year (2.6 mm vs 3.3 mm; P < .001). Conversely, patients with a family history of AAA had a lower mean growth/year (3.2 mm vs 1.5 mm; P < .001).

CONCLUSIONS

The rate of aneurysm growth in women varies based on pathology and aneurysm size, and women experience rapid aneurysm growth at sizes greater than 4.5 cm. Current screening guidelines are inadequate, and our results demonstrate that the rate of growth of fusiform aneurysms in women is faster than in men at a smaller size and may warrant more frequent surveillance than current Society for Vascular Surgery recommendations to prevent risk of increased morbidity.

Cancer Incidence After Diagnosis of Abdominal Aortic Aneurysm-Brief Report

BACKGROUND

Epidemiological and mechanistic data support a potential causal link between cardiovascular disease (CVD) and cancer. Abdominal aortic aneurysms (AAAs) represent a common form of CVD with at least partially distinct genetic and biologic pathogenesis from other forms of CVD. The risk of cancer and how this risk differs compared with other forms of CVD, is unknown among AAA patients. We conducted a retrospective cohort study using the IBM MarketScan Research Database to test whether individuals with AAA have a higher cancer risk independent of traditional shared risk factors.

METHODS

All individuals ≥18 years of age with ≥36 months of continuous coverage between 2008 and 2020 were enrolled. Those with potential Mendelian etiologies of AAA, aortic aneurysm with nonspecific anatomic location, or a cancer diagnosis before the start of follow-up were excluded. A subgroup analysis was performed of individuals having the Health Risk Assessment records including tobacco use and body mass index. The following groups of individuals were compared: (1) with AAA, (2) with non-AAA CVD, and (3) without any CVD.

RESULTS

The propensity score-matched cohort included 58 993 individuals with AAA, 117 986 with non-AAA CVD, and 58 993 without CVD. The 5-year cumulative incidence of cancer was 13.1% (12.8%-13.5%) in participants with AAA, 10.1% (9.9%-10.3%) in participants with non-AAA CVD, and 9.6% (9.3%-9.9%) in participants without CVD. Multivariable-adjusted Cox proportional hazards regression models found that patients with AAA exhibited a higher cancer risk than either those with non-AAA CVD (hazard ratio, 1.28 [95% CI, 1.23-1.32]; P<0.001) or those without CVD (hazard ratio, 1.32 [95% CI, 1.26-1.38]; P<0.001). Results remained consistent after excluding common smoking-related cancers and when adjusting for tobacco use and body mass index.

CONCLUSIONS

Patients with AAA may have a unique risk of cancer requiring further mechanistic study and investigation of the role of enhanced cancer screening.

Deciphering Abdominal Aortic Diseases Through T-Cell Clonal Repertoire of Perivascular Adipose Tissue

BACKGROUND

Recent studies suggest that immune-mediated inflammation of perivascular adipose tissue of abdominal aortic aneurysms (AAAs) contributes to disease development and progression. Whether the perivascular adipose tissue of AAA is characterized by a specific adaptive immune signature remains unknown.

METHODS AND RESULTS

To investigate this hypothesis, we sequenced the T-cell receptor β-chain in the perivascular adipose tissue of patients with AAA and compared it with patients with aortic occlusive disease, who share the former anatomical site of the lesion and risk factors but differ in pathogenic mechanisms. Our results demonstrate that patients with AAA have a lower repertoire diversity than those with aortic occlusive disease and significant differences in variable/joining gene segment usage. Furthermore, we identified a set of 7 public T-cell receptor β-chain clonotypes that distinguished AAA and aortic occlusive disease with very high accuracy. We also found that the T-cell receptor β-chain repertoire differentially characterizes small and large AAAs (aortic diameter<55 mm and ≥55 mm, respectively).

CONCLUSIONS

This work supports the hypothesis that T cell-mediated immunity is fundamental in AAA pathogenesis and opens up new clinical perspectives.

Predictors of overall mortality after endovascular abdominal aortic repair - A single centre study

OBJECTIVES

A current and ongoing challenge is to reduce patient mortality after endovascular abdominal aortic repair (EVAR). This study aimed to assess the predictors of all-cause mortality after EVAR.

METHODS

Data regarding the demographic characteristics, comorbidities, laboratory values, selected anatomical factors, post-EVAR treatment, surveillance and complications of patients who underwent elective EVAR for non-ruptured abdominal aortic aneurysm (AAA) between January 2010 and January 2021 were evaluated. Mortality was assessed until 10 October 2023. Multivariate analyses were performed after adjusting for age, hypertension, diabetes mellitus, dyslipidaemia, sex, smoking, number of lumbar arteries, patency of inferior mesenteric artery (IMA), IMA diameter and reinterventions.

RESULTS

This study included 196 patients (183 men and 13 women) with a mean age of 72.4 ± 7.67 years. The overall mortality rate during a mean follow-up period of 5.75 ± 3.1 years was 50.0% (N = 98). The 2-, 5- and 10-year mortality rates were 9.7%, 32.0% and 66.6%, respectively. The mortality rates decreased by 59% in patients with reinterventions (hazard ratio [HR]: 0.41; 95% confidence interval [CI]: 0.23-0.73; p = .002) and by 59% in patients treated with angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs) (HR: 0.41; 95% CI: 0.26-0.66; p < .001). Chronic anticoagulation was associated with 2.09-fold higher mortality (HR: 2.09; 95% CI: 1.19-3.67; p = .010), and coronary artery disease (CAD) was associated with 1.74-fold higher mortality (HR: 1.74; 95% CI: 1.09-2.78; p = .021). Pre-EVAR AAA diameter and 1-year post-EVAR sac diameter were positively associated with mortality (HR: 1.05; 95% CI: 1.03-1.08; p < .001, and HR: 1.05; 95% CI: 1.03-1.07; p < .001, respectively), that is, an increase of pre-EVAR and/or 1-year post-EVAR AAA diameter by 1 mm was associated with a 5% higher risk of all-cause mortality.

