Minimally Invasive Technique for Chiari I Decompression Without Durotomy: Surgical Technique and Preliminary Case Series.

BACKGROUND: Chiari I malformation, marked by severe headaches and potential brainstem/spinal cord issues, often requires surgical intervention when conservative methods fail. This study introduces a minimally invasive surgery (MIS) Chiari decompression technique utilizing a 3-blade retractor, aiming to reduce postoperative discomfort and optimize outcomes. METHODS: Chiari type I malformation patients who underwent a MIS technique were included. Technique consisted of a minimal-soft tissue opening using a 3-blade retractor, suboccipital craniectomy, C1 laminectomy, and resection of the atlantooccipital band without a durotomy. RESULTS: Ten patients were treated. Mean age was 43.3 years, with 7 female patients. All patients presented with occipital headaches; 50% retroorbital pain; 40% neck, upper back, or shoulder pain; and 30% limb paresthesias. Median pre-surgical modified Rankin Scale (mRS) was 3 (2-4) and pain visual analog score (VAS) was 7 (5-9). Mean operative time was 59 (59-71) minutes, with mean blood loss of 88.5 (50-140) mL. In our sample, 90% of patients were discharged the same surgical day (mean 7.2 [5.3-7.7] hours postoperative). No immediate or delayed postoperative complications were evidenced. At 6 months, 90% of patients had mRS 0-1. At last follow-up the mean VAS was 1.5 (range: 0-4, P < 0.001). CONCLUSIONS: The MIS 3-blade flexible retractor technique for Chiari decompression is feasible, provides wide visualization angles of the suboccipital region and C1 arch, allows 2-surgeon work, and minimizes skin and soft tissue disruption. This combination may diminish postoperative discomfort, reduce the risk of surgical site infections, and optimize outcomes.

Managing Disease-Modifying Antirheumatic Drugs (DMARDs) for Patients Undergoing Elective Spine Surgery: A Pilot Survey.

Introduction: Patients affected by autoimmune pathologies such as rheumatoid arthritis require surgery for various reasons. However, the systemic inflammatory nature of these disease processes often necessitates therapy with disease-modifying antirheumatic drugs (DMARDs). Alteration of these agents in the perioperative period for surgery requires a careful risk-benefit analysis to limit disease flares, infection rates, and secondary revisions. We therefore queried North and South American practices for perioperative management of DMARDs in patients undergoing elective spine surgery. Methods: An institutional review board-approved pilot survey was disseminated to spine surgeons regarding how they managed DMARDs before, during, and after spine surgery. Results: A total of 47 spine surgeons responded to the survey, 37 of whom were neurosurgeons (78.7%) and 10 orthopedic surgeons (21.3%). Of the respondents, 80.9% were from North America, 72.3% were board-certified, 51.1% practiced in academic institutions, and 66.0% performed 50-150 spine surgeries per year. Most respondents consulted a rheumatologist before continuing or withholding a DMARD in the perioperative period (70.2%). As such, a majority of the spine surgeons in this survey withheld DMARDs at an average of 13.8 days before and 19.6 days after spine surgery. Of the spine surgeons who withheld DMARDs before and after spine surgery, the responses were variable with a trend toward no increased risk of postoperative complications. Conclusions: Based on the results of this pilot survey, we found a consensus among spine surgeons to withhold DMARDs before and after elective spine surgery.

Nonoperative versus operative management of type II odontoid fracture in older adults: a systematic review and meta-analysis.

