Minimally invasive microsurgical resection of primary, intradural spinal tumours using a tubular retraction system

Spinal intradural extramedullary tumors: microscopic keyhole resection with the focus on intraoperative neurophysiological monitoring and long-term outcome

OBJECTIVE

Spinal schwannomas (SS) and spinal meningiomas (SM) account for most intradural extramedullary (IDEM) tumors. These tumors are usually benign lesions, which generally respond favorably to surgical excision. Few studies up to now tried to determine the long-term outcome after minimally invasive surgery (MIS) with multimodal intraoperative neurophysiological monitoring (IONM) for IDEM tumors. The aim of this study was to present one of the largest case series with special regard to IONM findings and long-term outcome after MIS-keyhole surgery with a tubular retractor system.

METHODS

Between January 2013 and August 2018, 87 patients with IDEM tumors who underwent tumor removal surgery via MIS-keyhole approach under multimodal IONM were retrospectively reviewed. The neurological status was assessed using a modified McCormick grading scale pre- and postoperatively. Multimodal IONM consisted of motor evoked potentials (MEP), somatosensory evoked potentials (SEP), and electromyography (EMG). Both short-term and long-term clinical evaluations as well as patients' medical files were retrospectively analyzed.

RESULTS

Surgeries were performed for resection of SS in 49 patients and SM in 38 patients. Tumor locations were cervical in 16.1%, thoracic in 48.3%, thoracolumbar in 4.6%, lumbar 31%. Critical IONM changes were detected in 9 operations (10.3%) in which there were 2 SEPs, 5 MEPs, and 2 EMG events. Three IONM changes (2 MEPs, 1 EMG) were turned out to be transient change in nature since they were resolved in a short time when immediate corrective actions were initiated. Six patients with permanent IONM changes (2SEPs, 3MEPs, 1EMG event), all deficits had resolved during hospitalization or on short -term follow-up evaluation. Sensitivity, specificity, and positive and negative predicted values of IONM were 100, 96, 67, and 100%, respectively. Gross total resection rate was 100%, and a stable or improved McCormick grade exhibited in all patients. No tumor recurrence and no spinal instability were found in the long-term follow-up evaluation (mean 5.2 ± 2.9 years postoperatively). Overall, 94% of patients were either satisfied or very satisfied with their operation, and 93% patients reported excellent or good general clinical outcome according to Odom's criteria.

CONCLUSION

MIS-keyhole surgery with multimodal IONM for IDEM tumors enables a high level of satisfaction and a satisfying long-term clinical and surgical outcome.

Pure endoscopic minimally invasive surgery with a non‑expandable tubular retractor for intradural extramedullary spinal tumors

Minimally invasive spinal surgery (MISS) for intradural extramedullary (IDEM) spinal tumors is a safe and effective surgical strategy. Currently, various tubular retractors are widely used in the MISS of IDEM spinal tumors, primarily relying on microscopic visualization. To the best of the authors' knowledge, there is no report of pure endoscopic surgery with parallel non-expandable tubular retractors for IDEM spinal lesions. The present study reports a case series of IDEM spinal tumors that were treated via pure endoscopic MISS with a parallel non-expandable tubular retractor. The extent of tumor resection was evaluated by comparing preoperative and postoperative magnetic resonance imaging (MRI). The initial and follow-up clinical conditions were assessed according to the visual analog scale for pain and the modified McCormick scale for neurological status. Postoperative MRI demonstrated that all cases had achieved a gross total resection. After the operation, the clinical symptoms of all patients were significantly improved and there were no serious postoperative complications. At the initial follow-up, the pain experienced by the patients was significantly reduced or had even disappeared, and the neurological deficit was improved by at least one grade on the modified McCormick scale. The present report indicates that pure endoscopic MISS with a parallel non-expandable tubular retractor may be an effective and safe surgical strategy for IDEM spinal tumor resection.

