Introduction

The lateral antebrachial cutaneous nerve (LACN) is a somatosensory nerve coursing in the lateral portion of the forearm. The nerve is located in a close proximity to the cephalic vein (CV) all along its course with a danger of being injured during venipuncture. The LACN also overlaps and communicates with the superficial branch of the radial nerve (SBRN) in the distal forearm and hand, making the awareness of their relationship of great importance in the treatment of neuroma. The aim of the study was to observe the relationship of the LACN to surrounding structures as well as its branching pattern and distribution.

Materials and methods

Ninety-three cadaveric forearms embalmed in formaldehyde were dissected. The relationship of the LACN to surrounding structures was noted and photographed, and distances between the structures were measured with a digital caliper. The cross-sectional relationships of the LACN and SBRN to the CV were described using heatmaps.

Results

The emerging point of the LACN was found distally, proximally or at the level of the interepicondylar line (IEL). The LACN branched in 76 cases (81.7 %) into an anterior and posterior branch at mean distance of 47.8 ± 34.2 mm distal to the IEL. The sensory distribution was described according to the relationship of the LACN branches to the medial border of the brachioradialis muscle. The LACN supplying the dorsum of the hand was observed in 39.8 % of cases. The LACN and the SBRN intersected in 86 % of upper limbs with communications noticed in 71 % of forearms. The LACN was stated as the most frequent donor of the communicating branch resulting in neuroma located distal to the communication and being fed from the LACN. The relationship of the LACN and the CV showed that the IEL is the most appropriate place for the venipuncture due to maximal calibers of the CV and deep position of the LACN. The LACN was adjacent to the cubital perforating vein and the radial artery in all cases. The medial border of the brachioradialis muscle was observed less than 1.8 mm from the LACN.

Conclusion

The study provides morphological data on the LACN distribution, branching pattern and relationship to surrounding structures in a context of clinical use in different spheres of medicine. The branching pattern of the LACN appears to be more constant compared to data provided by previous authors. We emphasized the meaning of cross-sectional relationship of the LACN to the CV to avoid venipuncture outside the cubital fossa if possible. The posterior branch of the LACN was predicted as appropriate donor of the graft for a digital nerve. The LACN appeared to be in a close proximity within the whole length of the brachioradialis muscle what the orthopedic surgeons must be concerned of. The meaning of the donor-nerve of the communicating branch in neuroma treatment was also introduced.

中文翻译：

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前臂外侧皮神经的临床解剖：介入治疗有安全区吗？

介绍

前臂外侧皮神经（LACN）是在前臂外侧部分走行的体感神经。该神经沿其走向始终紧邻头静脉(CV)，在静脉穿刺过程中存在受伤的危险。LACN 还与前臂远端和手部的桡神经浅支 (SBRN) 重叠并连通，因此认识到它们之间的关系对于神经瘤的治疗非常重要。该研究的目的是观察 LACN 与周围结构的关系及其分支模式和分布。

材料和方法

九十三具用甲醛防腐的尸体前臂被解剖。记录 LACN 与周围结构的关系并拍照，并用数字卡尺测量结构之间的距离。使用热图描述了 LACN 和 SBRN 与 CV 的横截面关系。

结果

LACN 的出现点位于远端、近端或上髁间线 (IEL) 水平。76 例 (81.7%) 的 LACN 分支为前支和后支，距 IEL 的平均距离为 47.8 ± 34.2 mm。根据 LACN 分支与肱桡肌内侧缘的关系来描述感觉分布。在 39.8% 的病例中观察到 LACN 供应手背。LACN 和 SBRN 在 86% 的上肢相交，并在 71% 的前臂中发现通信。LACN 被认为是交通分支最常见的供体，导致神经瘤位于交通远端并由 LACN 供给。LACN 和 CV 的关系表明，由于 CV 的最大口径和 LACN 的位置较深，IEL 是最适合静脉穿刺的位置。在所有病例中，LACN 均邻近肘部穿静脉和桡动脉。观察到肱桡肌的内侧边界距离 LACN 不到 1.8 毫米。

结论

该研究提供了不同医学领域临床应用中 LACN 分布、分支模式以及与周围结构关系的形态学数据。与之前作者提供的数据相比，LACN 的分支模式似乎更加恒定。我们强调了 LACN 与 CV 横截面关系的意义，以避免在肘窝外进行静脉穿刺（如果可能）。LACN 的后支被预测为数字神经移植物的合适供体。LACN 似乎非常接近整个肱桡肌，这是整形外科医生必须关注的问题。还介绍了交通支供体神经在神经瘤治疗中的意义。