Learning Curves during Implementation of Robotic Stereotactic Surgery.

INTRODUCTION: Adoption of robotic techniques is increasing for neurosurgical applications. Common cranial applications include stereoelectroencephalography (sEEG) and deep brain stimulation (DBS). For surgeons to implement robotic techniques in these procedures, realistic learning curves must be anticipated for surgeons to overcome the challenges of integrating new techniques into surgical workflow. One such way of quantifying learning curves in surgery is cumulative sum (CUSUM) analysis. METHODS: Here, the authors present retrospective review of stereotactic cases to perform a CUSUM analysis of operative time for robotic cases at a single institution performed by 2 surgeons. The authors demonstrate learning phase durations of 20 and 16 cases in DBS and sEEG, respectively. RESULTS: After plateauing of operative time, mastery phases started at cases 132 and 72 in DBS and sEEG. A total of 273 cases (188 DBS and 85 sEEG) were included in the study. The authors observed a learning plateau concordant with change of location of surgery after exiting the learning phase. CONCLUSION: This study demonstrates the learning curve of 2 stereotactic workflows when integrating robotics as well as being the first study to examine the robotic learning curve in DBS via CUSUM analysis. This work provides data on what surgeons may expect when integrating this technology into their practice for cranial applications.

Intracerebral Transplantation of Autologous Mesenchymal Stem Cells Improves Functional Recovery in a Rat Model of Chronic Ischemic Stroke.

While treatments exist for the acute phase of stroke, there are limited options for patients with chronic infarcts and long-term disability. Allogenic mesenchymal stem cells (alloMSCs) show promise for the treatment of stroke soon after ischemic injury. There is, however, no information on the use of autologous MSCs (autoMSCs), delivered intracerebrally in rats with a chronic infarct. In this study, rats underwent middle cerebral artery occlusion (MCAO) to induce stroke followed by bone marrow aspiration and MSC expansion in a closed bioreactor. Four weeks later, brain MRI was obtained and autoMSCs (1 × 106, 2.5 × 106 or 5 × 106; n = 6 each) were stereotactically injected into the peri-infarct and compared to controls (MCAO only; MCAO + PBS; n = 6-9). Behavior was assessed using the modified neurological severity score (mNSS). For comparison, an additional cohort of MCAO rats were implanted with 2.5 × 106 alloMSCs generated from a healthy rat. All doses of autoMSCs produced significant improvement (54-70%) in sensorimotor function 60 days later. In contrast, alloMSCs improved only 31.7%, similar to that in PBS controls 30%. Quantum dot-labeled auto/alloMSCs were found exclusively at the implantation site throughout the post-transplantation period with no tumor formation on MRI or Ki67 staining of engrafted MSCs. Small differences in stroke volume and no differences in corpus callosum width were observed after MSC treatment. Stroke-induced glial reactivity in the peri-infarct was long-lasting and unabated by auto/alloMSC transplantation. These studies suggest that intracerebral transplantation of autoMSCs as compared to alloMSCs may be a promising treatment in chronic stroke.

Initial Heart Rate Predicts Functional Independence in Patients With Spinal Cord Injury Requiring Surgery: A Registry-Based Study in a Mature Trauma System Over the Past 10 Years.

STUDY DESIGN: Retrospective Cohort Study. OBJECTIVES: To determine the ability of early vital sign abnormalities to predict functional independence in patients with SCI that required surgery. METHODS: A retrospective analysis of data extracted from the Pennsylvania Trauma Outcome Study database. Inclusion criteria were patients >18 years with a diagnosis of SCI who required urgent spine surgery in Pennsylvania from 1/1/2010-12/31/2020 and had complete records available. RESULTS: A total of 644 patients met the inclusion criteria. The mean age was 47.1 ± 14.9 years old and the mean injury severity score (ISS) was 22.3 ± 12.7 with the SCI occurring in the cervical, thoracic, and lumbar spine in 61.8%, 19.6% and 18.0%, respectively. Multivariable logistic regression analyses for predictors of functional independence at discharge showed that higher HR at the scene (OR 1.016, 95% CI 1.006-1.027, P = .002) and lower ISS score (OR .894, 95% CI .870-.920, P < .001) were significant predictors of functional independence. Similarly, higher admission HR (OR 1.015, 95% CI 1.004-1.027, P = .008) and lower ISS score (OR .880, 95% CI 0.864-.914, P < .001) were significant predictors of functional independence. Peak Youden indices showed that patients with HR at scene >70 and admission HR ≥83 were more likely to achieve functional independence. CONCLUSIONS: Early heart rate is a strong predictor of functional independence in patients with SCI. HR at scene >70 and admission HR ≥83 is associated with improved outcomes, suggesting lack of neurogenic shock.

