Pterional Transzygomatic approach

Pterional Transzygomatic approach

This approach allows wide access to different topographic areas (clinoid process region and clinoidal ICA, the entire cavernous sinus (CS), and the posterior fossa from the interpeduncular fossa to the facial nerve) via a lateral trajectory 1).

see Pretemporal transzygomatic transcavernous approach

see Transzygomatic approach with anteriorly limited inferior temporal gyrectomy.



The patient is positioned in the supine position with the head attached to the table with a Mayfield skull clamp. The head is elevated and left parallel to the ground plane.


The incision starts at the level of the lower edge of the zygomatic arch, slightly anterior to the tragus, and extends behind the hairline towards the contralateral pupillary line. In patients with thick subcutaneous tissue, a preauricular incision can be extended downwards quite safely, up to 25 mm below the superior edge of the zygomatic arch.

The anteroposterior position of the incision will depend upon the type and location of the lesion to be treated.

Dissection of the soft tissues

The dissection of soft tissues starts with subgaleal disection until the fatty tissue over the temporal aponeurosis is recognized. This sector roughly corresponds to the anterior fourth of the temporal muscle and is located immediately posterior to the frontal branch of the superficial temporal artery. From there, an incision is made on the external layer of the temporal fascia which, together with the interfascial fat, is dissected anteriorly in that plane to protect the frontal branch of the facial nerve. In this inter- fascial space runs a small vein, perpendicular to the incision, which must be coagulated and cut. Afterwards, the orbital rim is exposed at the top of the field, with the zygomatic arch lying below.

Sectioning of the zygomatic arch

The zygomatic arch is sectioned with two vertical cuts: a posterior cut immediately before the temporo–mandibular joint; and an anterior cut just behind the union of the zygomatic arch and zygomatic bone. Thus, the zygomatic arch is moved downwards, together with the masseter muscle.

The temporal muscle is separated from the skull via retrograde dissection, so as to avoid post-operative muscular atrophy.

A small cuff of muscle and fascia, at the level of the superior temporal line, is kept in place for reinsertion of this muscle at the end of surgery. Thus, the muscle is taken downwards, through the space left by the sectioned zygomatic arch. This procedure allows for complete exposure of the floor of the middle fossa.


A pterional approach (fronto–temporo–sphenoidal craniotomy) is performed in the usual way 2) 3).

The quantity of frontal and temporal bone to be removed depends upon the type and location of the lesion to be resected. The greater wing of the sphenoid bone and the squamous portion of the temporal bone are drilled out until complete exposure of the lateral aspect of the temporal dura is achieved.

Two burr holes are made in the pterion above and below the lower wing of the sphenoid bone and the bone between them is flattened with a burr. A frontotemporal bone flap is cut with a vertical saw that includes the temporal muscle cuff. An additional hole below the upper temporal line may be helpful for this purpose. A free bone flap is lifted elevating and breaking down the bone. In the event of tumors that infiltrate the pterional bone or the external third of the sphenoid wing, it may be necessary to make the craniotomy around the involved bone, which is then removed by drilling or with a bone gouge. This is a pathological bone with reactive hyperostosis and/or tumor infiltration that must be removed, sometimes with profuse vascularization.


The transzygomatic approach offers excellent exposure to the floor of the middle fossa and the lateral wall of the cavernous sinus (both intradurally and extradurally). Also, combined with a pretemporal approach, it affords a good view of the interpeduncular cistern; and using a transtemporal approach, it provides good access to the insular region.

Once the craniotomy has been performed, the anatomical possibilities are numerous:

1.- intradural access to the middle fossa

2.- intradural pretemporal access to the basal cisterns

3.- intradural transtemporal access to the insular region

4.- extradural access to the middle fossa 4).

