Point-of-care Ultrasound Diagnosis of an Atypical Acute Aortic Dissection

Aortic dissection: How to identify it during an abdominal ultrasound examination and achieve a potentially lifesaving diagnosis

Aortic dissection (AD) is a rare and potentially fatal condition that may be diagnosed late. During an emergency or elective abdominal ultrasound (US) examination, when going to evaluate the abdominal aorta for other reasons, it may happen that we find ourselves suspecting an AD. It is therefore important to know the US characteristics of this pathology to avoid wrong or missed diagnoses. Here, we present our practical experience regarding the application of US in the study of the abdominal aorta, which allowed us on several occasions to find an unexpected dissection in patients brought to our attention for other reasons.

The sonographic protocol for the emergent evaluation of aortic dissections (SPEED protocol): A multicenter, prospective, observational study

OBJECTIVES

An aortic dissection (AoD) is a potentially life-threatening emergency with mortality rates exceeding 50%. While computed tomography angiography remains the diagnostic standard, patients may be too unstable to leave the emergency department. Investigators developed a point-of-care ultrasound (POCUS) protocol combining transthoracic echocardiography (TTE) and the abdominal aorta. The study objective was to determine the test characteristics of this protocol.

METHODS

This was an institutional review board-approved, multicenter, prospective, observational, cohort study of a convenience sample of adult patients. Patients suspected of having an AoD received a TTE and abdominal aorta POCUS. Three sonographic signs suggested AoD: a pericardial effusion, an intimal flap, or an aortic outflow track diameter measuring more than 35 mm. Investigators present continuous and categorical data as medians with interquartile ranges or proportions with 95% confidence intervals (CIs) and utilized standard 2 × 2 tables on MedCalc (Version 19.1.6) to calculate test characteristics with 95% CI.

RESULTS

Investigators performed 1314 POCUS examinations, diagnosing 21 Stanford type A and 23 Stanford type B AoD. Forty-one of the 44 cases had at least one of the aforementioned sonographic findings. The protocol has a sensitivity of 93.2% (95% CI 81.3-98.6), specificity of 90.9 (95% CI 89.2-92.5), positive and negative predictive values of 26.3% (95% CI 19.6-33.9) and 99.7% (95% CI 99.2-100), respectively, and an accuracy of 91% (95% CI 89.3-92.5).

CONCLUSIONS

The SPEED protocol has an overall sensitivity of 93.2% for AoD.

Usefulness of point-of-care ultrasound in the atypical presentation of aortic dissection: a case series and brief review of literature

Acute aortic dissection represents a surgical emergency that, in most cases, may present an atypical and non-specific clinic, making the diagnosis difficult and late. Computed tomography angiography represents the gold standard for diagnosis, but different ultrasound techniques are able to provide valuable additional information related to diagnosis, and optimize therapy and prognostic assessment. In this case series, we describe different atypical patterns of aortic dissection, associated to non-diagnostic D-Dimer levels. These atypical conditions escape recognized diagnostic algorithms for the diagnosis of aortic dissection, although the incidence of such events is far from negligible. A clinical approach in the emergency setting that provides for a systematic and standardized use of bedside ultrasound could help reduce the incidence of errors and diagnostic delay, addressing the gold standard instrumental diagnostics for the reference pathology.

Postpartum aortic dissection diagnosed by point-of-care ultrasound in the emergency department: A case study

Aortic dissection is a rare but clinically significant cause of chest pain in the emergency department (ED). While classic risk factors include advanced age, male sex, and tobacco use, pregnancy is also an independent and easily overlooked risk factor. Aortic dissection carries both high maternal and fetal morbidity and mortality. Point-of-care ultrasound is increasingly employed in the ED and has been shown to be useful in the evaluation of abdominal aortic pathologies. We present a case in which abdominal aortic ultrasound was utilized in the diagnosis of an acute Stanford type B aortic dissection in a recently postpartum patient.

Iatrogenic Aortic Dissection Presenting With Leg Pain Diagnosed With Point-of-care Ultrasound

Iatrogenic aortic dissection (IAD) status-post-cardiac catheterization is a rare complication often isolated to the proximal aorta. This is a case of IAD isolated to the distal aorta in a 41-year-old female who presented to the emergency department with right leg pain after undergoing three cardiac catheterizations. The diagnosis of IAD was made upon discovery of an intimal flap in the distal aorta and femoral artery while performing a point-of-care ultrasound to evaluate for deep vein thrombosis.