Deconstruction of the Surgical Approach to the Jugular Foramen Region: Anatomical Study

Microsurgical resection of a samii type D jugular foramen schwannoma via the carotid triangle without removal of bony structure: how I do it

BACKGROUND

Samii Type-D jugular foramen schwannomas (JFSs) are the most challenging for neurosurgeons because of anatomical complexity. Various neurosurgical approaches have been described to gain access to JF.

METHODS

We present a female with incidental diagnosis of the Type-D JFS. Complete radical resection was achieved via the carotid triangle approach without any bony structure removal. And the patient was discharged asymptomatic and without new-developed neurological deficits.

CONCLUSIONS

The carotid triangle is a secure and appropriate approach for some cases of selected Type-D JFSs. However, the specific indications of this approach should be further explored and investigated.

Jugular Foramen Paragangliomas

Paragangliomas are the most common tumors at jugular foramen and pose a great surgical challenge. Careful clinical history and physical examination must be performed to adequately evaluate neurological deficits and its chronologic evolution, also to delineate an overview of the patient performance status. Complete imaging evaluation including MRI and CT scans should be performed, and angiography is a must to depict tumor blood supply and sigmoid sinus/internal jugular vein patency. Screening for multifocal paragangliomas is advisable, with a whole-body imaging. Laboratory investigation of endocrine function of the tumor is necessary, and adrenergic tumors may be associated with synchronous lesions. Preoperative prepare with alpha-blockage is advisable in norepinephrine/epinephrine-secreting tumors; however, it is not advisable in exclusively dopamine-secreting neoplasms. Best surgical candidates are young otherwise healthy patients with smaller lesions; however, treatment should be individualized each case. Variations of infratemporal fossa approach are employed depending on extensions of the mass. Regarding facial nerve management, we avoid to expose or reroute it if there is preoperative function preservation and prefer to work around facial canal in way of a fallopian bridge technique. If there is preoperative facial nerve compromise, the mastoid segment of the nerve is exposed, and it may be grafted if invaded or just decompressed. A key point is to preserve the anteromedial wall of internal jugular vein if there is preoperative preservation of lower cranial nerves. Careful multilayer closure is essential to avoid at most cerebrospinal fluid leakage. Residual tumors may be reoperated if growing and presenting mass effect or be candidate for adjuvant stereotactic radiosurgery.

Surgical treatment of selected tumors via the navigated minimally invasive presigmoidal suprabulbar infralabyrinthine approach without rerouting of the facial nerve

The feasibility of a novel skull base approach - the navigated minimally invasive presigmoidal suprabulbar infralabyrinthine approach (NaMIPSI-A) without rerouting of the fallopian canal for selected jugular foramen tumors (JFTs) - has been demonstrated in a neuroanatomical laboratory study. Here, we present our clinical experience with the NaMIPSI-A for selected JFTs, with a particular focus on its efficacy and safety. All patients with JFTs who were treated via the NaMIPSI-A were included in this study. The JFTs were classified according to a modified Fisch classification. The neurological and neuroradiological outcome, the extent of tumor resection, and the approach-related morbidity were examined. Five patients (two women, three men; mean age 57 years, range 48-65) were available. According to the modified Fisch classification, two JFTs were graded as C1, one as De1, and two as De2. Gross total resection (GTR) was achieved in three patients and near-total resection (NTR) in two. Postsurgically, no new neurological deficits and no approach-related morbidity and mortality occurred. One case with a postoperative cerebrospinal fluid leak was managed successfully with lumbar drainage. During the follow-up period (mean 67.6 months, range 12-119 months), tumor recurrence was noted in the NTR group but not in the GTR group. The NaMIPSI-A to the jugular foramen without rerouting of the fallopian canal is highly valuable for selected tumors of the jugular foramen. It is less invasive than other skull base approaches, and it allows safe and complete tumor removal in appropriate patients.

Simplifying the Surgical Classification and Approach to the Posterolateral Skull Base and Jugular Foramen Using Anatomical Triangles

Introduction Lesions of the jugular foramen (JF) and postero-lateral skull base are difficult to expose and exhibit complex neurovascular relationships. Given their rarity and the increasing use of radiosurgery, neurosurgeons are becoming less experienced with their surgical management. Anatomical factors are crucial in designing the approach to achieve a maximal safe resection. Methods and methods Six cadaveric heads (12 sides) were dissected via combined post-auricular infralabyrinthine and distal transcervical approach with additional anterior transstyloid and posterior far lateral exposures. Contiguous surgical triangles were measured, and contents were analyzed. Thirty-one patients (32 lesions) were treated surgically between 2000 and 2016 through different variations of the retro-auricular distal cervical transtemporal approaches. Results We anatomically reviewed the carotid, stylodigastric, jugular, condylar, suboccipital, deep condylar, mastoid, suprajugular, suprahypoglossal (infrajugular), and infrahypoglossal triangles. Tumors included glomus jugulare, lower cranial nerve schwannomas or neurofibromas, meningiomas, chondrosarcoma, adenocystic carcinoma, plasmacytoma of the occipitocervical joint, and a sarcoid lesion. We classified tumors into extracranial, intradural, intraosseous, and dumbbell-shaped, and analyzed the approach selection for each. Conclusion Jugular foramen and posterolateral skull base lesions can be safely resected through a retro-auricular distal cervical lateral skull base approach, which is customizable to anatomical location and tumor extension by tailoring the involved osteo-muscular triangles.

