Daniel M. Sciubba

A novel classification system for spinal instability in neoplastic disease: an evidence-based approach and expert consensus from the Spine Oncology Study Group.

Study Design. Systematic review and modified Delphi technique. Objective. To use an evidence-based medicine process using the best available literature and expert opinion consensus to develop a comprehensive classification system to diagnose neoplastic spinal instability. Summary of Background Data. Spinal instability is poorly defined in the literature and presently there is a lack of guidelines available to aid in defining the degree of spinal instability in the setting of neoplastic spinal disease. The concept of spinal instability remains important in the clinical decision-making process for patients with spine tumors. Methods. We have integrated the evidence provided by systematic reviews through a modified Delphi technique to generate a consensus of best evidence and expert opinion to develop a classification system to define neoplastic spinal instability. Results. A comprehensive classification system based on patient symptoms and radiographic criteria of the spine was developed to aid in predicting spine stability of neoplastic lesions. The classification system includes global spinal location of the tumor, type and presence of pain, bone lesion quality, spinal alignment, extent of vertebral body collapse, and posterolateral spinal element involvement. Qualitative scores were assigned based on relative importance of particular factors gleaned from the literature and refined by expert consensus. Conclusion. The Spine Instability Neoplastic Score is a comprehensive classification system with content validity that can guide clinicians in identifying when patients with neoplastic disease of the spine may benefit from surgical consultation. It can also aid surgeons in assessing the key components of spinal instability due to neoplasia and may become a prognostic tool for surgical decision-making when put in context with other key elements such as neurologic symptoms, extent of disease, prognosis, patient health factors, oncologic subtype, and radiosensitivity of the tumor.

Spinal Instability Neoplastic Score: An Analysis of Reliability and Validity From the Spine Oncology Study Group

PURPOSE Standardized indications for treatment of tumor-related spinal instability are hampered by the lack of a valid and reliable classification system. The objective of this study was to determine the interobserver reliability, intraobserver reliability, and predictive validity of the Spinal Instability Neoplastic Score (SINS). METHODS Clinical and radiographic data from 30 patients with spinal tumors were classified as stable, potentially unstable, and unstable by members of the Spine Oncology Study Group. The median category for each patient case (consensus opinion) was used as the gold standard for predictive validity testing. On two occasions at least 6 weeks apart, each rater also scored each patient using SINS. Each total score was converted into a three-category data field, with 0 to 6 as stable, 7 to 12 as potentially unstable, and 13 to 18 as unstable. RESULTS The κ statistics for interobserver reliability were 0.790, 0.841, 0.244, 0.456, 0.462, and 0.492 for the fields of location, pain, bone quality, alignment, vertebral body collapse, and posterolateral involvement, respectively. The κ statistics for intraobserver reliability were 0.806, 0.859, 0.528, 0.614, 0.590, and 0.662 for the same respective fields. Intraclass correlation coefficients for inter- and intraobserver reliability of total SINS score were 0.846 (95% CI, 0.773 to 0.911) and 0.886 (95% CI, 0.868 to 0.902), respectively. The κ statistic for predictive validity was 0.712 (95% CI, 0.676 to 0.766). CONCLUSION SINS demonstrated near-perfect inter- and intraobserver reliability in determining three clinically relevant categories of stability. The sensitivity and specificity of SINS for potentially unstable or unstable lesions were 95.7% and 79.5%, respectively.

Diagnosis and management of metastatic spine disease: A review

With continued growth of the elderly population and improvements in cancer therapies, the number of patients with symptomatic spinal metastases is likely to increase, and this is a condition that commonly leads to debilitating neurological dysfunction and pain. Advancements in surgical techniques of resection and spinal reconstruction, improvements in clinical outcomes following various treatment modalities, generally increased overall survival in patients with metastatic spine disease, and a recent randomized trial by Patchell and colleagues demonstrating the superiority of a combined surgical/radiotherapeutic approach over a radiotherapy-only strategy have led many to suggest increasingly aggressive interventions for patients with such lesions. Optimal management of spinal metastases encompasses numerous medical specialties, including neurosurgery, orthopedic surgery, medical and radiation oncology, radiology, and rehabilitation medicine. In this review, the clinical presentation, diagnosis, and management of spinal metastatic disease are discussed. Ultimately, the goal of treatment in patients with spinal metastases remains palliative, and clinical judgment is required to select the appropriate patients for surgical intervention.

Recurrent disc herniation and long-term back pain after primary lumbar discectomy: review of outcomes reported for limited versus aggressive disc removal.

