Objectives The lateral supraorbital (LSO) approach is a less-invasive alternative to the pterional craniotomy that provides rapid transsylvian access. Establishing familiarity with the LSO technique and its features as compared with other anterolateral approaches is an important component of advanced skull base training. We present a step-by-step demonstration of the LSO approach using cadaveric dissection in a manner that is digestible for trainees at various levels.

Design This is anatomic step-by-step dissection and representative case series.

Setting This study was carried out in the cadaveric dissection laboratory.

Participants A formalin-fixed, latex-injected cadaveric head specimen was dissected under microscopic magnification by a neurosurgery resident under faculty supervision. Following dissection, representative case applications were reviewed.

Main Outcome Measures Dissection and case illustration were the main outcome measures.

Results A single-layer myocutaneous flap is developed, and a single-burr-hole technique is used, followed by extensive drilling of the sphenoid wing. The dura is opened in a C-shaped fashion centered on the Sylvian fissure, exposing the inferior frontal and superior temporal lobes. Labeled photographs of dissections with pertinent anatomical structures are presented. Three case examples illustrating the versatility of the LSO approach, including the resection of a large pituitary adenoma, an inferior frontal melanoma metastasis presenting to the Sylvian surface, and a frontoinsular low-grade glioma, are reviewed.

Conclusions As compared with the pterional craniotomy, the LSO approach involves a shorter incision, smaller craniotomy, and faster exposure; it can be conveniently tailored to various indications. Understanding the step-by-step dissection and indications of the LSO approach is of paramount importance to neurosurgery trainees.

目的 外侧眶上 (LSO) 入路是翼点开颅手术的一种侵入性较小的替代方案，可提供快速的经外侧裂入路。熟悉 LSO 技术及其与其他前外侧入路相比的特点是高级颅底训练的重要组成部分。我们使用尸体解剖以各种级别的学员易于理解的方式逐步演示 LSO 方法。

设计 这是解剖学的逐步解剖和代表性病例系列。

设置 这项研究是在尸体解剖实验室进行的。

参与者 在教职人员的监督下，神经外科住院医师在显微镜放大下解剖了福尔马林固定、注射乳胶的尸体头部标本。解剖后，对代表性案例应用进行了审查。

主要成果指标 解剖和案例说明是主要成果指标。

结果 开发单层肌皮瓣，并使用单钻孔技术，然后对蝶骨翼进行广泛的钻孔。以侧裂为中心，以 C 形方式打开硬脑膜，暴露下额叶和上颞叶。提供了带有相关解剖结构的标记解剖照片。三个案例说明了 LSO 方法的多功能性，包括切除大的垂体腺瘤、额叶下黑色素瘤转移至侧裂表面和额岛低级别胶质瘤。

结论 与翼点入路开颅手术相比，LSO入路切口更短，开颅面积更小，暴露速度更快；它可以方便地针对各种适应症进行定制。了解 LSO 方法的逐步解剖和适应症对于神经外科学员来说至关重要。