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CASE REPORT
Year : 2022 | Volume
: 32
| Issue : 4 | Page : 218-220
The utility of paraspinal acoustic windows for the evaluation of acute dissection of descending thoracic aorta in the emergency setting
Serenella Conti1, Marco Dell'Uomo1, Marcello Dominici2
1 Complex Cardiological Structure, Santa Maria Hospital of Terni, University of Perugia, Italy
2 Emergence Department, San Matteo Hospital of Spoleto, Local Health Unit Company Umbria n° 2, Italy
Correspondence Address:
Serenella Conti
Complex Cardiological Structure, Santa Maria Hospital of Terni, University of Perugia
Italy
Source of Support: None, Conflict of Interest: None
CheckDOI: 10.4103/jcecho.jcecho_35_22
Acute aortic dissection (AAD) is the prevalent acute aortic syndrome characterized by rapid onset and progression with time-dependent prognosis. When suspecting AAD of descending thoracic aorta in the context of the emergency department setting, computed tomography scanning and trans-esophageal echocardiography are the most useful imaging modalities. The sensitivity of transthoracic echocardiography in diagnosing for type B dissection is only 31%–55% when compared with other modalities. We describe the case of a 62-year-old female with a clinical history of Marfan syndrome where the low sensitivity of the transthorac approach in the detection of descending aortic dissection was overcomed by the posterior thoracic approach with the posterior paraspinal window (PPW). In the literature, are described just few reports where echocardiography via the PPW makes it possible to diagnose acute descending aortic syndrome.
Keywords: Aortic dissection, echocardiography paraspinal window, paraspinal window, posterior thoracic window, transthoracic echocardiography
Acute aortic dissection (AAD) is the prevalent acute aortic syndrome characterized by rapid onset and progression with time-dependent prognosis. When suspecting AAD of descending thoracic aorta in the context of the emergency department setting, computed tomography (CT) scanning and trans-esophageal echocardiography (TEE) are the most useful imaging modalities. The sensitivity of transthoracic echocardiography (TTE) in diagnosing for type B dissection is only 31%–55% when compared with other modalities.[1] To avoid a delay in the diagnosis, TTE is not the modality of choice in suspected acute aortic syndrome. We describe the case of a 62-year-old female with a clinical history of Marfan syndrome where the low sensitivity of the transthoracic approach in the detection of descending aortic dissection was overcomed by the posterior thoracic approach with the posterior paraspinal window (PPW). In literature, are described just two dated reports where echocardiography via the PPW makes it possible to diagnose an intramural hematoma[2] and a descending aortic dissection.[3]
Case ReportWe describe the case of a 62-year-old female with clinical history of Marfan syndrome. The patient had already received 15 year prior a Benthall procedure for acute dissection of proximal ascending aorta with severe aortic valve regurgitation. The patient had also undergone aorto-aortic bypass surgery to treat abdominal aorta aneurysm. She arrived at the emergency department in the first pandemic phase of COVID-19 complaining of severe and sudden pain localized in the left para-scapular region. The pain had appeared about 3 h prior. The patient also complained of general malaise, nausea, and vomiting. Physical examination revealed an antalgic right lateral decubitus position. Her vital signs showed hemodynamic stability with a blood pressure of 120/80 mmHg in both arms, heart rate 55 bpm, respiratory frequency 22 bpm, and body temperature 36°C. Electrocardiogram showed sinus bradycardia. She had a “pectus escavatum” and a laparocele that impeded partially the clinical evaluation. The trans-thoracic echocardiographic approach was initially used for evaluation the ascending aorta using the suprasternal notch window with severe limitation of the image quality. We then tried the para-spinal window: through this approach, even in the absence of pleural effusion, we were able to visualize in the long axis the descending thoracic aorta which appeared aneurismatic with a dissection flap and a tear with flow between the true and false lumen as seen on the color flow imaging [Figure 1]. The tear seems to be at the level of diaphragm with retrograde dissection to descendent thoracic not involving the left subclavian artery and the distal aortic arch aort. We were also able to visualize partial thrombosis in the false lumen [Figure 2].
Figure 1: Color Doppler image from the left paraspinal long-axis window on the descending thoracic aorta: the white arrow shows the aneurysmal lumen with the intimal opening that allows retrograde dissection (white star)
Figure 2: B-mode image from the left paraspinal long-axis window on the descending thoracic aorta: the white arrow shows the true lumen; the big red arrow shows the false light; the red star shows the intimal flap; the white arrow shows partial thrombosis of the false lumenA CT scan was then performed and a Stanford type B lesion was described with the expansion of both the thoracic descending aorta and abdominal aorta [Figure 3]. The patient was referred by an hour for hospital access to the Hub Hospital for the evaluation and treatment by a vascular surgeon.
Figure 3: Angio computed tomography scan of the aorta with evidence of descending aorta dissection Discussion AAD is a life-threatening syndrome in which an intimal tear in the aortic wall allows passage of blood into a “false” channel that forms between the intima and the media. When suspecting AAD of descending thoracic in the context of the emergency department setting CT scanning and TEE are the most useful imaging modalities. Multiple studies showed that the sensitivity of TEE for diagnosing AD was 86% ~ 100%, the specificity could be up to 77% ~ 100%.[1] However, since patients with AD are in critical condition and TEE is a semi-invasive procedure, TEE evaluation of AD patients is generally performed under anesthesia.[2] TTE permits adequate assessment of several aortic segments, particularly the aortic root and proximal ascending aorta and, in most cases, the aortic arch, proximal descending aorta, and abdominal aorta. On TTE, the descending thoracic aorta is seen via the parasternal window, suprasternal notch approach and through the apical and subcostal windows. It is described in the literature[3],[4] that in patients with a left pleural effusion, images of the descending aorta may also be obtained using the acoustic window that forms through fluid using a left posterior chest (paraspinal) approach with the patient in a right lateral decubitus position. The major limitations of the trans-thoracic approach to ultrasound evaluation of the aorta are acoustic access and image quality.[5]
ConclusionOne of the major challenges in improving the diagnosis of AAD is to have the clinical suspicion. In this case although the AAD is more frequent in men, clinical history of Marfan syndrome and the posterior location of chest pain helped us to look for it. TTE is an indispensable tool for a rapid clinical evaluation of AAD in the emergency department. TTE can clearly visualize internal flaps and intimal tears, but it is more useful when the flap is located in the aortic root, while subtype B is frequently missed. The severe limitation in the suprasternal notch window obligated us to explore the paraspinal window with an unaspected ability to confirm our clinical suspicion. In this case, the lung was displaced by a tortuous descending aortic aneurysm and the echo imaging from the paraspinal window became the window of choice. This is a clinical case where a clever use of a usually neglected transthoracic acoustic window[6],[7] and should be a more widespread method, because it allows a fast echo approach in the emergency room setting.[8] The peculiarity of this case is also the possibility of exploring the descending thoracic aortic even in the absence of a pleural effusion.
The hemodynamic stable condition of patients permitted us to perform the aortic multi-slice spiral CT angiography which improved diagnostic accuracy in terms of detailed extension of dissection.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
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Conflicts of interest
There are no conflicts of interest.
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