Left Subclavian Pseudoaneurysm: A Case of Palsies in the Recurrent Laryngeal Nerve,Phrenic Nerve,and Brachial Plexus

A woman in her early 70s undergoing treatment for metastatic breast cancer was noted to have a left upper extremity deep vein thrombosis. Oral anticoagulant treatment was initiated before the patient underwent placement of a subclavian artery catheter. Upon awakening from surgery, the patient noted a change in her voice that improved slightly in the weeks following the procedure. Unfortunately, no one investigated her voice change following the procedure.

Two months after her surgery, the patient was involved in a minor motor vehicle accident, and she presented to the emergency department with acute-onset numbness and paresthesia in her left arm along with weakness in arm abduction and flexion. The hoarseness she experienced following placement of the port also reemerged. Chest radiographs showed an elevated left hemidiaphragm (see Figure 1), suggesting phrenic nerve palsy. Images from a CT of the chest and neck are presented below (see Figures 2 and 3). These images demonstrate a pseudoaneurysm continuous with the superior and anterior margin of the left subclavian artery measuring approximately 2.7 × 3.0 × 5.6 cm. This appears just lateral to the brachiocephalic trunk, and it extends superior into the margin of the C6 transverse process. Mass effect and dilatation of the pseudoaneurysm secondary to stress-induced hypertension following the patient’s wreck likely caused her upper extremity weakness and paresthesia because of compression of the superior brachial plexus. Given the shared C3-5 roots of origin of the brachial plexus and phrenic nerves and the proximity of the left recurrent laryngeal nerve (RLN) to the subclavian artery, the etiology of the patient’s multiple palsies is apparent.

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Figure 1.

Upright anteroposterior (AP) chest X-ray obtained in emergency department reveals elevation of the left hemidiaphragm.

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Figure 2.

Coronal CT of head and neck demonstrates a left subclavian pseudoaneurysm (green arrow).

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Figure 3.

Axial CT of neck reveals a left subclavian pseudoaneurysm (green arrow).

Although pseudoaneurysm is a known risk of catheters, this particular presentation with accompanied nerve compression(s) is peculiar. To correct this condition, the patient underwent surgical stenting of the aneurysm, which was reduced from 36 to 28 mm. Her upper extremity symptoms abated, but her left hemidiaphragm elevation and vocal changes persisted.

Follow-up with ENT was made to mitigate the patient’s condition. The patient demonstrated dysphonia with a whisper-like deep voice, expressed vocal fatigue, and dysphagia to liquids. She noted no worsening of her symptoms following the stenting of her pseudoaneurysm. Laryngoscopy revealed left vocal fold paralysis with incomplete glottic closure.

Although the most common causes of vocal paralysis are iatrogenic RLN injury and tumor invasion, vascular etiology should be considered. The cardiovocal (Ortner’s) syndrome of RLN palsy secondary to left atrial enlargement has sometimes also been extended to aortic aneurysmal disease. This is the first report of vocal paralysis due to subclavian pseudoaneurysm in the English literature.^1-3

Recovering the voice in vocal paralysis is accomplished by repositioning the paralyzed vocal fold so that the mobile vocal fold can easily close against it to phonate and to seal the larynx during swallowing. This can be executed soon after RLN injury by injection laryngoplasty whereby one of a variety of commercial gels, collagen, or fat is injected into the paraglottic space. This allows the patient time to heal from an injury and still have a serviceable voice. It can even be done bedside in the hospital or intensive care unit. In this particular patient, 9 months out from her injury at the time of presentation to laryngology, a more precise and permanent solution is moving directly to medialization laryngoplasty. Arytenoid adduction can be added to medialize the arytenoid’s vocal process in cases where it has come to rest in a very lateral/open position. ⁴

This case highlights the importance of educating medical and surgical colleagues regarding the importance of laryngoscopy when voice changes do not completely resolve in 2 to 3 weeks. If her persistent voice changes had been investigated early on, it is likely that the vocal fold would have been identified as weak, leading to radiographic identification of the pseudoaneurysm. This may have prevented the change after the car accident and helped to maintain her quality of life. Application of the principles in the American Academy of Otolaryngology’s Hoarseness Clinical Practice Guideline ⁵ certainly apply in this case.