Pterional approach [Neurosurgery Wiki]

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====== Pterional approach ======
{{rss>https://pubmed.ncbi.nlm.nih.gov/rss/search/1JKSd2KF3MGwV5na6zBl5OJHa8vMYo-y6zYmqgNy5FSoJd81mw/?limit=15&utm_campaign=pubmed-2&fc=20231011032549}}

Pterional or fronto-temporal craniotomy, developed by Prof. M. G. Yasargil, is among the most familiar skull base surgery techniques
((Yaargil M, Yaşargil M. Interfascial pterional (frontotem-porosphenoidal) craniotomy: Georg Thieme Verlag. 1984:217–20 p.))
((Yaşargil M.G. FJL, Ray M.W. 'The Operative Approach to Aneurysms of the Anterior Communicating Artery. In: al. KHe, editor. Advances and Technical Standards in Neurosurgery, vol 2. Vienna: Springer. 1975))
((Yaşargil MG, Reichman MV, Kubik S. Preservation of the frontotemporal branch of the facial nerve using the interfascial temporalis flap for pterional craniotomy. Technical article. J Neurosurg. 1987 Sep;67(3):463-6. doi: 10.3171/jns.1987.67.3.0463. PMID: 3612281.)).
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The frontotemporal, so-called pterional, approach has evolved with the contribution of many neurosurgeons over the past century. It has stood the test of time and has been the most commonly used transcranial approach in neurosurgery. In its current form, drilling the [[sphenoid wing ]]as far down as the [[superior orbital fissure]] with or without the removal of the [[anterior clinoid process]], thinning the [[orbital roof]], and opening the [[Sylvian fissure]] and [[basal cistern]]s are the hallmarks of this approach. 
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The [[history]] of neurosurgery is filled with descriptions of brave surgeons performing surgery against great odds in an attempt to improve outcomes for their patients. In the distant past, most neurosurgical procedures were limited to trephination, and this was sometimes performed for unclear reasons. Beginning in the Renaissance and accelerating through the middle and late 19th century, a greater understanding of cerebral localization, antisepsis, anesthesia, and hemostasis led to an era of great expansion in neurosurgical approaches and techniques. During this process, frontotemporal approaches were also developed and refined over time. Progress often depended on the technical advances of scientists coupled with the innovative ideas and courage of pioneering surgeons. A better understanding of this history provides insight into where we originated as a specialty and in what directions we may go in the future. In a review Ormond and Hadjipanayis consider the historical events enabling the development of neurosurgery as a specialty, and how this relates to the development of frontotemporal approaches
((Ormond DR, Hadjipanayis CG. The history of neurosurgery and its relation to
the development and refinement of the frontotemporal craniotomy. Neurosurg Focus.
2014 Apr;36(4):E12. doi: 10.3171/2014.2.FOCUS13548. Review. PubMed PMID:
24684325.
)).

===== Indications =====

[[Pterional approach indications]].

===== Positioning =====

The patient should be positioned supine in a neutral position with a pad under the ipsilateral shoulder. The head should be lifted above the level of the heart to promote venous return and secured using a three-pin skull fixation device

{{::pterional_craniotomy_skin_incision.jpg?400|}}

===== Skin incision =====

A curvilinear [[skin incision]] is made from the superior rim of the [[zygomatic arch]], 1 cm anterior to the [[tragus]], to the midline just behind the hairline.

After [[skin incision]] the resulting [[bone flap]] is centered over the depression of the [[sphenoid ridge]]. Approximately 33% of the craniotomy is anterior to the anterior margin of temporalis muscle insertion, ≈ and 66% is posterior.

With the [[craniotome]], starting at the frontal [[burr hole]] the [[craniotomy]] is taken anteriorly across the anterior margin of the [[superior temporal line]], staying as low as possible on the [[orbit]] (to obviate having to rongeur bone, which is unsightly on the forehead). 

===== Soft tissue dissection =====

[[Pterional approach soft tissue dissection]].


===== Pterional craniotomy =====


see [[Pterional craniotomy]].



====Variants====

Orbital Rim (ORo) Zygomatic Arch (ZAo) and Orbito-Zygomatic (OZo) osteotomies can be useful adjuncts to the classical Fronto-Pteriono-Temporal craniotomy in facilitating the exposure of deep seated skull base lesions, sparing brain retraction injuries. 

There are different variants of the pterional approach described, such as the orbito-cranial approach as an extended and the sphenoid ridge keyhole approach as a less invasive approach
((Mizunari T, Murai Y, Kobayashi S, Hoshino S, Teramoto A. Utility of the orbitocranial approach for clipping of anterior communicating artery aneurysms: Significance of dissection of the interhemispheric fissure and the sylvian fissure. J Nippon Med Sch. 2011;78:77–83.))
((Nathal E, Gomez-Amador JL. Anatomic and surgical basis of the sphenoid ridge keyhole approach for cerebral aneurysms. J Neurosurg. 2005;56:178–85.)).

===== Complications =====

[[Pterional craniotomy complications]].

[[Pterional approach complications]].