Medical Image of the Month: Double Aortic Arch

Figure 1. A chest radiograph performed after endotracheal intubation of the patient demonstrated prominence of the upper mediastinum in the region of the right paratracheal strip (red arrow).

Figure 2. A non-contrasted CT of the chest demonstrates a complete vascular ring secondary to the patient’s double aortic arch (outlined in red) surrounding the trachea (T) and esophagus (E).

Case Presentation: A 78-year-old gentleman presented to the hospital via EMS with altered mental status. An urgent CT of the head performed in the emergency room demonstrated a large, right intraparenchymal hemorrhage with intraventricular extension into the right lateral ventricle. His Glascow Coma Scale score was 6, and he was intubated for airway protection.  A chest radiograph performed to verify placement of the endotracheal tube demonstrated prominence of the upper mediastinum in the region of the right paratracheal strip (Figure 1). A CT of the chest (Figure 2) demonstrated a double aortic arch corresponding to the upper mediastinal abnormality noted on the chest radiograph. In speaking with the patient’s family after acquiring the CT of the chest, they stated that the patient had long-term issues with dysphagia – specifically choking with solid foods. Unfortunately, the patient passed away from complications of his large intraparenchymal hemorrhage.

A double aortic arch results from persistence of both the right and left embryonic arches with each arch giving rise to the ipsilateral, separate carotid and subclavian arteries (1). A double aortic arch is the most common cause of a symptomatic vascular ring with the trachea and esophagus being compressed by the two arches (1). Symptoms usually arise in childhood with good outcomes with surgical repair of this abnormality in pediatric populations. A few case series exist describing repair of this anomaly in adult populations (2).

Kelly Wickstrom DO, Steven P. Sears DO, and Laura Meinke MD

Division of Pulmonary, Critical Care, Allergy and Sleep Medicine

University of Arizona College of Medicine

Tucson, AZ USA

References

1. Hanneman K, Newman B, Chan F. Congenital variants and anomalies of the aortic arch. Radiographics. 2017 Jan-Feb;37(1):32-51. [CrossRef] [PubMed]
2. Noguchi K, Hori D, Nomura Y, Tanaka H. Double aortic arch in an adult. Interact Cardiovasc Thorac Surg. 2012 Jun;14(6):900-2. [CrossRef] [PubMed]

Cite as: Wickstrom K, Sears SP, Meinke L. Medical image of the month: Double aortic arch. Southwest J Pulm Crit Care. 2019;18(5):120-1. doi: https://doi.org/10.13175/swjpcc019-19 PDF 

Medical Image of the Week: Fibrosing Mediastinitis

Figure 1. Panel A: Thoracic CT showing airway occlusion (arrowhead) from fibrosing mediastinitis. Panel B: pulmonary artery obstruction (arrow) from fibrosing mediastinitis.

Histoplasmosis is endemic to the Midwest US and commonly causes an acute infection that presents as a subacute pneumonia. Chronic sequelae of histoplasmosis range from asymptomatic nodules to debilitating fibrosing mediastinitis (1). Mediastinal fibrosis represents exuberant scarring in response to histoplasmosis infection. Fibrosis may occlude airways (Figure 1A, arrow head) obstruct pulmonary arteries (figure 1B, arrow) or veins and impinge upon the esophagus and other vital structures residing in the mediastinum. Chest imaging shows subcarinal or mediastinal widening. CT scans may reveal fibrotic encasing of mediastinal structures and calcification of regional lymph nodes. Recurrent and often serious hemoptysis results from lung or airway damage and vascular compromise. Respiratory failure can occur. Treatment rarely includes stenting of airways or surgery (2). Vascular stenting may be indicated in some cases. Regardless, these difficult cases must be referred to centers with experience in histoplasmosis related complications.

¹Kenneth S. Knox, MD and ²Veronica A. Arteaga, MD

¹University of Arizona College of Medicine- Phoenix

²University of Arizona College of Medicine- Tucson

References

1. Peikert T, Colby TV, Midthun DE, Pairolero PC, Edell ES, Schroeder DR, Specks U.Fibrosing mediastinitis: clinical presentation, therapeutic outcomes, and adaptive immune response. Medicine (Baltimore). 2011 Nov;90(6):412-23. [CrossRef] [PubMed]
2. Hammoud ZT, Rose AS, Hage CA, Knox KS, Rieger K, Kesler KA. Surgical management of pulmonary and mediastinal sequelae of histoplasmosis: a challenging spectrum. Ann Thorac Surg. 2009 Aug;88(2):399-403. [CrossRef] [PubMed] 

Cite as: Knox KS, Arteaga VA. Medical image of the week: fibrosing mediastinitis. Southwest J Pulm Crit Care. 2017;14(2):85. doi: https://doi.org/10.13175/swjpcc015-17 PDF 

Medical Image of the Week: Wide Mediastinum Due to Lung Infiltrates

Figure 1. Panel A: Admission chest x-ray showing an apparent widened mediastinum. Panels B & C: CT scan showing consolidation in the posterior lungs bilaterally. Panel D: Chest x-ray showing resolution of his widened mediastinum with an increase in positive end-expiratory pressure.

The patient is a 65-year-old man patient with a past medical history of poorly controlled hypertension and coronary artery disease who was admitted after a witnessed code arrest. He was found down, and paramedics arrived within 5 minutes and started chest compressions. His initial CXR showed a wide mediastinum (Figure 1A) that was concerning for possible aortic dissection especially with his history of poorly controlled hypertension. Due to his hemodynamic instability a chest CT scan couldn’t be done initially, but the patient underwent a trans-esophageal echo that was negative for aortic dissection.

When the patient became more stable a chest CT scan with contrast was done and showed consolidation of the medial parts of both lungs with 7 bilateral rib fractures (Figure 1 B & C). The impression was either lung contusion from the aggressive chest compression as evidenced by the bilateral 7 rib fractures or aspiration in the dependent parts of the lung. His apparent widened mediastinum resolved with increasing the positive end-expiratory pressure (PEEP) on the ventilator within 48 hours (Figure 1D).

Huthayfa Ateeli MBBS, Laila Abu Zaid MD

Department of Medicine

University of Arizona

Tucson, AZ.

References

1. Cohn SM. Pulmonary contusion: review of the clinical entity. J Trauma. 1997;42(5):973-9. [CrossRef] [PubMed]
2. Lai CC, Wang CY, Lin HI, Wang JY. Pulmonary contusion associated with chest compressions. Resuscitation. 2010;81(1):133. [CrossRef] [PubMed]

Reference as: Ateeli H, Zaid LA. Medical image of the week: widen mediastinum due to lung infiltrates. Southwest J Pulm Crit Care. 2015;10(2):77-8. doi: http://dx.doi.org/10.13175/swjpcc007-15 PDF