Management of Extramedullary Intradural Spinal Tumors: The Impact of Clinical Status, Intraoperative Neurophysiological Monitoring and Surgical Approach on Outcomes in a 12-Year Double-Center Experience.

Fabio Cofano,Fulvio Massaro,Carola Vera Junemann,Pietro Zeppa,Alessandro Ducati,Carlotta Giambra,Marco Mammi,Diego Garbossa,Fulvio Tartara,Matteo Monticelli,Francesco Zenga,Paolo Costa,Antonio Melcarne,Giuseppe Di Perna,Andrea Bianconi

doi:10.3389/fneur.2020.598619

Abstract

Objective: Intradural Extramedullary (IDEM) tumors are usually treated with surgical excision. The aim of this study was to investigate the impact on clinical outcomes of pre-surgical clinical conditions, intraoperative neurophysiological monitoring (IONM), surgical access to the spinal canal, histology, degree of resection and intra/postoperative complications.Methods: This is a retrospective observational study analyzing data of patients suffering from IDEM tumors who underwent surgical treatment over a 12 year period in a double-center experience. Data were extracted from a prospectively maintained database and included: sex, age at diagnosis, clinical status according to the modified McCormick Scale (Grades I-V) at admission, discharge, and follow-up, tumor histology, type of surgical access to the spinal canal (bilateral laminectomy vs. monolateral laminectomy vs. laminoplasty), degree of surgical removal, use and type of IONM, occurrence and type of intraoperative complications, use of Ultrasonic Aspirator (CUSA), radiological follow-up.Results: A total number of 249 patients was included with a mean follow-up of 48.3 months. Gross total resection was achieved in 210 patients (84.3%) mostly in Schwannomas (45.2%) and Meningiomas (40.4%). IONM was performed in 162 procedures (65%) and D-wave was recorded in 64.2% of all cervical and thoracic locations (99 patients). The linear regression diagram for McCormick grades before and after surgery (follow-up) showed a correlation between preoperative and postoperative clinical status. A statistically significant correlation was found between absence of worsening of clinical condition at follow-up and use of IONM at follow-up (p = 0.01) but not at discharge. No associations were found between the choice of surgical approach and the extent of resection (p = 0.79), the presence of recurrence or residual tumor (p = 0.14) or CSF leakage (p = 0.25). The extent of resection was not associated with the use of IONM (p = 0.91) or CUSA (p = 0.19).Conclusion: A reliable prediction of clinical improvement could be made based on pre-operative clinical status. The use of IONM resulted in better clinical outcomes at follow-up (not at discharge), but no associations were found with the extent of resection. The use of minimally invasive approaches such as monolateral laminectomy showed to be effective and not associated with worse outcomes or increased complications.

Highlights

Intradural extramedullary (IDEM) tumors are generally benign neoplasms arising in the spinal canal, accounting for about twothirds of primary spinal tumors and 15% of tumors affecting the Central Nervous System [1,2,3]
Data were extracted from a prospectively maintained database collected during patient hospitalization and follow-up, and included: sex, age at diagnosis, clinical status according to the modified McCormick Scale (Grades I-V) (Table 1) [28] at admission, discharge, and follow-up, tumor histology and grade, type of surgical access to the spinal canal, degree of surgical removal, use and type of Intraoperative neurophysiological monitoring (IONM), occurrence and type of intraoperative complications, use of Cavitational Ultrasonic Surgical Aspiration (CUSA), the presence of a residual tumor or recurrence at followup through magnetic resonance imaging (MRI)
Bilateral laminectomy was the preferred approach in 148 cases (59.5%), while minimally-invasive monolateral laminectomy was performed in 78 cases (31.3%)

Summary

Introduction

Intradural extramedullary (IDEM) tumors are generally benign neoplasms arising in the spinal canal, accounting for about twothirds of primary spinal tumors and 15% of tumors affecting the Central Nervous System [1,2,3] Owing to their relative rarity, no specific treatment guidelines are currently available, radical excision surgery is considered to be the treatment of choice [4, 5]. The growing interest for IONM in spinal surgery has been recently described by Sala, which documented the increasing number of publications and scientific meetings dedicated to this topic through the last years [16] To strengthen this aspect, the importance of IONM in spinal surgery was corroborated and enhanced later by Class I evidence in the available Literature [17, 18]. The use of mono lateral laminectomy, and the use of technological tools such as the Cavitational Ultrasonic Surgical Aspiration (CUSA) should need for further investigations in order to add relevant data and report surgical experiences [13, 26, 27]

Methods

Results

Discussion

Conclusion