Surgical Treatment of Posterior Circulation Aneurysms – Anatomical Study and Surgical Technique

AbstractPosterior circulation aneurysms represent 10–15% of intracranial aneurysms. The diagnosis is usually secondary to subarachnoid hemorrhage due to its initial asymptomatic presentation and higher risk of rupture compared with aneurysms in the anterior circulation. The surgical treatment of posterior circulation aneurysms is complex and challenging for neurosurgeons because of the particular anatomy of the posterior circulation with its close relation to the brainstem and cranial nerves and also because of the depth and narrowness of the surgical approach. Aneurysms from different locations have specific anatomical relationships and surgical approaches for better visualization and dissection. Therefore, a detailed anatomy knowledge of the posterior circulation is mandatory for an individualized preoperative planning and good neurological and angiographic outcomes. We selected the main aneurysm sites on the posterior circulation, such as: posterior inferior cerebellar artery, basilar trunk, basilar bifurcation, posterior cerebral artery (PCA) and superior cerebellar artery for a detailed description of the relevant anatomy related to aneurysm, and the main surgical approaches for its surgical treatment. Furthermore, we performed a literature review with the most recent outcomes regarding to the surgical treatment of posterior circulation aneurysms.

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Embolization of Posterior Circulation Aneurysms with Detachable Coils

Interventional Neuroradiology ◽

10.1177/15910199980040s127 ◽

1998 ◽

Vol 4 (1_suppl) ◽

pp. 127-130 ◽

Cited By ~ 1

Author(s):

K. Kazekawa ◽

T. Fukushima ◽

M. Tomonaga ◽

T. Kawano ◽

T. Kawaguchi ◽

...

Keyword(s):

Posterior Inferior Cerebellar Artery ◽

Posterior Circulation ◽

Superior Cerebellar Artery ◽

Anterior Inferior Cerebellar Artery ◽

Cerebellar Artery ◽

Long Term Follow Up ◽

Detachable Coils ◽

Posterior Circulation Aneurysms ◽

Vertebrobasilar Junction

We evaluated the usefulness of endovascular treatment of posterior circulation aneurysms with GDCs and IDCs, Five cases were treated with IDCs, and 15 cases were treated with GDCs. In this study, 8 aneurysms were identified at the basilar bifurcation, 3 at the P1 segment of the pasterior cerebral artery, 1 at the origin of the superior cerebellar artery, 2 at the vertebrobasilar junction, 1 at the origin of the posterior inferior cerebellar artery, 1 at the distal anterior inferior cerebellar artery, and 4 dissecting aneurysms at the vertebral artery. Thirteen of the aneurysms were small (< 12 mm), 5 were large (13–24 mm), and 2 were giant (> 25 mm). Of the 20 patients, 14 patients returned to their previous occupation. Patients with permanent deficits included 2 patients with infarction caused by thromboembolic complications during the embolization procedure, and 2 with infarction caused by vasospasm. There were 2 deaths. The outcomes of the patients seemed favorable. However, long-term follow-up is necessary to determine the usefulness of detachable coils.

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Posterior circulation aneurysms: A 10-year institutional analysis

Indian Journal of Neurosurgery ◽

10.4103/2277-9167.102271 ◽

2012 ◽

Vol 01 (02) ◽

pp. 119-123

Author(s):

Saurabh Sharma ◽

Ansari Abuzer ◽

Ashish Suri ◽

Shailesh Gaikwad ◽

N.K. Mishra ◽

...

Keyword(s):

Posterior Inferior Cerebellar Artery ◽

Posterior Circulation ◽

Superior Cerebellar Artery ◽

Anterior Inferior Cerebellar Artery ◽

Poor Grade ◽

Cranial Nerve Palsies ◽

Cerebellar Artery ◽

Posterior Circulation Aneurysms ◽

Grade Ii ◽

Multimodality Approach

Abstract Aneurysms are uncommon and challenging to manage. A retrospective study was designed to report 53 patients who are treated from June 2002 to June 2011. The mean age at presentation was 46.34 ± 13.67 years (males, 26). Clinical features included subarachnoid hemorrhage (median Hunt and Hess Grade II, n = 42), cranial nerve palsies (9), hydrocephalus (5), and incidentally diagnosed (5). Locations included superior cerebellar artery (3), posterior cerebral artery (2), basilar trunk (4), vertebral (8), anterior inferior cerebellar artery (AICA) (5), posterior inferior cerebellar artery (PICA) (13), vertebrobasilar junction (6), and basilar top (13). Management included both endovascular intervention (26) and surgery (19), and both (2). Five patients presented as poor grade and underwent only extraventricular drain placement while one patient had thrombosed aneurysm and was managed conservatively. Mortality was 26.4% (n = 14) and morbidity included vasospasm (10), meningitis (2), pseudomeningocele (2), pneumonitis (2), and myocardial infarction (1). Posterior circulation aneurysms are highly challenging. They require the multimodality approach, and decision regarding surgery or embolization has to be individualized.

