Microsurgical Anatomy of the Meningeal Branch of the Dorsolateral Medullary Plexus

2019 ◽  
Author(s):  
Ali Tayebi Meybodi ◽  
Xiaochun Zhao ◽  
Leandro Borba Moreira ◽  
Mark C Preul ◽  
Lea M Alhilali ◽  
...  
Keyword(s):  
Anatomic Variation ◽  
Posterior Inferior Cerebellar Artery ◽  
Microsurgical Anatomy ◽  
Anatomical Features ◽  
Arteriovenous Fistulas ◽  
Cerebellar Artery ◽  
Dural Arteriovenous Fistulas ◽  
Far Lateral ◽  
Meningeal Tumors ◽  
Actual Prevalence

Abstract BACKGROUND Meningeal branches originating from intradural arteries may be involved in several diseases such as meningeal tumors and arteriovenous lesions. These “pial-dural” arterial connections have been described for anterior cerebral, posterior cerebral, and cerebellar arteries. However, to the best of our knowledge, meningeal supply originating from the arterial plexus over the dorsolateral aspect of the medulla oblongata (dorsolateral medullary plexus [DLMP]) has not been described. OBJECTIVE To define the microsurgical anatomy of the meningeal branch of DLMP. METHODS A total of 20 cadaver heads (40 sides) underwent far-lateral craniotomy and the cerebellomedullary cisterns were explored to find the DLMP and any meningeal branches. Additionally, de-identified intraoperative images of 85 patients with vertebral artery (VA)/posterior inferior cerebellar artery aneurysms who had undergone far-lateral craniotomy were studied to find any meningeal branches of DLMP. RESULTS The meningeal branches of DLMP were identified in 4 cadavers/sides. These branches reached the region of jugular tubercle (JT) after crossing the accessory nerve. In 3 specimens, these branches were joined by a small twig from V4-VA before penetrating the dura. DLMP meningeal branches were found in 12 patients of the studied cohort (14%) with similar anatomical features as those found in the cadaveric study. CONCLUSION DLMP may give rise to meningeal branches to the adjacent dura of JT. The actual prevalence of this anatomic variation is difficult to estimate using our data. However, when present, these branches may have important clinical implications, ie, diseases such as dural arteriovenous fistulas, pial arteriovenous malformations (AVMs), and meningeal-based tumors.

Microsurgical anatomy of the posterior spinal artery via a far-lateral transcondylar approach

2009 ◽  
Vol 10 (3) ◽  
pp. 228-233 ◽  
Author(s):  
Hakan Seçkin ◽  
Özkan Ateş ◽  
Andrew M. Bauer ◽  
Mustafa K. Başkaya
Keyword(s):  
Posterior Inferior Cerebellar Artery ◽  
Lateral Approach ◽  
Microsurgical Anatomy ◽  
Posterior Spinal Artery ◽  
Transcondylar Approach ◽  
Cerebellar Artery ◽  
Far Lateral Approach ◽  
Close Proximity ◽  
Far Lateral ◽  
Clinically Significant

Object The posterior spinal artery (PSA) is a clinically significant vessel that may frequently be encountered during the far-lateral transcondylar approach. There have been a limited number of reports on the specific origin of the PSA in the literature. The aim of this study was to demonstrate the origin of the PSA. Methods Thirteen cadaveric heads (26 sides) were injected with colored silicon. A bilateral far-lateral transcondylar approach was performed on each side. In every specimen the site of the origin of the PSAs, as well as their course, branching pattern and anastomoses, external diameters, and neighboring vascular and nervous structures were recorded. Microanatomical dissections were performed using the surgical microscope. In addition, 8 surgical cases in which the far-lateral approach was used were collected prospectively to record the course and origin of the PSA. Altogether, a total of 34 sides were analyzed for their PSA origin and course. Results In the cadaveric specimens, the PSA was found to originate from the vertebral artery (VA) in 25 sides (96%). In 13 specimens (50%) the PSA originated from the V4 segment of the VA intradurally. In 12 specimens (46%) the PSA originated from the V3 segment of the VA extradurally. In 1 specimen (4%), in whom the posterior inferior cerebellar artery (PICA) had an early origin from the VA extradurally at the C-1 level, the PSA originated from the PICA. Of the 8 surgical cases, 2 patients had extradural origin of the PSA from the V3 segment of the VA, whereas 6 patients had intradural origin of the PSA from the V4 segment. Conclusions Although the usual origin of the PSA is from the VA either intra- or extradurally, its origin is closely related to the origin of the PICA. The PSA originates from the PICA in cases in which the PICA originates extradurally from the VA. In the far-lateral transcondylar approach, the dura is opened in close proximity to the VA. Knowledge of the origin and course of the PSA is critically important when executing the far-lateral approach to avoid its injury.

