Surgical clipping of a ruptured posterior inferior cerebellar artery aneurysm

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.

Download Full-text

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

Arquivos Brasileiros de Neurocirurgia Brazilian Neurosurgery ◽

10.1055/s-0038-1639589 ◽

2018 ◽

Vol 37 (01) ◽

pp. 27-37

Author(s):

Vitor Yamaki ◽

Eric Paschoal ◽

Manoel Teixeira ◽

Eberval Figueiredo

Keyword(s):

Surgical Treatment ◽

Posterior Inferior Cerebellar Artery ◽

Cranial Nerves ◽

Posterior Circulation ◽

Surgical Approaches ◽

Superior Cerebellar Artery ◽

Anterior Circulation ◽

Cerebellar Artery ◽

Risk Of Rupture ◽

Posterior Circulation Aneurysms

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.

Download Full-text

Revascularization of the Posterior Inferior Cerebellar Artery Using the Occipital Artery: A Cadaveric Study Comparing the p3 and p1 Recipient Sites

Operative Neurosurgery ◽

10.1093/ons/opaa023 ◽

2020 ◽

Vol 19 (2) ◽

pp. E122-E129 ◽

Cited By ~ 1

Author(s):

Peyton L Nisson ◽

Xinmin Ding ◽

Ali Tayebi Meybodi ◽

Ryan Palsma ◽

Arnau Benet ◽

...

Keyword(s):

Posterior Inferior Cerebellar Artery ◽

Cranial Nerves ◽

Median Number ◽

Cerebellar Tonsil ◽

Occipital Artery ◽

Recipient Site ◽

Cerebellar Artery ◽

Feasible Alternative ◽

End To End ◽

Lower Cranial Nerves

Abstract BACKGROUND Revascularization of the posterior inferior cerebellar artery (PICA) is typically performed with the occipital artery (OA) as an extracranial donor. The p3 segment is the most accessible recipient site for OA-PICA bypass at its caudal loop inferior to the cerebellar tonsil, but this site may be absent or hidden due to a high-riding location. OBJECTIVE To test our hypothesis that freeing p1 PICA from its origin, transposing the recipient into a shallower position, and performing OA-p1 PICA bypass with an end-to-end anastomosis would facilitate this bypass. METHODS The OA was harvested, and a far lateral craniotomy was performed in 16 cadaveric specimens. PICA caliber and number of perforators were measured at p1 and p3 segments. OA-p3 PICA end-to-side and OA-p1 PICA end-to-end bypasses were compared. RESULTS OA-p1 PICA bypass with end-to-end anastomosis was performed in 16 specimens; whereas, OA-p3 PICA bypass with end-to-side anastomosis was performed in 11. Mean distance from OA at the occipital groove to the anastomosis site was shorter for p1 than p3 segments (30.2 vs 48.5 mm; P < .001). Median number of perforators on p1 was 1, and on p3, it was 4 (P < .001). CONCLUSION Although most OA-PICA bypasses can be performed using the p3 segment as the recipient site for an end-to-side anastomosis, a more feasible alternative to conventional OA-p3 PICA bypass in cases of high-riding caudal loops or aberrant anatomy is to free the p1 PICA, transpose it away from the lower cranial nerves, and perform an end-to-end OA-p1 PICA bypass instead.

Download Full-text

Intracranial Bypass of Posterior Inferior Cerebellar Artery Aneurysms: Indications, Technical Aspects, and Clinical Outcomes

Operative Neurosurgery ◽

10.1093/ons/opx064 ◽

2017 ◽

Vol 13 (5) ◽

pp. 586-595 ◽

Cited By ~ 8

Author(s):

David J. Bonda ◽

Mohamad Labib ◽

Jeffrey M. Katz ◽

Rafael A. Ortiz ◽

David Chalif ◽

...