OBJECTIVE: Odontoid fractures are the most common fracture of the cervical spine in adults older than 65 years of age. Fracture management remains controversial, given the inherently increased surgical risks in older patients. The objective of this study was to compare fusion rates and outcomes between operative and nonoperative treatments of type II odontoid fractures in the older population. METHODS: A systematic literature review was performed to identify studies reporting the management of type II odontoid fractures in patients older than 65 years from database inception to September 2022. A meta-analysis was performed to compare rates of fusion, stable and unstable nonunion, mortality, and complication. RESULTS: Forty-six articles were included in the final review. There were 2822 patients included in the different studies (48.9% female, 51.1% male), with a mean ± SD age of 81.5 ± 3.6 years. Patients in the operative group were significantly younger than patients in the nonoperative group (81.5 ± 3.5 vs 83.4 ± 2.5 years, p < 0.001). The overall (operative and nonoperative patients) fusion rate was 52.9% (720/1361). The fusion rate was higher in patients who underwent surgery (74.3%) than in those who underwent nonoperative management (40.3%) (OR 4.27, 95% CI 3.36-5.44). The likelihood of stable or unstable nonunion was lower in patients who underwent surgery (OR 0.37, 95% CI 0.28-0.49 vs OR 0.32, 95% CI 0.22-0.47). Overall, 4.8% (46/964) of nonoperatively managed patients subsequently required surgery due to treatment failure. Patient mortality across all studies was 16.6% (452/2721), lower in the operative cohort (13.2%) than the nonoperative cohort (19.0%) (OR 0.64, 95% CI 0.52-0.80). Complications were more likely in patients who underwent surgery (26.0% vs 18.5%) (OR 1.55, 95% CI 1.23-1.95). Length of stay was also higher with surgery (13.6 ± 3.8 vs 8.1 ± 1.9 days, p < 0.001). CONCLUSIONS: Patients older than 65 years of age with type II odontoid fractures had higher fusion rates when treated with surgery and higher stable nonunion rates when managed nonoperatively. Complications and length of stay were higher in the surgical cohort. Mortality rates were lower in patients managed with surgery, but this phenomenon could be related to surgical selection bias. Fewer than 5% of patients who underwent nonoperative treatment required revision surgery due to treatment failure, suggesting that stable nonunion is an acceptable treatment goal.

Utility of Magnetic Resonance Imaging for Ligamentous Injury in Cervical Spine Trauma: A 2-Year Consecutive Case Cohort.

BACKGROUND: Magnetic resonance imaging (MRI) is increasingly used as an adjunct to spinal soft tissue evaluation in cervical spine (C-spine) trauma; however, the utility of this information remains controversial. In this consecutive observational study, we reviewed the utility of MRI in patients with C-spine trauma. METHODS: We identified patients in real time over a 2-year period as they presented to our level 1 trauma center for C-spine computed tomography (CT) scan followed by MRI. MRI was obtained by the trauma team prior to the spine service consultation if (1) they were unable to clear the C-spine according to protocol or (2) if the on-call radiologist reported a concern for ligamentous integrity from the CT findings. RESULTS: Thirty-three patients, including 19 males (58%) and 14 females, with a mean age of 54 years, were referred to the spine service for concerns of ligamentous instability. The most common mechanisms of injury were motor vehicle accidents (n = 13) and falls (n = 11). MRI demonstrated ligamentous signal change identified by the radiologist as potentially unstable in all patients. Fifteen patients (45%) had multiple C-spine ligaments affected. The interspinous ligament was involved most frequently (28%), followed by the ligamentum flavum (21%) and supraspinous ligament (15%). All patients underwent dynamic upright C-spine X-rays that were interpreted by both the ordering surgeon and radiologist. There was no evidence of instability in any patient; concurrence between X-ray interpretation was 100%. The cervical collar was successfully removed in all cases. No patients required late surgical intervention, and there were no return visits to the emergency department of a spinal nature. CONCLUSIONS: MRI signal change within the ligaments of the C-spine should be interpreted with caution in the setting of trauma. To physicians less familiar with spinal biomechanics, MRI findings may be perceived in an inadvertently alarming manner. Bony alignment and, when indicated, dynamic upright X-rays remain the gold standard for evaluating the ligamentous integrity of the C-spine.

Evaluation of the Thoracolumbar Injury Classification and Severity (TLICS) Score Over a Two-Year Period at a Level One Trauma Center.

Introduction The use of the Thoracolumbar Injury Classification and Severity Score (TLICS) and other classification systems for guiding the management of traumatic spinal injuries remains controversial. TLICS is one of the few classifications that provides treatment recommendations.We sought to analyze intervention modality selection based on the TLICS scoring system. Methods A retrospective review of patients presenting with traumatic thoracolumbar fractures at a level 1 trauma center over a two-year period was performed. Primary endpoints for comparison analysis included visual analog scale (VAS) scores and Cobb angles during follow-up. Results There were 272 patients with thoracolumbar fractures, of whom 212 had TLICS of ≤3, six with TLICS of 4, and 54 with TLICS of ≥5. Of the 272 total patients, 59 were treated via surgery and 213 via non-surgical conservative methods. The VAS scores significantly decreased from presentation to last follow-up in both surgically treated and conservative groups (p<0.0001). This remained consistent in subgroup analyses of TLICS ≤ 3, TLICS = 4, and TLICS ≥ 5 (p<0.0001). Burst fractures treated conservatively had larger fracture Cobb angles versus those treated via surgery at the last follow-up, although this was not significantly associated (p=0.07). The only significant relationship with Cobb angles was in distraction fractures of the TLICS > 4 conservative group, who had significantly lower Cobb angles at the last follow-up than the TLICS > 4 surgical group (p<0.04). The "surgeon's choice" for TLICS = 4 was surgical intervention (4/6 patients, 66.7%). Conclusion Using the TLICS score, thoracolumbar injuries in a level 1 trauma center are more commonly TLICS ≤ 3. For patients with TLICS = 4, the surgeon's choice was most commonly surgical repair. VAS scores decreased over time from presentation between surgically and conservatively managed patients (as well as within-group analyses). The data concerning Cobb angles were more ambiguous, as larger Cobb angles in burst fractures treated conservatively did not show statistically significant differences with surgery.

