Extended subtemporal transtentorial approach to the anterior incisural space and upper clival region: experience with posterior circulation aneurysms.
BACKGROUND
Although most posterior circulation aneurysms are currently treated by endovascular means, some are not amenable to this treatment modality. The narrow working window afforded by the anterolateral and lateral surgical approaches often translates into suboptimal visualization and limited maneuverability.


OBJECTIVE
We present a modified technique of tentorial incision and reflection that optimizes the exposure achieved with the traditional subtemporal approach and report our clinical experience in a series of posterior circulation aneurysms.


METHODS
Retrospective review of patients operated via an extended subtemporal transtentorial approach for posterior circulation aneurysms. The modified tentorial incision implies dissection of the trochlear nerve along its dural canal up to its entrance into the cavernous sinus and incision of a tentorial flap that extends up to Meckel cave, which is then reflected far anterolaterally. Clinical and radiological data were reviewed.


RESULTS
This series comprises 18 patients (21 procedures). Ten patients presented (56%) with a subarachnoid hemorrhage. Aneurysms most frequently arose from the basilar tip (61%) and were of small size (50%) and saccular morphology (72%). Two patients underwent surgery following unsuccessful endovascular treatment. Aneurysm treatment was successful on the first attempt in 90% (19/21) and after a second attempt in 10% (2/21). Documented postoperative palsies of the oculomotor (n = 3) and trochlear (n = 1) nerves were all transient. No procedure-related mortality occurred.


CONCLUSIONS
This modified technique of tentorial incision and reflection optimizes visibility, anatomic orientation, and maneuverability by increasing the rostrocaudal and anterolateral exposure obtained via the extended subtemporal transtentorial route without permanent postoperative trochlear nerve deficit.
Department of Neurosurgery, David Geffen School of Medicine at UCLA, Los Angeles, California.
Nancy
N
McLaughlin
Neil A
NA
Martin
D000328:Adult; D000368:Aged; D001488:Basilar Artery / Q000473:pathology; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000150:complications / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000009:adverse effects; D015840:Oculomotor Nerve Diseases / Q000209:etiology; D012086:Reoperation; D012189:Retrospective Studies; D013345:Subarachnoid Hemorrhage / Q000150:complications / Q000473:pathology / Q000601:surgery; D016896:Treatment Outcome; D014321:Trochlear Nerve / Q000473:pathology; D020432:Trochlear Nerve Diseases / Q000209:etiology; D055815:Young Adult