Point‐of‐care Focused Cardiac Ultrasound for the Assessment of Thoracic Aortic Dimensions,Dilation, and Aneurysmal Disease

Objectives: Thoracic aortic aneurysm and thoracic aortic dissection are related and potentially deadly diseases that present with nonspecific symptoms. Transthoracic echocardiography (TTE) may detect thoracic aortic pathology and is being increasingly performed by the emergency physician at the bedside; however, the accuracy of point‐of‐care (POC) focused cardiac ultrasound (FOCUS) for thoracic aortic aneurysm and thoracic aortic dissection has not been studied. The objective of this pilot study was to explore the agreement, sensitivity, and specificity of FOCUS for thoracic aortic dimensions, dilation, and aneurysm compared with CT angiography (CTA) as the reference standard. Methods: This study was a retrospective pilot analysis of image and chart data on consecutive patients presenting to an urban, academic emergency department (ED) between January 2008 and June 2010, who had both a FOCUS and a CTA for suspicion of thoracic aorta pathology. Thoracic aorta dimensions were measured from recordings by three ultrasound‐trained emergency physicians blinded to any initial FOCUS and CTA results. CTA measurements were obtained by a radiologist blinded to the FOCUS results. Using cutoffs of 40 and 45 mm, we calculated the sensitivity and specificity of FOCUS for aortic dilation and aneurysm with the largest measurement on CT as the reference standard. Bland‐Altman plots with 95% limits of agreement were used to demonstrate agreement for aortic measurements, kappa statistics to assess the degree of agreement between tests for aortic dilation, and intraclass correlation for interobserver and intraobserver variability. Results: Ninety‐two patients underwent both FOCUS and CTA during the study period. Ten FOCUS studies had inadequate visualization for all measurements areas. Eighty‐two patients were included in the final analysis. Mean (±SD) age was 58.1 (±16.6) years and 58.5% were male. Sensitivity, specificity, and the observed kappa value (95% confidence interval [CI]) between FOCUS and CTA for the presence of aortic dilation at the 40‐mm cutoff were 0.77 (95% CI = 0.58 to 0.98), 0.95 (95% CI = 0.84 to 0.99), and 0.74 (95% CI = 0.58 to 0.90), respectively. The mean difference (95% limits of agreement) for the Bland‐Altman plots was 0.6 mm (?5.3 to 6.5) for the sinuses of Valsalva, 4 mm (?2.7 to 10.7) for the sinotubular junction, 1.5 mm (?5.8 to 8.8) for the ascending aorta, and 2.2 mm (?5.9 to 10.3) for the descending aorta. Conclusions: In this retrospective pilot study, FOCUS demonstrated good agreement with CTA measurements of maximal thoracic aortic diameter. FOCUS appears to be specific for aortic dilation and aneurysm when compared to CTA, but requires further prospective study. ACADEMIC EMERGENCY MEDICINE 2012; 19 :1–4 © 2012 by the Society for Academic Emergency Medicine     

Acute aortic dissection: population-based incidence compared with degenerative aortic aneurysm rupture

OBJECTIVES: To ascertain whether acute aortic dissection (AAD) remains the most common aortic catastrophe, as generally believed, and to detect any improvement in outcomes compared with previously reported population-based data. PATIENTS AND METHODS: We determined the incidence, operative intervention rate, and long-term survival rate of Olmsted County, Minnesota, residents with a clinical diagnosis of AAD initially made between 1980 and 1994. The incidence of degenerative thoracic aortic aneurysm (TAA) rupture was also delineated. We compared these results with other population-based studies of AAD, degenerative TAA, and abdominal aortic aneurysm (AAA) rupture. RESULTS: During a 15-year period, we identified 177 patients with thoracic aortic disease. We focused on 39 patients with AAD (22% of the entire cohort) and 28 with TAA rupture (16%). The annual age- and sex-adjusted incidences were 3.5 per 100,000 persons (95% confidence interval, 2.4-4.6) for AAD and 3.5 per 100,000 persons (95% confidence interval, 2.2-4.9) for TAA rupture. Thirty-three dissections (85%) involved the ascending aorta, whereas 6 (15%) involved only the descending aorta. Nineteen patients (49%) underwent 22 operations for AAD, with a 30-day case fatality rate of 9%. Among all 39 patients with AAD, median survival was only 3 days. Overall 5-year survival for those with AAD improved to 32% compared with only 5% in this community between 1951 and 1980. CONCLUSIONS: In other studies, the annual incidences of TAA rupture and AAA rupture are estimated at approximately 3 and 9 per 100,000 persons, respectively. This study indicates that AAD and ruptured degenerative TAA occur with similar frequency but less commonly than ruptured AAA. Although timely recognition and management remain problematic, these new data suggest that recent diagnostic and operative advances are improving long-term survival in AAD.     

