Fluorescein-guided removal of peripheral nerve sheath tumors: a preliminary analysis of 20 cases

OBJECTIVEBenign peripheral nerve sheath tumors (PNSTs) include mainly schwannomas—the most common tumors arising from peripheral nerves—and neurofibromas. Due to their origin, distinguishing between functional intact nerve and the fibers from whence the PNST arose may not always be easy to perform. The introduction of intraoperative tools to better visualize these tumors could be helpful in achieving a gross-total resection. In this study, the authors present a series of patients harboring PNST in which the surgery was performed under fluorescein guidance.METHODSBetween September 2018 and February 2019, 20 consecutive patients with a total of 25 suspected PNSTs underwent fluorescein-guided surgery performed under microscopic view with a dedicated filter integrated into the surgical microscope (YELLOW 560) and with intraoperative monitoring. All patients presented with a different degree of contrast enhancement at preoperative MRI. Fluorescein was intravenously injected after intubation at a dose of 1 mg/kg. Preoperative clinical and radiological data, intraoperative fluorescein characteristics, and postoperative neurological and radiological outcomes were collected and analyzed.RESULTSSix patients were affected by neurofibromatosis or schwannomatosis. There were 14 schwannomas, 8 neurofibromas, 1 myxoma, 1 reactive follicular hyperplasia, and 1 giant cell tumor of tendon sheath. No patient experienced worsening of neurological status after surgery. No side effects related to fluorescein injection were found in this series. Fluorescein allowed an optimal intraoperative distinction between tumor and surrounding nerves in 13 of 14 schwannomas and in all neurofibromas. In 6 neurofibromas and in 1 schwannoma, the final YELLOW 560 visualization showed the presence of small tumor remnants that were not visible under white-light illumination and that could be removed, obtaining a gross-total resection.CONCLUSIONSFluorescein was demonstrated to be a feasible, safe, and helpful intraoperative adjunct to better identify and distinguish PNSTs from intact functional nerves, with a possible impact on tumor resection, particularly in diffuse neurofibromas.

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Diffusion tensor tractography for the surgical management of peripheral nerve sheath tumors

Neurosurgical FOCUS ◽

10.3171/2015.6.focus15228 ◽

2015 ◽

Vol 39 (3) ◽

pp. E17 ◽

Cited By ~ 14

Author(s):

Manfred Schmidt ◽

Gregor Kasprian ◽

Gabriele Amann ◽

Dominik Duscher ◽

Oskar C. Aszmann

Keyword(s):

Peripheral Nerve ◽

Diffusion Tensor ◽

Tumor Resection ◽

Significant Risk ◽

Diffusion Tensor Tractography ◽

Surgical Removal ◽

Nerve Sheath Tumors ◽

Peripheral Nerve Sheath Tumors ◽

Nerve Sheath ◽

Mri Scans

OBJECT Peripheral nerve sheath tumors (PNSTs) are uncommon but bear a significant risk of malignancy. High-resolution MRI is the standard technique for characterizing PNSTs. However, planning the appropriate extent of resection and subsequent reconstructive strategies is highly dependent on the intraoperative findings because preoperative MRI evaluation can be insufficient. Diffusion tensor tractography (DTT) represents a recently developed advanced MRI technique that reveals the microstructure of tissues based on monitoring the random movement of water molecules. DTT has the potential to provide diagnostic insights beyond conventional MRI techniques due to its mapping of specific fibrillar nerve structures. Here, DTT was applied to evaluate PNSTs and to examine the usefulness of this method for the correct delineation of tumor and healthy nerve tissue and the value of this information in the preoperative planning of surgical interventions. METHODS In this prospective study, patients with the clinical symptoms of a PNST were investigated using DTT 3-Tesla MRI scans. Image data processing and tractography were performed using the FACT (fiber assessment by continuous tracking) algorithm and multiple-regions-of-interest approach. The surgical findings were then compared with the results of the DTT MRI scans. Preoperative fascicle visualization and the correlation with the intraoperative findings were graded. RESULTS In a 21-month period, 12 patients with PNSTs were investigated (7 female and 5 male patients with a mean age of 46.2 ± 19.2 years). All patients underwent surgical removal of the tumor. Schwannoma was the most common benign histopathological finding (n = 7), whereas 2 malignant lesions were detected. In 10 of 12 patients, good preoperative nerve fascicle visualization was achieved using DTT scans. In 9 of 10 patients with good preoperative fascicle visualization, good intraoperative correlation between the DTT scans and surgical anatomy was found. CONCLUSIONS DTT properly visualizes the peripheral nerve fascicles and their correct anatomical relation to PNST. DTT represents a promising new method for the preinterventional planning of nerve tumor resection.

