Quantitative description of the far-lateral transcondylar transtubercular approach to the foramen magnum and clivus

2000 ◽  
Vol 92 (5) ◽  
pp. 824-831 ◽  
Author(s):  
Sergey Spektor ◽  
Gregory J. Anderson ◽  
Sean O. McMenomey ◽  
Michael A. Horgan ◽  
Jordi X. Kellogg ◽  
...  
Keyword(s):  
Pathological Condition ◽  
Quantitative Description ◽  
Foramen Magnum ◽  
Sigmoid Sinus ◽  
Occipital Condyle ◽  
Content Type ◽  
Suboccipital Craniectomy ◽  
Successive Step ◽  
Far Lateral ◽  
Fine Print

Object. The purpose of this study was to evaluate the far-lateral transcondylar transtubercular approach (complete FLA) based on quantitative measurements of the exposure of the foramen magnum and petroclival area obtained after each successive step of this approach.Methods. The complete FLA was reproduced in eight specially prepared cadaveric heads (a total of 15 sides). The approach was divided into six steps: 1) C-1 hemilaminectomy and suboccipital craniectomy with unroofing of the sigmoid sinus (basic FLA); 2) partial resection of the occipital condyle (up to the hypoglossal canal); 3) removal of the jugular tuberculum; 4) mastoidectomy (limited to the labyrinth and the fallopian canal) and retraction of the sigmoid sinus; 5) resection of the lateral mass of C-1 with mobilization of the vertebral artery; and 6) resection of the remaining portion of the occipital condyle. After each successive step, a standard set of measurements was obtained using a frameless stereotactic device. The measurements were used to estimate two parameters: the size of the exposed petroclival area and the size of a spatial cone directed toward the anterior rim of the foramen magnum, which depicts the amount of surgical freedom available for manipulation of instruments.The initial basic FLA provided exposure of only 21 ± 6% of the petroclival area that was exposed with the full, six-step maximally aggressive (complete) FLA. Likewise, only 18 ± 9% of the final surgical freedom was obtained after the basic FLA was performed. Each subsequent step of the approach increased both petroclival exposure and surgical freedom. The most dramatic increase in petroclival exposure was noted after removal of the jugular tuberculum (71 ± 12% of final exposure), whereas the least improvement in exposure occurred after the final step, which consisted of total condyle resection.Conclusions. The complete FLA provides wide and sufficient exposure of the foramen magnum and lower to middle clivus. The complete FLA consists of several steps, each of which contributes to increasing petroclival exposure and surgical freedom. However, the FLA may be limited to the less aggressive steps, while still achieving significant exposure and surgical freedom. The choice of complete or basic FLA thus depends on the underlying pathological condition and the degree of exposure required for effective surgical treatment.

Far-lateral approach to intradural lesions of the foramen magnum without resection of the occipital condyle

2002 ◽  
Vol 96 (2) ◽  
pp. 302-309 ◽  
Author(s):  
Anil Nanda ◽  
David A. Vincent ◽  
Prasad S. S. V. Vannemreddy ◽  
Mustafa K. Baskaya ◽  
Amitabha Chanda
Keyword(s):  
Craniocervical Junction ◽  
Foramen Magnum ◽  
Lateral Approach ◽  
Additional Patient ◽  
Occipital Condyle ◽  
Rheumatoid Disease ◽  
Content Type ◽  
Far Lateral Approach ◽  
Far Lateral ◽  
Fine Print

