Department of Neurosurgery, University of South Florida, Tampa, Florida, USA.
Neurosurgery. 2010 Mar;66(3 Suppl):126-34. doi: 10.1227/01.NEU.0000366117.04095.EC.
The transoral approach provides the most direct exposure to extradural lesions of the ventral craniovertebral junction. Lesions that extend beyond the exposure provided by the standard transoral approach require an extended transoral modification. The exposure can be expanded in the sagittal and axial planes by adding mandibulotomy, mandibuloglossotomy, palatotomy, and transmaxillary approaches to the standard transoral approach. Extended transoral approaches increase the surgical complexity and the risk of cosmetic and functional complications. Until recently, selection of an extended approach has been arbitrary and dependent on the surgeon's familiarity with the surgical approach.
We review the literature of extended transoral approaches and analyze the different modifications in terms of the technical aspects, added exposure, and complications.
Classic approaches and recently published morphometric studies that objectively document the gain in exposure provided by several modifications were analyzed and tabulated to outline the limits of exposure and risk of complications associated with the various modifications.
Transmaxillary approaches expand the exposure to include the sphenoid sinus and upper lateral clivus. To expand the exposure more inferiorly to C4-C5, mandibulotomy or mandibuloglossotomy can be applied. Mandibuloglossotomy increases the rostral exposure as well to the upper third of the clivus. Palatotomy increases rostral exposure without requiring a facial incision or perioperative tracheostomy, but is associated with a significant risk of velopharyngeal insufficiency.
Surgical decisions can be based on comprehensive preoperative evaluation of anatomy, pathology, and radiographic studies to maximize exposure while minimizing complications.
经口入路为颅颈交界区腹侧硬膜外病变提供了最直接的显露。超出标准经口入路显露范围的病变需要进行经口延长入路修正。通过添加下颌骨切开术、下颌舌骨切开术、硬腭切开术和经上颌入路，可以在矢状面和轴面方向扩大标准经口入路的显露范围。经口延长入路增加了手术的复杂性，并增加了美容和功能并发症的风险。直到最近，延长入路的选择都是任意的，取决于外科医生对手术入路的熟悉程度。
我们回顾了经口延长入路的文献，并根据技术方面、增加的显露范围和并发症分析了不同的修正方法。
分析并列出了经典入路和最近发表的形态计量学研究，这些研究客观记录了几种修正方法提供的显露增加情况，以概述各种修正方法相关的显露范围和并发症风险的限制。
经上颌入路扩大了显露范围，包括蝶窦和上外侧斜坡。为了更向下扩展显露至 C4-C5，可以应用下颌骨切开术或下颌舌骨切开术。下颌舌骨切开术还增加了向颅底的显露范围至斜坡的上三分之一。硬腭切开术增加了向颅底的显露范围，而无需面部切口或围手术期气管切开术，但与显著的咽闭合不全风险相关。
手术决策可以基于全面的术前解剖、病理和影像学评估，以在最小化并发症的同时最大化显露范围。
