The Glossopharyngo-Cochlear Triangle—Part I: Quantitative Anatomic Analysis of High-Riding Posterior Inferior Cerebellar Artery Aneurysms Exposed Through the Extended Retrosigmoid Approach

2020 ◽  
Author(s):  
Xiaochun Zhao ◽  
Ali Tayebi Meybodi ◽  
Komal Naeem ◽  
Evgenii Belykh ◽  
Mohamed A Labib ◽  
...  
Keyword(s):  
Patient Selection ◽  
Posterior Inferior Cerebellar Artery ◽  
Spatial Relationship ◽  
Abducens Nerve ◽  
Foramen Magnum ◽  
Retrosigmoid Approach ◽  
Vertebrobasilar System ◽  
Cerebellar Artery ◽  
The Mean ◽  
Pica Aneurysms

Abstract BACKGROUND An extended retrosigmoid approach can offer sufficient space for clip reconstruction of some high-riding posterior inferior cerebellar artery (PICA) aneurysms. OBJECTIVE To quantitatively investigate the glossopharyngo-cochlear triangle (GCT) and anatomic structures within it. METHODS Extended retrosigmoid craniotomies were performed on 10 sides of cadaveric heads, and the GCT was identified in each specimen. The length of the base and the area of the GCT were measured. The depth of the vertebrobasilar system and the abducens nerve to the GCT were measured. The proximal and distal exposable and controllable points on the vertebrobasilar system were identified. Two imaging-based patient selection algorithms are provided using the lengths from those points to the vertebral artery dural entry point and the superoinferior distances from those points to the inferior edge of the foramen magnum. Other factors related to accessibility via the GCT were investigated. RESULTS The mean (standard deviation [SD]) area of the GCT was 45.7 (12.55) mm2. The mean (SD) depth of the abducens nerve was 14.3 (1.42) mm. The mean (SD) superoinferior distances from the foramen magnum to those points were 23.1 (7.39), 24.7 (8.25), 30.0 (9.56), and 32.6 (7.79) mm, respectively. The lower segment of the vertebrobasilar system was more superficial in the setting of a high-lying vertebrobasilar junction (VBJ) than a low-lying VBJ. CONCLUSION We describe the GCT in an extended retrosigmoid approach for high-riding PICA aneurysms and evaluate the spatial relationship of the neurovascular structures within it. Two potential algorithms are offered for preoperative patient selection.

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

2018 ◽  
Vol 128 (6) ◽  
pp. 1830-1838 ◽  
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.

Aneurysms of the posterior inferior cerebellar artery

1983 ◽  
Vol 58 (3) ◽  
pp. 381-387 ◽  
Author(s):  
Rroger J. Hudgins ◽  
Arthur L. Day ◽  
Ronald G. Quisling ◽  
Albert L. Rhoton ◽  
George W. Sypert ◽  
...  
Keyword(s):  
Posterior Inferior Cerebellar Artery ◽  
Vascular Anomaly ◽  
Foramen Magnum ◽  
Parent Vessel ◽  
Content Type ◽  
Aneurysm Neck ◽  
Suboccipital Craniectomy ◽  
Cerebellar Artery ◽  
Pica Aneurysms ◽  
Fine Print

✓ The clinical and anatomical features of 21 surgically treated saccular aneurysms of the posterior inferior cerebellar artery (PICA) are analyzed. Seventeen of these lesions originated from the PICA-vertebral junction, and four arose from distal PICA branching sites. Twelve lesions arose from the left PICA, nine were right-sided, and all were small (less than 12.5 mm). Most of these aneurysms occurred in females (16 of 21) and presented as classic subarachnoid hemorrhage. The lack of specific focal deficits prevented an accurate pre-angiographic determination of aneurysm location in most instances. Clinically significant vasospasm and aneurysm multiplicity occurred with approximately equal frequency as at other locations. The angiographic and surgical features of these lesions are determined by the course of the vertebral artery and PICA; that is, they occur at branching sites and at curves in the parent vessel, and point in the direction in which flow would have continued if the curve at the aneurysm's origin had not been present. Aneurysms at the PICA-vertebral junction usually occur at least 1 cm above the foramen magnum level, arise distal to the PICA origin in the angle between the two vessels, and are best approached by a paramedian incision with the patient in the lateral recumbent position. Isolated clipping of the aneurysm neck is essential in this instance, as trapping may compromise vital perforating arteries of the brain stem. More distal (retromedullary) PICA aneurysms are sometimes associated with another vascular anomaly (two cases in this series), and are best handled through a bilateral suboccipital craniectomy. Clipping of the neck is the preferred treatment, but trapping is usually safe, if necessary.

