Surgery for ventral intradural thoracic spinal tumors with a posterolateral transpedicular approach

Minimally Invasive Far-Lateral Hybrid Exoscopic-Endoscopic Lateral Rolling Technique for T1-2 Anterior Intradural Extramedullary Meningioma

Anterior intradural extramedullary meningiomas are intimidating, especially in the thoracic spine due to the spinal cord impeding conventional surgical corridor, restricted space, and precarious cord vascularity.1,2 This is possibly the first report in the literature of a minimally invasive surgery: far-lateral hybrid exoscopic and angled endoscopic approach for an anterior thoracic spine meningioma. A 60-year-old woman presented with an anterior T1-2 meningioma with a flattened cord draping over the tumor more toward the right, leaving a potential corridor on the left lateral aspect (Video 1). Under a three-dimensional exoscope, a minimally invasive retractor was placed through the left paramedian incision centered on the lamina-transverse process junction; lateral fenestration and T1-2 facetectomy were carried out with a high-speed drill and rongeurs, meticulously preserving C7-T1 articulations.3,4 Following coagulation of the anterolateral dura over the tumor, a lateral longitudinal durotomy with a T-shaped anterolateral extension was performed around the tumor. Following devascularization, disconnection, and extra-arachnoidal dissection, a unique lateral rolling technique was employed, wherein the tumor was bimanually rolled onto the bony gutter created earlier without disturbing the spinal cord. This was followed by coagulation and excision of the dural tail. A 45° endoscope was then inserted to look for any residual tumor or dural tail.5 As the durotomy was lateral with excision of the dural tail, a multilayered soft tissue closure without dead space was sufficient to prevent cerebrospinal fluid leak.3 Fixation was not needed as only a single thoracic spine facet was disrupted.4 The patient recovered fully with radiology confirming total excision. This minimally invasive lateral rolling technique is safe and effective for anterior meningioma with the ergonomics of exoscope & the angled optics of endoscope complementing each other.

Modified Unilateral Approach for Ventrally Located Spinal Tumors

Surgery on spinal tumors becomes challenging when the tumor is ventral to the spinal cord. Conventionally, we approach it posteriorly through bilateral laminectomy and rotate the cord after sectioning the dentate ligament and nerve roots. However, manipulating the cord can be hazardous, and a long bilateral laminectomy can be invasive. Meanwhile, a narrow operative field and a limited lateral viewing angle in a unilateral approach constrained the surgeon. To overcome these problems, we previously reported a technique of modified unilateral approach where we incised the skin and the fascia horizontally and placed a pair of retractors longitudinally.The current article reports our experience applying this approach in 15 patients with ventrally located spinal tumors. The approach was performed on 10 schwannomas, 2 meningiomas, and 3 others. We evaluated paraspinal muscle atrophy on postoperative magnetic resonance imaging.The modified unilateral approach provided an excellent surgical field for removing ventrally located tumors. Gross total removal was achieved in 11 patients (92% of benign tumors). No neurological complications occurred except for one case of transient weakness. We encountered no wound-related late complications such as pain or deformity. The reduction of the cross-sectional area of the paraspinal muscles on the approach side (compared to the nonapproach side) was 0.93 (95% confidence interval: 0.72-1.06), indicating 7% atrophy (statistically nonsignificant, p = 0.48).We believe this simple technique can be useful for removing spinal tumors located ventral to the spinal cord.

Indications for Fusion With Intradural Spine Tumor Resection in Adults: A Systematic Review and Meta-analysis

BACKGROUND

The evidence for instrumented fusion in the setting of degenerative, traumatic, or congenital deformity is well established. Data on fusion indications in intradural spinal tumors (IDST) are scarce and reduced to retrospective studies. The objective of this work is to systematically review the published literature since 2015 and analyze the change of practice patterns for stabilization and fusion after intradural tumor resection in adults.