CONCLUSIONS

Reinterventions and treatment with ACE inhibitors or ARBs may be associated with decreased post-EVAR mortality. A greater pre-EVAR, a post-EVAR AAA diameter, CAD and chronic anticoagulation were associated with higher all-cause mortality post-EVAR.

CT analysis of aortic calcifications to predict abdominal aortic aneurysm rupture

BACKGROUND

Abdominal aortic aneurysm (AAA) rupture prediction based on sex and diameter could be improved. The goal was to assess whether aortic calcification distribution could better predict AAA rupture through machine learning and LASSO regression.

METHODOLOGY

In this retrospective study, 80 patients treated for a ruptured AAA between January 2001 and August 2018 were matched with 80 non-ruptured patients based on maximal AAA diameter, age, and sex. Calcification volume and dispersion, morphologic, and clinical variables were compared between both groups using a univariable analysis with p = 0.05 and multivariable analysis through machine learning and LASSO regression. We used AUC for machine learning and odds ratios for regression to measure performance.

RESULTS

Mean age of patients was 74.0 ± 8.4 years and 89% were men. AAA diameters were equivalent in both groups (80.9 ± 17.5 vs 79.0 ± 17.3 mm, p = 0.505). Ruptured aneurysms contained a smaller number of calcification aggregates (18.0 ± 17.9 vs 25.6 ± 18.9, p = 0.010) and were less likely to have a proximal neck (45.0% vs 76.3%, p < 0.001). In the machine learning analysis, 5 variables were associated to AAA rupture: proximal neck, antiplatelet use, calcification number, Euclidian distance between calcifications, and standard deviation of the Euclidian distance. A follow-up LASSO regression was concomitant with the findings of the machine learning analysis regarding calcification dispersion but discordant on calcification number.

CONCLUSION

There might be more to AAA calcifications that what is known in the present literature. We need larger prospective studies to investigate if indeed, calcification dispersion affects rupture risk.

CLINICAL RELEVANCE STATEMENT

Ruptured aneurysms are possibly more likely to have their calcification volume concentrated in a smaller geographical area.

KEY POINTS

• Abdominal aortic aneurysm (AAA) rupture prediction based on sex and diameter could be improved. • For a given calcification volume, AAAs with well-distributed calcification clusters could be less likely to rupture. • A machine learning model including AAA calcifications better predicts rupture compared to a model based solely on maximal diameter and sex alone, although it might be prone to overfitting.

The association between sarcopenia and adverse outcomes after complex endovascular aortic repair

BACKGROUND

Sarcopenia is identified as a predictive factor for adverse outcomes after complex endovascular aortic repair (complex EVAR). Consensus on preferred parameters for sarcopenia is not yet reached. The current study compares three CT-assessed parameters on their association with adverse outcomes after complex EVAR.

METHODS

This was a single-center retrospective cohort study. Psoas Muscle Index (PMI), Skeletal Muscle Index (SMI), and lean psoas muscle area (LPMA) were examined by CT-segmentation. PMI, SMI, and LPMA were analyzed as continuous variables. In addition, cut-off values from previous research were used to diagnose patients as sarcopenic or non-sarcopenic. Outcomes were: all-cause mortality, major adverse events (MAE), length of hospital stay, and non-home discharge. A sub-analysis was made for severe sarcopenia; sarcopenia combined with low physical performance (gait speed, Time Up and Go test, Metabolic Equivalent of Task-score).

RESULTS

We included 101 patients. A higher PMI (HR=0.590, CI: 0.374-0.930, P=0.023), SMI (HR=0.453, CI: 0.267-0.768, P=0.003), and LPMA (HR=0.559, CI: 0.333-0.944, P=0.029) were associated with a lower risk of mortality. Sarcopenia based on cut-off values for PMI and LPMA was not significantly associated with survival. Sarcopenia based on SMI did present a higher mortality risk (P=0.017). A sub-analysis showed that severely sarcopenic patients were at even higher risk of mortality (P=0.036). None of the parameters were significantly associated with the other outcomes.

CONCLUSIONS

SMI had a slightly stronger association with mortality compared to PMI and LPMA. High-risk patients were selected by adding physical performance scores. Future research could focus on complex EVAR-specific PMI and LPMA cut-off values.

Laser assisted trans-endograft coil embolization of a type II endoleak

A type II endoleak after endovascular aneurysm repair can be challenging to stop. Numerous methods have been described, including trans-arterial, trans-lumbar, trans-caval, trans-endograft, peri-endograft, and open and laparoscopic surgical techniques. We present our experience with a laser-assisted trans-endograft approach, including technical variations of previous descriptions that might improve efficacy. In select cases, the laser-assisted trans-endograft approach might provide the most direct method of accessing and occluding the vessels feeding type II endoleaks.

ACR Appropriateness Criteria® Screening for Abdominal Aortic Aneurysm

Abdominal aortic aneurysm (AAA) is a significant vascular disease found in 4% to 8% of the screening population. If ruptured, its mortality rate is between 75% and 90%, and it accounts for up to 5% of sudden deaths in the United States. Therefore, screening of AAA while asymptomatic has been a crucial portion of preventive health care worldwide. Ultrasound of the abdominal aorta is the primary imaging modality for screening of AAA recommended for asymptomatic adults regardless of their family history or smoking history. Alternatively, duplex ultrasound and CT abdomen and pelvis without contrast may be appropriate for screening. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Type III Endoleak Incidence and Outcomes in Endovascular Aortic Repair: Comparison of Anatomical and Proximal Fixation Devices

PURPOSE

To evaluate the influence of endograft fixation type on the incidence, treatment, and outcomes of type III endoleaks (TIIIELs).

MATERIALS AND METHODS

Abdominal aortic aneurysms (AAAs) treated with bifurcated endografts between 1994 and 2020 were prospectively collected and reviewed. The endograft included were classified as "Anatomical Fixation" (AF) (Powerlink [Endologix] and AFX [Endologix]) or "Proximal Fixation" (PF). The primary outcome was the incidence of TIIIEL over time, stratified by fixation type. Secondary outcomes included between-group comparisons of baseline characteristics, intraoperative details during TIIIEL correction, and survival analysis after TIIIEL diagnosis.

