Oblique transcorporeal approach to anteriorly located lesions in the cervical spinal canal

Subaxial cervical foraminal chondromas: case-based discussion on surgical management

Cervical foraminal chondromas are benign lesions that may require surgical resection when symptomatic due to radicular and/or spinal cord compression. The aim of surgery is to achieve gross tumor removal while preserving neurological function and spine stability. The authors describe a case of subaxial foraminal chondroma with a systematic review of the literature on patients with cervical chondromas. In the reported case, the authors used a retrojugular approach to remove a C6-C7 right chondroma without the need for spinal stabilization. Literature review identified a total of 11 patients who underwent surgery for subaxial foraminal chondroma. The mean age at diagnosis is 33.6 years (range: 10-73). Most patients report neurological symptoms at the time of diagnosis. The most frequently involved vertebral level is C4-C5 (54.6%, 6/11). Preoperative foraminal enlargement is present in 63.6% (7/11) of patients. Surgical resection is performed via an anterior approach in 18.2% (2/11) of patients, with vertebral body resection and concomitant cervical instrumentation. The anterolateral approach is selected in 27.2% (3/11) of patients, and the posterior approach in 54.6% (6/11) of patients, with only one patient requiring both anterior and posterior instrumentation. The choice of surgical access for subaxial foraminal chondroma can be challenging due to the anatomical location of the tumor in relation to the cervical nerve roots and spinal cord. Accurate approach selection is key to achieving complete tumor removal while preserving cervical spine stability.

Evaluating the effectiveness of the transcorporeal approach in minimally invasive spine surgery for cervical spinal disease: a comprehensive review and technical insights

BACKGROUND

The evolution of minimally invasive spine surgery, propelled by microscopy and endoscopy techniques, has reshaped the landscape of spinal interventions. The anterior approach to the cervical spine is widely recognized for its reproducibility and effectiveness in treating pathologies leading to radiculopathy or myelopathy. Apart from the traditional transdiscal approach, this study delves into the anterior transcorporeal approach, a minimally invasive technique, exploring its applicability in various cervical spinal pathologies.

PURPOSE

The objective is to comprehensively illustrate the anterior transcorporeal approach, exploring its historical development, biomechanical underpinnings, technical nuances, and clinical applications in managing cervical spine disorders.

METHODS

We conducted a comprehensive review using PubMed, Embase, Cochrane Library, and Web of Science, adhering to PRISMA guidelines. The search was focused on the minimally invasive anterior transcorporeal approach for cervical pathologies, with an emphasis on evaluating the methodological evolution, technical execution, and clinical outcomes across diverse studies.

RESULTS

The review identified a significant body of literature supporting the efficacy of the minimally invasive anterior transcorporeal approach. Over the past two decades, this approach has demonstrated encouraging clinical outcomes, suggesting its potential as an alternative strategy for specific cervical spine diseases. The evolution of this technique is tightly linked to the advancements in medical equipment and the innovative endeavors of surgical pioneers.

CONCLUSIONS

The anterior transcorporeal approach marks a milestone in minimally invasive cervical spine surgery. Its development reflects ongoing efforts to refine surgical techniques for better patient outcomes. While offering a promising alternative for treating certain cervical spine conditions, the approach demands precise case selection and is influenced by the rapid progression of medical technology. Future research and technological advancements are expected to further enhance the efficacy and safety of this approach, potentially expanding its indications in spinal surgery.

Anterior percutaneous full-endoscopic transcorporeal decompression for cervical disc herniation: a finite element analysis and long-term follow-up study

OBJECTIVE

The purpose of this study was to investigate the long-term consequences on the cervical spine after Anterior transcorporeal percutaneous endoscopy cervical discectomy (ATc-PECD) from the biomechanical standpoint.

METHODS

A three-dimensional model of the normal cervical spine C2-T1 was established using finite element method. Subsequently, a disc degeneration model and degeneration with surgery model were constructed on the basis of the normal model. The same loading conditions were applied to simulate flexion, extension, lateral bending and axial rotation of the cervical spine. We calculated the cervical range of motion (ROM), intradiscal pressure, and intravertebral body pressure under different motions for observing changes in cervical spine biomechanics after surgery. At the same time, we combined the results of a long-term follow-up of the ATc-PECD, and used imaging methods to measure vertebral and disc height and cervical mobility, the Japanese Orthopaedic Association (JOA) score and visual analog scale (VAS) score were used to assess pain relief and neurological functional recovery.

RESULTS

The long-term follow-up results revealed that preoperative JOA score, neck VAS score, hand VAS score, IDH, VBH, and ROM for patients were 9.49 ± 2.16, 6.34 ± 1.68, 5.14 ± 1.48, 5.95 ± 0.22 mm, 15.41 ± 1.68 mm, and 52.46 ± 9.36° respectively. It changed to 15.71 ± 1.13 (P < 0.05), 1.02 ± 0.82 (P < 0.05), 0.77 ± 0.76 (P < 0.05), 4.73 ± 0.26 mm (P < 0.05), 13.67 ± 1.48 mm (P < 0.05), and 59.26 ± 6.72° (P < 0.05), respectively, at 6 years postoperatively. Finite element analysis showed that after establishing the cervical spondylosis model, the overall motion range for flexion, extension, lateral bending, and rotation decreased by 3.298°, 0.753°, 3.852°, and 1.131° respectively. Conversely, after establishing the bone tunnel model, the motion range for these actions increased by 0.843°, 0.65°, 0.278°, and 0.488° respectively, consistent with the follow-up results. Moreover, analysis of segmental motion changes revealed that the increased cervical spine mobility was primarily contributed by the surgical model segments. Additionally, the finite element model demonstrated that bone tunneling could lead to increased stress within the vertebral bodies and intervertebral discs of the surgical segments.

CONCLUSIONS

Long-term follow-up studies have shown that ATc-PECD has good clinical efficacy and that ATc-PECD can be used as a complementary method for CDH treatment. The FEM demonstrated that ATc-PECD can lead to increased internal stresses in the vertebral body and intervertebral discs of the operated segments, which is directly related to cervical spine degeneration after ATc-PECD.

Surgical Essentials and 2-Year Follow-Up Results of Channel Repair in Endoscopic Transcorporeal Discectomy for Cervical Disc Herniation

OBJECTIVE

To evaluate long-term outcomes and surgical essentials of channel repair in endoscopic transcorporeal discectomy for cervical disc herniation.

METHODS

From October 2019 to March 2020, 24 patients with cervical disc herniation underwent channel repair after percutaneous full-endoscopic anterior transcorporeal cervical discectomy. Five interventions were performed at C3-C4, 11 were performed at C4-C5, and 8 were performed at C5-C6. Clinical outcomes were evaluated by Neck Disability Index, Japanese Orthopaedic Association, and visual analog scale scores. Radiologic changes were evaluated with intervertebral disc height and drilled vertebral height.

RESULTS

All procedures were completed with a mean operating time of 86.40 ± 8.19 minutes. Swollen neck was observed in 5 patients, which resolved within 2 hours. At the final follow-up, Neck Disability Index, Japanese Orthopaedic Association, and visual analog scale scores were improved significantly compared with preoperative assessments (P < 0.05); intervertebral disc height was decreased significantly (P < 0.05); and loss of drilled vertebral height was not significant (P > 0.05). All 24 bony channels disappeared by 3 months postoperatively. No other complications were observed.

CONCLUSIONS

Percutaneous full-endoscopic anterior transcorporeal cervical discectomy with channel repair offers a minimally invasive and effective treatment option for patients with cervical disc herniation. This technique demonstrates favorable clinical outcomes, including preservation of cervical spine mobility and minimal complications. Although there was a significant loss of intervertebral disc height, no vertebral collapse occurred. Strict adherence to surgical indications and precautions is crucial for successful outcomes. Further research and long-term studies are required to validate the efficacy and safety of this approach in a larger patient population.

Anterior transcorporeal approach combined with posterior translaminar approach in percutaneous endoscopic cervical discectomy for two-segment cervical disc herniation treatment: a technical report and early follow-up

OBJECTIVE

Full endoscopic techniques are being gradually introduced from single-segment cervical disc herniation surgery to two-segment cervical disc herniation surgery. However, there is no suitable full endoscopic treatment for mixed-type two-segment cervical disc herniation (MTCDH) in which one segment herniates in front of the spinal cord and the other segment herniates behind the spinal cord. Therefore, we introduce a new full endoscopic technique by combining an anterior transcorporeal approach and a posterior translaminar approach. In addition, we provide a brief description of its safety, efficacy, feasibility, and surgical points.

