Surgical consideration of the intraspinal component in extradural dumbbell tumors

A separate-dural-incision method of extradural dumbbell spinal schwannoma resection: cumulative experience at a single center

OBJECTIVE

To present our experience in the surgical management of completely extradural dumbbell spinal schwannomas with a new surgical strategy.

METHOD

This study is a case series of patients treated at the Neurosurgery Department of the First Affiliated Hospital of USTC, between January 2018 and June 2021.

RESULTS

24 patients met the inclusion criteria, with cervical and lumbar spines being the most frequent locations. All patients underwent surgical treatment. Total gross resection was accomplished in all patients. Two cases had numbness and no case exhibited motor deficit. There was no postoperative CSF leakage or wound infection.

CONCLUSION

Based on a limited number of observations, we conclude that our technique was feasible and effective for the treatment of extradural dumbbell spinal schwannomas.

CLINICAL TRIAL

http://www.chictr.org.cn/ , No. ChiCTR2400086171.

Surgical outcomes in instrumented surgery for dumbbell type spinal cord tumor -the comparison with non-instrumented surgery for spinal cord tumor

BACKGROUND

There is little information on outcomes for spinal cord tumor treated surgically with instrumentation. Analysis of surgical outcomes and complications in such cases is needed to develop generalizable conclusions and to help inform patients.

METHODS

The subjects were 41 patients treated with instrumentation surgery for dumbbell type tumor resection. Demographic data; tumor histology, level, and location; number of fused vertebra; use of a bilateral or hemilateral screw; operative time; EBL; TcMEP monitoring; lumbar subarachnoid drainage; duration of subfascial drainage; postoperative motor and sensory deficits; CSF leakage, implant-related complications; time for union of fused vertebra; salvage surgeries, and pre-/postoperative McCormick scale were obtained from medical records. Significant factors related to postoperative motor deficits were identified.

RESULTS

Postoperative motor deficit occurred in 9 cases (22.0%) and all recovered in 30 days after surgery. CSF leakage at 7 days and 2 years after surgery was subfascial (n = 31, n = 6) and subcutaneous (n = 3, n = 4). Cases with postoperative motor deficits more commonly had lower cervical lesions; those with CSF leakage had longer operative times; and those with delayed union had more use of hemilateral instrumentation.

CONCLUSION

In this study in 41 spinal cord tumors treated surgically with instrumentation, the rate of postoperative motor deterioration was 22.0%, and CSF leakage was found in 17.1%.

Subaxial lateral mass prosthesis for posterior reconstruction of cervical spine

PURPOSE

To obtain the relevant morphometry of the lateral mass of the subaxial cervical spine (C3-C7) and to design a series of lateral mass prostheses for the posterior reconstruction of the stability of cervical spine.

METHODS

The computed tomography (CT) scans of healthy volunteers were obtained. RadiAnt DICOM Viewer software (Version 2020.1, Medixant, Poland) was used to measure the parameters of lateral mass, such as height, anteroposterior dimension (APD), mediolateral dimension (MLD) and facet joint angle. According to the parameters, a series of cervical lateral mass prostheses were designed. Cadaver experiment was conducted to demonstrate its feasibility.

RESULTS

23 volunteers with an average age of 30.1 ± 7.1 years were enrolled in this study. The height of lateral mass is 14.1 mm averagely. Facet joint angle, APD and MLD of lateral mass averaged 40.1 degrees, 11.2 mm and 12.18 mm, respectively. With these key data, a lateral mass prosthesis consists of a bone grafting column and a posterior fixation plate was designed. The column has a 4.0 mm radius, 41 degrees surface angle and adjustable height of 13, 15, or 17 mm. In the cadaver experiment, the grafting column could function as a supporting structure between adjacent facets, and it would not violate exiting nerve root (NR) or vertebral artery (VA).

CONCLUSION

This study provided detailed morphology of the lateral mass of subaxial cervical spine. A series of subaxial cervical lateral mass prostheses were designed awaiting further clinical application.

