Sala-Blanch Xavier, Boezaart André P, McLeod Graeme A, Reina Miguel A
Human Anatomy and Embryology Unit, Faculty of Medicine, Universitat de Barcelona, Barcelona, Spain; Department of Anesthesiology, Hospital Clinic, University of Barcelona, Barcelona, Spain.
Department of Anesthesiology, University of Florida College of Medicine, Gainesville, FL, USA; Lumina Health, Surrey, UK.
Br J Anaesth. 2025 Feb;134(2):545-556. doi: 10.1016/j.bja.2024.11.030. Epub 2025 Jan 10.
We investigated the intraneural spread of injected fluid in brachial plexus nerve roots, examining the potential for intrafascicular spread and identifying influencing factors.
Twelve deliberate ultrasound-guided intraneural injections were performed at the ventral rami of the brachial plexus nerve roots at their exits from the neuroforamina in six fresh, unembalmed, cryopreserved human cadavers. A 22-G, 30-degree bevel echogenic regional anaesthesia needle was used. Each injection contained 1 ml of heparinised erythrocytes as a marker. Nerve swelling observed on ultrasound images confirmed intraneural injection.
Intraneural spread was observed in 12 ventral rami of the six brachial plexi: C5 (1), C6 (3), C7 (5), C8 (2), and T1 (1). Among these, intrafascicular spread was detected in eight cases, six in monofascicular roots and two in bifascicular roots, though none in roots with three or more fascicles. The fascicle diameters in these cases (2.1-3.8 mm) were at least twice the diameter of the needle orifice, measured at 0.9 mm, which was entirely inside the fascicles. In the four cases with intraneural but without intrafascicular spread, the fascicle diameters were about two times the diameter of the needle orifice in three instances, but the entire needle orifice was not always inside a fascicle.
In contrast with multifascicular peripheral nerves, intrafascicular spread was possible after deliberate intraneural injections near the neuroforaminal canal exit of the brachial plexus nerve roots in several monofascicular or bifascicular ventral rami if the fascicle diameter was more than twice the needle opening length and the entire opening was inside the fascicle.
我们研究了注入的液体在臂丛神经根内的扩散情况，探讨了束膜内扩散的可能性并确定了影响因素。
在六具新鲜、未防腐、冷冻保存的人体尸体中，于臂丛神经根从椎间孔穿出处的腹侧支进行了12次超声引导下的神经内注射。使用的是22G、30度斜面的超声引导区域麻醉针。每次注射含有1毫升肝素化红细胞作为标记物。超声图像上观察到的神经肿胀证实了神经内注射。
在六个臂丛的12个腹侧支中观察到神经内扩散：C5（1例）、C6（3例）、C7（5例）、C8（2例）和T1（1例）。其中，在8例中检测到束膜内扩散，6例在单束根中，2例在双束根中，但在有三个或更多束的根中未检测到。这些病例中的束直径（2.1 - 3.8毫米）至少是针孔直径（0.9毫米）的两倍以上，且针孔完全位于束内。在4例有神经内但无束膜内扩散的病例中，3例束直径约为针孔直径的两倍，但并非整个针孔都始终位于束内。
与多束外周神经不同，如果束直径超过针开口长度的两倍且整个开口位于束内，在臂丛神经根椎间孔管出口附近进行有意的神经内注射后，在几个单束或双束腹侧支中可能会发生束膜内扩散。
