Decompression Alone Versus Interspinous/Interlaminar Device Placement for Degenerative Lumbar Pathologies: Systematic Review and Meta-Analysis.

INTRODUCTION: Interspinous devices (ISDs) and interlaminar devices (ILDs) are marketed as alternatives to conventional surgery for degenerative lumbar conditions; comparisons with decompression alone are limited. The present study reviews the extant literature comparing the cost and effectiveness of ISDs/ILDs with decompression alone. METHODS: Articles comparing decompression alone with ISD/ILD were identified; outcomes of interest included general and disease-specific patient-reported outcomes, perioperative complications, and total treatment costs. Outcomes were analyzed at <6 weeks, 3 months, 6 months, 1 year, 2 years, and last follow-up. Analyses were performed using random effects modeling. RESULTS: Twenty-nine studies were included in the final analysis. ILD/ISD showed greater leg pain improvement at 3 months (mean difference, -1.43; 95% confidence interval, [-1.78, -1.07]; P < 0.001), 6 months (-0.89; [-1.55, -0.24]; P = 0.008), and 12 months (-0.97; [-1.25, -0.68]; P < 0.001), but not 2 years (P = 0.22) or last follow-up (P = 0.09). Back pain improvement was better after ISD/ILD only at 1 year (-0.87; [-1.62, -0.13]; P = 0.02). Short-Form 36 physical component scores or Zurich Claudication Questionnaire (ZCQ) symptom severity scores did not differ between the groups. ZCQ physical function scores improved more after decompression alone at 6 months (0.35; [0.07, 0.63]; P = 0.01) and 12 months (0.23; [0.00, 0.46]; P = 0.05). Oswestry Disability Index and EuroQoL 5 dimensions scores favored ILD/ISD at all time points except 6 months (P = 0.07). Reoperations (odds ratio, 1.75; [1.23, 2.48]; P = 0.002) and total care costs (standardized mean difference, 1.19; [0.62, 1.77]; P < 0.001) were higher in the ILD/ISD group; complications did not differ significantly between the groups (P = 0.41). CONCLUSIONS: Patient-reported outcomes are similar after decompression alone and ILD/ISD; the observed differences do not reach accepted minimum clinically important difference thresholds. ISD/ILDs have higher associated costs and reoperation rates, suggesting current evidence does not support ILD/ISDs as a cost-effective alternative to decompression alone.

Treatment of intramedullary spinal cord tumors: a modified Delphi technique of the North American Spine Society Section of Spine Oncology.

OBJECTIVE: Intramedullary spinal cord tumors (IMSCTs) are rare tumors with heterogeneous presentations and natural histories that complicate their management. Standardized guidelines are lacking on when to surgically intervene and the appropriate aggressiveness of resection, especially given the risk of new neurological deficits following resection of infiltrative tumors. Here, the authors present the results of a modified Delphi method using input from surgeons experienced with IMSCT removal to construct a framework for the operative management of IMSCTs based on the clinical, radiographic, and tumor-specific characteristics. METHODS: A modified Delphi technique was conducted using a group of 14 neurosurgeons experienced in IMSCT resection. Three rounds of written correspondence, surveys, and videoconferencing were carried out. Participants were queried about clinical and radiographic criteria used to determine operative candidacy and guide decision-making. Members then completed a final survey indicating their choice of observation or surgery, choice of resection strategy, and decision to perform duraplasty, in response to a set of patient- and tumor-specific characteristics. Consensus was defined as ≥ 80% agreement, while responses with 70%-79% agreement were defined as agreement. RESULTS: Thirty-six total characteristics were assessed. There was consensus favoring surgical intervention for patients with new-onset myelopathy (86% agreement), chronic myelopathy (86%), or progression from mild to disabling numbness (86%), but disagreement for patients with mild numbness or chronic paraplegia. Age was not a determinant of operative candidacy except among frail patients, who were deemed more suitable for observation (93%). Well-circumscribed (93%) or posteriorly located tumors reaching the surface (86%) were consensus surgical lesions, and participants agreed that the presence of syringomyelia (71%) and peritumoral T2 signal change (79%) were favorable indications for surgery. There was consensus that complete loss of transcranial motor evoked potentials with a 50% decrease in the D-wave amplitude should halt further resection (93%). Preoperative symptoms seldom influenced choice of resection strategy, while a distinct cleavage plane (100%) or visible tumor-cord margins (100%) strongly favored gross-total resection. CONCLUSIONS: The authors present a modified Delphi technique highlighting areas of consensus and agreement regarding surgical management of IMSCTs. Although not intended as a substitute for individual clinical decision-making, the results can help guide care of these patients. Additionally, areas of controversy meriting further investigation are highlighted.

