Direct (D)-Wave Monitoring Enhancement With Subdural Electrode Placement: A Case Series.

PURPOSE: Direct-wave (D-wave) neuromonitoring is a direct measure of corticospinal tract integrity that detects potential injury during spinal cord surgery. Epidural placement of electrodes used for D-wave measurements can result in high electrical impedances resulting in substantial signal noise that can compromise signal interpretation. Subdural electrode placement may offer a solution. METHODS: Medical records for consecutive patients with epidural and subdural D-wave monitoring were reviewed. Demographic and clinical information including preoperative and postoperative motor strength were recorded. Neuromonitoring charts were reviewed to characterize impedances and signal amplitudes of D-waves recorded epidurally (before durotomy) and subdurally (following durotomy). Nonparametric statistics were used to compare epidural and subdural D-waves. RESULTS: Ten patients (50% women, median age 50.5 years) were analyzed, of which five patients (50%) were functionally independent (modified McCormick grade ≤ II) preoperatively. D-waves were successfully acquired by subdural electrodes in eight cases and by epidural electrodes in three cases. Subdural electrode placement was associated with lower impedance values ( P = 0.011) and a higher baseline D-wave amplitude ( P = 0.007) relative to epidural placement. No association was observed between D-wave obtainability and functional status, and no adverse events relating to subdural electrode placement were encountered. CONCLUSIONS: Subdural electrode placement allows successful D-wave acquisition with accurate monitoring, clearer waveforms, and a more optimal signal-to-noise ratio relative to epidural placement. For spinal surgeries where access to the subdural compartment is technically safe and feasible, surgeons should consider subdural placement when monitoring D-waves to optimize clinical interpretation.

The diagnostic accuracy of neuromonitoring for detecting postoperative bowel and bladder dysfunction in spinal oncology surgery: a case series.

PURPOSE: Postoperative bowel and bladder dysfunction (BBD) poses a significant risk following surgery of the sacral spinal segments and sacral nerve roots, particularly in neuro-oncology cases. The need for more reliable neuromonitoring techniques to enhance the safety of spine surgery is evident. METHODS: We conducted a case series comprising 60 procedures involving 56 patients, spanning from September 2022 to January 2024. We assessed the diagnostic accuracy of sacral reflexes (bulbocavernosus and external urethral sphincter reflexes) and compared them with transcranial motor evoked potentials (TCMEP) incorporating anal sphincter (AS) and external urethral sphincter (EUS) recordings, as well as spontaneous electromyography (s-EMG) with AS and EUS recordings. RESULTS: Sacral reflexes demonstrated a specificity of 100% in predicting postoperative BBD, with a sensitivity of 73.33%. While sensitivity slightly decreased to 64.71% at the 1-month follow-up, it remained consistently high overall. TCMEP with AS/EUS recordings did not identify any instances of postoperative BBD, whereas s-EMG with AS/EUS recordings showed a sensitivity of 14.29% and a specificity of 97.14%. CONCLUSION: Sacral reflex monitoring emerges as a robust adjunct to routine neuromonitoring, offering surgeons valuable predictive insights to potentially mitigate the occurrence of postoperative BBD.

Digital Preoperative Huddle Platform Use Leads to Decreased Surgical Cost.

BACKGROUND AND OBJECTIVES: Communication has a well-established effect on improving outcomes. The current study evaluated the effect of multidisciplinary preoperative team communication using a digital huddle software platform on operating room costs. METHODS: A digital huddle software platform was implemented in March 2022 for neurosurgical procedures performed at a single tertiary care center. Surgeons were encouraged, but not required, to participate. General linear models were used to test the association between participation and the difference in supply-related cost and case length, using intergroup comparison and historical controls. RESULTS: A total of 29626 cases (performed by 97 surgeons), conducted between March 2021 and June 2023, were included in our analysis. Cases from participating neurosurgeons (12 surgeons, 4064 cases) were compared with cases from nonparticipating neurosurgeons (6 surgeons, 2452 cases), non-neurosurgery cases carried out by the same operating room staff (20 orthopedic spine surgeons, 6073 cases), and non-neurosurgery cases performed in a different operating room unit (59 surgeons, 21 996 cases). In aggregate, operating room (OR) costs increased by 7.3% (95% CI: 0.9-14.1, P = .025) in the postintervention period. In the same period, participation in the digital huddle platform was associated with an OR utilization and supply-related cost decrease of 16.3% (95% CI: 8.3%-23.6%, P < .001). Among neurosurgeons specifically, participation was associated with a supply-related cost decrease of 17.5% (95% CI: 6.0%-27.5%, P = .0037). There was no change in case length (median case length 171 minutes, change: +2.7% increase, 95% CI:-2.2%-7.9%, P = .28). CONCLUSION: The implementation of a digital huddle software platform resulted in an OR utilization and supply cost decrease among participants during a period when the overall nonparticipating control cohort experienced an increase in cost.