OBJECTIVEIt remains unknown whether aggressive disc removal with curettage or limited removal of disc fragment alone with little disc invasion provides a better outcome for the treatment of lumbar disc herniation with radiculopathy. We reviewed the literature to determine whether outcomes reported after limited discectomy (LD) differed from those reported after aggressive discectomy (AD) with regard to long-term back pain or recurrent disc herniation. METHODSA systematic MEDLINE search was performed to identify all studies published between 1980 and 2007 reporting outcomes after AD or LD for a herniated lumbar disc with radiculopathy. The incidence of short- and long-term recurrent back or leg pain and recurrent disc herniation was assessed from each reported LD or AD cohort and the cumulative incidence compared. RESULTSFifty-four studies (60 discectomy cohorts) met the inclusion criteria, reporting the outcomes of 13 359 patients after lumbar discectomy (LD, 6135 patients; AD, 7224 patients). The reported incidence of short-term recurrent back or leg pain was similar after LD (mean, 14.5%; range, 7–16%) and AD (mean, 14.1%; range, 6–43%) (P < 0.01). However, more than 2 years after surgery, the reported incidence of recurrent back or leg pain was 2.5-fold less after LD (mean, 11.6%; range, 7–16%) compared with AD (mean, 27.8%; range, 19–37%) (P < 0.0001). The reported incidence of recurrent disc herniation after LD (mean, 7%; range, 2–18%) was greater than that reported after AD (mean, 3.5%; range, 0–9.5%) (P < 0.0001). CONCLUSIONReview of the literature demonstrates a greater reported incidence of long-term recurrent back and leg pain after AD but a greater reported incidence of recurrent disc herniation after LD. Prospective, randomized trials are needed to firmly assess this possible difference.

Accuracy of Free-Hand Pedicle Screws in the Thoracic and Lumbar Spine: Analysis of 6816 Consecutive Screws

BACKGROUND:Pedicle screws are used to stabilize all 3 columns of the spine, but can be technically demanding to place. Although intraoperative fluoroscopy and stereotactic-guided techniques slightly increase placement accuracy, they are also associated with increased radiation exposure to patient and surgeon as well as increased operative time. OBJECTIVE:To describe and critically evaluate our 7-year institutional experience with placement of pedicle screws in the thoracic and lumbar spine using a free-hand technique. METHODS:We retrospectively reviewed records of all patients undergoing free-hand pedicle screw placement without fluoroscopy in the thoracic or lumbar spine between June 2002 and June 2009. Incidence and extent of cortical breach by misplaced pedicle screw was determined by review of postoperative computed tomography scans. We defined breach as more than 25% of the screw diameter residing outside of the pedicle or vertebral body cortex. RESULTS:A total of 964 patients received 6816 free-hand placed pedicle screws in the thoracic or lumbar spine. Indications for hardware placement were degenerative/deformity disease (51.2%), spondylolisthesis (23.7%), tumor (22.7%), trauma (11.3%), infection (7.6%), and congenital (0.9%). A total of 115 screws (1.7%) were identified as breaching the pedicle in 87 patients (9.0%). Breach occurred more frequently in the thoracic than the lumbar spine (2.5% and 0.9%, respectively; P < .0001) and was more often lateral (61.3%) than medial (32.8%) or superior (2.5%). T4 (4.1%) and T6 (4.0%) experienced the highest breach rate, whereas L5 and S1 had the lowest breach rate. Eight patients (0.8%) underwent revision surgery to correct malpositioned screws. CONCLUSION:Free-hand pedicle screw placement based on external anatomy alone can be performed with acceptable safety and accuracy and allows avoidance of radiation exposure encountered in fluoroscopic techniques. Image-guided assistance may be most valuable when placing screws between T4 and T6, where breach rates are highest.

Long-term clinical outcomes following en bloc resections for sacral chordomas and chondrosarcomas: a series of twenty consecutive patients.

Study Design. Retrospective study of 20 consecutive patients who underwent en bloc tumor excision of sacral chordomas and chondrosarcomas. Objective. To evaluate the functional and oncological outcomes following en bloc tumor excision for sacral chordomas and chondrosarcomas. Summary of Background Data. Chordomas and chondrosarcomas are 2 of the most common malignant primary tumors of the sacrum in adults. To date, few large clinical series with en bloc resection of these tumors exist. Methods. An institutional primary spine tumor surgical database was retrospective reviewed. Twenty consecutive patients with sacral chordomas and chondrosarcomas who underwent primary en bloc tumor excisions from 2002 to 2007 were included in the study. Surgical margin, perioperative complications, and postoperative functional status in these patients were analyzed. Disease-free survival following en bloc tumor excision was determined using the Kaplan-Meier method. Results. The study cohort included 8 males and 12 females with an average age of 53.5 years and a man follow-up of 47.8 months. Wide or marginal en bloc resection was achieved in 14 patients. In 6 other patients, tumor was identified at the surgical margins, and they were considered to have contaminated/intralesional resections. The 30-day perioperative morbidities in this series included 1 death from pulmonary embolism and 9 wound complications. Forty percent of the patients had normal bladder and bowel functions after surgery, while 60% of the patients had partial or complete loss of bladder and bowel functions. All but 2 patients in this group remained ambulatory after the surgery. The mean disease-free survival for patients with wide or marginal en bloc tumor excisions was 51 months, but the mean disease-free survival was only 17.5 months for patients who had contaminated/intralesional resections. Conclusion. Wide or marginal en bloc excision of sacral chordoma and chondrosarcoma is associated with significant improvement in disease-free survival with acceptable perioperative morbidity rate.

