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STUDY DESIGN: We reviewed the available literature systematically without meta-analysis following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. OBJECTIVE: To evaluate contemporary literature on use of spinal diffusion tensor imaging(sDTI) in spinal pathology. BACKGROUND: sDTI reveals the location and functional state of critical long tracts and is a potentially useful adjunct in disease management. METHODS: Studies were included if they presented or discussed data from investigative or therapeutic procedures involving sDTI on human subjects in the setting of surgically amenable spinal pathology. Studies were excluded if they were (1) restricted to computational models investigating parameters using data not obtained clinically, (2) about cranial DTI methods, (3) about spinal pathology data not related to surgical management, (4) discussions or overviews of methods/techniques with minimal inclusion of objective experimental or clinical data. RESULTS: Degenerative pathologies of interest were restricted to either cervical myelopathy (22/29,75.9%) or lumbar spondylosis 7/29,24.1%). Mass-occupying lesions included intradural pathology and discussed preoperative (7/9,77.8%) and intraoperative imaging(2/9,22.2%) as an adjunct to surgery 22.2%. Traumatic pathology focused on spinal cord injury prognosis and severity grading. CONCLUSIONS: sDTI seems useful in surgical decision making and outcome measurements and in establishing clinical prognoses over a wide range of surgical pathologies. Further research is warranted with longer follow-up and larger population sizes in a prospective and controlled protocol.
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Background: Salvage revisions of atlantoaxial (AA) joint complex posterior segmental instrumented fusion constructs require careful individualized planning to prevent occipital extension. In this case report, we describe the use of bilateral intrafacet spacer placement as a mobility-sparing bailout option for the revision surgery. Case Report: A 64-year-old male with a history of diffuse idiopathic skeletal hyperostosis, extremely limited baseline cervical mobility, and prior AA posterior segmental instrumented fusion presented with increasing pain at his 6-month follow-up. Imaging showed fusion and hardware failures and dynamic instability. To prevent occipitocervical fixation, AA intra-articular fusion via a DTRAX spinal system (Providence Medical Technology, Inc) was used as an adjunct to a navigated C1 lateral mass and C2 pars screw posterior segmental instrumented fusion construct. The patient had an uneventful postoperative course and was discharged with resolution of symptoms. Three-month postoperative follow-up confirmed persistent resolution of symptoms and absence of complaints, along with successful arthrodesis on imaging. Conclusion: AA posterior segmental instrumented fusion revision is technically challenging, particularly when partial preservation of craniovertebral junction mobility is required. Bilateral intra-articular cages may be used as an adjunct to hardware revision in construct salvage when sturdy arthrodesis is desired without occipital extension and may represent a major potential strength of intra-articular cages.
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Background: The rapid evolution of neuroendovascular intervention has resulted in the inclusion of endovascular techniques as a core competency in neurosurgical residency training. Methods: We conducted a literature review of studies involving the training of neurosurgical residents in cerebrovascular and endovascular neurosurgery. We reviewed the evolution of cerebrovascular neurosurgery and the effects of these changes on residency, and we propose interventions to supplement contemporary training. Results: A total of 48 studies were included for full review. Studies evaluated trainee education and competency (29.2%, 14/48), neuroendovascular training models (20.8%, 10/48), and open cerebrovascular training models (52.1%, 25/48), with some overlap. We used a qualitative analysis of reviewed reports to generate a series of suggested training supplements to optimize cerebrovascular education. Conclusion: Cerebrovascular neurosurgery is at a crossroads where trainees must develop disparate skill sets with inverse trends in volume. Continued longitudinal exposure to both endovascular and open cerebrovascular surgical fields should be mandated in general resident education, and blended learning tactics using adjunct simulation systems and models should be incorporated with didactics to both optimize learning and alleviate restraints placed by decreased volume and autonomy.