Keyword(s):

Cranial Nerve ◽

Posterior Inferior Cerebellar Artery ◽

Surgical Techniques ◽

Occipital Artery ◽

Traumatic Aneurysm ◽

Surgical Clipping ◽

Bypass Patency ◽

Cerebellar Artery ◽

Diseased Segment ◽

Pica Aneurysms

Abstract BACKGROUND: For some posterior inferior cerebellar artery (PICA) aneurysms, there is no constructive endovascular or direct surgical clipping option. Intracranial bypass is an alternative to a deconstructive technique. OBJECTIVE: To evaluate the clinical features, surgical techniques, and outcome of PICA aneurysms treated with bypass and obliteration of the diseased segment. METHODS: Retrospective review of PICA aneurysms treated via intracranial bypass was performed. Outcome measurements included postoperative stroke, cranial nerve deficits, gastrostomy/tracheostomy requirement, bypass patency, modified Rankin scale (mRS) at discharge, and mRS at 6 mo. RESULTS: Seven patients with PICA aneurysms treated with intracranial bypass were identified. Five had fusiform aneurysms (4 ruptured, 1 unruptured), 1 had a giant partially thrombosed saccular aneurysm (unruptured), and 1 had a dissecting traumatic aneurysm (ruptured). Two aneurysms were at the anteromedullary segment, 4 at the lateral medullary segment, and 1 at the tonsillomedullary segment. Three patients underwent PICA-to-PICA side to side anastomoses, 2 PICA-to-PICA reanastomosis, 1 vertebral artery-to-PICA bypass, and 1 occipital artery-PICA bypass. Six out of 7 aneurysms were obliterated surgically and 1 with additional endovascular occlusion after the bypass. All bypasses were patent intraoperatively; 2 were later demonstrated occluded without radiological signs or symptoms of stroke. No patients had new cranial nerve deficit postoperatively. With the exception of 1 death due to pulmonary emboli 3 mo postoperatively, all others remain at a mRS ≤ 2. CONCLUSION: Constructive bypass and aneurysm obliteration remains a viable alternative for treatment of PICA aneurysms not amenable to direct surgical clipping or to a vessel-preserving endovascular option.

Download Full-text

Technical strategies to approach aneurysms of the vertebral and posterior inferior cerebellar arteries

Neurosurgical FOCUS ◽

10.3171/foc.2005.19.2.5 ◽

2005 ◽

Vol 19 (2) ◽

pp. 1-5 ◽

Cited By ~ 16

Author(s):

Niklaus Krayenbühl ◽

Carlos A. Guerrero ◽

Ali F. Krisht

Keyword(s):

Posterior Inferior Cerebellar Artery ◽

Cranial Nerves ◽

Foramen Magnum ◽

Lateral Approach ◽

Anatomical Location ◽

Microsurgical Anatomy ◽

Far Lateral Approach ◽

Far Lateral ◽

Pica Aneurysms ◽

Lower Cranial Nerves

Object Aneurysms of the vertebral artery (VA) and proximal posterior inferior cerebellar artery (PICA) are rare and challenging lesions, as they are located in front of the brainstem and surrounded by the lower cranial nerves. Many different approaches have been described for their treatment, and have yielded different results. With the use of different examples of lesions, the authors describe their surgical strategy in the management of VA and PICA aneurysms. Methods The far-lateral approach was used, and the potential of its different extensions according to the specific anatomical location and configuration of different types of aneurysms is emphasized. Conclusions With the present knowledge of the microsurgical anatomy in the region of the foramen magnum, the far-lateral approach can be tailored to the specific anatomical and morphological configuration of an aneurysm in this region with good surgical results.

Download Full-text

Anatomical triangles defining surgical routes to posterior inferior cerebellar artery aneurysms

Journal of Neurosurgery ◽

10.3171/2010.8.jns10759 ◽

2011 ◽

Vol 114 (4) ◽

pp. 1088-1094 ◽

Cited By ~ 33

Author(s):

Ana Rodríguez-Hernández ◽

Michael T. Lawton

Keyword(s):

