Transuncodiscal approach to dumbbell tumors of the cervical spinal canal

A Novel and Reproducible Classification of Cervical Dumbbell Tumors to Inform Surgical Approach and Reconstruction Techniques

STUDY DESIGN

A retrospective case series.

OBJECTIVE

This study developed a novel classification system based on imaging and anatomy to select optimal surgical approaches and reconstruction strategies to achieve total resection of cervical dumbbell tumors and restore spinal stability.

SUMMARY OF BACKGROUND DATA

Total resection is necessary to decrease the recurrence rate of cervical dumbbell tumors. Previous cervical dumbbell tumor classifications are insufficient for determining surgical strategies; therefore, a practical classification is needed.

MATERIALS AND METHODS

This study included 295 consecutive patients with cervical dumbbell tumors who underwent total surgical resection. A novel classification of cervical dumbbell tumors was developed based on magnetic resonance imaging and computed tomography. Continuous variables were expressed as mean±SD and were compared using an unpaired two-tailed Student t test. The χ 2 test or the Fisher exact test was used for categorical variables. Kendall's W test assessed three independent raters' inter-rater and intrarater reliabilities on 140 cervical dumbbell tumors.

RESULTS

The inter-rater and intrarater consistency coefficient was 0.969 (χ 2 =404.3, P <0.001) and 0.984 (χ 2 =273.7, P <0.001). All patients with type I and II tumors underwent single-posterior surgeries to achieve total resection. Of the patients in this study, 86.1%, 25.9%, 75.9%, and 76.9% underwent posterior surgeries for types IIIa, IIIb, IVa, and V tumors, respectively. All patients with type IVb tumors underwent a combined anterior and posterior approach. Posterior internal fixation was used for all patients in posterior surgery. Anterior reconstruction was applied for patients with type IVb tumors (20/20, 100%) and some with type V tumors (3/13, 23.1%). The mean follow-up duration was 93.6±2.6 months. A recurrence was observed in 19 (6.4%) patients.

CONCLUSION

The authors describe a novel classification system that is of practical use for planning the complete resection of cervical dumbbell tumors.

Vertebral artery is an anatomical landmark in the posterior unilateral resection of cervical benign nerve sheath tumors with dumbbell extension of Eden type 2 or 3

Background

In the cervical nerve sheath tumor (NST) surgery with dumbbell extension of Eden type 2 or 3, selection of anterior, posterior, or combined approach remains controversial.

Objectives

This technical note aimed to propose possible advantages of the posterior unilateral approach (PUA). Methods: Six patients who underwent the surgical treatment of cervical NSTs with dumbbell extension of Eden type 2 or 3 were included. The critical surgical steps included (1) complete separation of extradural and intradural procedures, (2) careful peeling of the neural membranes (epineurium and perineurium) from the tumor surface in the extradural procedure, (3) complete removal of the extradural tumor within the neural membranes, (4) intradural disconnection of tumor origin, and (5) intentional tumor removal up to the vertebral artery (VA), i.e., the VA line.

Results

The tumor location of dumbbell extension was Eden types 2 and 3 in two and four patients. Gross total resection was achieved in two patients and intentional posterior removal of the tumor to the VA line was achieved in the remaining four patients. No vascular or neural injuries associated with surgical procedures occurred. Postoperative neurological assessment revealed no symptomatic aggravation in all patients. No secondary surgery was performed during the study period.

Conclusion

PUA was safe and less invasive for functional recovery and tumor resection, if the anatomical relationship between the tumor and VA is clearly understood. The VA line is an important anatomical landmark to limit the extent of tumor resection.

Benign Peripheral Non-cranial Nerve Sheath Tumors of the Neck

Benign peripheral non-cranial nerve sheath tumors are rare lesions, including both schwannomas and neurofibromas. These tumors arise from Schwann cells, and may originate from any peripheral, cranial, or autonomic nerve. Most of them are localized and sporadic but multifocal systemic forms can occur. Cervical sympathetic chain, brachial plexus, cervical plexus and spinal roots and nerves are the major nerve systems commonly affected. Dumbbell-shaped intra- and extradural tumors occur most commonly in the cervical spine, as well as purely extradural and paravertebral tumors. The management of these tumors has improved greatly owing to the developments in imaging techniques and surgical innovations such as endoscopically assisted approaches and robotic surgery. Microsurgical intracapsular excision of the tumor helped by the use of intraoperative fluorescent dyes and intraoperative neurophysiological monitoring minimize postoperative neural deficit, since most schwannomas are encapsulated. Most tumors can be removed with a low rate of complications and recurrence. Radiotherapy should be considered for growing lesions that are not amenable to surgery. In asymptomatic patients, observation and serial scans is an option for elderly infirm patients.

Dumbbell-shaped meningioma of Meckel's cave mimicking trigeminal schwannoma: A case report

INTRODUCTION AND IMPORTANCE

Several meningioma cases arising through Meckel's cave (MC) at the middle and posterior fossa have been reported. However, few relevant meningiomas have been observed with a dumbbell shape.