Case series

José M González-Darder in 2019 presented a prospective series of 26 cases with SWMs larger than 3 cm in one of its main diameter. All patients were studied following the same clinical and imaging procedures. The surgical approach was through a pterional transzygomatic craniotomy. The surgical procedure has the following steps: 1. Extradural tumor devascularization and resection of the hyperostotic and/or infiltrated bone and then intradurally; 2. Intradural tumor debunking; 3. Microdissection of vascular branches and perforators from the capsule; 4. Identification of the optic and oculomotor nerves and internal carotid artery; 5. Tumor capsule dissection and resection; 6. Dural resection or cauterization; 7. Dural and bone reconstruction and closing. Results  All lesions were completely removed. Most complications were transient. The most relevant complication was a large middle cerebral artery infarct with permanent hemiplegia despite a decompressive craniotomy. Conclusion  Large SWMs can be considered as a single pathology regarding the surgical approach and intraoperative microsurgical procedure strategies. The pterional transzygomatic approach allows an extradural devascularization of the tumor and an extensive bone resection that facilitates the intradural stage of tumor resection. The proposed approach allows a wide and radical resection of the duramater and bone that increases the Simpson grade. However, surgery does not control other biological or molecular prognostic factors involved in tumor recurrence 5).

José M González-Darder et al. presented the experience with the transzygomatic pterional approach in the treatment of neurosurgical pathology of the base of the skull located in the middle cranial fossa and surrounding areas.

A retrospective study of pathological findings, surgical outcomes and complications in a series of 31 cases operated on between 2009 and 2011 using a transzygomatic pterional approach.

The lesions involved the sphenoid wing (25.9%), several regions due to invasive growth pattern (19.5%), the temporal lobe (16.1%) and cavernous sinus (12.9%). The others were located in the floor of the middle fossa, Meckel’s cave, incisural space, cisterns, and infratemporal region. The pathological nature of the lesions was: benign meningioma (42%), temporal lobe tumour (19.5%), vascular disease (12.9%), inflammatory lesions (6.4%), atypical meningioma (6.4%), epidermoid cyst (6.4%), neurinoma (3.2%) and poorly differentiated infratemporal carcinoma (3.2%). The approach was usually combined extra-intradural (58.1%) and, less frequently, just extradural (16.1%) or intradural (25.8%). Approach-related complications were minor: haematomas in the wound not requiring treatment (67.8%), superior transient facial paresis (9.7%), transient temporomandibular joint dysfunction (12.9%) and atrophy of the temporal muscle (16.2%). There were no hardware-related complications or cosmetic issues related to the osteotomy and posterior osteosynthesis of the zygomatic arch.

The pterional approach combined with osteotomy of the zygomatic arch allows mobilising the temporalis muscle away from the temporal fossa, consequently exposing its entire surface to complete the temporal craniotomy up to the middle fossa; it helps to access and treat pathology in this region or it can be used as a corridor to approach surrounding areas 6).



Chotai S, Kshettry VR, Petrak A, Ammirati M. Lateral transzygomatic middle fossa approach and its extensions: Surgical technique and 3D anatomy. Clin Neurol Neurosurg. 2014 Dec 29;130C:33-41. doi: 10.1016/j.clineuro.2014.12.014. [Epub ahead of print] PubMed PMID: 25576883.

González-Darder JM, Quilis-Quesada V, Botella-Maciá L. [Transzygomatic pterional approach. Part 2: Surgical experience in the management of skull base pathology]. Neurocirugia (Astur) 2012; 23(03):96–103

Quilis-Quesada V, Botella-Maciá L, González-Darder JM. [Transzygomatic pterional approach. Part 1: anatomical study]. Neurocirugia (Astur) 2012;23(02):47–53

Campero A, Campero AA, Socolovsky M, Martins C, Yasuda A, Basso A, Rhoton A. The transzygomatic approach. J Clin Neurosci. 2010 Nov;17(11):1428-33. doi: 10.1016/j.jocn.2010.03.023. Epub 2010 Aug 6. Review. PubMed PMID: 20692168.

González-Darder JM. Combined Extradural and Intradural Pterional Transzygomatic Approach to Large Sphenoid Wing Meningiomas. Operative Technique and Surgical Results. J Neurol Surg B Skull Base. 2019 Jun;80(3):244-251. doi: 10.1055/s-0038-1668538. Epub 2018 Aug 21. PubMed PMID: 31143566; PubMed Central PMCID: PMC6534744.

González-Darder JM, Quilis-Quesada V, Botella-Maciá L. [Transzygomatic pterional approach. Part 2: Surgical experience in the management of skull base pathology]. Neurocirugia (Astur). 2012 May;23(3):96-103. doi: 10.1016/j.neucir.2012.04.005. Epub 2012 May 19. Spanish. PubMed PMID: 22613467.

Video Atlas of Neuroendovascular Procedures

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Leonardo Rangel-CastillaAdnan SiddiquiElad Levy

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The go-to guide on safely performing state-of-the-art neuroendovascular procedures from top experts!

