Surgical Anatomy of and Approaches Through the Lateral Foramen Magnum: The Transcondylar Fossa and Transcondylar Approaches

Abstract Background Despite the use of vascularized intranasal flaps, endoscopic endonasal posterior fossa defects remain surgically challenging with high rates of postoperative cerebrospinal fluid leak. Objective The aim of the study is to describe a novel surgical technique that allows complete drilling of the clivus and exposure of the craniovertebral junction with preservation of the nasopharynx. Methods Two formalin-fixed latex-injected anatomical specimens were used to confirm feasibility of the technique. Two surgical approaches were used: sole endoscopic endonasal approach and transnasion approach. The sole endonasal approach was used in a patient with a petroclival meningioma. Results In both anatomical dissections, the inferior clivectomy with exposure of the foramen magnum was achieved with a sole endoscopic endonasal approach. The addition of the transnasion approach helped to complete drilling of the inferior border of the foramen magnum and exposure of the arch of C1. Conclusion This study shows the anatomical feasibility of total clivectomy and exposure of the craniovertebral junction with preservation of the nasopharynx. A more favorable anatomical posterior fossa defect for the reconstruction is achieved with this technique. Further clinical studies are needed to assess if this change would impact the postoperative CSF leak rate.

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Minimally Invasive Direct Transcondylar Approach to the Foramen Magnum: Surgical Anatomy and Presentation of Two Clinical Cases

Journal of Neurological Surgery Part B Skull Base ◽

10.1055/s-0033-1336332 ◽

2013 ◽

Vol 74 (S 01) ◽

Author(s):

Roberto Diaz ◽

Miguel Berbeo ◽

Silvia Oliveros ◽

Juan Acevedo ◽

Oscar Lee ◽

...

Keyword(s):

Minimally Invasive ◽

Foramen Magnum ◽

Surgical Anatomy ◽

Transcondylar Approach ◽

Clinical Cases

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Vertebral Artery Surgery - An Overview of Techniques and Discussion Points for the Future

European Neurological Review ◽

10.17925/enr.2011.06.03.193 ◽

2011 ◽

Vol 6 (3) ◽

pp. 193

Author(s):

Bernard George ◽

Keyword(s):

Vertebral Artery ◽

Jugular Foramen ◽

Craniocervical Junction ◽

Foramen Magnum ◽

Surgical Anatomy ◽

Surgical Approaches ◽

Arteriovenous Fistulas ◽

Intermittent Compression ◽

Safety And Reliability ◽

And Control

The vertebral artery (VA) is an important vessel supplying the hind brain; its surgical exposure and control is usually considered a great challenge. In fact, with good knowledge of surgical anatomy and proper surgical technique, the VA can be controlled and occasionally repaired with safety and reliability. VA exposure is useful in many instances and helps attain better results in the surgical treatment of many different pathologies at any level all along its course in the neck and the skull. These pathologies include intrinsic lesions (atherosclerosis, aneurysms, arteriovenous fistulas), intermittent compression by osteophytes or fibrous bands, and permanent compression mostly by different types of tumours. VA exposure also helps to achieve better treatment of spondylotic myelopathy (by oblique corpectomy) and of tumours at the craniocervical junction, foramen magnum and jugular foramen level. Based on the experience of more than 1,600 surgical approaches, VA surgery is associated with a very limited morbidity and mortality.

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Surgical Anatomy and Morphometric Analysis of the Occipital Condyles and Foramen Magnum

Okajimas Folia Anatomica Japonica ◽

10.2535/ofaj1936.75.6_329 ◽

1999 ◽

Vol 75 (6) ◽

pp. 329-334 ◽

Cited By ~ 15

Author(s):

Mustafa BOZBUGA ◽

Adnan ^|^Ouml;ZT^|^Uuml;RK ◽

B^|^uuml;lent BAYRAKTAR ◽

Zafer ARI ◽

Kayihan SAHINOGLU ◽

...