Focused Cardiac Ultrasound Diagnosis of Thoracic Aortic Aneurysm: Two Cases

Background

Thoracic aortic aneurysms (TAAs) are less prevalent than abdominal aortic aneurysms. Symptomatic TAAs need to be identified quickly by the emergency physician (EP) since mortality rates increase dramatically once complications such as rupture or dissection occur. Compared with validated EP-performed ultrasound of the abdominal aorta, EP-performed focused cardiac ultrasound that includes evaluation of the thoracic aorta is relatively unreported.

Objective

Two cases illustrate EP-performed focused cardiac ultrasound and evaluation of the thoracic aorta for aneurysmal dilation.

Case Reports

(1) A 60-year-old man presented to the emergency department (ED) after a blunt traumatic injury to his back while at work. During the focused cardiac ultrasound examination, the aortic outflow tract distal to the aortic valve appeared enlarged and the aortic root measured 5.49 cm. (2) An 82-year-old man with hypertension presented to the ED with 1 month of chest pain radiating to the back. The focused cardiac ultrasound examination demonstrated enlargement of the descending thoracic aorta at 4.82 cm.

Conclusion

EPs performing focused cardiac ultrasound can visualize regions of the thoracic aorta that may reveal an aneurysm, particularly in the parasternal long axis view.     

Non-traumatic aortic dissection or rupture as cause of cardiac arrest: presentation and outcome

OBJECTIVE: To evaluate the frequency, presentation and outcome of non-traumatic aortic dissection/rupture as a cause of cardiac arrest. DESIGN: Retrospective analysis of a cardiac arrest registry in a tertiary care hospital emergency department. RESULTS: Over 11.5 years, aortic dissection/rupture was identified as the immediate cause of cardiac arrest in 46 (2,3%) out of 1990 patients with sudden cardiac arrest, primarily affecting the abdominal aorta in 25 and the thoracic aorta in 21 cases. The characteristics of the 46 patients were as follows: male gender (74%), median age 71 years (IQR 59-76), high co-morbidity (89%), previously known aortic aneurysm (33%), pulseless electric activity (70%) as initial cardiac rhythm. When performed, bedside abdominal sonography or echocardiography was almost always diagnostic. Patients with abdominal aortic dissection/rupture had abdominal (52%) and/or flank pain (32%). Patients with thoracic aortic dissection/rupture complained of chest pain (48%) or dyspnoea (19%). Return of spontaneous circulation occurred in 12 (26%) of 46 patients, emergency surgery was performed in eight of these patients, 2 (4%) survived to discharge in good neurological condition. CONCLUSIONS: Cardiac arrest caused by aortic dissection/rupture is rare, and mortality remains very high, even when circulation can be restored initially. Common features such as previously known aortic aneurysm, old age, male gender and pulseless electrical activity as initial cardiac rhythm should increase suspicion of the condition.     

Impact of aortic dimensions and pulse pressure on late aneurysm formation in operated type A aortic dissection. A magnetic resonance imaging study

BACKGROUND: Patients operated on for type A aortic dissection remain at risk of long-term aneurysm development, the main cause for late death. The aim of this study was to identify early predictors for aneurysm formation at three-years after surgery. METHODS: A study group of 70 consecutive patients (52 +/- 10 years-old, 41 male), operated on for aortic dissection with replacement of the ascending segment, was evaluated prospectively for three-years. In order to detect aneurysm formation, the dimension of residual distal aortic segments was obtained soon after surgery and then annually for three years using cardiovascular magnetic resonance. RESULTS: During follow-up (38 +/- 2.6 months), aneurysm was found in 25 patients (35%) involving residual segments. Larger initial dimension of segments, higher pulse pressure, lower distensibility of residual segments and the presence of a residual flap were univariately associated with aneurysm. Multivariate analysis identified the initial dimension (mm) of the descending thoracic aorta (OR 1.47, 95%CI: [1.19-1.82]) and pulse pressure (OR 1.43,95%CI: [1.10-1.86]) as independent variables for aneurysm formation. A risk score using pulse pressure and descending thoracic dimension was constructed. Patients with or=45 yielded 100% of aneurysm frequency. CONCLUSIONS: Type A aortic dissection treated by graft interposition is associated with a high risk of aneurysm formation. Early post-operative pulse pressure and the descending thoracic aortic dimension were independent variables and seem to be the main predictors for the outcome.     

