A 63 year old man was referred with a history of transient right upper limb weakness, which recovered within two hours. A previous duplex scan showed total occlusion of right internal carotid artery with a 70% stenosis of left common carotid artery. He had received radiation therapy for tonsillitis 45 years earlier. No details of previous procedure were available. He had no previous neurologic symptoms. Considering the fact that surgery would be difficult and possibly hazardous, we offered him an Endovascular treatment.

An angiography done via the femoral artery route confirmed occlusion of the right internal carotid artery. There was a stenosis with luminal irregularity of the left common carotid artery (Fig. 1). The left external carotid artery was occluded.

Fig. 1 : Angiography shows post-irradiation carotid stenosis

We performed angioplasty with stenting, using a cerebral protection filter. The filter wire was passed across the lesion, into the internal carotid artery and the filter opened (Filter Wire EZ, Boston Scientific Corporation).

A 9 x 40 mm self-expanding Wallstent (Boston Scientific Corporation) was placed in the Common carotid artery, extending into the Internal Carotid artery. Post stenting balloon angioplasty was performed. Apart from transient bradycardia, the procedure was uneventful. Post angioplasty completion angiography showed a satisfactory anatomical result (Fig. 2). Postoperatively, no complications were encountered. On eight-month follow up, he is symptom free and the last Doppler evaluation showed no evidence of restenosis.

Radiation arteritis may present in three different patterns related to the time interval since irradiation.1 Early lesions with mural thrombus formation present within 5 years of irradiation. Intermediate lesions present with mural fibrosis and occlusion without any collaterals, within 10 years of irradiation. Late lesions present as periarterial fibrosis, often 15-20 years after irradiation. Our patient presented 45 years after irradiation.

Fig. 2 : Post angioplasty check angiogram shows good flow without residual stenosis

Cervical irradiation for head and neck cancers may predispose the carotid arteries to radiation arteritis. There is a higher incidence of neurologic symptoms in patients with radiation associated carotid stenosis.2 A common pattern is involvement of the common carotid artery in absence of significant internal carotid artery disease.3 This differentiates the radiation stenosis from atherosclerotic stenosis.

Carotid revascularisation is recommended as radiation associated carotid stenosis appears to be more prone to progression and causes more neurologic symptoms than other carotid stenosis.2 Due to periarterial fibrosis, operative carotid exposure is difficult and associated with an increased risk of cranial nerve injury. Occasionally, there is obliteration of the normal endarterectomy plane by fibrosis. Hence, carotid artery stenting has been used successfully for the treatment of irradiation carotid stenosis.4,5 It offers the advantages of avoiding a difficult dissection and potential cranial nerve injuries.

Radiation induced carotid artery disease may often be bilateral. Endovascular repair has been performed previously for bilateral carotid artery stenosis.6

In conclusion, we emphasize on a detailed clinical history and a high degree of clinical suspicion to diagnose this rare condition. Carotid angioplasty appears to be a favourable alternative modality for management but long-term data are required to prove its superiority.

1. Radiation induced carotid stenosis may present in three different patterns related to time interval. The late presentation is its commonest manifestation.
2. Involvement of common carotid artery without significant disease in internal carotid artery differentiates this condition from atherosclerotic disease.
3. Peri arterial fibrosis renders surgical treatment difficult and occasionally hazardous.
4. Endovascular management appears to be an attractive, safe and efficient treatment option for radiation-induced stenosis.