Nationwide Analysis of Ruptured Abdominal Aortic Aneurysm in Portugal (2000-2015)

How to improve epidemiological trustworthiness concerning abdominal aortic aneurysms

BACKGROUND

Research on degenerative abdominal aortic aneurysms (AAA) is hampered by complex pathophysiology, sub-optimal pre-clinical models, and lack of effective medical therapies. In addition, trustworthiness of existing epidemiological data is impaired by elements of ambiguity, inaccuracy, and inconsistency. Our aim is to foster debate concerning the trustworthiness of AAA epidemiological data and to discuss potential solutions.

METHODS

We searched the literature from the last five decades for relevant epidemiological data concerning AAA development, rupture, and repair. We then discussed the main issues burdening existing AAA epidemiological figures and proposed suggestions potentially beneficial to AAA diagnosis, prognostication, and management.

RESULTS

Recent data suggest a heterogeneous scenario concerning AAA epidemiology with rates markedly varying by country and study cohorts. Overall, AAA prevalence seems to be decreasing worldwide while mortality is apparently increasing regardless of recent improvements in aortic-repair techniques. Prevalence and mortality are decreasing in high-income countries, whereas low-income countries show an increase in both. However, several pieces of information are missing or outdated, thus systematic renewal is necessary. Current AAA definition and surgical criteria do not consider inter-individual variability of baseline aortic size, further decreasing their reliability.

CONCLUSIONS

Switching from flat aortic-size thresholds to relative aortic indices would improve epidemiological trustworthiness regarding AAAs. Aortometry standardization focusing on simplicity, univocity, and accuracy is crucial. A patient-tailored approach integrating clinical data, multi-adjusted indices, and imaging parameters is desirable. Several novel imaging modalities boast promising profiles for investigating the aortic wall. New contrast agents, computational analyses, and artificial intelligence-powered software could provide further improvements.

Next-Generation Sequencing of microRNAs in Small Abdominal Aortic Aneurysms: MiR-24 as a Biomarker

BACKGROUND

Small abdominal aortic aneurysms (AAAs) are asymptomatic but can potentially lead to rupture if left undetected. To date, there is a lack of simple nonradiologic routine tests available for diagnosing AAAs. MicroRNAs (miRNAs) have been proven to be good-quality biomarkers in several diseases, including AAA.

METHODS

An attempt to identify a panel of circulating miRNAs with differential expression in AAAs via next-generation sequencing (NGS) was performed in serum samples: small AAAs (n = 3), large AAAs (n = 3), and controls (n = 3). For miR-24, validation with real-time polymerase chain reaction (PCR) was undertaken in a larger group (n = 80).

RESULTS

In the NGS study, 23 miRNAs were identified as differentially expressed (with statistical significance) in small AAAs in comparison with controls. Among them, miR-24 showed the largest upregulation with 23-fold change (log2FC 4.5, P = 0.024). For large AAAs compared with controls, and small AAAs compared with large AAAs, a panel of 33 and 131 miRNAs showed statistically significant differential expression, respectively. Based on the results of the NGS stage, a literature search was performed, and information regarding AAA pathogenesis, coronary artery disease, and peripheral arterial disease was documented where applicable: miR-24, miR-103, miR-193a, miR-486, miR-582, and miR-3663. Of these 6 miRNAs, miR-24 was chosen for further validation with real-time PCR. Additionally, in the NGS study analysis, 17 miRNAs were common between the small-large AAAs, small AAAs-controls, and large AAAs-controls comparisons: miR-7846, miR-3195, miR-486-2, miR-3194, miR-5589, miR-1538, miR-3178, miR-4771-1, miR-5695, miR-6504, miR-1908, miR-6823, miR-3159, miR-23a, miR-7853, miR-496, and miR-193a. Interestingly, in the validation stage with real-time PCR, miR-24 was found downregulated in small and large AAAs compared with controls (fold-changes: 0.27, P = 0.015 and 0.15, P = 0.005, respectively). No correlation was found between average Ct values, aneurysm diameter, and patients' age.

CONCLUSIONS

Our findings further highlight the importance of miR-24 as a potential biomarker as well as a therapeutic target for abdominal aneurysmal disease. Future research and validation of a panel of miRNAs for AAA would aid in diagnosis and discrimination between diseases with overlapping pathogeneses.

