Irvine C D, Cole S E, Foley P X, Brookes S T, Morgan M, Wilson Y, Hayward J, Baird R N, Lamont P M
Department of Surgery, Bristol Royal Infirmary, U.K.
Eur J Vasc Endovasc Surg. 1998 Sep;16(3):245-53. doi: 10.1016/s1078-5884(98)80227-x.
The efficacy of carotid endarterectomy (CEA) in symptomatic patients with > 70% stenosis is accepted. The stroke risk of asymptomatic patients may not justify surgical intervention. The aim of this study is to use natural history data from a single unit to identify asymptomatic patients who would benefit from CEA.
Five hundred and sixty-four patients attending for duplex ultrasound assessment of the internal carotid artery between 1986 and 1993 were retrospectively identified as focally asymptomatic with > 40% ipsilateral stenosis. Patients were traced using hospital records, family practitioner databases and the Office of Population of Census and Surveys. The number of strokes, transient ischaemic attacks and cause of death were determined. Exclusions were 15 (2.7%) asymptomatic occlusions and 49 patients (8.7%) who underwent surgery for asymptomatic disease.
Thirteen patients (2.6%) were not traced, leaving 487 study patients. The average follow-up was 41 months (range, 1-120 months). Mean presentation age was 69 years (S.D. 8.9), and the male to female ratio was 3:2. One hundred and fifty-six (32%) patients died. Forty-three patients suffered strokes, of whom two had bilateral strokes. In total there were 16 (i/p) strokes, 25 (c/l) strokes and four strokes undetermined. The average yearly stroke rate was 2.74 per 100 person years and the (i/p) rate 1.02 per hundred person years. There was no effect of age, sex or degree of stenosis on stroke. The presence of bilateral disease did increase the risk of stroke (rel risk 2.35, p = 0.029) but not ipsilateral stroke (rel risk 1.6, p = 0.39). Patients with unilateral asymptomatic carotid disease had an all stroke rate of less than 5% in the first year after presentation and this was unaffected by degree of stenosis. In patients with bilateral disease the stroke rate in the first year after presentation increased with degree of stenosis to a stroke rate of 9.6 per 100 person years in patients with > 90% contralateral stenosis.
This data suggests that CEA will not benefit patients with unilateral asymptomatic disease. Patients with bilateral disease warrant inclusion in clinical trials.
有症状且颈动脉狭窄超过70%的患者接受颈动脉内膜切除术（CEA）的疗效已得到认可。无症状患者的中风风险可能无法证明手术干预的合理性。本研究的目的是利用来自单一机构的自然病史数据，确定能从CEA中获益的无症状患者。
回顾性确定1986年至1993年间因接受颈内动脉双功超声评估而就诊的564例患者为局部无症状且同侧狭窄超过40%。通过医院记录、家庭医生数据库以及人口普查和调查办公室对患者进行追踪。确定中风、短暂性脑缺血发作的数量以及死亡原因。排除15例（2.7%）无症状闭塞患者和49例（8.7%）因无症状疾病接受手术的患者。
13例患者（2.6%）未被追踪到，剩余487例研究患者。平均随访时间为41个月（范围1 - 120个月）。平均就诊年龄为69岁（标准差8.9），男女比例为3:2。156例（32%）患者死亡。43例患者发生中风，其中2例为双侧中风。总共发生16例同侧中风、25例对侧中风以及4例中风情况未确定。平均每年中风发生率为每100人年2.74例，同侧中风发生率为每100人年1.02例。年龄、性别或狭窄程度对中风无影响。双侧病变的存在确实增加了中风风险（相对风险2.35，p = 0.029），但同侧中风风险未增加（相对风险1.6，p = 0.39）。单侧无症状颈动脉疾病患者在就诊后第一年的总中风发生率低于5%，且不受狭窄程度影响。在双侧病变患者中，就诊后第一年的中风发生率随狭窄程度增加，对侧狭窄超过90%的患者中风发生率达到每100人年9.6例。
这些数据表明CEA对单侧无症状疾病患者无益处。双侧病变患者应纳入临床试验。