Resection of cervical extra-intraspinal neuromas through the enlarged intervertebral foramen: Results in 34 case series patients

Objective

The purpose of this study was to analyze the techniques used to resection cervical extra-intraspinal neuromas (also known as cervical dumbbell neuromas) through the enlarged intervertebral foramen.

Methods

A total of 34 consecutive patients (19 male, 15 female) with cervical dumbbell neuromas reviewed retrospectively between April 2008 and May 2020. Sixteen tumors were found in the intervertebral foramen of C₁-C₃, four in C₃-C₄, and 14 in C₄-T₁. The approach in all cases was to expose the tumors by intermuscular dissection and to remove them through the enlarged intervertebral foramen without excision of any bony structures. However, to expose tumors at different locations, the incisions shall be made accordingly. In this case series, the incisions were made along the posterior border of the sternocleidomastoid muscle for the C₁-C₃ tumors and along the anterior border of the muscle for the C₃-C₄ tumors. Transverse incisions were required for the C₄-T₁ tumors.

Results

Following the mentioned incising approach, all 34 tumors were completely exposed. 31 were completely removed in one stage, and 3 tumors underwent subtotal resection because of brachial plexus nerve adhesion. The vertebral artery and spinal cord were undamaged for all cases. The patients who had total tumor resection showed no sign of recurrence on enhanced magnetic resonance imaging during follow-ups. The status of patients who underwent subtotal resection was stable after radiation therapy. None of the patients developed spinal instability.

Conclusions

Cervical dumbbell neuromas can be exposed and removed through the enlarged intervertebral foramen without causing spinal instability or injury to the spinal cord or vertebral artery. This operative approach can retain the integrity of the structures of spine and should be considered the ideal approach for cervical dumbbell neuromas.

Efficacy of One-stage Paravertebral Approach using a Micro-Tubular Technique in Treating Thoracic Dumbbell Tumors

OBJECTIVE

The aim of the present study was to investigate the feasibility and efficacy of one-stage surgical resection of thoracic dumbbell tumors using a paravertebral approach and a micro-tubular technique.

METHODS

Clinical data of thoracic dumbbell tumors resected using a paravertebral approach and a micro-tubular technique (14 mm, non-expandable type) in the Department of Neurosurgery at our hospital from July 2014 to July 2019 were retrospectively analyzed. Tumors were found between T1 and T12 vertebrae. Operation time, blood loss, hospitalization, recovery of neurological function, complications, the Japanese Orthopaedic Association (JOA) score, and the visual analogue scale (VAS) score were used to evaluate clinical efficacy.

RESULTS

In all 31 cases, tumors were completely resected in one operation, with a mean blood loss of 53.23 ± 33.08 mL (20-150 mL) and a mean operation time of 95.16 ± 20.31 min (60-180 min). According to the Eden classification, there were four type II cases, 16 type III cases, and 11 type IV cases. The incidence of tumors in the lower thoracic segment (T8-T12) was 51.6% (16/31 cases), while the incidences in the upper thoracic segment (T1-T4) and middle segment (T5-T8) were 25.8% (8/31 cases) and 22.6% (7/31 cases), respectively. Pathological diagnoses were schwannoma (n = 22), gangliocytoma (n = 4), metastatic tumor (n = 2), neurofibroma (n = 1), granuloma (n = 1), and lipoma (n = 1). After surgery, symptoms were relieved in all patients. VAS and JOA scores significantly improved (P < 0.001). There was no pleural or lung injury, and there were no complications, such as cerebrospinal fluid leakage. The average follow-up duration was 29 months (13-59 months), during which time no tumor recurrence or spinal instability occurred. The group of Eden type II tumors had lower JOA scores at 12 months postoperatively, longer operation times, and more estimated blood loss compared with other groups (P < 0.05). There were no significant influences on VAS scores at 12 months postoperatively and postoperative hospital stay from the different types of tumors.

CONCLUSION

The paravertebral approach with a micro-tubular technique is a safe and effective minimally invasive surgical approach for thoracic dumbbell tumors that allows one-stage tumor resection using a single incision. Using this approach significantly reduces intraoperative blood loss and postoperative complications, shortens hospital stay, and reduces the rates of postoperative spinal instability.