Carbon fiber-reinforced PEEK spinal implants for primary and metastatic spine tumors: a systematic review on implant complications and radiotherapy benefits.

OBJECTIVE: By minimizing imaging artifact and particle scatter, carbon fiber-reinforced polyetheretherketone (CF-PEEK) spinal implants are hypothesized to enhance radiotherapy (RT) planning/dosing and improve oncological outcomes. However, robust clinical studies comparing tumor surgery outcomes between CF-PEEK and traditional metallic implants are lacking. In this paper, the authors performed a systematic review of the literature with the aim to describe clinical outcomes in patients with spine tumors who received CF-PEEK implants, focusing on implant-related complications and oncological outcomes. METHODS: A systematic review of the literature published between database inception and May 2022 was performed in accordance with the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The PubMed database was queried using the terms "carbon fiber" and "spine" or "spinal." The inclusion criteria were articles that described patients with CF-PEEK pedicle screw fixation and had a minimum of 5 patients. Case reports and phantom studies were excluded. RESULTS: This review included 11 articles with 326 patients (237 with CF-PEEK-based implants and 89 with titanium-based implants). The mean follow-up period was 13.5 months, and most tumors were metastatic (67.1%). The rates of implant-related complications in the CF-PEEK and titanium groups were 7.8% and 4.7%, respectively. The rate of pedicle screw fracture was 1.7% in the CF-PEEK group and 2.4% in the titanium group. The rates of reoperation were 5.7% (with 60.0% because of implant failure or junctional kyphosis) and 4.8% (all because of implant failure or junctional kyphosis) in the CF-PEEK and titanium groups, respectively. When reported, 72.5% of patients received postoperative RT (41.0% stereotactic body RT, 30.8% fractionated RT, 25.6% proton, 2.6% carbon ion). Four articles suggested that implant artifact was reduced in the CF-PEEK group. Local recurrence occurred in 14.4% of CF-PEEK and 10.7% of titanium-implanted patients. CONCLUSIONS: While CF-PEEK harbors similar implant failure rates to traditional metallic implants with reduced imaging artifact, it remains unclear whether CF-PEEK implants improve oncological outcomes. This study highlights the need for prospective, direct comparative clinical studies.

Extreme Lateral Approach to the Craniocervical Junction, Operative Technique and Approach Essentials: 2-Dimensional Operative Video.

