Figure 3 - uploaded by Amin Kassam
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The upper internal carotid artery and the cervical portions of cranial nerves IX through XII are mobilized anteriorly and the vertebral artery is mobilized posteriorly to open the carotid-vertebral window. This maneuver provides access to the tip of the dens (not shown). The sigmoid sinus is divided to provide access to the rostral aspect of the tumor. (PICA = posterior inferior cerebellar artery.)
Source publication
We describe a unique method of accessing the ventromedial skull base and lower craniocervical junction. Our method employs a trajectory between that of the more anterior transoral or retropharyngeal approaches and the various posterior or posterolateral skull base approaches. This "extended" lateral approach allows surgeons to resect very large tum...
Context in source publication
Context 1
... as we moved caudally, we observed that the tumor had extended toward the dens, which necessitated a ventral access that would not be possible with a posterolateral approach alone. The previously isolated lower cranial nerves and the upper portion of the internal carotid artery were then gently mobilized anteriorly, and the untethered vertebral artery was retracted posteriorly ( figure 3). This maneuver is the key to achieving the desired exposure, and it greatly enhances access to the clivus and to the most medial portion of the occipital condyle, which we resected up to the hypoglossal canal. ...
Citations
... A similar corridor was described by Kassam et al in which he used the so-called "carotid-vertebral space" to reach the ventromedial cranial base and lower craniocervical junction to operate on a hemangiopericytoma with a similar but bigger incision. 27 As previously described, using the natural corridors between the cervical and nuchal muscles avoids sharp dissection that could result in vascular lesions of the VA, the IJV, or the OA. 22 Therefore, thorough knowledge of the muscular relationships in the area helps to identify key structures such as the occipital condyle, the horizontal, and vertical V3 segment of the VA through the identification of the condylar, subatlantic, and suboccipital triangles, respectively. ...
Objectives The aim of this study was to describe the anatomical nuances, feasibility, limitations, and surgical exposure of the parapharyngeal space (PPS) through a novel minimally invasive keyhole endoscopic-assisted transcervical approach (MIKET).
Design Descriptive cadaveric study.
Setting Microscopic and endoscopic high-quality images were taken comparing the MIKET approach with a conventional combined transmastoid infralabyrinthine transcervical approach.
Participants Five colored latex-injected specimens (10 sides).
Main Outcome Measures Qualitative anatomical descriptions in four surgical stages; quantitative and semiquantitative evaluation of relevant landmarks.
Results A 5 cm long inverted hockey stick incision was designed to access a corridor posterior to the parotid gland after independent mobilization of nuchal and cervical muscles to expose the retrostyloid PPS. The digastric branch of the facial nerve, which runs 16.5 mm over the anteromedial part of the posterior belly of the digastric muscle before piercing the parotid fascia, was used as a landmark to identify the main trunk of the facial nerve. MIKET corridor was superior to the crossing of the accessory nerve over the internal jugular vein within 17.3 mm from the jugular process. Further exposure of the occipital condyle, vertebral artery, and the jugular bulb was achieved.
Conclusion The novel MIKET approach provides in the cadaver straightforward access to the upper and middle retrostyloid PPS through a natural corridor without injuring important neurovascular structures. Our work sets the anatomical nuances and limitations that should guide future clinical studies to prove its efficacy and safety either as a stand-alone procedure or as an adjunct to other approaches, such as the endonasal endoscopic approach.
Background:
Hemangiopericytomas (HPCs) and solitary fibrous tumors (SFTs), are rare tumors of mesenchymal origin. Here, the authors present a rare case of anaplastic HPC in the jugular foramen (JF). The authors also conduct a systematic review of the literature to examine the current fund of knowledge on JF HPC/SFTs.
Methods:
A systematic MEDLINE search was conducted using keywords 'hemangiopericytoma' OR 'solitary fibrous tumor' AND 'jugular foramen' OR 'extracranial OR 'skull base'. Clinicopathological characteristics and outcomes of the present case were reviewed and compared to those in the literature.