Lumbar Synovial Cysts-Should You Fuse or Not?

BACKGROUND: Spinal synovial cysts are lesions that most commonly occur in the lumbar region. The need for an instrumented spinal fusion in addition to lumbar decompression with removal of the synovial cyst is unknown. OBJECTIVE: To test the hypothesis that select patients who underwent decompression with instrumented fusion for lumbar synovial cysts would be less likely to have subsequent surgery (SS) in a 2-year period than patients treated with laminectomy alone. METHODS: This retrospective cohort study was performed using IBM MarketScan Commercial Claims and Encounters Database. Patients who had a lumbar synovial cyst diagnosis and laminectomy surgery with or without fusion surgery were included in this study. Patients were tracked for SS 2 years after surgery. Laminectomy patients were propensity score-matched to laminectomy with fusion (LF) patients using a 2:1 ratio. The log-rank test and Cox regression were used to compare the cumulative incidence of SS between groups. RESULTS: There were 7664 and 1631 patients treated with laminectomy and LF before matching. After matching, there were 2212 laminectomy and 1631 LF patients and patient characteristics were balanced. The 2-year incidence of recurrent SS was 3.1% ([CI]: 2.2%, 4.0%) and 1.7% (95% CI: 0.9%, 2.5%) laminectomy and LF, respectively. Compared with laminectomy, LF had a statistically significant lower risk of recurrent SS (hazard ratio: 0.56 [95% CI: 0.32-0.97]; P -value: .04). CONCLUSION: All patients who had concomitant lumbar fusion showed decreased chance of having a cyst- or noncyst-related recurrence SS when compared with all patients undergoing laminectomy alone, regardless of diagnosis at the time of SS.

Does Preoperative Opiate Choice Increase Risk of Postoperative Infection and Subsequent Surgery?

BACKGROUND: Opioids are commonly prescribed for chronic pain before spinal surgery and research has shown an increased rate of postoperative adverse events in these patients. OBJECTIVE: This study compared the incidence of 2-year subsequent surgical procedures and postoperative adverse events in patients undergoing lumbar fusion with or without 90-day preoperative opioid use. We hypothesized that patients using preoperative opioids would have a higher incidence of subsequent surgery and adverse outcomes. METHODS: A retrospective cohort study was performed using the Optum Pan-Therapeutic Electronic Health Records database including adult patients who had their first lumbar fusion between 2015 and 2018. The daily average preoperative opioid dosage 90 days before fusion was determined as morphine equivalent dose and further categorized into high dose (morphine equivalent dose >100 mg/day) and low dose (1-100 mg/day). Clinical outcomes were compared after adjusting for confounders. RESULTS: A total of 23,275 patients were included, with 2112 patients (10%) using opioids preoperatively. There was a significantly higher incidence of infection compared with nonusers (12.3% vs. 10.1%; P = 0.01). There was no association between subsequent fusion surgery (7.9% vs. 7.5%; P = 0.52) and subsequent decompression surgery (4.1% vs. 3.6%; P = 0.3) between opioid users and nonusers. Regarding postoperative infection risk, low-dose users showed significantly higher incidence (12.7% vs. 10.1%; P < 0.01), but high-dose users did not show higher incidence than nonusers (7.5% vs. 10.1%; P = 0.23). CONCLUSIONS: Consistent with previous studies, opioid use was significantly associated with a higher incidence of 2-year postoperative infection compared with nonuse. Low-dose opioid users had higher postoperative infection rates than did nonusers.