Cranial Nerve ◽

Posterior Inferior Cerebellar Artery ◽

Surgical Morbidity ◽

Surgical Clipping ◽

Cerebellar Artery ◽

Pica Aneurysms

Object Surgical routes to posterior inferior cerebellar artery (PICA) aneurysms are opened between the vagus (cranial nerve [CN] X), accessory (CN XI), and hypoglossal (CN XII) nerves for safe clipping, but these routes have not been systematically defined. The authors describe 3 anatomical triangles and their relationships with PICA aneurysms, routes for surgical clipping, outcomes, and angiographically demonstrated anatomy. Methods The vagoaccesory triangle is defined by CN X superiorly, CN XI laterally, and the medulla medially. It is divided by CN XII into the suprahypoglossal triangle (above CN XII) and the infrahypoglossal triangle (below CN XII). From a consecutive surgical series of 71 PICA aneurysms in 70 patients, 51 aneurysms were analyzed using intraoperative photographs. Results Forty-three PICA aneurysms were located inside the vagoaccessory triangle and 8 were outside. Of the aneurysms inside the vagoaccessory triangle, 22 (51%) were exposed through the suprahypoglossal triangle and 19 (44%) through the infrahypoglossal triangle; 2 were between triangles. The lesions were evenly distributed between the anterior medullary (16 aneurysms), lateral medullary (19 aneurysms), and tonsillomedullary zones (16 aneurysms). Neurological and CN morbidity linked to aneurysms in the suprahypoglossal triangle was similar to that associated with aneurysms in the infrahypoglossal triangle, but no morbidity was associated with PICA aneurysms outside the vagoaccessory triangle. A distal PICA origin on angiography localized the aneurysm to the suprahypoglossal triangle in 71% of patients, and distal PICA aneurysms were localized to the infrahypoglossal triangle or outside the vagoaccessory triangle in 78% of patients. Conclusions The anatomical triangles and zones clarify the borders of operative corridors to PICA aneurysms and define the depth of dissection through the CNs. Deep dissection to aneurysms in the anterior medullary zone traverses CNs X, XI, and XII, whereas shallow dissection to aneurysms in the lateral medullary zone traverses CNs X and XI. Posterior inferior cerebellar artery aneurysms outside the vagoaccessory triangle are frequently distal and superficial to the lower CNs, and associated surgical morbidity is minimal. Angiography may preoperatively localize a PICA aneurysm's triangular anatomy based on the distal PICA origin or distal aneurysm location.

Download Full-text

Decision Making in Surgery for Nonsaccular Posterior Inferior Cerebellar Artery Aneurysms With Special Reference to Intraoperative Assessment of Collateral Blood Flow and Neurophysiological Function

Operative Neurosurgery ◽

10.1093/ons/opx141 ◽

2017 ◽

Vol 14 (4) ◽

pp. 422-431 ◽

Cited By ~ 1

Author(s):

Alessandro Narducci ◽

Ran Xu ◽

Peter Vajkoczy

Keyword(s):

Posterior Inferior Cerebellar Artery ◽

Neurophysiological Monitoring ◽

Occipital Artery ◽

Pica Pica ◽

Endovascular Techniques ◽

Vessel Occlusion ◽

Cerebellar Artery ◽

Pica Aneurysms ◽

Intraoperative Test ◽

Time Assessment

Abstract BACKGROUND Posterior inferior cerebellar artery (PICA) aneurysms represent a challenging pathology. PICA sacrifice is often necessary, due to the high proportion of nonsaccular aneurysms that can be found in this location. Several treatments are available, but the infrequency of these aneurysms and the increasing number of endovascular techniques have limited the development of a standardized algorithm for cases in which open surgery is indicated. OBJECTIVE We present our series of nonsaccular PICA aneurysms, in the attempt to define an algorithm for their surgical management. METHODS We retrospectively reviewed the operation database, identifying patients harboring nonsaccular PICA aneurysms who were surgically treated at our institution from 2007 to 2016. RESULTS During a 9-yr period, 17 patients harboring 18 nonsaccular PICA aneurysms were surgically treated at our institution. Fourteen (7.7%) aneurysms were located within the proximal PICA (including those located at the vertebral artery–PICA junction), and 4 were located distally. We performed PICA revascularization in 8 (57.1%) cases of proximal aneurysms (n = 4, PICA–PICA bypass; n = 4, occipital artery–PICA bypass). We based our decision whether to perform bypass on intraoperative test occlusion with indocyanine green (ICG) videoangiography and neurophysiological monitoring. In no cases, bypass was necessary for distal aneurysms. CONCLUSION For nonsaccular PICA aneurysms, in which vessel occlusion is often necessary, it is possible to adopt a selective use of revascularization techniques. Intraoperative occlusion test with ICG videoangiography and neurophysiological monitoring provides reliable indications, allowing real-time assessment of collateral circulation.