The Impact of Intra-Operative Heparin on Thromboembolism and Death in a Matched Cohort of Patients with a Ruptured Abdominal Aortic Aneurysm

Objective

Portuguese nationwide estimates indicate that 20% of abdominal aortic aneurysms (AAAs) are treated when ruptured. In these cases, intra-operative unfractionated heparin (UFH) usage rates vary widely. Evidence on this topic is scarce and focused on patients treated by open repair (OSR). The aim was to determine the influence of UFH on peri-operative thromboembolic events (TEs) and death in a cohort of ruptured AAA (rAAA).

Methods

Retrospective, single-centre, comparative study. From 2011 to April 2023, all consecutive rAAAs (endovascular repair [EVAR] and OSR) were considered. Primary outcomes were 30-day TE free survival and TE rates. The secondary outcome was 30-day death. Safety endpoints were procedural blood loss, blood product requirements, and secondary interventions due to haemorrhage. Using propensity score matching (PSM) each UFH patient was matched with one no UFH patient in a 1:1 ratio.

Results

The study included 250 patients. After PSM, 190 patients were analysed (EVAR: 60.0% no-UFH vs. 64.4% UFH). TE free survival estimates favoured the UFH group (67.3% vs. 47.2%, p = .009; UFH adjusted odds ratio [aOR] 2.01, 95% confidence interval [CI] 1.04-4.17). TEs were more frequent in the no UFH group (20.0% vs. 44.2% patients, p < .001; UFH aOR 0.31, 95% CI 0.15-0.65 for any TE), driven by an increase in bowel ischaemia (17.9% no UFH vs. 3.2% UFH, p = .001). Most events occurred in the first 72 hours. EVAR was associated with reduced TE and improved TE free survival (aOR 0.20, 95% CI 0.09-0.45 and aOR 5.54, 95% CI 2.34-13.08, respectively). No significant differences in 30-day survival were noted (75% no-UFH vs. 83% UFH, p = .26; aOR 1.08, 95% CI 0.48-2.43) nor in blood loss, peri-operative red blood cell and fresh frozen plasma requirements, or secondary interventions due to haemorrhage (p = .10; p = .11; p = .13 and p = .18 respectively).

Conclusion

In this cohort, intra-operative UFH was safe and associated with improved TE free survival, driven by a reduction in bowel ischaemia. Conversely, mortality remained unaffected. Randomised controlled trials are required to confirm these findings.

Treatment Outcomes of Patients With Ruptured Abdominal Aortic Aneurysms

BACKGROUND

Ruptured abdominal aortic aneurysm (rAAA) is a serious complication of abdominal aortic aneurysm associated with high operative mortality and morbidity rates. The present study evaluated the perioperative and long-term outcomes of Korean patients with rAAA based on national health insurance claims data.

METHODS

The National Health Insurance Service (NHIS) database was searched retrospectively to identify patients with rAAA who underwent endovascular aneurysm repair (EVAR) and open surgical repair (OSR) from 2009 to 2018. Perioperative (≤ 30 days), early postoperative (≤ 3 month), and long-term (> 3 month) survival, reinterventions, and complications were assessed.

RESULTS

The search identified 1,034 patients with rAAA, including 594 who underwent EVAR and 440 who underwent OSR. When the study period was divided into two, the total numbers of patients with rAAA, patients who underwent EVAR, and octogenarians were higher during the second half. The perioperative mortality rate was 29.8% in the EVAR and 35.0% in the OSR group (P = 0.028). Hartmann's procedure for bowel infarction was performed more frequently in the OSR than in the EVAR group (adjusted odds ratio, 6.28; 95% confidence interval [CI], 2.33-21.84; P = 0.001), but other complication rates did not differ significantly. All-cause mortality during the entire observation period did not differ significantly in the EVAR and OSR groups (adjusted hazard ratio, 1.17; 95% CI, 0.98-1.41; P = 0.087). Abdominal aortic aneurysm-related reintervention rate was significantly lower in the OSR group (adjusted hazard ratio, 0.31; 95% CI, 0.14-0.70; P = 0.005).

CONCLUSION

Although EVAR showed somewhat superior perioperative outcomes for rAAA, the long-term outcomes of EVAR after excluding initial 3 months were significantly worse than OSR. When anatomically feasible for both treatments, the perioperative mortality risk and reasonable prospects of long-term survival should be considered in rAAA.

