Direct suction decompression and fenestrated clip reconstruction of complex paraclinoid carotid artery aneurysm: operative video and nuances of skull base technique

Cranioorbital Pretemporal Skull Base Approach with Anterior Clinoidectomy for Removal of Large Left Clinoid Meningioma: "Unwrapping" Encircled Internal Carotid Artery and Decompressing Optic Nerve: 2-Dimensional Operative Video

Clinoidal meningiomas are meningiomas arising from or in the vicinity of the anterior clinoid process.1 Despite advanced microsurgical techniques, clinoidal meningiomas remain challenging.2 Extradural anterior clinoidectomy with optical unroofing remains an important tool in skull base surgery, which provides a safe operative corridor, facilitating greater extent of resection and enhancing overall outcome, particularly visual function.2-13 A 66-year-old woman presented with history of visual disturbances. Magnetic resonance imaging revealed a dural-based tumor consistent with a large left clinoidal meningioma, with tumor wrapping (encircling) around the left trunk and internal carotid artery (ICA) bifurcation, elevating the left middle cerebral artery M1 segment, and invading the left optic canal. Left cranio-orbital craniotomy with pretemporal exposure was used (Video 1).1,9 A high-speed diamond drill with irrigation completed the extradural anterior clinoidectomy and optical canal unroofing. Use of a 1-mm Kerrison rongeur should be done with utmost care. The tumor was unwrapped via meticulous piecemeal removal. Final dissection and ICA unwrapping was done when the tumor was debulked enough that dissecting it off the artery was safe and under less tension. Due to its obscurity, final decompression of the left optic nerve with incision and opening of the falciform ligament was performed at the end of the procedure.10 Postoperative neuro-ophthalmologic examination showed a grossly unchanged left visual field with some visual acuity improvement. Resection of tumor encircling the ICA has been described previously;14 however, to the best of our knowledge, this is the first video describing removal of a tumor surrounding the ICA (perfomed by senior author K.I.A.), essentially "unwrapping" the left ICA trunk and its bifurcation. The patient consented to publication.

Entire Orifice Blocking-Assisted Microsurgical Treatment: Clipping of Intracranial Giant Wide-Neck Paraclinoid Aneurysms

OBJECTIVE

Giant wide-neck paraclinoid aneurysms remain a formidable challenge for neurosurgeons due to the brisk retrograde blood flow during surgical clipping. Theoretically, Entire orifice blockade (EOB) by placing a longitudinal intracarotid balloon catheter across the aneurysm neck could achieve a good vascular control in treating cerebral aneurysms, but related studies have been scarce. The aim of this study was to evaluate the safety and efficiency of the EOB-assisted microsurgical technique for treating giant wide-neck paraclinoid aneurysms.

METHODS

Clinical data and treatment summaries of patients with giant wide-neck paraclinoid aneurysms who underwent EOB-assisted microsurgical clipping were retrospectively reviewed.

RESULTS

A total of 26 patients were analyzed. All but 3 patients harbored unruptured aneurysms. The mean largest diameter of the aneurysms was 26.8±2.0 mm, and the mean neck size was 12.5±2.4 mm. All lesions were successfully clipped without residual aneurysms. Post-operative images revealed no major branch occlusion due to thromboembolic complications. Four patients presented neurologic deficits caused by vasospasm, 3 of which were completely resolved by postoperative treatment. At a mean follow-up time of 1.86 ± 0.95 years (range, 0.5-3.5 years), none of the patients died, and 96.2% (n = 25) of the patients had favorable clinical outcomes with modified Rankin Scale values of 0-2.

CONCLUSIONS

For patients with giant wide-neck paraclinoid aneurysms, EOB-assisted microsurgical clipping is a safe and useful procedure for obtaining vascular control, for softening and shrinking the aneurysm sac and for providing a wide and clean operative field that allows the clip to be effectively placed.