J Cerebrovasc Endovasc Neurosurg.  2013 Sep;15(3):260-266. 10.7461/jcen.2013.15.3.260.

The Pterional Approach and Extradural Anterior Clinoidectomy to Clip Paraclinoid Aneurysms

• Kim JS
• Lee SI
• Jeon KD
• Choi BS

• KMID: 1491450
• DOI: http://doi.org/10.7461/jcen.2013.15.3.260

Abstract

OBJECTIVE
The surgical clipping of paraclinoid segment internal carotid artery aneurysms is considered difficult because of the complex anatomical location and important neighboring structures. Our experiences of pterional craniotomy and extradural anterior clinoidectomy (EAC) to clip paraclinoid aneurysms are reported herein.
METHODS
We present two patients with paraclinoid aneurysms who underwent surgical clipping using pterional craniotomy and EAC. The clinical results and operative techniques were reviewed from the patients' medical records.
RESULTS
EAC improves the surgical field in the suprasellar and periclinoid regions. Clinically, a good outcome was obtained in both cases. No surgical complications directly resulting from the EAC were observed.
CONCLUSION
Favorable surgical results can be obtained with pterional craniotomy and EAC for the clipping of paraclinoid aneurysms. EAC is advocated for the clipping of paraclinoid aneurysms.

Keyword

Paraclinoid aneurysm; Extradural; Anterior clinoidectomy; Pterional craniotomy

MeSH Terms

Aminocaproic Acids
Aneurysm
Carotid Artery, Internal
Craniotomy
Humans
Surgical Instruments
Aminocaproic Acids

Figure

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  Fig. 1 Schematic diagram: head position for pterional craniotomy; after pterional craniotomy and removal of the sphenoid lesser wing (Blue area), Schematic diagram of the lesser wing of the sphenoid and of the optic-canal-roof drilling (Red area), Schematic diagram of the anterior clinoid process's centrally shelled or hollowed-out area (Green area).

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  Fig. 2 Schematic diagram of the middle skull base posterior to anterior view: (A) superior orbital fissure (Blue line) and meningoorbital band (Red line). (B) Intraoperative photography: The temporalis muscle (Dark circle) is retracted red inferiorly. The meningoorbital band (MOB) and outer dura layer of the lateral wall of the cavernous sinus is peeled. The outer two-thirds of sphenoid ridge (Asterisk) is drilled away. The entire lesser wing of the sphenoid is seen (Open arrow). The dura mater of the frontal and temporal fossa is divided to expose the MOB (Beneath the suction tip) superomedially and the dural fold of the superior orbital fissure (Closed arrow) inferolaterally. The dark circle is temporalis muscle and muscle retractor.

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  Fig. 3 Intraoperative photography of the anterior clinoid process's centrally shelled or hollowed-out area (The green area of the Fig 1). The outer two-thirds of sphenoid ridge (Asterisk) and the entire lesser wing (Open arrow) are drilled. The temporalis muscle (Dark circle) is retracted red inferiorly. (A) The apex of the ACP is removed using a diamond burr and constant irrigation in an inside cancellous bone to lateral cortical bone. The cortical bone of the ACP (Closed arrow) is remained like a thinned onion shells on the periosteal layer in the clinoid space. The diamond drill is aimed so that the walls can be easily fractured and circumferentially dissected free of the surrounding dural-fold-canal drilling. (B) Intraoperative photography: The optic canal (Open arrow) is broken using a diamond drill. The optic strut (Arrowhead) is remained between the opened clinoid space and the optic canal. The optic strut is dissected from the optic sheath and cleared away using a micropunch.

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  Fig. 4 Case 1: This 46-year-old woman presented with dizziness and diplopia. Her visual-field examination showed right inferior quadrantanopia. (A) Digital subtraction angiography of the right carotid artery shows that the aneurysm is directed superomedially. (B) 2-dimensional (2D) CT angiography shows that the anterior clinoid process (ACP) is an obstacle to the clipping of an aneurysm. (C) Postoperative 2D CT angiography shows that the entire ACP was removed and the aneurysm was clipped with 2 15-mm straight clips.

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  Fig. 5 Case 2: This 42-year-old woman presented with sudden severe headache. (A) The preoperative axial computed tomography (CT) scan shows right-frontal-base hemorrhage. Note that the aneurysm is situated at the site of the hemorrhage. The anterior clinoid process (ACP) is an obstacle to the clipping of an aneurysm. (B) The 3-dimensional (3D) CT angiography shows the superolateral side of the paraclinoid internal carotid artery aneurysm. (C) The postoperative CT scan 3D reconstruction skull image shows that the entire ACP was removed and that the aneurysm was clipped with 2 15-mm curved clips.

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