Predictors of revision surgery after bedside subdural drain placement for chronic subdural hematomas.

BACKGROUND AND OBJECTIVE: For chronic subdural hematoma (cSDH), bedside subdural drains (SDD) provide a useful alternative to more invasive neurosurgical techniques, including evacuation through multiple burr holes or formal craniotomy. However, no scale currently exists adequately predicting SDD candidacy or treatment response. The present study sought to characterize predictors of revision surgery after initial treatment with bedside SDD for cSDH. METHODS: We conducted a retrospective case control study of cSDH patients treated with bedside SDD at a level one trauma center between 2018 and 2022. Binomial regression was used to compare SDD patients and generate odds ratios associated with revision surgery, which were compared using a binary random effects model. RESULTS: Ninety six cSDH patients were included, of whom 13 (13.5%) required a revision surgery after initial treatment failure with bedside SDD. Patients requiring revision surgery demonstrated an increased male predominance (84.6% vs. 69.9% of SDD patients not requiring revision surgery), tended to be younger (67.8 vs. 70.5 years) with a greater body mass index (28.7 vs. 25.6 kg/m2), and have a lower Glasgow Coma Scale (GCS) score on presentation of 12.5 (versus 14). Patients with an initial GCS score less than 13 (OR 11.0 95% CI 2.8 - 43.3), midline shift greater than 10 mm on CT (OR 6.5 95% CI 1.7 - 25.7), or duration of SDD placement longer than 3 days (OR 10.5 95% CI 2.6 - 41.9) demonstrated a greater likelihood of needing a revision surgery after initial treatment with bedside SDD. CONCLUSION: Among patients treated with SDD, we identified 3 independent factors predicting the need for revision surgery: GCS score, midline shift, and duration of drain placement. Craniotomy may be favored over bedside SDD in patients presenting with a GCS score less than 13 or midline shift greater than 10 mm and for SDD patients demonstrating inadequate clinical response after 3 days.

Recurrence Rates Following Treatment of Spinal Vascular Malformations: A Systematic Review and Meta-Analysis.

BACKGROUND: Spinal vascular malformations (SVMs), including arteriovenous malformations (AVMs) and arteriovenous fistulas (AVFs), are a varied group of vascular lesions that can be subclassified according to localization, vascular structure, and hemodynamics. Early intervention is necessary to halt progression of disease and minimize irreversible dysfunction. We sought to characterize initial treatment success and recurrence rates following interventional treatment of various types of SVMs. METHODS: A systematic review and meta-analysis were performed following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. SVMs were categorized into 4 groups: dural AVFs, perimedullary AVFs, intramedullary AVMs, and extradural-intradural AVMs (e.g., epidural, paraspinal). Initial occlusion, recurrence, and complication rates were compared using random-effects analysis. RESULTS: There were 112 manuscripts included, with a total of 5626 patients with SVM. For treatment, 2735 patients underwent endovascular embolization, 2854 underwent surgical resection, and 37 underwent stereotactic radiosurgery. The initial treatment success and overall recurrence rates following surgical resection of all SVMs were 89.5% (95% CI: 80.5%-98.5%) and 2.3% (95% CI: 0.9%-3.7%), respectively. Those rates following endovascular embolization were 55.9% (95% CI: 30.3%-81.5%) and 27.7% (95% CI: 11.2%-44.2%), respectively. Higher rates of initial treatment success and lower rates of recurrence with surgery were observed in all subtypes compared to embolization. Overall complication rates were higher after embolization for each of the SVM categories. CONCLUSIONS: Surgical resection of SVMs provided higher rates of initial complete occlusion and lower rates of recurrence than endovascular techniques. Attaining technical success through obliteration must still be weighed against clinical impact and natural history of the specific vascular malformation.

