Introduction

The anatomy of the supraclavicular part of the brachial plexus is highly variable, therefore the aim of this study was to perform a systematic review and meta-analysis of the various origins of the long thoracic, dorsal scapular, suprascapular and subclavian nerves.

Materials and methods

Major electronic databases were searched to identify all cadaveric studies investigating the morphology of the supraclavicular part of the brachial plexus. Data on the origins of these nerves were extracted and classified. A random effects meta-analysis was performed to state the pooled prevalence estimates.

Results

A total of 26 studies, constituting a total of 1021 cases, were deemed eligible for inclusion into the meta-analysis. The usual origin of the long thoracic nerve from the C5, C6 and C7 roots was observed in 78.1% (95% CI 69.4–86.7%) of cases and 21.9% (95% CI 13.3–30.6%) had unusual origins. An accessory long thoracic nerve occurred in 0.3% (95% CI 0–0.7%) of cases. The overall prevalence of the dorsal scapular nerve arising from its usual origin the C5 root was found in 85.2% (95% CI 75.7–94.6%) of cases, while 14.8% (95% CI 5.4–24.3%) appeared abnormal. The suprascapular nerve emerged from its usual point on the superior trunk in 89.8% (95% CI 85.1–94.4%) of cases and in 10.2% (95% CI 5.6–14.9%) of cases had a variable origin. An accessory suprascapular nerve was present in 0.2% (95% CI 0–0.6%). Two possible sites of origin of the subclavian nerve were noted and the typical origin from the superior trunk was found in 98.3% (95% CI 96.3–100%) of cases and variable origin from the C5 root in 1.7% (95% CI 0–3.7%). All unusual origins of each nerve were much less common.

Conclusions

The nerves emerging from the supraclavicular part of the brachial plexus express a wide spectrum of potential origins. Based on their various origins, a new classification system for all the nerves belonging to the supraclavicular part was proposed. Knowledge of these variations and their prevalence data is important to prevent iatrogenic injuries and to state useful landmarks for interventions in the axilla.

中文翻译：

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臂丛神经解剖变异的荟萃分析：第二部分——锁骨上部分的分支

介绍

臂丛神经锁骨上部分的解剖结构变化很大，因此本研究的目的是对胸长、肩胛背、肩胛上和锁骨下神经的各种起源进行系统回顾和荟萃分析。

材料和方法

搜索了主要的电子数据库以识别所有研究臂丛神经锁骨上部分形态的尸体研究。这些神经起源的数据被提取和分类。进行了一项随机效应荟萃分析以说明汇总的患病率估计值。

结果

共有 26 项研究，共 1021 例，被认为符合纳入荟萃分析的条件。在 78.1% (95% CI 69.4–86.7%) 的病例中观察到来自 C5、C6 和 C7 神经根的胸长神经的常见起源，21.9% (95% CI 13.3–30.6%) 具有不寻常的起源。0.3% (95% CI 0–0.7%) 的病例出现副长胸神经。在 85.2% (95% CI 75.7–94.6%) 的病例中发现源自其通常起源 C5 根的肩胛背神经的总体患病率，而 14.8% (95% CI 5.4–24.3%) 出现异常。在 89.8% (95% CI 85.1–94.4%) 的病例和 10.2% (95% CI 5.6–14.9%) 的病例中，肩胛上神经从其上干的通常点出现。0.2% (95% CI 0–0.6%) 存在副肩胛上神经。注意到锁骨下神经的两个可能起源部位，在 98.3% (95% CI 96.3–100%) 的病例中发现来自上干的典型起源和在 1.7% (95% CI 0 –3.7%）。每条神经的所有异常起源都不太常见。

结论

从臂丛神经锁骨上部分发出的神经表现出广泛的潜在起源。根据它们的不同起源，提出了属于锁骨上部分的所有神经的新分类系统。了解这些变异及其流行数据对于预防医源性损伤和说明腋窝干预的有用标志很重要。