RESULTS

A total of 2065 endovascular aneurysm repairs were performed: 872 (42.2%) with AF and 1193 (57.8%) with PF devices. The estimated incidence of TIIIEL at 1, 5, and 10 years was 0.4%, 4.2%, and 7.3%, and 0.5%, 3.2%, and 4.6% for AF and PF, respectively (p=0.157), and fixation type was not associated with TIIIEL development in the competing risk regression model (p=0.101). The cumulative overall survival rate in patients diagnosed with TIIIEL did not differ significantly between the groups (p=0.077). The rate of recurrent TIIIELs was significantly lower in the AF group (7.1% vs 22.7%; p=0.044); however, no significant difference was found in secondary reintervention between the two groups (11.9% vs 27.3%, p=0.074). Patients with angulated and calcified aortic neck (SHR 3.4, 95% CI 1.2-9.6, p=0.022) and larger aneurysms (SHR 1.2; 95% CI 1.1-1.3; p<0.001) had a higher risk of TIIIEL. Likewise, the use of three or more endograft components increased the risk of TIIIEL by 3.1 times (SHR 3.1; 95% CI 1.7-5.4; p<0.001).

CONCLUSIONS

The occurrence of TIIIELs was not affected by the type of endograft fixation. For larger abdominal aortic aneurysms (AAAs) and aneurysms with angulated and calcified aortic necks, there is a higher likelihood of developing TIIIELs during follow-up, regardless of the endograft type used.

CLINICAL IMPACT

The type of fixation does not influence the incidence of TIII ELs. EVAR in larger AAAs and aneurysms with angulated and calcified aortic necks have a higher risk of developing TIII EL. Moreover, the risk of TIII EL is considerably increased by the use of three or more modular components.

Editor's Choice - External Validation of a Prognostic Model for Survival of Patients With Abdominal Aortic Aneurysms Treated by Endovascular Aneurysm Repair

OBJECTIVE

Current guidelines recommend diameter monitoring of small and asymptomatic abdominal aortic aneurysms (AAAs) due to the low risk of rupture. Elective AAA repair is recommended for diameters ≥ 5.5 cm in men and ≥ 5.0 cm in women. However, data supporting the efficacy of elective treatment for all patients above these thresholds are diverging. For a subgroup of patients, life expectancy might be very short, and elective AAA repair at the current threshold may not be justified. This study aimed to externally validate a predictive model for survival of patients with an asymptomatic AAA treated by endovascular aneurysm repair (EVAR).

METHODS

This was a multicentre international retrospective observational cohort study. Data were collected from four European aortic centres treating patients between 2001 and 2021. The initial model included age, estimated glomerular filtration rate (eGFR), and chronic obstructive pulmonary disease (COPD) as independent predictors for survival. Model performance was measured by discrimination and calibration.

RESULTS

The validation cohort included 1 500 patients with a median follow up of 65 months, during which 54.6% of the patients died. The external validation showed slightly decreased discrimination ability and signs of overfitting in model calibration. However, a high risk subgroup of patients with impaired survival rates was identified: octogenarians with eGFR < 60 OR COPD, septuagenarians with eGFR < 30, and septuagenarians with eGFR < 60 and COPD having survival rates of only 55.2% and 15.5% at five and 10 years, respectively.

CONCLUSION

EVAR is a valuable treatment option for AAA, especially for patients unsuitable for open repair. Nonetheless, not all these patients will benefit from EVAR, and an individualised treatment recommendation should include considerations on life expectancy. This study provides a risk stratification to identify patients who may not benefit from EVAR using the present diameter thresholds.

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.

Controlling the nutritional status score: a new tool for predicting postoperative mortality in patients with infrarenal abdominal aortic aneurysm treated with endovascular aneurysm repair

Background

AAA is a fatal condition that commonly occurs during vascular surgery. Nutritional status exerts a significant influence on the prognosis of various pathological conditions Scores from the CONUT screening tool have been shown to predict outcomes of certain malignancies and chronic diseases. However, the ramifications of nutritional status on AAA patients undergoing EVAR have not been elucidated in prior studies. In this study, we aimed to elucidate the correlation between CONUT scores and postoperative prognostic outcomes in patients with AAA undergoing EVAR.

Methods

This was a retrospective review of 177 AAA patients treated with EVAR from June 2018 to November 2019 in a single center. Patient characteristics, CONUT scores, and postoperative status were collected. These patients were stratified into groups A and B according to CONUT scores. Subsequently, a comparative analysis of the baseline characteristics between the two cohorts was conducted. Cox proportional hazards and logistic regression analyses were employed to identify the autonomous predictors of mid-term mortality and complications, respectively.

Results

Compared with group A, patients in group B had higher midterm mortality (p < 0.001). Univariate analysis showed that CONUT scores; respiratory diseases; stent types; preoperative Hb, CRP, PT, and Fb levels were risk factors for death. Multivariate analysis confirmed that CONUT score [HR, 1.276; 95% CI, 1.029-1.584; p = 0.027] was an independent risk factor for mortality. Logistic regression analysis showed that prior arterial disease, smoking, and D-dimer levels were risk factors, although multivariate analysis showed smoking (OR, 3.492; 95% CI, 1.426-8.553; p = 0.006) was an independent risk factor. Kaplan-Meier curves showed that patients in group B had shorter mid-term survival than those in group A (log-rank p < 0.001).

Conclusion

Malnutrition was strongly associated with mid-term mortality in patients with infrarenal AAA treated with EVAR.