Evolution of open surgery for unruptured intracranial aneurysms over a fifteen year period-increased difficulty and morbidity.

OBJECTIVE: The approach to intervention for unruptured intracranial aneurysms (UIAs) remains controversial. Utilization of endovascular techniques for aneurysm repair increased dramatically during the last decade. We sought to analyze recent national trends for electively treated (open and endovascular) UIAs focusing on pre-existing patient disease burden and intervention modality selection. METHODS: The Nationwide Inpatient Sample (NIS) national database was used to identify patients with primary diagnosis codes of unruptured intracranial aneurysm between 1999 and 2014. Patients were dichotomized by intervention into endovascular or open surgical treatment. Analysis of pre-existing disease severity were calculated using the Elixhauser comorbidity index. Complications of combined peri-procedural stroke or death during admission and hospital length of stay were used as primary endpoints for comparison. RESULTS: The percent of total UIAs treated electively with open approach decreased from more than 95 % of cases in 1999 to less than 25 % in 2014. Patients undergoing clipping were 3 years younger than those in the endovascular group (p < 0.001). The rate of primary endpoint complications (stroke and death) and length of stay for open cases saw a decrease throughout the study but remained statistically higher when compared to the endovascular group over the study period (p < 0.001). Additionally, non-neurologic complications increased over the time period for open cases. The average preoperative co-morbid disease severity for all groups treated increased over this interval. Conversely, the relative volume of endovascular cases increased but the rate of complications and average group disease remained statistically lower than the surgical clipping group (p < 0.05). CONCLUSION: The percent of UIAs treated electively with open approach has decreased since 1999 with a concomitant increase in complication rate in particular compared to endovascular cases. However, the health characteristics of patients treated with surgical clipping show an increase in severity of pre-existing co-morbidities. Further research into factors contributing to this finding, including potential socioeconomic differences and changes in surgeon experience are needed.

Do Multidisciplinary Spine Conferences Alter Management or Impact Outcome?

BACKGROUND: Multidisciplinary spine conferences (MSCs) are a strategy for discussing diagnostic and treatment aspects of patient care. Although they are becoming more common in hospitals, literature investigating how they impact patient care and outcomes is scarce. The aim of this study is to examine the impact of MSCs on surgical management and outcomes in elective spine surgical care. METHODS: A systematic review of the literature was conducted to evaluate the impact of MSCs on patient management and outcomes. PubMed and Cochrane databases were searched using combinations and variations of search terms "Spine Conferences," "Multidisciplinary," and "Spine Team." RESULTS: The literature search yielded 435 articles, of which 120 were selected for full-text review. Four articles (N = 529 patients) were included. Surgical plans were discussed in 211 patients. The decision was altered to conservative treatment in 70 patients (33.17%) and a different surgical strategy in 34 patients (16.11%). The differences were significant in 2 studies (P < 0.05). A 51% reduction in 30-day complications rates was observed when MSC was implemented in patients with adult complex scoliosis. Other spinal disorders showed a 30-day complication rate between 0% and 14% after MSC. CONCLUSIONS: To our knowledge, this is the first systematic review of outcomes of MSCs in elective spine surgery and it confirms that MSCs impact management plan and outcomes. Consistent MSCs that include surgeons and nonsurgeons have the potential to enhance communication between specialists, standardize treatments, improve patient care, and encourage teamwork. More analysis is warranted to determine if patient outcomes are improved with these measures.

Is the routine use of systemic antibiotics after spine surgery warranted? A systematic review and meta-analysis.

PURPOSE: To determine whether the published literature supports the current practice of utilizing antibiotics postoperatively in spine surgery. METHODS: A systematic review from PubMed and Cochrane Central Register of Controlled trials databases was performed. Search terms used: "Antibiotic Prophylaxis"[Mesh], antibiotic*, antibacterial*, "Spine"[Mesh], "Surgical Procedures, Operative"[Mesh]. Only comparative, clinical studies were included. Those studies with surgical site infection (SSI) criteria that were not similar to the CDC definition were excluded. A meta-analysis for overall SSI was performed. A subgroup analysis was also performed to analyze the outcomes specifically on instrumented groups of patients. A random-effects model was used to calculate risk ratios (RR). Forest plots were used to display RR and 95% confidence intervals (CI). RESULTS: Thirteen studies were included (four Randomized-Controlled Trials, three prospective cohorts, and six retrospective). Three different perioperative strategies were used in the selected studies: Group 1: preoperative antibiotic administration (PreopAbx) versus PreopAbx and any type of postoperative antibiotic administration (Pre + postopAbx) (n = 6 studies; 7849 patients); Group 2: Pre + postopAbx ≤ 24 h versus Pre + postopAbx > 24 h (n = 6; 1982); and Group 3: Pre + postopAbx ≤ 48 h versus. Pre + postopAbx ≤ 72 h (n = 1; 502). The meta-analysis performed on Groups 1 and 2 did not show significant effects (RR = 1.27, 95% CI = 0.77, 2.09, and RR = 0.97, 95% CI = 0.64, 1.46, respectively). CONCLUSION: A meta-analysis and comprehensive review of the literature show that the routine use of postoperative antibiotics in spine surgery may not be effective in preventing surgical site infections.