scholarly journals Far Lateral Approach for Clipping of a Posterior Inferior Cerebellar Artery Aneurysm

2019 ◽  
Vol 80 (S 04) ◽  
pp. S343-S343
Author(s):  
Jaafar Basma ◽  
Vincent N. Nguyen ◽  
William M. Mangham ◽  
Nickalus R. Khan ◽  
Jeffrey Sorenson ◽  
...  
Keyword(s):  
Hypoglossal Nerve ◽  
Posterior Inferior Cerebellar Artery ◽  
Artery Aneurysm ◽  
Lateral Approach ◽  
Microsurgical Anatomy ◽  
Microsurgical Clipping ◽  
Cerebellar Artery ◽  
Far Lateral Approach ◽  
Far Lateral ◽  
Clip Occlusion

Abstract Objectives To describe a far lateral approach for microsurgical clipping of a ruptured posterior inferior cerebellar artery (PICA) aneurysm involving the hypoglossal nerve, with emphasis on the microsurgical anatomy, and technique. Design A far lateral craniotomy is performed in the lateral decubitus position and the transverse and sigmoid sinuses were exposed. After opening the dura, sutures are placed to allow gentle mobilization of the sinuses. The ipsilateral cerebellar tonsil is mobilized and the PICA is followed to its junction with the vertebral artery. Hypoglossal nerve rootlets are draped over the dome of the aneurysm. Mobilization of the PICA and the hypoglossal nerve away from the lateral medulla allows microsurgical clipping of the aneurysm neck. Photographs of the region are borrowed from Dr Rhoton's laboratory to illustrate the microsurgical anatomy. Participants The senior authors performed the surgery. The video was edited by Drs. V.N. and J.B. Chart review and literature review were performed by Drs. W.M. and J.B. Outcome Measures Outcome was assessed with successful clip occlusion and postoperative neurological function. Results There was complete clip occlusion of the PICA aneurysm with no postoperative neurological deficits. The patient was discharged home after an uneventful hospital course. Conclusion The far lateral approach provides an adequate corridor to the ventrolateral brainstem for microsurgical treatment of PICA aneurysms. An adequate understanding of the relevant microsurgical anatomy is the key to safe and effective clipping in this region.The link to the video can be found at: https://youtu.be/yhjKRIG5H74.

scholarly journals The role of alternative anastomosis sites in occipital artery–posterior inferior cerebellar artery bypass in the absence of the caudal loop using the far-lateral approach

2017 ◽  
Vol 126 (2) ◽  
pp. 634-644 ◽  
Author(s):  
Hitoshi Fukuda ◽  
Alexander I. Evins ◽  
Koichi Iwasaki ◽  
Itaro Hattori ◽  
Kenichi Murao ◽  
...  
Keyword(s):  
Posterior Fossa ◽  
Posterior Inferior Cerebellar Artery ◽  
Technical Difficulty ◽  
Foramen Magnum ◽  
Lateral Approach ◽  
Difficulty Level ◽  
Occipital Artery ◽  
Cerebellar Artery ◽  
Far Lateral Approach ◽  
Far Lateral