Results:
A 41-year-old male who had undergone stereotactic radiation therapy 6 years ago for a presumed glomus jugulare tumor, presented to our institution with worsening dysphagia, hoarseness, persistent tongue weakness and radiographic evidence of tumor progression. The patient underwent uncomplicated gross total resection with sacrifice of the infiltrated hypoglossal nerve. Histopathological evaluation revealed anaplastic HPC/SFT (WHO grade III). Review of the literature yielded 9 additional cases of JF HPC/SFT in 5 males (56%) and 4 females (44%), with a mean age of 49.6 years-old. Patients commonly presented with pain (37.5%) and lower cranial nerve (CN) deficits (100%). Preoperative diagnoses included glomus jugulare (n=2) or JF schwannomas (n=3). All patients underwent microsurgical resection of the lesion, except for one who refused all treatment after diagnostic biopsy.
Conclusion:
The authors present the only reported case of anaplastic HPC of the JF. The illustrative case and those found on systematic review of the literature highlight the importance of tissue diagnosis and appropriate management.
Aim
In recent years, extended endoscopic endonasal approach (EEEA) has been used as an alternative to transcranial approaches in the treatment of anterior midline skull base lesions. We retrospectively reviewed our cases operated using this technique and compared the results with current literature.
Method
The data of 24 patients who were operated using EEEA in our department between 2010-2018 were retrospectively analyzed. The lesions were located in the midline between the posterior wall of the frontal sinus and tuberculum sella. Tumor locations, histopathological diagnoses, surgical techniques, outcomes and complications were documented.
Results
Eleven patients were female and 13 were male. Their ages ranged between 18-75 years (mean 40.5 years). Considering their locations; 12 were in the anterior fossa (50%), 7 were in the tuberculum sella (29.1%), and 5 were in both anatomic sites (20.8%). Histopathologically, our series consisted of 15 meningiomas, 6 osteomas, 2 dermoid tumors and 1 metastatic carcinoma. We achieved gross total resection in 75% of our patients. Ten patients presented with visual complaints and 7 of them improved postoperatively. Postoperative cerebrospinal fluid leakage (CSF) was observed in 3 patients and one of them developed meningitis and subsequently died of sepsis.
Conclusion
Although the number of cases is low, EEEA seems like a safe, effective and well-tolerated treatment modality for anterior midline skull base lesions. But strict preventive measures should be taken for a possible CSF leak.
The first high cervical anterolateral retropharyngeal (HCALR) approach was reported by Stevenson et al. for a clivus chordoma in 1966. Anterior approaches to the spine have often been developed in response to problems presented by tuberculous spondylitis. This approach is indicated in anterior high cervical spine cases such as tumour resection, abscess drainage, atlantoaxial subluxation; decompression and stabilization. To our knowledge, only 21 papers in the literature have mentioned this approach. Its main advantage over posterior approaches is easy positioning and minimal need for soft tissue dissection. The HCALR approach provides wide exposure (of the anterior upper cervical spine, lower clivus and brainstem region) and feasibility for instrumentation. The limited space in which important neurovascular and visceral structures course and overlap contributes to the complexity of the anatomy. Navigating this intricate anatomy is essential for the safety of this approach and has been a drawback for utilization of the retropharyngeal corridor. This approach is one of the safest and most effective methods available to access the craniocervical junction. The benefits clearly outweigh the risks and complications.
Clival chordomas are rare tumors, especially in the pediatric population. In this report, we present the case of a 3-year-old boy who was found to have a large posterior pharyngeal, clival, and posterior fossa tumor detected on a CT scan after a closed head injury.
Further questioning revealed a history of ataxia and dysphagia. Imaging confirmed severe extrinsic brain stem compression. The tumor was resected in multiple stages utilizing a minimally invasive endoscopic endonasal technique along with open transfacetal, transcondylar approach through the carotid-vertebral window. The child suffered no permanent complications as a result of our treatment and his dysphagia significantly improved. Although a complete resection was not feasible due to vascular encasement by the tumor, extensive decompression was obtained with minimal morbidity.
We present this case to illustrate a new paradigm of skull base surgical approaches for large clival lesions in pediatric patients that allows aggressive resection with minimal morbidity.
