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World Neurosurgery Oct 2023Lesions of the foramen magnum (FM) and craniocervical junction area are traditionally managed surgically through anterior, anterolateral, and posterolateral skull-base...
Approaching Intradural Lesions of the Anterior Foramen Magnum and Craniocervical Junction: Anatomical Comparison of the Open Posterolateral and Anterior Extended Endonasal Endoscopic Approaches.
BACKGROUND
Lesions of the foramen magnum (FM) and craniocervical junction area are traditionally managed surgically through anterior, anterolateral, and posterolateral skull-base approaches. This anatomical study aimed to compare the usefulness of a modified extended endoscopic approach, the so-called far-medial endonasal approach (FMEA), versus the traditional posterolateral far-lateral approach (FLA).
METHODS
Ten fixed silicon-injected heads specimens were used in the Skull Base ENT-Neurosurgery Laboratory of the University Hospital of Strasbourg, France. A total of 20 FLAs and 10 FMEAs were realized. A high-resolution computed tomography scan was performed for quantitative analysis of the different approaches. The analysis aimed to estimate the extent of surgical exposure and freedom of movement (maneuverability) through the operating channel using a polygonal surface model to obtain a morphometric estimation of the area of interest (surface and volume) on postdissection computed tomography scans using Slicer 3D software.
RESULTS
FMEA allows for a more direct route to the anterior FM, with wider brainstem exposure compared with the FLA and an excellent visualization of all anterior midline structures. The limitations of the FMEA include the deep and narrow surgical corridor and difficulty in reaching lesions located laterally over the jugular foramen and hypoglossal canal.
CONCLUSIONS
The FMEA and FLA are both effective surgical routes to reach FM and craniocervical junction lesions. Modern skull base surgeons should have a good command of both because they appear complementary. This anatomical study provides the tools for comprehensive preoperative evaluations and selection of the most appropriate surgical approach.
PubMed: 37482086
DOI: 10.1016/j.wneu.2023.07.080 -
The Neurohospitalist Jul 2023Jugular foramen syndrome (JFS) is a lower cranial neuropathy syndrome characterized by dysphonia and dysphagia. The syndrome is caused by dysfunction of the...
Jugular foramen syndrome (JFS) is a lower cranial neuropathy syndrome characterized by dysphonia and dysphagia. The syndrome is caused by dysfunction of the glossopharyngeal, vagus, and spinal accessory nerves at the level of the pars nervosa and pars vascularis within the jugular foramen. There are numerous etiologies for JFS, including malignancy, trauma, vascular, and infection. Here, we present the case of a healthy adult man who developed JFS secondary to an atypical presentation of Varicella Zoster meningitis, and was promptly diagnosed and treated with rapid symptom resolution. We diagnosed the patient using specialized skull-based imaging which detailed the jugular foramen, as well as CSF analysis. This case highlights the clinical value of detailed structural evaluation, consideration for infection in the absence of systemic symptoms, and favorable outcomes following early identification and treatment.
PubMed: 37441204
DOI: 10.1177/19418744221116717 -
Surgical Neurology International 2023The third ventricle colloid cyst (CC) is a benign growth usually located in the third ventricle and can cause various neurological symptoms, including sudden death....
BACKGROUND
The third ventricle colloid cyst (CC) is a benign growth usually located in the third ventricle and can cause various neurological symptoms, including sudden death. Modern surgical interventions may still result in a wide range of complications and cerebral venous thrombosis (CVT) is among them.