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High-Definition 4K 3D Exoscope (ORBEYETM) in Peripheral Nerve Sheath Tumor Surgery: A Preliminary, Explorative, Pilot Study

Operative Neurosurgery ◽

10.1093/ons/opaa090 ◽

2020 ◽

Vol 19 (4) ◽

pp. 480-488

Author(s):

Ignazio G Vetrano ◽

Francesco Acerbi ◽

Jacopo Falco ◽

Antonio D’Ammando ◽

Grazia Devigili ◽

...

Keyword(s):

Peripheral Nerve ◽

Lower Limbs ◽

Gross Total Resection ◽

Nerve Sheath Tumor ◽

Tumor Surgery ◽

Total Resection ◽

Peripheral Nerve Sheath Tumors ◽

Advantages And Disadvantages ◽

Nerve Sheath ◽

Clinical Series

Abstract BACKGROUND Surgery for peripheral nerve sheath tumors aims to preserve functional fascicles achieving gross-total resection. Increasing the visualization of anatomic details helps to identify the different layers and the tumor-nerve interface. The traditional microscope can present some limitations in this type of surgery, such as its physical obstruction. OBJECTIVE To present a proof-of-concept study about exoscope-guided surgery for schwannomas of the lower limbs, to analyze the advantages and disadvantages of the 4K, high-quality, 3-dimensional (3D) imaging. METHODS We analyzed 2 consecutive surgical cases of suspected schwannomas of the lower limbs using the ORBEYE™ exoscope (Olympus). A standard operative microscope was also available in the operating room. All procedures were performed with neurophysiological monitoring, to identify functioning nerves and to localize the tumor capsule safest entry point. The cases are reported according to the PROCESS guidelines. RESULTS In both cases, we achieved a gross total resection of the schwannomas; the exoscope provided an excellent view of the anatomic details at tumor-nerve interface, as visible in intraoperative images and in the 3D-4K video supporting these findings. The surgeon's position was comfortable in both cases, although if the co-surgeon positioned himself in front of the first surgeon, the comfort was slightly reduced. The 4K monitor allowed a realistic, nontiring 3D vision for all the team. CONCLUSION The ORBEYETM, after an adequate learning curve, can represent a feasible and comfortable instrument for nerve tumor surgery, which is usually performed in a single horizontal plane. Further and wider clinical series are necessary to confirm this first impression.

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Role of resection of malignant peripheral nerve sheath tumors in patients with neurofibromatosis Type 1

Journal of Neurosurgery ◽

10.3171/2012.9.jns101610 ◽

2013 ◽

Vol 118 (1) ◽

pp. 142-148 ◽

Cited By ~ 32

Author(s):

Gavin P. Dunn ◽

Konstantinos Spiliopoulos ◽

Scott R. Plotkin ◽

Francis J. Hornicek ◽

David C. Harmon ◽

...

Keyword(s):

Multivariate Analysis ◽

Radiation Therapy ◽

Peripheral Nerve ◽

Neurofibromatosis Type ◽

Total Resection ◽

Nerve Sheath Tumors ◽

Peripheral Nerve Sheath Tumors ◽

Nerve Sheath

Object Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive sarcomas that often arise from major peripheral nerves. Approximately half of MPNSTs arise in patients with neurofibromatosis Type 1 (NF1) who, in comparison with patients without NF1, present at younger ages and with larger tumors that are commonly associated with extensive plexiform neurofibromas. These tumors therefore pose a particularly difficult treatment challenge because of the morbidity often associated with attempted gross-total resection (GTR). Here, the authors aim to examine what role the extent of resection and other covariates play in the long-term survival of patients with NF1 in the setting of MPNST. Methods The authors retrospectively reviewed the records of 23 adult patients with NF1 who underwent surgery for MPNSTs at their institution between 1991 and 2008. The primary end points of the study were mortality, local recurrence, and metastasis. Kaplan-Meier survival curves were evaluated for all patients. Differences for each of the primary end points were evaluated based on cause-specific covariates, which included tiered tumor size, tumor location, grade, resection margin status, postoperative weakness, and use of chemotherapy and radiation therapy. Multivariate analysis was performed using Cox proportional hazards models. Results Gross-total resection (p = 0.01) and surgical margin status (p = 0.034) had a statistically important role in prolonging overall survival in patients with NF1 by univariate analysis. When tumor size, location, grade, postoperative weakness, and radiation therapy were also taken into account using multivariate analysis, GTR continued to be a significant prognostic factor (p = 0.035). Conclusions These findings suggest that GTR offers significant long-term benefit on survival in patients with NF1. Benefit on survival occurred independently of all other covariates, suggesting that complete resection should be the principal goal of treatment in this patient population.