METHODS

Thirty patients with MTCDH were given full endoscopic surgical treatment by a combined transcorporeal and transforaminal approach and were followed up for at least 12 months.

RESULTS

Clinical assessment scales showed that the patient's symptoms and pain were significantly reduced postoperatively. Imaging results showed bony repair of the surgically induced bone defect and the cervical Cobb angle was increased. No serious complications occurred.

CONCLUSION

This technique enables minimally invasive surgery to relieve the compression of the spinal cord by MTCDH. It avoids the fusion of the vertebral body for internal fixation, preserves the vertebral motion segments, avoids medical destruction of the cervical disc to the greatest extent possible, and expands the scope of adaptation of full endoscopic technology in cervical surgery.

Lateral Approach to the Cervical Spine to Manage Degenerative Cervical Myelopathy and Radiculopathy

BACKGROUND

The cervical lateral approach can enlarge the spinal canal and foramen to achieve an effective neural decompression without needing spine stabilization. For this review, the authors' main objective was to illustrate the rationale, advantages, disadvantages, complications, and pitfalls of this technique, highlighting also areas for future development.

MATERIALS AND METHODS

A Medline via PubMed database search was carried out by using both keywords, namely "cervical oblique corpectomy," "multilevel oblique corpectomy and foraminotomy," and "lateral vertebrectomy," and Medical Subject Headings (MeSH) terms from 1 January 1991, up to 31 December 2021.

RESULTS

The analyzed articles suggested that the use of such a technique has declined over time; only 29 clinical studies met all the inclusion criteria and were retained for data analysis, including 1200 patients undergoing such an approach for the management of degenerative cervical myelopathies (DCMs) or of radiculopathies. The main etiopathogeneses were cervical stenosis, degenerative disk disease, or a mix of them-78% of which had a favorable outcome; the most frequent complications were transient and permanent Horner syndrome in 13.6% and 9.2% of cases, respectively. Long-term stability was reported in 97% of patients.

CONCLUSION

Multilevel cervical oblique vertebrectomy and/or lateral foraminotomy allow wide neural structure decompression and optimal stability given that the physiological spinal motion is preserved.

Case report: Anterior midline decompression of a cervical epidural abscess: Technical note and case series of seven patients

Background

A spinal epidural abscess (SEA) of the cervical spine is a relatively rare disease and is generally characterized by progressive neurological deterioration due to compression of the spinal cord. Up to 40% of cervical SEAs are located ventrally of the spinal cord. Urgent surgical intervention is warranted to decompress the spinal cord and collect material for cultures to guide antibiotic treatment. However, the optimal timing of the intervention is unclear, and the associated risk of spinal instability in the presence of an extensive infection is a significant clinical dilemma.

Methods

In this paper, we present a novel surgical technique to treat a cervical SEA by anterior decompression through a linear transvertebral midline approach. This technique has the advantage of effectively draining the ventrally located SEA and obtaining material for bacteria culture while maintaining spinal stability without additional instrumentation.

Results

This case study presents seven patients with cervical SEAs who were successfully treated with surgical decompression by this transvertebral linear midline technique and antibiotic treatment.

Conclusion

Anterior decompression through a linear transvertebral midline approach for a ventrally located cervical SEA is a safe and pragmatic surgical procedure to achieve spinal cord decompression and collect bacteria culture without destabilizing the cervical spine.

Far-Lateral Approach for Foramen Magnum Meningioma: An Anatomical Study with Special Reference to Bulbopontine Junction

Intracranial meningiomas are sometimes located anteriorly to the foramen magnum and can cause disabling long tract symptoms. The far-lateral approach has been developed to provide an extensive view over the bulbopontine junction and the surrounding lower cranial nerves and upper spinal nerves with a good control on the vertebral artery, allowing the safe resection of such tumors. It is the report of a case with anatomical study before and after the removal of the meningioma. The use of the far-lateral approach allowed us to (1) control the vertebral artery in its V3 (Atlantic extradural) and V4 (intradural) portion (2) have an optimal visibility on the lower cranial nerves, the upper spinal nerves, and the bulbopontine junction, and (3) perform a Simpson 2 resection of the tumor that was inserted between the lower clivus and the upper odontoid process. Beyond its interest for the safe resection of tumors located anteriorly to the foramen magnum, the far-lateral approach is of particular anatomical interest. It allowed us to review the anatomy of the craniocervical junction.

A Novel Technique of Endoscopic Anterior Transcorporeal Approach with Channel Repair for Adjacent Segment Disease After Anterior Cervical Discectomy and Fusion

OBJECTIVE

To first report the application of percutaneous full-endoscopic anterior transcorporeal cervical discectomy (PEATCD) with channel repair for a patient with adjacent segment disease (ASD) after anterior cervical discectomy and fusion.

METHODS

PEATCD with channel repair was performed for a patient with ASD at the cranial level adjacent to previous fusion at the C5-C6 level. The pre- and postoperative clinical symptoms were evaluated with Japanese Orthopedic Association and visual analog scale (VAS). The radiological examinations included magnetic resonance imaging, computed tomography, and plain radiographs, which were used to evaluate the cervical alignment, stability, intraoperative decompression, and bony channel.

RESULTS

The procedure was successfully completed within 70 minutes. The drainage tube was unnecessary. No surgery-related complications were recorded. The postoperative neck pain immediately improved to VAS 3 from preoperative VAS 6. The Japanese Orthopedic Association scores also took a turn for the better gradually from preoperative 10 to final 16 (improvement rate 85.7%). The muscle power recovered completely, and the Hoffman sign turned to negative during follow-up periods. Magnetic resonance imaging 1 week postoperatively showed a total removal of the herniation. The bony channel was almost disappeared on computed tomography images 3 months postoperatively. During postoperative periods, no relapse, channel collapse, bone plug migration, or instability was observed.

CONCLUSION

As a novel and supplemental procedure for ASD after anterior cervical discectomy and fusion, PEATCD combines the advantages of transcorporeal approach and endoscopy together, which decreases iatrogenic damage to disc, preserves the cervical motion segment, and reduces surgical trauma. As the limitations of 1 case show, the effectiveness and reliability of PEATCD for patients with ASD should be verified in further studies.

Cervical Oblique Corpectomy: Revitalizing the Underused Surgical Approach With Step-By-Step Simulation in Cadavers

ABSTRACT

Recently, the World Federation of Neurosurgical Societies Spine committee recommended that additional research on cost-benefit analysis of various surgical approaches for cervical spondylotic myelopathy be carried out and their efficacy with long-term outcomes be compared. Unfortunately, it is highly probable that the oblique corpectomy (OC) will not be included in cost-benefit investigations due to its infrequent application by neurosurgeons dealing with the spine. In this cadaveric study, head and necks of 5 adult human cadavers stained with colored latex and preserved in 70% alcohol solution were dissected under a table-mounted surgical microscope using 3× to 40× magnifications. The OC approach was performed to simulate real surgery, and the neurovascular structures encountered during the procedure and their relations with each other were examined. Oblique corpectomy was performed unilaterally, although neck dissections were performed bilaterally on 10 sides in all 5 cadavers. At each stage of the dissection, multiple three-dimensional photographs were obtained from different angles and distances. For an optimal OC, both the anterior spinal cord must be sufficiently decompressed and sufficient bone must be left in place to prevent instability in the cervical spine. Oblique corpectomy is a valid and potentially low cost alternative to other anterior and posterior approaches in the surgical treatment of cervical spondylotic myelopathy. However, meticulous cadaver studies are essential before starting real surgical practice on patients in order to perform it effectively and to avoid the risks of the technique.