Remote distal outflow occlusion: a novel treatment option for complex dissecting aneurysms of the posterior inferior cerebellar artery

2009 ◽  
Vol 111 (1) ◽  
pp. 78-83 ◽  
Author(s):  
Eric S. Nussbaum ◽  
Michael T. Madison ◽  
James K. Goddard ◽  
Jeffrey P. Lassig ◽  
Tariq M. Janjua ◽  
...  
Keyword(s):  
Posterior Inferior Cerebellar Artery ◽  
Novel Treatment ◽  
Cerebellar Artery ◽  
Aneurysmal Dilation ◽  
History Of ◽  
The Mean ◽  
Pica Aneurysms ◽  
Lost To Follow Up ◽  
Dissecting Aneurysms

The authors report a novel management option for patients with complex dissecting aneurysms of the posterior inferior cerebellar artery (PICA). The authors reviewed the medical records and neuroimaging studies of 3 patients who underwent a novel surgical treatment for complicated dissecting PICA aneurysms. The mean follow-up period was 1.1 years, and no patient was lost to follow-up. Two patients were in poor condition following an acute, severe subarachnoid hemorrhage, and 1 presented with headaches and a remote history of bleeding. All patients underwent surgical occlusion of the PICA beyond the tonsillar loop, distal to the aneurysmal segment. Intraoperative and delayed follow-up angiography demonstrated progressive diminution in size of the aneurysmal dilation but persistent filling of the proximal PICA segments supplying the brainstem. Outcome was good in all cases. This novel technique has been used successfully in 3 cases and, to the authors' knowledge, has not been reported previously.

Extracranial Posterior Inferior Cerebellar Artery Aneurysm Causing Isolated Intraventricular Hemorrhage: A Case Report

Neurosurgery ◽  
1988 ◽  
Vol 23 (6) ◽  
pp. 774-777 ◽  
Author(s):  
Antonio Ruelle ◽  
Paolo Cavazzani ◽  
Giancarlo Andrioli
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Intraventricular Hemorrhage ◽  
Posterior Inferior Cerebellar Artery ◽  
Artery Aneurysm ◽  
Foramen Magnum ◽  
Computed Tomographic ◽  
Left Posterior ◽  
Cerebellar Artery ◽  
Computed Tomographic Scan ◽  
Pica Aneurysms

Abstract The authors report the unusual case of an aneurysm arising on an extracranial loop of the left posterior inferior cerebellar artery (PICA). The computed tomographic scan showed an isolated hemorrhage in the lateral ventricles, and the lesion was recognized 1.5 cm below the foramen magnum at the level of the atlas. The literature concerning peripheral PICA aneurysms is reviewed and the clinical and radiological features of these lesions are discussed. A tendency for subarachnoid bleeding from distal PICA aneurysm ruptures to spread into the ventricular system is suggested. The diagnosis of distal PICA aneurysm should also be considered in cases of isolated intraventricular hemorrhage without obvious parenchymal or subarachnoid hemorrhage. The need for four-vessel angiography when studying patients suffering from a subarachnoid hemorrhage is stressed.

scholarly journals Extracranially located PICA aneurysm presenting with supratentorial IVH: A rare event with diagnostic pitfalls

2013 ◽  
Vol 04 (S 01) ◽  
pp. S99-S101
Author(s):  
Amey Savardekar ◽  
Manoj Kumar Tewari ◽  
Rajeev Garg ◽  
Vivek Gupta ◽  
Chirag Ahuja
Keyword(s):  
Posterior Inferior Cerebellar Artery ◽  
Rare Event ◽  
Brain Magnetic Resonance Imaging ◽  
Foramen Magnum ◽  
Sudden Onset ◽  
Proximal Segment ◽  
Suboccipital Craniectomy ◽  
Cerebellar Artery ◽  
Magnetic Resonance Imaging Mri ◽  
Pica Aneurysms

ABSTRACTExtracranially located posterior inferior cerebellar artery (PICA) aneurysms are rare with only 21 cases reported till date. They may arise either from the proximal segment of an extracranially originating PICA or from the tip of its caudal loop when it dips below the foramen magnum. A 16-year-old female presenting with sudden onset severe headache and intraventricular hemorrhage (IVH) in the occipital horns of the lateral ventricle and the fourth ventricles, was diagnosed to have an extracranial proximal segment PICA aneurysm on a four vessel digital subtraction angiography (DSA), after initially missing it on the brain magnetic resonance imaging (MRI) with angiogram (MRA) because of its extracranial location. During surgery, the aneurysm was clipped following a far lateral suboccipital craniectomy with C1‑C2 hemilaminectomy. The patient showed good recovery. Thus, we emphasize the need for a dedicated four vessel angiography to diagnose such lesions.