Endurant Stent Graft for Treatment of Abdominal Aortic Aneurysm Inside and Outside of the Instructions for Use for the Proximal Neck: A 14-Year, Single-Center Experience

Aim: To assess the medium and long-term performance of the Endurant stent graft in a cohort of consecutive patients treated with this device for an abdominal aortic aneurysm (AAA) both inside and outside of the instructions for use (IFU) and to find factors influencing the outcomes. Methods: Our observational, retrospective, single-center study included all patients who consecutively underwent endovascular aneurysm repair with the Endurant stent graft from February 2009 to January 2023. Patients with an AAA to treat according to current guidelines were included. Patients were divided into two groups: Group 1 inside of the IFUs and Group 2 outside of the IFUs for the proximal aortic neck. Patients were followed up after the procedure with computed angiography tomography, ultrasound examination, and interviews. Aneurysm-related mortality, procedure-related reinterventions, and type IA and III endoleaks were considered primary endpoints. Secondary endpoints included aneurysmal sac variations and graft thrombosis. Results: A total of 795 patients were included, 650 in Group 1 and 145 in Group 2; 732 were males, and the mean age was 74 ± 8. Anamnestic baseline did not differ between the two groups. Neck length, width, and angulation were different between the two groups (all p < 0.001). A total of 40 patients had a ruptured AAA, while 56 were symptomatic. At a mean follow-up of 43 ± 39 months, aneurysm-related mortality was less than 1%, and 82 endoleak (10.5%) were observed. Overall endoleak rate and type 1A endoleak, as well as procedure-related reintervention, were significantly more frequent in Group 2. Sac regression of at least 5 mm was observed in 65.9% of cases. AAAs larger than 60.5 mm carried a higher risk of endoleak (HR: 1.025; 95% CI: 1.013-1.37; p < 0.001) and proximal necks shorter than 13.5 mm carried a higher type 1A risk (HR: 0.890; 95% CI: 0.836-0.948; p < 0.001). Patients without chronic obstructive pulmonary disease and taking lipid-lowering drugs had an overall more consistent sac-shrinking rate. Conclusions: The Endurant stent graft proves safe and reliable. Out-of-IFU treatment has poorer medium and long-term outcomes. Some conditions influence medium and long-term reintervention risk and sac behavior. Patients with bigger aneurysms, proximal necks shorter than 13.5 mm, and chronic obstructive pulmonary disease should be more carefully evaluated during follow-up. Consistent follow-up is in keeping low aneurysm-related mortality. Personalized risk profiles and peri and postoperative management strategies are needed.

Laparoscopic Ligation of the Inferior Mesenteric Artery: A Systematic Review of an Emerging Trend for Addressing Type II Endoleak Following Endovascular Aortic Aneurysm Repair

Background/Objectives: this systematic review aims to explore the efficacy and safety of the laparoscopic ligation of the inferior mesenteric artery (IMA) as an emerging trend for addressing a type II endoleak following endovascular aortic aneurysm repair (EVAR). Methods: A comprehensive literature search was conducted across several databases including Medline, Scopus, and the Cochrane Central Register of Controlled Trials, adhering to the PRISMA guidelines. The search focused on articles reporting on the laparoscopic ligation of the IMA for the treatment of a type II endoleak post-EVAR. Data were extracted regarding study characteristics, patient demographics, technical success rates, postoperative outcomes, and follow-up results. Results: Our analysis included ten case studies and two retrospective cohort studies, comprising a total of 26 patients who underwent a laparoscopic ligation of the IMA between 2000 and 2023. The mean age of the cohort was 72.3 years, with a male predominance (92.3%). The mean AAA diameter at the time of intervention was 69.7 mm. The technique demonstrated a high technical success rate of 92.3%, with a mean procedure time of 118.4 min and minimal blood loss. The average follow-up duration was 19.9 months, with 73% of patients experiencing regression of the aneurysmal sac, and no reports of an IMA-related type II endoleak during the follow-up period. Conclusions: The laparoscopic ligation of the IMA for a type II endoleak following EVAR presents a promising, minimally invasive alternative with high technical success rates and favorable postoperative outcomes. Despite its potential advantages, including reduced contrast agent use and radiation exposure, its application remains limited to specialized centers. The findings suggest the need for further research in larger prospective studies to validate the effectiveness of this procedure and potentially broaden its clinical adoption.

Importance of sac regression after EVAR and the role of EndoAnchors

The initial success and widespread adoption of endovascular aneurysm repair (EVAR) for the treatment of abdominal aortic aneurysms have been tempered by numerous reports of secondary interventions and increased long-term mortality compared with open repair. Over the past decade, several studies on postoperative sac dynamics after EVAR have suggested that the presence of sac regression is a benign feature with a favorable prognosis. Conversely, increasing sacs and even stable sacs can be indicators of more unstable sac behavior with worse outcomes in the long-term. Endoleaks were initially perceived as the main drivers of sac behavior. However, the observation that sac regression can occur in the presence of endoleaks, and vice versa - increasing sacs without evidence of endoleak - on imaging studies, suggests the involvement of other contributing factors. These factors can be divided into anatomical factors, patient characteristics, sac thrombus composition, and device-related factors. The shift of interest away from especially type 2 endoleaks is further supported by promising results with the use of EndoAnchors regarding postoperative sac behavior. This review provides an overview of the existing literature on the implications and known risk factors of post-EVAR sac behavior, describes the accurate measurement of sac behavior, and discusses the use of EndoAnchors to promote sac regression.

Narrative Review of Risk Assessment of Abdominal Aortic Aneurysm Rupture Based on Biomechanics-Related Morphology

CLINICAL IMPACT

Studies have shown that the biomechanical indicators based on multi-scale models are more effective in accurately assessing the rupture risk of AAA. To meet the need for clinical monitoring and rapid decision making, the typical morphological parameters associated with AAA rupture and their relationships with the mechanical environment have been summarized, which provide a reference for clinical preoperative risk assessment of AAA.