The diagnosis of aortic dissection by emergency medicine ultrasound

A series of five cases of aortic dissection are presented that were diagnosed by emergency physicians using ultrasound to search the abdominal and thoracic aorta for pathology. Aortic dissection is a vascular emergency with a high morbidity and mortality, yet its presentation can be varied and subtle. This article reports the use of Emergency ultrasound in a series of five aortic dissections discovered with a limited, yet timely viewing of the aorta and heart by emergency physicians.     

Utility of common bile duct measurement in ED point of care ultrasound: A prospective study

Background

Measurement of the common bile duct (CBD) is considered a fundamental component of biliary point-of-care ultrasound (POCUS), but can be technically challenging.

Association between bicuspid aortic valve morphotype and regional dilatation of the aortic root and trunk

Thoracic aortic disease, including thoracic aortic aneurysm (TAA), is frequently seen in patients with bicuspid aortic valve (BAV). We hypothesized that BAV morphotype would be associated with aortic aneurysm phenotypes but that other patient variables would significantly modify this relationship. 829 patients between 18 and 90 years with BAV and available raw imaging of the aortic valve and the ascending aorta to its mid-portion prior to aortic valve and aortic surgery were examined. The sinuses of Valsalva and proximal ascending aorta were measured from 2-dimensional co-planar echocardiographic images. We observed strong associations between patient habitus and raw and normalized dimensions of the aortic root and ascending aorta. Patients with R–L morphotype presented at an older age with larger aortic root but similar ascending aortic dimensions. After accounting for patient morphometric characteristics and severity of aortic valve disease, patients with R–L valve morphotype were marginally more likely to have an aortic root aneurysm (86% vs. 78%; P?=?0.043), defined as aortic root dimension Z score ≥3. We observed only small differences in aortic dimensions between BAV morphotypes, that are eclipsed by variation in patient habitus. We interpret these findings to mean that BAV patients will not likely benefit from therapies based on aortic valve morphotype. Rather, we propose that all BAV patients should undergo longitudinal follow-up, independent of valve morphotype. Guidelines for aortic surgery based upon dimensions alone may be improved by considering patient characteristics such as age, body size and other characteristics.     

Sudden death caused by dissecting thoracic aortic aneurysm in a patient with autosomal dominant polycystic kidney disease

Among the fatal vascular complications associated with autosomal dominant polycystic disease (ADPKD), ruptured intracerebral aneurysm and ruptured abdominal aortic aneurysm are widely known. However, there are few reports on the dissecting thoracic aortic aneurysm as a fatal complication of ADPKD. We report a case of a 58-year-old man with a history of ADPKD who presented to the emergency department with out-of-hospital cardiac arrest. Immediate cardiopulmonary resuscitation restored a spontaneous circulation successfully and subsequent image study revealed a type I dissecting thoracic aortic aneurysm. Emergency aortic grafting was performed--but he died from postoperative haemorrhage. The surgical specimen of the aorta showed cystic medial necrosis. This rare case emphasizes the need to consider such a diagnosis in a patient with ADPKD who presents to the emergency department with sudden cardiac arrest. In addition, the histological finding indicates the aetiological role of a collagen defect in addition to chronic hypertension in the pathogenesis of aortic dissection in ADPKD patients.     

Aortic root replacement surgery: indications,techniques and outcomes

Aortic root pathology is a common cause of aortic insufficiency. Aortic root aneurysm and aortic dissection, if left untreated, carry significant risk of mortality and morbidity. Surgical treatment involves replacement of the aortic valve, sinuses and ascending aorta. A number of prosthetic options have been developed including composite valve–synthetic graft, xenograft, homograft and pulmonary autograft. The current review describes the two main indications for aortic root replacement surgery, aortic dissection and root aneurysm, and discusses the various operative strategies and outcomes.     

