====== Ophthalmic artery aneurysm surgery ======

//J.Sales-Llopis//


//Neurosurgery Service, Alicante University General Hospital, Alicante Institute for Health and
Biomedical Research (ISABIAL - FISABIO Foundation), Alicante, Spain.//

The key features of successful surgical treatment of these lesions include establishing control of the proximal artery, adequate exposure of the [[aneurysm neck]], and successful obliteration of the aneurysm with minimal manipulation of the optic nerve
((Batjer HH, Kopitnik TA, Giller CA, Samson DS. Surgery for paraclinoidal
carotid artery aneurysms. J Neurosurg. 1994 Apr;80(4):650-8. PubMed PMID:
8151343.
)).

The [[ophthalmic artery aneurysm]]s can treated safe and effective through a [[frontolateral approach]]
((Wang JT, Kan ZS, Wang S. [Surgical management of ophthalmic artery aneurysms
via minimally invasive frontolateral approach]. Zhonghua Yi Xue Za Zhi. 2017 Apr 
18;97(15):1179-1183. doi: 10.3760/cma.j.issn.0376-2491.2017.15.014. Chinese.
PubMed PMID: 28427127.
)).

Microsurgical clipping of large ophthalmic-carotid artery (OA) aneurysms is technically challenging. Among the reported approaches, pterional combined epidural and subdural approach is one of the efficient choices
((Hu P, Zhang HQ, Li XJ. Step-wise pterional combined epidural and subdural
approach to clip large carotid-ophthalmic segment aneurysms. Acta Neurochir
(Wien). 2019 Mar;161(3):607-610. doi: 10.1007/s00701-019-03833-4. Epub 2019 Feb
13. PubMed PMID: 30756244.
)).


The most important risk associated with [[clipping]] [[ophthalmic artery aneurysm]]s is a new [[visual deficit]]. Meticulous microsurgical technique is necessary during [[anterior clinoidectomy]], aneurysm dissection, and [[clip]] application to optimize visual outcomes, and aggressive medical management postoperatively might potentially decrease the incidence of delayed visual deficits. As the results of endovascular therapy and specifically [[flow diverter]]s become known, they warrant comparison with these surgical benchmarks to determine best practices
((Kamide T, Tabani H, Safaee MM, Burkhardt JK, Lawton MT. Microsurgical clipping
of ophthalmic artery aneurysms: surgical results and visual outcomes with 208
aneurysms. J Neurosurg. 2018 Jan 26:1-11. doi: 10.3171/2017.7.JNS17673. [Epub
ahead of print] PubMed PMID: 29372879.
)).

For [[ophthalmic artery aneurysm treatment]] if necessary, the [[ophthalmic artery]] may be sacrificed without worsening of vision in the vast majority.

Surgery is technically demanding because these aneurysms are often large and may extend into the [[cavernous sinus]]
((Hosobuchi Y. Direct surgical treatment of giant intracranial aneurysms. J Neurosurg. 1979;51(6):743–756.))
((Sundt T M Jr, Piepgras D G. Surgical approach to giant intracranial aneurysms. Operative experience with 80 cases. J Neurosurg. 1979;51(6):731–742.))
((Almeida G M, Shibata M K, Bianco E. Carotid-ophthalmic aneurysms. Surg Neurol. 1976;5(1):41–45.))
((Kattner K A, Bailes J, Fukushima T. Direct surgical management of large bulbous and giant aneurysms involving the paraclinoid segment of the internal carotid artery: report of 29 cases. Surg Neurol. 1998;49(5):471–480.))
((Nutik S L. Ventral paraclinoid carotid aneurysms. J Neurosurg. 1988;69(3):340–344.))
((Nutik S. Carotid paraclinoid aneurysms with intradural origin and intracavernous location. J Neurosurg. 1978;48(4):526–533)).
----
The anterior clinoid process (ACP) interferes with clipping. It is necessary to remove the ACP followed by optic canal unroofing to expose the ophthalmic segment aneurysm. The ACP resection can be performed intradurally or extradurally. The proponents of extradural clinoidectomy maintain that the dural layer protects the brain and cortical vessels during the drilling, and prevents bone dust and bleeding into the subarachnoid space
((Beretta F, Andaluz N, Zuccarello M. Aneurysms of the ophthalmic (C6) segment
of the internal carotid artery: treatment options and strategies based on a
clinical series. J Neurosurg Sci. 2004 Dec;48(4):149-56. PubMed PMID: 15876983.
)).

By contrast, intradural clinoidectomy provides a clear view of the ACP, ICA, and optic nerve, which are protected during clinoidectomy
((Wang J, Kan Z, Wang S. Microsurgical treatment of carotid-ophthalmic aneurysm 
associated with multiple anterior and posterior circulation aneurysms: A case
report. Medicine (Baltimore). 2017 Apr;96(16):e6672. doi:
10.1097/MD.0000000000006672. PubMed PMID: 28422878; PubMed Central PMCID:
PMC5406094.
)).

For [[unruptured intracranial aneurysm]], drill off [[anterior clinoid process]] via an extradural approach before opening dura  to approach aneurysm neck maybe safe. Not for ruptured.

Care must be taken to avoid [[optic nerve injury]] caused by the retraction and/or the heat of the [[drill]]
((Kumon Y, Sakaki S, Kohno K, Ohta S, Ohue S, Oka Y. Asymptomatic, unruptured
carotid-ophthalmic artery aneurysms: angiographical differentiation of each type,
operative results, and indications. Surg Neurol. 1997 Nov;48(5):465-72. PubMed
PMID: 9352810.
)).
----
Cutting the [[falciform ligament]] early decompresses the [[optic nerve]], and helps minimize worsening of [[visual impairment]] from surgical manipulation.

In most cases, a side angled clip can be placed paralell to the parent artery along the neck of the aneurysm
((Day AL. Clinicoanatomic features of supraclinoid aneurysms. Clin Neurosurg.
1990;36:256-74. Review. PubMed PMID: 2403885.
)).

===== Contralateral approach =====

see [[Ophthalmic artery aneurysm contralateral approach]].