Microanatomical Studies Of The Keyhole Approaches In The Subtemporal Region And The Infratemporal Region

Partâ… : Design and Microanatomical Study of Anterior Subtemporal Transepidural-Anterior Transpetrous Keyhole Approach Assisted by NeuronavigationObjective: The aim of the study is to design a novel anterior subtemporal transepidural-anterior transpetrous keyhole approach by applying the keyhole conception and investigate its feasibility. The novel keyhole approach is performed assisted by neuronavigation and microanatomical structures are observed, which can be regard as the base of this approach in clinical use.Methods: The new keyhole approach was imitated in ten adult cadaveric heads fixed in 10% formalin and perfused intracranial vessels with colored silicone. The cadavers head was rotated contralaterally about 90 degrees to keep the zygomatic arch horizontal to the floor. A vertical lineal skin incision of approximately 4cm was created from the point at the superior rim of the zygomatic arch about 1cm anterior to the tragus. An oval-shaped craniotomy approximately 2 to 2.5cm in diameter was performed close to the cranial base. The lateral wall of cavernous sinus was exposed through the epidural avenue. The internal contents of the cavernous sinus were exposed through the operative triangles of cavernous sinus. At the navigationally advantageous location of cochlea and internal acoustic meatus, the Day rhomboid construct and the petrous apex below the trigeminal ganglion were removed in turn after extradural exposure of the floor of middle cranial floor. The upper and middle clival regions, cerebellopontine angle were exposed, and the anatomic structures exposed were observed. The coordinates of key landmarks that defined the triangles of cavernous sinus, Day rhomboid construct and the...