Relationship between the ophthalmic artery and the dural ring of the internal carotid artery. Clinical article.
ABSTRACT The ophthalmic artery (OphA) usually arises from the intradural internal carotid artery (ICA), and the extradural origin has also been known. However, the interdural origin is extremely rare. The purpose of this paper was to clarify the origin of the OphA in patients with a paraclinoid aneurysm in the ICA based on intraoperative findings.
The authors retrospectively examined 156 patients who underwent direct surgical treatment for 166 paraclinoid aneurysms during a 17-year period. Based on intraoperative findings, 119 ophthalmic arteries were analyzed with respect to their origins.
The OphA originated from the intradural ICA on 102 sides (85.7%), extradural on 9 (7.6%), and interdural on 8 (6.7%). Although the extradural origin might be recognized preoperatively, it was difficult to distinguish the interdural origin of the OphA from the intradural one.
The incidence of the interdural origin was 6.7% and was not as rare as the authors expected. Neurosurgeons should know the possible existence of the interdural origin of the OphA to section the medial side of the dural ring.
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ABSTRACT: This retrospective study gives a summary of ophthalmic artery (OA) variations to serve as guidelines for surgical interventionists and trainees. Pubmed and Medline searches were conducted. The OA usually arises intradurally (superomedial, anteromedial, or rarely superolateral) from the internal carotid artery (ICA). Rare extradural origin (primitive dorsal OA) (PDOA) remnant and extremely rare interdural origin (primitive ventral OA) (PVOA) remnant are of significance when sectioning the dural ring. Rarely, a persistent PDOA with ICA origin, or a PDOA remnant with inferolateral trunk origin, enters the orbit via the superior orbital fissure (SOF) for sole or partial orbital supply. Extremely rare, the PDOA and PVOA persist and form double OAs that arise from the ICA and run via the SOF and optic foramen. Occasionally, the OA arises from the middle meningeal artery (MMA), when both the PDOA and VDOA regress and enter the orbit via the SOF. Sole orbital supply via the external carotid artery (ECA), i.e. meningo-ophthalmic artery and/or MMA branches, or dual OAs (ECA and ICA origins) may occur. Other rare OA origins include anterior or posterior communicating artery; anterior or middle cerebral artery; basilar artery; posterior inferior cerebellar artery; and the carotid bifurcation. Primitive arteries (persistent or remnant), and/or abnormal anastomoses play pivotal roles in manifestations of OA variations. Of clinical importance are orbital collateral routes and dangerous extracranial-intracranial anastomoses. Awareness of OA origins and collateral routes is imperative for transarterial embolizations or infusion chemotherapy in the ECA territory to prevent visual complications. Clin. Anat., 2014. © 2014 Wiley Periodicals, Inc.Clinical Anatomy 09/2014; DOI:10.1002/ca.22470 · 1.16 Impact Factor
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ABSTRACT: The carotid cave was first described more than 20 years ago, but its relationships to the dural rings defining the clinoid segment of the internal carotid artery (ICA), the carotid collar, and the adjacent osseous structures need further definition. To further define the microanatomy of the carotid cave and its relationships to the adjacent structures. : The cave and its relationships were examined in cadaveric specimens using 3 to 40× magnification. The cave is an intradural pouch, found in 19 of 20 paraclinoid areas, that extends below the level of the distal dural ring between the wall of the ICA and the dural collar surrounding the ICA. The distal dural ring is tightly adherent to the anterior and lateral walls of the ICA adjacent the anterior clinoid process and optic strut but not on the medial and posterior sides of the artery facing the upper part of the carotid sulcus where the carotid cave is located. The superior hypophyseal artery frequently arises in the cave. The depth and circumferential length of the cave averaged 2.4 mm (range, 1.5-5 mm) and 9.9 mm (range, 4.5-12 mm), respectively. Aneurysms arising at the level of the cave, although appearing on radiological studies to extend below the level of the upper edge of the anterior clinoid, may extend into and may be a source of subarachnoid space. The surgical treatment of aneurysms arising in the cave requires an accurate understanding of the relationships of the cave to the ICA, dural rings, and carotid collar.Neurosurgery 11/2011; 70(2 Suppl Operative):300-11; discussion 311-2. DOI:10.1227/NEU.0b013e3182431767 · 3.03 Impact Factor
Article: Paraclinoid carotid aneurysms[Show abstract] [Hide abstract]
ABSTRACT: Paraclinoid aneurysms originate from the internal carotid artery between the distal dural ring and the posterior communicating artery. Giant, multiple and bilateral aneurysms are more frequent in this group of aneurysms. Surgical clipping of these aneurysms is technically challenging due to the adjacent bony anatomy and neurovascular structures. Operative mortality has been reduced substantially due to advances in microsurgical techniques. However, there is still no uniformity with respect to the surgical procedures used, especially regarding the use of skull-base approaches and resection of the anterior clinoid process. Due to the complexity of these aneurysms, endovascular procedures are used frequently to treat these aneurysms. We have reviewed the anatomical, radiological aspects and classification of paraclinoid aneurysms. Surgical and endovascular management options are also reviewed.Journal of Clinical Neuroscience 01/2011; 18(1):13-22. DOI:10.1016/j.jocn.2010.06.020 · 1.32 Impact Factor