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Surgical clipping of a ruptured posterior inferior cerebellar artery aneurysm

Neurosurgical FOCUS ◽

10.3171/2015.v1.focus14554 ◽

2015 ◽

Vol 38 (videosuppl1) ◽

pp. Video12

Author(s):

M. Yashar S. Kalani ◽

Peter Nakaji ◽

Joseph M. Zabramski ◽

Robert F. Spetzler

Keyword(s):

Posterior Inferior Cerebellar Artery ◽

Cranial Nerves ◽

Artery Aneurysm ◽

Posterior Circulation ◽

Endovascular Techniques ◽

Surgical Clipping ◽

Cerebellar Artery ◽

Posterior Circulation Aneurysms ◽

Pica Aneurysms ◽

Lower Cranial Nerves

Posterior circulation aneurysms are commonly treated with endovascular techniques. In select cases, microsurgery remains an essential tool for treating these lesions. We present a case of a ruptured posterior inferior cerebellar artery (PICA) aneurysm approached via a craniotomy. Given the labyrinth of neurovascular bundles present in the posterior fossa, surgical exposure of PICA aneurysms can be challenging. This video demonstrates the steps of the craniotomy, subarachnoid dissection, mobilization of the vertebral artery and lower cranial nerves, and clipping of the aneurysm.The video can be found here: http://youtu.be/fQSxQj7oL0U.

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Beware of Nihilism: Favorable Outcome despite Poor Admission Status in Posterior Circulation Aneurysms after Aneurysmal Subarachnoid Hemorrhage

Journal of Neurological Surgery Part A Central European Neurosurgery ◽

10.1055/s-0040-1719142 ◽

2021 ◽

Author(s):

Nina Brawanski ◽

Sepide Kashefiolasl ◽

Sae-Yeon Won ◽

Joachim Berkefeld ◽

Elke Hattingen ◽

...

Keyword(s):

Subarachnoid Hemorrhage ◽

Mortality Rate ◽

Cerebral Artery ◽

Coil Embolization ◽

Posterior Inferior Cerebellar Artery ◽

Posterior Circulation ◽

Anterior Circulation ◽

Ruptured Aneurysms ◽

Admission Status ◽

Posterior Circulation Aneurysms

Abstract Objective As shown in a previous study, aneurysm location seems to influence prognosis in patients with subarachnoid hemorrhage (SAH). We compared patients with ruptured aneurysms of anterior and posterior circulation, undergoing coil embolization, concerning differences in outcome and prognostic factors. Methods Patients with SAH were entered into a prospectively collected database. We retrospectively identified 307 patients with aneurysms of the anterior circulation (anterior cerebral artery, carotid bifurcation, and middle cerebral artery) and 244 patients with aneurysms of the posterior circulation (aneurysms of the basilar artery, posterior inferior cerebellar artery, posterior communicating artery and posterior cerebral artery). All patients underwent coil embolization. The outcome was assessed using the modified Rankin Scale (mRS; favorable [mRS 0–2] vs. unfavorable [mRS 3–6]) 6 months after SAH. Results In interventionally treated aneurysms of the anterior and posterior circulation, statistically significant risk factors for poor outcome were worse admission status and severe cerebral vasospasm. If compared with patients with ruptured aneurysms of the anterior circulation, patients with aneurysms of the posterior circulation had a significantly poorer admission status, and suffered significantly more often from an early hydrocephalus. Nonetheless, there were no differences in outcome or mortality rate between the two patient groups. Conclusion Patients with a ruptured aneurysm of the posterior circulation suffer more often from an early hydrocephalus and have a significantly worse admission status, possibly related to the untreated hydrocephalus. Nonetheless, the outcome and the mortality rate were comparable between ruptured anterior and posterior circulation aneurysms, treated by coil embolisation. Therefore, despite the poorer admission status of patients with ruptured posterior circulation aneurysms, treatment of these patients should be considered.

