Posterior approach to ventrally located spinal meningiomas

Current Knowledge on Spinal Meningiomas-Surgical Treatment, Complications, and Outcomes: A Systematic Review and Meta-Analysis (Part 2)

Background: Most of the knowledge on spinal meningiomas is extrapolated from their intracranial counterparts, even though they are considered separate entities. This review aimed to systematically summarize studies covering different aspects of spinal meningiomas and their management. Methods: Databases were searched for all studies concerning spinal meningiomas dating from 2000 and onwards. When possible, a meta-analysis was performed. Results: Neurological outcomes of surgery were consistently favorable across studies, with a complication rate of 7.9% and 78.9% of the patients demonstrating good postoperative neurological function (McCormick score 1−2). The most relevant predictors of unfavorable outcomes were poor preoperative status, longer time from diagnosis to surgery, and surgery of recurrent tumors. The recurrence rate after surgery was estimated at 6%. Meta-analysis and/or survival analysis revealed that higher WHO grade (p < 0.001), higher Simpson grade (p < 0.001), ventral tumor location (p = 0.02), and male sex (p = 0.014) were all associated with higher odds of recurrence. However, the meta-analysis did not show any difference between Simpson grade 1 and grade 2 with respect to the odds of recurrence (p = 0.94). Surgery provided immediate and durable health-related quality-of-life improvement, as well as a high frequency of return to work. Conclusion: Spinal meningioma surgery is a relatively safe procedure with a low risk of tumor recurrence and high likelihood of favorable postoperative outcomes.

Unsuccessful external validation of the MAC-score for predicting increased MIB-1 index in patients with spinal meningiomas

OBJECTIVE

Recently, the MAC-spinal meningioma score (MAC-score) was proposed to preoperatively identify spinal meningioma patients with high MIB-1 indices. Risk factors were age ≥ 65 years, a modified McCormick score (mMCs) ≥ 2, and absence of tumor calcification. The aim of this study was to externally validate the MAC-score in an independent cohort.

METHODS

Using the same inclusion and exclusion criteria as in the original study, we performed a retrospective, single-center, population-based, cohort study that included patients who had undergone surgical treatment for spinal meningiomas between 2005 - 2017. Data was collected from patient charts and radiographic images. Validation was performed by applying the MAC-score to our cohort and evaluating the area under the receiver operating characteristic curve (AUC).

RESULTS

In total, 108 patients were included. Baseline and outcome data were comparable to the original development study. An increased MIB-1 index (≥5%) was observed in 56 (52%) patients. AUC of the MAC-score in our validation cohort was 0.61 (95% CI: 0.51 - 0.71), which corresponds to a poor discriminative ability.

CONCLUSION

The MAC-score showed poor discriminative ability for MIB-1 index prediction in patients with spinal meningiomas. Moreover, the MAC-score rests on a weak theoretical and statistical foundation. Consequently, we argue against its clinical implementation.

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.

Oncologic benefits of dural resection in spinal meningiomas: a meta-analysis of Simpson grades and recurrence rates

OBJECTIVE

While resection of the dural attachment has been shown by Simpson and others to reduce recurrence rates for intracranial meningiomas, the oncological benefit of dural resection for spinal meningiomas is less clear. The authors performed a systematic analysis of the literature, comparing recurrence rates for patients undergoing various Simpson grade resections of spinal meningiomas to better understand the role of dural resection on outcomes after resection of spinal meningiomas.

METHODS

The PubMed/Medline database was systematically searched to identify studies describing oncological and clinical outcomes after Simpson grade I, II, III, or IV resections of spinal meningiomas.

RESULTS

Thirty-two studies describing the outcomes of 896 patients were included in the analysis. Simpson grade I, grade II, and grade III/IV resections were performed in 27.5%, 64.6%, and 7.9% of cases, respectively. The risk of procedure-related complications (OR 4.75, 95% CI 1.27-17.8, p = 0.021) and new, unexpected postoperative neurological deficits (OR ∞, 95% CI NaN-∞, p = 0.009) were both significantly greater for patients undergoing Simpson grade I resections when compared with those undergoing Simpson grade II resections. Tumor recurrence was seen in 2.8%, 4.1%, and 39.4% of patients undergoing Simpson grade I, grade II, and grade III/IV resections over a mean radiographic follow-up period of 99.3 ± 46.4 months, 95.4 ± 57.1 months, and 82.4 ± 49.3 months, respectively. No significant difference was detected between the recurrence rates for Simpson grade I versus Simpson grade II resections (OR 1.43, 95% CI 0.61-3.39, p = 0.43). A meta-analysis of 7 studies directly comparing recurrence rates for Simpson grade I and II resections demonstrated a trend toward a decreased likelihood of recurrence after Simpson grade I resection when compared with Simpson grade II resection, although this trend did not reach statistical significance (OR 0.56, 95% CI 0.23-1.36, p = 0.20).

CONCLUSIONS

The results of this analysis suggest with a low level of confidence that the rates of complications and new, unexpected neurological deficits after Simpson grade I resection of spinal meningiomas are greater than those seen with Simpson grade II resections, and that the recurrence rates for Simpson grade I and grade II resections are equivalent, although additional, long-term studies are needed before reliable conclusions may be drawn.