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INTRODUCTION: To investigate the locations of the anterior, middle, and posterior ethmoidal foramina and their relationships to the frontoethmoidal suture. METHODS: One hundred twenty sides from sixty adult human skulls were used. Specimens with significant damage to the medial orbit wall were excluded. The number of ethmoidal foramina (anterior, middle, and posterior) on the medial orbital wall and the relationship of each foramen to the frontoethmoidal suture were recorded and classified as follows: Type I: superior to the frontoethmoidal suture; Type II: on the frontoethmoidal suture; Type III: inferior to the frontoethmoidal suture. RESULTS: Of the ninety-four sides, fourteen (14.9%) had one foramen, sixty-two (66.0%) had two , and eighteen (19.1%) had three. In total, 192 ethmoidal foramina were observed. Among the fourteen sides with one foramen, eight foramina were anterior and six were posterior. Among the 192 ethmoidal foramina, 162 were eligible for fur ther classification (74 anterior, 14 middle, and 74 posterior). Types I, II, and III ethmoidal foramina were found in 38.3% (62/162), 61.7% (100/162), and 0% (0/162), respectively. CONCLUSIONS: Our current study found a higher incidence of type I than previously reported. It is important to be aware of the significant incidence of foramen variations when the medial orbit wall is manipulated during surgery. Unless caution is observed, an inadvertent surgical injury can occur and lead to life-threatening complications. Therefore, a good understanding of orbital anatomy and its potential variations is critical for improving patient out comes.
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Hueso Etmoides , Hueso Frontal , Humanos , Hueso Etmoides/anatomía & histología , Hueso Etmoides/cirugía , Hueso Frontal/anatomía & histología , Hueso Frontal/cirugía , Adulto , Cadáver , Órbita/anatomía & histología , Órbita/cirugía , Suturas Craneales/anatomía & histología , Masculino , Senos Etmoidales/cirugía , Senos Etmoidales/anatomía & histología , FemeninoRESUMEN
Background: Endovascular mechanical thrombectomy (EVT) for large vessel occlusions has had a dramatic impact on the management of acute ischemic stroke. Extended use of EVT beyond American Heart Association guidelines has been successful in carefully selected cases. Case Report: A 71-year-old male presented to our comprehensive stroke center upon awakening with mild left hemiparesis. He was found to have a chronic occlusion of the right supraclinoid segment of the internal carotid artery. Angiography demonstrated large vessel occlusion of the contralateral A1-A2 junction that was successfully recanalized. Imaging at 24 hours displayed no evidence of infarct, the patient rapidly improved during hospitalization, and he was discharged on postoperative day 7 with a National Institutes of Health Stroke Scale score of zero. Conclusion: We describe successful EVT of a patient presenting with false-localizing symptoms consistent with a right hemispheric acute ischemic stroke secondary to left A1-A2 junction large vessel occlusion. This case demonstrates the importance of a high index of suspicion when evaluating atypical stroke presentations and the effectiveness of EVT in the treatment of distal small-caliber vessels.
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High-flow grade-III dural arteriovenous fistulae(dAVF) represent rare abnormal vascular connections with a high risk of rupture. Management involves obliteration of both the fistulous connection as well as the draining venous network with preservation of normal vasculature. We describe and multiple neonatal dAVFs inducing cardiomyopathy via high-flow grade III shunting in the anterior circulation successfully treated via transvenous and transarterial embolization.
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Malformaciones Vasculares del Sistema Nervioso Central , Embolización Terapéutica , Recién Nacido , Humanos , Angiografía Cerebral , Malformaciones Vasculares del Sistema Nervioso Central/terapia , Malformaciones Vasculares del Sistema Nervioso Central/cirugía , Procedimientos Quirúrgicos Vasculares , Procedimientos NeuroquirúrgicosRESUMEN
INTRODUCTION: The atypical anatomy of the C2 vertebra has led to terminological discrepancies within reports and studies in the literature regarding the location of its pedicle, pars interarticularis, and isthmus. These discrepancies not only limit the power of morphometric analyses, but they also confuse technical reports regarding operations involving C2, and thus confuse our ability to properly communicate this anatomy. Herein, we examine the variations in nomenclature regarding the pedicle, pars interarticularis, and isthmus of C2, and via an anatomical study, propose new terminology. METHODS: The articular surface and underlying superior and inferior articular processes and adjacent transverse processes were removed from 15 C2 vertebrae (30 sides). Specifically, the areas regarded as the pedicle, pars interarticularis, and isthmus were evaluated. Morphometrics were performed. RESULTS: Our results indicate that, anatomically, C2 has no "isthmus" and that a pars interarticularis for C2, when present, is very short. Deconstruction of the attached parts allowed for visualization of a bony arch extending from the anterior most aspect of the lamina to the body of C2. The arch is composed almost entirely of trabecular bone and without its attached parts, e.g., transverse process, really has no cortical bone laterally. CONCLUSIONS: We propose a more accurate terminology, the pedicle, for pars/pedicle screw placement of C2. Such a term more accurately describes this unique structure of the C2 vertebra and would alleviate terminological confusion in the future literature on this topic.