Factors associated with progression-free survival and long-term neurological outcome after resection of intramedullary spinal cord tumors: Analysis of 101 consecutive cases - Clinical article

OBJECT With the introduction of electrophysiological spinal cord monitoring, surgeons have been able to perform radical resection of intramedullary spinal cord tumors (IMSCTs). However, factors associated with tumor resectability, tumor recurrence, and long-term neurological outcome are poorly understood. METHODS The authors retrospectively reviewed 101 consecutive cases of IMSCT resection in adults and children at a single institution. Neurological function and MR images were evaluated preoperatively, at discharge, 1 month after surgery, and every 6 months thereafter. Factors associated with gross-total resection (GTR), progression-free survival (PFS), and long-term neurological improvement were assessed using multivariate regression analysis. RESULTS The mean age of the patients was 41 +/- 18 years and 17 (17%) of the patients were pediatric. Pathological type included ependymoma in 51 cases, hemangioblastoma in 15, pilocytic astrocytoma in 16, WHO Grade II astrocytoma in 10, and malignant astrocytoma in 9. A GTR was achieved in 60 cases (59%). Independent of histological tumor type, an intraoperatively identifiable tumor plane (OR 25.3, p < 0.0001) and decreasing tumor size (OR 1.2, p = 0.05) were associated with GTR. Thirty-four patients (34%) experienced acute neurological decline after surgery (associated with increasing age [OR 1.04, p = 0.02] and with intraoperative change in motor evoked potentials [OR 7.4, p = 0.003]); in 14 (41%) of these patients the change returned to preoperative baseline within 1 month. In 31 patients (31%) tumor progression developed by last follow-up (mean 19 months). Tumor histology (p < 0.0001) and the presence of an intraoperatively identified tumor plane (hazard ratio [HR] 0.44, p = 0.027) correlated with improved PFS. A GTR resulted in improved PFS for hemangioblastoma (HR 0.004, p = 0.04) and ependymoma (HR 0.2, p = 0.02), but not astrocytoma. Fifty-five patients (55%) maintained overall neurological improvement by last follow-up. The presence of an identifiable tumor plane (HR 3.1, p = 0.0004) and improvement in neurological symptoms before discharge (HR 2.3, p = 0.004) were associated with overall neurological improvement by last follow-up (mean 19 months). CONCLUSIONS Gross-total resection can be safely achieved in the vast majority of IMSCTs when an intraoperative plane is identified, independent of pathological type. The incidence of acute perioperative neurological decline increases with patient age but will improve to baseline in nearly half of patients within 1 month. Long-term improvement in motor, sensory, and bladder dysfunction may be achieved in a slight majority of patients and occurs more frequently in patients in whom a surgical plane can be identified. A GTR should be attempted for ependymoma and hemangioblastoma, but it may not affect PFS for astrocytoma. For all tumors, the intraoperative finding of a clear tumor plane of resection carries positive prognostic significance across all pathological types.

Predictors of ambulatory function after decompressive surgery for metastatic epidural spinal cord compression.