Minimally Invasive Anterolateral Approach for C2 Neurofibroma in Elderly Patient

Conventionally ventrally located spinal tumor is approached through anterior vertebrectomy which requires bony fixation and then immobilization for a couple of months. The alternative route to deal with such type of tumor is anterolaterally to avoid the surgical and nonsurgical complications. We are reporting a minimally invasive anterolateral approach for C2 neurofibroma in an 84-year-old patient. Postoperatively this patient did not require cervical brace and postoperative discomfort was minimal. It was observed that dumbbell-shaped cervical tumor with no intradural pathology and wide neural foramina could also be taken care through the anterolateral route which did not require bony fusion or immobilization, but the expertise of the surgeon is necessary for performing these types of minimally invasive procedure to achieve the best results.

[Clinical study of single-level cervical disc herniation treated by full-endoscopic decompression via anterior transcorporeal approach]

OBJECTIVE

To investigate the clinical feasibility of full-endoscopic decompression for the treatment of single-level cervical disc herniation via anterior transcorporeal approach.

METHODS

According to the inclusion and exclusion criteria, 21 patients with cervical disc herniation who received full-endoscopic decompression via anterior transcorporeal approach between September 2014 and March 2016 were retrospectively analyzed. There were 12 males and 9 females with an age ranged from 32 to 65 years, with an average of 48.5 years. The duration of symptoms ranged from 6 to 18 weeks, with an average of 10.5 weeks. According to the Nurick grading of spinal cord symptoms, there were 2 cases with grade 1, 7 cases with grade 2, and 12 cases with grade 3. Operative segment was C 3, 4 in 2 cases, C 4, 5 in 8 cases, C 5, 6 in 9 cases, and C 6, 7 in 2 cases. The operation time and related complications were recorded. The central vertical height of the vertebral body and the diseased segment space were measured on the cervical X-ray film. The neck and shoulder pain were evaluated by visual analogue scale (VAS) score; Japanese Orthopaedic Association (JOA) score was used to evaluate the improvement of neurological function in patients. The MRI of cervical spine was reexamined at 3 months after operation, and the CT of cervical spine was reexamined at 12 months after operation. The decompression of spinal cord and the healing of bone canal in the vertebral body were further evaluated.

RESULTS

Full-endoscopic decompression via anterior transcorporeal approach were achieved at all 21 patients. The operation time was 85-135 minutes, with an average of 96.5 minutes. All patients were followed up 24-27 months, with an average of 24.5 months. There was no complication such as residual nucleus pulposus, spinal cord injury, large esophageal vessels injury, pleural effusion, endplate collapse, intraspinal hematoma, cervical spine instability, protrusion of disc in the same segment, or kyphosis. Both VAS scores of neck and shoulder pain and JOA scores were significantly improved at 12 months after operation ( P<0.05). At 3 months after operation, it was confirmed by the cervical MRI that neural decompression was sufficient and the abnormal signal was also degraded in the patients with intramedullary high signal at T2-weighted image. The cervical CT showed that bone healing were achieved in the surgical vertebral bodies of all patients at 12 months after operation. At 24 months after operation, the central vertical height of the diseased segment space significantly decreased compared with preoperative one ( t=2.043, P=0.035); but there was no significant difference in the central vertical height of the vertebral body between pre- and post-operation ( t=0.881, P=0.421).

CONCLUSION

Full-endoscopic decompression via anterior transcorporeal approach, integrating the advantages of the endoscopic surgery and the transcorporeal approach, provide an ideal and thorough decompression of the ventral spinal cord with satisfactory clinical and radiographic results.

Transcorporeal Tunnel Approach for Cervical Radiculopathy and Myelopathy: A Systematic Review and Meta-Analysis

OBJECTIVE

The transcorporeal tunnel approach is a relatively new alternative of anterior cervical decompression and fusion for the treatment of cervical radiculopathy and myelopathy, with its main presumed advantage being the preservation of the intervertebral space. The aim of the present article is to present the outcomes of the systematic review and meta-analysis regarding the short-term outcomes of this surgical technique.

METHODS

A systematic review and a meta-analysis using the random-effects method of the available studies were performed to assess the safety and efficiency of the transcorporeal tunnel approach for cervical radiculopathy and myelopathy.

RESULTS

In total, 15 eligible studies were identified, with a cumulative number of 254 patients. Pooled data yielded a complication rate of 0.053 and a failure rate of the technique of 0.081; a patient-reported favorable outcome of 0.94 was documented. The available data did not allow for a definite conclusion on the effects of the technique on the intervertebral space height.

CONCLUSIONS

Although technically challenging, like all minimally invasive methods, the transcorporeal tunnel approach seems to be a safe and efficient option for the treatment of cervical radiculopathy and myelopathy, presenting comparable outcome profiles to alternative open or less invasive techniques.

Anterior percutaneous full-endoscopic transcorporeal decompression of the spinal cord for single-segment cervical spondylotic myelopathy: The technical interpretation and 2 years of clinical follow-up

BACKGROUND

ACDF is the standard procedure for treatment of cervical spondylotic myelopathy (CSM), but a long-term follow-up has been revealed some associated complications of swallowing discomfort, displacement of the fusion device, and accelerated degeneration of the adjacent segment.

OBJECTIVE

To evaluate the clinical outcomes of anterior percutaneous full-endoscopic transcorporeal decompression of the spinal cord (APFETDSC) for single-segment CSM and to analyze the clinical efficacy, surgical characteristics, and complication prevention.

METHODS

A total of 32 patients who underwent APFETDSC for single-segment CSM from Aug. 2015 to Apr. 2017 were reviewed. Operating time, time of walking out of bed postoperation, length of hospitalization, complications, neck pain visual analog scale (VAS), and Japanese Orthopaedic Association Score (JOA) were evaluated. Measurement of intervertebral height (HI) of surgical segments on cervical neutral X-ray, Harrison's method was used to measure cervical spine angle (CSA).

RESULTS

The operation time was 103.3 ± 12.95 min, time of walking out of bed after surgery was 19.81 ± 4.603 h, the length of postoperative hospital stay was 57.48 ± 19.48 h. The postoperative neck pain VAS and JOA were significantly improved compared with preoperation(p < 0.001). The postoperative HI was statistical significance decreased compared with preoperation(p < 0.001), but the HI reduction was less than 0.5 mm, without adverse clinical symptoms. The postoperative CSA was significantly improved compared with preoperative(p < 0.001). The excellent and good rate was 87.5%, and the JOA improvement rate was 75.52 ± 11.11%. There was no cervical instability, vertebral fracture, wound infection, and other complications.

CONCLUSIONS

APFETDSC is a safe and effective minimally invasive technique with small auxiliary injuries for single-segment CSM while avoiding the sequelae of ACDF. Its short-term clinical efficacy was good and no significant effect on cervical stability.

Anterior Surgical Techniques for Cervical Spondylotic Myelopathy: WFNS Spine Committee Recommendations

Objective

This study was performed to review the literature and to present the most up-to-date information and recommendations on the indications, complications, and success rate of anterior surgical techniques for cervical spondylotic myelopathy (CSM). The commonly performed anterior surgical procedures are multiple-level anterior cervical discectomy and fusion, anterior cervical corpectomy and fusion and its variants (skip corpectomy and hybrid surgery), and oblique corpectomy without fusion.

Methods

A comprehensive literature search and analysis were performed using MEDLINE (PubMed), the Cochrane Register of Controlled Trials, and the Web of Science for peer-reviewed articles published in English during the last 10 years.

Results

Corpectomy is mandated for ventral compression of fewer than 3 vertebral segments where single-level disc and osteophyte excision is inadequate to decompress the cord. Endoscopic or oblique partial corpectomy improves the sagittal canal diameter by 67% and obviates the need for an additional bone graft procedure.

Conclusion

The indications of anterior surgery in patients with CSM include a straightened or kyphotic spine with a compression level lower than 3. With an appropriate choice of implants and meticulous surgical technique, surgical complications can be seen only rarely. Improvements after anterior surgery for CSM have been reported in 70% to 80% of patients.

Cervical endoscopic spinal surgery: A review of the current literature

Cervical endoscopic spinal surgery (CESS) is now regularly performed in some centres in the Far East, yet rarely in Europe and the United States. This review describes the application of CESS through anterior and posterior approaches with analysis of the available evidence supporting current techniques. An electronic literature search identified 52 papers and proceedings' abstracts of which 25 (16 anterior approach and 9 posterior approach) provided comparable clinical outcomes. The results revealed a good or excellent outcome from CESS in 91% (range 74-100%) with a complication rate of 5%. In a local cohort study, patients had 72% less neck pain (visual analogue scale rating) and 81% less arm pain at 6 months when CESS was used as an isolated procedure, and 74% less neck pain and 83% less arm pain when coupled with disc replacement or fusion at an adjacent level.