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Vértebra Cervical Axis , Tornillos Pediculares , Fusión Vertebral , Humanos , Vértebra Cervical Axis/cirugía , Fusión Vertebral/métodos , Hueso Cortical , Vértebras CervicalesRESUMEN
BACKGROUND: Ventral lesions of the subaxial cervical spine are challenging because approaches must circumvent endodermal and neurovascular structures. OBJECTIVE: To use cadaveric study to describe 4 posterolateral approaches to the ventral subaxial cervical spine with various facilitating techniques and osteotomies. METHODS: Three cadaveric specimens of the cervical spine were sequentially subjected to multilevel laminectomy (Type 1), transfacet (Type 2), transpedicular (Type 3), and extreme lateral transforaminal (Type 4) approaches. Approach working angles and proportion of visualized zones were compared, the former calculated using trigonometric methods. RESULTS: There was a significant stepwise increase in working angle in the ventral space, associated with increasing osteotomy type, from an average of 3.7° in single-level type 1 to 19.47° in the type 4 osteotomy. Regarding anatomic zones, proportional partial and total visualization achieved with Type 2 to 4 approaches were significantly greater than with Type 1. Complex osteotomies allowed superior access to be obtained to contributing and adjacent vessels of the ventral spinal axis. CONCLUSION: Ventral subaxial cervical lesions are difficult to access. We report increased working angles using quantified cadaveric data in increasingly complex posterior and posterolateral approaches graded as type 1 through 4. We advocate continued translational research in such approaches to lesions often considered to lie in surgically inaccessible locations.
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Laminectomía , Osteotomía , Humanos , Laminectomía/métodos , Cuello/cirugía , Vértebras Cervicales/cirugía , CadáverRESUMEN
Objective Trigeminal neuralgia (TN) is a debilitating syndrome characterized by paroxysmal facial pain in one or more divisions of the trigeminal nerve. The etiology and treatment paradigms are still controversial. The endoscopically-assisted procedure has not yet been described in percutaneous procedures for TN. The aim of this study was to assess the utility and feasibility of endoscopic-assisted percutaneous approaches for trigeminal rhizotomy in TN. Methods This study comprised eight cadaveric sides heads that underwent an endoscopically assisted percutaneous approach using Hakanson's anterior puncture method for targeting the foramen ovale. Results V3 exiting the foramen ovale was easily visualized with the endoscope on all sides. While approaching the foramen ovale, distal branches of V3 such as the lingual and inferior alveolar nerves were first identified as they traveled between the medial and lateral pterygoid muscles. These branches were then traced proximally to the V3 trunk deep to the lateral pterygoid. Large arteries and veins were easily visualized and avoided in the trajectory to the foramen ovale. No gross injury to any neurovascular structure along the course of the needle insertion was identified. Conclusion We found that endoscopic-assisted percutaneous approach to the foramen ovale is feasible and allows for accurate canalization and anatomical identification of the precise location for rhizotomy under direct visualization. Such a procedure, after it is confirmed in patients, could offer a new technique for reducing unsuccessful canalization and could improve outcomes.
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BACKGROUND: Isolated spinal aneurysms (iSAs) are lesions of the spinal vasculature with no associated vascular malformation with difficult management paradigms limited by safe access. OBJECTIVE: To describe a case of an irregular fusiform ruptured distal subaxial cervical spine iSA with a complex angioarchitecture intimately associated with the ventral pial plexus (VPP), treated using open clip ligation and disconnection. METHODS: A 51-year-old woman presented with complete spinal cord injury with a C8 sensory level and ventral subarachnoid hemorrhage at the C6-T1 vertebral levels. After emergent anterior evacuation and fusion, angiography revealed a small iSA around the VPP. A total laminectomy spanning C5 to T3 was completed, and bilateral C7 pedicle resections were performed. A temporary clip was placed from the left for proximal control, and a permanent clip was placed across the dome of the distal vessel for disconnection. The dura was then closed, and a cervicothoracic fusion completed. RESULTS: Postoperative angiography confirmed iSA disconnection and obliteration with anterior spinal artery preservation. The patient had intermittent numbness in the right C8 dermatome. On postoperative day 1, she regained proprioception in the right foot and movement in the lower extremities on command. On postoperative day 3, she regained full sensation and voluntary movement in both lower extremities. CONCLUSION: iSA is a rare and morbid condition with nonstandardized guidelines regarding management. We promote the concept of using tailored osteotomies to establish safe corridors for the open treatment of difficult subaxial cervical ventral lesions not amenable to transarterial treatment. Multidisciplinary collaboration is promising, and further investigation is highly warranted.