Evaluation for abdominal aortic aneurysms is justified in patients with thoracic aortic aneurysms

Aortic aneurysms are a significant cause of mortality, and the presence of multiple aneurysms may affect treatment plans. The purpose of this study was to determine the frequency of abdominal aortic aneurysms (AAAs) in patients with thoracic aortic aneurysms (TAAs) and to establish whether patient specific factors, such as gender and comorbidities, influenced the frequency of AAAs, thereby indicating if and when abdominal aortic evaluation is justified. Electronic medical records were reviewed from 1000 patients with a computed tomography (CT) angiogram of the chest and abdomen and a clinical diagnosis of TAA from Cardiac Surgery clinic between 2008 and 2013. 538 patients with history of aortic intervention, dissection, rupture or trauma were excluded. The frequency of AAAs among the 462 remaining patients was established, and statistical analysis was used to elucidate differences in frequency based on age, gender, comorbidities, and TAA location. Overall, 104 of 462 (22.5 %) patients with a TAA also had an AAA. There were significant differences in the frequency of AAA based on TAA location, age, and comorbidities. The following comorbidities showed positive associations with AAA using logistic regression analysis: age ≥65 (P < 0.0001; OR 30.1; CI 7.14–126.61), smoking history (P < 0.0001; OR 4.1; 2.35–7.30), and hypertension (P = 0.024; OR 2.1; CI 1.11–4.16). Aneurysms in the proximal/mid descending (P < 0.0001; OR 4.96; CI 2.32–10.61) and diaphragm level (P < 0.0001; OR 38.4; CI 14.71–100.15) of the aorta also showed a positive association with AAAs when adjusted for age and gender. AAA screening in patients with TAA is a reasonable, evidence-based option regardless of the TAA location, with the strongest support in patients >age 55, with systemic hypertension, a smoking history and/or a TAA in the descending thoracic aorta.     

Thoracic point-of-care ultrasound is an accurate diagnostic modality for clinically significant traumatic pneumothorax

Objective

There are conflicting data regarding the accuracy of thoracic point-of-care ultrasound (POCUS) in detecting traumatic pneumothorax (PTX). The purpose of our study was to determine the accuracy of thoracic POCUS performed by emergency physicians for the detection of clinically significant PTX in blunt and penetrating trauma patients.

Methods

We conducted a retrospective institutional review board–approved study of trauma patients 15 years or older presenting to our urban Level I academic trauma center from December 2021 to June 2022. All study patients were imaged with single-view chest radiography (CXR) and thoracic POCUS. The presence or absence of PTX was determined by multidetector computed tomography (CT) or CXR and ultrasound (US) with tube thoracostomy placement.

Results

A total of 846 patients were included, with 803 (95%) sustaining blunt trauma. POCUS identified 13/15 clinically significant PTXs (defined as ≥35 mm of pleural separation on a blinded overread or placement of a tube thoracostomy prior to CT) with a sensitivity of 87% (95% confidence interval [CI] 58–97), specificity of 100% (95% CI 99–100), positive predictive value of 81% (95% CI 54%–95%), and negative predictive value of 100% (95% CI 99%–100%). The positive likelihood ratio was 484 and the negative likelihood ratio was 0.1. CXR identified eight (53%) clinically significant PTXs, with a sensitivity of 53% (95% CI 27%–78%) and a specificity of 100%, when correlated with the CT. The most common reason for a missed PTX identified on expert-blinded overread was failure to recognize a lung point sign that was present on US.

Conclusions

Thoracic POCUS accurately identifies the majority of clinically significant PTXs in both blunt and penetrating trauma patients. Common themes for false-negative thoracic US in the expert-blinded overread process identified key gaps in training to inspire US education and medical education research.     

Dissection of the proximal thoracic aorta: a new ultrasonographic sign in the subxiphoid view

Dissection of the thoracic aorta is a life-threatening event that presents with some regularity to emergency departments (EDs). Despite often nonspecific symptoms, it is critical to catch this disease process early, especially when the proximal aorta is involved because dissections involving the aortic root can lead to myocardial infarction and failure of the aortic valve resulting in death. Current imaging options include contrast-enhanced chest computed tomography (CT), angiography, magnetic resonance imaging, or transesophageal echocardiography. Although not as accurate as transesophageal echocardiography, transthoracic echocardiography (TTE) can be used to detect aortic dissection as well. We present a previously undescribed echocardiographic finding associated with proximal dissection of the thoracic aorta in 7 cases.     