Object. The goal of this study was to determine whether drilling out the occipital condyle facilitates surgery via the far-lateral approach by comparing data from 10 clinical cases with that from studies of eight cadaver heads. Methods. During the last 6 years at Louisiana State University Health Sciences Center—Shreveport, 10 patients underwent surgery via the far-lateral approach to the foramen magnum. Six of these patients harbored anterior foramen magnum meningiomas, one patient a dermoid cyst, two patients vertebral artery (VA) aneurysms, and an additional patient suffered from rheumatoid disease of the craniocervical junction. The surgical approach consisted of retromastoid craniectomy and C-1 laminectomy. The seven tumors and the pannus of rheumatoid disease were completely excised, and the two aneurysms were clipped without drilling the occipital condyle. In one patient a chronic subdural hematoma was found 3 months after surgery, but no patient displayed any complication associated with surgery. It is significant that in no patient was a cerebrospinal fluid leak present. All patients experienced improved neurological function postoperatively. To compare surgical visibility, eight cadaveric specimens (16 sides) were studied, including delineation of the VA and its segments around the craniocervical junction. Increase in visibility as a function of fractional removal of the occipital condyle was quantified by measuring the degrees of visibility gained by removing one third and one half of the occipital condyle. Removal of one third of the occipital condyle produced a mean increase of 15.9° visibility, and removal of one half produced a mean increase of 19.9°. Conclusions. On the basis of their findings the authors conclude that removal of the occipital condyle is not necessary for the safe and complete resection of anterior intradural foramen magnum tumors.

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.

scholarly journals Far Lateral Craniotomy for Resection of Foramen Magnum Meningioma

2019 ◽  
Vol 80 (S 04) ◽  
pp. S355-S357
Author(s):  
Robert T. Wicks ◽  
Xiaochun Zhao ◽  
Celene B. Mulholland ◽  
Peter Nakaji
Keyword(s):  
Cranial Nerves ◽  
Craniocervical Junction ◽  
Foramen Magnum ◽  
Occipital Condyle ◽  
Formidable Challenge ◽  
Close Proximity ◽  
Vertebrobasilar Circulation ◽  
Far Lateral ◽  
Lower Cranial Nerves ◽  
Gain Access

Abstract Objective Foramen magnum meningiomas present a formidable challenge to resection due to frequent involvement of the lower cranial nerves and vertebrobasilar circulation. The video shows the use of a far lateral craniotomy to resect a foramen magnum meningioma. Design, Setting, and Participant A 49-year-old woman presented with neck pain and was found to have a large foramen magnum meningioma (Fig. 1A, B). Drilling of the posterior occipital condyle was required to gain access to the lateral aspect of the brain stem. The amount of occipital condyle resection varies by patient and pathology. Outcome/Result Maximal total resection of the tumor was achieved (Fig. 1B, C), and the patient was discharged on postoperative day 4 with no neurologic deficits. The technique for tumor microdissection (Fig. 2) is shown in the video. Conclusion Given the close proximity of foramen magnum meningiomas to vital structures at the craniocervical junction, surgical resection with careful microdissection and preservation of the overlying dura to prevent postoperative pseudomeningocele is necessary to successfully manage this pathology in those patients who are surgical candidates.The link to the video can be found at: https://youtu.be/Mds9N1x2zE0.

Diagnosis and microsurgical approach to far-lateral disc herniation in the lumbar spine

1990 ◽  
Vol 72 (3) ◽  
pp. 378-382 ◽  
Author(s):  
Joseph C. Maroon ◽  
Thomas A. Kopitnik ◽  
Larry A. Schulhof ◽  
Adnan Abla ◽  
James E. Wilberger
Keyword(s):  
Facet Joint ◽  
Lumbar Disc ◽  
Spinal Nerve ◽  
Magnetic Resonance Images ◽  
Content Type ◽  
Enhanced Ct ◽  
Disc Herniations ◽  
Microsurgical Approach ◽  
Far Lateral ◽  
Fine Print

✓ Lumbar-disc herniations that occur beneath or far lateral to the intervertebral facet joint are increasingly recognized as a cause of spinal nerve root compression syndromes at the upper lumbar levels. Failure to diagnose and precisely localize these herniations can lead to unsuccessful surgical exploration or exploration of the incorrect interspace. If these herniations are diagnosed, they often cannot be adequately exposed through the typical midline hemilaminectomy approach. Many authors have advocated a partial or complete unilateral facetectomy to expose these herniations, which can lead to vertebral instability or contribute to continued postoperative back pain. The authors present a series of 25 patients who were diagnosed as having far lateral lumbar disc herniations and underwent paramedian microsurgical lumbar-disc excision. Twelve of these were at the L4–5 level, six at the L5–S1 level, and seven at the L3–4 level. In these cases, myelography is uniformly normal and high-quality magnetic resonance images may not be helpful. High-resolution computerized tomography (CT) appears to be the best study, but even this may be negative unless enhanced by performing CT-discography. Discography with enhanced CT is ideally suited to precisely diagnose and localize these far-lateral herniations. The paramedian muscle splitting microsurgical approach was found to be the most direct and favorable anatomical route to herniations lateral to the neural foramen. With this approach, there is no facet destruction and postoperative pain is minimal. Patients were typically discharged on the 3rd or 4th postoperative day. The clinical and radiographic characteristics of far-lateral lumbar-disc herniations are reviewed and the paramedian microsurgical approach is discussed.