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Aneurisma Roto , Hemorragia Subaracnoidea , Femenino , Humanos , Persona de Mediana Edad , Aneurisma Roto/diagnóstico por imagen , Aneurisma Roto/cirugía , Vértebras Cervicales/diagnóstico por imagen , Vértebras Cervicales/cirugía , Hemorragia Subaracnoidea/diagnóstico por imagen , Hemorragia Subaracnoidea/cirugía , Osteotomía , Instrumentos QuirúrgicosRESUMEN
Cat scratch disease (CSD), caused by Bartonella henselae, may atypically present with vertebral osteomyelitis. Antibiotic regimens are tailored to presentation, which is markedly variable and not well defined for any atypical disease. In cases of spinal instability, the use of antibiotics alone may not be sufficient. Atlantoaxial instability caused by osteomyelitis is a rare complication of CSD. In this report, we describe the rare case of vertebral osteomyelitis complicated by atlantoaxial instability, requiring both antibiotics and atlantoaxial fusion. We discuss our case, surgical technique, rationale, and outcome. In addition, we conducted a systematic review of the literature of vertebral osteomyelitis in pediatric secondary to B. henselae. A 2-year-old child presented with a 2-month history of irritability, fever, and rigid neck pain along with a recent history of feline exposure. Physical examination revealed cervical tenderness and decreased range of motion. Computed tomography (CT) showed osteolysis of the right C1 lateral mass and pars articularis; T1-weighted magnetic resonance imaging with contrast showed enhancement around the right C1 lateral mass. The titer for B. henselae was high. A diagnosis of cat scratch osteomyelitis with cervical instability was made, for which the patient underwent surgery with atlantoaxial fusion. Postoperative imaging demonstrated resolution of the contrast-enhanced lesion. At 6-year follow-up, the patient showed no signs of residual complications from surgical intervention with a solid fusion. Our review revealed 44 cases of pediatric CSD vertebral osteomyelitis. Conservative management with antibiotic employed in 86% while antibiotics with surgical intervention in 14% of the cases. Surgical intervention was most often in the form of incision for drainage and decompression without fusion. Average follow-up 10 months with 86% achieved complete resolution. Cervical instability caused by osteolysis is a rare complication of CSD. This can subsequently lead to vertebral instability, requiring definitive surgical intervention.
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Background: Loss of lumbar lordosis caused by single level degenerative spondylolisthesis can trigger significant sagittal plane imbalance and failure to correct lumbopelvic parameters during lumbar fusion can lead to poor outcome or worsening deformity. Anterior column release (ACR) through a pre-psoas approach allows the placement of a hyperlordotic cage (HLC) to improve lumbar lordosis, but it is unclear if the amount of cage lordosis affects radiological outcomes in real-life patient conditions. Methods: Three patients were treated with ACR and 30° expandable HLC for positive sagittal imbalance secondary to single-level spondylolisthesis. Patients reported baseline and post-operative Oswestry Disability Index (ODI) and Numeric Pain Score (NRS). Radiographic parameters of sagittal balance included lumbar lordosis (LL), sagittal vertical axis (SVA) and pelvic incidence-lumbar lordosis mismatch (PI-LL). Results: Surgical indications were sagittal plane imbalance caused by L4-L5 degenerative spondylolisthesis (n = 2) and L3-L4 spondylolisthesis secondary to adjacent segmental degeneration (n = 1). Average post-operative length of stay was 3 days (range 2-4) and estimated blood loss was 266 mL (range 200-300). NRS and ODI improved in all patients. All experienced improvements in LL (x¯preop = 33°, x¯postop = 56°), SVA (x¯preop = 180 mm, x¯postop = 61 mm) and PI-LL (x¯preop = 26°, x¯postop = 5°). Conclusion: ACR with expandable HLC can restore sagittal plane balance associated with single-level spondylolisthesis. Failure to perform ACR with HLC placement during pre-psoas interbody fusion may result in under correction of lordosis and poorer outcome for these patients.
