1, the concept of pterygoid point: it is an H-shaped seam formed by the intersection of frontal bone, parietal bone, temporal bone and sphenoid wing. Wing position: located in the temporal fossa, above the midpoint of zygomatic arch at the two transverse fingers.

2. Clinical significance: the bone wall here is weak, and the anterior branch of the middle meningeal artery passes through it. It is easy to fracture when hit by violence, and the fracture is easy to damage blood vessels and form epidural hematoma. The anterior branch of the middle meningeal artery passes through the deep surface, which has a motor language center.

In clinical surgery, pterional craniotomy is also one of the important surgical methods, that is, pterional approach, by removing part of frontal bone, temporal bone and sphenoid wing, craniotomy is performed from the outside to expose brain tissue.

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The pterional approach, also known as "pterional craniotomy between fascia" or "frontotemporal sphenoid approach", is one of the most commonly used surgical approaches in skull base surgery and microsurgery. The pterional approach is characterized by using the lateral fissure as a natural anatomical space, with minimal traction on brain tissue, and can explore the skull base lesions in sellar region, anterior cranial fossa, middle cranial fossa and upper clivus.

The ideal principle of craniotomy is not to interfere with brain tissue when separating and removing lesions. Therefore, in craniotomy, we should not only use the natural plane and space of skull base, but also pull too much brain tissue. Sphenoid crest is the plane that separates frontal lobe from temporal lobe through pterional approach, and the other plane is the base of frontal lobe and the orbital apex above orbit.

These planes are projected directly from the surface of the brain to the parasellar region, forming a small cone with the junction of frontal lobe and temporal lobe at the top and the craniotomy area at the bottom. The body is a surgical approach and is dynamic.

Removal of the lateral sphenoid ridge and part of the orbital apex can enlarge this natural space along its bottom surface, and separate the lateral fissure along the cone apex, which can further expand the space and form a large cone workspace with the tip pointing to the threshold of the island. The depth of the cone is the shortest distance from the skull cap to the sella turcica.

Through this big cone, the arachnoid membrane between the frontotemporal lobe and the base of the frontal lobe can be opened, so the whole frontal lobe can be lifted from the skull base without traction or little traction. Through the amplification, illumination and special stereoscopic transmission of the operating microscope, the skull base structure can be exposed to the cerebellopontine cistern and the internal auditory canal from the parasellar and the upper part of the chiasma down through the interpeduncular cistern and the pons.

The pterional approach craniotomy is mainly suitable for aneurysms in the anterior part of Willis circle and the upper end of basilar artery, as well as tumors in orbit, retroorbit, sellar region, parasellar region, optic chiasma, anterior basal lobe, posterior slope and pons. Just gently stretch the lateral underside of the frontal and temporal lobes.

Fixing the head position, fully removing the skull base bone, releasing cerebrospinal fluid from basal cistern and systematically separating subarachnoid space are the keys to success.