Percutaneous full-endoscopic anterior transcorporeal cervical discectomy and channel repair: a technique note report

Background

Compared to anterior cervical discectomy and fusion (ACDF), cervical motion segment and disc was retained through anterior transcorporeal herniotomy (ATH). But surgical field and manipulation in traditional ATH was restricted by the narrow channel. Percutaneous full-endoscopic transdiscal cervical discectomy is a minimally invasive and functional spine surgery. However, significant loss of intervertebral disc height was inevitable. This study was done to illustrate the feasibility, safety, and efficacy and present our surgical experience of percutaneous full-endoscopic anterior transcorporeal cervical discectomy (PEATCD) and channel repair (CR) for the treatment of cervical disc herniation (CDH).

Methods

Four patients with CDH were chosen to undergo PEATCD and CR with a follow-up care for at least 22 months. The visual analogue score (VAS), Japanese Orthopedic Association (JOA), and modified Macnab criteria were recorded during the postoperative periods. CT images were obtained to observe the healing of the channel at 1 week and 3 months after the operation.

Results

The average operating time was 83.75 min. Drainage tubes were unnecessary. No procedure-related complications occurred. The postoperative VAS and JOA scores were improved compared to those of the preoperative assessment. The clinical efficacy was excellent in 3 patients and good in 1 patient at final follow up stage according to the modified Macnab criteria. The hernia was removed completely in all patients according to postoperative MRI. Migration of the repair implementation and collapse of the drilled vertebrae were not observed during the postoperative periods. The bony channel was nearly absent on CT images obtained at 3 months postoperative.

Conclusion

This is the first time that the anterior transcorporeal cervical discectomy and CR have been performed simultaneously under endoscopy. Less damage to disc and the retained cervical motion segment were achieved through this method. This is a feasible, safe, and minimally invasive procedure.

Trial registration

Numbers: ChiCTR1800016383. Registered 29 may 2018. Retrospectively registered. Trial registry: Chinese Clinical Trial Registry.

Electronic supplementary material

The online version of this article (10.1186/s12891-019-2659-0) contains supplementary material, which is available to authorized users.

Usage of Bone Wax to Facilitate Percutaneous Endoscopic Cervical Discectomy Via Anterior Transcorporeal Approach for Cervical Intervertebral Disc Herniation

BACKGROUND

Currently, anterior transdiscal access and posterior interlaminar approach are the main approaches for percutaneous endoscopic cervical discectomy (PECD). To overcome access shortcomings, we previously described a novel anterior endoscopic transcorporeal approach on a migrated cervical disc. We innovatively introduced bone wax into endoscopic surgery to aid hemostasis and facilitate the process of drilling an intracorporeal tunnel.

METHODS

Five patients with cervical intervertebral disc herniation (CIDH) were treated by PECD via the anterior transcorporeal approach. During the operation, we marked the punctured tunnel with bone wax containing indigo carmine as a guide and smeared bone wax on the endoscopic burr to aid hemostasis.

RESULTS

A satisfactory clinical outcome was observed in all 5 patients postoperatively; pain and neurologic condition were dramatically improved. Surgery-related complications, such as esophageal injury, vascular rupture, hematoma, intervertebral disc infection, or postoperative headache, were not encountered. A computed tomography scan was used to observe the process of bone healing. At 3-month postoperative follow-up, the bone defect within the drilling tunnel had partially shrank and was completely healed at 6 months postoperatively.

CONCLUSIONS

The anterior endoscopic transcorporeal approach for PECD is a novel, valuable alternative for the treatment of CIDH. Bone wax could indeed facilitate the operation by guiding the drilling process and instantly controlling the bleeding without obvious interference with bone healing. Long-term follow-up is warranted in further clinical studies.

Local Spinal Cord Decompression Through a Full Endoscopic Percutaneous Transcorporeal Approach for Cervicothoracic Ossification of the Posterior Longitudinal Ligament at the T1-T2 Level

OBJECTIVE

To describe a percutaneous full endoscopic transcorporeal procedure to excise local ossification of the posterior longitudinal ligament (OPLL) lesions and decompress the spinal cord at the cervicothoracic transitional segment is safe and effective with respect to surgical complications.

METHODS

A 67-year-old woman presented with nuchal pain and numbness below the T2 dermatome for 3 months and a 2-week history of paraplegia. T1-T2 myelopathy and paraplegia caused by OPLL was diagnosed based on clinical presentation, computed tomography, and magnetic resonance imaging. An anterior percutaneous full endoscopic transcorporeal procedure addressed local OPLL and achieved local spinal cord decompression at T1-T2. After surgery, magnetic resonance imaging was repeated to evaluate degree of spinal cord decompression. Visual analog scale, Neck Disability Index, and Japanese Orthopaedic Association scores were evaluated at each follow-up.

RESULTS

The patient tolerated the full endoscopic operation successfully. Operative time was 225 minutes. On postoperative day 6, muscle strength of the bilateral lower extremities had progressed from grade 0/5 preoperatively to grade 2-/5 on the right and grade 2+/5 on the left. No surgery-related complications were discovered.

CONCLUSIONS

The percutaneous full endoscopic transcorporeal procedure is an alternative to previously described surgical methods of local spinal cord decompression for T1-T2 OPLL with fewer complications, effective spinal cord decompression, and a satisfactory cosmetic result. Successful cases confirm that treatment of spinal cord-limited compression by endoscopic technology is feasible.

Oblique corpectomy for treatment of cervical spine epidural abscesses: Report on four cases

BACKGROUND

Spinal epidural abscesses (SEAs) in cervical locations are particularly life-threatening. Currently, SEAs are widely treated with bony decompression, followed by internal stabilization in purulent osteomyelitis. However, recently, a growing number of studies have reported minimally invasive approaches without internal fixation.

PURPOSE

We describe four patients with cervical SEAs that were evacuated by oblique corpectomy (OC) without fusion.

METHODS

This study included two women and two men (aged 44-90) that received operations for removing ventral cervical SEAs. All patients presented with progressively increasing myelopathy, and 3 had severe comorbid conditions. In all cases, a multilevel OC without fusion was performed. The amount of bone resection was tailored to fit the needs of granulation removal, with an effort to retain as much of the vertebral bodies as possible. Then, pus was evacuated and debridement of granulation was performed, followed by rinsing and drainage.

RESULTS

The neurological status of 3 patients improved significantly after surgery. At the last follow-up examination, one showed full recovery, and in two a minor residual deficit persisted. During mean follow-up of 5.5 years, no internal stabilization was necessary. The oldest patient was tetraplegic, and had several concomitant diseases. That patient died from sudden cardiac arrest on the third postoperative day. Oblique corpectomy did not affect the anterior or posterior column. Additionally, it provided a broad view of the ventral aspect of the spinal canal.

CONCLUSIONS

Oblique corpectomy allows appropriate spinal cord decompression and granulation removal in the case of cervical spine epidural abscess, without sacrificing spinal stability.

Anterior transcorporeal approach of percutaneous endoscopic cervical discectomy for disc herniation at the C4-C5 levels: a technical note

BACKGROUND CONTEXT

With the continuous development of the spinal endoscopic technique in recent years, percutaneous endoscopic cervical discectomy (PECD) has emerged, which bridges the gap between conservative therapy and traditional surgery and has been mainly divided into the anterior transdiscal approach and the posterior interlaminar access. Because of the relatively greater violation to the anterior nucleus pulposus, there is a higher potential of postoperative intervertebral space decrease in the anterior transdiscal approach than in the posterior interlaminar access. In addition, when the herniated lesion is migrated upward or downward behind the vertebral body, both approaches, and even anterior cervical discectomy and fusion, are impractical, and corpectomy is commonly considered as the only efficacious treatment. Anterior transcorporeal approach under endoscopy could enable an individual and adjustable trajectory within the vertebral body under different conditions of disc herniation preserving the motion of adjacent segment, especially in a migrated or sequestered lesion.

