Benign Intradural and Paraspinal Nerve Sheath Tumors: Advanced Surgical Techniques

Minimally Invasive Resection of a Foraminal Lumbar Root Schwannoma

Background and Importance

This video article reports a rare case of a right L5/S1 foraminal root schwannoma that presents the natural course of the disease, imaging findings, treatment protocol, operative procedure, and highlights some of the possible surgical complications.

Clinical Presentation

Magnetic resonance imaging (MRI) revealed an intradural, extramedullary, well-enhanced mass at the right L5/S1 level. The operative procedure involved a right minimal L5/S1 laminotomy/foraminotomy posteriorly to open the right L5 root. The facet joints were preserved to prevent spinal instability. The tumor was located along the root after opening the right L5/S1 foramen. Intraoperative electromyography (IOM) was conducted to detect any nerve injury in the patient. After opening the dura, the tumor was carefully separated from the normal root nerve under IOM monitoring. The mass was removed piece-by-piece using mini-forceps.

Conclusion

Histopathological examination confirmed the diagnosis of a schwannoma. The patient recovered without incident after surgery with minimal soreness and numbness in the right leg.

Understanding a mass in the paraspinal region: an anatomical approach

The paraspinal region encompasses all tissues around the spine. The regional anatomy is complex and includes the paraspinal muscles, spinal nerves, sympathetic chains, Batson's venous plexus and a rich arterial network. A wide variety of pathologies can occur in the paraspinal region, originating either from paraspinal soft tissues or the vertebral column. The most common paraspinal benign neoplasms include lipomas, fibroblastic tumours and benign peripheral nerve sheath tumours. Tumour-like masses such as haematomas, extramedullary haematopoiesis or abscesses should be considered in patients with suggestive medical histories. Malignant neoplasms are less frequent than benign processes and include liposarcomas and undifferentiated sarcomas. Secondary and primary spinal tumours may present as midline expansile soft tissue masses invading the adjacent paraspinal region. Knowledge of the anatomy of the paraspinal region is of major importance since it allows understanding of the complex locoregional tumour spread that can occur via many adipose corridors, haematogenous pathways and direct contact. Paraspinal tumours can extend into other anatomical regions, such as the retroperitoneum, pleura, posterior mediastinum, intercostal space or extradural neural axis compartment. Imaging plays a crucial role in formulating a hypothesis regarding the aetiology of the mass and tumour staging, which informs preoperative planning. Understanding the complex relationship between the different elements and the imaging features of common paraspinal masses is fundamental to achieving a correct diagnosis and adequate patient management. This review gives an overview of the anatomy of the paraspinal region and describes imaging features of the main tumours and tumour-like lesions that occur in the region.

Tubular minimally invasive resection of McCormick type II paraspinal schwannoma: preliminary experience

PURPOSE

Complete removal of paraspinal schwannomas is generally required for full patient recovery. However, traditional open approaches to surgery are often extensive and may lead to more postoperative complications. Herein, we present our preliminary experience with tubular minimally invasive resection of McCormick type II paraspinal schwannomas and describe the technique by specifically reviewing two patient cases.

MATERIALS AND METHODS

Type of study: Retrospective: Level of evidence: Level III: A total of 15 patients (six men; nine women; median age, 45 years) who underwent minimally invasive resection of McCormick type II paraspinal schwannomas were retrospectively analysed. Preoperative characteristics, including age, location of tumour, Visual Analog Scale score, Modified McCormick Scale score, and intraoperative findings and complications were analysed. Furthermore, postoperative outcomes using imaging, such as magnetic resonance imaging (MRI) and thin-slice computed tomography, and postoperative neural status using the Modified McCormick and Visual Analog Scales were also assessed.

RESULTS

The mean operation time was 134.72 ± 34.21 min. The estimated mean blood loss and mean hospital stay were 25.33 ± 17.27 ml and 7.67 ± 1.88 days, respectively. Regarding complications, one of the patients had a local wound infection, which improved after antibiotic treatment. The total resection in all cases was verified using postoperative MRI.

CONCLUSION

The tubular minimally invasive approach is a feasible technique for the total resection of McCormick type II paraspinal schwannomas. Using this technique, surgeons can resect paraspinal schwannomas while maintaining spinal stability.

Sacrifice of Involved Nerve Root during Surgical Resection of Foraminal and/or Dumbbell Spinal Neurinomas

Even if usually needed to achieve the gross total resection (GTR) of spinal benign nerve sheath tumors (NSTs), nerve root sacrifice remains controversial regarding the risk of neurological deficit. For foraminal NSTs, we hypothesize that the involved root is poorly functional and thus can be safely sacrificed. All spinal benign NSTs with foraminal extension that underwent surgery from 2013 to 2021 were reviewed. The impacts of preoperative clinical status and patient and tumor characteristics on long-term outcomes were analyzed. Twenty-six patients were included, with a mean follow-up (FU) of 22.4 months. Functional motor roots (C5-T1, L3-S1) were involved in 14 cases. The involved nerve root was routinely sacrificed during surgery and GTR was obtained in 84.6% of cases. In the functional root subgroup, for patients with a pre-existing deficit (n = 5/14), neurological aggravation persisted in one case at last FU (n = 1/5), whereas for those with no preop deficit (n = 9/14), a postoperative deficit persisted in one patient only (n = 1/9). Preoperative radicular pain was the only characteristic significantly associated with an immediate postoperative motor deficit (p = 0.03). The sacrifice of an involved nerve root in foraminal NSTs seems to represent a reasonable and relevant option to resect these tumors, permitting one to achieve tumor resection in an oncologic fashion with a high rate of GTR.