Keyword(s):

Morphometric Analysis ◽

Foramen Magnum ◽

Surgical Anatomy ◽

Occipital Condyles

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Transmastoid Trautman's Triangle Combined Low Retrosigmoid Approach for Foramen Magnum Meningiomas: Surgical Anatomy and Technical Note

Journal of Neurological Surgery Part B Skull Base ◽

10.1055/s-0040-1713755 ◽

2021 ◽

Author(s):

Guangfu Di ◽

Wei Zhou ◽

Xinyun Fang ◽

Qiang Li ◽

Lean Sun ◽

...

Keyword(s):

Treatment Strategies ◽

Foramen Magnum ◽

Surgical Anatomy ◽

Technical Note ◽

Retrosigmoid Approach ◽

Ventrolateral Medulla ◽

Short Neck ◽

Tonsillar Herniation ◽

Cerebellar Tonsillar Herniation ◽

Cadaver Studies

Abstract Objective This study was aimed to assess the potential of utilizing a transmastoid Trautman's triangle combined low retrosigmoid approach for ventral and ventrolateral foramen magnum meningiomas (FMMs) surgical treatment. Methods We simulated this transmastoid Trautman's triangle combined low retrosigmoid approach using five adult cadaveric heads to explore the associated anatomy in a step-by-step fashion, taking pictures of key positions as appropriate. We then employed this approach in a single overweight patient with a short neck who was suffering from large ventral FMMs and cerebellar tonsillar herniation. Results Through cadaver studies, we were able to confirm that this transmastoid Trautman's triangle combined with low retrosigmoid approach achieves satisfactory cranial nerve and vasculature visualization while also offering a wide view of the whole of the ventrolateral medulla oblongata. We, additionally, have successfully employed this approach to treat a single patient suffering from large ventral FMMs with cerebellar tonsillar herniation. Conclusion This transmastoid Trautman's triangle combined low retrosigmoid approach may represent a complement to treatment strategies for ventral and ventrolateral FMMs, particularly in patients with the potential for limited surgical positioning due to their being overweight, having a short neck and suffering from cerebellar tonsillar herniation.

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Endoscopic Endonasal Transclival Transcondylar Approach for Foramen Magnum Meningiomas

Operative Neurosurgery ◽

10.1227/neu.0000000000001102 ◽

2015 ◽

Vol 12 (2) ◽

pp. 153-162 ◽

Cited By ~ 9

Author(s):

Wei-Hsin Wang ◽

Kumar Abhinav ◽

Eric Wang ◽

Carl Snyderman ◽

Paul A Gardner ◽

...

Keyword(s):

Odontoid Process ◽

Human Head ◽

Foramen Magnum ◽

Surgical Anatomy ◽

Occipital Condyle ◽

Anatomical Landmarks ◽

Endoscopic Endonasal ◽

Medial Condyle ◽

Anterior Arch ◽

Surgical Corridor

Abstract BACKGROUND The endoscopic endonasal approach provides a direct route to ventral foramen magnum (FM) lesions like meningiomas, which are difficult to access. Endonasal access at the FM is limited laterally by the occipital condyles and inferiorly by the C1 anterior arch and the odontoid process, which may need partial resection. OBJECTIVE We investigated the surgical anatomy and technical nuances for endonasally increasing the surgical corridor at the FM region both laterally and inferiorly. Unique to our report, we quantified the amount of required medial condyle resection to obtain exposure of the lateral aspects of the FM. METHODS Five fresh human head silicone-injected specimens underwent endonasal inferior transclival, transcondylar approaches. The lateral limit of medial condyle resection was defined using a vertical line extending inferiorly from foramen lacerum and its intersection with the occipital condyle. The condylectomy was limited posteriorly by the cortical bone surrounding the hypoglossal canal. The volume of the resected condyle (cubic centimeters) for 10 sides was measured using the pre- and postdissection computed tomography-volumetric analysis. RESULTS The mean percentage condylar volume resected during a unilateral medial condylectomy was 18% (9.7%-28.3%). The surgical corridor was extended inferiorly in all specimens without violating the transverse ligament by drilling the superior aspects of C1 anterior arch and the exposed odontoid tip. These operative nuances were successfully applied in the operating room. CONCLUSION Anatomical landmarks can reliably guide an endonasal anteromedial condyle resection. Minimal condyle resection is required to widen lateral access at the FM, which minimizes the risk of craniocervical instability.

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