CASE DESCRIPTION
A 38-year-old female with an existing diagnosis of diabetes mellitus (DM) and hypothyroidism and a 6-month history of headaches, blurred vision, and vomiting presented to our clinic 3 days after the headaches became excessively severe. Neurological examination on admission revealed bilateral papilledema without any associated focal neurological deficits. Brain computed tomography and magnetic resonance imaging confirmed the presence of a third ventricle CC and associated non-communicating hydrocephalus involving the lateral ventricles. As a result, the patient underwent emergency bilateral external ventricular drainage (EVD) insertion followed by a third ventricular CC excision under neuronavigation through a right frontal craniotomy. Twelve days postoperatively, the patient developed further headaches followed by a generalized tonic-clonic seizure that led to no postictal neurological deficits. Nonetheless, computed tomography venography of the brain revealed extensive thrombosis of the superior sagittal sinus, inferior sagittal sinus, right sigmoid sinus, and right internal jugular vein. A newly diagnosed CVT was treated with intravenous heparin. The patient was discharged with warfarin, which was discontinued after 12 months. Ten years after her illness, she remained stable and free from any neurological deficits but still suffered from chronic mild headaches.
CONCLUSION
A preoperative venous study should be performed in all cases to gain a better understanding of the venous anatomy. We advocate meticulous microsurgical techniques to protect the venous system surrounding the foramen of Monro and reduce the amount of retraction during surgery.
PubMed: 37404486
DOI: 10.25259/SNI_348_2023 -
Operative Neurosurgery (Hagerstown, Md.) Oct 2023The extreme lateral approach is useful for both extradural and intradural anterior and anterolateral lesions at the lower clivus down to the level of C2.
INDICATIONS CORRIDOR AND LIMITS OF EXPOSURE
The extreme lateral approach is useful for both extradural and intradural anterior and anterolateral lesions at the lower clivus down to the level of C2.
ANATOMIC ESSENTIALS NEED FOR PREOPERATIVE PLANNING AND ASSESSMENT
The patient is evaluated with MRI, computed tomography (CT), and an angiogram. Special attention is given to vascular (vertebral artery course, dominance, tumor feeders) and bony (occipital condyle, jugular tubercle, foramen magnum and extent of bony involvement) anatomy.
ESSENTIALS STEPS OF THE PROCEDURE
The patient is positioned lateral with the head flexed and tilted down without axial rotation. A hockey-stick incision is performed, and the myocutaneous flap is raised. A retrocondylar craniectomy is performed. The extradural vertebral artery is exposed for proximal control. A C1 hemilaminectomy is performed. Cephalad/caudal exposure and drilling of the occipital condyle are determined per case. The dura is opened, and the vertebral artery is released at the dural entry point to facilitate the tumor removal. The tumor is debulked and delivered inferoventrally away from the neuroaxis and cranial nerves. After removing the tumor, the dura is closed using an allograft.The patients consented to the procedure and to the publication of their images.
PITFALLS/AVOIDANCE OF COMPLICATIONS
• Cranial nerve deficits• Craniocervical instability• Postoperative hydrocephalus• Postoperative pseudomeningocele.
VARIANTS AND INDICATIONS FOR THEIR USE
A transmastoid extension of the craniectomy allows access further rostrally in the clivus. For C1-2 chordomas, the approach is extended inferiorly, and the vertebral artery is mobilized out of the C1-2 transverse foramina. For tumors involving the joints, an occipitocervical stabilization is required.Images in video reused with permission as follows: image at 00:16 from Revuelta Barbero et al, Endoscopic endonasal transclival-medial condylectomy approach for resection of a foramen magnum meningioma: 2-dimensional operative video, Oper Neurosurg , 16(2), 2018, by permission from the Congress of Neurological Surgery; images at 00:30, and top image at 00:52 reused from Wen et al, Microsurgical anatomy of the transcondylar, supracondylar, and paracondylar extensions of the far-lateral approach, J Neurosurg , 87(4), 1997, with permission from JNSPG; bottom images at 00:52 from Muthukumar et al, A morphometric analysis of the foramen magnum region as it relates to the transcondylar approach, Acta Neurochir , 147(8), 2005, by permission from Springer Nature.