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Lordosis , Fusión Vertebral , Espondilolistesis , Humanos , Lordosis/etiología , Lordosis/cirugía , Vértebras Lumbares/cirugía , Estudios Retrospectivos , Espondilolistesis/complicaciones , Espondilolistesis/cirugía , Resultado del TratamientoRESUMEN
BACKGROUND: Spontaneous resolution of syringomyelia has rarely been reported in the literature. Rarer still are cases wherein this process is associated with pregnancy and parturition. We review theories on syringomyelia development and spontaneous resolution to better understand the role pregnancy and parturition may play in both processes. METHODS: We present a 30-year-old female with MRI-confirmed spontaneous syrinx regression following caesarean delivery of a full-term pregnancy. We additionally review the literature to identify previously reported cases of spontaneous syrinx regression both independent of and associated with pregnancy. RESULTS: Including the present case, 39 cases describing spontaneous regression of syringomyelia have been reported in the literature, of which only four are associated with pregnancy and parturition. 75% of all reported cases were associated with type I Chiari malformation, though several disorders of the craniocervical junction and spinal canal were implicated. Complete syrinx regression was achieved in 33.3% of cases and 5% of cases described recurrence of syringomyelia following the spontaneous resolution. CONCLUSION: Syringomyelia likely develops due to disturbance of the physiologic flow of cerebrospinal fluid around the craniocervical junction and the obex. Several mechanisms including fissuring of the spinal cord parenchyma and reduction of subarachnoid scarring are likely involved in this process. In the setting of pregnancy, additional mechanisms surrounding the increased intraabdominal forces imparted by a growing fetus, Valsalva-like strain experienced during labor, and hemodynamic changes that occur to accommodate gestation are likely implicated. Nevertheless, patients should continue to be monitored periodically for syrinx recurrence.
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Malformación de Arnold-Chiari , Siringomielia , Embarazo , Femenino , Humanos , Adulto , Siringomielia/complicaciones , Siringomielia/diagnóstico por imagen , Malformación de Arnold-Chiari/complicaciones , Malformación de Arnold-Chiari/diagnóstico por imagen , Espacio Subaracnoideo , Imagen por Resonancia Magnética , PartoRESUMEN
INTRODUCTION: The mastoid emissary vein (MEV) describes a transosseous connection between the sigmoid dural venous sinus and the suboccipital venous plexus. In cases of outflow stenosis or malformation, the MEV may become dilated and a source of pulsatile tinnitus (PT) amenable to treatment. We describe a case of PT secondary to MEV treated successfully via endovascular coil embolization and conduct a systematic review of the literature. METHODS: We performed a systematic review without meta-analysis of studies involving management of dilated MEV on January 14, 2022, and describe a case of PT secondary to an enlarged MEV treated via coil embolization. RESULTS: A total of 13 studies were selected for full review. Reports identified MEV presenting as PT in 60% (12 of 20) of cases, intraoperative hemorrhage in mastoid surgery in 15% (3 of 20), a compressive scalp mass in 10% (2 of 20), and thrombophlebitis, facial swelling, or an incidental finding in 5% (1 of 20) each. Forty-five percent (9 of 20) underwent treatment, with all experiencing symptom resolution or improvement. Surgery included transvenous coil embolization in 33.3% (3 of 9), flap reconstruction in 22.2% (2 of 9), and surgical packing, ligation, and thrombectomy in 11.1% (1 of 9) each. Dilated MEV was reported concurrently with impeded drainage pathways in 35% (7 of 20) of reports. CONCLUSIONS: Dilated MEV has been reported as an etiology of pulsatile tinnitus and appears amenable to treatment via open and endovascular means. Endovascular coil embolization appears to offer effective symptom resolution, however, available literature exists only in case reports and small series. Further investigation is highly warranted.