The Pterional Keyhole Craniotomy Approach: A Historical Perspective.

The pterional craniotomy is a workhorse of cranial surgery that provides access to the anterior and middle fossae. However, newer "keyhole" approaches, such as the micropterional or pterional keyhole craniotomy (PKC) can offer similar exposure for many pathologies while reducing surgical morbidity. The PKC is associated with shorter hospitalizations, reduced operative time, and superior cosmetic outcomes. Furthermore, it represents an ongoing trend toward smaller craniotomy size for elective cranial procedures. In this historical vignette, we trace the history of the PKC from its origins to its current role in the neurosurgeon's armamentarium.

Surgical Management of Hirayama Disease (Monomelic Amyotrophy): Systematic Review and Meta-Analysis of Patient-Level Data.

BACKGROUND: Hirayama disease or juvenile-onset monomelic amyotrophy is a clinical syndrome that disproportionately affects young males. Standard of care revolves around conservative management, but some patients experience disease progression that may benefit from surgical intervention. METHODS: Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic review of previous reports of surgical treatment for Hirayama disease was performed. Studies were included if they provided individual patient-level data, described the clinical presentation and surgical intervention, and reported neurological improvement at last follow-up. Comparison between those who improved and those with stable symptoms at last follow-up was performed. Decision-tree analysis was used to identify the best predictors of neurological improvement by last follow-up. RESULTS: Of 624 unique articles, 30 were included in the qualitative review and 23 in the meta-analysis. Among the 70 patients in the meta-analysis, mean age was 21.2 ± 6.3 years, 91% were male, and mean symptom duration at presentation was 43.3 ± 61.8 months. Fifty-nine patients (84.3%) had improvement in their neurological symptoms by last follow-up. Univariable analysis showed the only significant predictor of improvement in neurological symptoms by last follow-up was the use of stabilization-alone versus decompression with or without stabilization. Baseline clinical symptoms nor radiographic features predicted outcome. Decision-tree analysis showed surgical strategy (stabilization-alone vs. decompression ± stabilization), age (<20 vs. ≥20), and surgical approach (anterior-only vs. posterior-only or anterior-posterior) predicted a higher likelihood of neurological improvement by last follow-up. CONCLUSIONS: Nearly 85% of patients experienced improvement in neurological symptoms. Improvement was best for those who underwent stabilization-alone, and decision-tree analysis suggested that the likelihood of improvement was also superior for patients under 20 years of age and those treated with an anterior versus posterior or staged approach.

Operative Treatment of Bertolotti Syndrome: Resection Versus Fusion.

OBJECTIVE: To compare the outcomes of joint resection versus fusion in patients who undergo operative treatment for Bertolotti syndrome. METHODS: A chart review identified patients with Bertolotti syndrome who underwent operative treatment, consisting of either Bertolotti joint decompression/resection or fusion across the abnormal transitional lumbosacral vertebrae. Patients with other symptomatic operative spinal disease were excluded. RESULTS: Twenty-seven patients (9 men, 18 women) were identified for inclusion in the study with an average age of 40 ± 16 years, body mass index of 27 ± 5, and follow-up of 39 ± 48 months. Most patients presented with back pain (74%) or leg pain (48%) for an average duration of 61 ± 54 months. Nineteen (70%) presented with a Castellvi subtype 2a Bertolotti joint with computed tomography as the most common method for radiographic diagnosis (56%). When comparing long-term pain improvement (>12 months) after fusion (n = 9) versus joint resection (n = 18), more fusion patients reported improvement in their pain (78%) compared to joint resection (28%, P = 0.037). There was not a statistically significant difference in the short-term pain improvement (<6 months) between the fusion (100%) and resection (78%) patients (P = 0.27). There was no statistically significant difference between the two groups in terms of age, sex, body mass index, presenting symptoms, symptom duration, Bertolotti injection response, follow up, Castellvi subtype, and complications. CONCLUSIONS: Patients with Bertolotti syndrome who underwent surgical fusion across the transitional lumbosacral vertebrae had a higher rate of long-term pain improvement compared to patients who had resection of the abnormal pseudoarticulation.

Neuroblastoma of the Lumbar Spine.