Topics: Humans; Occipital Bone; Foramen Magnum; Neurosurgical Procedures; Meningioma; Meningeal Neoplasms
PubMed: 37387583
DOI: 10.1227/ons.0000000000000739 -
The Neuroradiology Journal Dec 2023Intra-osseous vessels are normal anatomic structures in the calvarium and skull base. On imaging, these structures-particularly venous lakes-can mimic pathologic...
BACKGROUND
Intra-osseous vessels are normal anatomic structures in the calvarium and skull base. On imaging, these structures-particularly venous lakes-can mimic pathologic abnormalities. This study sought to assess the prevalence of veins and lakes in the skull base on MRI.
MATERIALS AND METHODS
A retrospective review was completed of consecutive patients that underwent contrast-enhanced MRI imaging of the internal auditory canals. The clivus, jugular tubercles, and basio-occiput were assessed for the presence of both intra-osseous veins (serpentine and/or branching vessels) and venous lakes (well-circumscribed round or oval enhancing structures). Vessels in the adjacent synchondroses major foramina were excluded. Three board-certified neuroradiologists performed independent blinded reviews, with discrepancies agreed upon by consensus.
RESULTS
96 patients were included in this cohort (58.3% female). Mean age was 58.4 years (range = 19-85). At least one intra-osseous vessel was identified in 71 (74.0%) patients. 67 (70.0%) had at least one skull base vein, and 14 (14.6%) had at least one venous lake. Both vessel subtypes were observed in 8.3% of patients. Vessels were more commonly observed in women, though this did not reach statistical threshold ( = 0.56). Age was not associated with the presence of vessels (0.59) or vessel location ( values ranged from 0.44-0.84).
CONCLUSIONS
Intra-osseous skull base veins and venous lakes are relatively common findings on MRI. Both vascular structures should be considered normal anatomy, and care should be taken to not confuse these for pathologic entities.
Topics: Humans; Female; Young Adult; Adult; Middle Aged; Aged; Aged, 80 and over; Male; Prevalence; Veins; Skull Base; Skull; Magnetic Resonance Imaging; Cranial Fossa, Posterior
PubMed: 37382936
DOI: 10.1177/19714009231187350 -
Operative Neurosurgery (Hagerstown, Md.) Nov 2023The endoscopic endonasal transpterygoid approach (EETPA) provides direct access to the petrous apex, lateral clivus, inferior cavernous sinus compartment, jugular...
INDICATIONS CORRIDOR AND LIMITS OF EXPOSURE
The endoscopic endonasal transpterygoid approach (EETPA) provides direct access to the petrous apex, lateral clivus, inferior cavernous sinus compartment, jugular foramen, and infratemporal fossa. 1,2 In the coronal plane, it provides exposure far beyond a traditional sphenoidotomy.
ANATOMIC ESSENTIALS NEED FOR PREOPERATIVE PLANNING AND ASSESSMENT
The pterygoid process of the sphenoid bone forms the junction between the body and greater sphenoid wing before bifurcating because it descends into medial and lateral plates. The key to this exposure lies in the region's bony foramina: the palatovaginal canal, vidian canal, and foramen rotundum. 3.
ESSENTIALS STEPS OF THE PROCEDURE
After performing a maxillary antrostomy, stepwise exposure of these foramina leads to the pterygopalatine fossa. The sphenopalatine artery is cauterized as it becomes the posterior septal artery at the sphenopalatine foramen, and the maxillary sinus' posterior wall is opened to expose the pterygopalatine fossa. After mobilizing and retracting the contents of the pterygopalatine fossa, the pterygoid process is removed, improving access in the coronal plane. 4.
PITFALLS/AVOIDANCE OF COMPLICATIONS
Vidian neurectomy causes decreased or absent lacrimation. Injury to the maxillary nerve or its branches results in facial, palatal, or odontogenic anesthesia or neuralgia. In addition, the EEPTA precludes the ability to raise an ipsilateral nasal septal flap, making it crucial to plan reconstruction preoperatively. 4,5.
