Cheng Stephen W K, Ting Albert C W, Ho Pei, Wu Lisa L H
Department of Surgery, University of Hong Kong Medical Centre, Queen Mary Hospital, China.
J Vasc Surg. 2004 Feb;39(2):409-15. doi: 10.1016/j.jvs.2003.08.031.
Radiotherapy to the head and neck often results in carotid stenosis, but the course of disease is unknown. We investigated the natural history and progression of asymptomatic carotid stenosis induced by external irradiation. Patients and methods The study included 130 carotid arteries in 95 patients who had received external radiation therapy to the head and neck area and who had asymptomatic, mild internal carotid artery or common carotid artery stenosis. Stenosis of 15% to 49% on duplex ultrasound (US) scans defined mild (<50%) disease. Another 95 arteries in 74 patients with matched degree of carotid artery stenosis but who had not received radiation therapy were used as control. Both groups were followed up prospectively with serial duplex US scanning, and degree of carotid artery stenosis was categorized as 15% to 49%, 50% to 69%, 70% to 99%, and occlusion. Progression of carotid artery stenosis was defined as increase in stenosis from less than 50% to 50% or greater at ultrasonography. Secondary end points included progression to higher disease category, new cerebrovascular symptoms, and death. Data from irradiated arteries was compared with control data with the life table method. A Cox regression model was used to analyze disease progression, adjusted for covariates of sex, age, smoking, diabetes, and hypertension.
Mean follow-up was 36 months. Adjusted freedom from progression rates at 3 years were 65% for irradiated arteries and 87% for control arteries at life-table analysis (P =.035; odds ratio, 3.1). The annualized progression rate from less than 50% to 50% or greater in irradiated arteries was 15.4%, compared with 4.8% in nonirradiated arteries. A long history of cervical irradiation (>6 years) was the only significant risk factor for disease progression. There was no difference between the two groups regarding development of new symptoms or mortality.
Carotid stenosis associated with external irradiation progresses more rapidly compared with nonirradiated atherosclerotic arteries. Aggressive surveillance is recommended.
头颈部放疗常导致颈动脉狭窄，但疾病进程尚不清楚。我们研究了外照射诱发的无症状性颈动脉狭窄的自然病史和进展情况。患者与方法 本研究纳入了95例接受过头颈部区域外照射且有无症状性轻度颈内动脉或颈总动脉狭窄的患者的130条颈动脉。双功超声（US）扫描显示狭窄15%至49%定义为轻度（<50%）病变。另外选取74例颈动脉狭窄程度匹配但未接受放疗的患者的95条动脉作为对照。两组均通过系列双功超声扫描进行前瞻性随访，颈动脉狭窄程度分为15%至49%、50%至69%、70%至99%以及闭塞。颈动脉狭窄进展定义为超声检查时狭窄程度从小于50%增加至50%或更高。次要终点包括进展至更高疾病类别、出现新的脑血管症状以及死亡。采用寿命表法将照射动脉的数据与对照数据进行比较。使用Cox回归模型分析疾病进展情况，并对性别、年龄、吸烟、糖尿病和高血压等协变量进行校正。
平均随访36个月。寿命表分析显示，3年时照射动脉校正后的无进展率为65%，对照动脉为87%（P = 0.035；比值比，3.1）。照射动脉中狭窄程度从小于50%进展至50%或更高的年化进展率为15.4%，未照射动脉为4.8%。颈部放疗史较长（>6年）是疾病进展的唯一显著危险因素。两组在出现新症状或死亡率方面无差异。
与未照射的动脉粥样硬化动脉相比，外照射相关的颈动脉狭窄进展更快。建议进行积极监测。
