Non-surgical strategies to improve timely recognition and management of patients with ruptured abdominal aortic aneurysm across prehospital and hospital settings—a scoping review

Introduction

Background

A ruptured abdominal aortic aneurysm (rAAA) is a life-threatening condition, with a mortality rate of 80–90% (1). Organization of care from early detection to surgical intervention for rAAA patients is challenging for several reasons. First, the acute care chain consists of multiple health care workers, e.g., general practitioners, triage nurses, ambulance personnel (including control room operators) and other paramedics in the prehospital setting, and emergency care nurses and physicians, vascular surgeons and interventional radiologists in the hospital setting. Most patients with rAAA do not reach the hospital in time, and prehospital mortality rate is high (32% of rAAA patients died before reaching the hospital in a systematic review) (1). In a study of the annual report of 240 sentinel events at Dutch out-of-hours primary care services, it was observed that rAAA came in second place of most often missed diagnosis: 7.9% of sentinel events involved an rAAA, while acute coronary syndrome came in first place with 30.4% (2). In root cause analysis of sentinel events involving rAAA, a fluctuation in the course of symptoms (with initially severe pain that later diminishes) was considered to be a remarkable sign (3). Moreover, rAAA surgery cannot be performed in every hospital, so immediate referral to an appropriate hospital is another challenge (4). However, the most important challenge is the acute rupture itself that in general gives health care workers only minutes and in the best case only hours of time (5-7).

Rationale and knowledge gap

To improve survival of rAAA, early detection and timely treatment is critical, but challenging. The classical triad of hypotension, abdominal and/or back pain, and a pulsatile abdominal mass are present in only 50% of rAAA patients (8). There are no clear ‘prodromal symptoms’ and initially rAAA is difficult to differentiate from mimicking conditions such as ureteric colic, gastrointestinal inflammation or perforation, or even acute myocardial infarction when this is causing epigastric pain such as in inferior wall infarction (9-11). A systematic review by Azhar et al. reported an estimate of 32% [95% confidence interval (CI): 16% to 49%] of missed rAAA diagnosis in studies published since 1990 (11). Diagnosis is preferably made through immediate computed tomography angiography (CTA) in all patients suspected of rAAA (Class 1, level B recommendation) (8). Insight into strategies that aim to improve early recognition—notably in the prehospital setting—is an important way to improve care of rAAA and thus ultimately save lives. An overview of strategies across health-care settings to ensure the patient timely reaches the operating room is currently lacking.

Objective

The purpose of this scoping review is to summarize such strategies in cases suspected of rAAA in both the prehospital and hospital setting. Additionally, as a secondary objective, we investigate factors associated with delayed rAAA diagnosis. Surgical and postoperative strategies are beyond the scope of this review. We focus on the patient trajectory from the onset of symptoms until the start of surgery. We present this article in accordance with the PRISMA-ScR reporting checklist (available at https://jeccm.amegroups.com/article/view/10.21037/jeccm-2025-5/rc).

Methods

Inclusion criteria

We conducted a scoping literature review on studies reporting interventions targeted at timely recognition of rAAA and reducing the delay between the onset of symptoms and start of surgery, if performed. With delayed diagnosis, we mean rAAA that was diagnosed too late (including post-mortem diagnosis), i.e., missed. We evaluated all research available on effective practice of care (‘EPOC’) in adult patients with rAAA. Eligible study designs included (parallel or cluster) randomized trials, stepped wedge trials, non-randomized trials with controls (e.g., before and after trials, interrupted time series) and other types of observational studies if they analysed an intervention and reported a comparison between groups. The following PICO (patients, intervention, control, outcome) was formulated to define the search and domain of included studies:

• Patients: patients with rAAA or suspected of rAAA;
• Intervention: non-surgical strategies aimed at improving early recognition and timely management of rAAA across the prehospital and hospital setting, directed at patients, general practitioners, triage nurses, ambulance personnel and other paramedics, emergency care physicians, (vascular) surgeons and (intervention) radiologists;
• Control: care as usual;
• Outcome: pre- or perioperative mortality, vascular mortality, all-cause mortality, quality of life.