Increasing abdominal aortic aneurysm curvature visibility using 3D dual probe bistatic ultrasound imaging combined with probe translation

High frame rate ultrasound (US) imaging techniques in 3D are promising tools for capturing abdominal aortic aneurysms (AAAs) over time, however, with the limited number of channel-to-element connections current footprints are small, which limits the field of view. Moreover, the maximal steering angle of the ultrasound beams in transmit and the maximal receptance angle in receive are insufficient for capturing the curvy shape of the AAA. Therefore, an approach is needed towards large arrays. In this study, high frame rate bistatic 3D US data (17 Hz) were acquired with two synchronized matrix arrays positioned at different locations (multi-aperture imaging) using a translation stage to simulate what a larger array with limited channel-to-element connections can potentially achieve. Acquisitions were performed along an AAA shaped phantom with different probe tilting angles (0 up to ± 30°). The performance of different multi-aperture configurations was quantified using the generalized contrast-to-noise ratio of the wall and lumen (gCNR). Furthermore, a parametric model of the multi-aperture system was used to estimate in which AAA wall regions the contrast is expected to be high. This was evaluated for AAAs with increasing diameters and curvature. With an eight-aperture 0° probe angle configuration a 69 % increase in field of view was measured in the longitudinal direction compared to the field of view of a single aperture configuration. When increasing the number of apertures from two to eight, the gCNR improved for the upper wall and lower wall by 35 % and 13 % (monostatic) and by 36 % and 13 % (bistatic). Contrast improvements up to 22 % (upper wall) and 12 % (lower wall) are achieved with tilted probe configurations compared to non-tilted configurations. Moreover, with bistatic imaging with tilted probe configurations gCNR improvements up to 4 % (upper wall) and 7 % (lower wall) are achieved compared to monostatic imaging. Furthermore, imaging with a larger inter-probe distance improved the gCNR for a ± 15° probe angle configuration. The gCNR has an expected pattern over time, where the contrast is lower when there is more wall motion (systole) and higher when motion is reduced (diastole). Furthermore, a higher frame rate (45 Hz) yields a lower gCNR, because fewer compound angles are used. The results of the parametric model suggest that a flat array is suitable for imaging AAA shapes with limited curvature, but that it is not suitable for imaging larger AAA shapes with more curvature. According to the model, tilted multi-aperture configurations combined with bistatic imaging can achieve a larger region with high contrast compared to non-tilted configurations. The findings of the model are in agreement with experimental findings. To conclude, this study demonstrates the vast improvements in field of view and AAA wall visibility that a large, sparsely populated 3D array can potentially achieve when imaging AAAs compared to single or dual aperture imaging. In the future, larger arrays, less thermal noise, more steering, and more channel-to-element connections combined with carefully chosen orientations of (sub-) apertures will likely advance 3D imaging of AAAs.

Novel Strategies for the Hostile Iliac Artery during Endovascular Aortic Aneurysm Repair

Successful endovascular aneurysm repair can be achieved with favorable aortic and iliac arterial anatomies. However, patients with challenging iliac anatomy, such as stenotic, calcified, tortuous arteries, or concomitant iliac artery aneurysms, are commonly encountered. Such a hostile iliac anatomy increases the risk of intraprocedural complications and worsens long-term outcomes. This review addresses various technical options for treating patients with a hostile iliac anatomy, including innovative endovascular solutions, physician-modified endografts, and hybrid procedures. These considerations demonstrate the wide scope of therapies that may be offered to patients with an unfavorable iliac anatomy.

Ultrasound Surveillance is Feasible After Endovascular Aneurysm Repair

BACKGROUND

Surveillance after endovascular aneurysm repair (EVAR) is traditionally done with computed tomography angiography (CTA) scans that exposes patient to radiation, nephrotoxic contrast media, and potentially increased risk for cancer. Ultrasound (US) is less labor intensive and expensive and might thus provide a good alternative for CTA surveillance. The aim of this study was to evaluate in real-life patient cohorts whether US is able to detect post-EVAR aneurysm-related complications similarly to CTA.

METHODS

This retrospective study compared the outcome of consecutive patients who underwent EVAR for intact abdominal aortic aneurysm and were surveilled solely by CTA (CTA-only cohort, n = 168) in 2000-2010 or by combined CTA and US (CTA/US cohort, n = 300) in 2011-2016, as a standard surveillance protocol in the department of vascular surgery, Helsinki University Hospital. The CTA-only patients were imaged at 1, 3, and 12 months and annually thereafter. The CTA/US patients were imaged with CTA at 3 and 12 months, US at 6 months and annually thereafter. If there were suspicion of >5 mm aneurysm growth, CTA scan was performed. The patients were reviewed for imaging data, reinterventions, aneurysm ruptures, and death until December 2018. The 2 groups were compared for secondary rupture, aneurysm-related and cancer-related death, reintervention related to abdominal aortic aneurysm, and maximum aneurysm diameter increase ≥5 mm. The mean follow-up in the CTA-only cohort was 67 months and in CTA/US cohort 43 months.

RESULTS

The 2 cohorts were alike for basic characteristics and for the mean aneurysm diameter. The total number of CT scans for detecting aneurysm was 84.1/100 patient years in the CTA-only cohort compared to 74.5/100 patient years for US/CTA cohort. Forty percent of patients under combined CTA/US surveillance received 1 or more additional CTA scans. The 2 cohorts did not differ for 1-year, 5-year and 8-year freedom from aneurysm related death, secondary sac rupture, nor the incidence of rupture preventing interventions.

CONCLUSIONS

Based on the follow-up data of this real-life cohort of 468 patients, combined surveillance with US and additional CTA either per protocol or due to suspicion of aneurysm-related complications had comparable outcome with sole CTA-surveillance. Thus, US can be considered a reasonable alternative for the CTA. However, our study showed also that the need of additional CTAs due to suspicion of endoleak or aneurysm nonrelated reasons is substantial.

CIRSE Standards of Practice on Management of Endoleaks Following Endovascular Aneurysm Repair

BACKGROUND

Endoleaks represent the most common complication after EVAR. Some types are associated with ongoing risk of aneurysm rupture and necessitate long-term surveillance and secondary interventions.

PURPOSE

This document, as with all CIRSE Standards of Practice documents, will recommend a reasonable approach to best practices of managing endoleaks. This will include imaging diagnosis, surveillance, indications for intervention, endovascular treatments and their outcomes. Our purpose is to provide recommendations based on up-to-date evidence, updating the guidelines previously published on this topic in 2013.