INDICATIONS CORRIDOR AND LIMITS OF EXPOSURE: The extreme lateral approach is useful for both extradural and intradural anterior and anterolateral lesions at the lower clivus down to the level of C2. ANATOMIC ESSENTIALS NEED FOR PREOPERATIVE PLANNING AND ASSESSMENT: The patient is evaluated with MRI, computed tomography (CT), and an angiogram. Special attention is given to vascular (vertebral artery course, dominance, tumor feeders) and bony (occipital condyle, jugular tubercle, foramen magnum and extent of bony involvement) anatomy. ESSENTIALS STEPS OF THE PROCEDURE: The patient is positioned lateral with the head flexed and tilted down without axial rotation. A hockey-stick incision is performed, and the myocutaneous flap is raised. A retrocondylar craniectomy is performed. The extradural vertebral artery is exposed for proximal control. A C1 hemilaminectomy is performed. Cephalad/caudal exposure and drilling of the occipital condyle are determined per case. The dura is opened, and the vertebral artery is released at the dural entry point to facilitate the tumor removal. The tumor is debulked and delivered inferoventrally away from the neuroaxis and cranial nerves. After removing the tumor, the dura is closed using an allograft.The patients consented to the procedure and to the publication of their images. PITFALLS/AVOIDANCE OF COMPLICATIONS: • Cranial nerve deficits• Craniocervical instability• Postoperative hydrocephalus• Postoperative pseudomeningocele. VARIANTS AND INDICATIONS FOR THEIR USE: A transmastoid extension of the craniectomy allows access further rostrally in the clivus. For C1-2 chordomas, the approach is extended inferiorly, and the vertebral artery is mobilized out of the C1-2 transverse foramina. For tumors involving the joints, an occipitocervical stabilization is required.Images in video reused with permission as follows: image at 00:16 from Revuelta Barbero et al, Endoscopic endonasal transclival-medial condylectomy approach for resection of a foramen magnum meningioma: 2-dimensional operative video, Oper Neurosurg , 16(2), 2018, by permission from the Congress of Neurological Surgery; images at 00:30, and top image at 00:52 reused from Wen et al, Microsurgical anatomy of the transcondylar, supracondylar, and paracondylar extensions of the far-lateral approach, J Neurosurg , 87(4), 1997, with permission from JNSPG; bottom images at 00:52 from Muthukumar et al, A morphometric analysis of the foramen magnum region as it relates to the transcondylar approach, Acta Neurochir , 147(8), 2005, by permission from Springer Nature.

Digital Biomarkers and the Evolution of Spine Care Outcomes Measures: Smartphones and Wearables.

Over the past generation, outcome measures in spine care have evolved from a reliance on clinician-reported assessment toward recognizing the importance of the patient's perspective and the wide incorporation of patient-reported outcomes (PROs). While patient-reported outcomes are now considered an integral component of outcomes assessments, they cannot wholly capture the state of a patient's functionality. There is a clear need for quantitative and objective patient-centered outcome measures. The pervasiveness of smartphones and wearable devices in modern society, which passively collect data related to health, has ushered in a new era of spine care outcome measurement. The patterns emerging from these data, so-called "digital biomarkers," can accurately describe characteristics of a patient's health, disease, or recovery state. Broadly, the spine care community has thus far concentrated on digital biomarkers related to mobility, although the researcher's toolkit is anticipated to expand in concert with advancements in technology. In this review of the nascent literature, we describe the evolution of spine care outcome measurements, outline how digital biomarkers can supplement current clinician-driven and patient-driven measures, appraise the present and future of the field in the modern era, as well as discuss present limitations and areas for further study, with a focus on smartphones (see Supplemental Digital Content , http://links.lww.com/NEU/D809 , for a similar appraisal of wearable devices).

Perioperative team communication through a mobile app for improving coordination and education in neurosurgery cases.

OBJECTIVE: Miscommunication and poor coordination among surgical teams are known causes of preventable medical harms and operating room inefficiencies and inhibit surgical training. Technology may help overcome these challenges. This study used the personal experience of one of the authors as a former Air Force F-15 pilot to design a combat aviation pre- and postoperative communication workflow in the neurosurgery department and tested its effect on safety, efficiency, and education. The authors hypothesized that the adoption of this workflow through a tailored technological platform will increase compliance and improve the chances of sustainability. METHODS: Data were prospectively collected from neurosurgery cases before (January-May 2020) and after (June-October 2020) implementation of this workflow. Briefing and debriefing were executed using a custom mobile platform and were defined as nonmandatory for all participants. All faculty and residents who operated at NYU Langone Medical Center (Tisch campus) during the intervention period were enrolled on the platform. Primary outcomes were morbidity and mortality per the department's criteria, and intraoperative last-minute requests as reported by operating room staff in a double-blinded fashion. Secondary outcomes were user responses on the subjective questionnaires. RESULTS: Data were collected from 637 and 893 cases during the preintervention and intervention periods, respectively. The average briefing rates for residents and surgeons were 71% and 81%, respectively, and the average debriefing rates for residents and surgeons were 67% and 88%. There was no significant difference in preoperative risk score between the preintervention and intervention patient populations (p = 0.24). The rate of intraoperative last-minute requests significantly decreased from 16.6% (35/211) to 10.5% (35/334, p = 0.048). There was no significant change in morbidity and mortality between the preintervention and intervention periods. On subjective questionnaires there was a statistically significant improvement in safety, efficiency, and educational aspects of the cases during the intervention period. CONCLUSIONS: Implementation of aviation-like structured team communication practices in the neurosurgery department through a technological platform improved education and communication between surgical teams and led to a reduction in last-minute surgical requests that could impact costs.