scholarly journals Intracranial solitary chondroma

1984 ◽  
Vol 61 (2) ◽  
pp. 399-401 ◽  
Author(s):  
Tunçalp Özgen ◽  
M. Necmettin Pamir ◽  
Nejat Akalan ◽  
Vural Bertan ◽  
Behsan Önol
Keyword(s):  
Computerized Tomography ◽  
Pathological Condition ◽  
Diagnostic Value ◽  
Falx Cerebri ◽  
Content Type ◽  
Intracranial Chondroma ◽  
Fine Print

✓ A patient is described who had a solitary left frontal intracranial chondroma originating from the falx cerebri. The tumor was totally removed. The diagnostic value of computerized tomography and the surgical findings in this rare pathological condition are discussed.

Tonsillar herniation: the rule rather than the exception after lumboperitoneal shunting in the pediatric population

1993 ◽  
Vol 78 (4) ◽  
pp. 568-573 ◽  
Author(s):  
Paul D. Chumas ◽  
Derek C. Armstrong ◽  
James M. Drake ◽  
Abhaya V. Kulkarni ◽  
Harold J. Hoffman ◽  
...  
Keyword(s):  
Morphological Changes ◽  
Pediatric Population ◽  
Pseudotumor Cerebri ◽  
Foramen Magnum ◽  
Tonsillar Herniation ◽  
Content Type ◽  
Asymptomatic Patients ◽  
The Mean ◽  
Sick Children ◽  
Fine Print

✓ Although the development of tonsillar herniation (acquired Chiari malformation) in association with lumboperitoneal (LP) shunting is well recognized, it has previously been considered rare. In order to ascertain the incidence of this complication after LP shunting, the authors undertook a retrospective study of all patients in whom this form of shunt had been inserted between 1974 and 1991 at The Hospital for Sick Children, Toronto. In the 143 patients, the mean age at insertion was 3.3 years and the indications for shunt placement were hydrocephalus (81%), pseudotumor cerebri (7%), cerebrospinal fluid fistula (6%), and posterior fossa pseudomeningocele (6%). The mean follow-up period was 5.7 years, during which time there was one shunt-related death due to unsuspected tonsillar herniation. Five other patients developed symptomatic tonsillar herniation treated by suboccipital decompression. Review of all computerized tomography (CT) scans not degraded by artifact showed evidence of excess soft tissue at the level of the foramen magnum in 38 (70%) of 54 patients so studied. In order to confirm that this CT finding represented hindbrain herniation, sagittal and axial magnetic resonance (MR) images were obtained for 17 asymptomatic patients and revealed tonsillar herniation (range 2 to 21 mm) in 12 (70.6%). In addition, some of these asymptomatic patients had evidence of uncal herniation and mesencephalic distortion. Similarities and distinctions are drawn between the morphological changes occurring after LP shunting and those seen in association with the Chiari I and II malformations. Although less than 5% of this study population required treatment for tonsillar herniation, the incidence of this complication was high in asymptomatic patients; MR imaging surveillance for patients with LP shunts is therefore recommended.