Surgical treatment and outcomes of intramedullary tumors by minimally invasive approach: Answer

The surgical outcomes which evaluated in studies depend on preoperative condition, demographic data of patients, surgical approaches or treatment and local factors. Author argues that the neurological deterioration rate 4,2% which is reported in our study is marvelous and he exemplifies the other studies in literature. Neurosurgeons know that the clinical studies in literature do not compare only their results. Authors compare and evaluate studies with preoperative demographic data, surgical approach, local factors or others between their results. Therefore this detail explains paralogism of the author. The neurological deterioration rate is reported as smaller or similar in our study to the contrary of others due to all the preoperative demographical data were evaluated with others. We suppose the author alludes that the neurological deterioration rate is marvelous since he does not compare all of the demographical data in these clinical studies.

Minimally Invasive Resection of Spinal Tumors with Tubular Retractor: Case Series, Surgical Technique, and Outcome

BACKGROUND

Traditional laminectomy for excision of spinal tumors involves extensive dissection of the midline spinous ligaments, greater blood loss, and risk of delayed segmental instability. The minimally invasive technique of spinal tumor resection using tubular retractors can achieve safe and complete tumor resection while preserving the structural and functional integrity. The authors present their experience of minimally invasive spinal surgery for spinal tumors in this case series.

METHODS

The authors retrospectively reviewed 41 consecutive spinal tumor cases operated by the MISS-Key Hole technique using the tubular retractor system at Sree Utharadom Thirunal Hospital, Kerala, India between January 2015 and January 2020. Preoperative clinical findings, surgical technique, operative statistics, complications, and patient outcomes were analyzed in detail.

RESULTS

We could successfully achieve gross total resection in 39 cases (95.12%) and subtotal resection in 2 cases. There were 4 cervical, 1 craniovertebral junction, 20 thoracic, 14 lumbar, and 2 sacral lesions, of which 4 were extradural, 1 extradural foraminal, 33 intradural, and 3 dumbbell lesions. The Modified McCormick Scale at 12 weeks had improved by 1-2 scales in all but 2 patients. There was no cerebrospinal fluid leak, pseudomeningocele, or infection in our series.

CONCLUSIONS

This series demonstrates the feasibility, safety and effectiveness of the keyhole approach for excision of intradural and extradural spinal tumors extending up to 2 levels. Careful case selection, good preoperative planning, meticulous microsurgical resection, and watertight dural closure are crucial for successful outcome. Early mobilization, less blood loss, and avoidance of delayed instability are the advantages of minimally invasive spinal surgery when compared with open surgery.

Surgical treatment and outcomes of intramedullary tumors by minimally invasive approach

Intramedullary tumors are uncommon neoplasms which, without treatment, can cause neurologic morbidity or mortality. The goal of the treatment is complete surgical resection with a minimally invasive approach while preserving neurological status and also spinal stability. Out of 1972 patients with tumors of the spinal canal treated between 1994 and 2017, 168 intramedullary tumors of 417 intradural tumors have been presented. All patients had undergone one surgical resection. The mean age is 43 ± 12 years (range 11-67 years). Tumors were subdivided into 4 groups: cervically located-tumors (n = 43), cervicothoracic-region-tumors (n = 32), thoracic-region-tumors (n = 57), and lumbosacral-region-tumors (n = 36). The mean follow-up time was 37 ± 29 months. Gross-total resection rate was higher in cervical located intramedullary tumors compared to the thoracic intramedullary tumors. Cervical intramedullary tumors showed better postoperative functional outcome than the thoracic intramedullary lesions. In intramedullary tumors, extending more than 3 spinal segments, postoperative worsening was significantly increased. A minimally invasive approach (the bilateral decompression via unilateral hemilaminectomy) was used to remove the tumor while preserving spinal stability. Perioperative permanent morbidity was very low. Intramedullary tumors should be surgically treated as soon as neurological symptoms appear. Patients with thoracic intramedullary tumors and tumor extension of more than three segments were at a higher risk for permanent morbidity. The minimally invasive approach allowed complete removal of the intramedullary tumors, and adequate preservation of vertebral stability while providing a good postoperative course.

Spinal meningiomas: Treatment outcome and long-term follow-up

BACKGROUND

Spinal intradural tumors can be classified as intradural extramedullary or intramedullary tumors. Spinal meningiomas are among the most frequent intradural, extramedullary tumors (IDEMs), representing 12 % of all meningiomas and 25-45 % of all intradural spinal tumors.

OBJECTIVE

To evaluate postoperative outcome, defined by mortality, tumor recurrence and modified Rankin Scale in patients with spinal meningiomas. Furthermore, to identify factors related to these outcome measures and define possible prognosticators.