VARIANTS AND INDICATIONS FOR THEIR USE
There are 5 variants of the EEPTA: extended pterygopalatine fossa, lateral recess of the sphenoid sinus, petrous apex, infratemporal fossa and petrous carotid artery, and middle and posterior skull base. 5The patient consented to the procedure.Images in the video used with permission as follows: images at 0:33 and 1:15 reused from Bozkurt et al, 3 © Georg Thieme Verlag KG; image at 0:39 from Prosser et al, 5 © John Wiley and Sons; images at 0:54, 9:03, and 9:38 from Kasemsiri et al, 1 © John Wiley and Sons; images at 1:07 and 9:44 from Falcon et al, 2 © John Wiley and Sons; image at 1:15 from Sandu et al, 4 © Springer Nature.
Topics: Humans; Skull Base; Nose; Endoscopy; Sphenoid Bone; Petrous Bone
PubMed: 37350591
DOI: 10.1227/ons.0000000000000738 -
Operative Neurosurgery (Hagerstown, Md.) Dec 2023This approach is intended for tumors centered in the jugular foramen with extensions between intracranial and extracranial spaces, possible spread to the middle ear, and...
INDICATIONS CORRIDOR AND LIMITS OF EXPOSURE
This approach is intended for tumors centered in the jugular foramen with extensions between intracranial and extracranial spaces, possible spread to the middle ear, and variable bony destruction. 1,2.
ANATOMIC ESSENTIALS NEED FOR PREOPERATIVE PLANNING AND ASSESSMENT
Jugular foramen paragangliomas are complex lesions that usually invade and fill related venous structures. They present complex relationships with skull base neurovascular structures as internal carotid artery, lower cranial nerves (CNs), middle ear, and mastoid segment of facial nerve. In this way, it is essential to perform an adequate preoperative vascular study to evaluate sinus patency and the tumor blood supply, besides a computed tomography scan to depict bone erosion.
ESSENTIAL STEPS OF THE PROCEDURE
Mastoidectomy through an infralabyrinthine route up to open the lateral border of jugular foramen, allowing exposure from the sigmoid sinus to internal jugular vein. Skeletonization of facial canal without exposure of facial nerve is performed and opening of facial recess to give access to the middle ear in way of a fallopian bridge technique. 2-10.
PITFALLS/AVOIDANCE OF COMPLICATIONS
If there is preoperative preservation of lower CN function, it is important to not remove the anteromedial wall of the internal jugular vein and jugular bulb. In addition, facial nerve should be exposed just in case of preoperative facial palsy to decompress or reconstruct the nerve.
VARIANTS AND INDICATIONS FOR THEIR USE
Variations are related mainly with temporal bone drilling depending on the extensions of the lesion, its source of blood supply, and preoperative preservation of CN function.Informed consent was obtained from the patient for the procedure and publication of his image.Anatomy images were used with permission from:• Ceccato GHW, Candido DNC, and Borba LAB. Infratemporal fossa approach to the jugular foramen. In: Borba LAB and de Oliveira JG. Microsurgical and Endoscopic Approaches to the Skull Base. Thieme Medical Publishers. 2021.• Ceccato GHW, Candido DNC, de Oliveira JG, and Borba LAB. Microsurgical Anatomy of the Jugular Foramen. In: Borba LAB and de Oliveira JG. Microsurgical and Endoscopic Approaches to the Skull Base. Thieme Medical Publishers. 2021.
Topics: Humans; Jugular Foramina; Skull Base; Glomus Jugulare Tumor; Temporal Bone; Cranial Nerves
PubMed: 37350587
DOI: 10.1227/ons.0000000000000775 -
Operative Neurosurgery (Hagerstown, Md.) Oct 2023
Topics: Humans; Jugular Foramina; Neurilemmoma; Craniotomy; Endoscopy; Endoscopes
PubMed: 37345947
DOI: 10.1227/ons.0000000000000800