PURPOSE

This report aimed to first describe a novel anterior transcorporeal approach under endoscopy in which we addressed a migrated disc herniation at the C4-C5 levels.

STUDY DESIGN

A technical report was carried out.

PATIENT SAMPLE

A 37-year-old woman presented with posterior neck pain and weakness of extremities for 9 months. On neurologic examination, tingling sensation and numbness were not obvious. However, the power of extremities was dramatically decreased at a level of 3. Hoffmann sign was positive in the bilateral hand. Magnetic resonance imaging (MRI) showed a huge herniation of the C4-C5 disc compressing the median area of the spinal cord. Besides the C4-C5 disc herniation, preoperative computer tomography (CT) also detected that the herniated disc had partial calcification. A novel anterior transcorporeal approach of PECD, through the vertebral body of C5, was performed to address a migrated disc herniation at the C4-C5 levels.

OUTCOME MEASURES

The posterior neck pain was measured using the visual analog scale (VAS).

METHODS

A novel anterior transcorporeal approach under endoscopy was performed to address a migrated disc herniation at the C4-C5 levels.

RESULTS

This operation was accomplished in 75 minutes. Postoperatively, the drainage tube was retained into the drilling hole for 24 hours to avoid the possibility of hematoma. The patient was advised to wear a neck collar for 3 weeks. Immediately after the operation, the posterior neck pain improved from VAS 7/10 preoperatively to 3/10, and the myodynamia of extremities improved stepwise. At 12 hours postoperatively, the range of motion was also improved. In the further follow-up, the patient has completely recovered from the preoperative symptoms, whose myodynamia of extremities is normal. Besides the postoperative MRI, a total removal of the herniated disc and the transcorporeal drilling tunnel are observed in CT. At postoperative 3-month follow-up, neither disc space narrowing nor instability was observed on CT, in which the bone defect after drilling tunnelwas partially decreased, indicating bone healing. There were no surgery-related complications, such as dysphagia, Horner syndrome, recurrent laryngeal nerve palsy, vagus nerve injury, tracheoesophageal injury, or cervical hematocele.

CONCLUSIONS

As a supplement to the described surgical approach of PECD, the transcorporeal approach is a novel access for the treatment of cervical intervertebral disc herniation. Among the advantages of this approach are providing a clear visual field during microendoscopic surgery and decreasing the intraoperative iatrogenic injury to, as well as avoiding violation to the discal tissue. Theoretically, the potential of secondary decline of intervertebral height is low. However, as the limitation of one case shows, whether this transcorporeal approach is efficacious and reliable should be verified in a further comparative cohort study with a large volume of patients.

Sensorimotor C5 and C6 radiculopathy caused by thrombosed vertebral artery dissection and successfully treated with limited oblique corpectomy - Case report

The authors report the case of an exceptional presentation of vertebral artery dissection. A 44-year-old man who presented with left shoulder weakness, radicular pain and numbness of the left forearm and thumb was admitted to our hospital with an initial diagnosis of cervical disc herniation. Due to the inconsistency between the levels of radiculopathy (C5 and C6) and discopathy (C6-C7), neuroimaging examinations were extended. Based on MRI, MRA, CTA and DSA, left vertebral artery dissection with intramural hematoma was diagnosed. The patient underwent surgical decompression of the affected nerve roots using the anterolateral approach described by Bernard George. The radicular pain resolved immediately and sensorimotor deficit completely disappeared within 4 months. MRI/MRA performed 6 months after surgery showed the normal image of the vertebral artery. There were no ischemic events within 2.5 years of follow-up.

Multilevel oblique corpectomies as an effective surgical option to treat cervical chordoma in a young girl

Chordomas are malignant tumors arising from notochordal remnants. They are the most frequent tumors of the spine after plasmacytomas. Only 6% of chordomas are localized to the cervical level. In young patients, chordomas are rare and unpredictable. Despite this, the treatment of choice remains the total resection, as much as possible, followed by proton beam radiation. This case was managed using a precarotid and retrocarotid approach at the same time. The tumor was completely resected with the edges free from disease. The cervical spine was stabilized with an anterior plating C2-C4. Eighteen months after surgery the patient is still free from illness. Multilevel oblique corpectomies are an available and safe option for the treatment of upper cervical chordomas.

The V2 segment of the vertebral artery: anatomical considerations and surgical implications

Object

Iatrogenic injury of the V2 segment of the vertebral artery (VA) is a rare but serious complication and can be catastrophic. The purpose of this study was to characterize the relationship of the V2 segment of the VA to the surrounding anatomical structures and to highlight the potential site and mechanisms of injury that can occur during common neurosurgical procedures involving the subaxial cervical spine.

Methods

Ten adult cadaveric specimens (20 sides) were included in this study. Quantitative anatomical measurements between selected landmarks and the VA were obtained. In addition, lateral mass screws were placed bilaterally, from C-3 to C-7, reproducing either the Magerl technique or a modified technique. The safety angle, defined as the axial deviation from the screw trajectory needed to injure the VA, and the distance from the entry point to the VA were measured at each level for both techniques.

Results

The VA coursed closer to the midline at C3–4 and C4–5 (mean distance [SD] 14.9 ± 1.1 mm) than at C2–3 or C5–6. Within the intertransverse space it coursed closer to the uncinate processes of the vertebral bodies (1.8 ± 1.1 mm) than to the anterior tubercle of the transverse processes (3.4 ± 1.6 mm). The distance between the VA and the uncinate process was less at C3–6 (1.3 ± 0.7 mm) than at C2–3 (3.3 ± 0.8 mm). The VA coursed on average at a distance of 11.9 ± 1.7 mm from the anterior and 4.2 ± 2.6 mm from the posterior aspect of the intervertebral disc space. Lateral mass screw angles were 25° lateral and 39.1° cranial for the Magerl technique, and 36.6° lateral and 46.1° cranial for the modified technique. The safety angle was greater and screw length longer when using this modified technique.

Conclusions

The relation of the V2 segment of the VA to anterior procedures and lateral mass instrumentation at the subaxial cervical spine was reviewed in this study. A detailed anatomical knowledge of the V2 segment of the VA combined with careful preoperative imaging is mandatory for safe cervical spine surgery.

Oblique corpectomy to manage cervical myeloradiculopathy

Background. The authors describe a lateral approach to the cervical spine for the management of spondylotic myeloradiculopathy. The rationale for this approach and surgical technique are discussed, as well as the advantages, disadvantages, complications, and pitfalls based on the author's experience over the last two decades. Methods. Spondylotic myelo-radiculopathy may be treated via a lateral approach to the cervical spine when there is predominant anterior compression associated with either spine straightening or kyphosis, but without vertebral instability. Results. By using a lateral approach, the lateral aspect of the cervical spine and the vertebral artery are easily reached and visualized. Furthermore, the lateral part of the affected intervertebral disc(s), uncovertebral joint(s), vertebral body(ies), and posterior longitudinal ligament can be removed as needed to decompress nerve root(s) and/or the spinal cord. Conclusion. Multilevel cervical oblique corpectomy and/or lateral foraminotomy allow wide decompression of nervous structures, while maintaining optimal stability and physiological motion of the cervical spine.

ANTEROLATERAL APPROACH WITHOUT FIXATION FOR RESECTION OF AN INTRADURAL SCHWANNOMA OF THE CERVICAL SPINAL CANAL

OBJECTIVE

Although an anterolateral approach is an ideal approach to the anterior part of the cervical spinal canal, it is not often used because of various technical difficulties. This article presents the case of a patient with an intradural schwannoma ventrolateral to the spinal cord and describes the technique, anterolateral surgery without fixation, that was used to remove it.

CASE PRESENTATION

A 71-year-old man presented with neck pain and easy fatigability of the legs. Magnetic resonance imaging showed an intradural tumor ventrolateral to the spinal cord at the C3 level. The diagnosis was a schwannoma.

TECHNIQUE

A right anterolateral approach was selected for the resection. In the dissection between the sternocleidomastoid muscle and the internal jugular vein, the accessory nerve was retracted with the fat tissue. At C3, the prevertebral aponeurosis was laterally retracted to protect the sympathetic chain. The C3 transverse process was rongeured, and the vertebral artery was shifted laterally with the venous plexus. The C2–C3 uncovertebral joint and the right third of the C3 body were removed (partial corpectomy). The tumor was easily found in the dural sac and was totally removed. The surgical wound was closed in a watertight fashion. No fixation was necessary. The symptoms improved after the operation.