OBJECTIVEMetastatic epidural spinal cord compression (MESCC) is a relatively common and debilitating complication of metastatic disease that often results in neurological deficits. This study was designed to explore associations with maintaining and regaining ambulatory function after decompressive surgery for MESCC. METHODSSeventy-eight patients undergoing decompressive surgery for MESCC at an academic tertiary care institution between 1995 and 2005 were retrospectively reviewed. Fishers exact analysis was used to compare preoperative ambulatory and nonambulatory patients. Multivariate Cox proportional hazards regression was used to identify associations with either maintaining or regaining the ability to walk. RESULTSPatients were followed for 7.1 ± 1.6 (mean ± standard deviation) months after surgery. Preoperative nonambulatory patients required more extensive surgery (increased operative spinal levels and number of laminectomies) and had more surgical site complications (wound dehiscences and cerebrospinal fluid leaks) compared with preoperative ambulatory patients. From the multivariate analysis, preoperative ability to walk (relative risk [RR], 2.320; 95% confidence interval [CI], 1.301–4.416; P < 0.01) independently increased the likelihood of ambulation at the last follow-up evaluation 2.3-fold. Pathological vertebral compression fracture at presentation (RR, 0.471; 95% CI, 0.235–0.864; P = 0.01) independently decreased the likelihood of ambulation at the time of the last follow-up evaluation 2.1-fold. For patients unable to walk at the time of surgery, preoperative radiation therapy (RR, 0.406; 95% CI, 0.124–0.927; P = 0.03) decreased the likelihood of regaining the ability to walk 2.5-fold. Symptoms present for less than 48 hours (RR, 2.925; 95% CI, 1.133–2.925; P = 0.02) and postoperative radiotherapy (RR, 2.595; 95% CI, 1.039–8.796; P = 0.04) independently increased the likelihood of regaining ambulatory ability 2.9- and 2.6-fold, respectively, by the time of last follow-up evaluation. CONCLUSIONThe identification of these associations with neurological outcome may help guide in the preservation or return of ambulation after surgery for patients with MESCC.

Frameless stereotactic ventricular shunt placement for idiopathic intracranial hypertension.

Introduction: Cerebrospinal fluid (CSF) shunting effectively reverses symptoms of idiopathic intracranial hypertension (IIH). Lumboperitoneal (LP) shunts have traditionally been used in patients with IIH due to a frequently undersized ventricular system. However, the advent of image-guided stereotaxis has enabled effective ventricular catheter placement in patients with IIH. We describe the first large series of frameless stereotactic ventriculoperitoneal (VP) shunting for patients with slit ventricles and IIH. Methods: We describe the frameless stereotactic VP shunting technique for IIH in 32 procedures. Outcomes following shunt placement, time to shunt failure, and etiology of shunt failure are reported. Results: A total of 21 patients underwent 32 ventricular shunting procedures (20 VP, 10 ventriculoatrial, 2 ventriculopleural). One hundred percent of shunts were successfully placed into slit ventricles, all requiring only one pass of the catheter under stereotactic guidance to achieve the desired location and CSF flow. There were no procedure-related complications and each ventricular catheter showed rapid egress of CSF. All (100%) patients experienced significant improvement of headache immediately after shunting. Ten percent of ventricular shunts failed at 3 months after insertion, 20% failed by 6 months, 50% failed by 12 months, and 60% failed by 24 months. Shunt revision was due to distal obstruction in 67%, overdrainage in 20%, and distal catheter migration or CSF leak in 6.5%. There were no shunt revisions due to proximal catheter obstruction or shunt infection. Conclusions: In our experience treating patients with IIH, frameless stereotactic ventricular CSF shunts were extremely effective at treating IIH-associated intractable headache, and continued to provide relief in nearly half of patients 2 years after shunting without many of the shunt-related complications that are seen with LP shunts. Placing ventricular shunts using image-guided stereotaxis in patients with IIH despite the absence of ventriculomegaly is an effective, safe treatment option.

Detection of tumor-derived DNA in cerebrospinal fluid of patients with primary tumors of the brain and spinal cord

Significance Outcomes for individuals with central nervous system (CNS) malignancies remain abysmal. A major challenge in managing these patients is the lack of reliable biomarkers to monitor tumor dynamics. Consequently, many patients undergo invasive surgical procedures to determine disease status or experience treatment delays when radiographic testing fails to show disease progression. We show here that primary CNS malignancies shed detectable levels of tumor DNA into the surrounding cerebrospinal fluid (CSF), which could serve as a sensitive and exquisitely specific marker for quantifying tumor burden without invasive biopsies. Therefore, assessment of such tumor-derived DNA in the CSF has the potential to improve the management of patients with primary CNS tumors. Cell-free DNA shed by cancer cells has been shown to be a rich source of putative tumor-specific biomarkers. Because cell-free DNA from brain and spinal cord tumors cannot usually be detected in the blood, we studied whether the cerebrospinal fluid (CSF) that bathes the CNS is enriched for tumor DNA, here termed CSF-tDNA. We analyzed 35 primary CNS malignancies and found at least one mutation in each tumor using targeted or genome-wide sequencing. Using these patient-specific mutations as biomarkers, we identified detectable levels of CSF-tDNA in 74% [95% confidence interval (95% CI) = 57–88%] of cases. All medulloblastomas, ependymomas, and high-grade gliomas that abutted a CSF space were detectable (100% of 21 cases; 95% CI = 88–100%), whereas no CSF-tDNA was detected in patients whose tumors were not directly adjacent to a CSF reservoir (P < 0.0001, Fisher’s exact test). These results suggest that CSF-tDNA could be useful for the management of patients with primary tumors of the brain or spinal cord.