Download Full-text

Distal posterior inferior cerebellar artery aneurysm in a child

Arquivos de Neuro-Psiquiatria ◽

10.1590/s0004-282x1992000200019 ◽

1992 ◽

Vol 50 (2) ◽

pp. 229-233 ◽

Cited By ~ 1

Author(s):

J. Francisco Salomão ◽

René D. Leibinger ◽

Yara M. S. Lima Ciro de A. Cunha ◽

Ilton G. Shinzato ◽

Paulo de T. L. Dantas

Keyword(s):

Subarachnoid Hemorrhage ◽

Intracranial Aneurysms ◽

Posterior Inferior Cerebellar Artery ◽

Artery Aneurysm ◽

Rare Occurrence ◽

Cerebellar Artery ◽

Low Incidence ◽

Pica Aneurysms

The case of a 7-year-old boy presenting with recurrent episodes of subarachnoid hemorrhage due to a distal posterior inferior cerebellar artery aneurysm (PICA), successfully operated, is reported.' The low incidence of intracranial aneurysms in the first decade of life and the rare occurrence of distal PICA aneurysms are unusual features of this case. The theories regarding the origin of intracranial berry aneurysms are discussed.

Download Full-text

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.

Download Full-text

Isolated abducens nerve palsy associated with subarachnoid hemorrhage: a localizing sign of ruptured posterior inferior cerebellar artery aneurysms

Journal of Neurosurgery ◽

10.3171/2017.2.jns162951 ◽

2018 ◽

Vol 128 (6) ◽

pp. 1830-1838 ◽

Cited By ~ 2

Author(s):

Jan-Karl Burkhardt ◽

Ethan A. Winkler ◽

George F. Lasker ◽

John K. Yue ◽

Michael T. Lawton

Keyword(s):