DISCUSSION

The anterolateral approach is one of the best approaches for resecting ventrally located intradural lesions because it allows minimally invasive surgery. Control and protection of the accessory nerve, sympathetic chain, and vertebral artery are the keys to success.

Extensive posterolateral exposure and total removal of the giant extraforaminal dumbbell tumors of cervical spine: surgical technique in a series of 16 patients

BACKGROUND CONTEXT

Removal of cervical dumbbell tumors can be particularly challenging because of unique exposure requirements and proximity of the vertebral artery (VA). There are no reports describing the treatment of giant cervical spine dumbbell tumors (CSDTs).

PURPOSE

To introduce an extensive posterolateral approach to CSDTs involving total lateral mass resection and laminectomy.

STUDY DESIGN

Prospective study of all the patients with multilevel CSDTs treated by this new procedure between December 2002 and March 2006.

PATIENT SAMPLE

Sixteen patients (3 men and 13 women) with CSDTs underwent the procedure we describe. The follow-up periods ranged from 9 to 51 months (average 9 months). Average age at surgery was 45 years (range 23-68 years).

OUTCOME MEASURES

Axial symptoms and Japanese Orthopedic Association scores were recorded. Pre- and postoperative ranges of neck motion were measured on lateral flexion and extension radiographs.

METHODS

After making a midline incision, we preferred exposing the extraforaminal component of the tumor before performing a semilaminectomy and lateral mass resection. Any lateral extension of a tumor can be attained by detachment of the adjacent three or more segments of the lateral mass muscle insertion. The most lateral portion can be separated beneath the tumor's superficial muscle flap, and then when the tumor is retracted medially, the whole portion of the lateral component can be totally exposed. We then performed total lateral mass resection and laminectomy to expose the tumor at the foramina and cervical canal.

RESULTS

We were able to completely resect the tumors in every patient. The average duration of surgery was 150 minutes. Blood loss was minimal (average 400 mL). All patients were monitored for a minimum of 9 months (range 9-51 months; mean 28 months). The follow-up period was uneventful, and no patients developed spinal instability.

CONCLUSIONS

Extensive posterolateral exposure enables surgeons to reach the lateralmost portion of CSDTs and also facilitates septation of the VA and resection of vertebral body encroachment of the tumor.

A combined posterior, lateral, and anterior approach to ventrolaterally situated chordoma of the upper cervical spine

BACKGROUND

Lesions ventral and ventrolateral to the neuraxis at the CCJ can pose a significant management problem owing to their strategic location. Conventional direct posterior approaches sometimes may not allow adequate visualization of the entire tumor base without significant manipulation of the brain stem and spinal cord. Here, we describe an approach that allows safe access to a ventrolaterally extending chordoma originating from the second and third cervical vertebrae.

CASE DESCRIPTION

A 31-year-old man was admitted to our institution with progressive motor weakness in his left arm and lower extremities and spastic gait disturbance. Neuroradiologic examination revealed an osseous tumor at the C2-3 level that presented with severe spinal cord compression and considerable bone destruction. We performed a resection of the tumor and posterior screw fixation from occiput to C5 using a conventional direct posterior approach. However, we were unable to reach a part of the tumor that extended far laterally to the left side with VA involvement. To expose and resect this remaining tumor, we used a far-lateral approach just posterior to the SCM muscle. Resecting the transverse processes of C2 and C3 and mobilizing the V2 segment of the VA adequately exposed the tumor for resection. After resection of the remaining posterior-lateral tumor, we closed and made the final approach anteriorly to resect the anterior tumor via an anterior corpectomy and fusion. No postoperative complications occurred, and the patient's neurologic status improved after surgery. He has had no craniocervical instability during the 2-year follow-up period.

CONCLUSION

When a direct posterior approach makes it difficult or impossible to reach tumors extending to the far lateral margins of the spine and soft tissues, the posterior-lateral approach described here allows excellent visualization and safe access with minimal neural retraction for treating these laterally situated lesions. We describe the surgical technique for a combined approach as an alternative to the direct posterior or anterior retropharyngeal approach.

Cervical spine lateral approach for myeloradiculopathy: technique and pitfalls

BACKGROUND

The authors describe the rationale of cervical spine lateral approach technique to manage spondylotic myeloradiculopathy with its advantages, disadvantages, complications, and pitfalls.

METHODS

The cervical lateral approach could be indicated to treat spondylotic myeloradiculopathy where anterior compression is predominant and the spine is straight or kyphotic without instability.

RESULTS

Using the present approach the lateral aspect of the cervical spine is easily reached and the vertebral artery is well controlled. The lateral part of the pathological intervertebral discs, uncovertebral joints, vertebral bodies and posterior longitudinal ligament are removed as necessary and decompression tailored to each patient to completely free the nerve roots and/or spinal cord.

CONCLUSION

The cervical lateral multilevel corpectomy/foraminotomy technique allows wide anterior decompression of the spinal cord and complete unilateral nerve root decompression preserving spinal stability and physiological spinal motion.

Multilevel oblique corpectomy without fusion in managing cervical myelopathy: long-term outcome and stability evaluation in 268 patients

Object

The multilevel oblique corpectomy (MOC) allows widening of the spinal canal and foramen trough via an anterolateral access to the cervical spine with control of the vertebral artery and does not require vertebral stabilization or fusion. In the present study, the authors' goal was to demonstrate the long-term efficacy and safety of MOC in the treatment of selected cases of spondylotic myelopathy.

Methods

The authors conducted a prospective study in a series of 268 patients who underwent MOC for cervical spondylotic myelopathy over a 14-year period. Preoperative and postoperative neurological functioning were evaluated with the modified Japanese Orthopaedic Association scale. Spinal stability was assessed in all patients on serial plain and dynamic cervical radiographs at the last follow-up. The degree of canal expansion after MOC was also measured using the spinal canal/vertebral body ratio, and directly by measuring the diameter of osseous canal on pre- and postoperative CT scans and high-resolution MR images.

Results

At a mean follow-up of 96 months, clinical improvement was recorded in 86.6% of patients with a global recovery rate of 87.6%, clinical stability in 8%, and worsening in 5%. Long-term spinal stability was demonstrated in 98% of patients.

Conclusions

Multilevel oblique corpectomy was demonstrated to be a safe procedure that provided good results in terms of improved functional status and long-term spinal stability.

Repair and regeneration of vertebral body after antero-lateral partial vertebrectomy using beta-tricalcium phosphate

Antero-lateral partial vertebrectomy (ALPV) was used for decompression in 91 patients with multilevel cervical disorders. The high-speed drill was used to excise about 1/3 of the vertebral body for relief of anterior compression of the cord and nerve roots under the operating microscope. The key point was opening of the medial wall of the foramen of transverse process at the beginning of the ALPV, allowing the determination of the lateral borders of the ALPVs. To repair and regenerate the vertebral body, a beta-tricalcium phosphate (beta-TCP) block was trimmed into a cuneiform shape and implanted into the sites of the ALPV excluding the upper and lowermost vertebral bodies. Postoperative computed tomography confirmed that beta-TCP was gradually replaced by newly formed bone from the surface towards the center of the block, and that the affected vertebral body was remodeled by 6 to 12 months after the implantation of beta-TCP. The cortical bone borders on the bone marrow at the site of the regeneration. The pedicles on the side of the ALPVs were rebuilt during regeneration of the affected vertebrae. Thus, the vertebral foramen of the cervical spine was widened in the anterior direction at the levels of the ALPVs, resulting in restoration of the physiological size of the cervical cord. The cervical curvature remained unchanged and a certain degree of cervical mobility (mean 86%) was preserved in this series.

Cervical spondylotic myelopathy treated by oblique corpectomy: a prospective study

OBJECTIVE

Anterolateral partial oblique corpectomy (OC) aims to decompress the cervical spinal cord without subsequent fusion and saves the patient from graft-, instrument-, and fusion-related complications. Although it is a promising technique, there are few studies dealing with its efficacy and safety.