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Acúfeno , Prótesis Vascular/efectos adversos , Senos Craneales , Dilatación Patológica/complicaciones , Humanos , Venas Yugulares , Apófisis Mastoides/diagnóstico por imagen , Apófisis Mastoides/cirugía , Acúfeno/cirugía , Acúfeno/terapiaRESUMEN
BACKGROUND: The cerebrovascular anatomy varies, with many associated variants and persistent channels. Many such vessels have been reported to carry an increased risk of intracranial aneurysm (IA) formation. We conducted a systematic literature review of IAs associated with variant anatomy. METHODS: We performed a systematic review without a meta-analysis in accordance with the PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines for studies involving IA formation in patients with variant anatomy. Studies were excluded if 1) the IAs were associated with malformations; 2) the variant anatomy discussed was in the form of segment hypoplasia or aplasia; 3) the anatomical variants were discussed secondary to the intervention; 4) insufficient information had been included; or 5) they were literature reviews. RESULTS: A total of 64 studies had met the inclusion and exclusion criteria for the final review. IA rupture was present in 91 of 131 cases (69.5%). Of the 131 IAs, 45 (34.3%) had been associated with an anomalous vessel origin or course, 43 with segmental fenestration (32.8%), 26 with a primitive persistent anastomosis (19.8%), and 17 with multiple or accessory vessels (12.9%). A total of 122 IAs (93.1%) had been treated with endovascular (64 of 122; 52.5%), microsurgical (57 of 122; 43.5%), or combined (1 of 122; 0.8%) methods. CONCLUSIONS: Variant, anomalous, and persistent primitive anatomy have often been reported in association with IA formation. These lesions present with a high proportion of rupture and warrant a low threshold for treatment. Preservation of perfusion is critical because such vessels developmentally exist to maintain flow.
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Aneurisma Roto , Aneurisma Intracraneal , Aneurisma Roto/cirugía , Humanos , Aneurisma Intracraneal/complicaciones , Aneurisma Intracraneal/diagnóstico por imagen , Aneurisma Intracraneal/cirugíaRESUMEN
Hakuba's triangle is a superior cavernous sinus triangle that allows for wide and relatively safe exposure of vascular and neoplastic lesions. This study provides cadaveric measurements of the borders of Hakuba's triangle and describes its neurovascular contents in order to enrich the available literature. The anatomical borders of the Hakuba's triangle (lateral, medial, and posterior borders) were defined based on Hakuba's description and identified. Then the triangle was dissected to reveal its morphology and relationship with adjacent neurovascular structures in Embalmed Caucasian cadaveric specimens. The oculomotor nerve occupied roughly one-third of the area of the triangle and the nerve was more or less parallel to its medial border. The mean lengths of the lateral border, posterior border, and medial border were 17 mm ± 0.5 mm, 12.2 mm ± 0.4 mm, and 10.6 mm ± 0.4 mm, respectively. The mean area of Hakuba's triangle was 63.9 mm2 ± 4.4 mm2. In this study, we provided cadaveric measurements of the borders of Hakuba's triangle along with descriptions of its neurovascular contents.
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Seno Cavernoso , Base del Cráneo , Cadáver , Arteria Carótida Interna/anatomía & histología , Seno Cavernoso/anatomía & histología , Humanos , Base del Cráneo/anatomía & histología , Base del Cráneo/cirugíaRESUMEN
OBJECTIVE: The venous plexus (internal carotid venous plexus) surrounding the petrous part of the internal carotid artery (ICAp) is said to be one drainage pathway of the cavernous sinus. These veins have many potential clinical implications including iatrogenic hemorrhage during surgical approaches to the skull base and carotid-cavernous fistulas. Because there are few morphological data about this venous plexus at the skull base, this descriptive/quantitative study was performed to elucidate its anatomy. METHODS: Six latex-injected cadaveric heads (twelve sides) were dissected via a superior craniotomy approach in which the ICAp was exposed by drilling away the overlying bone. A venous plexus surrounding parts of the ICAp in all sides was documented along with the positions of its major tributaries and their connections. RESULTS: The veins were most concentrated near the junction of the ICAp and the cavernous part of the internal carotid artery, and usually along the medial and lateral sides of the ICAp. Tributaries included branches joining the basilar venous plexus posteriorly and branches joining the veins surrounding the foramen ovale anteriorly. CONCLUSION: Detailed knowledge of the anatomy of this venous plexus surrounding the ICAp is useful for interpreting imaging of the skull base and valuable for surgeons operating in this part of the cranium.