Metallic stents for rescuing a patient with severe upper airway compression due to aortic aneurysm

Abstract

Aortic aneurysm is usually a potentially life-threatening medical problem, with a 5-year survival rate of 20% if there is no surgical repair. Upper airway compression due to aortic aneurysm usually presents with wheezing, coughing, hemoptysis, dyspnea, or pneumonitis. We report a 78-year-old male patient with a history of chronic obstructive pulmonary disease who was admitted to our emergency department because of wheezing dyspnea for 2 days. Acute chronic obstructive pulmonary disease exacerbation with respiratory failure was impressed, but the patient had poor response to bronchodilators and systemic steroids treatment. Because chest radiography revealed a widening of the upper mediastinum and right lower lung collapse, fiberoptic bronchoscopy was performed and revealed narrowing at the lower portion of trachea and orifice of right main bronchus. Chest computed tomography scan showed aortic aneurysm involving the aortic arch and near the entire thoracic aorta. Because of his poor condition, surgery for aortic aneurysm was not suggested by the thoracic surgeons. We deployed expandable metallic stents in the right main stem bronchi and in the distal trachea. The patient was then weaned from mechanical ventilation a few days later. Aortic aneurysm is usually a potentially life-threatening medical problem, with a 5-year survival rate of 20% if there is no surgical repair [1]. It often results from cystic medial degeneration weakening the aortic wall and seems to occur naturally with increasing age. In young adults, aortic aneurysm is often associated with Marfan syndrome or less common connective tissue disorders such as Ehlers-Danlos syndrome [2]. However, most aortic aneurysms are associated with atherosclerosis and risk factors such as hypertension, hypercholesterolemia, and smoking [3]. The clinical presentation of aortic aneurysm can be quite variable and is often related to adjacent organ compression and alteration in end-organ blood supply. Upper airway compression due to aortic aneurysm usually presents with wheezing, coughing, hemoptysis, dyspnea, or pneumonitis [4-13]. However, it was rarely presented as fatal respiratory distress [4]; and there has been no effective therapy for management of this emergent medical condition if the patient is not suitable for operation. The following report describes a patient with aortic aneurysm presenting with upper airway obstruction and respiratory failure who was successfully rescued by endobronchial expandable metallic stents. A 78-year-old man with a history of chronic obstructive pulmonary disease (COPD) was admitted because of wheezing dyspnea with respiratory distress. He had been hospitalized several times over the prior year for COPD exacerbations. On arrival at our emergency department (ED), he was drowsy, pale, and diaphoretic, and had cool extremities. There was marked respiratory distress, and his systolic blood pressure was 90 mm Hg. On auscultation of thorax, diffuse wheezing and relatively diminished breathing sounds over right side were heard. Chest radiography revealed a widening of the upper mediastinum and bilateral lung hyperinflation (Fig. 1A). Under the impression of COPD exacerbations with acute respiratory failure, he was intubated with mechanical ventilation support. However, episodic oxygen desaturation with low tidal volume occurred despite systemic steroids and bronchodilators use. Because of difficulty in passing through the suction tube, endobronchial tumor was suspected. Bronchoscopy was then performed and showed a narrowing at the lower portion of trachea and orifice of right main bronchus (Fig. 1B). For evaluation of extent of external compression to large airway, oblique-coronal chest computed tomography (CT) scan showed aortic aneurysm involving the aortic arch and near all the thoracic aorta, with high-grade lumen compression in the carina and right side main bronchus (Fig. 2A). Because of his poor condition, surgery for aortic aneurysm was not suggested by the thoracic surgeons. The patient then underwent expandable metallic airway stents under fiberoptic bronchoscopy (Fig. 2B) and was successfully weaned from mechanical ventilator. Aortic aneurysm could be divided into 2 subtypes: a true aneurysm, in which the dilated segment involves all 3 layers of the aorta, and a false or pseudoaneurysm, which is a contained hematoma outlined by adventitia or surrounding tissue [14]. In modern series, aneurysms of the ascending aorta occur most commonly (60%), followed by aneurysms of the descending aorta (40%) [15]. At least one half of patients with thoracic aortic aneurysms are asymptomatic; and the aneurysm is discovered incidentally by chest radiography, echocardiography, or CT [14,15]. The symptoms may appear as a vascular consequence of the aneurysm or a local mass effect in the late course of the disease with disease progression. Vascular consequences include aortic regurgitation from dilation of the aortic root, often associated with secondary congestive heart failure, or distal thromboembolism. An ascending or arch aneurysm may cause superior vena cava syndrome as a result of compression of the superior vena cava or innominate vein. Compression of the trachea or main stem bronchus may be a mass effect of aneurysms of the arch or descending aorta and may result in tracheal deviation, wheezing, cough, dyspnea (with symptoms that may be positional), hemoptysis, or recurrent pneumonitis [15,16]. Most aneurysms are associated with atherosclerosis and risk factors such as hypertension, hypercholesterolemia, and smoking. Rupture and acute dissection are the major complications of thoracic aortic aneurysms and can be fatal. In several case series, aneurysm rupture occurred in 32% to 68% of medically treated patients and accounted for 32% to 47% of deaths [15,16]. Concomitant cardiovascular disease is also common in those with thoracic aortic aneurysm and represents the most frequent cause of death besides aortic rupture [15,16]. Aortic aneurysms causing large airway obstruction have been reported in the medical literature, but it is a rare cause of mortality in aortic aneurysm [4,13]. In clinical practice, wheezing dyspnea often leads to the diagnosis of COPD with exacerbation in an advance-aged patient with COPD history. Recurrent exacerbations also lead to the diagnosis of COPD in progression. The information may make us order more medical treatment, such as bronchodilator use, antibiotic use, or even ventilator support. However, the case report mentioned demonstrates that wheezing dyspnea may not only be a sign of COPD but also a sign of large airway compression, especially in advance-aged patient with smoking who is in high risk for COPD, hypertension, and aortic aneurysm. About the management to thoracic aneurysm, asymptomatic aneurysms are initially managed medically; symptomatic and expanding aneurysms or those more than 55 mm in diameter in the ascending aorta or more than 60 mm regardless of site or symptoms are managed surgically. Surgical options include open surgical repair and endovascular repair. Aneurysmatic disease confined to the descending aorta can be managed by endovascular surgery [15,16]. About therapy to aortic disease-related large airway compression, surgery was the main therapy in previous case reports, including cardiopulmonary bypass, suspension of ascending aorta, shunt insertion, and aorta repair [17]. In our case, the surgeon did not suggest surgical intervention for high risk because of acute respiratory distress and multiple medical comorbidities. For rescuing the patient, we performed bronchial stent implantation as an alterative treatment. We successfully resolved the respiratory distress and saved the patient's life. Compression of the large airway attributable to benign airway disease can be difficult to treat and has traditionally required formal surgical intervention. However, this may not be a suitable option for a proportion of patients who have multiple medical comorbidities, especially in emergent condition. In a series of 31 cases of large airway obstruction secondary to benign causes, Madden et al [18] concluded that expandable metallic stents are a useful strategy to manage selected patients with large airway obstruction secondary to benign disease. At present, no large study has reviewed the role of bronchial stent in airway compression by aortic aneurysm without operation. However, we can conclude that bronchial stent implantation may be an emergent and rescuing procedure for patients with aorta disease-related airway compression who are not suitable for surgery. © 2009 Elsevier Inc. All rights reserved.