Pandit J J, Dutta D, Morris J F
Nuffield Department of Anaesthetics, John Radcliffe Hospital, Oxford OX3 9DU, UK.
Br J Anaesth. 2003 Nov;91(5):733-5. doi: 10.1093/bja/aeg250.
This study was undertaken to investigate why the superficial cervical plexus block for carotid endarterectomy is so effective. Initial consideration would suggest that a superficial injection would be unlikely to block all terminal fibres of relevant nerves. One possibility is that the local anaesthetic crosses the deep cervical fascia and blocks the cervical nerves at their roots.
Superficial cervical plexus blocks (injections just below the investing fascia) were performed using methylene blue (30 ml) in four cadavers. In one additional control cadaver, a deep cervical plexus injection was performed. In a second control cadaver, a subcutaneous injection (superficial to investing fascia) was performed at the posterior border of the sternomastoid muscle.
Anatomical dissection showed that with superficial block there was spread of the dye to structures beneath the deep cervical fascia. In the first control, dye remained in the deep cervical space. In the second control, dye remained subcutaneous.
The superficial cervical space communicates with the deep cervical space and this may explain the efficacy of the superficial block. The method of communication remains unknown. Our findings also indicate that the suitable site of injection for the superficial cervical plexus block is below the investing fascia of the neck, and not just subcutaneous.
本研究旨在探究为何颈动脉内膜切除术的颈浅丛阻滞如此有效。初步考虑表明，浅表注射不太可能阻滞相关神经的所有终末纤维。一种可能性是局部麻醉药穿过颈深筋膜并在神经根处阻滞颈神经。
在四具尸体上使用亚甲蓝（30毫升）进行颈浅丛阻滞（在颈深筋膜下方注射）。在另外一具对照尸体上进行颈深丛注射。在第二具对照尸体上，在胸锁乳突肌后缘进行皮下注射（在颈深筋膜浅层）。
解剖显示，进行浅部阻滞时染料扩散到了颈深筋膜下方的结构。在第一个对照组中，染料保留在颈深间隙。在第二个对照组中，染料保留在皮下。
颈浅间隙与颈深间隙相通，这可能解释了浅部阻滞的有效性。沟通方式尚不清楚。我们的研究结果还表明，颈浅丛阻滞的合适注射部位是在颈部的颈深筋膜下方，而不仅仅是皮下。