A Novel Classification and Its Clinical Significance in Spinal Schwannoma Based on the Membranous Hierarchy

BACKGROUND

Spinal schwannoma is a common benign tumor. However, the high recurrence rate and incidence of surgical complications are unsolved problems.

OBJECTIVE

To propose a morphological classification of spinal schwannoma based on tumor-membrane relationships to increase the gross total resection (GTR) rate and to decrease the incidence of surgical complications.

METHODS

Histological techniques were used to study 7 adult cadavers. Following picrosirius staining, the membranes around the nerve root were observed under a microscope. Data from 101 patients with spinal schwannoma were also collected for clinical analysis.

RESULTS

The sleeve around the spinal nerve root consisted of dura and arachnoid tissues. The space between them gradually narrowed and fused at the proximal pole of the nerve root ganglion. Spinal schwannomas were divided into 4 types based on membranous structure: intrapial (type I), subarachnoidal (type II), intra- and extradural (type III), and extradural growth (type IV). Types II and III were further subdivided into 2 subtypes. GTR was achieved in all patients (100%), with no tumor recurrence during follow-up. Overall functional status significantly improved postoperatively. A total of 59 patients (92%) showed improvement or significant improvement postoperatively. There was no difference in surgical outcomes among the tumor classifications (P = .618). No intraoperative vertebral artery injuries or postoperative cerebrospinal fluid fistula occurred.

CONCLUSION

Spinal schwannoma classification based on a membranous hierarchy provides an intuitive platform for preoperative planning and intraoperative safety. This classification scheme may help surgeons better define surgical goals and anticipate or even avoid complications from resection.

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.

Surgical Strategy for Spinal Dumbbell Tumors: A New Classification and Surgical Outcomes

STUDY DESIGN

One hundred twenty-four patients with spinal dumbbell tumors were analyzed retrospectively using a new classification.

OBJECTIVE

To recommend a novel classification of spinal dumbbell tumors based on the characteristics of surgical approach.

SUMMARY OF BACKGROUND DATA

Current classifications of cervical dumbbell tumor are excessively convoluted with an impractical number of variables or lack of quantitative indicators for the choice of surgical approach, and there are few classifications described in the literature which related to thoracic or lumbar dumbbell tumors. An ideal classification must be simple and reproducible based on commonly identified clinical and radiographic parameters.

METHODS

The clinical records of a series of 124 patients with spinal dumbbell tumors were analyzed retrospectively using a new classification. We divided the largest transverse section of the tumor into four areas, and different areas need different surgical procedures.

RESULT

Ninety-two patients were treated using the posterior approach alone, 13 patients underwent surgery by lateral cervical approach, and 19 cases were excised using combined anterior and posterior approach. Tumors total removal was 123 cases, with partial resection in one patient. Concomitant spinal fixation and fusion was performed in 18 patients. A total of 97 cases had follow-up with clinical and radiographic outcome variables ranged from 12 to 52 months (mean, 46.3 months). Eighty-eight patients (90.7%) had clinical improvement, whereas clinical status was the same in seven (7.2%), two patients (2.1%) demonstrated neurologic deterioration, and magnetic resonance imaging at last follow-up revealed no recurrence in any patient.

CONCLUSION

The new classification of spinal dumbbell tumors is a simple way of identifying patients who require a different surgical approach.

LEVEL OF EVIDENCE

4.