主动脉缩窄合并右弓右降及多囊状动脉瘤的影像诊断

目的 研究主动脉缩窄合并右弓右降及多囊状动脉瘤的的影像学表现。方法 回顾性分析2例主动脉缩窄合并右弓右降及多囊状动脉瘤x线胸片、超声心动图、心血管造影、三维动态增强磁共振造影(3DDCEMRA)资料并与手术病理结果对照。结果 两例均为镜面右位主动脉弓(Ⅰ型)、主动脉缩窄、主动脉弓部多囊状动脉瘤。结论 心血管造影是诊断该类复杂畸形最可靠的方法，三维动态增强磁共振造影(3DDCEMRA)在一定程度上可以替代心血管造影，能为临床手术提供明确的定位与定性诊断。     

Interpretation Accuracy and Interrater Agreement of Pediatric Skin and Soft Tissue Point-of-Care Ultrasound Images among Residents and Faculty

BackgroundPoint-of-care ultrasound (POCUS) is commonly used to facilitate care in the emergency department. Acquired images are often reviewed by local experts for educational and quality assurance purposes. However, no published study has examined the accuracy and reliability of POCUS image interpretation by multiple reviewers.ObjectivesWe studied the accuracy and interrater agreement among expert and trainee reviewers of prerecorded pediatric skin and soft tissue (SST) POCUS images.MethodsPOCUS faculty and emergency medicine (EM) residents blindly reviewed deidentified pediatric SST POCUS images and indicated whether a drainable fluid collection was present, absent, or indeterminate. This was then compared with the gold standard based on discharge diagnoses and telephone follow-up. Images rated as indeterminate were excluded from the initial analysis. Sensitivity analysis assuming indeterminate answers were inaccurate was subsequently conducted.ResultsIn phase 1, 6 pediatric EM POCUS directors reviewed 168 images. The overall accuracy was 79.7% (range 66.1–86.0%). The mean Cohen's kappa was 0.58 (range 0.24–0.84). Sensitivity analysis yielded an overall accuracy of 71.3% (range 56.5–76.9%) and a Cohen's kappa of 0.43 (range 0.20–0.59). In phase 2, 6 general EM POCUS faculty and 20 EM residents reviewed 120 images. The overall accuracy among residents was 72.2% (range 51.4–84.7%) and among faculty was 83.6% (range 77.9–88.8%). Sensitivity analysis yielded an overall resident accuracy of 63.0% (range 49.5–80.7) and an overall faculty accuracy of 73.9% (range 67.0–79.8%). Fleiss' kappa was 0.322 for residents and 0.461 for faculty.ConclusionsWe found moderate accuracy and fair to good interrater agreement among POCUS faculty and EM residents reviewing pediatric SST POCUS images.     

Multidetector CT of the thoracic aorta

Recent advancement of MDCT provides high-resolution axial images with optimal contrast enhancement and 3D reformatted images of the thoracic aorta. MDCT is now playing a dominant and critical role in the evaluation of thoracic aortic disease. This article will focus on procedural considerations of MDCT: acquisition parameters, contrast injection and post-processing techniques and imaging findings of thoracic aortic diseases including, aortic dissection, intramural hematoma, penetrating atherosclerotic ulcer, aneurysm, and traumatic injury.     

腔内隔绝术治疗胸腹主动脉瘤的临床应用

目的探讨腔内隔绝术治疗胸腹主动脉瘤的疗效和安全性。方法2000年5月～2004年10月,采用腔内隔绝术治疗胸腹主动脉瘤7例,其中4例胸主动脉夹层动脉瘤、1例胸主动脉假性动脉瘤、2例肾下型腹主动脉瘤,术后随访采用彩超和增强CT检查。结果7例病人共成功置入10个支架。随访2～28个月,所有支架位置、形态正常。4例胸主动脉夹层动脉瘤的内膜破裂口封闭,胸降主动脉和腹主动脉真腔扩大,假腔内血栓形成。1例胸主动脉假性动脉瘤和2例肾下型腹主动脉瘤的瘤体缩小。2例术后出现微小内漏,分别在2个月、6个月后内漏自行封闭,1例术后出现髂外动脉夹层经PTA和Wallstent治疗。结论腔内隔绝术能有效治疗胸腹主动脉瘤,具有创伤小、疗效确切和并发症少等优点。     

Acute thoracic aortic dissection: The basics

With an increasing incidence, aortic dissection is the most common acute illness of the aorta. In the setting of chronic hypertension, with or without other risk factors for aortic dissection, this diagnosis should be considered a diagnostic possibility in patients presenting to the emergency department with acute chest or back pain. Left untreated, about 75% of patients with dissections involving the ascending aorta die within 2 weeks of an acute episode. But with successful initial therapy, the 5-year survival rate increases to 75%. Hence, timely recognition of this disease entity coupled with urgent and appropriate management is the key to a successful outcome in a majority of the patients. This article reviews acute thoracic aortic dissection, including ED diagnosis and management.