METHODS

The writing group was established by the CIRSE Standards of Practice Committee and consisted of clinicians with internationally recognised expertise in endoleak management. The writing group reviewed the existing literature performing a pragmatic evidence search using PubMed to select publications in English and relating to human subjects up to 2023. The final recommendations were formulated through consensus.

RESULTS

Endoleaks may compromise durability of the aortic repair, and long-term imaging surveillance is necessary for early detection and correct classification to guide potential re-intervention. The majority of endoleaks that require treatment can be managed using endovascular techniques. This Standards of Practice document provides up-to-date recommendations for the safe management of endoleaks.

Initial two-day blood pressure management after endovascular aneurysm repair improves midterm outcomes by reducing the incidence of early type II endoleak

OBJECTIVE

The aim of this study was to evaluate midterm outcomes of our novel strategy of postoperative initial 2-day blood pressure management (BPM) after endovascular aneurysm repair (EVAR) for the prevention of subsequent type II endoleak (T2EL) in a single-center series.

METHODS

Between 2008 and 2014, 137 patients who underwent EVAR for abdominal aortic aneurysm (AAA) were reviewed. Starting from 2013, the mean blood pressure was maintained between 75 and 90 mmHg for the initial 24 hours after EVAR followed by systolic pressure controlled below 120 mmHg during the next 24 hours in the treatment group (n = 76). The incidence of T2EL detected at 7 days, reintervention, and AAA sac diameter up to 5 years after EVAR were compared with those of the control group comprising of 60 consecutive patients who underwent standard EVAR without BPM prior to 2013.

RESULTS

Between the treatment group and the control group, significant differences were achieved in the incidence of T2EL at 7 days (19.7% vs 40.0%; P = .009), a mean decrease of AAA sac diameter at 1-year (-5.1 ± 4.9 vs -2.2 ± 6.7 mm; P = .013) and 2-year (-5.4 ± 7.7 vs -1.7 ± 10.8 mm; P = .045). In addition, there was a significant decrease in the incidence of T2EL detected at 7 days with the use of the Gore Excluder with 22.7% in the treatment group vs 80.0% in the control group (P < .001), which resulted in a significant decrease in the aneurysm sac diameter up to 4 years after EVAR. Survival rate without AAA sac enlargement at 5 years after EVAR (83.0% vs 70.0%; P = .021) in the treatment group was significantly higher than that of the control group, whereas no significant differences were observed in the freedom rates of reintervention, T2EL-related reintervention, and all-cause mortality between the groups.

CONCLUSIONS

Postoperative initial 2-day BPM had a preventive effect on AAA sac enlargement until midterm periods, by reducing the incidence of T2EL at 7 days after EVAR. The usage of Gore Excluder under BPM was especially associated with sustained positive effects until the midterm follow-up.

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.

Air pollutants, genetic susceptibility, and abdominal aortic aneurysm risk: a prospective study

BACKGROUND AND AIMS

Air pollutants are important contributors to cardiovascular diseases, but associations between long-term exposure to air pollutants and the risk of abdominal aortic aneurysm (AAA) are still unknown.

METHODS

This study was conducted using a sample of 449 463 participants from the UK Biobank. Hazard ratios and 95% confidence intervals for the risk of AAA incidence associated with long-term exposure to air pollutants were estimated using the Cox proportional hazards model with time-varying exposure measurements. Additionally, the cumulative incidence of AAA was calculated by using the Fine and Grey sub-distribution hazards regression model. Furthermore, this study investigated the combined effects and interactions between air pollutants exposure and genetic predisposition in relation to the risk of AAA onset.

RESULTS

Long-term exposure to particulate matter with an aerodynamic diameter <2.5 µm [PM2.5, 1.21 (1.16, 1.27)], particulate matter with an aerodynamic diameter <10 µm [PM10, 1.21 (1.16, 1.27)], nitrogen dioxide [NO2, 1.16 (1.11, 1.22)], and nitrogen oxides [NOx, 1.10 (1.05, 1.15)] was found to be associated with an elevated risk of AAA onset. The detrimental effects of air pollutants persisted even in participants with low-level exposure. For the joint associations, participants with both high levels of air pollutants exposure and high genetic risk had a higher risk of developing AAA compared with those with low concentrations of pollutants exposure and low genetic risk. The respective risk estimates for AAA incidence were 3.18 (2.46, 4.12) for PM2.5, 3.09 (2.39, 4.00) for PM10, 2.41 (1.86, 3.13) for NO2, and 2.01 (1.55, 2.61) for NOx.

CONCLUSIONS

In this study, long-term air pollutants exposure was associated with an increased risk of AAA incidence.

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

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

A preoperative supervised exercise program potentially improves long-term survival after elective abdominal aortic aneurysm repair

OBJECTIVE

A preoperative supervised exercise program (SEP) improves cardiorespiratory fitness and perioperative outcomes for patients undergoing elective abdominal aortic aneurysm (AAA) repair. The aim of this study was to assess the effect of a preoperative SEP on long-term survival of these patients. A secondary aim was to consider long-term changes in cardiorespiratory fitness and quality of life.

METHODS

Patients scheduled for open or endovascular AAA repair were previously randomized to either a 6-week preoperative SEP or standard management, and a significant improvement in a composite outcome of cardiac, pulmonary, and renal complications was seen following SEP. For the current analysis, patients were followed up to 5 years post-surgery. The primary outcome for this analysis was all-cause mortality. Data were analyzed on an intention to treat (ITT) and per protocol (PP) basis, with the latter meaning that patients randomized to SEP who did not attend any sessions were excluded. The PP analysis was further interrogated using a complier average causal effect (CACE) analysis on an all or nothing scale, which adjusts for compliance. Additionally, patients who agreed to follow-up attended the research center for cardiopulmonary exercise testing and/or provided quality of life measures.