METHODS

A systematic literature review was performed via PubMed with the terms: "intradural spinal tumors", "intramedullary spinal tumors", and "intraspinal tumors". The analysis was limited to adult patients with IDST and studies with more than 10 patients. Data on the proportion of patients who underwent instrumentation and had postoperative deformity was pooled in a meta-analysis.

RESULTS

A total of 1073 articles were identified and 47 papers were selected. All the studies were retrospective series and a total of 2473 patients were included. The follow-up ranged from 1 to 96 months, the pooled spinal fixation rate was 6% (95% CI 4.5%-7.6%), the pooled laminoplasty rate was 14.4% (95% CI 5.9%-23%), the pooled rate of postoperative deformity or malalignment in patients with a follow up of at least 6 months was 2.1% (95% CI 1.2%-3%) and just 7 patients were reoperated due to progressive deformity.

CONCLUSIONS

Based on existing evidence, the rate of fusion during resection of intradural spinal tumors is low. Prophylactic fixation is often unnecessary and only indicated in unique cases that require extensive bony resection.

Mid- to Long-Term Outcomes After Resection of Thoracic Dumbbell Tumors Managed by Laminectomy and Unilateral Total Facetectomy Without Instrumented Fusion

STUDY DESIGN

Retrospective multicenter study.

OBJECTIVE

To evaluate mid- to long-term surgical outcomes of thoracic dumbbell tumors managed by laminectomy and unilateral total facetectomy without instrumented fusion.

METHODS

A total of 15 patients with thoracic dumbbell tumors who underwent primary resection by laminectomy and unilateral total facetectomy without spinal instrumented fusion between 2000 and 2015 were reviewed. Patient characteristics, surgical outcomes (including spinal alignment and stability), disc degeneration, pain, disability, and health-related quality of life were evaluated. Additionally, to analyze the impact of the affected levels on these outcomes, we divided the patients into 2 groups: a middle thoracic group and a thoracolumbar group.

RESULTS

The mean duration of follow-up was 100.5 months (range, 36-190 months). The affected level was T3-T4 or below in all patients. Although the local kyphosis angle (8.1° to 12.7°), thoracic kyphosis angle (25.6° to 33.9°), and coronal Cobb angle (6.6° to 9.5°) significantly increased from preoperative to the final visit (P ≤ .02), no patient demonstrated spinal instability. From magnetic resonance imaging, no patient had a worse grade of disc degeneration in the affected level than those in the adjacent levels. The percentage of patients who presented with an Oswestry disability index ≤ 22% was 80%. Moreover, the surgical region did not adversely affect the outcomes. No patient required additional surgery due to spinal instability or deformity.

CONCLUSIONS

Unilateral total facetectomy without fusion to resect thoracic dumbbell tumors caused neither spinal deformity nor instability requiring additional surgery at the mid- to long-term follow-up.

Posterolateral transpedicular approach for ventrally seated cervicothoracic spinal cord lesions: how I do it

BACKGROUND

Surgical exposure of lower cervical and upper thoracic intradural extramedullary lesions located along the ventral medulla are among the most complexes to address in spinal surgery, and their surgical removal carries a high risk.

METHODS

We describe the surgical steps of a posterolateral transpedicular approach for resection of an intradural extramedullary lesion located anterolaterally at C7-T1 level.

CONCLUSIONS

A posterolateral transpedicular approach is a safe and efficient surgical corridor to explore the ventral spinal cord and to have a direct access to lower cervical-upper thoracic lesions without the extensive manipulation of the spinal cord and the spine instability.

Clinical characteristics and long-term outcomes for patients who undergo cytoreductive surgery for thoracic meningiomas: a retrospective analysis

OBJECTIVE

Primary spinal meningiomas represent a rare indolent neoplasm usually situated in the intradural-extramedullary compartment. They have a predilection for afflicting the thoracic spine and most frequently present with sensory and/or motor symptoms. Resection is the first-line treatment for symptomatic tumors, whereas other clinical factors will determine the need for adjuvant therapy. In this study, the authors aimed to elucidate clinical presentation, functional outcomes, and long-term outcomes in this population in order to better equip clinicians with the tools to counsel their patients.