For our secondary objective, the outcome of interest was factors associated with delayed rAAA diagnosis. As can be seen in the Appendix 1, the scoping search was broad enough to also yield studies for the secondary objective.

After retrieval, snowballing was employed as a supplementary search strategy to enhance the comprehensiveness of the review. This process allowed for the identification of additional studies that may not have been captured through the initial database searches, thereby reducing the risk of missing key literature due to variations in terminology or indexing.

Figure 1 shows the different parts of the possible rAAA patient journey (which can vary per country depending on whether or not a primary care setting is in place, for example) from the onset of symptoms until surgery and postoperative care. The blue parts are of interest for this review.

Figure 1 The trajectory of a patient with rAAA. The blue parts are of interest for this review. rAAA, ruptured abdominal aortic aneurysm.

Exclusion criteria

As the domain of this review involved studies aimed at early recognition and timely management of patients presenting with symptoms of possible rAAA, we excluded studies on asymptomatic (non-ruptured) aortic aneurysm, as well as studies on the effect of screening for asymptomatic AAA, or studies on patients in whom rAAA was incorrectly suspected. We also excluded studies on the surgical intervention and postoperative care of rAAA. Finally, we also excluded reviews, case-reports, and observational studies that did not assess predicting variables for misdiagnosis, did not analyse an intervention or lacked a comparison or control group.

Study selection procedure

We performed an initial scoping search in the MEDLINE PubMed database, with the most recently updated search on September 26^th 2024, enabling identification of all relevant studies published before this date. Two researchers screened titles and abstracts of the search results and selected relevant studies for inclusion. Results were discussed with a third researcher where needed. Reference lists were scrutinized for additional studies (snowballing), and the search was updated accordingly.

Results

The search on September 26th 2024 in MEDLINE PubMed yielded 2,476 results, see Appendix 1. After screening title and abstract, 6 studies were included regarding our primary objective (Table 1) and 5 studies regarding our secondary objective (Table 2). We also found a protocol paper by Lewis et al. that describes the design of a prospective observational study assessing the diagnostic accuracy of a prehospital smartphone triage tool for detection of rAAA (24). To the best of our knowledge, the results have not yet been published, so we could not formally include this study in our review. One retrospective study by Lauridsen et al. was not formally included, but reported improved survival and shorter time to surgery among patients who underwent prehospital point-of-care ultrasound (POCUS) (18). Our search yielded no systematic reviews or randomized controlled trials but only observational studies.

Studies evaluating strategies to improve timely management of rAAA

The search yielded five studies that focused on care for patients with rAAA in prehospital and hospital settings. The studies investigated the effect of reorganizing referral strategies, and regional centralization through the establishment of (tertiary care) vascular centres, on (various definitions of) mortality. No studies focused specifically on the pre-hospital phase. The ‘pre-hospital’ starting point in the included studies was the ambulance driving to the vascular centre. An overview of included studies is provided in Table 1. As these studies were quite different in terms of outcome definition and summary statistics, for example, results are described separately below.

Carried out simultaneously with the Amsterdam Acute Aneurysm Trial [comparing endovascular aneurysm repair (EVAR) to open surgical repair (OSR)], van Beek et al. performed a prospective observational cohort study on the effect of a regional referral system for patients with rAAA. The authors reported that the survival rate of 58.5% in this cohort was higher than a previously reported Dutch admission survival rate of 46%, with a comparable operative survival rate of ~60% suggesting that the potential benefit in survival of 12.5% was related to less mortality before patients reach the operation room, although this can also be due to the difference in time periods compared (1997–2000 in the nationwide study vs. 2004–2011 in the study by Van Beek). Patients managed at a vascular centre had a higher survival rate than patients undergoing surgical intervention at a referral hospital [adjusted odds ratio (OR) 3.18, 95% CI: 1.43–7.04]. The authors conclude that transfer from the referring hospital to the vascular centre was not associated with survival (89/453 patients were transferred, OR 1.07, 95% CI: 0.58–1.98), but unfortunately this was only tested among patients who were surgically treated in the vascular center, excluding those who died during transport or before reaching the operating room (12).