Subarachnoid Hemorrhage ◽

Cranial Nerve ◽

Posterior Inferior Cerebellar Artery ◽

Artery Aneurysm ◽

Abducens Nerve ◽

Dorello’S Canal ◽

Ruptured Aneurysms ◽

Fisher Grade ◽

Cerebellar Artery ◽

Pica Aneurysms

OBJECTIVECompressive cranial nerve syndromes can be useful bedside clues to the diagnosis of an enlarging intracranial aneurysm and can also guide subsequent evaluation, as with an acute oculomotor nerve (cranial nerve [CN] III) palsy that is presumed to be a posterior communicating artery aneurysm and a surgical emergency until proven otherwise. The CN VI has a short cisternal segment from the pontomedullary sulcus to Dorello’s canal, remote from most PICA aneurysms but in the hemodynamic pathway of a rupturing PICA aneurysm that projects toward Dorello’s canal. The authors describe a cranial nerve syndrome for posterior inferior cerebellar artery (PICA) aneurysms that associates subarachnoid hemorrhage (SAH) and an isolated abducens nerve (CN VI) palsy.METHODSClinical and radiological data from 106 surgical patients with PICA aneurysms (66 ruptured and 40 unruptured) were retrospectively reviewed. Data from a group of 174 patients with other aneurysmal SAH (aSAH) were analyzed in a similar manner to control for nonspecific effects of SAH. Univariate statistical analysis compared incidence and risk factors associated with CN VI palsy in subarachnoid hemorrhage.RESULTSOverall, 13 (4.6%) of 280 patients had CN VI palsy at presentation, and all of them had ruptured aneurysms (representing 13 [5.4%] of the 240 cases of ruptured aneurysms). CN VI palsies were observed in 12 patients with ruptured PICA aneurysms (12/66 [18.1%]) and 1 patient with other aSAH (1/174 [0.1%], p < 0.0001). PICA aneurysm location in ruptured aneurysms was an independent predictor for CN VI palsy on multivariate analysis (p = 0.001). PICA aneurysm size was not significantly different in patients with or without CN VI palsy (average size 4.4 mm and 5.2 mm, respectively). Within the PICA aneurysm cohort, modified Fisher grade (p = 0.011) and presence of a thick cisternal SAH (modified Fisher Grades 3 and 4) (p = 0.003) were predictors of CN VI palsy. In all patients with ruptured PICA aneurysms and CN VI palsy, dome projection and presumed direction of rupture were directed toward the ipsilateral and/or contralateral Dorello’s canal, in agreement with laterality of the CN palsy. In patients with bilateral CN VI palsies, a medial projection with extensive subarachnoid blood was observed near bilateral canals.CONCLUSIONSThis study establishes a localizing connection between an isolated CN VI palsy, SAH, and an underlying ruptured PICA aneurysm. CN VI palsy is an important clinical sign in aSAH and when present on initial clinical presentation may be assumed to be due to ruptured PICA aneurysms until proven otherwise. The deficit may be ipsilateral, contralateral, or bilateral and is determined by the direction of the aneurysm dome projection and extent of subarachnoid bleeding toward Dorello’s canal, rather than by direct compression.

Download Full-text

An a3-Anterior Inferior Cerebellar Artery to p3-Posterior Inferior Cerebellar Artery Bypass With Thrombectomy and Trapping of an Anterior Inferior Cerebellar Artery Aneurysm: 3-Dimensional Operative Video

Operative Neurosurgery ◽

10.1093/ons/opaa014 ◽

2020 ◽

Vol 19 (3) ◽

pp. E311-E312

Author(s):

Justin R Mascitelli ◽

Sirin Gandhi ◽

Jacob F Baranoski ◽

Michael J Lang ◽

Michael T Lawton

Keyword(s):

Artery Bypass ◽

Posterior Inferior Cerebellar Artery ◽

Cranial Nerves ◽

Artery Aneurysm ◽

Anterior Inferior Cerebellar Artery ◽

Occipital Artery ◽

Cerebellar Artery ◽

Retrograde Filling ◽

In Situ Bypass

Abstract In situ bypasses to the anterior inferior cerebellar artery (AICA) are unusual because, with only one artery in the cerebellopontine angle (CPA), no natural intracranial donors parallel its course. In rare cases, the posterior inferior cerebellar artery (PICA) may have the tortuosity or redundancy to be mobilized to the AICA to serve as a donor. This video demonstrates this p3 PICA-to-a3 AICA in situ side-to-side bypass. A 75-yr-old woman presented with ataxia and hemiparesis from a large thrombotic right AICA aneurysm compressing the brainstem. Strategy consisted of bypass, trapping, and brainstem decompression. Written informed consent for surgery was obtained from the patient. A hockey-stick incision was made to harvest the occipital artery as a backup donor, but its diminutive caliber precluded its use. The bypass was performed through an extended retrosigmoid craniotomy. The aneurysm was trapped completely and thrombectomized to relieve the pontine mass effect. Indocyanine green videoangiography confirmed patency of the bypass, retrograde filling of the AICA to supply pontine perforators, and no residual aneurysmal filling. This unusual in situ bypass is possible when redundancy of the AICA and PICA allow their approximation in the CPA. The anastomosis is performed lateral to the lower cranial nerves in a relatively open and superficial plane. The extended retrosigmoid approach provides adequate exposure for both the bypass and aneurysm trapping. In situ AICA-PICA bypass enables anterograde and retrograde AICA revascularization with side-to-side anastomosis. The occipital artery-to-AICA bypass and the V3 vertebral artery-to-AICA interpositional bypass are alternatives when intracranial anatomy is unfavorable for this in situ bypass.1–6 Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

Download Full-text