METHODS

A large single center retrospective analysis of 166 consecutive spinal meningioma patients during a 29-year period (1989-2018).

RESULTS

Female to male ratio was 5.15 to 1. Of all 166 resected tumors, 159 were WHO grade I and seven were WHO grade II. Histopathologically, the psammomatous type was most common (42.8 %). The thoracic region was the most frequent location (71.1 %), followed by cervical and lumbar locations. A complete resection (Simpson I-III) was achieved in 88.7 %. In 12 cases (7.2 %) recurrences of a spinal meningioma occurred after an interval of 0.70-13.78 years. Postoperative complications consisted of CSF leakage and wound healing problems. Three patients died of direct postoperative complications (1.8 %), nine patients died in follow-up due to unrelated causes. Post-operative complications were related to the overall outcome (p = 0.029). Clinical outcome showed improvement in 117 patients out of 148 (79.1 %) according to modified Rankin Scale; 24 patients remained stable and 7 patients deteriorated. Patients with pre-existing bladder/bowel problems and incomplete resections had higher chance of recurrences. Younger patients also had a higher recurrence rate. Follow-up ranged from 0 to 23 years, median of 0.77 years, most were discontinued after 2 years.

CONCLUSIONS

The primary treatment of spinal meningiomas remains surgery. Complete resection of spinal meningiomas is achieved in most of the cases, however preserving and improving neurological status has priority over complete tumor resection. Morbidity and mortality is relatively low. Longer follow-up periods are recommended, since recurrences can occur after 10-15 years.

Minimally invasive repair of a pseudomeningocele caused by a sheared intrathecal catheter following implantation of a drug delivery system

Background:

Shearing of an intrathecal catheter during implantation of a drug delivery system is an underreported complication that can be challenging to manage.

Case Description:

A 53-year-old man with refractory cancer pain had an intrathecal pump system implanted. The procedure was complicated with catheter shear and retention in the intrathecal space. A second catheter was successfully placed but formation of a painful pseudomeningocele and ineffective pain relief complicated the outcome. A minimally invasive approach through a tubular retractor was employed to access the spinal canal via a laminotomy, the sheared catheter was removed and the dural defect repaired. Complete resolution of the pseudomeningocele and efficient pain control were observed at follow-up.

Conclusion:

Minimally invasive approach to the spine is demonstrated as a safe and effective alternative in this case of retained catheter induced cerebrospinal fluid (CSF) leak.

Minimally Invasive Microsurgical Resection of Primary, Intradural Spinal Tumors is Feasible and Safe: A Consecutive Series of 83 Patients

BACKGROUND

To date, the traditional approach to intraspinal tumors has been open laminectomy or laminoplasty followed by microsurgical tumor resection. Recently, however, minimally invasive approaches have been attempted by some.

OBJECTIVE

To investigate the feasibility and safety of minimally invasive surgery (MIS) for primary intradural spinal tumors.

METHODS

Medical charts of 83 consecutive patients treated with MIS for intradural spinal tumors were reviewed. Patients were followed up during the study year, 2015, by either routine history/physical examination or by telephone consultation, with a focus on tumor status and surgery-related complications.

RESULTS

Mean age at surgery was 53.7 yr and 52% were female. There were 49 schwannomas, 18 meningeomas, 10 ependymomas, 2 hemangioblastomas, 1 neurofibroma, 1 paraganglioma, 1 epidermoid cyst, and 1 hemangiopericytoma. The surgical mortality was 0%. In 87% of cases, gross total resection was achieved. The complication rate was 11%, including 2 cerebrospinal fluid leakages, 1 asymptomatic pseudomeningocele, 2 superficial surgical site infections, 1 sinus vein thrombosis, and 4 cases of neurological deterioration. There were no postoperative hematomas, and no cases of deep vein thrombosis or pulmonary embolism. Ninety-three percent of patients were ambulatory and able to work at the time of follow-up.

CONCLUSION

This study both demonstrates that it is feasible and safe to remove select, primary intradural spinal tumors using MIS, and augments the previous literature in favor of MIS for these tumors.