METHODS

This is a retrospective analysis of patients treated at the authors' institution between 1998 and 2018. All patients with thoracic meningiomas who underwent resection and completed at least one follow-up appointment were included. Multiple preoperative clinical variables, hospitalization details, and long-term outcomes were collected for the cohort.

RESULTS

Forty-six patients who underwent resection for thoracic meningiomas were included. The average age of the cohort was 59 years, and the median follow-up was 53 months. Persistent sensory and motor symptoms were present in 29 patients (63%). Fifteen lesions were ventrally positioned. There were 43 WHO grade I tumors, 2 WHO grade II tumors, and 1 WHO grade III tumor; the grade III tumor was the only case of recurrence. The median length of hospitalization was 4 days. Seventeen patients (37%) were discharged to rehabilitation facilities. Thirty patients (65.2%) experienced resolution or improvement of symptoms, and there were no deaths within 30 days of surgery. Only 1 patient developed painful kyphosis and was managed medically. Ventral tumor position, new postoperative deficits, and length of stay did not correlate with disposition to a facility. Age, ventral position, blood loss, and increasing WHO grade did not correlate with length of stay.

CONCLUSIONS

Outcomes are overall favorable for patients who undergo resection of thoracic meningiomas. Symptomatic patients often experience improvement, and patients generally do not require significant future operations. Tumors located ventrally, while anatomically challenging, do not necessarily herald a significantly worse prognosis or limit the extent of resection.

A transpedicular approach to complex ventrally situated thoracic intradural extramedullary tumors: technique, indications, and multiinstitutional case series

OBJECTIVE

Ventrally situated thoracic intradural extramedullary tumors are surgically challenging and difficult to access, and they may be complicated by extensive adhesions and calcifications. Selecting an approach for adequate ventral access is key to complete resection and optimization of outcomes. The authors present a case series of patients who underwent resection of ventral thoracic intradural extramedullary tumors and discuss indications and considerations for this technique. Additionally, they describe the use of a posterolateral transpedicular approach for resection of ventral thoracic intradural extramedullary tumors compared with other techniques, and they summarize the literature supporting its application.

METHODS

From May 2017 to August 2020, 5 patients with ventral thoracic intradural extramedullary tumors underwent resection at one of the two academic institutions.

RESULTS

Patient ages ranged from 47 to 75 (mean 63.4) years. All tumors were diagnosed as meningiomas or schwannomas by histological examination. Three of the 5 patients had evidence of partial or extensive tumor calcification. Four of the 5 patients underwent an initial posterolateral transpedicular approach for resection, with positive radiographic and clinical outcomes from surgery. One patient initially underwent an unsuccessful traditional direct posterior approach and required additional resection 2 years later after interval disease progression. There were no postoperative wound infections, CSF leaks, or other complications related to the transpedicular approach.

CONCLUSIONS

Posterolateral transpedicular tumor resection is a safe technique for the treatment of complex ventrally situated thoracic intradural extramedullary tumors compared with the direct posterior approach. Anecdotally, this approach appears to be particularly beneficial in patients with calcified tumors.

Low recurrence after Simpson grade II resection of spinal benign meningiomas in a single-institute 10-year retrospective study