The Glossopharyngo-Cochlear Triangle—Part II: Case Series Highlighting the Clinical Application to High-Riding Posterior Inferior Cerebellar Artery Aneurysms Exposed Through the Extended Retrosigmoid Approach

2020 ◽  
Author(s):  
Jacob F Baranoski ◽  
Stefan W Koester ◽  
Colin J Przybylowski ◽  
Xiaochun Zhao ◽  
Joshua S Catapano ◽  
...  
Keyword(s):  
Posterior Inferior Cerebellar Artery ◽  
Internal Auditory Canal ◽  
Case Series ◽  
Jugular Foramen ◽  
Foramen Magnum ◽  
Aneurysm Neck ◽  
Cerebellar Artery ◽  
Vertebrobasilar Junction ◽  
Surgical Corridor ◽  
Pica Aneurysms

Abstract BACKGROUND Use of the far lateral transcondylar (FL) approach and vagoaccessory triangle is the standard exposure for clipping most posterior inferior cerebellar artery (PICA) aneurysms. However, a distal PICA origin or high-lying vertebrobasilar junction can position the aneurysm beyond the vagoaccessory triangle, making the conventional FL approach inappropriate. OBJECTIVE To demonstrate the utility of the extended retrosigmoid (eRS) approach and a lateral trajectory through the glossopharyngo-cochlear triangle as the surgical corridor for these cases. METHODS High-riding PICA aneurysms treated by microsurgery were retrospectively reviewed, comparing exposure through the eRS and FL approaches. Clinical, surgical, and outcome measures were evaluated. Distances from the aneurysm neck to the internal auditory canal (IAC), jugular foramen, and foramen magnum were measured. RESULTS Six patients with PICA aneurysms underwent clipping using the eRS approach; 5 had high-riding PICA aneurysms based on measurements from preoperative computed tomography angiography (CTA). Mean distances of the aneurysm neck above the foramen magnum, below the IAC, and above the jugular foramen were 27.0 mm, 3.7 mm, and 8.2 mm, respectively. Distances were all significantly lower versus the comparison group of 9 patients with normal or low-riding PICA aneurysms treated using an FL approach (P &lt; .01). All 6 aneurysms treated using eRS were completely occluded without operative complications. CONCLUSION The eRS approach is an important alternative to the FL approach for high-riding PICA aneurysms, identified as having necks more than 23 mm above the foramen magnum on CTA. The glossopharyngo-cochlear triangle is another important anatomic triangle that facilitates microsurgical dissection.

Hemifacial Spasm: Endoscopic Vascular Decompression

1997 ◽  
Vol 117 (4) ◽  
pp. 308-314 ◽  
Author(s):  
J. Magnan ◽  
F. Caces ◽  
P. Locatelli ◽  
A. Chays
Keyword(s):  
Hemifacial Spasm ◽  
Marked Improvement ◽  
Cerebellopontine Angle ◽  
Posterior Inferior Cerebellar Artery ◽  
Endoscopic Examination ◽  
Anterior Inferior Cerebellar Artery ◽  
Cerebellar Artery ◽  
The Mean ◽  
Vascular Decompression

Sixty patients with primitive hemifacial spasm were treated by means of a minimally invasive retrosigmoid approach in which endoscopic and microsurgical procedures were combined. Intraoperative endoscopic examination of the cerebellopontine angle showed that for 56 of the patients vessel-nerve conflict was the cause of hemifacial spasm. The most common offending vessel was the posterior inferior cerebellar artery (39 patients), next was the vertebral artery (23 patients), and last was the anterior inferior cerebellar artery (16 patients). Nineteen of the patients had multiple offending vascular loops. In one patient, another cause of hemifacial spasm was an epidermoid tumor of the cerebellopontine angle. For three patients, it was not possible to determine the exact cause of the facial disorder. Follow-up information was reviewed for 54 of 60 patients; the mean follow-up period was 14 months. Fifty of the patients were in the vessel-nerve conflict group. Forty of the 50 were free of symptoms, and four had marked improvement. The overall success rate was 88%, and there was minimal morbidity (no facial palsy, two cases of severe hearing loss).