Microscopic Keyhole Technique for Surgical Removal of Thoracic Spinal Meningiomas

OBJECTIVE

The aim of this study was to evaluate the safety and efficacy of the microscopic minimally invasive keyhole technique for surgical resection of thoracic spinal meningiomas.

METHODS

Seventeen consecutive patients with thoracic spinal meningiomas were included in the series from May 2015 to August 2017. All patients were treated using a microscopic keyhole technique through a tubular retractor system. The demographic data and perioperative variables were recorded. At last follow-up, clinical outcome was assessed using the visual analog scale for pain and the American Spinal Injury Association scale for motor and sensory outcome.

RESULTS

All patients underwent microscopic keyhole surgery and complete resection was achieved. Mean operative time was 153.2 minutes (range 115-300 minutes). Mean blood loss during surgery was 110.3 mL (range 50-175 mL). No infection or aggravation of spinal cord injury occurred after operation, except for 2 patients who had postoperative cerebrospinal fluid leakage that recovered after conservative treatment. The mean duration of hospital stay was 6.8 days (range 5-10 days). At the last follow-up, all patients had a reduced level of pain as suggested by an average visual analog scale score that improved from 7.6 to 0.2. The American Spinal Injury Association grade improved or remained normal in all patients except 1. No evidence of tumor recurrence or secondary spinal deformity was observed in any patients during the postoperative follow-up period, and spinal stabilities were found to be satisfactory.

CONCLUSIONS

Based on our results, the microscopic minimally invasive keyhole technique can be used safely and effectively for resection of thoracic spinal meningiomas.

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.

The lateral extracavitary approach to the thoracolumbar spine: a case series and systematic review

OBJECT

Since its introduction in 1976, the lateral extracavitary approach (LECA) has been used to access ventral and ventrolateral pathology affecting the thoracolumbar spine. Reporting of outcomes and complications has been inconsistent. A case series and systematic review are presented to summarize the available data.

METHODS

A retrospective review of medical records was performed, which identified 65 consecutive patients who underwent LECA for the treatment of thoracolumbar spine and spinal cord pathology. Cases were divided according to the presenting pathology. Neurological outcomes and complications were detailed. In addition, a systematic review of outcomes and complications in patients treated with the LECA as reported in the literature was completed.

RESULTS

Sixty-five patients underwent the LECA to the spine for the treatment of thoracic spine and spinal cord pathology. The most common indication for surgery was thoracic disc herniation (23/65, 35.4%). Neurological outcomes were excellent: 69.2% improved, 29.2% experienced no change, and 1.5% were worse. Two patients (3.1%) experienced a complication. The systematic review revealed comparable neurological outcomes (74.9% improved) but a notably higher complication rate (32.2%).

CONCLUSIONS

The LECA provides dorsal and unilateral ventrolateral access to and exposure of the thoracolumbar spine and spinal cord while allowing for posterior instrumentation through the same incision. Although excellent neurological results can be expected, the risk of pulmonary complications should be considered.

Long-term recurrence rates after the removal of spinal meningiomas in relation to Simpson grades

PURPOSE

Simpson grade II removal (coagulation of the dural attachment after gross total removal) of spinal meningioma is considered an acceptable alternative, but increased recurrence after more than 10 years has been reported. More attention must be paid to the long-term surgical outcomes after Simpson grade II removal.

METHODS

A retrospective review was performed for 20 patients (M:F = 5:15; age, 59 ± 9 years) with Simpson grade II removal (mean follow-up period, 12.9 years; range 10.0-17.5). Magnetic resonance (MR) imaging was conducted in 17 patients at 88 ± 52 months (range 12-157). During the same period, Simpson grade I removal (removal of the dural origin) was performed in 21 patients (follow-up, 89 ± 87 months; range 9-316). Radiological recurrence was defined as a visible tumor on a follow-up MR image, and clinical tumor recurrence was defined as the recurrence of symptoms.

RESULTS

At the final follow-up, neurological symptoms had improved in 16/20 patients and remained stable in 4/20. A recurrent tumor was detected in one patient due to increased back pain at 92 months postoperative, but the symptom was stable without surgery until the last follow-up (124 months). The radiological and clinical recurrence-free survival periods were 150 ± 7 months (95 % CI 136-163) and 204 ± 6 months (95 % CI 193-215), respectively. There was no recurrence after Simpson grade I removal, whereas neurological deterioration occurred in two patients after surgery.

CONCLUSIONS

Simpson grade II removal may be an alternative option if the risk of complications with Simpson grade I removal is expected to be high.

Symptomatic Spinal Cord Bending After Meningioma Resection: A Technical Case Report

Resection of intradural tumors is often followed by bending of the spinal cord within the surgical cave. This event is known to be innocuous. The authors report a case where the position assumed by the spinal cord at the end of surgery was associated with significant motor evoked potential decline. The patient, a 44-year-old woman with a meningioma of the craniocervical junction, underwent tumor resection aided by intraoperative neurophysiological monitoring. At the time of dural closure, the motor evoked potentials were completely lost on the left side and reduced on the right side. Intraoperative maneuvers showed that worsening was related to the spinal cord position. Motor evoked potentials were restored by tethering the cord posteriorly, back to its original site. This report underlines the usefulness of maintaining intraoperative monitoring until the end of surgery and provides a technical nuance to manage a rare complication.