The Asterion-to-Transverse Process of the Atlas Line as a Surgical Landmark

Introduction Proposed landmarks to predict the anatomical location and trajectory of the sigmoid sinus have varying degrees of reliability. Even with neuronavigation technology, landmarks are crucial in planning and performing complex approaches to the posterolateral skull base. By combining two major dependable structures—the asterion (A) and transverse process of the atlas (TPC1)—we investigate the A-TPC1 line in relation to the sigmoid sinus and in partitioning surgical approaches to the region.

Methods We dissected six cadaveric heads (12 sides) to expose the posterolateral skull base, including the mastoid and suboccipital bone, TPC1 and suboccipital triangle, distal jugular vein and internal carotid artery, and lower cranial nerves in the distal cervical region. We inspected the A-TPC1 line before and after drilling the mastoid and occipital bones and studied the relationship of the sigmoid sinus trajectory and major muscular elements related to the line. We retrospectively reviewed 31 head and neck computed tomography (CT) angiograms (62 total sides), excluding posterior fossa or cervical pathologies. Bone and vessels were reconstructed using three-dimensional segmentation software. We measured the distance between the A-TPC1 line and sigmoid sinus at different levels: posterior digastric point (DP), and maximal distances above and below the digastric notch.

Results A-TPC1 length averaged 65 mm and was posterior to the sigmoid sinus in all cadaver specimens, coming closest at the level of the DP. Using the transverse-asterion line as a rostrocaudal division and skull base as a horizontal plane, we divided the major surgical approaches into four quadrants: distal cervical/extreme lateral and jugular foramen (anteroinferior), presigmoid/petrosal (anterosuperior), retrosigmoid/suboccipital (posterosuperior), and far lateral/foramen magnum regions (posteroinferior). Radiographically, the A-TPC1 line was also posterior to the sigmoid sinus in all sides and came closest to the sinus at the level of DP (mean, 7 mm posterior; range, 0–18.7 mm). The maximal distance above the DP had a mean of 10.1 mm (range, 3.6–19.5 mm) and below the DP 5.2 mm (range, 0–20.7 mm).

Conclusion The A-TPC1 line is a helpful landmark reliably found posterior to the sigmoid sinus in cadaveric specimens and radiographic CT scans. It can corroborate the accuracy of neuronavigation, assist in minimizing the risk of sigmoid sinus injury, and is a useful tool in planning surgical approaches to the posterolateral skull base, both preoperatively and intraoperatively.

Anatomical study of a surgical approach through the neck to the jugular foramen under endoscopy

OBJECTIVES

To investigate the feasibility of an endoscopic surgical approach through the neck to the jugular foramen, to determine the relevant techniques and extent of exposure, and to provide a new surgical approach with minimal trauma.

METHODS

Nine cadaveric head specimens with attached necks were fixed with 10% formalin solution. Two of the heads were fixed and injected with colored silicone rubber. Through the dissection of these cadaver head and neck specimens, we designed a surgical approach from the neck to the jugular foramen area with the use of a neuroendoscope and performed simulated surgery to determine which anatomical structures were encountered in the approach.

RESULTS

The posterior aspect of the internal jugular vein is adjacent to the rectus capitis lateralis. The internal carotid artery is anteromedial to the internal jugular vein, with the glossopharyngeal nerve, accessory nerve, vagus nerve and hypoglossal nerve in between. Removal of the rectus capitis lateralis can reveal the jugular process, and exposing the space between the superior oblique muscle and the jugular process can reveal the atlanto-occipital joint. Drilling through the occipital condyle can facilitate entrance into the skull, expose the flank of the medulla oblongata, and reveal the medullary olive and accessory nerve, vagus nerve, hypoglossal nerve, vertebral artery and posterior inferior cerebellar artery. Removing the jugular vein and completely opening the posterior wall of the jugular foramen can expose the inferior wall of the jugular bulb and the inferior wall of the sigmoid sinus. Drilling through the styloid process, which is lateral to the internal jugular vein, can expose the lateral area and upper wall of the jugular bulb and cranial nerves (CN) IX-XII; and near the top of the jugular bulb, the tympanic cavity and the external auditory canal can be easily opened.

CONCLUSION

Endoscopic surgical access from the neck to the jugular foramen is feasible. This surgical approach can simultaneously remove intracranial and extracranial tumors and can also be used to remove tumors in the ventral region of the occipital foramen and the hypoglossal canal. Furthermore, this approach is advantageous in that minimal trauma is inflicted. With judicious patient selection, this approach may have significant advantages and may be used as a primary or secondary surgical approach in the future. Nonetheless, this approach is still in development in a laboratory setting, and further research and improvements are needed before facing more complicated situations in clinical practice.