Similarly, in a retrospective study, Warner et al. assessed the impact of regionalizing rAAA care to centres equipped for both open surgical repair (r-OSR) and EVAR (r-EVAR) by vascular surgeons in 451 patients with rAAA. For patients presenting to a community hospital, 30-day mortality was 46%. Among the patients transferred from a community hospital to a tertiary center, 30-day mortality was 27%. In patients presenting directly to and managed at a tertiary, 30-day mortality was also 27%. The authors conclude that regionalization of rAAA repair decreased mortality by approximately 20% (P<0.001), and that transfer did not impact the mortality of r-EVAR at the tertiary centre. However, bias through confounding by indication is very likely to have occurred, as patients considered too unstable for transport probably stayed at the community hospital, and 6% of patients presented at the community hospital received EVAR, compared to 62% of patients presented and treated at the tertiary centre, making this conclusion questionable (13).

Laukontaus et al. reported on the effect of regional centralization and quality improvement in the in-hospital chain of management of rAAA. This consisted of installment of a dedicated vascular service, a new surgical intensive care unit and an increase in available staff or on call, in the Helsinki University Central Hospital in Finland. During the study period, population-based rAAA mortality decreased from 77% to 56% (P<0.001), the operative 30-day mortality decreased from 43% to 19% (P=0.001), and the 90-day rAAA related mortality in this hospital from 54% to 28% (P=0.002) (14). It has to be noted that 15% of patients was not operated in the period before centralization, compared to 8% after centralization, making confounding by indication very likely.

As a fourth example of a study on regionalization of rAAA care, Davies et al. reported on the changes in practice and outcomes after the establishment of an acute aortic treatment center (AATC) to expedite the care of acute aortic syndromes including rAAA from the moment of arrival at the hospital. A dedicated in-hospital AATC pathway required development of the process, operational pathways, and education. It failed to show a benefit in overall survival for acute abdominal and/or thoracic aneurysms though numbers were very small (8 patients with rAAA, total acute AAA mortality was 1% vs. 9% pre-AATC vs. AATC, P=0.005) (15).

As a final example of regionalization, Bounoua et al. performed a retrospective analysis comparing 44 patients treated in the years before the level II trauma designation of the hospital [1985–1999], to 32 patients treated in the 5 years after the designation [1999–2004]. The number of rAAA cases treated per year increased from 3 per year to 8 per year. Overall time to the operating room decreased from 125 to 80 minutes (P=0.001) and 30-day mortality decreased from 73.5% to 46.8% (P=0.02) (16).

A before-after observational study by Yunus et al. did not investigate regionalization, but implemented a multidisciplinary protocol for rAAA management in a tertiary care hospital, alerting a team of 9 staff members once the emergency room physician suspected rAAA after ultrasound or transfer from a referring hospital, followed by a detailed protocol of preoperative and operative measures. Results were described separately for patients who underwent EVAR and for patients who underwent open repair. After protocol implementation, patients undergoing endovascular repair exhibited significantly lower rates of mortality (20.0% vs. 46.2%, P=0.048), all-cause morbidity (44.0% vs. 65.4%, P=0.050), and renal complications (0.0% vs. 15.4%, P=0.036) after implementation. Patients undergoing open repair for a rAAA exhibited significantly lower rates of mortality (27.3% vs. 53.3%, P=0.018) and bowel ischemia (0.0% vs. 26.7%, P=0.035) after implementation. For both endovascular and open repair, median time to incision (0.7 vs. 1.0 hour, P=0.022) and total procedure time (160.5 vs. 180.0 minutes, P=0.039) was significantly shorter after implementation, although small sample size, the observational before-after design and the lack of adjustment for confounders were important limitations to consider (17).