Complication avoidance in the resection of spinal meningiomas

BACKGROUND

Surgical resection is considered the treatment of choice for spinal meningiomas and can be safe and effective; however, neurologic and surgical complications occur. This article reviews the factors that may predict susceptibility to this postoperative decline and addresses therapeutic choices, adjunctive therapies, and technologic applications that may help avoid complications.

METHODS

A literature search was conducted for articles related to spinal meningiomas addressing surgical treatment, adjuvant treatment, and technologic applications related to management and minimizing of complications.

RESULTS

There were 16 surgical series identified, comprising 1090 patients with median mortality of 1% (range, 0%-4%), nonneurologic surgical morbidity of 4% (range, 0%-24%), and permanent neurologic deterioration of 6% (range, 0%-21%). Common complications were cerebrospinal fluid leaks and fistulas, venous thromboembolic disease, myocardial infarction, and neurologic deterioration with either transient or permanent neurologic deficits. Predictive risk factors of neurologic decline included pathoanatomic features of lesion calcification, anterior dural attachment, infiltrative tumor, and tumoral adherence to the spinal cord and patient-specific factors of preoperative neurologic and advanced age.

CONCLUSIONS

Alongside surgery, selection of more direct approaches and use of adjuvant radiotherapy in patients with higher grade lesions and recurrent disease may lead to improved outcomes. New technologies, including microsurgical technique, intraoperative electrophysiologic monitoring, intraoperative ultrasound, and ultrasonic aspiration, may improve the safety and limit the complications of resection.

Spinal meningiomas. Personal experience and review of literature

Background: to present personal experience in the surgical management of spinal meningiomas, also the literature results review too.

Methods: 32 patients (4 men and 28 women) harboring spinal meningiomas who had undergone microsurgical resection were treated between 2002 and 2012 in our department. Clinical presentation, diagnosis, histological examination, microsurgical resection, functional outcome were evaluated, defining potential prognosis factors associated with these lesions.

Results: tumors site was intradural, extramedullary with different topography: the most common the thoracic region, posterolateral and antero-lateral. In all cases neurologic improvement was noted after operation, without instability, despite the extent of preoperative deficits. Transient motor deficits were observed in 2 thoracal anterior placed tumors without mortality. In 2 cases with semimaligne meningioma (6,25%) recurrence was noted at one and two years after first operation, initial diagnosis was transitional type meningioma.

Conclusion: benign spinal meningiomas should have always early diagnosis and microsurgical total resection for a good outcome. For semimalignant or even malignant cases, radiotherapy should be considered.

Minimally invasive surgery for benign intradural extramedullary spinal meningiomas: experience of a single institution in a cohort of elderly patients and review of the literature

Meningiomas of the spine are the most common benign intradural extramedullary lesions and account for 25%–46% of all spinal cord tumors in adults. The goal of treatment is complete surgical resection while preserving spinal stability. Usually, these lesions occur in the thoracic region and in middle-aged women. Clinical presentation is usually nonspecific and the symptoms could precede the diagnosis by several months to years, especially in older people, in whom associated age-related diseases can mask the tumor for a long time. We report a series of 30 patients, aged 70 years or more, harboring intradural extramedullary spinal meningiomas. No subjects had major contraindications to surgery. A minimally invasive approach ( hemilaminectomy and preservation of the outer dural layer) was used to remove the tumor, while preserving spinal stability and improving the watertight dural closure. We retrospectively compared the outcomes in these patients with those in a control group subjected to laminectomy or laminotomy with different dural management. In our experience, the minimally invasive approach allows the same chances of complete tumor removal, while providing a better postoperative course than in a control group.

Histological investigation of resected dura mater attached to spinal meningioma

STUDY DESIGN

Histological observational study of patients with spinal meningioma.

OBJECTIVE

To clarify the status of tumor cell invasion into the dura mater and to provide fundamental information for appropriate management of dural attachment.

SUMMARY OF BACKGROUND DATA

Histological appearance of the dura attached to spinal meningioma has not been sufficiently evaluated.

METHODS

Dura mater resected in a Simpson Grade 1 manner from 25 consecutive patients with spinal meningiomas (World Health Organization grade 1) was histologically observed to determine the status of tumor cell invasion. As no clear borders such as a tumor capsule between tumor and dura mater were observed, histological findings of the dura mater were classified into the following 3 categories: grade 1, no dural invasion, with only inflammation of the dura; grade 2: dural invasion below the zone between the inner and outer layers; and grade 3, dural invasion into or over the zone between the inner and outer layers (full-thickness invasion).

RESULTS

In our microscopic study, 19 of the 25 cases of spinal meningioma showed evidence of dural invasion and 15 cases showed full-thickness invasion.

CONCLUSION

This histological investigation of resected dura mater attached to spinal meningioma showed a high rate of full-thickness tumor invasion into the dura mater.