METHODS

In this prospective study, 40 consecutive patients underwent an OC (one to four levels from C3 to C7) for cervical spondylotic myelopathy; they ranged in age from 43 to 78 years (mean, 55 yr). The average follow-up period was 59 months (range, 24-98 mo). Clinical and radiological data were analyzed to assess the results and find possible factors related to outcomes.

RESULTS

Thirty-seven (92.5%) of the 40 patients improved by the 6-month follow-up examination according to the Japanese Orthopedic Association score. The improvement was the most prominent in lower extremity dysfunction. Recovery was positively correlated with the preoperative Japanese Orthopedic Association score (r = 0.37, P = 0.018). Permanent Horner's syndrome developed in four patients (10%). During the long-term follow-up period, neurological improvement was maintained and there were no signs of postoperative instability, posture change, or axial pain.

CONCLUSION

OC for treating multilevel cervical spondylotic myelopathy achieved good results with a low morbidity rate. The results of the current study suggest that OC is a good alternative to conventional median corpectomy and fusion techniques in selected cases.

Prospective study of anterior cervical microforaminotomy for cervical radiculopathy

Cervical radiculopathy caused by a posterolateral disc herniation or spondylosis is a common pathology. Decompression of a stressed cervical nerve root is a routine neurosurgical procedure. To determine the safety and effectiveness of anterior cervical microforaminotomy (ACM), we prospectively studied patients undergoing this treatment at our institution to determine the efficacy of the approach for the treatment of unilateral cervical spondylotic or discogenic radiculopathy. Twenty-five patients were treated with ACM and were followed up for 15-40 months. Clinical signs, neurological results, and complications were recorded. Radiological imaging studies for measurement of post-operative changes were performed to evaluate spinal stability and effectiveness of the ACM procedure. We used MRI, axial cervical CT and reconstructive sagittal cervical CT to assess foraminal decompression. Eight men and 17 women (mean age 51.8 years) were included in this study. Nineteen patients had a single ACM, and six underwent procedures at adjacent 19 levels. The ACM procedure involves microsurgical removal of the lateral portion of the uncinate process to identify the nerve root. Post-operatively, none of the patients' conditions had worsened symptomatically or neurologically. A positive outcome at last follow-up examination was achieved in all patients. The visual analoge scale pain rating was 6.36 pretreatment and 0.64 after 1 year (p<0.0001). ACM appears to be a good alternative procedure, and a good non-fusion disc-preserving technique. Disc and bone resections are minimal in carefully selected patients with unilateral cervical radiculopathy. This method avoids osteoarthrodesis or arthroplasty with disc prostheses.

Anterolateral approach to the cervical spine: major anatomical structures and landmarks. Technical note

OBJECT

The authors undertook a study to explore the topographic anatomical features seen during the anterolateral approach to cervical spine, anatomical variations, and certain landmarks related to the surgical procedure.

METHODS

The study was conducted in 30 fresh cadavers.

RESULTS

The common carotid artery bifurcation was mostly found at the level of C-4 (78%). The inferior belly of the omohyoid muscle was seen to cross the sternocleidomastoid muscle at the C5-6 disc level along the entire C-6 vertebral body. To reach the lower cervical region, the sacrifice of this muscle makes the procedure easier. The facial vein drained into the internal jugular vein mostly at the level of C3-4 (54%). The superior ganglion of the cervical sympathetic chain was located at the C-4 vertebra, but the location of the intermediate ganglion exhibited some variation. The vertebral artery entered the transverse foramen of C-6 in 27 cadavers (90%), the transverse foramen of C-7 in two cadavers (7%), and the transverse foramen of C-4 in one cadaver (3%). Because the inferior thyroid artery crossed the C6-7 interspace obliquely, the course of the inferior thyroid artery may complicate the procedure. The C-5 uncinate process was shortest and narrowest and had the greatest distance from the medial edge of the process to the anterior tubercle (p < 0.001).

CONCLUSIONS

Understanding the qualitative anatomy of this region not only improves the safety of anterior and anterolateral cervical spine surgery but also allows adequate decompression of neural elements and resolution of the other pathological processes of this region. In this fresh cadaveric study, our goal was to improve the approach and decrease the incidence of complications.

Modified transcorporeal anterior cervical microforaminotomy for cervical radiculopathy: a technical note and early results

A prospective analysis of the first twenty patients operated for cervical radiculopathy by a new modification of transcorporeal anterior cervical foraminotomy technique. To evaluate early results of a functional disc surgery in which decompression for the cervical radiculopathy is done by drilling a hole in the upper vertebral body and most of the disc tissue is preserved. Earlier approaches to cervical disc surgery either advocated simple discectomy or discectomy with fusion, ultimately leading to loss of motion segment. Posterior foraminotomy does not address the more common anterior lesion. Twenty patients suffering from cervical radiculopathy not responding to conservative treatment were chosen for the new technique. Upper vertebral transcorporeal foraminotomy was performed with the modified technique in all the patients. All the patients experienced immediate/early relief of symptoms. No complications of vertebral artery injury, Horner's syndrome or recurrent laryngeal nerve palsy were noted. Modified transcorporeal anterior cervical microforaminotomy is an effective treatment for cervical radiculopathy. It avoids unnecessary violation of the disc space and much of the bony stabilizers of the cervical spine. Short-term results of this technique are quite encouraging. Longer-term analysis can help in outlining the true benefits of this technique.

Multilevel oblique corpectomy without fusion: our experience in 48 patients

STUDY DESIGN

The authors provide their results in performing multilevel oblique corpectomy for degenerative spondylotic myelopathy in 48 patients.

OBJECTIVE

To demonstrate the efficacy and safety of the multilevel oblique corpectomy when applied in selected cases.

SUMMARY OF BACKGROUND DATA

The technique of multilevel oblique corporectomies for treatment of cervical spondylogenetic myeloradiculopathies allows anterolateral access to the cervical spine so that the spinal canal and conjugate foramen can be widened at more than one level, without the need for vertebral stabilization.

METHODS

During a 7-year period, multilevel oblique corpectomy was performed in 48 consecutive patients for degenerative spondylotic myelopathy. The outcomes were analyzed according to the Japanese Orthopaedic Association classification modified to Western customs, and according to Nurick's scale 1 month, 1 year, and 2 years after surgery. Spinal stability was evaluated in all patients by plain radiograph films of the cervical spine, lateral views in flexion and extension, on discharge, 1 month and 1 year after operation.

RESULTS

Significant clinical improvement occurred in 29 patients with a complete functional recovery in 22; moderate improvement was achieved in 12 patients; neurological status remained stable in 5, and it worsened in 2. All patients showed spinal stability.

CONCLUSIONS

Multilevel oblique corpectomy was found to be a safe technique that guarantees good results in terms of both regression of clinical symptoms and long-term spinal stability.

Spinal extradural schwannoma

OBJECT

The authors endeavor to define the clinical and surgery-related profile of spinal nerve sheath tumors located in the extradural space outside both the dural sac and, apparently, the nerve roots' sleeve.

METHODS

A series of 24 extradural schwannomas was retrospectively selected after reviewing the notes of spinal nerve sheath tumors surgically treated at La Sapienza University of Rome. Clinical data, tumor-related characteristics, and outcome were analyzed. Women predominantly harbored these tumors. On admission sensory nerve root dysfunction was infrequently reported, whereas pyramidal tract deficits were often present. The tumor, generally large, was most frequently located in the intermediate thoracic segments and high cervical region; only one was reported in the lumbosacral region. Considerable erosion of vertebral bodies was reported in almost one third of the cases. In four patients eloquent nerve roots, that of C-5 in three and that of S-1 in one, were involved with the tumor. Radical tumor resection, with preservation of the nerve roots, was possible in several cases, whereas in two patients manipulation and resection of the C-5 root produced transient and permanent, respectively, root palsy. At follow-up examination patients for whom walking was impossible before surgery were now able to walk.

CONCLUSIONS

Extradural schwannomas can be distinguished from other nerve sheath tumors growing inside the spinal canal by their clinicoradiological features and unlikely nerve root origin. After surgery, recovery from pyramidal tract deficits, even severe, is noteworthy; in the authors' experience, however, resection of an involved appendicular root is more likely to result in a permanent and significant radicular deficit.