Factors related to delayed diagnosis of rAAA

For our secondary objective, we found 5 studies on factors associated with delayed rAAA diagnosis (Table 2) (9,10,19-21). The definition of delayed (i.e., missed, or initially missed) diagnosis varied among studies, if explained at all. Three studies reported that signs of hemodynamic instability (syncope/collapse, shock, low blood pressure) were associated with a decreased risk of delayed rAAA diagnosis (so indicative of rAAA), although these had important limitations, as can be seen in the last column of Table 2 (9,10,21). One large study using Medicare claims data from the United States reported the age categories 70–74, 75–79 and 80–84 years to be associated with a decreased risk of delayed diagnosis, and several variables to be associated with an increased risk of delayed diagnosis (see Table 2) (20). Unfortunately, no clinical symptoms were assessed in this study, limiting the relevance for daily practice.

Snowballing identified two additional studies relevant to patient outcomes in rAAA. These were from Jessula et al. who examined the impact of geographic distance from a tertiary centre and found that patients residing more than one hour away had significantly higher mortality (OR 1.61, 95% CI: 1.10–2.37, P=0.02). This applied to a substantial proportion of the study population, with 56% living beyond the one-hour threshold (22).

The other study was from Dirks et al. who investigated the prognostic value of the Shock Index and reported that a hospital Shock Index 1.0 was associated with significantly higher in-hospital mortality in patients with suspected rAAA (68.0% vs. 39.0% for Shock Index <1.0, P=0.022), supporting its utility as an early risk stratification tool (23).

Discussion

Key findings

This exploratory review identified six observational studies that evaluated strategies aimed at improving the timely management of patients with rAAA (12-17). Most focused on regional centralization or multidisciplinary care protocols. Five of these studies reported improved survival with regional centralization, but none were of sufficient methodological quality to draw firm conclusions (12-14,16,17). In addition, five studies addressed factors associated with delayed diagnosis of rAAA (9,10,19-21).

Two additional studies provided further insight: it was found that patients residing closer to a tertiary centre had lower mortality (22). Additionally it was shown that a hospital Shock Index ≥1.0 may be useful as an early prognostic marker (23).

Strengths and limitations

A strength of this review is its systematic approach to identifying studies non-surgical strategies to improve outcome of rAAA, including the use of snowballing to capture additional relevant literature. The inclusion of studies addressing both system-level interventions and diagnostic delays allows for a more comprehensive view of opportunities to improve rAAA care.

However, there are several limitations. First, we were unable to provide a flowchart detailing reasons for exclusion of studies, as exclusion reasons were not systematically documented during the selection process. Second, our search strategy was not specifically designed to capture studies on diagnostic delay, which may have led to the omission of relevant research on this secondary outcome.

Comparison with the literature

The finding that regionalization may improve outcomes aligns with prior meta-analyses showing that hospitals with higher annual AAA repair volumes have lower mortality rates (4). However, comparisons remain challenging due to heterogeneity in design, outcomes, and populations.

The study by Jessula et al. supports concerns raised in earlier work about the impact of geographic access on mortality, adding specific quantification to this effect (22). Dirks et al.’s findings on the Shock Index are consistent with broader emergency medicine literature on its prognostic value, though this has not been widely studied in the context of rAAA (23).

Explanations of findings

When interpreting the results, it is important to realize that all included studies were observational, with a high risk of bias due to confounding by indication, lack of adjustment for key variables, and outcome assessment without blinding. Many were underpowered, and several compared historical to recent cohorts without accounting for changes in surgical techniques or care pathways over time.

Several potential mechanisms may explain the observed association between regionalization and improved survival, including faster access to specialized surgical teams, streamlined care protocols, and greater experience with rAAA management in vascular centers. However, the high risk of immortal time bias and confounding by indication limits the reliability of these conclusions.

The lack of signs of hemodynamic instability in some patients with delayed diagnosis (Table 2) supports the notion that stable-appearing patients are at risk of underdiagnosis or incorrect triage, especially in primary care and out-of-hours services.