OBJECTIVE Occipital artery–posterior inferior cerebellar artery (OA-PICA) bypass is a technically challenging procedure for posterior fossa revascularization. The caudal loop of the PICA is considered the optimal site for OA-PICA anastomosis, however its absence can increase the technical difficulty associated with this procedure. The use of the far-lateral approach for accessing alternative anastomosis sites in OA-PICA bypass in patients with absent or unavailable caudal loops of PICA is evaluated. METHODS A morphometric analysis of OA-PICA bypass with anastomosis on each segment of the PICA was performed on 5 cadaveric specimens through the conventional midline foramen magnum and far-lateral approaches. The difficulty level associated with anastomoses at each segment was qualitatively assessed in each approach for exposure and maneuverability by multiple surgeons. A series of 8 patients who underwent OA-PICA bypass for hemodynamic ischemia or ruptured dissecting posterior fossa aneurysms are additionally reviewed and described, and the clinical significance of the caudal loop of PICA is discussed. RESULTS Anastomosis on the caudal loop could be performed more superficially than on any other segment (p < 0.001). A far-lateral approach up to the medial border of the posterior condylar canal provided a 13.5 ± 2.2–mm wider corridor than the conventional midline foramen magnum approach, facilitating access to alternative anastomosis sites. The far-lateral approach was successfully used for OA-PICA bypass in 3 clinical cases whose caudal loops were absent, whereas the midline foramen magnum approach provided sufficient exposure for caudal loop bypass in the remaining 5 cases. CONCLUSIONS The absence of the caudal loop of the PICA is a major contributing factor to the technical difficulty of OA-PICA bypass. The far-lateral approach is a useful surgical option for OA-PICA bypass when the caudal loop of the PICA is unavailable.

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

2005 ◽  
Vol 19 (2) ◽  
pp. 1-5 ◽  
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.

scholarly journals Surgical microanatomy of the occipital artery for suboccipital muscle dissection and intracranial artery reconstruction

2019 ◽  
Vol 10 ◽  
pp. 127
Author(s):  
Yuto Hatano ◽  
Nakao Ota ◽  
Kosumo Noda ◽  
Yasuaki Okada ◽  
Yosuke Suzuki ◽  
...  
Keyword(s):  
Anatomic Variation ◽  
Superficial Temporal Artery ◽  
Posterior Inferior Cerebellar Artery ◽  
Temporal Artery ◽  
Occipital Artery ◽  
Cerebellar Artery ◽  
Preoperative Ct ◽  
Running Pattern ◽  
Enhanced Computed Tomography ◽  
Artery Reconstruction

Background: The occipital artery (OA) is an important donor artery for posterior fossa revascularization. Harvesting the OA is difficult in comparison to the superficial temporal artery because the OA runs between suboccipital muscles. Anatomical knowledge of the suboccipital muscles and OA is essential for harvesting the OA during elevation of the splenius capitis muscle (SPL) for reconstruction of the posterior inferior cerebellar artery. We analyzed the running pattern of the OA and its anatomic variations using preoperative and intraoperative findings. Methods: From April 2012 to March 2018, we surgically treated 162 patients with suboccipital muscle dissection by OA dissection using the lateral suboccipital approach. The running pattern and relationship between the suboccipital muscles and OA were retrospectively analyzed using the operation video and preoperative enhanced computed tomography (CT) images. The anatomic variation in the running pattern of the OA was classified into two types: lateral type, running lateral to the muscle and medial type, running medial to the longissimus capitis muscle (LNG). Results: The medial pattern was observed in 107 (66%) patients and the lateral pattern in 54 (33.3%); 1 (0.6%) patient had the OA running between the LNGs. Conclusion: Preoperative CT is effective in determining the running course of the OA, which is important for safely harvesting the OA during SPL elevation. There is a risk of causing OA injury in patients with the lateral pattern. This is the first report showing that the OA rarely runs in between the LNGs.

scholarly journals Far-lateral approach for surgical treatment of fusiform PICA aneurysm

2015 ◽  
Vol 38 (videosuppl1) ◽  
pp. Video10 ◽  
Author(s):  
William T. Couldwell ◽  
Jayson A. Neil
Keyword(s):  
Evoked Potential ◽  
Posterior Inferior Cerebellar Artery ◽  
Motor Evoked Potential ◽  
Lateral Approach ◽  
Cerebellar Artery ◽  
Far Lateral Approach ◽  
Vessel Patency ◽  
Far Lateral ◽  
Evoked Potential Monitoring ◽  
Pica Aneurysms

Ruptured fusiform posterior inferior cerebellar artery (PICA) aneurysms can be technically challenging lesions. Surgeons must be ready to employ a variety of strategies in the successful treatment of these aneurysms. Strategies include complex clip techniques including clip-wrapping or trapping and revascularization. The case presented here is of a man with subarachnoid hemorrhage from a fusiform ruptured PICA aneurysm. The technique demonstrated is a far-lateral approach and a clip-wrap technique using muslin gauze. The patient was given aspirin preoperatively in preparation for possible occipital–PICA bypass if direct repair was not feasible. It is the authors' preference to perform direct vessel repair as a primary goal and use bypass techniques when this is not possible. Vessel patency was evaluated after clip-wrapping using intraoperative Doppler. Intraoperative somatosensory and motor evoked potential monitoring is used in such cases. The patient recovered well.The video can be found here: http://youtu.be/iwLqufH47Ds.