Clinical importance of ligamentous and osseous structures in the cervical uncovertebral foraminal region

The vertebral artery, cervical spinal nerves, spinal nerve roots, and the bony and ligamentous tissue related to the cervical vertebrae are structures whose anatomy determines the path of a surgical approach. Defining the anatomy and, in particular, determining the precise location of vulnerable structures at the intervertebral foramen and the uncovertebral foraminal region (UVFR), a region defined by the uncinate process anteriorly, the facet joint posteriorly and the foramen transversarium laterally, has critical significance when selecting the safest surgical approach. We studied the anatomy of the vertebral artery, cervical spinal nerves, and spinal nerve roots within the UVFR in six cadaver specimens. We also obtained measurements of bony structures in 35 dry cervical vertebral columns, from C3-C7. The uncinate process (UP) projects superiorly from the posterolateral aspect of each cervical vertebral body, except for the first and second vertebrae. Because the posterior part of the UP lies adjacent to the vertebral artery, spinal nerve, and spinal nerve roots, its resection creates sufficient space to decompress these structures directly. The posterolateral surface of the UP is covered by ligamentous tissue that originates from the posterior longitudinal ligament and protects the neural and vascular structures during their decompression in the UVFR.

Dumbbell C2 schwannomas involving both sensory and motor rootlets: report of two cases

OBJECTIVE AND IMPORTANCE

Intradural-extradural dumbbell C2 schwannomas are rare. This report concerns two such cases with the intradural compartment located ventral to the spinal cord and involving both sensory and motor rootlets.

CLINICAL PRESENTATION

One patient was a 57-year-old woman with sensory disturbances in the right extremities and hyperreflexia in the left extremities. The other patient was a 73-year-old man who presented with tetraparesis, walking disability, atrophy of the nuchal and bilateral shoulder muscles, and pain in the right C2 dermatome.

INTERVENTION

The extradural component of the tumor was removed first; next, the intradural component was removed successfully via the posterior approach combined with a C1-C2 laminectomy. The patients experienced symptomatic improvement without further deficits except for sensory impairment of the C2 dermatome in one of the patients.

CONCLUSION

Intradural-extradural dumbbell C2 schwannomas can be satisfactorily managed with a posterior approach. Removal of the extradural component and opening of the dural ring of the C2 nerve root are necessary for safe extraction of the intradural ventrally located component after debulking. These tumors may arise extradurally within the nerve sheath, extend intradurally and ventrally toward the spinal cord, and involve both sensory and motor rootlets.

Midline ventral intradural schwannoma of the cervical spinal cord resected via anterior corpectomy with reconstruction: technical case report and review of the literature

OBJECTIVE AND IMPORTANCE

Spinal cord schwannomas are intradural nerve sheath tumors that almost universally occupy a dorsolateral, lateral, or ventrolateral position. Therefore, resection of these lesions typically proceeds via a posterior or posterolateral approach.

CLINICAL PRESENTATION

We present a case of a midline ventral intradural schwannoma of the cervical spinal cord causing myelopathy. To the best of our knowledge, no previous reports specifically discuss purely midline ventral intradural schwannomas.

INTERVENTION

Resection of the tumor was performed via an anterior cervical corpectomy with spinal arthrodesis and fixation. We review possible causes for such an anomalous location for schwannoma as well as the advantages and disadvantages of various surgical strategies for removing the tumor.

CONCLUSION

This case exemplifies the usefulness of anterior approaches to the cervical spine in treating unusual intradural spinal cord tumors.

Lateral approach for resection of the C3 corpus: technical case report

OBJECTIVE AND IMPORTANCE

The C3 level is the transition zone between the upper and lower cervical spine. Because of its high position and anatomic relationships to significant structures, exposing C3 is challenging, and the surgical approach is controversial.

CLINICAL PRESENTATION

A 16-year-old girl was admitted to our institution with a 3-year history of neck pain and progressive quadriparesis. Neuroradiological examination revealed severe spinal cord compression from kyphosis at the C3 level.

TECHNIQUE

We used the lateral approach to resect the C3 corpus and realign the cervical spine. Resecting the transverse processes of C2-C4 and mobilizing the V2 segment of the vertebral artery adequately exposed C3 for resection. Bilateral occipitocervical fusion was performed in a second procedure, and no postoperative complications occurred. The patient's neurological status improved drastically after surgery, and she has had no craniocervical instability during the follow-up period.

CONCLUSION

The lateral approach to the C3 corpus offers the greatest degree of cord decompression and easy access to the lesion in a wide and sterile operative field. We describe the surgical technique of this approach as an alternative to the anterior transmucosal or anterolateral retropharyngeal approach.

The transverse process, intertransverse space, and vertebral artery in anterior approaches to the lower cervical spine

OBJECT

The microsurgical anatomy of the C3-6 transverse processes and their relationship to the intertransverse space and vertebral artery (VA) were examined with special attention to the aspect exposed in the anterior surgical approach.

METHODS

Ten adult cadaveric spines were examined (magnification levels X 3-40) after perfusion of the arteries and veins with colored silicone. The morphological detail of the transverse process and intertransverse space, the distances between selected surgical landmarks and the VA were measured, and the means and standard deviations were calculated. The osseous changes in the anterior root of the transverse process were classified according to their extent. The transverse processes became smaller, and the anterior intertransverse spaces and the width of the VA exposed in the space increased in size proceeding from caudal to rostral levels, thus exposing the VA to increased risk of injury during procedures at cephalad levels. The distance between the medial border of the longus colli muscle and the VA decreased when proceeding caudally from C2-3 to C4-5 interspaces but began to increase at the level of C5-6. The VA coursed closer to the lateral border of the vertebral body than to the medial border of the anterior tubercle of transverse process. Osseous changes consisting of thinning or defects in the anterior root of the transverse process were observed from C-3 to C-5. The thinning was most prominent in the lower half of the anterior root just above where the VA ascends behind the lower edge of the anterior root. The osseous change may reflect the erosive effect of the VA on the anterior root of the transverse process.

CONCLUSIONS

This study provides new information regarding the transverse process and especially the anterior root. An awareness of the thinness and defects in the anterior root of the transverse process and the relationships to the surrounding area will aid in reducing VA injury during anterior approaches to the cervical spine.

Vertebral autograft used as bone transplant for anterior cervical corpectomy: technical note

OBJECTIVE

In this prospective patient study, we used a surgical technique for autograft bone fusion during anterior cervical corpectomy (ACC) in patients experiencing cervical spondylotic myelopathy. We packed the resected bone material of the corpectomy into a titanium mesh cage. To evaluate the efficacy of our autograft technique, we analyzed the results according to neurological outcome, radiological outcome, and complications.

METHODS

Between 1995 and 1998, 27 ACC operations were performed for cervical spondylotic myelopathy caused by multisegmental cervical spondylosis. In all patients, decompression of the cervical canal and/or spinal nerve roots was performed by a median cervical corpectomy by an anterior approach. After the ACC was completed, a titanium mesh cage, which was variable in diameter and length, was filled with morselized and impacted bone material from the cervical corpectomy and was then implanted. An anterior cervical plate was placed in all patients to achieve primary stability of the cervical vertebral column. Age, sex, pre- and postoperative myelopathy, number of decompressed levels, radiological results, and complications were assessed. The severity of myelopathy was graded according to the scoring system of the Japanese Orthopaedic Association.

RESULTS

Symptomatic improvement of neurological deficits was achieved in 80% of the patients. The mean preoperative Japanese Orthopaedic Association score improved from 13.1 to 15.2 postoperatively (P < 0.05). No patient demonstrated worsening of myelopathic symptoms. Radiological follow-up studies demonstrated complete bony fusion in all patients. A vertical movement of 2.25 +/- 0.43 mm of the titanium cage into the adjacent vertebral bodies was observed in 24 patients. In patients with either a lordotic or neutral cervical spinal axis postoperatively, the axis remained unchanged during the entire follow-up period.

CONCLUSION

The results of this study demonstrate that transplantation of autograft bone material harvested during the ACC integrated well in the cage and in the adjacent vertebral bodies. Thus, complications associated with explantation of autograft material from other donor sites, e.g., the iliac crest, could be avoided. The early postoperative and midterm follow-up periods provided no evidence of morphological or functional instability of the operated cervical segments when this autograft technique was used in combination with cervical instrumentation.