PRESENTATION OF CASE

We report a rare case of a 36-year-old woman with a meningioma of MC with a typical dumbbell-shaped, schwannoma-like presentation on magnetic resonance imaging (MRI), resulting in a misleading differential diagnosis.

CLINICAL DISCUSSION

In this case report, we discuss the characteristics of meningioma of MC observed on MRI and our surgical approach to this condition.

CONCLUSION

This tumor was able to mimic a trigeminal schwannoma both clinically and radiographically. This case report has been reported in line with the SCARE 2020 criteria [1].

Lateral Transtumoral Transforaminal Removal of Cervical Dumbbell Tumors

Background Cervical dumbbell tumors constitute 15% of cervical nerve sheath tumors. These tumors occupy intraspinal, foraminal, and extraspinal compartments. Laminectomy, laminectomy and facetectomy and anterolateral partial vertebrectomy are the approaches used to address these multicompartment tumors. Laminectomy leads to incomplete tumor removal. Other approaches ensure complete tumor excision but involve more extensive bone work.

Objective We describe our surgical technique and clinical experiences of six patients treated through single lateral approach, addressing all compartments (transforaminal approach) with minimal or no bony resection.

Methods Six patients with cervical dumbbell tumors underwent minimally invasive transforaminal approach and tumor excision. The cohort consisted of four women and two men. All patients underwent complete tumor excision

Technique Intraoperative X-ray and ultrasound are used to localize the respective foramen. Skin is entered from the lateral side and sequential dilatation is done through muscles. The dilators and port are docked to the lateral surface of articular facets. Standard technique of capsule dissection, internal decompression and capsule mobilization is done to remove the tumor. Arachnoid is seen at the end. Tumor cavity is obliterated with fat graft.

Results Total excision of tumor was documented in all patients with postoperative MRI scan. The mean blood loss was 100 mL. The patients could be discharged on second or third postoperative day. Mean follow-up is of 48 months (18–70 months) and all patients had resolution in features of myelopathy.

Conclusions Endoportal transforaminal approach is technically feasible and minimally invasive option to remove the dumbbell schwannomas.

Revisiting the surgical corridors for cervical Type IIb-c dumbbell neurofibroma: A series of two unconventional approaches and review of literature

Background:

Cervical sub-axial dumbbell neurofibromas (NFs) account for nearly 20% of all NFs, with prognosis depending on the extent of excision. When majority of tumor is extra-foraminal (Tomaya's Type IIb and c), certain unconventional anterolateral or posterolateral neck approaches are used for maximum safe excision. In our article, we provide a brief review of the literature regarding various surgical approaches, emphasizing the utility of posterolateral or combined anterior and posterior neck approaches for such giant NF.

Methods:

We performed a retrospective analysis of prospectively maintained surgical databases, from our hospital discharge codes, for all cervical Type IIb-c dumbbell NF patients, who underwent surgery at our institution between 2015 and 2019. Clinical variables included age at admission, clinical presentation, and surgical difficulties, and the outcome was analyzed.

Results:

Four patients of age ranging from 22 to 45 years (M:F 3:1) were operated by posterolateral (n = 3) and combined anteroposterior (n = 1) approach. Three patients underwent near-total excision and one patient had total excision. One patient with tumor capsule attached to roots of upper brachial plexus had motor deficit, who was re-admitted for neurotization. There was no intraoperative complication.

Conclusion:

Posterolateral approach for cervical dumbbell giant NFs is safe, effective, and promises maximum safe excision. The major blood vessels including carotid artery or jugular veins in neck and vertebral artery at foraminal portion are directly under vision and control of surgeon. Despite near-total excision, wherein small part of adhered capsule is left, recurrence rate is low.

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.

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.

SPINAL DUMBBELL EPIDURAL HEMANGIOMA: TWO STAGE/SAME SITTING/SAME POSITION POSTERIOR MICROSURGICAL AND TRANSTHORACIC ENDOSCOPIC RESECTION - CASE REPORT AND REVIEW OF THE LITERATURE

SUMMARY – Spinal dumbbell tumors are defined by a narrowing at the point where they penetrate the intervertebral foramina or dura mater, assuming an hourglass or dumbbell shape. Dumbbell-shaped spinal hemangiomas are extremely rare. We describe a dumbbell spinal tumor (epidural cavernous hemangioma) resected by a 2-stage single-sitting combined approach. We also conduct a substantial literature review of the subject. We present a case of a 78-year-old male who was found to have a homogeneously enhancing, dumbbell-shaped, intraspinal, extradural tumor mass extending into the left chest cavity. The tumor was resected with a single-sitting 2-stage posterior technique: a microsurgical approach, followed by endoscopic resection via a thoracoscopic approach. There are several reports in the literature on the combined approach for dumbbell tumors of the spinal cord. Our case is the first to describe 2-stage combined surgery in 1 sitting for dumbbell hemangioma with the patient in the lateral decubitus position for the thoracoscopic part of the surgery; and the use of a fat pad, which was applied in the neuroforamen via the posterior route, as a marker for resection during the transthoracic procedure.

