Case Report: A Case Series Using Natural Anatomical Gaps—Posterior Cervical Approach to Skull Base and Upper Craniocervical Meningiomas Without Bone Removal

Abstract

Background: Removal of anteriorly located tumors of the upper cervical spine and craniovertebral junction (CVJ) is a particular surgical challenge. Extensive approaches are associated with pain, restricted mobility of neck and head and, in case of foramen magnum and clivus tumors, with retraction of brainstem and cerebellum.Methods: Four symptomatic patients underwent resection of anteriorly located upper cervical and lower clivus meningiomas without laminotomy or craniotomy using a minimally invasive posterior approach. Distances of natural gaps between C0/C1, C1/C2, and C2/C3 were measured using preoperative CT scans and intraoperative lateral x-rays.Results: In all patients, safe and complete resection was conducted by the opening of the dura between C0/C1, C1/C2, and C2/C3, respectively. There were no surgical complications. Local pain was reported as very moderate by all patients and postoperative recovery was extremely fast. All tumors had a rather soft consistency, allowing mass reduction prior to removal of the tumor capsule and were well separable from lower cranial nerves and vascular structures.Conclusion: If tumor consistency is appropriate for careful mass reduction before removal of the tumor capsule and if tumor margins are not firmly attached to crucial structures, then upper cervical, foramen magnum, and lower clivus meningiomas can be safely and completely removed through natural gaps in the CVJ region. Both prerequisites usually become clear early during surgery. Thus, this tumor entity may be planned using this minimally invasive approach and may be extended if tumor consistency turns out to be less unfavorable for resection or if crucial structures cannot be easily separated from the tumor.

Craniocervical junction intradural extramedullary meningioma with cord compression

“…The search term “cranio-cervical junction meningioma” was used, and the case report/series filter was used. The results are described in table 1 8–11…”

Surgical corridors to foramen magnum meningiomas: a mini-review

“…Variations of this approach have been described according to the patient's position, skin incision, muscle reflection, and craniotomy. These variations include the far lateral, occipital transcondylar, atlantooccipital trans articular, supracondylar, trans tubercular, para condylar, and other minimally invasive approaches (12)(13)(14)(15)(16). Figure 1 represents some of these variations.…”

“…Frontiers in Neurology 04 frontiersin.org series of four patients (15). The minimally invasive supracondylar transtubercular approach uses a small S-shaped incision to resect a small portion of the occipital bone and drilling the posterior aspect of the occipital condyle and the superior facet joint of C1.…”

“…Minimally invasive approaches have been described, including variations of the transcondylar approach like the minimally invasive supracondylar trans tubercular approach to the lower clivus in cadaveric specimens ( 14 ) and a newly fashioned “Natural Anatomical Gaps-Posterior Cervical Approach,” recently described in a small series of four patients ( 15 ). The minimally invasive supracondylar transtubercular approach uses a small S-shaped incision to resect a small portion of the occipital bone and drilling the posterior aspect of the occipital condyle and the superior facet joint of C1.…”

“…In addition, with this approach, there is no need for removal or exposure of the C1 arch ( 14 ). On the other hand, the Natural Anatomical Gaps-Posterior Cervical approach is focused on saving bone resection given that the posterior aspect of the CVJ exhibits natural bony openings that may be used to access the upper cervical spinal canal, the foramen magnum, and the lower clivus, given the theoretical access supplied by the interspace between the occiput and the posterior arch of C1, C1 and the cranial edge of the lamina of C2, and between the lamina of C2 and the superior edge of the lamina of C3 ( 15 ). Unfortunately, this approach is suitable only for those patients with tumors not extending higher than the CVJ and a fairly mobile C-spine with sufficient width of the posterior bony gaps.…”