Surgical management of dropped head syndrome: A systematic review.

Background: Dropped head syndrome (DHS) is uncommon and involves severe weakness of neck-extensor muscles resulting in a progressive reducible cervical kyphosis. The first-line management consists of medical treatment targeted at diagnosing underlying pathologies. However, the surgical management of DHS has not been well studied. Methods: Here, we systematically reviewed the PubMed and Cochrane databases for DHS using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. All relevant articles up to March 31, 2022, were analyzed. The patient had to be ≥18 years with DHS and had to have undergone surgery with outcomes data available. Outcomes measurements included neurological status, rate of failure (RF), horizontal gaze, and complications. Results: A total of 22 articles selected for this study identified 54 patients who averaged 68.9 years of age. Cervical arthrodesis without thoracic extension was performed in seven patients with a RF of 71%. Cervicothoracic arthrodesis was performed in 46 patients with an RF of 13%. The most chosen upper level of fusion was C2 in 63% of cases, and the occiput was included only in 13% of patients. All patients neurologically stabilized or improved, while 75% of undergoing anterior procedures exhibited postoperative dysphagia and/or airway-related complications. Conclusion: The early surgery for patients with DHS who demonstrate neurological compromise or progressive deformity is safe and effective and leads to excellent outcomes.

National trends in endovascular thrombectomy and decompressive craniectomy for acute ischemic stroke: A study using National Inpatient Sample data from 2006 to 2016.

BACKGROUND: Ischemic stroke is a frequently encountered neurologic process with wide-spanning impact. A dreaded complication is "malignant" cerebral edema, necessitating decompression to reduce herniation risk. Following the publication of several landmark trials in 2015, endovascular thrombectomy (EVT) with novel clot-removal devices has emerged as an effective treatment for proximal large vessel disease. Herein, we examine recent national trends in EVT and decompressive craniectomy (DC) rates for acute stroke. METHODS: National Inpatient Sample data were abstracted from 2006 to 2016. Primary outcomes were EVT and DC rates, compared using Cochrane-Armitage test of trend. Chi-square test was also used to compare data from 2015 to 2016. Secondary outcomes included inpatient mortality and home discharge rates. RESULTS: EVT rates steadily increased from 2006 to 2016, with most change occurring from 2014 to 2016 (1.36% in 2014, 2.29% in 2016). DC rates similarly increased from 2006 to 2015, though a sharp decline was observed in 2016 (0.42% in 2015, 0.22% in 2016). Test of trend from 2006 to 2016 for both variables was found to be statistically significant (p = 0.001); DC rate change from 2015 to 2016 was also statistically significant (p < 0.01). Mortality rate and home discharge rate steadily improved over the study period. CONCLUSIONS: Recent innovation in stroke treatment has led to increased EVTs. While DC rate initially followed this same trend, a significant decline was noted in 2016, around the time that wider adoption of novel EVT technologies were instituted in clinical practice.

Extraforaminal lumbar herniated disc mimicking foraminal tumor: Case report, literature review, and the role for minimally invasive approach for resection.

Herniated discs in the lumbar spine are common, however, extraforaminal disc herniations are less frequently encountered. Occasionally, rare disc herniations can mimic other pathologies such as nerve tumor. We present such case and a review of similar cases in the scientific literature. A 71-year-old male who presented with back pain and right-side sciatic pain. Magnetic resonance imaging revealed a fusiform enhancing 3 cm × 2 cm lesion that was concerning for a nerve sheath tumor. A minimally invasive lateral trans-psoas approach was performed for a biopsy that revealed disc fragments and a full resection was performed. The patient's symptoms improved at follow-up. Although uncommon, extraforaminal disc herniations can be mistaken for peripheral nerve tumors on imaging. The spine surgeon should remain vigilant about these entities and plan the surgical treatment accordingly.

