Diagnostic accuracy of non-radiologist performed ultrasound for abdominal aortic aneurysm: systematic review and meta-analysis

Evaluation of point-of-care ultrasound use in the diagnostic approach for right upper quadrant abdominal pain management in the emergency department: a prospective study

Point-of-care ultrasound (PoCUS) is commonly used at the bedside in the emergency department (ED) as part of clinical examinations. Studies frequently investigate PoCUS diagnostic accuracy, although its contribution to the overall diagnostic approach is less often evaluated. The primary objective of this prospective, multicenter, cohort study was to assess the contribution of PoCUS to the overall diagnostic approach of patients with right upper quadrant abdominal pain. Two independent members of an adjudication committee, who were blind to the intervention, independently evaluated the diagnostic approaches before and after PoCUS for the same patient. The study included 62 patients admitted to the ED with non-traumatic right upper quadrant abdominal pain from September 1, 2022, to March 6, 2023. The contribution of PoCUS to the diagnostic approach was evaluated using a proportion test assuming that 75% of diagnostic approaches would be better or comparable with PoCUS. Wilcoxon signed-rank tests evaluated the impact of PoCUS on the mean number of differential diagnoses, planned treatments, and complementary diagnostic tests. Overall, 60 (97%) diagnostic approaches were comparable or better with PoCUS (χ2 = 15.9, p < 0.01). With PoCUS, the mean number of differential diagnoses significantly decreased by 2.3 (95% CI - 2.7 to - 1.5) (p < 0.01), proposed treatments by 1.3 (95% CI - 1.8 to - 0.9) (p < 0.01), and complementary diagnostic tests by 1.3 (95% CI - 1.7 to - 1.0) (p < 0.01). These findings show that PoCUS positively impacts the diagnostic approach and significantly decreases the mean number of differential diagnoses, treatments, and complementary tests.

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.

Editor's Choice - Comparison of the Reproducibility of Ultrasound Calliper Placement Methods in Abdominal Aortic Diameter Measurements: A Systematic Review and Meta-Analysis of Diagnostic Test Accuracy Studies

OBJECTIVE

To assess which ultrasound (US) method of maximum anteroposterior (AP) abdominal aortic diameter measurement can be considered most reproducible.

DATA SOURCES

MEDLINE, Scopus, and Web of Science were searched (PROSPERO ID: 276694). Eligible studies reported intra- and or interobserver agreement according to Bland-Altman analysis (mean ± standard deviation [SD]) for abdominal aortic diameter AP US evaluations with an outer to outer (OTO), inner to inner (ITI), and or leading edge to leading edge (LELE) calliper placement.

REVIEW METHODS

The Preferred Reporting Items for a Systematic Review and Meta-Analysis of Diagnostic Test Accuracy Studies statement was followed. The QUADAS-2 tool and QUADAS-C extension were used for risk of bias assessment and the GRADE framework to rate the certainty of evidence. Pooled estimates (fixed effects meta-analysis, after a test of homogeneity of means) for each US method were compared with pairwise one sided t tests. Sensitivity analyses (for studies published in 2010 or later) and meta-regression were also performed.

RESULTS

21 studies were included in the qualitative analysis. Twelve were eligible for quantitative analysis. Studies showed heterogeneity in the US model and transducer used, sex of participants, and observer professions, expertise, and training. Included studies shared a common mean for each US method (OTO: p = 1.0, ITI: p = 1.0, and LELE: p = 1.0). A pooled estimate of interobserver reproducibility for each US method was obtained, combining the mean ± SD (Bland-Altman analysis) from each study: OTO: 0.182 ± 0.440; ITI: 0.170 ± 0.554; and LELE: 0.437 ± 0.419. There were no statistically significant differences between the methods (OTO vs. ITI: p = .52, OTO vs. LELE: p = .069, ITI vs. LELE: p = .17). Considering studies published in 2010 and later, the pooled estimate for LELE was the smallest, without statistically significant differences between the methods. Despite the low risk of bias, the certainty of the evidence for both meta-analysed outcomes remained low.

CONCLUSION

The interobserver reproducibility for OTO and ITI was 2.5 times smaller (indicating better reproducibility) than LELE; however, without statistically significant differences between the methods and low GRADE evidence certainty. Additional data are needed to validate these findings, while inherent differences between the methods need to be emphasised.

Are Advanced Clinical Practitioners perfectly placed to re-report neuroimages to support clinical diagnosis of dementia?

With the ageing population, the prevalence of dementia is increasing worldwide. There is an emphasis on early, timely diagnosis and treatment options for people with a dementia yet wait times from referral to diagnosis have increased. Neuroimaging performed by radiologists is utilised to support dementia diagnosis and some patients will already have a CT scan from a pre-existing condition such as stroke. The purpose of this commentary is to consider whether ACPs who specialise in dementia, are perfectly placed to re-report on pre-existing neuroimages to support the clinical diagnosis of dementia.