Endovascular Surgery for Proximal Posterior Inferior Cerebellar Artery Aneurysms: An Analysis of Glasgow Outcome Score by Hunt-Hess Grades

Neurosurgery ◽  
2006 ◽  
Vol 58 (4) ◽  
pp. 619-625 ◽  
Author(s):  
Robert A. Mericle ◽  
Adam S. Reig ◽  
Matthew V. Burry ◽  
Eric Eskioglu ◽  
Christopher S. Firment ◽  
...  
Keyword(s):  
Posterior Inferior Cerebellar Artery ◽  
Endovascular Surgery ◽  
Glasgow Outcome Score ◽  
Clinical Grade ◽  
Outcome Score ◽  
Fisher Grade ◽  
Cerebellar Artery ◽  
Pica Aneurysms ◽  
Angiographic Result

Abstract OBJECTIVE: Proximal posterior inferior cerebellar artery (PICA) aneurysms represent a subset of posterior circulation aneurysms that can be routinely treated with either clipping or coiling. The literature contains limited numbers of patients with proximal PICA aneurysms treated with endovascular surgery. We report our experience with endovascular surgery of proximal PICA aneurysms with emphasis on patients with poor Hunt-Hess grades. METHODS: We reviewed 31 consecutive patients with proximal PICA aneurysms who were treated with endovascular surgery. The following data were analyzed: age, sex, size of aneurysm, Hunt-Hess grade at presentation, Fisher grade at presentation, angiographic result after embolization, complications, number of days hospitalized, duration of follow-up, angiographic follow-up results, and Glasgow Outcome Score at follow-up. RESULTS: Excellent angiographic occlusion was achieved in 30 of 31 (97%) patients. Clinical follow-up with Glasgow Outcome Score was performed on every patient an average of 10 months later. Twenty-one of 31 (68%) patients had good outcomes (Glasgow Outcome Score I or II) at follow-up. Of the patients who presented with a favorable clinical grade (Hunt-Hess 0–III), 13 of 15 (87%) had good outcomes at follow-up. Of the patients who presented with a poor clinical grade (Hunt-Hess Grade IV or higher), 8 of 16 (50%) had good outcomes at follow-up. CONCLUSION: This series demonstrates the safety and efficacy of endovascular surgery for proximal PICA aneurysms. Many patients with poor Hunt-Hess grades from ruptured PICA aneurysms ultimately had a good outcome. This could be secondary to early, aggressive treatment of hydrocephalus and the minimally invasive nature of the endovascular approach.

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

2017 ◽  
Vol 13 (5) ◽  
pp. 586-595 ◽  
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.

Endovascular sacrifice of the proximal posterior inferior cerebellar artery for treatment of ruptured intracranial aneurysms

2020 ◽  
Vol 12 (8) ◽  
pp. 777-782
Author(s):  
James G Malcolm ◽  
Jonathan A Grossberg ◽  
Nealen G Laxpati ◽  
Ali Alawieh ◽  
Frank C Tong ◽  
...  
Keyword(s):  
Posterior Inferior Cerebellar Artery ◽  
High Morbidity ◽  
Brainstem Compression ◽  
Cerebellar Artery ◽  
Diseased Segment ◽  
Suboccipital Decompression ◽  
Pica Aneurysms ◽  
Ruptured Intracranial Aneurysms ◽  
Dissecting Aneurysms

BackgroundRuptured aneurysms of the intracranial vertebral artery (VA) or posterior inferior cerebellar artery (PICA) are challenging to treat as they are often dissecting aneurysms necessitating direct sacrifice of the diseased segment, which is thought to carry high morbidity due to brainstem and cerebellar stroke. However, relatively few studies evaluating outcomes following VA or proximal PICA sacrifice exist. We sought to determine the efficacy and outcomes of endovascular VA/PICA sacrifice.MethodsA retrospective series of ruptured VA/PICA aneurysms treated by endovascular sacrifice of the VA (including the PICA origin) or proximal PICA is reviewed. Collected data included demographic, radiologic, clinical, and disability information.ResultsTwenty-one patients were identified. Median age was 57 years (IQR 11); 15 were female. The Hunt and Hess grade was mostly 3 and 4 (18/21). Seven cases (33%) involved VA-V4 at the PICA take-off, and 14 cases (67%) involved the PICA exclusively. For VA pathology, V4 was sacrificed in all cases, while for PICA pathology, sacrificed segments included anterior medullary (4/14), lateral medullary (7/14), and tonsillomedullary (3/14) segments. Four patients went to hospice (19%). Twelve patients (57%) had evidence of stroke on follow-up imaging: cerebellar (8), medullary (1), and both (3). One patient required suboccipital decompression for brainstem compression. No aneurysm re-rupture occurred. Median discharge modified Rankin Scale score was 2.0 (IQR 2), which decreased to 1.0 (IQR 1) at median follow-up of 6.5 months (IQR 23).ConclusionsEndovascular sacrifice of V4 or PICA aneurysms may carry less morbidity than previously thought, and is a viable alternative for poor surgical candidates or those with good collateral perfusion.

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