Clin Exp Otorhinolaryngol.  2008 Jun;1(2):53-62. 10.3342/ceo.2008.1.2.53.

Endoscopic Skull Base Surgery

• Lee SC
• Senior BA

• KMID: 1486055
• DOI: http://doi.org/10.3342/ceo.2008.1.2.53

Abstract

Endoscopic skull base surgery has undergone rapid advancement in the past decade moving from pituitary surgery to suprasellar lesions and now to a myriad of lesions extending from the cribriform plate to C2 and laterally out to the infratemporal fossa and petrous apex. Evolution of several technological advances as well as advances in understanding of endoscopic anatomy and the development of surgical techniques both in resection and reconstruction have fostered this capability. Management of benign disease via endoscopic methods is largely accepted now but more data is needed before the controversy on the role of endoscopic management of malignant disease is decided. Continued advances in surgical technique, navigation systems, endoscopic imaging technology, and robotics assure continued brisk evolution in this expanding field.

Keyword

Endoscopic; Skull base; Paranasal sinuses; Parasellar; Endonasal

MeSH Terms

Ethmoid Bone
Paranasal Sinuses
Robotics
Skull
Skull Base

Figure

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  Fig. 1 Image guidance navigation system showing fusion of MRI and CT. The fusion of CT and MRI data allows the surgeon to have information on bony anatomy, tumor position and size, as well as location of critical structures such as the carotid artery and optic nerve.

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  Fig. 2 Sellar opening. (A) After the sphenoid sinus is wide opened, the sella is drilled with an irrigating drill with a diamond burr until the bone is eggshell thin. (B) Thin bone is then fractured and removed with curettes. (C) Bony opening is then enlarged with kerrison rongeurs. (D) After the dura is exposed, bipolar coagulation is performed before opening of the dura.

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  Fig. 3 Four hand technique. One surgeon generally holds the endoscope and a suction while the other surgeon dissects with two hands. In this picture, the teaching surgeon is reaching in with forceps to remove specimen for frozen section.

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  Fig. 4 Removal of tuberculum meningioma. Preop and post op MRI of a tuberculum meningioma which was recurrent after a resection several years ago via a subfrontal craniotomy approach. This was resected via a transplanum approach. In the endoscopic view, the carotids (C) and optic nerves (ON) are marked as seen during tumor dissection.

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  Fig. 5 Hydroscopy. In this case hydroscopy was performed after removal of a giant pituitary adenoma by irrigating the sella with normal saline and using a 45 deg endoscope to obtain 360 deg views around the entire periphery to confirm no residual pockets of tumor. (A) The cavernous carotid (C) and cavernous sinus (CS) are seen. (B) View of the floor of the sella.

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  Fig. 6 Infratemporal fossa schwannoma. (A) Preop MRI of lesion. (B) Postop MRI of lesion. (C) Endoscopic view of schwannoma. (D) Lateral dissection. (E) Internal debulking. (F) Endoscopic view after resection demonstrating dehiscent dura and carotid. Patient has a well mucosalized cavity and is free of recurrence at 9 month followup. (Pictures courtesy of Dr. Mark Weissler)

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  Fig. 7 Lateral sphenoid sinus encephalocele. Encephaloceles are managed by first placing a lumbar drain and instilling a dilute solution of fluorescein intrathecally. This allows for definitive indentification of the encephalocele and site of CSF drainage endoscopically. The encephalocele is followed back to the skull base dehiscence with suction and bipolar cautery and then bony defect is exposed and cleaned. A strut of cartilage and bone is then placed across the bony defect and then a mucosal graft is placed as an onlay graft and then tissue glue and merocel sponges are used to secure the graft in place. In this picture, the bipolar was placed through a transpterygoid port and the fluorescein is clearly seen as well as the carotid canal.

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