Chronic Atherothrombosis in a Sub-Massive Infrarenal Abdominal Aortic Aneurysm in a 91-Year-Old White Male Donor

Screening for abdominal aortic aneurysms became the standard of care in 2005, yet screening procedures continue to be underutilized. While improvements in mortality rates have been noted over the past 15 years, continued patient mortality from ruptured abdominal aortic aneurysms suggests a need for further research, regarding the effectiveness of the current screening process. Abdominal aortic aneurysms can progress silently, and the risk of rupture increases significantly with increase in diameter. We report a large, untreated infrarenal abdominal aortic aneurysm of 17 cm in length and 8 cm in diameter, showing the chronic atherothrombosis discovered in a 91 year-old white male cadaveric donor. A literature review was conducted to elucidate current understanding of the pathology, risk factors, screening recommendations, and treatment options available for abdominal aortic aneurysms.

The Ratio of the Size of the Abdominal Aortic Aneurysm to That of the Unchanged Aorta as a Risk Factor for Its Rupture

Background: A ruptured abdominal aortic aneurysm is a severe condition associated with high mortality. Currently, the most important criterion used to estimate the risk of its rupture is the size of the aneurysm, but due to patients’ anatomical variability, many aneurysms have a high risk of rupture with a small aneurysm size. We asked ourselves whether individual differences in anatomy could be taken into account when assessing the risk of rupture. Methods: Based on the CT scan image, aneurysm and normal aorta diameters were collected from 186 individuals and compared in patients with ruptured and unruptured aneurysms. To take into account anatomical differences between patients, diameter ratios were calculated by dividing the aneurysm diameter by the diameter of the normal aorta at various heights, and then further comparisons were made. Results: It was found that the calculated ratios differ between patients with ruptured and unruptured aneurysms. This observation is also present in patients with small aneurysms, with its maximal size below the level that indicates the need for surgical treatment. For small aneurysms, the ratios help us to estimate the risk of rupture better than the maximum sac size (AUC: 0.783 vs. 0.650). Conclusions: The calculated ratios appear to be a valuable feature to indicate which of the small aneurysms have a high risk of rupture. The obtained results suggest the need for further confirmation of their usefulness in subsequent groups of patients.

Focus on PoCUS or hocus pocus? Integrating point-of-care ultrasound into residency and clinical practice

Point-of care ultrasound (PoCUS) is a new clinical diagnostic paradigm that plays an instrumental role in the ongoing anesthesiologist’s evolving role towards a perioperative physician. Currently, there are few approved curricula that incorporate a PoCUS program into anesthesia residency. This article examines relevant PoCUS applications for anesthesiologists, presents an overview of existing international guidelines for education and training, and reflects on the need for specialty-wide standards. We present a possible framework, that could offer a first move towards a structured PoCUS pathway for Belgian anesthesia residents and facilitate its incorporation into national anesthesia practice.

Intraluminal Thrombus Predicts Rapid Growth of Abdominal Aortic Aneurysms

Background Intraluminal thrombus (ILT) within abdominal aortic aneurysms (AAAs) may be a potential marker for subsequent aneurysm growth. Purpose To investigate the role of ILT in AAA progression as assessed with CT and MRI. Materials and Methods This was a retrospective study, with patient data included from January 2004 to December 2018 at a Veteran Affairs medical center. Male patients with AAA who underwent contrast material-enhanced CT at baseline and CT or black-blood MRI at follow-up (minimal follow-up duration of 6 months) were included. The maximal AAA diameter was measured with multiplanar reconstruction, and the annual growth rate of aneurysms was calculated. Uni- and multivariable linear regression analyses were used to determine the relationship between demographic and imaging factors and aneurysm growth. Results A total of 225 patients (mean age, 72 years ± 9 [standard deviation]) were followed for a mean of 3.3 years ± 2.5. A total of 207 patients were followed up with CT, and 18 were followed up with MRI. At baseline, the median size of the AAA was 3.8 cm (interquartile range [IQR], 3.3-4.3 cm); 127 of 225 patients (54.7%) had ILT. When compared with AAAs without ILT, AAAs with ILT had larger baseline diameters (median, 4.1 cm [IQR, 3.6-4.8 cm] vs 3.4 cm [IQR, 3.2-3.9 cm]; P < .001) and faster growth rates (median, 2.0 mm/y [IQR, 1.3-3.2 mm/y] vs 1.0 mm/y [IQR, 0.4-1.8 mm/y]; P < .001). Small AAAs (size range, 3-4 cm) with ILT grew 1.9-fold faster than did those without ILT (median, 1.5 mm/y [IQR, 0.9-2.7 mm/y] vs 0.8 mm/y [IQR, 0.3-1.5 mm/y]; P < .001). Medium AAAs (size range, 4-5 cm) with ILT had 1.2-fold faster growth than did those without ILT (median growth, 2.1 mm/y [IQR, 1.4, 3.7 mm/y] vs 1.8 mm/y [IQR, 0.9, 2.0 mm/y]; P = .06). In multivariable analysis, baseline diameter and ILT were independently positively related to aneurysm growth rate (standardized regression coefficient, 0.43 [P < .001] and 0.15 [P = .02], respectively). Conclusion Both maximal cross-sectional aneurysm diameter and the presence of intraluminal thrombus are independent predictors of abdominal aortic aneurysm growth. © RSNA, 2020 Online supplemental material is available for this article.