Elucidating the pathophysiology of syringomyelia

1999 ◽  
Vol 91 (4) ◽  
pp. 553-562 ◽  
Author(s):  
John D. Heiss ◽  
Nicholas Patronas ◽  
Hetty L. DeVroom ◽  
Thomas Shawker ◽  
Robert Ennis ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Subarachnoid Space ◽  
Foramen Magnum ◽  
Chiari I Malformation ◽  
Content Type ◽  
Cine Mr ◽  
Spinal Subarachnoid Space ◽  
Chiari I ◽  
Cerebellar Tonsils ◽  
Fine Print

Object. Syringomyelia causes progressive myelopathy. Most patients with syringomyelia have a Chiari I malformation of the cerebellar tonsils. Determination of the pathophysiological mechanisms underlying the progression of syringomyelia associated with the Chiari I malformation should improve strategies to halt progression of myelopathy.Methods. The authors prospectively studied 20 adult patients with both Chiari I malformation and symptomatic syringomyelia. Testing before surgery included the following: clinical examination; evaluation of anatomy by using T1-weighted magnetic resonance (MR) imaging; evaluation of the syrinx and cerebrospinal fluid (CSF) velocity and flow by using phase-contrast cine MR imaging; and evaluation of lumbar and cervical subarachnoid pressure at rest, during the Valsalva maneuver, during jugular compression, and following removal of CSF (CSF compliance measurement). During surgery, cardiac-gated ultrasonography and pressure measurements were obtained from the intracranial, cervical subarachnoid, and lumbar intrathecal spaces and syrinx. Six months after surgery, clinical examinations, MR imaging studies, and CSF pressure recordings were repeated. Clinical examinations and MR imaging studies were repeated annually. For comparison, 18 healthy volunteers underwent T1-weighted MR imaging, cine MR imaging, and cervical and lumbar subarachnoid pressure testing.Compared with healthy volunteers, before surgery, the patients had decreased anteroposterior diameters of the ventral and dorsal CSF spaces at the foramen magnum. In patients, CSF velocity at the foramen magnum was increased, but CSF flow was reduced. Transmission of intracranial pressure across the foramen magnum to the spinal subarachnoid space in response to jugular compression was partially obstructed. Spinal CSF compliance was reduced, whereas cervical subarachnoid pressure and pulse pressure were increased. Syrinx fluid flowed inferiorly during systole and superiorly during diastole on cine MR imaging. At surgery, the cerebellar tonsils abruptly descended during systole and ascended during diastole, and the upper pole of the syrinx contracted in a manner synchronous with tonsillar descent and with the peak systolic cervical subarachnoid pressure wave. Following surgery, the diameter of the CSF passages at the foramen magnum increased compared with preoperative values, and the maximum flow rate of CSF across the foramen magnum during systole increased. Transmission of pressure across the foramen magnum to the spinal subarachnoid space in response to jugular compression was normal and cervical subarachnoid mean pressure and pulse pressure decreased to normal. The maximum syrinx diameter decreased on MR imaging in all patients. Cine MR imaging documented reduced velocity and flow of the syrinx fluid. Clinical symptoms and signs improved or remained stable in all patients, and the tonsils resumed a normal shape.Conclusions. The progression of syringomyelia associated with Chiari I malformation is produced by the action of the cerebellar tonsils, which partially occlude the subarachnoid space at the foramen magnum and act as a piston on the partially enclosed spinal subarachnoid space. This creates enlarged cervical subarachnoid pressure waves that compress the spinal cord from without, not from within, and propagate syrinx fluid caudally with each heartbeat, which leads to syrinx progression. The disappearance of the abnormal shape and position of the tonsils after simple decompressive extraarachnoidal surgery suggests that the Chiari I malformation of the cerebellar tonsils is acquired, not congenital. Surgery limited to suboccipital craniectomy, C-1 laminectomy, and duraplasty eliminates this mechanism and eliminates syringomyelia and its progression without the risk of more invasive procedures.