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Go for the Gold: A “Plane” and Simple Technique for Resecting Benign Peripheral Nerve Sheath Tumors

Operative Neurosurgery ◽

10.1093/ons/opz034 ◽

2019 ◽

Vol 18 (1) ◽

pp. 60-68 ◽

Cited By ~ 8

Author(s):

Jonathan J Stone ◽

Robert J Spinner

Keyword(s):

Peripheral Nerve ◽

Tumor Resection ◽

Layer By Layer ◽

Nerve Sheath Tumor ◽

Neurological Outcomes ◽

Nerve Sheath Tumors ◽

Peripheral Nerve Sheath Tumors ◽

Nerve Tumor ◽

Nerve Sheath ◽

Yellow Color

Abstract BACKGROUND Intraneural dissection is a useful technique for achieving gross total resection and preserving functional fascicles for peripheral nerve tumors. Finding the correct tissue plane is the critical step for safe successful enucleation. The authors hypothesized that the yellow color of benign nerve tumors can be used to identify surgical planes. OBJECTIVE To describe a technique to find the correct intraneural dissection plane based on a quantified yellow appearance during resection of benign peripheral nerve sheath tumors. METHODS Intraoperative photographs were reviewed to determine the percentage of yellow that tumors appeared at different phases of surgery. A technique was developed to quantitatively measure the amount of yellow using Photoshop. Previously published journal articles containing color images of peripheral nerve tumor resections were also analyzed for yellow tumor color. RESULTS There were 24 patients with suitable images to permit measurement of color for 3 steps of the procedure. The average percentages of yellow for tumor exposure, tumor resection, and removed specimen were 36.5%, 59.1%, and 80.4%, respectively (P < .001). Three publications were found that contained high-quality images of at least 2 phases of the surgery with average yellow content of 47.4% and 84% (P < .01). CONCLUSION The simple observation that a benign nerve sheath tumor is yellow in color can be used to guide surgical resection and achieve excellent outcomes. Intraneural dissection through the pseudocapsule should be pursued layer by layer until a yellow true capsule is found. By sparing functional nervous tissue within the pseudocapsule, this technique may lead to improved neurological outcomes.

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DIAGNOSIS AND MANAGEMENT OF INTRACRANIAL MALIGNANT PERIPHERAL NERVE SHEATH TUMORS

Neurosurgery ◽

10.1227/01.neu.0000318167.97966.f3 ◽

2008 ◽

Vol 62 (4) ◽

pp. 825-832 ◽

Cited By ~ 22

Author(s):

Liang Chen ◽

Ying Mao ◽

Hong Chen ◽

Liang-Fu Zhou

Keyword(s):

Peripheral Nerve ◽

Tumor Resection ◽

Residual Tumor ◽

The Other ◽

Postoperative Survival ◽

Rational Approach ◽

General Strategy ◽

Nerve Sheath Tumors ◽

Peripheral Nerve Sheath Tumors ◽

Nerve Sheath

Abstract OBJECTIVE Intracranial malignant peripheral nerve sheath tumors (MPNSTs) are rare and generally carry a poor prognosis. We have analyzed our experience with MPNSTs and conducted a review of the literature in an attempt to identify a rational approach to the management of these tumors. METHODS Eight patients underwent surgical treatment for intracranial MPNSTs during a 10-year period from 1996 to 2005. The general strategy was to perform complete resection whenever possible and to provide adjuvant radiotherapy for residual tumor. Chemotherapy was not used in this group. The clinical, radiological, operative, and pathological findings of the patients were reviewed retrospectively. RESULTS Six of the eight patients underwent primary operations; two of the eight patients had previously undergone other transcranial surgery operations. Total tumor resection was achieved in five patients. At this time, two have been recurrence-free for 3.5 and 5 years, respectively, and the other three patients had a mean postoperative survival of 7 months. There was one case of near total (>90%) and two cases of partial (<90%) tumor removal; the postoperative survival rate was 4, 4, and 2 months, respectively. Only two patients in our group accepted radiotherapy after surgery; one survived only 4 months and the other has been recurrence-free for 5 years. CONCLUSION MPNSTs are fast-growing, invasive tumors with rather unsatisfactory outcomes. Total surgical resection seems to be the most effective therapeutic method, and radiotherapy may play a role in local control.

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