Feasibility and efficacy of spinal microtubular technique for resection of lumbar dumbbell-shaped tumors

Objective

Minimally invasive surgical resection of lumbar dumbbell-shaped tumors is rarely reported. We retrospectively collected clinical data of lumbar dumbbell-shaped tumors treated with the spinal microtubular technique to evaluate the feasibility, complications and efficacy of the surgical methods.

Methods

From September 2013 to August 2021, clinical data of patients with lumbar dumbbell-shaped tumors that underwent paravertebral approach and micro-tubular tumorectomy (PAMT) were collected; neurological function was assessed using the pain visual analog scale (VAS) and the Japanese Orthopaedic Association (JOA) score.

Results

A total of 46 patients that underwent PAMT were included in this study. In all patients, total resection of the tumor was performed at one stage (100%). The median follow-up period was 27.5 months (P25, P75: 16.5- 57 months). Symptoms such as pain or lower extremity weakness were significantly relieved in 46 patients. The postoperative VAS score and JOA score were significantly higher compared with preoperative scores (p <0.001), and the patients had no tumor recurrence or spinal instability. According to the Eden classification, there were 7 cases of type I, 8 cases of type II, 15 cases of type III, and 16 cases of type IV. In the comparison of the improvement of VAS score at 12 months after PAMT, there were significant differences among different types of tumors (H =15.756, p =0.001); type I was better than type III (Z =2.768, p =0.029) and type IV (Z =2.763, p =0.029), and type II was also better than type III (Z =2.679, p =0.037) and type IV (Z =2.708, p =0.034). With respect to estimated blood loss (Z =-3.041, p =0.013) and postoperative hospital stays (Z =-3.003, p =0.014), type IV was less than type III; and type IV was also less than type II about operation time (Z =-2.653, p =0.040).

Conclusion

In small lumbar dumbbell-shaped tumors, PAMT is indicated for Eden types I-IV and different pathological types of tumors, and can achieve complete resection of the tumor (GTR) in one stage with a good prognosis.

Do Tumour Size, Type and Localisation Affect Resection Rate in Patients with Spinal Schwannoma?

Background and Objectives: Spinal schwannomas are benign tumours that can present with various symptoms such as pain, radiculopathy and neurological deficit. Gross total resection (GTR) is of key importance for local recurrence. The aim of this study is to describe the clinical characteristics, resection rate, clinical outcome, as well as tumour recurrence, in patients with non-syndromic spinal schwannomas and to clarify which factors affect the resection rate. Materials and Methods: Patients with non-syndromic spinal schwannomas that underwent surgical resection between January 2009 and December 2018 at a single institution were included. Demographic parameters, clinical symptoms, tumour localisation and size, surgical approach and complications were noted. Factors influencing the extent of resection, the surgeon’s decision regarding the approach and the occurrence of new postoperative deficits were evaluated. Results: Fifty patients (18 females) were included. The most common presenting symptom was radiculopathy (88%). The lumbar spine was the most commonly affected site (58%). Laminotomy (72%) was the preferred surgical approach overall and specifically for exclusively intraspinal schwannomas (p = 0.02). GTR was achieved in 76.0% (n = 38). In multivariate analysis, only tumour localisation within the spinal canal (p = 0.014) independently predicted GTR, whereas the type of approach (p = 0.50) and tumour volume (p = 0.072) did not. New postoperative persisting deficits could not be predicted by any factor, including the use and alteration of intraoperative neuromonitoring. Recurrence was observed in four cases (8%) and was significantly higher in cases with STR (p = 0.04). Conclusions: In this retrospective study, GTR was solely predicted by tumour localisation within the spinal canal. The decision regarding the utilisation of different surgical approaches was solely influenced by the same factor. No factor could predict new persisting deficits. Tumour recurrence was higher in STR.