Nationwide Outcomes of Octogenarians Following Open or Endovascular Management After Ruptured Abdominal Aortic Aneurysms

PURPOSE

Octogenarians are known to have less-favorable outcomes following ruptured abdominal aortic aneurysm (rAAA) repair compared with their younger counterparts. Accurate information regarding perioperative outcomes following rAAA-repair is important to evaluate current treatment practice. The aim of this study was to evaluate perioperative outcomes of octogenarians and to identify factors associated with mortality and major complications after open surgical repair (OSR) or endovascular aneurysm repair (EVAR) of a rAAA using nationwide, real-world, contemporary data.

METHODS

All patients that underwent EVAR or OSR of an infrarenal or juxtarenal rAAA between January 1, 2013, and December 31, 2018, were prospectively registered in the Dutch Surgical Aneurysm Audit (DSAA) and included in this study. The primary outcome was the comparison of perioperative outcomes of octogenarians versus non-octogenarians, including adjustment for confounders. Secondary outcomes were the identification of factors associated with mortality and major complications in octogenarians.

RESULTS

The study included 2879 patients, of which 1146 were treated by EVAR (382 octogenarians, 33%) and 1733 were treated by OSR (410 octogenarians, 24%). Perioperative mortality of octogenarians following EVAR was 37.2% versus 14.8% in non-octogenarians (adjusted OR=2.9, 95% CI=2.8-3.0) and 50.0% versus 29.4% following OSR (adjusted OR=2.2, 95% CI=2.2-2.3). Major complication rates of octogenarians were 55.4% versus 31.8% in non-octogenarians following EVAR (OR=2.7, 95% CI=2.1-3.4), and 68% versus 49% following OSR (OR=2.2, 95% CI=1.8-2.8). Following EVAR, 30.6% of the octogenarians had an uncomplicated perioperative course (UPC) versus 49.5% in non-octogenarians (OR=0.5, 95% CI=0.4-0.6), while following OSR, UPC rates were 20.7% in octogenarians versus 32.6% in non-octogenarians (OR=0.5, 95% CI=0.4-0.7). Cardiac or pulmonary comorbidity and loss of consciousness were associated with mortality and major complications in octogenarians. Interestingly, female octogenarians had lower mortality rates following EVAR than male octogenarians (adjusted OR=0.7, 95% CI=0.6-0.8).

CONCLUSION

Based on this nationwide study with real-world registry data, mortality rates of octogenarians following ruptured AAA-repair were high, especially after OSR. However, a substantial proportion of these octogenarians following OSR and EVAR had an uneventful recovery. Known preoperative factors do influence perioperative outcomes and reflect current treatment practice.

Successful short interval staged surgery in synchronous type A aortic dissection and giant abdominal aortic aneurysm patient

The surgical therapy of synchronous type A aortic dissection and abdominal aortic aneurysm is complex and rarely reported, especially, when the abdominal aortic aneurysm is unsuitable for intervention. Recently, we have successfully performed sequential two staged surgeries on a 46-year-old woman. The first stage surgeries consisted of the Bentall procedure, total aortic arch replacement, and frozen elephant trunk implantation. The second stage surgeries included replacement from the descending aorta to the sub-renal abdominal aorta, reconstruction of the blood flow to the spinal, the celiac trunk artery, the left and right renal artery, the superior and inferior mesenteric artery, and the iliac artery of both sides. The interval between two surgeries was very short (42 days). The patient was recovered, and all functions of her body were reserved. According to our experience, it is feasible to prevent aortic rupture by short interval staged surgery in selected patients with synchronous type A aortic dissection and un-interventionable abdominal aortic aneurysm.

Epidemiology of Abdominal Aortic Aneurysm Repair in Brazil from 2008 to 2019 and Comprehensive Review of Nationwide Statistics Across the World

INTRODUCTION

Studying epidemiology of abdominal aortic aneurysms repairs is essential to prevent related deaths. Although outcomes are influenced by socioeconomic factors, there are no nationwide studies on these statistics in low-and-middle income countries. Therefore, we designed this study to evaluate abdominal aortic aneurysms repair rates, trends, costs, and in-hospital mortality in the Brazilian Public Health System, which exclusively insures over 160 million Brazilians.

MATERIAL AND METHODS

Retrospective cross-sectional population-based analysis of publicly available data referring to all abdominal aortic aneurysm repairs performed between 2008 and 2019 in Brazilian public hospitals.