Neuroblastoma is a primitive small-round-blue-cell tumor predominately found in pediatric patients. Few cases of neuroblastoma involving the adult spine have been reported. Herein we present the case of a healthy 34-year-old man treated for a large neuroblastoma involving the L3-5 vertebral bodies and prevertebral great vessels. Neoadjuvant chemotherapy led to significant cytoreduction, enabling en bloc resection of the initially unresectable tumor. Adjuvant differentiating therapy was employed, and curative radiation therapy was used to address the first instance of locoregional recurrence. The patient remains alive with stable disease more than 2 years after his initial diagnosis.

Translocation of Cervical Vertebral Body Replacement Device into the Esophagus.

Expandable vertebrectomy devices are a key technology that has facilitated the adoption of minimally invasive approaches to spine oncology surgery. However, advanced technology still requires proper attention to surgical fundamentals. Here we illustrate a cage of a misplaced expandable vertebrectomy device causing esophageal perforation. Examination of the postoperative radiographs suggests that haptic feedback from the expandable technology may have given the false impression of bony engagement. This case highlights the need for proper mortise work and complete visualization of the segments to be instrumented even during minimally invasive surgery.

Nerve Root Sparing En Bloc Resection of Sacral Chondrosarcoma: Technical Note and Review of the Literature.

BACKGROUND: Total en bloc sacrectomy provides the best long-term local control for large primary bony sacral tumors, but often requires lumbosacral nerve root sacrifice leading to loss of ambulation and/or bowel, bladder, and/or sexual dysfunction. Nerve-sparing techniques may be an option for some patients that avoid these outcomes and accordingly improve postoperative quality of life. OBJECTIVE: To describe the technique for a posterior-only en bloc hemisacrectomy with maximal nerve root preservation and to summarize the available literature. METHODS: A 38-yr-old woman with a 7.7 × 5.4 × 4.5 cm biopsy-proven grade 2 chondrosarcoma involving the left L5-S2 posterior elements underwent a posterior-only left hemisacrectomy tri-rod L3-pelvis fusion. A systematic review of the English literature was also conducted to identify other descriptions of high sacrectomy with distal sacral nerve root preservation. RESULTS: Computer-aided navigation facilitated an extracapsular resection that allowed preservation of the left-sided L5 and S3-Co roots. Negative margins were achieved and postoperatively the patient retained ambulation and good bowel/bladder function. Imaging at 9-mo follow-up showed no evidence of recurrence. The systematic review identified 4 prior publications describing 6 total patients who underwent nerve-sparing sacral resection. Enneking-appropriate resection was only obtained in 1 case though. CONCLUSION: Here we describe a technique for distal sacral nerve root preservation during en bloc hemisacrectomy for a primary sacral tumor. Few prior descriptions exist, and the present technique may help to reduce the neurological morbidity of sacral tumor surgery.

Interventions to minimize blood loss and transfusion risk in spine surgery: A narrative review.

Blood loss is an inevitable reality of spine surgery. Excessive loss is associated with increased morbidity and mortality and is frequently combated with allogeneic blood transfusions. Transfusions themselves are associated with increased morbidity, including circulatory overload, lung injury, and acute kidney injury. It is therefore incumbent upon the practicing spine surgeon to be aware of evidence-based interventions capable of reducing blood loss and the risk of transfusion. Here we review the available literature and make recommendation based upon the available evidence.

Radiographic and clinical outcomes of silicate-substituted calcium phosphate (SiCaP) bone grafts in spinal fusion: Systematic review and meta-analysis.

Pseudarthrosis continues to affect a nontrivial proportion of spine fusion patients. Given its ties to poorer patient outcomes and high reoperation rates, there remains great interest in interventions aimed at reducing the rates of nonunion. Recently, silicate-substituted calcium phosphate (SiCaP) bone grafts have been suggested to improve fusion rates, yet there exists no systematic review of the body of evidence for SiCaP grafts. Here, we present the first such review along with a meta-analysis of the effect of SiCaP bone grafts on fusion rates. Using the PubMed, Embase, and Web of Science databases, we queried the English-language literature for all studies examining the effect of SiCaPs on spinal fusion. Primary endpoints were: 1) radiographic fusion rate at last follow-up and 2) postoperative improvements in Visual Analog Scale (VAS) pain scores and Oswestry Disability Index (ODI) at last follow-up. Meta-analyses were performed for each endpoint using random effects. Ten articles (694 patients treated with SiCaP bone grafts) were included. Among SiCaP-treated patients, 93% achieved radiographic fusion (range: 79-100%), with comparable rates across subgroups. Meta-analysis of the three randomized controlled trials demonstrated no difference in fusion rates between SiCaP-treated patients and patients receiving grafts with recombinant human bone morphogenetic protein-2 (rhBMP-2) (OR: 1.11; p = 0.83). Patients treated with SiCaP bone grafts experienced significant improvements in VAS back pain (-3.3 points), VAS leg pain (-4.8 points), and ODI (-31.6 points) by last follow-up (p < 0.001 for each). Additional high-quality research is needed to evaluate the relative cost-effectiveness of SiCaP bone grafts in spinal fusion.

