Transdural approach to resection of retro-odontoid cysts in elderly patients: report of 3 cases

Cervical Myelopathy Caused by Non-Rheumatic Retro-Odontoid Pseudotumor: An Investigation of Underlying Mechanisms and Optimal Surgical Strategy

STUDY DESIGN

Retrospective case-control study.

OBJECTIVE

This study aimed to identify the underlying pathologies of non-rheumatic retro-odontoid pseudotumors (NRPs), which would help establish an appropriate surgical strategy for myelopathy caused by NRP.

METHODS

We identified 35 patients with myelopathy caused by NRP who underwent surgery between 2006 and 2017. An age- and sex-matched control group of 70 subjects was selected from patients with degenerative cervical myelopathy. Radiographic risk factors for NRP were compared between cases and controls. We also assessed surgical outcomes following occipital-cervical (O-C) fusion, atlantoaxial (C1-2) fusion, or C1 laminectomy.

RESULTS

Patients with NRP had significantly lower C1 sagittal inner diameter, C2-7 range of motion (ROM), C2-7 Cobb angle, and C7 tilt, as well as significantly higher C1-2 ROM, atlantodental interval (ADI), and C1-2 to O-C7 ROM ratio. Multivariate regression analysis revealed that ADI, C2-7 ROM, and C7 tilt were independent risk factors for NRP. Neurological recovery and pseudotumor size reduction were comparable among surgical procedures, whereas post-operative cervical spine function was significantly lower in the O-C fusion group than in the other groups.

CONCLUSION

Non-rheumatic retro-odontoid pseudotumor was associated with an increase in ADI, suggesting that spinal arthrodesis surgery is a reasonable strategy for NRP. C1-2 fusion is preferable over O-C fusion because of the high prevalence of ankylosis in the subaxial cervical spine. Given that 29% of patients with NRP have C1 hypoplasia, such cases can be treated by posterior decompression alone. Our study highlights the need to select appropriate surgical procedures based on the underlying pathology in each case.

Transdural Approach for Resection of Craniovertebral Junction Cysts: Case Series

BACKGROUND

Craniovertebral junction (CVJ) cysts, including retro-odontoid pseudotumors, are challenging pathologies to treat and manage effectively. Surgical intervention is indicated when these lesions result in progressive myelopathy, intractable pain, or instability.

OBJECTIVE

To present a case series of older patients who underwent successful resection retro-odontoid lesions using transdural approach.

METHODS

A single-center, retrospective observation study of older patients who underwent transdural resection of CVJ cysts at a single institution was performed. Summary demographic information, clinical presentation, perioperative and intraoperative imaging, and Nurick scores were collected and analyzed.

RESULTS

Eight patients were included (mean age [±SD] 75.88 ± 9.09 years). All patients presented with retro-odontoid lesions resulting in severe cervical stenosis, cord compression, and myelopathy. The mean duration of surgery was 226 ± 83.7 minutes. The average intraoperative blood loss was 181.2 cc. The average hospital stay was 4.5 days ± 1.3 (range, 3-7 days). The average follow-up time was 12.5 ± 9.5 months. No intraoperative complications were encountered. The Nurick classification score for myelopathy improved at the final postoperative examination (2.38 ± 1.06 vs 1 ± 1.07). Three patients demonstrated a pre-existing deformity prompting an instrumented fusion. Both computed tomography and MRI evidence of complete regression of retro-odontoid cyst were noted in all patients on the final follow-up.

CONCLUSION

Posterior cervical transdural approach for ventral lesions at the CVJ is a safe and effective means of treating older patients with progressive myelopathy. This technique provides immediate spinal cord decompression while limiting neurological complications commonly associated with open or endoscopic anterior transpharyngeal approaches.

Atlantoaxial Intradural Synovial Cyst Mimicking an Extradural Lesion Adjacent to a Retro-odontoid Pseudotumor: A Case Report

Atlantoaxial synovial cysts can very rarely penetrate the dura mater into the thecal sac and cause direct neural compression. Several case reports have been available on "intradural synovial cysts" (IDSCs). In this study, we report on a case with an atlantoaxial IDSC mimicking an extradural lesion. A 90-year-old man was diagnosed with a cystic lesion located laterally to the atlantoaxial joint adjacent to the retro-odontoid pseudotumor (ROP) causing cervical spinal cord compression. Thus, surgical removal was planned. On preoperative examination, the cyst, which had a two-layer structure showing a T2-isointense small mass inside a T2-hyperintense lesion, was thought to be located in the extradural region. However, operative findings showed that the cyst was located inside the dura mater. Histopathological examination suggested a synovial cyst. No recurrence of the cyst was observed until the latest follow-up after 3 years, and the ROP decreased in size. Almost all IDSCs reported previously were observed in the medial site of the atlantoaxial joint. In our case, however, the cyst was observed adjacent to the posteromedial site of the right atlantoaxial joint and the ROP, mimicking an extradural lesion. We had no knowledge regarding the IDSC before the surgery and assumed an extradural lesion. Albeit rare, the existence of such a condition should be considered.