RESULTS

We observed a total of 13,506 abdominal aortic aneurysm repairs, of which 32% were emergency endovascular repairs, 20% emergency open repairs, 32% elective endovascular repairs and 16% elective open repairs. There has been a downward trend in total abdominal aortic aneurysms repairs and an increasing predominance of endovascular repair. Elective and endovascular repairs were significantly associated with lower in-hospital mortality. For ruptured abdominal aortic aneurysms, we observed mortality rates of 13.8% after endovascular repair and 52.1% after open repair. For intact abdominal aortic aneurysms, we observed mortalities of 3.8% after endovascular repair and 18.6% after open repair. Procedure and mortality rates varied significantly among the Brazilian regions.

CONCLUSIONS

We observed a low and decreasing rate of abdominal aortic aneurysm repair. Most repairs were emergency and endovascular and there was an increasing predominance of endovascular repair. Endovascular and elective repairs were associated with lower mortality.

Screening for Abdominal Aortic Aneurysms and Risk Factors in 65-Year-Old Men in Oslo, Norway

Purpose

To investigate the prevalence of and risk factors for abdominal aortic aneurysm (AAA) in 65-year-old men in Oslo, Norway.

Materials and Methods

From May 2011, until September 2019, the annual population of 65-year-old men living in Oslo were invited to an ultrasonographic screening of the abdominal aorta. Candidates received a one-time invitation by mail, including a questionnaire on possible risk factors and comorbidities. Abdominal aortic outer-to-outer diameter and ankle-brachial index were measured by the screening team. Participants were allocated into three groups: non-, sub- and aneurysmal aorta. Written information on recommended follow-up regime was given to participants with an aortic diameter ≥25 mm. Univariate and multivariate analyses of potential risk factors were performed, in addition to descriptive analyses and significance testing.

Results

In total, 19,328 were invited, 13,215 men were screened, of which 12,822 accepted inclusion in the study. Aortic diameter was registered for 12,810 participants and 330 men had aortic diameter ≥30 mm, giving a prevalence of AAA of 2.6% (95% confidence interval (CI) 2.31-2.86). We identified 4 independent risk factors for AAA: smoking (OR = 3.64, 95% CI 2.90-4.58), hypertension (OR = 1.87, 95% CI 1.49-2.35), BMI >30 (OR = 1.02, 95% CI 1.00-1.03), and diabetes mellitus (OR = 0.52, 95% CI 0.35-0.79), the latter showing an inverse association with AAA growth. A subgroup of 862 men with aortic diameters 25-29 mm had a significantly higher prevalence of BMI >25, smoking and family history of AAA, compared to participants with aortic diameter <25 mm.

Conclusion

Among the participants in this study, the prevalence of abdominal aortic aneurysms was 2.6%. Participants with AAA more frequently reported cardiovascular risk factors, and less frequently diabetes mellitus.

Incidental abdominal aortic aneurysms are largely undocumented and unmonitored

BACKGROUND

In countries without organized population screening, incidental detection remains the major form of abdominal aortic aneurysm (AAA) diagnosis. Despite the presumed homogeneity in AAA prevalence, its rate of repair is highly variable, with Portugal treating 2 to 6 times fewer AAA per habitant than other western countries.

OBJECTIVES

To evaluate the detection rate and monitoring of incidental AAA in a multicentre cohort from Portuguese hospitals.

METHODS

All abdominal CT scans performed in men ≥ 65 years old in three major Portuguese hospitals between January and June 2018 were selected for review. CT scans prescribed by the Vascular Surgery or Emergency Departments were excluded. Patients with previously known AAA were also excluded. Subjects with newly detected aneurysms were assessed for the two primary outcomes: the description of the finding by the radiologist in the written report; the effective follow-up recommendations by the prescriber of the CT or by the general practitioner (GP). Patients with newly found AAA that met criteria for monitoring or treatment and failed to be given guidance were contacted and included in surveillance programs.

RESULTS

Overall, 3292 abdominal CT scans were selected for review. A total of 133 newly found aneurysms were detected (4.2% prevalence in the cohort). Of those, 48 cases (36%) were not described by the radiologist in the written report. Further 42 patients (32%) were not successfully oriented by the ordering physician or GP, despite having had their AAA mentioned. Overall, only 32% (n = 42) of the newly diagnosed AAA were correctly identified and referred to monitoring.

CONCLUSIONS

Incidental AAA is a common occurrence in in-hospital abdominal CTs. A significant number is not documented by the radiologist and the vast majority is not referred to monitoring. This could be a major reason for the low elective treatment rate of AAA in Portugal.