From the Department of Neurology, Austin Health, Heidelberg, Australia (F.C.N., B.C., B.C., V.T.).
Department of Medicine, University of Melbourne, Australia (B.C.).
Stroke. 2018 Oct;49(10):2512-2515. doi: 10.1161/STROKEAHA.118.021631.
Background and Purpose- Impaired microvascular reperfusion despite complete recanalization (no-reflow) represents a potential therapeutic target to improve outcomes after recanalization therapies. Although well documented in animal models, this phenomenon has not been demonstrated clinically. We investigated whether transcranial Doppler can detect acute microvascular changes postrecanalization as a biomarker of the no-reflow phenomenon in stroke patients. Methods- Consecutive patients with recanalized (Thrombolysis in Cerebral Infarction grade IIb/III) acute middle cerebral artery occlusion by thrombectomy at a Comprehensive Stroke Centre with a high-volume neurovascular laboratory were retrospectively identified. Sonographic measures of middle cerebral artery territory microvascular resistance (pulsatility index and resistive index) on days 1 to 3 follow-up transcranial Doppler were compared between patients and age/gender-matched controls. Results- In 53 patients, middle cerebral artery pulsatility index was significantly more likely to be asymmetrically increased on interside comparison (27.9% versus 4.9%; P=0.007) and abnormally elevated beyond normal reference ranges (46.7% versus 22.0%; P=0.016) in the symptomatic hemisphere. Middle cerebral artery pulsatility index elevation was associated with less hemorrhagic infarction (9.5% versus 45.8%; P=0.009) but worse functional outcome irrespective of infarct volume as assessed on 90-day modified Rankin Scale (score of ≤1, 18.2% versus 58.1%; P=0.035). Conclusions- Elevated microvascular resistance within the ischemic territory is commonly present after successful recanalization as measured by pulsatility index on transcranial Doppler and may be a readily available and clinically relevant biomarker of the no-reflow phenomenon.
背景与目的- 尽管完全再通（无再流），但微血管再灌注受损仍代表了再通治疗后改善预后的潜在治疗靶点。尽管在动物模型中得到了充分的证明，但这一现象在临床上尚未得到证实。我们研究了经颅多普勒是否可以检测再通后急性微血管变化，作为中风患者无再流现象的生物标志物。
方法- 在一家综合卒中中心，我们回顾性地确定了连续接受经皮机械血栓切除术治疗的再通（血栓切除术治疗脑梗死分级 IIb/III）急性大脑中动脉闭塞的患者。在第 1 至 3 天的经颅多普勒随访中，比较了患者和年龄/性别匹配的对照组大脑中动脉区域微血管阻力（搏动指数和阻力指数）的超声测量值。
结果- 在 53 例患者中，与无症状侧相比，症状侧大脑中动脉搏动指数更可能出现不对称性升高（27.9%对 4.9%；P=0.007），并超出正常参考范围（46.7%对 22.0%；P=0.016）。大脑中动脉搏动指数升高与较少的出血性梗死（9.5%对 45.8%；P=0.009）相关，但与梗死体积无关，90 天改良 Rankin 量表评分（≤1 分，18.2%对 58.1%；P=0.035）预后较差。
结论- 成功再通后，通过经颅多普勒测量搏动指数，缺血区域的微血管阻力普遍升高，这可能是无再流现象的一种易于获得且具有临床相关性的生物标志物。