Fusing to the Sacrum/Pelvis: Does the Risk of Reoperation in Thoracolumbar Fusions Depend on Upper Instrumented Vertebrae (UIV) Selection?

BACKGROUND: There is controversy as to whether fusions should have the upper instrumented vertebrae (UIV) end in the upper lumbar spine or cross the thoracolumbar junction. This study compares outcomes and reoperation rates for thoracolumbar fusions to the sacrum or pelvis with UIV in the lower thoracic versus lumbar spine to determine if there is an increased reoperation rate depending on UIV selection. METHODS: A retrospective review of prospectively collected data was conducted from a single-center database on adult patients with degeneration and deformity who underwent primary and revision fusions with a caudal level of S1 or ilium between 2012 and 2018. Fusions were classified as anterior, posterior, or combination approach. Revision fusions included patients who had spinal surgery at another institution prior to their revision surgery at the center. Patients were categorized into 1 of 3 groups based on UIV: T9-T11, upper lumbar region (L1-L2), and lower lumbar region (L3-L5). Inclusion criteria were age 18 years or older and at least 1 year of clinical follow-up. Patients were excluded from analysis if they had tumors, infections, or less than 1 year of follow-up after the index procedure. RESULTS: The reoperation rates for the UIV groups in the thoracic (28%) and upper lumbar (27%) spine were nearly equal in magnitude and were both significantly higher than the reoperation rate in the lower lumbar group (18%, P = .046). Reoperation for the diagnosis of adjacent segment disease was 8.3% in the upper lumbar spine and statistically significantly higher than the reoperation rates for adjacent segment disease in the thoracic (1%) or lower lumbar (4.5%, P = .042) spine. Reoperations for pseudoarthrosis and proximal junctional kyphosis were 13% and 4%, respectively, in the thoracic spine, both of which were statistically significantly different (pseudoarthrosis, P = .035; proximal junctional kyphosis, P = .002) from the reoperation rates for the same diagnoses in the upper lumbar spine (4.6% and 1%) or lower lumbar spine (6.2% and 0%). A multivariate logistical regression model at 2-year follow up did not show a statistically significant difference between reoperation rates between the thoracic and upper lumbar spine UIV groups. CONCLUSION: Constructs with UIV in the thoracic spine suffer from higher rates of proximal junctional kyphosis and pseudoarthrosis, whereas those with UIV in the upper lumbar spine have higher rates of adjacent segment disease. Given this tradeoff, there is no certain recommendation on what UIV will result in a lower reoperation rate in thoracolumbar fusion constructs to the sacrum or pelvis. Surgeons must evaluate patient characteristics and risks to make the optimal decision.

Intradural primary marginal zone lymphoma of the cervical spine 2 years following a posterior cervical instrumented fusion.

Primary low grade central nervous system lymphoma is a rare entity, with the majority being intracranial marginal zone B-cell lymphoma. Primary spinal lymphoma is unusual, and commonly presents as an epidural lesion with diffuse large B-cell histology, as described in prior literature. We present a case of a 56 year-old woman diagnosed with a primary intradural spinal lymphoma two years after a posterior cervical fusion at the same level. She was treated successfully with surgical resection and postoperative radiotherapy. To our knowledge, this is the first case in the literature describing an intradural primary marginal zone B-cell lymphoma of the spine.

Neurofibromatosis Type 1-Related Hydrocephalus: Treatment Options and Considerations.