The objective of this study was to more fully understand the optimal neurosurgical strategy for spinal benign meningiomas from a medium to long-term perspective. This retrospective study included a cohort of 35 patients with a diagnosis of spinal meningioma who were first operated at our institute over the past 10 years and followed-up for at least 2 years after surgery. The inclusion criterion for the study was the pathological diagnosis finally verified as benign meningioma of World Health Organization (WHO) grade 1. The average follow-up duration after surgery was 61.0 months. The location of the spinal meningioma was classified into ventral or dorsal type based on the operative video record and the preoperative MR images. The extent of resection of the spinal meningioma was carefully determined based on the Simpson grade. The average neurological condition was significantly improved at the final follow-up. Simpson grade I or II resection was achieved in 31 of 35 cases (88.6%). No Simpson grade I or II cases showed local recurrence during follow-up. Tumor recurrence was noted in 2 of 4 cases of Simpson grade IV resection. One case has been followed-up without any re-operation because of no neurological deterioration, and the other case underwent stereotactic radiosurgery. This study suggested that meticulous Simpson grade II resection of spinal benign meningiomas of WHO grade 1 may be good enough from a medium to long-term follow-up perspective, though longer follow-up is absolutely necessary.

Need for arthrodesis following facetectomy for spinal peripheral nerve sheath tumors: an institutional experience and review of the current literature

OBJECTIVE

Spinal peripheral nerve sheath tumors (PNSTs) are a group of rare tumors originating from the nerve and its supporting structures. Standard surgical management typically entails laminectomy with or without facetectomy to gain adequate tumor exposure. Arthrodesis is occasionally performed to maintain spinal stability and mitigate the risk of postoperative deformity, pain, or neurological deficit. However, the factors associated with the need for instrumentation in addition to PNST resection in the same setting remain unclear.

METHODS

An institutional tumor registry at a tertiary care center was queried for patients treated surgically for a primary diagnosis of spinal PNST between 2002 and 2016. An analysis focused on patients in whom a facetectomy was performed during the resection. The addition of arthrodesis at the index procedure comprised the primary outcome. The authors also recorded baseline demographics, tumor characteristics, and surgery-related variables. Logistic regression was used to identify factors associated with increased risk of fusion surgery.

RESULTS

A total of 163 patients were identified, of which 56 (32 had facetectomy with fusion, 24 had facetectomy alone) were analyzed. The median age was 48 years, and 50% of the cohort was female. Age, sex, and race, as well as tumor histology and size, were evenly distributed between patients who received facetectomy alone and those who had facetectomy and fusion. On univariate analysis, total versus subtotal facetectomy (OR 9.0, 95% CI 2.01-64.2; p = 0.009) and cervicothoracic versus other spinal region (OR 9.0, 95% CI 1.51-172.9; p = 0.048) were significantly associated with increased odds of performing immediate fusion. On multivariable analysis, only the effect of total facetectomy remained statistically significant (OR 6.75, 95% CI 1.47-48.8; p = 0.025).

CONCLUSIONS

The authors found that total facetectomy and cervicothoracic involvement may be highly associated with the need for concomitant arthrodesis at the time of index surgery. These findings may help surgeons to determine the best surgical planning for patients with PNST.

Discrimination between spinal extradural meningioma and both intra and extradural meningioma: Case Report

Meningiomas are common spinal tumor and mostly located at intradura. Recurrence rate after surgery for extradural meningioma was higher than intradural meningioma. A patient with intra and extradural spinal meningioma was treated and discussed its features and clinical management. A 41-year-old woman noted numbness of bilateral legs, gait disturbance, and mild bladder disturbance for over the two-month period. Magnetic resonance imaging revealed an epidural mass at T8-9 involving the dura mater from the left side. Intraoperatively, ultrasonography showed extradural tumor suppress the dura from the left side and no subarachnoid space. Therefore, it was difficult to diagnose the tumor was located at only extradural or both intra and extradural. The extradural tumor was resected as much as possible, then ultrasonography was performed for the second time. The spinal cord was decompressed and subarachnoid space was appeared with intradural tumor. The dura mater was opened in the midline for intradural exploration, and the intradural tumor appeared beside the spinal cord. The dura mater with attachment to the tumor was rescected. To prevent a recurrence, ultrasonography after removing extradural tumor is recommended to detect intra dural tumor and invasion of tumor into dura mater. In such case, removing only extradural meningioma is not enough, and gross total resection including intradural meningioma and dura mater is required.