Anatomical Relationships of Intracavernous Internal Carotid Artery to Intracavernous Neural Structures

Abstract

The objective is to correlate the intracavernous internal carotid artery (ICA) with the position of the intracavernous neural structures. The cavernous sinuses of nine injected cadaveric heads were dissected bilaterally. As measured on computed tomographic angiograms from 100 adults, anatomical relationships and measurements of intracavernous ICA and neural structures were studied and correlated to the intracavernous ICA curvature. Intracavernous ICAs were classified as normal and redundant. The meningohypophyseal trunk (MHT) of normal ICAs appeared to be closely related to the abducens nerve compared with redundant ICAs (5.5 AE 2.1 mm versus 10.0 AE 2.5 mm, respectively; p ¼ 0.001). The position of the inferolateral trunk (ILT) varied along the horizontal segment of the intracavernous ICA. On imaging studies the ICA curvature correlated with the kyphotic degree of the skull and similarity of the ICA curvature between sides. The safety margin for preventing iatrogenic intracavernous nerve injury during surgical exploration or transarterial embolization of vascular lesions around the MHT is high with redundant ICAs. In contrast, a transvenous endovascular approach via the inferior petrosal sinus may be too distant to reach the MHT when ICAs are redundant. Approaching lesions of the inferolateral trunk may be the same regardless of ICA type.

Late-Onset Massive Epistaxis due to a Ruptured Traumatic Internal Carotid Artery Aneurysm: A Case Report

“…Their vessels were investigated by several articles. 6,7) Maybe after the PAO of ICA, remaining flow had grown up those collateral arteries. Some researchers have shown ICA stenosis causes significantly increased collateral flow.…”

The abducens nerve: its topography and anatomical variations in intracranial course with clinical commentary

“…CN VI palsy can be induced among others by: pontine lesions (for example, infarction or tumours) [3,40,46], pathologies in the subarachnoid space (especially leading to CN VI compression against the clivus) [3,16,46], arterial compression [13,38], as well as disease processes within the apex of the petrous temporal bone (for instance, petrous apicitis also known as Gradenigo's syndrome) [3,20,26,46]. CN VI topography within the cavernous sinus (CS), including its anatomical relationship to the ICA, is of particular importance [3,22,24,38]. CN VI may be involved in any disease process within CS (for instance, ICA aneurysm, sinus thrombosis, neoplastic infiltration or inflammation) [38,46].…”

“…CN VI may be involved in any disease process within CS (for instance, ICA aneurysm, sinus thrombosis, neoplastic infiltration or inflammation) [38,46]. CN VI palsy may also be associated with medical procedures, such as skull base surgery and endovascular interventions [15,18,22,24,48], spinal traction (CN VI is the most commonly injured cranial nerve in halo orthosis placement) [34] or even lumbar puncture [6,30]. CN VI palsy may also be secondary to systemic diseases (for instance, the nerve can become ischaemic as a result of diabetes or hypertension) [3,46].…”

Microsurgical anatomy of the abducens nerve

“…The microsurgical anatomy of the abducens nerve is important for clinical reasons and surgical approaches because it is located in the petroclival area and cavernous sinus, which are the most complex regions of the skull base. From the origin to the termination of the abducens nerve, it courses along the subarachnoid space (Iaconetta et al, 2007), petroclival region (Ozveren et al, 2002a, 2003; Iaconetta et al, 2003; Ozer et al, 2010), cavernous sinus (Iaconetta et al, 2001, 2007; Jittapiromsak et al, 2010), and orbit (Iaconetta et al, 2007; Shi et al, 2007). The abducens nerve has a long intracranial course along the vascular, neural, ligamentous, and bony structures and is very vulnerable to direct and indirect injury (Takagi et al, 1976; Antoniades et al, 1993; Lazow et al, 1995; Ziyal et al, 2003).…”