RESULTS

ITT analysis demonstrated that the primary endpoint occurred in 24 of the 124 participants at 5 years, with eight in the SEP group and 16 in the control group (P = .08). The PP analysis demonstrated a significant survival benefit associated with SEP attendance (4 vs 16 deaths; P = .01). CACE analysis confirmed a significant intervention effect (hazard ratio, 0.36; 95% confidence interval, 0.16-0.90; P = .02). There was no difference between groups for cardiorespiratory fitness measures and most quality of life measures.

CONCLUSIONS

These novel findings suggest a long-term mortality benefit for patients attending a SEP prior to elective AAA repair. The underlying mechanism remains unknown, and this merits further investigation.

Perspectives of Patients and Professionals on Patient Education in Complex Endovascular Aortic Repair

BACKGROUND

Misinterpretation of patient preferences in perioperative education can lead to an undesired treatment decision. This explorative interview study presents differences in perspectives of patients and professionals on patient education in complex endovascular aortic aneurysm management.

METHODS

Using convenience sampling, a cross-sectional interview study was performed among patients who were in various stages of the decision-making process for complex endovascular aortic repair. Five physicians were interviewed, representing the main providers of clinical information. Interviews were transcribed verbatim and analyzed inductively.

RESULTS

Twelve patients (mean age 76.6 [standard deviation: 6.4], 83% male) were interviewed. Ten (83%) felt like they had no other realistic option besides undergoing surgery, whereas all professionals (5/5) stressed the importance of delicate patient selection. Five patients out of 10 (50%) who commented on their preferred decisional role considered the professional's advice as decisive. All but 1 patient (11/12) reported that the information was easy to understand, whereas 4 out of 5 professionals (80%) doubted whether patients could fully comprehend everything. Patients experienced a lack of information on the recovery process, although professionals stated that this was addressed during consultation.

CONCLUSIONS

Several differences were found in the perspectives of patients and professionals on education in complex aortic aneurysm management. In order to optimize patient involvement in decision-making, professionals should be aware of these possible discrepancies and address them during consultation. Future research could focus on these differences in more detail by including more patients depending on their treatment and decision stages.

Danish men's experiences of cardiovascular screening and their views on preventive cardiovascular medication: A qualitative explorative nurse study

OBJECTIVES

This study explored Danish men's experience of participating in a screening program for cardiovascular disease (CVD) and their perceptions of preventive medication for CVD before and after participation in the screening program.

METHODS

An exploratory phenomenological-hermeneutical study. Fifteen men from a cardiovascular screening program for men aged 65-74 years participated. Semi-structured interviews were conducted before screening and one year later (2015-2017). The interviews were transcribed verbatim and analysed using Kvale and Brinkmann's approach to data analysis.

RESULTS

Two main themes were identified: (i) seeking confirmation and control of health: familiarity with CVD; understanding the screening program; confirmation of health; perception of preventive medication, and (ii) sense of own health and prevention: experiences with the screening program; accept or denial of diagnosis and preventive medication.

CONCLUSION

A minority of the men understood the nature of the diseases for which they were being examined. The invitation for screening and the outcome of the examinations must be communicated more skilfully. The health providers need to engage early in treatment after the screening and provide an individualised plan that addresses patients concerns and knowledge based on their needs.

Management of Coeliac and Hepatic Artery Aneurysms: An Experience of 84 Cases

OBJECTIVE

To report outcomes following open or endovascular treatment of true hepatic and coeliac artery aneurysms at a single referral centre.

METHODS

This was a retrospective cohort study of consecutive patients treated for true hepatic and coeliac artery aneurysms between May 2002 and December 2021. Outcome measures included complications, graft patency, and survival rate.

RESULTS

Overall, 84 patients were included with a median age of 63 years (interquartile range 55, 79). The majority (76%) of the patients were men. Frequent comorbidities included a history of tobacco (69%), hypertension (65%), hyperlipidaemia (32%), and diabetes (15%). Multiple synchronous aneurysms were detected in 22 patients (26%). There were 33 (39%) symptomatic aneurysms (abdominal pain without rupture [n = 18], rupture [n = 10], and sepsis [n = 5]). Seventeen patients (20%) had mycotic aetiology. Fifty patients (60%) underwent endovascular treatment with either covered stent placement (n = 29) or coil embolisation (n = 21), and 34 patients (40%) were treated with open surgery using allogenic iliac artery (n = 15), autologous saphenous vein (n = 15), GoreTex graft (n = 2), or ligation (n = 2). The complication rate was 32% in the open group and 18% in the endovascular group (p = .048). The overall 90 day post-operative mortality rate was 1.2%, five year primary patency was 90.0%, five year survival rate was 81.2%, and mean follow up was 6.9 ± 4.2 years.

CONCLUSION

Endovascular treatment is the preferred approach whenever technically possible. Despite higher post-operative morbidity, an open approach with vascular reconstruction using autologous or allogenic vascular grafts yields acceptable long term results.

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.

Early experience with bridging stent graft deployment without sheath support in branched and fenestrated endovascular aortic repair

OBJECTIVE

To assess the early experience with modified version of simplified bare-wire target vessel (SMART) technique, implying delivery of bridging stent grafts without historically established sheath support, and to compare its outcome to standard endovascular aortic repair procedures with fenestrated/branched devices.

METHODS

A retrospective analysis of 102 consecutive patients treated with fenestrated/branched devices from January 2020 to December 2022 was undertaken. The study population was divided into three groups-a sheath group (SG), SMART group, and nonsheath group (NSG). Primary end points were radiation exposure (dose-area product), fluoroscopy time, dose of contrast agent, operation time, and incidence of intraoperative target vessel (TV) complications and additional procedures. Freedom from secondary TV related reinterventions at the three follow-up phases were defined as secondary end points.