The subatlantic triangle: gateway to early localization of the atlantoaxial vertebral artery

OBJECTIVE Exposure of the vertebral artery (VA) between C-1 and C-2 vertebrae (atlantoaxial VA) may be necessary in a variety of pathologies of the craniovertebral junction. Current methods to expose this segment of the VA entail sharp dissection of muscles close to the internal jugular vein and the spinal accessory nerve. The present study assesses the technique of exposing the atlantoaxial VA through a newly defined muscular triangle at the craniovertebral junction. METHODS Five cadaveric heads were prepared for surgical simulation in prone position, turned 30°-45° toward the side of exposure. The atlantoaxial VA was exposed through the subatlantic triangle after reflecting the sternocleidomastoid and splenius capitis muscles inferiorly. The subatlantic triangle was formed by 3 groups of muscles: 1) the levator scapulae and splenius cervicis muscles inferiorly and laterally, 2) the longissimus capitis muscle inferiorly and medially, and 3) the inferior oblique capitis superiorly. The lengths of the VA exposed through the triangle before and after unroofing the C-2 transverse foramen were measured. RESULTS The subatlantic triangle consistently provided access to the whole length of atlantoaxial VA. The average length of the VA exposed via the subatlantic triangle was 19.5 mm. This average increased to 31.5 mm after the VA was released at the C-2 transverse foramen. CONCLUSIONS The subatlantic triangle provides a simple and straightforward pathway to expose the atlantoaxial VA. The proposed method may be useful during posterior approaches to the craniovertebral junction should early exposure and control of the atlantoaxial VA become necessary.

Solitary Osteochondroma Presenting as a Dumbbell Tumor Compressing the Cervical Spinal Cord

We report a case of a solitary osteochondroma as a dumbbell tumor compressing the spinal cord and its surgical strategy. The patient is a 16-year-old female with longstanding posterior neck pain and left arm abduction weakness. She was examined by plain X-ray, three-dimensional-computed tomography, magnetic resonance imaging, and vertebral angiography. The analyses indicated a calcified extradural mass compressing the cord in the C3–4 portion extending into the neural and vertebral foramen with eroded vertebral body. The tumor was successfully excised using a modified combined anterior and posterior approach. Histopathologic study of the resected material confirmed the diagnosis. The postoperative assessment was followed by clinical and radiologically therapy for 5 years after surgery. Osteochondroma arises from enchondral bone but it rarely involves the spine, especially not as s dumbbell type. In this patient, the tumor may have arisen from the neural arch and extended into the extradural and extraforaminal space over a long period. We successfully removed the dumbbell tumor with a combined anterior oblique and posterior approach. However, further observation is essential because of the possibility of recurrence and sarcomatous change.

Posterior Paramedian Approach to Ventrally Located Spinal Meningioma

BACKGROUND

To approach a ventral spinal pathology, a lateral viewing angle is often required. However, lateral approaches to the spine are usually more technically demanding and require a certain amount of surgical expertise. In this report, we describe a simple and easy technique to obtain the lateral viewing angle to the ventral spinal pathology.

CASE DESCRIPTION

The technique is demonstrated in a ventrally located meningioma at the C2 level. Axial magnetic resonance imaging showed a square posterior shift of the spinal cord with little lateral space, which necessitated a more lateral viewing angle than the conventional posterior approach. With the patient in a prone position, we made a horizontal skin incision at the level of C2 and unilaterally exposed the right side of the C1 and C2 laminae. We then made a small perpendicular incision on the medial portion of the paravertebral muscles, which we retracted longitudinally. This approach provided an unobstructed lateral view toward the spinal cord. Following a gross total removal of the tumor with minimal cord retraction, the patient made an uneventful recovery. Her preoperative neurologic symptoms completely resolved in 2 months. No significant muscle atrophy was observed on postoperative magnetic resonance imaging at 3 months. There was no long-term complication related to the muscle incision at 1-year follow-up.

CONCLUSION

The posterior paramedian approach is a simple and versatile technique to obtain lateral viewing angle to the spine and useful for approaching lesions residing ventral to the spinal cord.

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.

Single stage transforaminal retrojugular tumor resection: The spinal keyhole for dumbbell tumors in the cervical spine

BACKGROUND

Dumbbell tumors are defined as having an intradural and extradural component with an intermediate component within an expanded neural foramen. Complete resection of these lesions in the subaxial cervical spine is a challenge, and it has been achieved through a combined posterior/anterior or anterolateral approach. This study describes a single stage transforaminal retrojugular (TFR) approach for dumbbell tumors resection in the cervical spine.