Stability of the craniovertebral junction after unilateral occipital condyle resection: a biomechanical study

1999 ◽  
Vol 90 (1) ◽  
pp. 91-98 ◽  
Author(s):  
A. Giancarlo Vishteh ◽  
Neil R. Crawford ◽  
M. Stephen Melton ◽  
Robert F. Spetzler ◽  
Volker K. H. Sonntag ◽  
...  
Keyword(s):  
Axial Rotation ◽  
Craniovertebral Junction ◽  
Biomechanical Study ◽  
Occipital Condyle ◽  
Upper Cervical Spine ◽  
Lateral Bending ◽  
Content Type ◽  
Axial Translation ◽  
Flexion Extension ◽  
Fine Print

Object. The authors sought to determine the biomechanics of the occipitoatlantal (occiput [Oc]—C1) and atlantoaxial (C1–2) motion segments after unilateral gradient condylectomy. Methods. Six human cadaveric specimens (skull with attached upper cervical spine) underwent nondestructive biomechanical testing (physiological loads) during flexion—extension, lateral bending, and axial rotation. Axial translation from tension to compression was also studied across Oc—C2. Each specimen served as its own control and underwent baseline testing in the intact state. The specimens were then tested after progressive unilateral condylectomy (25% resection until completion), which was performed using frameless stereotactic guidance. At Oc—C1 for all motions that were tested, mobility increased significantly compared to baseline after a 50% condylectomy. Flexion—extension, lateral bending, and axial rotation increased 15.3%, 40.8%, and 28.1%, respectively. At C1–2, hypermobility during flexion—extension occurred after a 25% condylectomy, during axial rotation after 75% condylectomy, and during lateral bending after a 100% condylectomy. Conclusions. Resection of 50% or more of the occipital condyle produces statistically significant hypermobility at Oc—C1. After a 75% resection, the biomechanics of the Oc—C1 and C1–2 motion segments change considerably. Performing fusion of the craniovertebral junction should therefore be considered if half or more of one occipital condyle is resected.

Endoscopic removal of cysticercal cysts within the fourth ventricle

1999 ◽  
Vol 91 (2) ◽  
pp. 340-345 ◽  
Author(s):  
Marvin Bergsneider
Keyword(s):  
Fourth Ventricle ◽  
Treatment Options ◽  
Primary Treatment ◽  
Surgical Removal ◽  
Endoscopic Removal ◽  
Content Type ◽  
Suboccipital Craniectomy ◽  
The Mean ◽  
Optimum Management ◽  
Fine Print

✓ There is no consensus as to the optimum management of patients who harbor cysticercal cysts within the fourth ventricle. Compared with the alternative treatment options of anthelmintic medication and/or cerebrospinal fluid shunt placement, the surgical removal of the cyst has the advantage of eliminating the inflammatory nidus and potentially obviating the need for a complication-prone shunt. Here, an endoscopic surgical approach is described and proposed as an alternative to the standard suboccipital craniectomy for removal of cysticercal cysts within the fourth ventricle.A retrospective analysis of five consecutive endoscopic cases was performed. Endoscopic removal of all cysts within the fourth ventricle was successful in each case. The mean length of operative time was short and blood loss was insignificant. The endoscopic procedure was safe and associated with minimal postoperative discomfort in most patients.In properly selected patients, the endoscopic removal of cysticercal cysts located within the fourth ventricle should be considered as the primary treatment for this condition.

Cervical myelopathy due to ossification of the posterior longitudinal longitudinal ligament

1972 ◽  
Vol 37 (6) ◽  
pp. 653-660 ◽  
Author(s):  
Chikao Nagashima
Keyword(s):  
Cervical Myelopathy ◽  
Posterior Margin ◽  
Posterior Longitudinal Ligament ◽  
Foramen Magnum ◽  
Primary Lesion ◽  
Foramen Magnum Decompression ◽  
Decompressive Laminectomy ◽  
Content Type ◽  
Longitudinal Strip ◽  
Fine Print

✓ Ten patients who had cervical myelopathy due to ossification of the posterior longitudinal ligament of the cervical spine are described. This disease is characterized by an abnormal longitudinal strip of ossified ligamentous tissue along the posterior margin of vertebrae from C-3 to C-6; the primary lesion appears to be a degeneration of the intervertebral disc. This distinct clinical, radiological, and pathological entity should be included in the differential diagnosis of cervical myelopathy. All 10 patients were treated by extensive decompressive laminectomy and multiple bilateral facetectomies, with or without foramen magnum decompression. The results were favorable, and postoperative myelography demonstrated dorsal migration of the entire dural contents.

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