Improvement in vertebral endplate engagement following anterior column reconstruction using a novel expandable cage with self-adjusting, multiaxial end cap.

BACKGROUND: Destabilization of the vertebral column - as seen in trauma and metastatic spine disease - often requires corpectomy and anterior column reconstruction. Stresses applied to the implant can lead to subsidence, ultimately requiring in surgical revision. Here we report a cadaveric investigation of a novel expandable corpectomy cage with a self-adjusting, multiaxial end cap. METHODS: Four cadaveric T11-sacrum spines (mean 67.3 yr; 75% female) were treated with L2 corpectomy and T12-L4 pedicle screw fusion. Pressure sensors were applied to the L1 and L3 endplates and anterior column reconstruction was performed with either a standard expandable corpectomy cage (T2A), an expandable corpectomy cage with a self-adjusting, multiaxial end cap (T2S), or the latter cage with oblong, extended end caps (T2S + EE). Total contact area was compared pre- and post-reduction using ANOVA general linear model. RESULTS: Pre-reduction, the T2S constructs had a trend of higher surface contact than the conventional T2A constructs, though the results were not significant (p = 0.068); however, T2S + EE constructs did produce significantly larger contact with vertebral endplates (p = 0.04). The difference was also significant for both conditions following compression (p < 0.01 for both constructs). CONCLUSIONS: The use of an expandable corpectomy cage with a self-adjusting, multiaxial end cap produces significant increases in vertebral endplate contact area. These in vitro data suggest that the self-adjusting, multiaxial end cap may serve to decrease the risk of subsidence in patients undergoing anterior column resection and reconstruction. Clinical data would be required to confirm the relationship between endplate contact area and risk of subsidence.

Use of Intraoperative Indocyanine Green Angiography for Feeder Vessel Ligation and En Bloc Resection of Intramedullary Hemangioblastoma.

BACKGROUND: As vascular tumors, intramedullary hemangioblastomas are associated with significant intraoperative blood loss, making them particularly challenging clinical entities. The use of intraoperative indocyanine green or other fluorescent dyes has previously been described to avoid breaching the tumor capsule, but improved surgical outcomes may result from identifying and ligating the feeder arteries and arterialized draining veins. OBJECTIVE: To describe the use of combined preoperative angiography and intraoperative indocyanine green use for the identification of feeder arteries and arterialized draining veins to decrease blood loss in the resection of intramedullary hemangioblastomas. METHODS: A patient with cervical myelopathy secondary to a large C3 hemangioblastoma and cervicothoracic syrinx underwent a C2-3 laminoplasty with resection of the lesion. To reduce intraoperative blood loss and facilitate safe lesion resection, the vascular architecture of the lesion was defined via preoperative digital subtraction angiography and intraoperative use of indocyanine green. The latter permitted ligation of the major and minor feeding arteries and arterialized veins prior to tumor breach, allowing for facile en bloc resection of the lesion. RESULTS: The lesion was resected en bloc with minimal blood loss (approximately 100 mL) and without intraoperative neuromonitoring signal changes. The patient remained at neurological baseline throughout their stay. CONCLUSION: We present a written and media illustration of a technique for intraoperative indocyanine green use in the en bloc resection of intramedullary hemangioblastoma.

Immediate improvement of intraoperative monitoring signals following CSF release for cervical spine stenosis: Case report.

Cervical spondylotic myelopathy (CSM) is a degenerative pathology characterized by partial or complete conduction block on intraoperative neuromonitoring. We describe a case treated using osseoligamentous decompression and durotomy for cerebrospinal fluid (CSF) release. Intraoperative monitoring demonstrated immediate signal improvement with CSF release, suggesting that clinical improvement in CSM may result from resolution of CSF flow anomalies.