Calcium pyrophosphate dihydrate crystal deposition disease and retro-odontoid pseudotumor rupture managed via posterior occipital cervical instrumented fusion: illustrative case

BACKGROUND

Craniocervical junction and subaxial cervical spinal manifestations of calcium pyrophosphate deposition disease are rarely encountered. The authors presented a severe case of retro-odontoid pseudotumor rupture causing rapid quadriparesis and an acute comatose state with subsequent radiographic and clinical improvement after posterior occipital cervical fusion.

OBSERVATIONS

The authors surveyed the literature and outlined multiple described operative management strategies for compressive cervical and craniocervical junction calcium pyrophosphate deposition disease manifestations ranging from neck pain to paresthesia, weakness, myelopathy, quadriparesis, and cranial neuropathies. In this report, radiographic features of cervical and craniocervical junction calcium pyrophosphate deposition disease were explored. Several previously described surgical strategies were compiled, including patient characteristics and outcomes.

LESSONS

With this case report, the authors presented for the first time an isolated posterior occipital cervical fusion for treatment of a compressive retro-odontoid pseudotumor with rupture into the brainstem. They demonstrated rapid clinical and radiographic resolution after stabilization of cranial cervical junction only 12 weeks postsurgery.

Retro-Odontoid Intradural Synovial Cyst Decompression via Endoscopic-Assisted Far-Lateral Approach C1-C2 Hemilaminectomy Without Fusion: The Use of Intracranial Denticulate Ligament as Intraoperative Landmark

Purely intradural retro-odontoid synovial cysts are rarely reported in neurosurgical literature, particularly in the absence of associated bony erosions. We present the case of a 57-year-old Native American male with a retro-odontoid synovial cyst and a history of chronic refractory neck pain that was adequately decompressed via an endoscopic-assisted far-lateral approach using a C1-2 hemilaminectomy, obviating the vertebral artery (VA) transposition, bony instability, and the need for instrumented bony fusion. The patient presented to our clinic with several months of refractory nuchal and cervical spine pain and crepitation affecting his activities of daily living (ADL). MRI findings revealed an intradural cyst at the level of C2 behind the odontoid process impinging on the medulla and causing early VA displacement. Both stereotactic neuro-navigation and microsurgical visualization aided in the manipulation of the endoscope and attaining the caudocranial working trajectory. The patient remained neurologically non-lateralizing postoperatively, similar to his preoperative status. This article highlights a less invasive surgical exposure with an endoscope-assisted caudocranial trajectory obtained by a limited unilateral hemilaminectomy to achieve the desired outcome.

Surgical Management of Retro-Odontoid Cystic Mass with Cervicomedullary Compression

Retro-odontoid cysts are a rare cause of cervicomedullary compression. The etiology of these lesions is not completely understood. Previous trauma and instability at the cervicomedullary junction may be the precipitating event in the development of retro-odontoid cysts in rare cases. We discussed the neurosurgical evaluation of a patient who presented with progressive and rapid neurological deterioration secondary to cervicomedullary compression. Posterior occipitocervical fusion was performed. The patient made an excellent neurological recovery, and postoperative imaging studies demonstrated resolution of the compression and intramedullary cyst.

Cervical myelopathy caused by ventrally located atlanto-axial synovial cysts: An open quest for the safest and most effective surgical management. Case series and systematic review of the literature

OF BACKGROUND DATA

Despite a good understanding of the natural history of spinal synovial cysts (SCs), a widespread agreement regarding their optimal management is still lacking. This is particularly true for SCs occurring at the C1-C2 level, which are rare, but oftentimes lead to a rapidly evolving cervical myelopathy.

METHODS

We report a series of 4 patients (M:F ratio=1:1; mean age 63.5 years) presenting with progressive cervical myelopathy secondary to ventrally located C1-C2 SCs. All patients underwent a postero-lateral facet-sparing intradural approach with total excision of the SCs. Functional status was assessed pre- and postoperatively with Nurick scale and the modified Japanese Orthopaedic association grading. Furthermore we conducted a systematic review, following PRISMA guidelines of pertinent literature to contextualize the options for surgical management of such lesions.

RESULTS

Complete excision of the SCs was confirmed radiologically and on histological analysis. All measures of functional status improved post-operatively, and no cyst recurrence or need for instrumented fusion were noted during follow up (range from 22 to 88 months).

CONCLUSION

Our experience suggests that the facet-sparing intradural approach provides excellent clinical outcomes without causing any C1-C2 instability. This is in keeping with the take home message emerging from our literature review, which confirms that treatment should aim at radical resection of SCs while minimizing the risk of postoperative instability.