METHODS

This is a retrospective review of a series of 17 patients treated for cervical benign tumors, 4 of which were "true" cervical dumbbell tumors operated by a simplified retrojugular approach. The TFR approach allows a single stage gross total resection of both the extraspinal and intraspinal/intradural components of the tumor, taking advantage of the expanded neural foramen. All patients were followed clinically and radiologically with magnetic resonance imaging (MRI).

RESULTS

Gross total resection was confirmed in all four patients by postoperative MRI. Minimal to no bone resection was performed. No fusion procedure was performed and no delayed instability was seen. At follow up, one patient had a persistent mild hand weakness and Horners syndrome following resection of a hemangioblastoma of the C8 nerve root. The other three patients were neurologically normal.

CONCLUSIONS

The TFR approach appears to be a feasible surgical option for single stage resection in selective cases of dumbbell tumors of the cervical spine.

Unilateral extended suboccipital approach for a C1 dumbbell schwanoma

Craniovertebral junction tumors represent a complex pathology carrying a high risk of injuring the vertebral artery and the lower cranial nerves. Dumbbell C1- C2 schannomas are very rare tumors in this location. We present a case of a 66 years old male accepted for left laterocervical localized pain, headache and vertigo, with a large C1 dumbbell schwannoma extending in lateral over the C1 arch and displacing the C3 segment of the vertebral artery superiorly and anteriorly. Complete removal of the tumor was achieved using a far lateral approach. The approach is discussed with focus on the vertebral artery anatomy as the approach should give enough space to gain control of the artery without creating instability. Safe removal of C1 nerve root schwanomas can be achieved even if they compress and displace the vertebral artery by entering a fibrous tissue plane between the tumor and the vertebral artery.

Surgical management of solitary nerve sheath tumors of the cervical spine: a retrospective case analysis based on tumor location and extension

Complete resection of spinal nerve sheath tumors (NSTs) does not always result in significant neurological deficit. The purpose of this retrospective case analysis was to discuss the optimal surgical strategy for spinal NST of the cervical spine. Twenty-four patients who underwent surgery for solitary cervical NST over the past decade were included in this retrospective study. Patients with neurofibromatosis or schwannomatosis were excluded. Seventeen of the 24 cases (70.8%) showed extradural dumbbell extension, most frequently at the C1 or C2 vertebral level. Neurological condition was assessed using the modified McCormick functional schema and sensory pain scale. Total removal of the tumor was achieved in 20 of 24 cases (83.3%). Staged surgery using combined anterior and posterior approaches was applied for 2 of 17 cases with extradural dumbbell extension. Tumor involvement with nerve root fibers critical for upper extremity function (C5–C8) was recognized in 6 of 24 cases (25.0%), with complete resection in all 6 cases. Final assessment of neurological function revealed satisfactory or acceptable recovery in all 6 patients. Spinal NSTs with extradural dumbbell extension are a common condition in the cervical spine. Complete removal of spinal NST of the cervical spine may carry a risk of permanent neurological deficit, but such sequelae appeared to be the exception in the present case analysis. A radical and safe surgical strategy, including staged surgery combining anterior and posterior approaches, should be tailored to the individual case.

A dumbbell-shaped meningioma mimicking a schwannoma in the thoracic spine

A 50-year-old man presented bilateral hypesthesia on and below the T6 dermatome and paresthesia. Magnetic resonance imaging (MRI) showed an intraspinal extradural tumor, which located from the 6th thoracic vertebral body to the upper margin of the 7th vertebral body, continuing dumbbell-like through the intervertebral foramen into the right middle thorax suggesting a neurogenic tumor (neurofibroma or neurilemmoma). With the patient in a prone position, we exposed and excised the tumor via a one stage posterior approach through a hemi-laminictomy of T6. Histologic examination showed a grade 1 meningothelial meningioma, according to the World Health Organization classification. Initially, we assumed the mass was a schwannoma because of its location and dumbbell shape. However, the tumor was actually a meningioma. Postoperatively, hypesthesia resolved completely and motor power of the leg gradually full recovered. A postoperative MRI revealed no evidence of residual tumor.

Concurrent spinal nerve root schwannoma and meningioma mimicking single-component schwannoma

We present a first case of concurrent tumors consisting of schwannoma and meningioma arising at the same spinal level in a patient without neurofibromatosis. A 49-year-old man without clinical evidence of neurofibromatosis presented with a 5-month history of right neck pain. MRI demonstrated an extradural tumor involving the right-sided C2 nerve root with a small intradural component. T1- and T2-weighted and contrast-enhanced MRI could not differentiate the intradural tumor as different from the extradural tumor. Total removal of the tumors was performed. No contiguity of the extradural tumor with the intradural tumor was seen. The intradural tumor attached strongly to the dura mater around the C2 nerve root exits. Intraoperative pathological diagnosis confirmed the extradural tumor as schwannoma and the intradural tumor as meningioma. We therefore thoroughly coagulated the dura mater adjacent to the intradural tumor and resected the dura mater around the nerve root exits together with the tumor. Pathological examination revealed that the resection edge of the extradural component consisted of a spinal nerve with thickened epineurium and was free of neoplastic cells. No schwannoma component was evident in the intradural tumor. No obvious transition thus existed between the extra- and intradural tumors. Distinguishing these tumors prior to surgery is critical for determining an optimal surgical plan, as schwannoma and meningioma require different surgical procedures. We therefore recommend a careful review of preoperative imaging with the possibility of concurrent tumors in mind.

