Fascial layers influence the spread of injectate during ultrasound-guided infraclavicular brachial plexus block: a cadaver study

Abstract

When fascial layers are present in the neurovascular sheath, they impede the spread of injectate during infraclavicular brachial plexus block. Ultrasound detection of these fascial layers is unreliable in cadavers. These findings support the use of greater volumes of injectate or a multiple injection technique when performing this block.

A reliable septum exists between the lateral cord and medial and posterior cords in the costoclavicular region: Clinical and microanatomical considerations in brachial plexus anesthetic blockade

“…In support of previous studies (Brenner et al, 2018; Layera et al, 2020; Monzó & Hadzic, 2020; Morimoto, Popovic, Kim, Kiamzon, & Rosenberg, 2007), we also demonstrated a barrier that presented as a septum between two well‐defined groups of clusters: the lateral cord superficially, and the medial and posterior cords more posteriorly (deeper). The LA was clearly confined to the compartment into which it was injected, supporting the findings of Morimoto et al (2007) and Brenner et al (2018). This would clearly result in variable blockade results if single injections were performed, and also, in principle, in secondary blockade failure for continuous blocks in which the catheter is not placed in the correct or desired compartment(s).…”

Costoclavicular brachial plexus block reduces hemidiaphragmatic paralysis more than supraclavicular brachial plexus block: retrospective, propensity score matched cohort study

“…The differences among studies may be due to differences in the details of the injection techniques, such as the injection duration and pressure limit, as well as differences in the definition of successful blockade [10,19,22]. Several studies have identified the fascial layer within the neurovascular sheath of the brachial plexus [34,35] as a layer that may impede the spread of local anesthetic. In contrast to the single injection technique utilized in the dose-finding study for the CCB [10], the present study used a two-injection technique.…”

Costoclavicular approach to the brachial plexus block: simple or double injection?

“…For instance, Morimoto and colleagues reported the existence of the posterolateral septa to the axillary artery in 15% of ICBPS in patients 5. In a more recent cadaveric study, a lower septum was identified in 60% of dissections that received an injection at the level of ICBPS 6…”