Perioperative management of disease-modifying antirheumatic drugs for patients undergoing elective spine surgery: a systematic review.

BACKGROUND: In preparation for surgery, patients being treated with disease-modifying antirheumatic drugs (DMARDs) are recommended to either continue or withhold therapy perioperatively. Some of these drugs have known effects against bone healing, hence the importance of adequately managing them before and after surgery. OBJECTIVE: We aim to assess the current evidence for managing conventional synthetic and/or biologic DMARDs in the perioperative period for elective spine surgery. METHODS: A systematic review of four databases was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The included manuscripts were methodically scrutinized for quality, postoperative infections, wound healing characteristics, bone fusion rates, and clinical outcomes. RESULTS: Six studies were identified describing the management of conventional synthetic and/or biologic DMARDs. There were 294 DMARD-treated patients described undergoing various spine surgeries such as craniovertebral junction fusions. Three of the studies involved exclusive continuation of DMARDs in the perioperative window; one study involved exclusive discontinuation of DMARDs in the perioperative window; and two studies involved continuation or discontinuation of DMARDs perioperatively. Of patients that continued DMARDs in the perioperative period, 13/50 patients (26.0%) had postoperative surgical site infections or wound dehiscence, 2/19 patients (10.5%) had delayed wound healing, and 32/213 patients (15.0%) had secondary revision surgeries. A fusion rate of 14/19 (73.6%) was described in only one study for patients continuing DMARDs perioperatively. CONCLUSIONS: The available published data may suggest a higher risk of wound healing concerns and lower than average bone fusion, although this may be under-reported given the current state of the literature.

Current status of augmented reality in cerebrovascular surgery: a systematic review.

Augmented reality (AR) is an adjuvant tool in neuronavigation to improve spatial and anatomic understanding. The present review aims to describe the current status of intraoperative AR for the treatment of cerebrovascular pathology. A systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The following databases were searched: PubMed, Science Direct, Web of Science, and EMBASE up to December, 2020. The search strategy consisted of "augmented reality," "AR," "cerebrovascular," "navigation," "neurovascular," "neurosurgery," and "endovascular" in both AND and OR combinations. Studies included were original research articles with intraoperative application. The manuscripts were thoroughly examined for study design, outcomes, and results. Sixteen studies were identified describing the use of intraoperative AR in the treatment of cerebrovascular pathology. A total of 172 patients were treated for 190 cerebrovascular lesions using intraoperative AR. The most common treated pathology was intracranial aneurysms. Most studies were cases and there was only a case-control study. A head-up display system in the microscope was the most common AR display. AR was found to be useful for tailoring the craniotomy, dura opening, and proper identification of donor and recipient vessels in vascular bypass. Most AR systems were unable to account for tissue deformation. This systematic review suggests that intraoperative AR is becoming a promising and feasible adjunct in the treatment of cerebrovascular pathology. It has been found to be a useful tool in the preoperative planning and intraoperative guidance. However, its clinical benefits remain to be seen.

Complete seizure-free rates following interventional treatment of intracranial arteriovenous malformations: a systematic review and meta-analysis.

Seizures are common presenting symptoms of intracranial arteriovenous malformations (AVMs). This systematic review and meta-analysis aims to assess the current evidence regarding complete seizure freedom rates following surgical resection, stereotactic radiosurgery (SRS), and/or endovascular embolization of intracranial AVMs. A systematic review of PubMed, Ovid MEDLINE, and Ovid EMBASE was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Included manuscripts were methodically scrutinized for quality, spontaneous AVM-associated or hemorrhage-associated seizures, complete seizure-free rates following each interventional treatment, follow-up duration; determination methods of seizure outcomes, and average time-to-onset of recurrent seizures after each treatment. Manuscripts that described patients with nondisabling seizures or reduced seizure frequency in their seizure-free calculations were excluded. Seizure freedom rates following surgical resection, SRS, and endovascular embolization were compared via random-effect analysis. Thirty-four studies with a total of 1765 intracranial AVM patients presenting with spontaneous AVM-associated seizures and 408 patients presenting with hemorrhage-associated seizures were qualitatively analyzed. For patients presenting with AVM-associated seizures, the complete seizure-free rates were 73.0% (321/440 patients; 95% CI 68.8-77.1%) following surgical resection, 60.5% (376/622 patients; 95% CI 56.6-64.3%) following SRS, and 44.6% (29/65 patients; 95% CI 32.5-56.7%) following endovascular embolization alone. For patients presenting with either AVM-associated or hemorrhage-associated seizures, the complete seizure-free rates were 73.0% (584/800 patients; 95% CI 69.9-76.1%) following surgical resection, 46.4% (572/1233 patients; 95% CI 43.6-49.2%) following SRS, and 44.6% (29/65 patients; 95% CI 32.5-56.7%) following embolization. For patients presenting with either AVM-associated or hemorrhage-associated seizures, the overall improvements in seizure outcomes regardless of complete seizure freedom were 82.6% (661/800 patients; 95% CI 80.0-85.3%), 70.6% (870/1233 patients; 95% CI 68.0-73.1%), and 70.8% (46/65 patients; 95% CI 59.7-81.1%) following surgical resection, SRS, and embolization, respectively. No study reported information about the time-to-onset for recurrent seizures in any patient following treatment, as seizure outcomes were only described at the last follow-up visit. The available data suggests that surgical resection results in the highest rate of complete seizure freedom. The rate of seizure improvement following surgery increased further to 82.3% when including patients who had improved seizure frequency without achieving true seizure freedom. Complete seizure-free rates following SRS or embolization were more ambiguous and lower when compared to surgical resection. There is a need for high quality studies evaluating AVM treatment modalities and clearly defined seizure outcomes, as the current literature consists mostly of heterogenous patient populations.