Minimally Invasive Posterolateral Approach for Surgical Resection of Dumbbell Tumors of the Lumbar Spine

Minimally invasive spine surgery (MISS) has many advantages over traditional open surgical procedures that can be conducted for the therapy of different diseases of the spine. MISS provide many prospective advantages such as, for example, small incisions, less damage to soft tissues, early activation of patients, and a shorter postoperative hospital stay. The aim of the study was to evaluate institutional experience with Dumbbell tumors and metastatic lesions of the lumbar spine and compare it with traditional open surgical resection of this type of tumors. Fourteen patients underwent the surgery with minimally invasive posterolateral approach in experimental group, and 10 patients of the control group were operated using the traditional open surgery procedure at the Department of spinal neurosurgery and pathology of peripheral nervous system of JSC “National Center for Neurosurgery.” The intraoperative neuro monitoring system (ISIS IOM System Compact, Inomed, Germany) was used in both groups. Sensory and motor evoked potentials were intraoperatively recorded. The present study was approved by the local Ethics Committee of the National Center for Neurosurgery. Patients signed informed consent before the surgical procedure. The experimental group included 14 patients, that underwent the surgery during the period from January 2020 till March 2021. And the control group included 10 patients that was operated from January 2018 to December 2019. The results of the treatment in both groups were assessed according to the generally accepted visual analog scale (VAS) and the Oswestry scales before, on the third day, and 3 months after the surgery. In experimental group, average reduction of the pain syndrome of 3.36 points (from 3 to 0 points) was observed in patients postoperatively according to the VAS 3 days, and of 4.0 points (from 2 to 0 points) 3 months after surgical procedures. Improvement by 23.86% (36–16%) was also observed using the Oswestry Disease Index (ODI) 3 days after the surgery, and then reduced to 21.00% (16–34%) in average in 3 months. All patients were revived 3 h after transfer to the specialist department. The average stay in the hospital was 6.5 (9–4) days in both groups. In control group, average reduction of the pain syndrome of 2.60 points (from 4 to 1 points) was observed postoperatively according to the VAS 3 days after the operation, and of 3.9 points (from 2 to 0 points) 3 months after the surgery. The ODI of patients was also improved by an average of 35.40% (50–20%) 3 days after the surgical procedure, and reduced to 24.20% (16–32%) in average 3 months after the surgery.

Efficacy of One-stage Paravertebral Approach using a Micro-Tubular Technique in Treating Thoracic Dumbbell Tumors

OBJECTIVE

The aim of the present study was to investigate the feasibility and efficacy of one-stage surgical resection of thoracic dumbbell tumors using a paravertebral approach and a micro-tubular technique.

METHODS

Clinical data of thoracic dumbbell tumors resected using a paravertebral approach and a micro-tubular technique (14 mm, non-expandable type) in the Department of Neurosurgery at our hospital from July 2014 to July 2019 were retrospectively analyzed. Tumors were found between T1 and T12 vertebrae. Operation time, blood loss, hospitalization, recovery of neurological function, complications, the Japanese Orthopaedic Association (JOA) score, and the visual analogue scale (VAS) score were used to evaluate clinical efficacy.

RESULTS

In all 31 cases, tumors were completely resected in one operation, with a mean blood loss of 53.23 ± 33.08 mL (20-150 mL) and a mean operation time of 95.16 ± 20.31 min (60-180 min). According to the Eden classification, there were four type II cases, 16 type III cases, and 11 type IV cases. The incidence of tumors in the lower thoracic segment (T8-T12) was 51.6% (16/31 cases), while the incidences in the upper thoracic segment (T1-T4) and middle segment (T5-T8) were 25.8% (8/31 cases) and 22.6% (7/31 cases), respectively. Pathological diagnoses were schwannoma (n = 22), gangliocytoma (n = 4), metastatic tumor (n = 2), neurofibroma (n = 1), granuloma (n = 1), and lipoma (n = 1). After surgery, symptoms were relieved in all patients. VAS and JOA scores significantly improved (P < 0.001). There was no pleural or lung injury, and there were no complications, such as cerebrospinal fluid leakage. The average follow-up duration was 29 months (13-59 months), during which time no tumor recurrence or spinal instability occurred. The group of Eden type II tumors had lower JOA scores at 12 months postoperatively, longer operation times, and more estimated blood loss compared with other groups (P < 0.05). There were no significant influences on VAS scores at 12 months postoperatively and postoperative hospital stay from the different types of tumors.

CONCLUSION

The paravertebral approach with a micro-tubular technique is a safe and effective minimally invasive surgical approach for thoracic dumbbell tumors that allows one-stage tumor resection using a single incision. Using this approach significantly reduces intraoperative blood loss and postoperative complications, shortens hospital stay, and reduces the rates of postoperative spinal instability.

Spinal paraganglioma as unusual finding in von Hippel-Lindau disease

A 20-year-old patient with a history of von Hippel-Lindau disease reported on thoracic back pain radiating to the left shoulder for 10 weeks. Magnetic resonance imaging revealed a progressive contrast-enhancing tumor (14 × 21 × 28 mm) compressing the spinal cord and extending into the left neural foramen at T5/6. After embolization of supplying vessels, the tumor was completely resected via hemilaminectomy of T5. The postoperative course was uneventful without surgery related morbidity. The pathological examination disclosed a paraganglioma WHO grade I. We discuss the differential diagnoses and pitfalls of this unexpected finding in this patient with von Hippel-Lindau disease.