Neurology India Medknow Publications on behalf of the Neurological Society of India ISSN: 0028-3886 EISSN: 1998-4022 Vol. 58, Num. 5, 2010, pp. 786-788

Neurology India, Vol. 58, No. 5, September-October, 2010, pp. 786-788

Letter to Editor

Embolization of a ruptured aneurysm of the distal anterior inferior cerebellar artery with parent artery preservation

Yin Jinbo, Zhou Zheng, He Jiaquan, Yang Hui, Liu Jun

Department of Neurosurgery, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, P R, China

Correspondence Address:
Liu Jun
Department of Neurosurgery, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, P R
China
liujun19651026@yahoo.com.cn

Date of Acceptance: 17-Jul-2010

Code Number: ni10217

PMID: 21045515

DOI: 10.4103/0028-3886.72170

Sir,

Intracranial aneurysms occurring in the distal anterior inferior cerebellar artery (AICA) are rare. Most distal AICA aneurysms are treated surgically with neck clipping. Surgical treatment is difficult, particularly in patients with acute subarachnoid hemorrhage (SAH). ^[1] Endovascular treatment may be an alternative method. ^[2] However, most aneurysms of distal AICA aneurysms were embolized with parent artery occlusion. We describe here in a patient with distal AICA aneurysm successfully treated by endovascular embolization with parent artery preservation.

A 42-year-old female developed sudden onset of headache, vomiting and right ear tinnitus. On admission at five hours, she had Grade II (Hunt and Hess) SAH with right tinnitus and mild neck stiffness, Computerized tomography (CT) scan demonstrated no abnormalities [Figure - 1]. Lumbar puncture indicated SAH. Digital subtraction angiography (DSA) was performed; the right vertebral angiogram revealed a saccular aneurysm (2.2-5.2 mm in size) at the right internal auditory meatal loop, fed by the right AICA [Figure - 2]. Endovascular treatment was performed 9 days after admission. An Excelsior^® SL-10 microcatheter was inserted into the right AICA and five GDC bare platinum coils (2 mm×4 cm, 2 mm×3 cm, 2 mm×3 cm, 2 mm×2 cm, 2 mm×2 cm) (Boston Scientific, USA) were deployed in the aneurysm sac. Postoperative vertebral angiogram revealed complete elimination of the aneurysm and satisfactory AICA patency [Figure - 3]. Postoperative course was uneventful; the patient was discharged 9 days after embolization with mild right tinnitus. The clinical follow-up occurred 6 months, 12 months and 20 months after discharge. Hearing disturbance completely recovered 3 months after discharge. However, the patient refused all follow-up imaging on financial grounds

The reported incidence of a Aneurysms of the AICA distal segment varies between are rare, with a reported incidence of 0.1 and -0.5%. ^[3] Since first descriptionreported by Schwartz in 1948, ^[4] less than <100 cases have been reported appeared in the literature. ^[5] Most cases of distal AICA aneurysms were treated surgically with neck clipping, trapping and wrapping. ^[6] However, surgical treatment of cerebellar artery aneurysms is challenging because of the deep location and adhesion to cranial nerves, particularly CVII and CVIII cranial nerves. ^[1] Recently, endovascular coiling with GDCs has been used to manage surgically difficult aneurysms. Endovascular treatment of vertebrobasilar artery saccular aneurysms provides more satisfactory results than direct surgery. Unfortunately, treatment of distal AICA aneurysms usually sacrifice the parent artery owning to the distance between the AICA origin and the aneurysm.

Occlusion of the proximal AICA results in syndromes related predominantly to the lateral portions of the brain stem and cerebellar peduncles. Several authors cited no ischemic complications occurring after sacrifice of the distal AICA because of sufficient collateral circulation from the ipsilateral superior cerebellar artery or posterior inferior cerebellar artery. ^[7] However, fine perforating vessels arising from the proximal AICA penetrate into the pons. Retrograde thrombosis due to distal occlusion of AICA may cause a devastating brain stem or cerebellar infarction. Because the aneurysm in this patient was saccular, we chose coil embolization with parent artery preservation in order to prevent ischemic complications. The aneurysm sac was confined and the minimum diameter was 2.2 mm. To ensure the safety of coil embolization, we chose the smallest and softest GDCs fitting the minimum diameter. Aneurysms of distal AICA treated endovascularly with parent artery preservation are extremely rare. To our knowledge, only three cases have been reported. ^[8] In our patient, no ischemic complications occurred due to preservation of the AICA.

It was the aim of this study to evaluate the feasibility of embolization of distal AICA aneurysm with parent artery preservation. Despite significant technical difficulties, good outcome was obtained in our patient. However, this strategy is not amenable to all patients as fusiform or dissecting aneurysm is still difficult to manage without sacrificing the parent artery.

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