RESULTS

A total of 183 TVs (38.8% visceral arteries [VA]; 56.3% renal arteries [RA]) in the SG, 36 TVs (44.4% VA, 55.6% RA) in the SMART group, and 168 TVs (47.6% VA; 50% RA) in the NSG were accessed. The mean number of fenestrations and bridging stent grafts was equally distributed in all three groups. The SMART group only included cases treated with fenestrated devices. The dose-area product was significantly lower in the SMART (median, 203 Gy × cm2; interquartile range [IQR], 179-365 Gy × cm2) and NSG (median, 340 Gy × cm2; IQR, 220-651 Gy × cm2) groups vs the SG (median, 464 Gy × cm2; IQR, 267-871 Gy × cm2; P = .007). Operation time was also significantly lower in the NSG (median, 265 minutes; IQR, 221-337 minutes) and SMART (median, 292 minutes; IQR, 234-351 minutes) groups vs the SG (median, 326 minutes; IQR, 277-375 minutes; P = .004), respectively. Intraoperative TV-related complications were most frequently observed in the SG (9/183 TVs; P = .008).

CONCLUSIONS

This study reports the outcomes of three currently available TV stenting approaches. Previously reported SMART technique, and its modified version (NSG) proved to be a safe alternative to historically established TV stenting technique with sheath support (SG).

Safety and Efficacy of Endovascular Aortic Repair for Abdominal Aortic Aneurysms with a Hostile Neck Anatomy

OBJECTIVE

This study aimed to investigate the safety and efficacy of endovascular aortic repair (EVAR) for the treatment of an abdominal aortic aneurysm (AAA) with a hostile neck anatomy (HNA).

METHODS

From January 1, 2015 to December 31, 2019, a total of 259 patients diagnosed with an AAA who underwent EVAR were recruited into this study. Based on the morphological characteristics of the proximal neck anatomy, the patients were divided into the HNA group and the friendly neck anatomy (FNA) group. The patients were followed up for up to 4 years.

RESULTS

The average follow-up time was 1056.1±535.5 days. Type I endoleak occurred in 4 patients in the HNA group, and 2 patients in the FNA group. Neither death nor intraoperative switch to open repair occurred in either group. The time of the operation was significantly longer in the HNA group (FNA vs. HNA, 99.2±51.1 min vs. 117.5±63.8 min, P=0.011). There were no significant differences in short-term clinical success rate (P=0.228) or midterm clinical success rate (P=0.889) between the two groups. The overall mortality rate was 10.4%, and Kaplan-Meier survival analysis indicated that the two groups had similar cumulative survival rates at the end of the follow-up period (P=0.889).

CONCLUSION

EVAR was feasible and safe in patients with an AAA with a proximal HNA. The early and midterm results were promising; however, further studies are needed to verify the long-term effectiveness of EVAR.

Iliac neck dilatation causes rupture of abdominal aortic aneurysm previously treated with endovascular aortic aneurysm repair

A 78-year-old male had undergone endovascular aortic aneurysm repair (EVAR) 7 years prior to presentation. Although the sac was stable 6 months ago, the patient presented with shock at arrival, and CT showed aortic rupture with rapid expansion due to type Ib endoleak caused by iliac neck dilatation (IND). The aneurysm sac was excluded using an endovascular strategy. Bell-bottom iliac limbs can cause IND associated with type Ib endoleak. Additionally, the risk of rupture is high when re-expansion of an aneurysm occurs after sac regression after EVAR. Therefore, close follow-up is mandatory for patients with IND after EVAR.

In Vivo Validation of Modulated Acoustic Radiation Force-Based Imaging in Murine Model of Abdominal Aortic Aneurysm Using VEGFR-2-Targeted Microbubbles

OBJECTIVES

The objective of this study is to validate the modulated acoustic radiation force (mARF)-based imaging method in the detection of abdominal aortic aneurysm (AAA) in murine models using vascular endothelial growth factor receptor 2 (VEGFR-2)-targeted microbubbles (MBs).

MATERIALS AND METHODS

The mouse AAA model was prepared using the subcutaneous angiotensin II (Ang II) infusion combined with the β-aminopropionitrile monofumarate solution dissolved in drinking water. The ultrasound imaging session was performed at 7 days, 14 days, 21 days, and 28 days after the osmotic pump implantation. For each imaging session, 10 C57BL/6 mice were implanted with Ang II-filled osmotic pumps, and 5 C57BL/6 mice received saline infusion only as the control group. Biotinylated lipid MBs conjugated to either anti-mouse VEGFR-2 antibody (targeted MBs) or isotype control antibody (control MBs) were prepared before each imaging session and were injected into mice via tail vein catheter. Two separate transducers were colocalized to image the AAA and apply ARF to translate MBs simultaneously. After each imaging session, tissue was harvested and the aortas were used for VEGFR-2 immunostaining analysis. From the collected ultrasound image data, the signal magnitude response of the adherent targeted MBs was analyzed, and a parameter, residual-to-saturation ratio ( Rres - sat ), was defined to measure the enhancement in the adherent targeted MBs signal after the cessation of ARF compared with the initial signal intensity. Statistical analysis was performed with the Welch t test and analysis of variance test.

RESULTS

The Rres - sat of abdominal aortic segments from Ang II-challenged mice was significantly higher compared with that in the saline-infused control group ( P < 0.001) at all 4 time points after osmotic pump implantation (1 week to 4 weeks). In control mice, the Rres - sat values were 2.13%, 1.85%, 3.26%, and 4.85% at 1, 2, 3, and 4 weeks postimplantation, respectively. In stark contrast, the Rres - sat values for the mice with Ang II-induced AAA lesions were 9.20%, 20.6%, 22.7%, and 31.8%, respectively. It is worth noting that there was a significant difference between the Rres - sat for Ang II-infused mice at all 4 time points ( P < 0.005), a finding not present in the saline-infused mice. Immunostaining results revealed the VEGFR-2 expression was increased in the abdominal aortic segments of Ang II-infused mice compared with the control group.

CONCLUSIONS

The mARF-based imaging technique was validated in vivo using a murine model of AAA and VEGFR-2-targeted MBs. Results in this study indicated that the mARF-based imaging technique has the ability to detect and assess AAA growth at early stages based on the signal intensity of adherent targeted MBs, which is correlated with the expression level of the desired molecular biomarker. The results may suggest, in very long term, a pathway toward eventual clinical implementation for an ultrasound molecular imaging-based approach to AAA risk assessment in asymptomatic patients.