Microsurgical anatomy of the extracranial—extradural origin of the posterior inferior cerebellar artery

1999 ◽  
Vol 91 (4) ◽  
pp. 645-652 ◽  
Author(s):  
Andrew D. Fine ◽  
Alberto Cardoso ◽  
Albert L. Rhoton
Keyword(s):  
Soft Tissue ◽  
Vertebral Artery ◽  
Posterior Inferior Cerebellar Artery ◽  
Microsurgical Anatomy ◽  
Content Type ◽  
The Third ◽  
Cerebellar Artery ◽  
The Common ◽  
Bone Anomalies ◽  
Fine Print

Object. The authors describe the microsurgical anatomy of the posterior inferior cerebellar artery (PICA) with an extradural origin and discuss its importance as a common variation.Methods. The microsurgical anatomy of paired PICAs with an extradural origin were examined.Conclusions. Five to 20% of PICAs have an extradural origin. In the case described, both PICAs arose extradurally from the third segment of the vertebral artery (VA). Both origins were less than 1 cm proximal to the site at which the VA penetrated the dura, and neither PICA gave rise to extradural branches. Extradurally, the PICAs coursed parallel to the VA and the C-1 nerve and the three structures penetrated the dura together. Intradurally, the PICAs remained lateral and posterior to the brainstem, whereas, in the common PICA configuration, the first segment of the PICA courses anterior to the medulla. Neither PICA sent branches to the anterior brainstem, which is commonly found in PICAs with an intradural origin. There were no soft-tissue or bone anomalies.

Microsurgical Anatomy of the Posterior Inferior Cerebellar Artery

Neurosurgery ◽  
1982 ◽  
Vol 10 (2) ◽  
pp. 170-199 ◽  
Author(s):  
Richard J. Lister ◽  
Albert L. Rhoton ◽  
Toshiom Matsushima ◽  
David A. Peace
Keyword(s):  
Vertebral Artery ◽  
Posterior Inferior Cerebellar Artery ◽  
Cerebellar Tonsil ◽  
Cortical Surface ◽  
Microsurgical Anatomy ◽  
Vagus Nerves ◽  
Adjacent Part ◽  
Tela Choroidea ◽  
Cerebellar Artery ◽  
Superior Pole

Abstract Fifty cerebellar hemispheres from 25 adult cadavers were examined. The posterior inferior cerebellar artery (PICA), by definition, arose from the vertebral artery. The vertebral artery was present in 49 and the PICA was present in 42 of the 50 hemispheres. Forty-one of the 42 PICAs arose as a single trunk and 1 arose as a duplicate trunk. The PICA was divided into five segments: the anterior medullary segment lay on the front of the medulla; the lateral medullary segment coursed beside the medulla and extended to the origin of the glossopharyngeal, vagal, and accessory nerves; the tonsillomedullary segment coursed around the caudal half of the cerebellar tonsil; the telovelotonsillar segment coursed in the cleft between the tela choroidea and the inferior medullary velum rostrally and the superior pole of the cerebellar tonsil caudally; and the cortical segment was distributed to the cerebellar surface. Thirty-seven of the 42 PICAs bifurcated into a medial and a lateral trunk. The medial trunk supplied the vermis and the adjacent part of the hemisphere, and the lateral trunk supplied the cortical surface of the tonsil and the hemisphere. The PICA gave off perforating, choroidal, and cortical arteries. The cortical arteries were divided into vermian, tonsillar, and hemispheric groups. Sixteen of the 42 PICAs passed between the rootlets of the accessory nerve, 10 passed between the rootlets of the vagus nerve, 13 passed between the vagus and the accessory nerves, 2 coursed rostral to the glossopharyngeal nerve, and 1 passed between the glossopharyngeal and the vagus nerves.