Surgery of spinal nerve sheath tumors originating from C1 or C2 of high cervical spine

Spinal nerve sheath tumors (NSTs) originating from the C1 or C2 level are unique from both anatomical and clinical perspectives. Surgical technique to accomplish radical but safe resection of these tumors is described in 8 cases treated during the past 5 years. Surgical measures included positioning the patient in the lateral oblique position, unilateral posterior approach, exposure of the tumor along the surgical plane of the dural or perineural boundary, and proximal and distal amputation of the tumor with resection of dural penetration. Excessive bone resection and soft tissue manipulation were unnecessary. Microscopic complete removal of the tumor was accomplished in seven of eight cases. Subtotal resection was done in one case where the tumor extended beyond the vertebral artery. Functional assessment demonstrated satisfactory improvement after surgery in all cases. Surgery-related complications were not encountered in any case. Exposure of the tumor along the surgical plane of the dural or perineural boundary may be the key procedure required to accomplish radical but safe resection of spinal NSTs originating from the C1 or C2 level.

Abordagem cirúrgica posterior e posterolateral para neurinomas cervicais em ampulheta da raiz de C2

OBJETIVO: os autores relatam a experiência cirúrgica de 11 neurinomas em ampulheta de C2 comparando à via de acesso posterior com a posterolateral. MÉTODOS: onze pacientes com neurinomas em ampulheta de raiz cervical de C2 foram tratados cirurgicamente. A via de acesso utilizada para a remoção dos tumores foi a abordagem posterior em sete pacientes, e a posterolateral em quatro pacientes. RESULTADOS: houve predominância do sexo feminino (n=6) e a média de idade foi de 55,9±8,16 anos. O tempo médio de sintoma até o diagnóstico foi de 16,3 meses (±8,02 meses). Houve ressecção completa do tumor em todos os pacientes. O tempo cirúrgico médio na abordagem posterior foi de 180 minutos (±39,15) e de 192 minutos (±22,17) pela via posterolateral (p=0,52). Não houve diferença estatisticamente significativa entre as abordagens em relação ao sangramento transoperatório (posterior: 70,71±16,93; posterolateral: 65,00±24,15; p=0,64). Ocorreu uma complicação com a via de acesso posterior ligada à presença de uma fístula de líquor, sendo necessária nova intervenção e reconstrução da dura-máter utilizando a fáscia lata. CONCLUSÃO: a retirada completa do tumor em ampulheta da raiz de C2 é possível através das abordagens posterior e posterolateral, entretanto, a abordagem posterior é preferível por ser a via de acesso mais familiar ao cirurgião.

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.

Anterior approach to cervical intramedullary pilocytic astrocytoma

Although there has been considerable experience with anterior approaches to ventral intradural, extramedullary, and pial-based spinal lesions, there is no information in the literature regarding the safety and feasibility of the resection of an intramedullary tumor via an anterior approach. The authors report on the gross-total resection of an intramedullary cervical pilocytic astrocytoma via a C-7 corpectomy and anterior myelotomy. The surgery proceeded without complication, and postoperatively the patient maintained the preoperative deficit of mild unilateral hand weakness but had no sensory deficits. Follow-up MR imaging at 6 months showed gross-total macroscopic resection. Selected intramedullary tumors can be safely removed via an anterior approach. This approach avoids the typical sensory dysfunction associated with posterior midline myelotomy.

Anterior corpectomy approach for removal of a cervical intradural schwannoma

Spinal schwannomas are typically intradural-extramedullary neoplasms thought to arise from Schwann cells or their progenitors which occur proportionally throughout the spinal canal. They most typically arise from dorsal sensory rootlets and occupy a posterior-lateral location in the spinal canal. Thus, posterior surgical procedures have become the conventional method to remove these tumors providing adequate exposure in most cases. More anteriorly located tumors may be approached through a posterolateral direction with section of the dentate ligament and gentle rotation of the spinal cord. However, posterior and posterolateral approaches may be problematic for removing tumors located in the midline and ventral to the spinal cord.

Although the anterior approach has been applied widely to treat cervical spondylosis, it has rarely been used to remove intradural tumors. Here, we present a case of a ventral cervical spinal schwannoma removed through an anterior approach followed by spinal reconstruction.