OBJECTIVE: Neurofibromatosis type I (NF1) will be associated with hydrocephalus in ≤13% of cases. Currently, very little data are available describing the actual etiologies and treatment options of NF1-associated hydrocephalus. We, therefore, have described our experience in treating NF1-associated hydrocephalus. METHODS: We completed a retrospective data analysis of 1020 patients with NF1 treated at the Gilbert's Israeli International Neurofibromatosis Center during a period of 20 years. The patients presenting with, and treated for, related hydrocephalus were included. The clinical, radiological, and surgical data are presented. RESULTS: We included 22 patients (2.1% of the entire NF1 patient cohort), with 17 aged <19 years. Twenty patients had obstructive hydrocephalus. The most common etiologies included aqueductal or third ventricular obstruction. Of the 22 patients, 15 had underwent endoscopic procedures (14 third ventriculostomies) and 7 had undergone shunt procedures. The corresponding failure rates (including the need for additional cerebrospinal fluid procedures) were 60% and 71%. CONCLUSIONS: Hydrocephalus in the context of NF1 has been caused mostly by obstructive etiologies. A tailored treatment approach is recommended to address the specific etiology. Regardless of the treatment approach, a relatively high rate of failure has been described.

The interhemispheric approach in children: our experience and review of the literature.

OBJECTIVE: The interhemispheric approach (IA) has been extensively described for treating pathologies located at the lateral or third ventricle, pineal region, and periventricular locations. While these anatomical locations are the target of many pediatric pathologies, very few series have analyzed the morbidity and outcome of the IA in children. The aim of this study is to describe our experience using the IA in children, emphasizing the approach-related morbidity. METHODS: Twenty-six patients underwent 28 procedures using the IA between the years 2012 and 2016. Data for these patients was retrospectively analyzed. Surgical and approach-related morbidity were collected and analyzed. RESULTS: The mean age of the cohort was 10.1 ± 4.2 years and included 15 females (57.7%). Approach-related morbidity occurred following eight surgeries (28.6%; seven with anterior IA and one with posterior IA), including two pseudomeningoceles (7.1%), three persistent subdural effusions (10.7%), of which two were locally drained and one required subduro-peritoneal shunting, one epidural bleed (3.6%) which resolved spontaneously, and two infections (3.6%) treated with antibiotics. Cerebrospinal fluid leaks, supplementary motor area syndrome, seizures, and subdural hematomas did not occur in any of the patients. None of the approach-related complications led to permanent morbidity or to mortality. CONCLUSION: The IA for lesions in and around the ventricular system is feasible and associated with a low permanent complication rate. When choosing this approach, the morbidity, although rarely permanent, should be considered.

Endoscopic Third Ventriculostomy in Patients with Neurofibromatosis Type 1: A Multicenter International Experience.

BACKGROUND: Hydrocephalus in patients with neurofibromatosis (NF) type 1 is usually obstructive and may arise secondary to tumoral or nontumoral causes. Treatment of hydrocephalus in these patients is often challenging owing to combined pathologies and unique anatomic changes. The use of endoscopic third ventriculostomy (ETV) as treatment has rarely been described in this group. We aimed to characterize indications, considerations, and outcome of ETV in patients with NF 1 gathered in a multicenter international cohort. METHODS: Five centers participated in this retrospective study. Following institutional review board approval, data and images were collected. Patients of all ages with NF 1 who underwent ETV for treatment of obstructive hydrocephalus were included. Patients who had no postoperative radiologic or clinical follow-up were excluded. ETV failure was defined as recurrent clinical or radiologic signs of hydrocephalus. RESULTS: The study included 42 patients. Common etiologies for hydrocephalus were aqueductal/tectal tumor (31%), aqueductal web (26%), and aqueductal stenosis owing to NF-related changes (14%). Ten patients had a preoperative diagnosis of optic pathway glioma. ETV failures were identified in 6 patients within 1 month, in 3 patients within 9 months, and in 1 patient within 4 years. ETV was successful in 32 patients (76%) with a mean follow up of 59.4 months ± 50.9 (range, 4 months to 15 years). CONCLUSIONS: ETV is a safe treatment for selected patients with NF 1 and obstructive hydrocephalus. Individual anatomic and pathologic aspects should be taken into consideration.