Unilateral Hemilaminectomy for Intradural Lesions

OBJECTIVE

Unilateral hemilaminectomy (UHIL), an alternative surgical approach to intradural lesions, involves a unilateral approach to meningeal opening that provides an adequate window for tumor extraction while leaving most of the vertebral structures intact. The techniques and results of a modified hemilaminectomy technique with spinal endoscopy is discussed and limited unilateral hemilaminectomy for intradural tumors (UHIT) evaluated prospectively.

METHODS

Relevant clinical variables, operative reports, histological findings, pre- and post-operative imaging, and follow-up data for 11 consecutive patients (five males, six females; mean age 63.36 ± 20.69 years) who underwent modified hemilaminectomy over a 3 year time period were analyzed. Contrast-enhanced MRI was used to demonstrate the side, size and location of the suspected tumor or intradural lesion and CT to evaluate the bone anatomy. Post-operative MRI and CT allowed evaluation of anatomy following resection.

RESULTS

Lesions included meningiomas (n = 2), neuromas (n = 3), and metastases, cysts or gliomas (n = 6). Pre-operative indications in order of incidence included cord compression, claudication, lower back pain, radiculopathy, paraplegia, weakness, incontinence, and generalized neuro-deterioration. There were no major complications, and no spinal deformity or instability at final follow up (mean, 13 months; range, 3-36 months).

CONCLUSION

Our data suggest that there is a place for the UHIT approach. This minimally invasive approach is useful for resecting all intradural tumors. UHIL is a useful minimally invasive technique for resecting intradural spinal tumors with maximal preservation of musculoligamentous attachments and posterior bony elements and should be considered an improvement on currently employed techniques.

Perioperative Cost Analysis of Minimally Invasive vs Open Resection of Intradural Extramedullary Spinal Cord Tumors

BACKGROUND:

Minimally invasive spinal surgery (MIS) has emerged as a clinically effective tool but its cost-effectiveness remains unclear. No studies have compared MIS vs open surgical techniques for the treatment of intradural extramedullary (IDEM) tumors.

OBJECTIVE:

To analyze and compare open and MIS techniques for resection of IDEM tumors, with focus on perioperative costs.

METHODS:

Retrospective analysis of a prospectively collected database including 35 IDEM patients (18 open, 17 MIS). Perioperative data, hospital costs, and hospital and physician charges for in-hospital services associated with the index surgical procedure and readmissions within 90 days were compared.

RESULTS:

Mean estimated blood loss, operative time, preoperative hospital charges, and physician fees were similar between open and MIS techniques. Patient and tumor characteristics were similar between groups. MIS cases were associated with shorter intensive care unit and floor stay. There were 3 complications in the open group, requiring 2 readmissions and 1 reoperation. Hospital costs ($21 307.80 open, $15 015.20 MIS, P < .01), and postoperative ($75 383.48 open, $56 006.88 MIS, P < .01) and total charges ($100 779.38 open, $76 100.92 MIS, P < .01) were significantly lower in the MIS group. There were no tumor recurrences in either group. All patients except for one in the open group maintained or improved their Nurick score.

CONCLUSION:

Both MIS and open techniques were able to adequately treat IDEM tumors. Reductions in complication rate and intensive care unit and hospital stay led to a decrease in hospital costs of almost 30% in the MIS group. MIS resection of IDEM tumors is not only an effective and safe option, but allows faster hospital discharge and significant cost savings.

Surgical management of Giant Lumbar Extradural Schwannoma: Report of 3 cases

Standard surgical approach for extradural paraspinal tumours has been through a unilateral facetectomy, inter-transverse or retroperitoneal approach. Some of these approaches destabilise the spine and consequently require a fusion procedure. Access to these tumours through a minimal access route can decrease tissue damage, fasten post-operative recovery and obviate the need for a concomitant fusion procedure. However, proper case selection and adequate pre-operative planning are important in choosing cases for a minimally invasive approach. We discuss three cases of giant extradural, paraspinal schwannomas. One case that was associated with listhesis along with the tumour situated more anteriorly and embedded in the psoas muscle was managed by lateral retroperitoneal route with simultaneous interbody graft followed by posterior interspinous stabilising device. The other two cases were managed by minimal access route using a 22mm fixed tubular retractor, one by a paramedian approach and one by far lateral approach. The technique and merits of the procedure are discussed.