Cervical Hemilaminoplasty: Technical Note

Ten patients with cervical spinal schwannomas were operated using a new posterior approach, termed cervical hemilaminoplasty. A thread wire saw (T-saw) was used to cut the lamina at the center of the spinous process and at the unilateral pars interarticularis on the affected side. The unilateral lamina, the inferior articular process, and half of the spinous process were resected as a single mass. After tumor excision, the resected lamina was restored to the original site and fixed. Fusion technique was not required. The mean number of resected and restored lamina was 1.5. No instability of the cervical spine was detected using flexion/extension x-ray photography. Although worsening of radicular motor function was observed in 2 cases, the weakness was not permanent and both cases showed full recovery. Postoperative magnetic resonance imaging was performed in 7 of the 10 cases and showed no recurrences. Cervical hemilaminoplasty is a useful posterior approach method for spinal tumors and especially dumbbell-type tumors. This method provides wide exposure of the foramen and of the inside of the canal. Furthermore, it allows reconstruction of the posterior element of the spinal canal and results in good stability.

Complete removal of an intraspinal and extraspinal cervical chordoma in one stage using the lateral approach. Technical note

The authors describe a precise surgical technique in which a large intraspinal and extraspinal, multivertebral, cervical chordoma was completely removed in one stage using the lateral approach. The patient in this case was a 29-year-old woman who presented with signs of radicular pain in the left C-3 area. Computed tomography and magnetic resonance imaging demonstrated a large intra- and extraspinal multivertebral tumor from C-2 to C-5, a finding that suggested a cervical chordoma. The tumor was completely removed in one stage using the lateral approach while controlling the vertebral artery (VA), and a partial corporectomy of C2-5 was also performed. Results from a postoperative histopathological examination confirmed that the tumor was a typical chordoma. The patient's postoperative course was uneventful. Cervical chordomas are typically excised using a posterior-anterior surgical approach with partial resection of the tumor. The lateral approach was appropriate in this patient for complete resection in one stage, because it enabled the surgeons to control the VA and access both extraspinal and intraspinal components of the chordoma.

Hémangioblastome « en sablier » de la huitième racine cervicale

Hemangioblastomas involving cervical nerve roots are extremely rare. Only one case has been previously reported in the literature. We report the case of a 33-year-old man presenting with a 6-month history of upper limb pain. MRI and cervical angiography demonstrated the presence of a dumbell (intra and extradural) and highly vascularized tumor of the right C7-T1 foramina. Histological examination eventually confirmed the diagnosis of hemangioblastoma. Total removal of such a lesion may require combined (anterior and posterior) approaches and preoperative embolization.

The Anterolateral Partial Vertebrectomy Approach for Ventrally Located Cervical Intramedullary Cavernous Angiomas

OBJECTIVE:

We report three cases with ventral cervical intramedullary cavernous angiomas. An anterolateral partial vertebrectomy was performed to surgically approach and successfully resect these lesions.

MATERIALS AND METHODS:

All three patients presented with numbness in the upper extremities and investigation revealed a cavernous angioma on the ventral aspect of the spinal cord in each case. The lesion was exposed by an anterolateral partial vertebrectomy in all cases. Postoperative stabilization was achieved by using autografted iliac bone in all patients. In two patients, locking screws and plates were also used.

RESULTS:

Complete resection of the cavernous angioma was performed in all patients. There was symptomatic relief in all cases, and there was no postoperative morbidity.

CONCLUSION:

Anterolateral partial vertebrectomy provides direct exposure and is probably an ideal approach for selected cases with ventrally located intramedullary cavernous angiomas.

Artificial pedicle screw reconstruction of the cervical spine after lateral paramedian transpedicular approach for lesions of the ventral cervical spinal canal

OBJECTIVE

We describe in detail the anatomic and surgical principles of a lateral cervical paramedian transpedicular approach, a novel technique that provides access to the ventral cervical spinal canal. We also describe single-stage posterior column reconstruction of the cervical spine in which traditional cervical lateral mass screws are used simultaneously to reconstruct the cervical pedicle and to allow for three-column stabilization in a continuous posterior screw-rod construct after this approach.

METHODS

This technique is a modification of traditional thoracic posterolateral extracavitary approaches and has been used by our group for the resection of intradural and extradural spinal lesions, as we illustrate.

RESULTS

This approach is particularly useful in cases where significant pathological characteristics of the trachea or esophagus preclude an anterior approach to the cervical spine and in cases in which multiple levels are involved.

CONCLUSION

Cervical spinal stability is enhanced, because all cervical levels are incorporated into the final screw-rod construct.