Increased Surgeon-specific Experience and Volume is Correlated With Improved Clinical Outcomes in Lumbar Fusion Patients.

STUDY DESIGN: The present study design was that of a single center, retrospective cohort study to evaluate the influence of surgeon-specific factors on patient functional outcomes at 6 months following lumbar fusion. Retrospective review of a prospectively maintained database of patients who underwent neurosurgical lumbar instrumented arthrodesis identified the present study population. OBJECTIVE: This study seeks to evaluate surgeon-specific variable effects on patient-reported outcomes such as Oswestry Disability Index (ODI) and the effect of North American Spine Society (NASS) concordance on outcomes in the setting of variable surgeon characteristics. SUMMARY OF BACKGROUND DATA: Lumbar fusion is one of the fastest growing procedures performed in the United States. Although the impact of surgeon-specific factors on patient-reported outcomes has been contested, studies examining these effects are limited. METHODS: This is a single center, retrospective cohort study analyzing a prospectively maintained database of patients who underwent neurosurgical lumbar instrumented arthrodesis by 1 of 5 neurosurgery fellowship trained spine surgeons. The primary outcome was improvement of ODI at 6 months postoperative follow-up compared with preoperative ODI. RESULTS: A total of 307 patients were identified for analysis. Overall, 62% of the study population achieved minimum clinically important difference (MCID) in ODI score at 6 months. Years in practice and volume of lumbar fusions were statistically significant independent predictors of MCID ODI on multivariable logistic regression ( P =0.0340 and P =0.0343, respectively). Concordance with evidence-based criteria conferred a 3.16 (95% CI: 1.03, 9.65) times greater odds of achieving MCID. CONCLUSION: This study demonstrates that traditional surgeon-specific variables predicting surgical morbidity such as experience and procedural volume are also predictors of achieving MCID 6 months postoperatively from lumbar fusion. Independent of surgeon factors, however, adhering to evidence-based guidelines can lead to improved outcomes.

Accuracy and efficiency using frameless transient fiducial registration in stereoelectroencephalography and deep brain stimulation.

OBJECTIVE: Stereotactic surgical methods continue to advance technologically. Frameless transient fiducial registration (FTFR) systems have been developed and avoid the need to move or position a patient in a frame after already receiving registration imaging. One such system, Neurolocate, has recently become available as a robotic attachment for the Neuromate stereotactic robot. This study is the largest in the literature to evaluate the accuracy of frameless registration using Neurolocate versus frame-based registration (FBR) methods in both deep brain stimulation (DBS) and stereoelectroencephalography (SEEG). Additionally, the authors sought to reevaluate factors affecting accuracy in both procedures. METHODS: This study was a retrospective chart and imaging review of 88 consecutive procedures (involving 621 electrodes) implanting either DBS or SEEG at the authors' institution over a 5-year period from March 2015 to March 2020. Registration duration, radial target entry point, and Euclidean target implantation accuracies, as well as factors affecting accuracy, were recorded for each patient. RESULTS: SEEG procedures included 38 patients and 525 implanted electrodes (294 using FBR and 231 using FTFR). DBS procedures included 50 patients and 96 implanted electrodes (65 using FBR and 31 using FTFR). Overall, FTFR registration was significantly more accurate (median 0.1 mm, IQR 0-0.4 mm) compared with FBR (median 1.3 mm, IQR 0.9-1.5 mm; p = 0.04). Likewise, FTFR had a significantly shorter duration of registration (median 84 minutes, IQR 77.3-95.3 minutes) when compared with FBR (median 110.5 minutes, IQR 107.3-138 minutes; p = 0.02). No significant differences were found when examining the radial entry point and Euclidean target implantation errors of each method. CONCLUSIONS: FTFR with the Neurolocate system represents a technique that may decrease operative time while maintaining the high accuracy previously demonstrated by other stereotactic methods, despite an initial surgeon learning curve. It should be investigated in future studies to continue to improve stereotactic accuracies in neurosurgery.