Surgical nuances on the treatment of giant dumbbell cervical spine schwannomas: description of a challenging case and review of the literature

We report a case of a giant intra and extradural cervical schwannoma in a patient affected by a severe myelo-radiculopathy. Clinical features, diagnosis and the issues concerning the surgical management of this benign tumor are discussed. We also review similar cases previously reported in the literature. A 50-year old caucasian woman was complaining of a 1 year of neck pain and worsening motor impairment in all four limbs causing the inability to walk. Neuroradiological assessment revealed a suspected schwannoma involving the nerve roots from C3 to C5, compressing and deviating the spinal cord. The vertebral artery was also encased within the lesion, but still patent. A posterior cervical laminectomy with a microsurgical extradural resection of the lesion was performed. Moreover, an accurate dissection of the lesion from the vertebral artery and the resection of the intraspinal component was achieved. Vertebral fixation with screws on the lateral masses of C3, C5 and C6 and a hook on C1 was performed. The procedure was secured using electroneurophysiological monitoring. A progressive improvement of the motor functions was achieved. A cervical post-contrast MRI revealed optimal medullary decompression and a gross-total resection of the lesion. Schwannomas are benign, slowly growing lesions which may cause serious neurological deficit. Early diagnosis is necessary and it maybe aided by imaging studies such as MRI or CT. The accepted treatment for these tumors is surgical resection and, when indicated, vertebral fixation.

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.

Surgical consideration of cervical dumbbell tumors

BACKGROUND

Nineteen patients with cervical dumbbell tumors treated surgically were analyzed retrospectively.

METHODS

Surgical strategies for dumbbell tumor were discussed from the perspective of safe, less-invasive surgery.

RESULTS

Patients included 6 men and 13 women, with a mean age at the time of surgery of 48.3 years (range, 25-70 years). Underlying pathologies included 16 schwannomas, 2 neurofibromas, and 1 double tumor (schwannoma and meningioma). According to Eden's classification, one patient was classified as Type 1, 5 as Type 2, 8 as Type 3, and 5 as Type 4. In 13 cases, tumors were excised through the posterior approach alone, compared to five cases using the anterior approach. One case was excised using combined anterior and posterior approaches. Facetectomy was not performed in 18 cases. In one case, the facet joint on one side had already destroyed and needed instrumentation. Tumors were totally excised in all cases. Postoperatively, the patients did not display any further neurological deficit, with the exception of transient radiculopathy in two patients. Major surgical complications and cerebrospinal fluid leakage were not seen. Tumor recurrence and spinal segmental instability were not found during follow-up period (mean, 41.6 months).

CONCLUSIONS

Dumbbell tumor surgery requires sufficient debulking of the epidural and paravertebral mass, using intraoperative nerve stimulation and Doppler ultrasonography to detect the vertebral artery. When using a posterior approach, recapping laminoplasty using an ultrasonic bone curette is very useful to remove tumor without sacrificing facet joints.

Minimally invasive microsurgical treatment of cervical intraspinal extramedullary tumors

Removal of intraspinal tumors by the classic posterior midline approach with laminectomy may cause damage to and instability of cervical segments. We investigated whether the less invasive hemilaminectomy or hemi-semi-laminectomy can achieve satisfactory clinical outcomes in 39 patients with intraspinal extramedullary tumors of the cervical spine. Twenty-seven patients were treated with conventional microsurgery using a posterior midline approach; and were compared to 12 patients treated with hemilaminectomy or hemi-semi-laminectomy using a posterior midline approach. Patients were retrospectively reviewed and their preoperative and postoperative clinical status was measured using the Frankel Grade. The surgical time for the 27 patients who underwent a classical laminectomy was 3±0.39 hours and blood loss was 123±34 mL. Twenty-five patients had their tumors removed entirely, and two patients had partial removal. Twenty-six patients were followed-up for between 38 months and 7 years (mean=5 years), of whom 23 improved and three remained in a stable condition. One patient with a meningioma had a tumor recurrence 3 years post-operatively and underwent further surgery. The surgical time for the hemilaminectomy or hemi-semi-laminectomy group was 2.5±0.3 hours and blood loss was 88±18 mL. All patients were followed-up for between 26 and 42 months (mean=31 months) and 11 recovered to an improved grade while one remained in a stable condition. No patient had a tumor recurrence. The hemilaminectomy or hemi-semi-laminectomy approach achieved similar clinical outcomes to the conventional posterior midline laminectomy approach and was also associated with a shorter operative time, decreased intraoperative blood loss, greater preserved ligament and bone structure and a reduced deformity rate.