Cervical dumbbell meningioma and thoracic dumbbell schwannoma in a patient with neurofibromatosis

The occurrence of both dumbbell meningioma and dumbbell schwannoma in one patient has not been reported in the literature. We present a 16-year-old female patient, who had progressive bilateral hearing impairment for 5 years and a progressively enlarged, non-tender neck mass for 1.5 years. Mild motor weakness over her right upper limb was noted 1 week before admission. No café-au-lait spot was noted. Magnetic resonance imaging (MRI) revealed bilateral cerebellopontine angle tumors, a C1-2 dumbbell tumor, and a T5-6 dumbbell tumor. Neurofibromatosis type 2 was diagnosed. The cervical spine and thoracic spine tumors were removed via one-staged combined posterior (laminectomy) and antero-lateral (transforaminal or thoracoscopic) approaches during two operations performed 1 month apart. The pathology revealed meningioma and schwannoma, respectively. The patient had good recovery after these two operations and her motor function improved. Six months after the second surgery, radiosurgery was performed for the bilateral acoustic tumors, because of enlarged tumor size on follow-up MRI. To the best of our knowledge, this is the first case reported in the literature of a patient, having both dumbbell meningioma and dumbbell schwannoma. A literature review of the dumbbell tumors was done, and their treatment strategies were discussed.

Cervical Dumbbell Intra-extradural Hemangioblastoma: Total Removal through the Lateral Approach: Technical Case Report

OBJECTIVE AND IMPORTANCE:

Extradural hemangioblastomas account for 8 to 12% of all spinal hemangioblastomas. Among them, intra-extradural forms with a dumbbell extension are extremely rare. We report a case of intra-extradural hemangioblastoma involving the C6 cervical nerve root.

CLINICAL PRESENTATION:

The patient was a 31-year-old woman presenting with signs of myelopathy and C6 radiculopathy on the right side. A computed tomographic scan and magnetic resonance imaging demonstrated a dumbbell tumor that had developed through the C5–C6 intervertebral foramen. Angiography revealed a well-circumscribed mass with feeders from the vertebral artery and the deep cervical artery.

INTERVENTION:

The tumor was totally removed through the lateral approach, with control of the vertebral artery and sacrifice of the C6 cervical nerve root. Limited bone drilling to enlarge the foramen permitted us to reach and resect the intradural component. Histopathological examination confirmed the diagnosis of hemangioblastoma. Follow-up was uneventful.

CONCLUSION:

This is the sixth reported case of a cervical dumbbell hemangioblastoma investigated by computed tomographic scanning and MRI but the first one resected via the lateral approach. The lateral approach seems appropriate for surgical resection because it provides primary control of the vascular feeders and access to the extradural and intradural components.

Surgical strategy for cervical dumbbell tumors based on a three-dimensional classification

STUDY DESIGN

Forty-two patients with cervical dumbbell tumors were analyzed retrospectively using a new three-dimensional classification.

OBJECTIVES

To establish optimal surgical strategies, we considered shapes and three-dimensional locations of cervical dumbbell tumors based on diagnostic images and intraoperative findings.

SUMMARY OF BACKGROUND DATA

Eden's classification for dumbbell tumors of the spine, long considered a "gold standard," no longer is sufficient to determine surgical strategy in view of recent advances in computed tomography and magnetic resonance imaging.

METHODS

Forty-two cervical dumbbell tumors were characterized according to transverse-section images (Toyama classification; nine types) and craniocaudal extent of intervertebral and transverse foraminal involvement (IF and TF staging; three stages each).

RESULTS

Type IIIa tumors, involving dura plus an intervertebral foramen, accounted for 50% of cases. A posterior approach was used in 35 patients; 7 others underwent a combined anterior and posterior approach. A posterior approach was used for all type IIa and IIIa tumors, and for some type IIIb (upper cervical), IV, and VI tumors; a combined posterior and anterior approach was used for type IIb and the remainder of type IV and VI. Reconstruction was performed using spinal instrumentation in 4 patients (9.5%). Resection was subtotal in 6 patients (14.3%) and total in 36 (85.7%).

CONCLUSIONS

Systematic, imaging-based three-dimensional characterization of shape and location of cervical dumbbell tumors is essential for planning optimal surgery. The classification used here fulfills this need.

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.

Dumbbell-shaped meningioma with cystic degeneration in the thoracic spine: a case report

STUDY DESIGN

A case report of dumbbell-shaped meningioma in the thoracic spine with cystic degeneration for which a combined posterior microscopic and anterior thoracoscopic approach was used is described.

OBJECTIVES

To report a rare case of dumbbell-shaped meningioma, and to describe a thoracoscopic surgical approach for paravertebral tumor.

SUMMARY OF BACKGROUND DATA

Dumbbell-shaped tumors arising from nerve root sheaths are very common. However, a dumbbell-shaped meningioma is relatively rare, and reports on thoracoscopic resection of dumbbell and paravertebral tumors are still very few in number.

METHODS

The dumbbell meningioma was managed surgically. Because of the paravertebral tumor's intrathoracic expansion, a combined posterior and anterior approach was used. With the posterior approach, microscopic resection using hemilaminotomy was performed, whereas with the anterior approach, the thoracoscopic approach was used instead of thoracotomy.