Parkinson Disease, Dysphagia, and Cervical Spine Surgery.

STUDY DESIGN: An analysis of a National Database. OBJECTIVE: The objective of this study was to evaluate the rate of dysphagia for Parkinson disease (PD) patients undergoing cervical spine surgery for cervical myelopathy. SUMMARY OF BACKGROUND DATA: Cervical spondylotic myelopathy (CSM) is an increasingly common problem in the aging population. Several surgical options exist to treat this condition including anterior, posterior and combined surgical approaches. Each approach carries its own set of postoperative complications. Little is known of the of outcomes after cervical spine surgery in PD. MATERIALS AND METHODS: The National Inpatient sample was queried 1998 to 2016, all elective admissions with CSM were identified. Surgical treatments were identified as either: anterior cervical discectomy and fusion (ACDF), posterior laminectomies, posterior cervical fusion or combined anterior/posterior surgery. Preexisting PD was identified. Endpoints included mortality, length of stay (LOS), swallowing dysfunction measured by placement of feeding tube (NGT), and postprocedure pneumonia. RESULTS: A total of 73,088 patients underwent surgical procedures for CSM during the study period. Of those, 552 patients (7.5%) had concomitant PD. The most common procedure was ACDF. Patients with PD had a higher rate of dysphagia (NGT placement) after surgery compared with those without PD (P<0.001). Multiple regression analysis showed that PD patients had a higher risk of having NGT placement or developing pneumonia [odds ratio 2.98 (1.7-5.2), P<0.001] after surgery.Patients with PD who underwent ACDF, posterior laminectomies or posterior cervical fusion had a longer LOS compared with those who did not have PD (P<0.001). There was no difference in LOS for patients who underwent combined anterior/posterior surgery. Inpatient mortality was higher in patients with PD who underwent ACDF or combined surgery (P<0.001). CONCLUSIONS: While ACDF is the most commonly performed procedure for CSM in patients with PD, it is associated with longer LOS, higher incidence of postoperative dysphagia, and postprocedural pneumonia, as well as higher inpatient mortality compared with posterior cervical procedures. LEVEL OF EVIDENCE: Level III.

Three-Dimensional Printing in Neurosurgery Residency Training: A Systematic Review of the Literature.

BACKGROUND: The use of three-dimensional (3D) printing in neurosurgery has become more prominent in recent years for surgical training, preoperative planning, and patient education. Several smaller studies are available using 3D printing; however, there is a lack of a concise review. This article provides a systematic review of 3D models in use by neurosurgical residents, with emphasis on training, learning, and simulation. METHODS: A structured literature search of PubMed and Embase was conducted using PRISMA guidelines to identify publications specific to 3D models trialed on neurosurgical residents. Criteria for eligibility included articles discussing only neurosurgery, 3D models in neurosurgery, and models specifically tested or trialed on residents. RESULTS: Overall, 40 articles were identified that met inclusion criteria. These studies encompassed different neurosurgical areas including aneurysm, spine, craniosynostosis, transsphenoidal, craniotomy, skull base, and tumor. Most articles were related to brain surgery. Of these studies, vascular surgery had the highest overall, with 13 of 40 articles, which include aneurysm clipping and other neurovascular surgeries. Twenty-two articles discussed cranial plus tumor surgeries, which included skull base, craniotomy, craniosynostosis, and transsphenoidal. Five studies were specific to spine surgery. Subjective outcome measures of neurosurgical residents were most commonly implemented, of which results were almost unanimously positive. CONCLUSIONS: 3D printing technology is rapidly expanding in health care and neurosurgery in particular. The technology is quickly improving, and several studies have shown the effectiveness of 3D printing for neurosurgical residency education and training.