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Anterior Inferior Cerebellar Aneurysm Treated by Aneurysm Resection and Intracranial Artery Anastomosis in situ: A Case Report and Literature Review

Frontiers in Surgery ◽

10.3389/fsurg.2021.669433 ◽

2021 ◽

Vol 8 ◽

Author(s):

Chaojue Huang ◽

Shixing Qin ◽

Wei Huang ◽

Yongjia Yu

Keyword(s):

Surgical Treatment ◽

Posterior Inferior Cerebellar Artery ◽

Cranial Nerves ◽

Anterior Inferior Cerebellar Artery ◽

Intracranial Artery ◽

Disturbance Of Consciousness ◽

Cerebellar Artery ◽

Wide Range ◽

Aneurysm Resection

Background: Anterior inferior cerebellar artery (AICA) aneurysms are relatively rare in clinical practice, accounting for <1% of all intracranial arteries. After the diagnosis and location are confirmed by angiography, magnetic resonance, and other imaging examinations, interventional, or surgical treatment is often used, but some complex aneurysms require reconstructive surgery.Case Description: An 8-year-old male child was admitted to the hospital due to sudden disturbance of consciousness for 2 weeks. The head CT showed hematocele in the ventricular system with subarachnoid hemorrhage in the basilar cistern and annular cistern. On admission, he was conscious, answered correctly, had a soft neck, limb muscle strength was normal, and had no cranial nerves or nervous system abnormalities. A preoperative examination showed the right side of the anterior distal arteries class under the circular wide neck aneurysm, the distal anterior inferior cerebellar artery supplying a wide range of blood to the cerebellum, the ipsilateral posterior inferior cerebellar artery absent, and the aneurysm close to the VII, VIII nerves. The aneurysm was successfully treated by aneurysm resection and intracranial artery anastomosis in situ of a2 AICA-a2 AICA.Conclusions: AICA aneurysms are relatively rare; in this case, a complex wide-necked aneurysm was successfully treated by aneurysm resection and anastomosis in situ of a2 AICA-a2 AICA. This case can provide a reference for the surgical treatment of complex anterior cerebellar aneurysms.

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Expanding the Indications for Flow Diversion: Treatment of Posterior Circulation Aneurysms

Neurosurgery ◽

10.1093/neuros/nyz344 ◽

2019 ◽

Vol 86 (Supplement_1) ◽

pp. S76-S84

Author(s):

Nimer Adeeb ◽

Christopher S Ogilvy ◽

Christoph J Griessenauer ◽

Ajith J Thomas

Keyword(s):

Antiplatelet Agents ◽

Posterior Circulation ◽

Flow Diversion ◽

High Morbidity ◽

Complication Rates ◽

Anterior Circulation ◽

Risk Of Rupture ◽

Lower Complication ◽

Ischemic Complications ◽

Posterior Circulation Aneurysms

Abstract Posterior circulation aneurysms are often associated with a higher risk of rupture and compressive symptoms compared to their anterior circulation counterpart. Due to high morbidity and mortality associated with microsurgical treatment of those aneurysms, endovascular therapy gained ascendance as the preferred method of treatment. Flow diversion has emerged as a promising treatment option for posterior circulation aneurysms with a higher occlusion rate compared to other endovascular techniques and a lower complication rate compared to microsurgery. While treatment of saccular and dissecting aneurysms is often associated with comparatively good outcomes, fusiform and dolichoectatic aneurysms should be carefully selected prior to treatment to avoid devastating thromboembolic complications. Occlusion of covered posterior circulation branches showed no correlation with ischemic complications, and appropriate antiplatelet regimen and switching Clopidogrel nonresponders to different antiplatelet agents were associated with lower complication rates following flow diversion of posterior circulation aneurysms.