RESULTS

Complete resection of the tumor was performed successfully. The patient regained his functional ability to walk soon after surgery because of less pain than with thoracotomy.

CONCLUSIONS

With combined microscopic and thoracoscopic surgery, dumbbell-shaped meningioma could be completely resected. The thoracoscopic approach for the removal of a paravertebral tumor can be a good alternative to thoracotomy.

Corpectomy: a direct approach to perimedullary arteriovenous fistulas of the anterior cervical spinal cord

OBJECT

In this report, the authors describe five consecutive patients with cervical perimedullary arteriovenous fistulas (AVFs) that were successfully treated using a corpectomy performed via an anterior approach.

METHODS

Five patients with cervical perimedullary AVF underwent corpectomy via an anterior approach. There were four women and one man who ranged in age from 34 to 62 years (median 55 years). Four patients presented with subarachnoid hemorrhage and one with intramedullary hemorrhage. All five AVFs were located on the anterior surface of the cervical spinal cord and fed by the anterior spinal artery. All patients underwent an anterior approach with 1.5- or two-level corpectomy, opening of the dura mater, and coagulation of the fistula. After dural closure, an iliac bone graft was inserted. Four patients were treated by surgery alone and one patient by embolization and surgery. Postoperative angiography revealed complete disappearance of the AVF in all patients. Neurological status improved in two cases and stabilized in the other three. There were no surgery-related complications.

CONCLUSIONS

Safe and effective interruption of cervical AVFs can be accomplished by an anterior-approach corpectomy.

Far-lateral approach to intradural lesions of the foramen magnum without resection of the occipital condyle

OBJECT

The goal of this study was to determine whether drilling out the occipital condyle facilitates surgery via the far-lateral approach by comparing data from 10 clinical cases with that from studies of eight cadaver heads.

METHODS

During the last 6 years at Louisiana State University Health Sciences Center-Shreveport, 10 patients underwent surgery via the far-lateral approach to the foramen magnum. Six of these patients harbored anterior foramen magnum meningiomas, one patient a dermoid cyst, two patients vertebral artery (VA) aneurysms, and an additional patient suffered from rheumatoid disease of the craniocervical junction. The surgical approach consisted of retromastoid craniectomy and C-1 laminectomy. The seven tumors and the pannus of rheumatoid disease were completely excised, and the two aneurysms were clipped without drilling the occipital condyle. In one patient a chronic subdural hematoma was found 3 months after surgery, but no patient displayed any complication associated with surgery. It is significant that in no patient was a cerebrospinal fluid leak present. All patients experienced improved neurological function postoperatively. To compare surgical visibility, eight cadaveric specimens (16 sides) were studied, including delineation of the VA and its segments around the craniocervical junction. Increase in visibility as a function of fractional removal of the occipital condyle was quantified by measuring the degrees of visibility gained by removing one third and one half of the occipital condyle. Removal of one third of the occipital condyle produced a mean increase of 15.9 degrees visibility, and removal of one half produced a mean increase of 19.9 degrees.

CONCLUSIONS

On the basis of their findings the authors conclude that removal of the occipital condyle is not necessary for the safe and complete resection of anterior intradural foramen magnum tumors.

Lateral interscalenic multilevel oblique corpectomies to repair ventral root avulsions after brachial plexus injury in humans: anatomical study and first clinical experience

OBJECT

Because central nervous system white matter exerts a powerful inhibitory effect on axonal growth, implantation of nerve grafts or rootlets into the cervical spinal cord following ventral root avulsion injury should, ideally, be performed directly through the ventral root exit zone (VRExZ), which is located near the anteromedial aspect of the anterior horn; the grafts/rootlets should not be implanted into the white matter of the lateral cord. This is not possible when using a conservative posterior approach. Therefore, the authors have studied the anatomy encountered when using the anterolateral approach and evaluated the technique in the particular case of avulsed ventral nerve roots. They also present a case illustration of the procedure, which is used currently in their department.

METHODS

Anterior access to the rootlets is obtained using a lateral interscalenic approach; the vertebral artery is exposed and mobilized, and oblique drilling of the vertebral bodies (VBs) is performed. Because the articular processes and half of the VBs are preserved, fusion is not required. The approach allows the surgeon to expose the anterior aspect of the cervical dura and the entire length of the emerging spinal nerves. The anterior aspect of the dura is opened at the desired levels for VRExZ exposure. and the position is ideal for implantation of the graft/rootlets. The interscalenic dissection is mandatory so that the lesions of the supraclavicular plexus can be evaluated and repaired. If necessary, the anterior approach allows for exploration of the infraclavicular plexus during the same procedure.

CONCLUSIONS

The use of a true anterior approach to the ventral rootlets appears to be a valuable and appropriate approach that avoids extensive laminectomy/facetectomy while reimplantation is performed through the anterolateral sulcus itself. In this approach, however, reimplantation of dorsal roots into the spinal cord remains impossible.