Utility of Augmented Reality and Virtual Reality in Spine Surgery: A Systematic Review of the Literature.

BACKGROUND: Augmented reality (AR), virtual reality (VR), and mixed reality (MR) are emerging technologies that are starting to be translated into clinical practice. Limited data are available regarding these tools in use during live surgery of the spine. Our objective was to systematically collect, analyze, and interpret the existing data regarding AR, VR, and MR use in spine surgery on living people. METHODS: A systematic review was conducted using the PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines. The PubMed, PubMed Central, Cochrane Reviews, and Embase databases were searched. Combinations and variations of the phrases "augmented reality," "virtual reality," and spine surgery using both "AND" and "OR" configurations were used to find relevant studies. The references of the included reports from the systematic review were also screened for possible inclusion as a part of a manual review. The included studies were full-text publications written in English that had included any spine surgery on live persons with the use of VR or AR. RESULTS: A total of 1566 unique reports were found, and 15 full-text publications met the criteria for the present study. The total number of patients from all studies was 241, with a weighted average age of 50.37 years. Surgical procedures using AR, VR, and/or MR were diverse and spanned from simple discectomy to intradural spinal tumor resection. All patients experienced improvement in their symptoms present at clinical presentation. The highest complication rate reported in the studies was 6.1% and was for suboptimal pedicle screw placement. No complications led to clinical sequelae. CONCLUSIONS: The systematically collected, analyzed, and interpreted data of existing peer-reviewed full-text articles showed favorable metrics regarding surgical efficacy, pedicle screw target accuracy, radiation exposure, clinical outcomes, and disability and pain for patients with spinal pathology treated with the help of AR, VR, and/or MR.

Is L5/S1 interbody fusion necessary in long-segment surgery for adult degenerative scoliosis? A systematic review and meta-analysis.

OBJECTIVE: There is no consensus regarding the best surgical strategy at the lumbosacral junction (LSJ) in long constructs for adult spinal deformity (ASD). The use of interbody fusion (IF) has been advocated to increase fusion rates, with additional pelvic fixation (PF) typically recommended. The actual benefit of IF even when extending to the pelvis, however, has not been vigorously analyzed. The goal of this work was to better understand the role of IF, specifically with respect to arthrodesis, when extending long constructs to the ilium. METHODS: A systematic review of the PubMed and Cochrane databases was performed to identify the relevant studies in English, addressing the management of LSJ in long constructs (defined as ≥ 5 levels) in ASD. The search terms used were as follows: "Lumbosacral Junction," "Long Constructs," "Long Fusion to the Sacrum," "Sacropelvic Fixation," "Interbody Fusion," and "Iliac Screw." The authors excluded technical notes, case reports, literature reviews, and cadaveric studies; pediatric populations; pathologies different from ASD; studies not using conventional techniques; and studies focused only on alignment of different levels. RESULTS: The PRISMA protocol was used. The authors found 12 retrospective clinical studies with a total of 1216 patients who were sorted into 3 different categories: group 1, using PF or not (n = 6); group 2, using PF with or without IF (n = 5); and group 3, from 1 study comparing anterior lumbar interbody fusion versus transforaminal lumbar interbody fusion. Five studies in group 1 and 4 in group 2 had pseudarthrosis rate as primary outcome and were selected for a quantitative analysis. Forest plots were used to display the risk ratio, and funnel plots were used to look at the risk of publication bias. The summary risk ratios were 0.36 (0.23-0.57, p < 0.001) and 1.03 (0.54-1.96, p = 0.94) for the PF and IF, respectively; there is a protective effect of overall pseudarthrosis for using PF in long constructs for ASD surgeries, but not for using IF. CONCLUSIONS: The long-held contention that L5/S1 IF is always advantageous in long-construct deformity surgery is not supported by the current literature. Based on the findings from this systematic review and meta-analysis, PF with or without additional L5/S1 interbody grafting demonstrates similar overall construct pseudarthrosis rates. The added risk and costs associated with IF, therefore, should be more closely considered on a case-by-case basis.