Implications and actions needed

Improving the early recognition and timely referral of rAAA requires a shift in focus toward the prehospital phase. Future trials or prospective studies should evaluate the implementation of structured triage protocols, risk stratification tools [e.g., Shock Index (23)], and diagnostic aids such as POCUS (18), especially in general practice and ambulance settings. These interventions may be particularly impactful in rural or remote regions, where time to definitive care is longer. Given the low incidence of rAAA, multicenter collaboration is essential in such studies to ensure adequate sample sizes, which would also enable adjustment for multiple confounders.

Conclusions

This scoping review reveals a lack of high-quality evidence on non-surgical strategies for early recognition and timely management of rAAA. Although regionalization of care may be associated with improved outcomes, the evidence is methodologically limited and prone to bias. The absence of hemodynamic instability is a key factor in delayed diagnosis, underscoring the need for improved diagnostic strategies in primary care and ambulance services. Future research should therefore prioritize prospective studies evaluating triage tools, prehospital diagnostics such as POCUS, and system-level interventions to reduce time to surgical care, particularly in geographically dispersed settings.

Acknowledgments

We would like to thank Sander van Doorn, MD, PhD and Carmen Erkelens, MD, PhD for their efforts in conducting the literature search, study selection and writing of the first draft of the manuscript.

Footnote

Reporting Checklist: The authors have completed the PRISMA-ScR reporting checklist. Available at https://jeccm.amegroups.com/article/view/10.21037/jeccm-2025-5/rc

Peer Review File: Available at https://jeccm.amegroups.com/article/view/10.21037/jeccm-2025-5/prf