Unlike traditional textbooks that detail natural historyphysiology, and morphology, Video Atlas of Neuroendovascular Procedures presents basic and complex neuroendovascular procedures and cases with concise text and videos. Renowned neuroendovascular surgeons Leonardo Rangel-CastillaAdnan SiddiquiElad Levy, and an impressive group of contributors have compiled the quintessential neuroendovascular resource. Organized into eight major subtopic sections, this superb video atlas covers a full spectrum of endovascular approaches to diagnose and treat intra- and extracranial neurovascular disease.

The book starts with a section on vascular access and concludes with endovascular complications and management. Forty chapters includes succinct summaries, scientific procedural evidence, the rationale for endovascular intervention, anatomy, required medications, device selection, avoiding complications, and managing potential problems that can arise during procedures. The image-rich clinical cases feature insightful firsthand knowledge and pearls.

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Webinar- Utilizing the exoscope in neurosurgical oncology

Utilizing the exoscope in neurosurgical oncology

Explained by Dr. Nader Sanai

see Video here

The following time-stamps will guide you to certain key points & examples during this webinar:

At 1:30: “Moving from a pure optical platform to a digital platform is something that we are going to see increasingly in our operating rooms”

At 3:10: “As a tumor surgeon, we have multiple information chains, we have the structural MRI, functional MRI, tractography, MR spectroscopy, MAG imaging, fluorescence-guided surgery, intraoperative navigation and all of these things have to be integrated in our brains and extrapolated through our actions with the tumor. I think what this platform (ZEISS KINEVO 900) is enabling us to do, is give us the ability to integrate a lot of this in real-time so that we do not have to do this ourselves and we do not have to be swiveling our heads to look at this scan or that scan as we are operating.”

At 6:01: “Now, the PointLock concept is really one where you want to specifically focus on a particular target in three-dimensional space. But you want to be able to pivot around it without having to find it again. We all do that in the OR and while it may take only few seconds, those are precious seconds where you lose your chain of thoughts. [..] Achieving this at a functional level… and by that I mean the ability where the robot does it for you and you do not have to adjust at all in terms of fine tuning the focus or fine tuning the special referencing [..] I have used it in the OR, really without any training on it and it is something very intuitive.”

At 7:17: “Many of us use MRI spectroscopy (for example) to identify hotspots where we will perform biopsy. For example, in a low grade tumor we want to decrease the chance of missing a focus of transformation. By bookmarking those sites on the microscope, we can make sure that we can go directly to that spot without worrying about aligning the navigation and all of the other anatomical information around it.”

At 9:06: “In brain tumor operations there are many dimensions of the tumor that we need to work along and we often operate – move the microscope – operate. This platform enables you to continuously operate as you are moving. And, if you are using it as an exoscope function (particularly), you, yourself don’t have to move at all. Effectively, the microscope moves and you stay still. [..] it is an important distinction when you are doing a multi-hour operation and you are able to stay in a position of comfort and stability [..] instead of moving around your torso to accommodate the dimension.”

At 11:03: “The next generation of microscope will be something that is not so much part of you but is working in parallel with you. [..] For example, in a far-lateral type approach for lower cranial schwannoma, there are issues in positioning and the angle of view. But here we can operate in a relatively neutral position using 3D 4K visualization.“

At 13:13: Case explanation for Retrosigmoid Crainiotomy for Petrous Face Meningioma using the combination of exoscopic visualization and robotics.

At 13:54: “This is at the point where one can transition to the exoscope. Because the angles of approach that you want as you are trying to pull this tumor away from the brain tumor margins, really can be quite extreme. You can see in the inset where the angle of the microscope head is relative to my head. If I had to stretch to get to that angle I’m going to be relatively uncomfortable and less stable ergonomically with my hands and torso.”

At 15:12: “I would also add that the learning curve for this is not very steep. It is a relatively simple device to adopt into your workflow because many of us have already gotten used to using the foot pedal for basic robotic movements of the microscope head. What this does is: add these additional dimensions of moving in an angle and pivoting around a point. So, it is really like a real-time surveillance image happening as you operate.

At 16.31: “The digital integration of real-time functional imaging, real-time tractography, real-time stimulation mapping data into the cortex will basically make it seamless.”

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