Microanatomical Study And Clinical Application On Subtemporal Keyhole Approach

Objective:The purpose of this study is to describe and anatomically analyze the operating spaces provided by the subtemporal keyhole approach,and offer the technique of the approach to clinical application.To explore its superiority and clinical value.Methods:(1)Anatomic:Anatomic features were studied in 20 sides of adult embalmed cadaveric heads perfused with colored silicone.A vertical epifascial skin incision approximately 50 mm is created approximately 10 mm anterior to the external auditory meatus.To study the relationship between various levels of the muscles, nerves, blood vessels, bone.An craniotomy approximately 25 mm in diameter is performed close to the cranial base.Firstly beginning the intradural procedure after the craniotomy,analyze the operating spaces provided by the approach and measure the important datas of the main anatomic structures.Then beginning the extradural procedure,to analyze the operating spaces of cavernous sinus and measure the important data of its anatomic structure.To observe the scope of petroclival region after the bony resection of Day and expanding scope,then measure and compare the area.(2)Clinic:Select some typical cases of skull base tumors,surgerical treatment under subtemporal keyhole approach.Results:(1)Anatomic:When procedure from the intradural,the anatomical structures of the interpeduncular cistern, the upper petroclival area and brainstem ventrolateral can be well exposured.Internal carotid artery, posterior communicating artery, posterior cerebral artery, oculomotor nerve and the tentorial free edge is a sign of intracranial location.The distance between the zygomatic arch and oculomotor nerve is 38.82±1.53mm, and the junction of posterior cerebral artery(PCA) and posterior communicating artery(PCoA) is 47.27±2.95mm, and the junction of internal carotid artery(ICA) and PCoA is42.95±2.62mm. The distance between the zygomatic arch and foramen rotundum is 45.28±1.45mm, and the foramen ovale is 32.63±1.19mm, and the foramen spinosum is 28.97±0.64mm, and the trigeminal nerve impression is 40.17±0.74mm.When procedure from the extradural,the lateral wall of the cavernous sinus can be exposed and measured:the area of lateromedial triangle is 27.16±2.74mm2, Parkinson's triangle is 54.54±4.78mm2, Mullan triangle is 52.48±5.32mm2, lateral triangle is 24.34±2.26mm2, Glasscock triangle is 46.62±3.35mm2, Kawase triangle is 49.74±5.13mm2.The area of the Day diamond-shaped section is 213.37±17.62mm2, after polishing of the petrous apex,the area is 280.46±28.43mm2, the area larger than before is 67mm2.(2)Clinic:The operation trans subtemporal keyhole approach is performed with endoscopic-assisted in appropriate cases, the effect is ideal.Conclusions:The subtemporal keyhole approach can provide sufficient operating space for exposing tentorial area, middle cranial fossa, metasellar, suprasellar region, cavernous sinus, ventral-lateral pontine, petroclival region.The structure within the cavernous sinus can be exposed through the lateral wall of cavernous sinus. The endoscope-assisted surgery may be to achieve better effect.