Funding: This work was supported by ZonMw (grant No. 80-83935-98-142). The funder was not involved in the design or conduct of the study or writing of the manuscript.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jeccm.amegroups.com/article/view/10.21037/jeccm-2025-5/coif). S.O. is the owner and founder of Veiliger Zorg, which is a non-profit organization. The other authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Reimerink JJ, van der Laan MJ, Koelemay MJ, et al. Systematic review and meta-analysis of population-based mortality from ruptured abdominal aortic aneurysm. Br J Surg 2013;100:1405-13. [Crossref] [PubMed]
2. Rutten MH, Kant J, Giesen P. What can we learn from calamities at out-of-hours services in primary care? Huisarts Wet 2018;61:1-4.
3. Oomkens S, Van de Kar C. Leren van de top 6 oorzaken van calamiteiten 2020:1-5. Available online: https://www.henw.org/system/files/attachments/2020-06/Webjournaal%20Van%20Kimmenaede_Calamiteit%20HAP_Onderzoek_InEen.pdf#:~:text=LEREN%20VAN%20DE%20TOP%20ZES%20OORZAKEN%20VAN%20CALAMITEITEN.%20ONDERZOEKSRESULTATEN%20EN (accessed October 3, 2024).
4. Holt PJ, Poloniecki JD, Gerrard D, et al. Meta-analysis and systematic review of the relationship between volume and outcome in abdominal aortic aneurysm surgery. Br J Surg 2007;94:395-403. [Crossref] [PubMed]
5. Rinckenbach S, Albertini JN, Thaveau F, et al. Prehospital treatment of infrarenal ruptured abdominal aortic aneurysms: a multicentric analysis. Ann Vasc Surg 2010;24:308-14. [Crossref] [PubMed]
6. Walker EM, Hopkinson BR, Makin GS. Unoperated abdominal aortic aneurysm: presentation and natural history. Ann R Coll Surg Engl 1983;65:311-3.
7. Boyle JR, Gibbs PJ, Kruger A, et al. Existing delays following the presentation of ruptured abdominal aortic aneurysm allow sufficient time to assess patients for endovascular repair. Eur J Vasc Endovasc Surg 2005;29:505-9. [Crossref] [PubMed]
8. Wanhainen A, Van Herzeele I, Bastos Goncalves F, et al. European Society for Vascular Surgery (ESVS) 2024 Clinical Practice Guidelines on the Management of Abdominal Aorto-Iliac Artery Aneurysms. Eur J Vasc Endovasc Surg 2024;67:192-331. [Crossref] [PubMed]
9. Metcalfe D, Sugand K, Thrumurthy SG, et al. Diagnosis of ruptured abdominal aortic aneurysm: a multicentre cohort study. Eur J Emerg Med 2016;23:386-90. [Crossref] [PubMed]
10. Gaughan M, McIntosh D, Brown A, et al. Emergency abdominal aortic aneurysm presenting without haemodynamic shock is associated with misdiagnosis and delay in appropriate clinical management. Emerg Med J 2009;26:334-9. [Crossref] [PubMed]
11. Azhar B, Patel SR, Holt PJ, et al. Misdiagnosis of ruptured abdominal aortic aneurysm: systematic review and meta-analysis. J Endovasc Ther 2014;21:568-75. [Crossref] [PubMed]
12. van Beek SC, Reimerink JJ, Vahl AC, et al. Effect of regional cooperation on outcomes from ruptured abdominal aortic aneurysm. Br J Surg 2014;101:794-801. [Crossref] [PubMed]
13. Warner CJ, Roddy SP, Chang BB, et al. Regionalization of Emergent Vascular Surgery for Patients With Ruptured AAA Improves Outcomes. Ann Surg 2016;264:538-43. [Crossref] [PubMed]
14. Laukontaus SJ, Aho PS, Pettilä V, et al. Decrease of mortality of ruptured abdominal aortic aneurysm after centralization and in-hospital quality improvement of vascular service. Ann Vasc Surg 2007;21:580-5. [Crossref] [PubMed]
15. Davies MG, Younes HK, Harris PW, et al. Outcomes before and after initiation of an acute aortic treatment center. J Vasc Surg 2010;52:1478-85. [Crossref] [PubMed]
16. Bounoua F, Schuster R, Grewal P, et al. Ruptured abdominal aortic aneurysm: does trauma center designation affect outcome? Ann Vasc Surg 2007;21:133-6. [Crossref] [PubMed]
17. Yunus RA, Saeed S, Levy N, et al. A Multidisciplinary Protocolized Approach for Ruptured Abdominal Aortic Aneurysm Management: A Retrospective Before-After Study. J Cardiothorac Vasc Anesth 2024;38:755-70. [Crossref] [PubMed]
18. Lauridsen SV, Bøtker MT, Eldrup N, et al. Prehospital point-of-care ultrasound in ruptured abdominal aortic aneurysms-a retrospective cohort study. Acta Anaesthesiol Scand 2024;68:693-701. [Crossref] [PubMed]
19. Acheson AG, Graham AN, Weir C, et al. Prospective study on factors delaying surgery in ruptured abdominal aortic aneurysms. J R Coll Surg Edinb 1998;43:182-4.
20. Waxman DA, Kanzaria HK, Schriger DL. Unrecognized Cardiovascular Emergencies Among Medicare Patients. JAMA Intern Med 2018;178:477-84. [Crossref] [PubMed]
21. Smidfelt K, Nordanstig J, Davidsson A, et al. Misdiagnosis of ruptured abdominal aortic aneurysms is common and is associated with increased mortality. J Vasc Surg 2021;73:476-483.e3. [Crossref] [PubMed]
22. Jessula S, Cote CL, Cooper M, et al. Dying to Get There: Patients Who Reside at Increased Distance from Tertiary Center Experience Increased Mortality Following Abdominal Aortic Aneurysm Rupture. Ann Vasc Surg 2023;91:135-44. [Crossref] [PubMed]
23. Dirks NPM, Mestrom M, van der Lugt M, et al. Utility of Shock Index for Suspected Rupture of Abdominal Aortic Aneurysms. Prehosp Emerg Care 2021;25:496-503. [Crossref] [PubMed]
24. Lewis TL, Fothergill RTAneurysm-FILTR Study Group, et al. Ambulance smartphone tool for field triage of ruptured aortic aneurysms (FILTR): study protocol for a prospective observational validation of diagnostic accuracy. BMJ Open 2016;6:e011308. [Crossref] [PubMed]