Upper Airway Obstruction in an Adult: An Unusual Presentation—Dissection of the Cervical Aortic Arch

CASE REPORT

A 46-year-old morbidly obese woman (BMI—64 kg/m²; grade 3) presented to an emergency department of a district hospital with acute shortness of breath that rapidly progressed to cardiorespiratory arrest. Following a brief period of CPR as per ACLS protocol, she was revived. Empirically she was diagnosed as community-acquired pneumonia and was subsequently transferred to our intensive care unit for ongoing management.

Her background history includes intellectual impairment and depression. She was never intubated or anesthetized prior to this presentation.

In ICU, she was sedated and ventilated. Chest X-ray was unremarkable except for mild basal consolidation. Over the next 5 days, she was weaned off the ventilator and was successfully extubated electively onto non-invasive ventilation (NIV). The immediate postextubation period was unremarkable, she was sitting in a chair, conversing appropriately with the staff and weaned from NIV to high-flow oxygen.

About 7 hours after extubation, she wanted to rest in bed and the head end of her bed was made flat. Shortly after this, she developed cyanosis, tachycardia, and hypertension, and an emergency call was initiated. A clinical diagnosis of upper airway obstruction was made. She was extremely difficult to ventilate and oxygenate with bag-valve mask, external positive end-expiratory pressure (PEEP), airway maneuvers, and airway adjuncts including a laryngeal mask. Hence, she was emergently intubated using a video laryngoscope by the intensivist. Postintubation arterial blood gas showed profound hypercarbia confirming a period of inadequate ventilation.

Given the clinical diagnosis of airway obstruction, an urgent CT scan of the neck and chest was performed to identify the cause. That CT demonstrated an anomalous cervical aortic arch. Given the unusual anatomy—transthoracic echocardiography was performed demonstrating a dissection flap in the arch. The aortic valve and ascending aorta were normal (type B Stanford classification). Subsequent CT angiogram (Fig. 1) and 3D CT reconstruction of the arch along with its branches revealed multiple anomalies of the branches (Figs. 2 and 3) and a large type-B dissection of the aorta (Fig. 4). This demonstrated a near-total obstruction of the thoracic inlet with associated compression of the esophagus and trachea (Fig. 5).

Abnormalities include an aortic arch at the level of the C3 to C4 vertebrae (normal T2–T4) an anomalous left internal carotid originating from the right innominate artery crossing the trachea anteriorly from right to left and the arch itself behind the esophagus, thereby compressing the trachea and esophagus from behind (Fig. 3). A proximal dissection flap was identified in the arch and an extensive intramural hematoma was identified extending into the left common iliac artery (Fig. 4). There was no extension of the dissection into the carotid arteries.

Patient recovered well from the period of hypoxia, neurologically appropriate. She was transferred, still intubated, and ventilated, to another higher facility for an assessment by the multidisciplinary complex airway team. After extensive discussions, the patient was deemed inoperable and was extubated and palliated.