Background. Patients with isolated cervical carotid artery occlusion not eligible to recanalization therapies but with compromised intracranial hemodynamics may be at risk of further clinical events. Apart from lying flat until spontaneous recanalization or adjustment of the collateral circulation hopefully occurs, no specific treatment is currently implemented. Improving collateral flow is an attractive option in this setting. Lower body positive pressure (LBPP) is known to result in rapid venous blood shift from the lower to the upper body part, in turn improving cardiac preload and output, and is routinely used in acute hemorrhagic shock. We report here cerebral blood flow velocities measured during LBPP in this patient population.

Methods. This is a retrospective analysis of the clinical, physiological and transcranial Doppler (TCD) monitoring data collected during and 15min after LBPP in 21 consecutive patients (10 females, median age: 54yrs) with recently symptomatic isolated carotid occlusion/tight stenosis (unilateral in 18) mostly due to atherosclerosis or dissection. LBPP was applied during 90min at a median 5 days after symptom onset.

Results. At baseline, middle-cerebral artery (MCA) velocities were markedly lower on the symptomatic, as compared to asymptomatic, side. LBPP significantly improved blood flow velocities in both the symptomatic and asymptomatic MCA as well as the basilar artery, which persisted 15 min after discontinuing the procedure. LBPP also resulted in mild but significant increases in mean arterial blood pressure.

Conclusions. LBPP improved intracranial hemodynamics downstream recently symptomatic carotid occlusion/tight stenosis as well as in the contralateral and posterior circulations, which persisted after LBPP deflation. Randomized trials should determine if this easy-to-use, non-invasive, non-pharmacologic approach has long-lasting benefits on the intracranial circulation and improves functional outcome.

背景。孤立性颈动脉闭塞不适合再通治疗但颅内血流动力学受损的患者可能面临进一步临床事件的风险。除了平躺直到有希望发生自发再通或侧支循环调整外，目前没有实施特定治疗。在这种情况下，改善侧支流量是一个有吸引力的选择。众所周知，下半身正压 (LBPP) 会导致静脉血从下半身快速转移到上半身，从而改善心脏前负荷和输出量，并常规用于急性失血性休克。我们在此报告该患者群体在 LBPP 期间测量的脑血流速度。

方法。这是对最近出现症状的孤立性颈动脉闭塞/狭窄狭窄（18 ) 主要是由于动脉粥样硬化或夹层。LBPP 在症状出现后的中位 5 天时在 90 分钟内应用。

结果。在基线时，与无症状侧相比，有症状侧的大脑中动脉 (MCA) 速度显着降低。LBPP 显着改善有症状和无症状的 MCA 以及基底动脉的血流速度，在停止手术后持续 15 分钟。LBPP 还导致平均动脉血压轻度但显着升高。

结论。LBPP 改善了最近有症状的颈动脉闭塞/狭窄狭窄下游以及对侧和后循环的颅内血流动力学，这种情况在 LBPP 通缩后持续存在。随机试验应确定这种易于使用、无创、非药物的方法是否对颅内循环具有持久的益处并改善功能结果。