Carotid artery disease in patients with head and neck carcinoma. Irradiation has been shown experimentally to cause accelerated development of atherosclerosis in exposed large arteries. However, occurrence of such an entity in carotid arteries of patients after treatment for head and neck carcinoma is unknown. Therefore, we reviewed 179 patient charts who had undergone head and neck operations with or without irradiation between 1979-1987. Of these 179 patients, 107 (59.8%) were dead at time of follow-up. Cause of death was unknown in 42 (40%) patients; in the remainder included: respiratory arrest--33; carcinoma-related--18; cardiac--6;pneumonia--7; and trauma--1. Average interval from treatment to death was 23.5 months. Of the 72 patients known to be alive, follow-up was obtained in 52 patients. Their average age was 64.9 years. Risk factors for atherosclerosis included: male gender--43; smoking--50; hypertension--9; diabetes--4; coronary artery disease--12; and peripheral vascular disease--4. Seventy-five per cent of these patients received postoperative irradiation. Average follow-up was 64.5 months. Duplex scans were performed on 34 patients. Three patients had common or internal carotid stenoses greater than 75 per cent. All of these patients had received irradiation and none of them were symptomatic. Seven patients had carotid stenoses between 50 to 75 per cent; five of these had received irradiation. Of these five patients, one had a stroke 60 months postoperatively, and one had a TIA 36 months postoperatively. The remaining 58 patients (of which 48 had irradiation) had carotid stenoses less than 50 per cent and none were symptomatic. 