Transdural Approach to Resection of Intraspinal Extradural Ventral Cysts in the Lumbar Spine

BACKGROUND

Intraspinal extradural ventral cysts in the lumbar spine can cause back pain and neurological deficits of the lower extremities. For the resection of this type of space-occupying lesion, the transdural approach has not been reported in the literature.

CASE DESCRIPTION

A 66-year-old man presented, suffering from progressive radiation pain of his bilateral lower extremities. Imaging examination revealed a cystic lesion in ventral side of lumbar spinal canal. We conducted the excision of the cyst with the transdural approach. The symptoms of the patient disappeared immediately after the operation and recurrence of the symptoms has not been observed in the 3-month follow-up.

CONCLUSIONS

This operation approach is safe and effective. Compared with the previous surgical approach reported in the literature, by this approach surgeons could achieve less injury, shorter operation time, and the same surgical outcomes in the short term. Therefore, we would like to present this approach to provide an alternative to deal with similar lesions.

The posterior cervical transdural approach for retro-odontoid mass pseudotumor resection: report of three cases and discussion of the current literature

OBJECTIVE

The treatment of a retro-odontoid pseudotumor mass associated with severe spinal cord compression is challenging due to the complex regional anatomy. Here, we present an attractive treatment option involving a single-stage posterior transdural microsurgical resection followed by instrumented cervical reconstruction.

METHODS

We describe three patients presenting with clinical signs of cervical myelopathy and an imaging finding of mucoid and fibrous soft or semi-soft retro-odontoid pseudotumor mass with significant spinal cord compression at the C1/C2 level. Given the severity of the symptoms, surgical decompression was planned and fusion was necessitated by the severe degenerative osteoarthritis seen at the C1/C2 level with signs of instability. Using a standard posterior approach to the spine, a suboccipital decompression by craniectomy and laminectomy of C1, C2 and C3 was performed. The masses were visualized and confirmed with ultrasound imaging, and intraoperative neurosurgical monitoring was applied. The dura was then opened from the level of C0-C2. Exiting C2-C3 nerve roots were identified and protected throughout the procedure, and the dentate ligament was cut to facilitate access. Incision of the anterior dura provided easy access to the lesion for resection without any spinal cord retraction. Multiple intraoperative samples were sent to pathology for tissue diagnosis. The dura was closed with sutures and an overlay of fibrin sealant with collagen matrix sponge. The fusion procedures were performed using a standard occipital cervical plate and screws technique with contoured titanium rods.

CONCLUSIONS

The posterior cervical transdural approach is a safe alternative procedure for mucoid and fibrous soft or semi-soft retro-odontoid pseudotumor mass removal. Preoperative CT scan can evaluate tissue characteristics and distinguish between a soft or ossified mass in front of the spinal cord. Local anatomical conditions facilitate less bleeding and adhesions, together with less spinal cord traction, in the intradural space. Cranio-cervical and suboccipital stabilization can be easily and safely performed with this exposure.

Posterior transdural approach for odontoidectomy in a child: case report

The transoral transpharyngeal approach is the standard approach to resect the odontoid process and decompress the cervicomedullary spinal cord. There are some significant risks associated with this approach, however, including infection, CSF leak, prolonged intubation or tracheostomy, need for nasogastric tube feeding, extended hospitalization, and possible effects of phonation. Other ventral approaches, such as transmandibular and circumglossal, endoscopic transcervical, and endoscopic transnasal, are also viable alternatives but are technically challenging or may still traverse the nasopharyngeal cavity. Far-lateral and posterior extradural approaches to the craniocervical junction require extensive soft-tissue dissection. Recently, a posterior transdural approach was used to resect retro-odontoid cysts in 3 adult patients. The authors present the case of a 12-year-old girl with Down syndrome and significant spinal cord compression due to basilar invagination and a retro-flexed odontoid process. A posterior transdural odontoidectomy prior to occiptocervical fusion was performed. At 12 months after surgery, the authors report satisfactory clinical and radiographic outcomes with this approach.

Proximal Adjacent Segment Disease Manifesting as Retroodontoid Pseudotumor After Fusion to C2

BACKGROUND

Although adjacent segment disease (ASD) following anterior cervical fusion has been well described in the literature, there is relative paucity of data on this pathology after posterior cervical fusion. To our knowledge, there have been no reported cases of proximal ASD following posterior fusion to C2.

CASE DESCRIPTION

We present 2 cases of proximal ASD presenting as retroodontoid pseudotumors following posterior fusion to C2, both in middle-aged females without history of rheumatologic disease. The first occurred in a patient with Klippel-Feil deformity 13 years after C2-6 posterior cervical fusion, the second in a patient 3 and a half years following revisional circumferential C2-T2 fusion. Both were successfully treated with proximal extension of laminectomy and fusion to the occiput, supplemented in the first patient by transdural decompression of retroodontoid mass.

CONCLUSIONS

Proximal ASD can manifest as retroodontoid pseudotumor at variable time intervals following posterior fusion to C2. Clinicians must account for this possibility in their decision making.