经中颅窝入路显露颌内动脉的解剖学研究

New approach for transcranial exposure of the internal maxillary artery： surgical anatomy and technique

目的探讨经中颅窝入路显露颌内动脉的新方法。方法成人尸头标本10具，翼点入路开颅，暴露中颅窝底，采取“两步法”磨除中颅窝骨质。首先，沿棘孔的前外侧成一个三角形骨窗，分离翼外肌，循脑膜中动脉或颞深动脉向近心端显露即可定位位于颞下窝的颌内动脉；然后，从后向前沿翼外肌走形方向成一骨槽，分离翼外肌继续暴露颌内动脉至翼腭窝。观察本方法涉及的重要解剖结构及其位置关系，并测量中颅窝骨窗磨除范围、颌内动脉与中颅窝的距离、显露的颌内动脉长度。结果采取“两步法”磨除中颅窝骨质，解剖标识清晰，可以迅速定位颌内动脉，同时可清晰显露颌内动脉与三叉神经各分支的关系。10具尸头中，6具颌内动脉位于翼外肌内侧面，4具位于翼外肌的外侧面。中颅窝底磨除骨窗的前后径为（27．8±4．2）mm，内外侧径为（13．3±1．5）mm。颌内动脉与中颅窝的距离为（16．8±3．2）mm，显露的颌内动脉长度为（17．6±3．3）mm。结论“两步法”磨除中颅窝骨质的技术，能安全、有效地暴露颌内动脉，减少术中邻近神经损伤的概率。

Objective To introduce a new approach through the middle cranial fossa for easy access and safe exposure of the Internal Maxillary Artery （IMA）. Methods Ten specimens were prepared for surgical simulation. After pterional craniotomy and exposing the floor of middle fossa, a two-step drilling was performed. First, a triangular craniectomy was completed anterolateral to the foramen spinosum. By following the middle meningeal artery or deep temporal artery and dividing the lateral pterygoid muscle, the proximal part of IMA was located. Second, a bone slot was drilled in a posterior-to-anterior direction from the anterior aspect of the first craniectomy. Tracing the proximal part, the main trunk of IMA was obtained. The size of the two cranieetomies, depth of IMA from the surface of middle fossa, and the length of exposed IMA were measured. Results The proposed two-step drilling technique allowed both the IMAg trunk andbranches of the trigeminal nerve to be manipulated safely. In six specimens, IMA ran medially to the pterygoid muscle and in the others ran laterally to it. The total craniectomy measured 27.8 ± 4.2 mm in the anterior-posterior direction, and the posterior portion measured 13.3 ± 1.5 mm in the lateral-medial direction. The depth from middlefossa to IMA （16.8±3.2 mm） was equal to the length of IMA exposed （17.6 ±3.3 mm）. Conclusion This new approach provides an efficient and safe method to consistently locate and isolate a segment of IMA.