Nitahara K, Dan K
Department of Anesthesiology, School of Medicine, Fukuoka University, Japan.
Reg Anesth Pain Med. 1998 Nov-Dec;23(6):600-4. doi: 10.1016/s1098-7339(98)90088-8.
Stellate ganglion block (SGB) leads to vasodilation of the head and neck, as a result of a regional sympathetic blockade. However, in such cases, controversy remains concerning changes in cerebral and extracerebral blood flow in the head. We estimated the effect of SGB on blood flow in the head by measuring the blood flow velocity in cervical vessels, using magnetic resonance imaging and the direct bolus tracking method. This noninvasive method is free from potential artifacts of bones and other connective tissues.
Seven adult patients with acute or chronic pain in the head or neck underwent SGBs, using an anterior paratracheal approach with 6-8 mL of 1% mepivacaine (3 right and 4 left SGBs). Blood flow velocity in common carotid and vertebral arteries (CCA and VA) was measured simultaneously before and after SGB, using the direct bolus tracking method.
On the side of SGB, blood flow velocity in CCA significantly increased (P < .002), whereas velocity in VA was unchanged after SGB. On the side contralateral to the SGB, significant changes in blood flow velocity in CCA and VA were never observed.
Blood from the VA flows primarily to cerebral vessels, whereas that from CCA goes to both cerebral and extracerebral vessels. Given the presumed differences in blood flow distribution through the VA and CCA, we assume that the observed CCA blood flow increases, ipsilateral to the SGB, primarily as a result of vasodilation of extracerebral vessels and independent of changes in brain blood flow.
星状神经节阻滞（SGB）可导致头颈部血管扩张，这是局部交感神经阻滞的结果。然而，在这种情况下，关于头部脑内和脑外血流的变化仍存在争议。我们通过使用磁共振成像和直接团注追踪法测量颈血管中的血流速度，来评估SGB对头部血流的影响。这种非侵入性方法不存在骨骼和其他结缔组织的潜在伪影。
7例患有急性或慢性头颈部疼痛的成年患者接受了SGB，采用气管旁前路，注射6 - 8毫升1%甲哌卡因（3例右侧和4例左侧SGB）。使用直接团注追踪法在SGB前后同时测量颈总动脉和椎动脉（CCA和VA）的血流速度。
在SGB侧，CCA的血流速度显著增加（P < .002），而SGB后VA的血流速度未改变。在SGB对侧，从未观察到CCA和VA的血流速度有显著变化。
来自VA的血液主要流向脑血管，而来自CCA的血液则流向脑内和脑外血管。鉴于通过VA和CCA的血流分布存在推测差异，我们认为在SGB同侧观察到的CCA血流增加主要是由于脑外血管扩张，与脑血流变化无关。
