Radiation-induced carotid artery stenosis.

A 78-year-old man presented with a medical history significant for squamous cell carcinoma involving the fight auricle and ipsilateral cervical metastases. He was first diagnosed in 1983 and had been treated with primary radiotherapy: 7,000 rads to the right neck, 5,400 rads to the right supraclavicular fossa, and 6,600 rads to the ear and upper neck. In 2001, he suffered a right hemispheric stroke. Carotid duplex ultrasonography at that time revealed a 70 to 80% stenosis of the right internal carotid artery (figure). Repeat ultrasonography in 2004 revealed that the artery was completely occluded. The patient underwent an uneventful en bloc resection of the tumor. Reconstruction was performed with a microvascular free-tissue transfer using the ipsilateral facial vessels. He remains disease-free 2 years later.

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The reported incidence of radiation-induced carotid artery stenosis ranges from 30 to 50%. (1,2) The presence of this complication must be considered when planning salvage surgery with microvascular reconstruction. In addition, radiation-induced carotid artery stenosis increases the risk of stroke, especially in patients with comorbid conditions such as hypertension, smoking, diabetes, and obesity. (1) The diagnosis of radiation-induced carotid artery stenosis is suggested by three criteria: (1) a history of radiation to the neck, (2) no evidence of contralateral stenosis, and (3) a longer than usual stenotic segment.

Treatments for radiation-induced carotid artery stenosis include endarterectomy and stenting. Houdart et al reported that carotid artery stenting is preferable to endarterectomy when surgical risks are high. (2) These risks are attributable to the fibrosis and scarring secondary to the radiation and/or to previous neck dissection.

While all irradiated patients are at risk for developing radiation-induced carotid artery stenosis, those who are radiated for advanced laryngeal or nasopharyngeal carcinoma should be followed more closely for this complication. Routine screening of high-risk patients with duplex ultrasonography may be warranted.

References

(1.) Abayomi OK. Neck irradiation, carotid injury and its consequences. Oral Oncol 2004;40:872-8.

(2.) Houdart E, Mounayer C, Chapot R, et al. Carotid stenting for radiation-induced stenoses: A report of 7 cases. Stroke 2001;32: 118-21.

Suggested reading

Cheng SW, Wu LL, Ting AC, et al. Irradiation-induced extracranial carotid stenosis in patients with head and neck malignancies. Am J Surg 1999;178:323-8.

Sofia Avitia, MD; Jason Hamilton, MD; Ryan F. Osborne, MD, FACS 

From the Osborne Head and Neck Institute (Dr. Avitia, Dr. Hamilton, and Dr. Osborne) and the Head and Neck Cancer Center, Cedars-Sinai Medical Center (Dr. Osborne), Los Angeles.