Segmental anatomy of cerebellar arteries: a proposed nomenclature

2011 ◽  
Vol 115 (2) ◽  
pp. 387-397 ◽  
Author(s):  
Ana Rodríguez-Hernández ◽  
Albert L. Rhoton ◽  
Michael T. Lawton
Keyword(s):  
Cerebral Arteries ◽  
Posterior Inferior Cerebellar Artery ◽  
Superior Cerebellar Artery ◽  
Anterior Inferior Cerebellar Artery ◽  
Microsurgical Anatomy ◽  
Numbering System ◽  
Segmental Anatomy ◽  
Cerebellar Artery ◽  
Intracranial Arteries

Object The conceptual division of intracranial arteries into segments provides a better understanding of their courses and a useful working vocabulary. Segmental anatomy of cerebral arteries is commonly cited by a numerical nomenclature, but an analogous nomenclature for cerebellar arteries has not been described. In this report, the microsurgical anatomy of the cerebellar arteries is reviewed, and a numbering system for cerebellar arteries is proposed. Methods Cerebellar arteries were designated by the first letter of the artery's name in lowercase letters, distinguishing them from cerebral arteries with the same first letter of the artery's name. Segmental anatomy was numbered in ascending order from proximal to distal segments. Results The superior cerebellar artery was divided into 4 segments: s1, anterior pontomesencephalic segment; s2, lateral pontomesencephalic segment; s3, cerebellomesencephalic segment; and s4, cortical segment. The anterior inferior cerebellar artery was divided into 4 segments: a1, anterior pontine segment; a2, lateral pontine segment; a3, flocculopeduncular segment; and a4, cortical segment. The posterior inferior cerebellar artery was divided into 5 segments: p1, anterior medullary segment; p2, lateral medullary segment; p3, tonsillomedullary segment; p4, telovelotonsillar segment; and p5, cortical segment. Conclusions The proposed nomenclature for segmental anatomy of cerebellar artery complements established nomenclature for segmental anatomy of cerebral arteries. This nomenclature is simple, easy to learn, and practical. The nomenclature localizes distal cerebellar artery aneurysms and also localizes an anastomosis or describes a graft's connections to donor and recipient arteries. These applications of the proposed nomenclature with cerebellar arteries mimic the applications of the established nomenclature with cerebral arteries.

Variations of Occipital Artery-Posterior Inferior Cerebellar Artery Bypass: Anatomic Consideration

2017 ◽  
Vol 14 (5) ◽  
pp. 563-571 ◽  
Author(s):  
Ken Matsushima ◽  
Satoshi Matsuo ◽  
Noritaka Komune ◽  
Michihiro Kohno ◽  
J Richard Lister
Keyword(s):  
Artery Bypass ◽  
Posterior Inferior Cerebellar Artery ◽  
Jugular Foramen ◽  
Occipital Artery ◽  
Parent Artery ◽  
Microsurgical Anatomy ◽  
Main Trunk ◽  
Cerebellar Artery ◽  
Cerebellomedullary Fissure ◽  
Pica Aneurysms

Abstract BACKGROUND Advances in diagnosis of posterior inferior cerebellar artery (PICA) aneurysms have revealed the high frequency of distal and/or dissecting PICA aneurysms. Surgical treatment of such aneurysms often requires revascularization of the PICA including but not limited to its caudal loop. OBJECTIVE To examine the microsurgical anatomy involved in occipital artery (OA)-PICA anastomosis at various anatomic segments of the PICA. METHODS Twenty-eight PICAs in 15 cadaveric heads were examined with the operating microscope to take morphometric measurements and explore the specific anatomy of bypass procedures. RESULTS OA bypass to the p2, p3, p4, or p5 segment was feasible with a recipient vessel of sufficient diameter. The loop wandering near the jugular foramen in the p2 segment provided sufficient length without requiring cauterization of any perforating arteries to the brainstem. Wide dissection of the cerebellomedullary fissure provided sufficient exposure for the examination of some p3 segments and all p4 segments hidden by the tonsil. OA-p5 bypass was placed at the main trunk before the bifurcation in 5 hemispheres and at the larger hemispheric trunk in others. CONCLUSION Understanding the possible variations of OA-PICA bypass may enable revascularization of the appropriate portion of the PICA when the parent artery must be occluded. A detailed anatomic understanding of each segment clarifies important technical nuances for the bypass on each segment. Dissection of the cerebellomedullary fissure helps to achieve sufficient exposure for the bypass procedures on most of the segments.

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