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Case Report: Endovascular Treatment of a Giant Distal PICA Aneurysm in Association With a Cerebellar AVM: A Report on Treatment Considerations and a Literature Review

Frontiers in Neurology ◽

10.3389/fneur.2020.611377 ◽

2020 ◽

Vol 11 ◽

Author(s):

Hassan A. Khayat ◽

Christine M. Hawkes ◽

Almunder R. Algird

Keyword(s):

Posterior Inferior Cerebellar Artery ◽

Superior Cerebellar Artery ◽

Management Approach ◽

Parent Vessel ◽

Cerebral Angiogram ◽

First Case ◽

Cerebellar Artery ◽

Risk Of Rupture ◽

The Right ◽

Pica Aneurysms

Background: Distal posterior inferior cerebellar artery (PICA) aneurysms are uncommon intracranial vascular lesions. The coincidence of these aneurysms and Arteriovenous malformation (AVM) is even more rare. Since 1956, a total of 57 cases of distal PICA aneurysms associated with AVM have been reported with clear and adequate description. None of these reports describe a giant prenidal aneurysm at this particular location. The paucity of natural history data as well as lack of consensus about treatment strategies in such cases present a significant challenge that requires an individualized management approach.Case Description: A 68-year-old male presented with recurrent episodes of nausea and vomiting precipitated by physical exertion and change of head position. An MRI of the brain demonstrated a giant partially thrombosed right posterior inferior cerebellar artery (PICA) aneurysm with mass effect on the floor of the fourth ventricle. A conventional cerebral angiogram revealed a giant (3.1 x 3.1 x 2.8cm) distal right PICA pre-nidal aneurysm with two smaller distal PICA aneurysms. An AVM (Spetzler-Martin Grade 1) supplied by the right PICA as well as the right superior cerebellar artery (SCA) was also identified on cerebral angiography (not seen on an MRI). Endovascular coil embolization with parent vessel sacrifice was performed to occlude the giant aneurysm. Due to the asymptomatic nature, low risk of rupture, and the patient's age, AVM treatment was deferred.Conclusion: This paper presents the first case of a giant PICA aneurysm associated with cerebellar AVM. For PICA aneurysm-AVM complexes, meticulous evaluation of the morphology, associated anatomy, and comparative risk analysis for both lesions are key for treatment planning. Distal PICA aneurysms can be treated safely with parent vessel occlusion, particularly in the case of prenidal aneurysms.

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Skull base approaches to the basilar artery

Neurosurgical FOCUS ◽

10.3171/foc.2005.19.2.4 ◽

2005 ◽

Vol 19 (2) ◽

pp. 1-12 ◽

Cited By ~ 34

Author(s):

L. Fernando Gonzalez ◽

Sepideh Amin-Hanjani ◽

Nicholas C. Bambakidis ◽

Robert F. Spetzler

Keyword(s):

Skull Base ◽

Basilar Artery ◽

Posterior Inferior Cerebellar Artery ◽

Free Edge ◽

Posterior Circulation ◽

Surgical Instruments ◽

Petrous Apex ◽

Superior Cerebellar Artery ◽

Anterior Inferior Cerebellar Artery ◽

Cerebellar Artery

Posterior circulation lesions constitute approximately 10% of all intracranial aneurysms. Their distribution includes the basilar artery (BA) bifurcation, superior cerebellar artery, posterior inferior cerebellar artery, and anterior inferior cerebellar artery. The specific features of a patient's aneurysm and superb anatomical knowledge help the surgeon to choose the most appropriate approach and to tailor it to the patient's situation. The main principle that must be applied is maximization of bone resection. This allows the surgeon to work within a wider corridor, which facilitates the use of surgical instruments and minimizes retraction of the brain. The management of aneurysms within the posterior circulation requires expertise in skull base and vascular surgery. Endovascular treatments have become increasingly important, but in this paper the authors focus on the surgical management of these difficult aneurysms. The paper is divided into three parts: the first section is a brief review of the anatomy of the BA; the second part is a review of the techniques associated with the management of posterior fossa aneurysms; and in the third section the authors describe the different approaches, their nuances and indications based on the location of the aneurysm, and its relationship to the surrounding bone (especially the clivus, dorsum sellae, and the free edge of the petrous apex).