Surgeon-performed point-of-care ultrasound for acute cholecystitis: indications and limitations: a European Society for Trauma and Emergency Surgery (ESTES) consensus statement

BACKGROUND

Acute cholecystitis (AC), frequently responsible for presentation to the emergency department, requires expedient diagnosis and definitive treatment by a general surgeon. Ultrasonography, usually performed by radiology technicians and reported by radiologists, is the first-line imaging study for the assessment of AC. Targeted point-of-care ultrasound (POCUS), particularly in the hands of the treating surgeon, may represent an evolution in surgical decision-making and may expedite care, reducing morbidity and cost.

METHODS

This consensus guideline was written under the auspices of the European Society of Trauma and Emergency Surgery (ESTES) by the POCUS working group. A systematic literature search identified relevant papers on the diagnosis and treatment of AC. Literature was critically-appraised according to the GRADE evidence-based guideline development method. Following a consensus conference at the European Congress of Trauma & Emergency Surgery (Valencia, Spain, May 2018), final recommendations were approved by the working group, using a modified e-Delphi process, and taking into account the level of evidence of the conclusion.

RECOMMENDATIONS

We strongly recommend the use of ultrasound as the first-line imaging investigation for the diagnosis of AC; specifically, we recommend that POCUS may be adopted as the primary imaging adjunct to surgeon-performed assessment of the patient with suspected AC. In line with the Tokyo guidelines, we strongly recommend Murphy's sign, in conjunction with the presence of gallstones and/or wall thickening as diagnostic of AC in the correct clinical context. We conditionally recommend US as a preoperative predictor of difficulty of cholecystectomy. There is insufficient evidence to recommend contrast-enhanced ultrasound or Doppler ultrasonography in the diagnosis of AC. We conditionally recommend the use of ultrasound to guide percutaneous cholecystostomy placement by appropriately-trained practitioners.

CONCLUSIONS

Surgeons have recently embraced POCUS to expedite diagnosis of AC and provide rapid decision-making and early treatment, streamlining the patient pathway and thereby reducing costs and morbidity.

Point-of-Care Ultrasound in Established Settings

The original and most widely accepted applications for point-of-care ultrasound (POCUS) are in the settings of trauma, shock, and bedside procedures. Trauma was the original setting for the introduction of POCUS and has been standardized under the four-plus view examination called the Focused Assessment with Sonography in Trauma (FAST). This examination was found to be especially practice changing for achieving rapid diagnoses in critically ill patients who are too unstable for the delays and transportation inherent in more advanced imaging with computed tomography. This application was broadened from the critically ill trauma patient to any critically ill patient, particularly the patient in undifferentiated shock. Although the Focused Assessment with Sonography in Trauma examination originally focused on sources of hemorrhage causing hypovolemic shock, POCUS also can quickly differentiate cardiogenic, obstructive, and distributive shock and help identify the more specific etiology such as massive pulmonary emboli, pericardial tamponade, and pneumothoraces. By expediting diagnosis, POCUS facilitates faster definitive treatment of life-threatening conditions. In pursuing treatment, US continues to serve a role in the form of visually guiding many procedures that were previously done blindly. US guidance of procedures has improved the safety of central line insertion, thoracentesis, and paracentesis, and has an emerging role in lumbar puncture. Experience in bedside US is becoming a vital tool in the clinician's bedside assessment and management, filling a void between the stethoscope and the more advanced studies and interventions available through radiology. Understanding the strengths and limitations of US enables clinicians to identify the appropriate situations in which they can apply this tool confidently.

Abdominal aortic aneurysm screening: concepts and controversies

Abdominal aortic aneurysms (AAAs) are a leading cause mortality and morbidity but often go undiagnosed until late stages unless imaging is performed. In 2005, the United States Preventive Services Task Force (USPSTF) for the first time recommended one-time ultrasound screening for elderly male smokers and selective screening in other populations. These guidelines were reaffirmed and updated in 2014; a proposal for potential further revisions is now in early planning stages. In this article, we review the past and current USPSTF AAA screening recommendations and techniques for performing optimal screening. Evidence supporting screening and alternative guidelines are also discussed. In addition, emerging concepts and controversies in AAA screening are highlighted, including conflicting data on screening benefits, screening underutilization, inconsistent follow-up recommendations, and the potential for duplicative testing, alternative screening modalities, and clinically significant incidental findings.