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Characteristics and surgical treatment of dolichoectatic and fusiform aneurysms

Journal of Neurosurgery ◽

10.3171/jns.1996.84.2.0185 ◽

1996 ◽

Vol 84 (2) ◽

pp. 185-193 ◽

Cited By ~ 189

Author(s):

John A. Anson ◽

Michael T. Lawton ◽

Robert F. Spetzler

Keyword(s):

Cerebral Artery ◽

Posterior Inferior Cerebellar Artery ◽

Posterior Circulation ◽

Small Subset ◽

Consecutive Series ◽

Anterior Circulation ◽

Initial Development ◽

Posterior Circulation Aneurysms ◽

Surgical Treatments ◽

Anterior Circulation Aneurysms

✓ Dolichoectatic and fusiform aneurysms represent a small subset of cerebral aneurysms and are often among the most difficult to treat. A consecutive series of 40 patients with 41 of these two types of aneurysms is presented, including their clinical characteristics and surgical treatments. Common to all aneurysms was the pathological involvement of a length of blood vessel with separate inflow and outflow sites (nonsaccular). However, dolichoectatic aneurysms have markedly different symptoms and surgical treatments depending on their location in either the anterior or posterior circulation. Anterior circulation aneurysms involved the petrous internal carotid artery (ICA) in one, the supraclinoid ICA in three, the middle cerebral artery in 13, and the anterior cerebral artery in four patients. Posterior circulation aneurysms involved the basilar artery in 13, the vertebral artery in six, and the posterior inferior cerebellar artery in one patient. Various surgical procedures were performed, including direct clipping, trapping with bypass, proximal occlusion, resection with reanastomosis, transposition, aneurysmorrhaphy with thrombectomy, and wrapping. There was no surgical mortality in the patient series, and treatment was effective in many patients. Overall, outcome at late follow up was good (Glasgow Outcome Scale scores 1–2) in 78% of patients. Patients with anterior circulation aneurysms had better outcomes than patients with posterior circulation aneurysms, with good outcomes in 90% and 65% of the cases, respectively. Dolichoectatic and giant serpentine aneurysms may develop from smaller fusiform aneurysms and represent a spectrum of the same pathological entity. Arterial dissection may also play a role in the initial development of these aneurysms.

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Acute Treatment of Ruptured Fusiform Posterior Circulation Posterior Cerebral, Superior Cerebellar, and Posterior Inferior Cerebellar Artery Aneurysms With FRED Flow Diverter: Report of 5 Cases

Operative Neurosurgery ◽

10.1093/ons/opy194 ◽

2018 ◽

Vol 16 (5) ◽

pp. 549-556 ◽

Cited By ~ 3

Author(s):

Dan Laukka ◽

Riitta Rautio ◽

Melissa Rahi ◽

Jaakko Rinne

Keyword(s):

Treatment Time ◽

Brain Infarction ◽

Treatment Options ◽

Posterior Inferior Cerebellar Artery ◽

Flow Diverter ◽

External Ventricular Drainage ◽

Posterior Circulation ◽

Superior Cerebellar Artery ◽

Technical Success Rate ◽

Cerebellar Artery

Abstract BACKGROUND Flow diverter (FD) treatment of ruptured fusiform posterior cerebral artery (PCA), posterior inferior cerebellar artery (PICA), and superior cerebellar artery (SCA) aneurysms are limited to single reports. OBJECTIVE To study the safety and efficacy of FD treatment for ruptured fusiform aneurysms of the PCA, SCA, and PICA. METHODS Five patients with ruptured posterior circulation fusiform aneurysms and treated with a Flow-Redirection Endoluminal Device (FRED/FRED Jr; Microvention, Tustin, California) stent in the acute phase of subarachnoid hemorrhage between 2013 and 2016 were included and reviewed retrospectively. RESULTS Two aneurysms located on the PICA, 2 on PCA, and 1 on the SCA. Mean treatment time with FD was 5.8 d (range, 0-11 d) from ictus. The technical success rate was 100%. On admission 2 patients were Hunt and Hess grade 1, 2 patients grade 3, and 1 patient grade 4. At discharge, 4 patients (80%) were independent (modified Ranking Scale (mRS) ≤2) and 1 patient had severe disability (mRS 4). None of the patients had aneurysmal rebleeding. All 5 aneurysms were completely occluded on angiographic follow-up (range, 3-22 mo). One patient had permanent intraprocedural in stent thrombosis and brain infarction. One patient had spontaneous nonaneurysmal intracerebral hemorrhage 1 mo after FD treatment. External ventricular drainage was inserted in 3 patients and ventriculoperitoneal shunt in 2 patients without hemorrhagic complications despite dual antiplatelet therapy. CONCLUSION FD could be considered as a treatment option for ruptured fusiform aneurysms located on PCA, PICA, or SCA when other treatment options are challenging.

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