Case report: The promising application of dynamic functional connectivity analysis on an individual with failed back surgery syndrome.

Failed back surgery syndrome (FBSS), a chronic neuropathic pain condition, is a common indication for spinal cord stimulation (SCS). However, the mechanisms of SCS, especially its effects on supraspinal/brain functional connectivity, are still not fully understood. Resting state functional magnetic resonance imaging (rsfMRI) studies have shown characteristics in patients with chronic low back pain (cLBP). In this case study, we performed rsfMRI scanning (3.0 T) on an FBSS patient, who presented with chronic low back and leg pain following her previous lumbar microdiscectomy and had undergone permanent SCS. Appropriate MRI safety measures were undertaken to scan this subject. Seed-based functional connectivity (FC) was performed on the rsfMRI data acquired from the FBSS subject, and then compared to a group of 17 healthy controls. Seeds were identified by an atlas of resting state networks (RSNs), which is composed of 32 regions grouped into 8 networks. Sliding-window method and k-means clustering were used in dynamic FC analysis, which resulted in 4 brain states for each group. Our results demonstrated the safety and feasibility of 3T MRI scanning in a patient with implanted SCS system. Compared to the brain states of healthy controls, the FBSS subject presented very different FC patterns in less frequent brain states. The mean dwell time of brain states showed distinct distributions: the FBSS subject seemed to prefer a single state over the others. Although future studies with large sample sizes are needed to make statistical conclusions, our findings demonstrated the promising application of dynamic FC to provide more granularity with FC changes associated with different brain states in chronic pain.

Does the Number of Levels of Decompression Have an Impact on the Clinical Outcomes of Patients With Lumbar Degenerative Spondylolisthesis: A Retrospective Study in Single-Level Fused Patients.

Introduction The American Association of Neurological Surgeons (AANS) and the Congress of Neurological Surgeons (CNS) 2014 lumbar fusion guidelines for stenosis with degenerative spondylolisthesis (DS) support surgical decompression and fusion as an effective treatment option for symptomatic stenosis associated with DS. The association between the number of levels decompressed in patients with single-level fusion and clinical outcomes has never been published. Methods A retrospective analysis of a single-center, prospectively collected database was performed on 77 patients to compare the effect of the number of decompression levels in patients that received single-level fusion surgery. A total of 77 patients met the criteria. Group one had one level decompressed, group two had two levels decompressed, and group three had three or four levels decompressed. All patients received lumbar fusion surgery at a single spinal level. Outcomes at six months included: Substantial Clinical Benefit (SCB) (ΔODI ≥ 10 points); Minimal Clinically Important Difference (MCID) (ΔODI ≥ 5); no MCID (ΔODI <5 points). Student's t-tests, one-way analysis of variance (ANOVA), and post hoc comparison using unpaired two-tailed student's t-test with Holm-Bonferroni correction were performed. p -values were ranked from smallest to largest, and alpha level adjustments were made.  Results A sub-analysis of each group's clinical outcomes showed that patients with two levels decompressed reached greater clinical outcomes. SCB was obtained by approximately 60% (group one: 12.5% vs. group three: 40%) of the patients. A total of 77.6% (38/49) achieved MCID (group one: 62.5% vs. group three: 55%). Single-level fused patients with two levels of decompression showed an improvement of 48% from baseline ODI, as opposed to group one: 17.85% and group three: 21.1%. Patients belonging to group two showed the lowest rate of no improvement. Baseline ODI scores were similar upon presentation (p=0.46), and the difference was found among groups after six months of follow-up (p=0.009). Post hoc comparison showed statistical significance in the comparison between group two and group three (p=0.009, alpha value: 0.017). Conclusion The addition of more than two levels of decompression to single-level fused patients might be associated with poor clinical outcomes and spinal instability.

Incidence of Pseudarthrosis and Subsequent Surgery After Cervical Fusion Surgery: A Retrospective Review of a National Health Care Claims Database.

BACKGROUND: Cervical pseudarthrosis is a postoperative adverse event that occurs when a surgically induced fusion fails to establish bone growth connecting the 2 regions. It has both clinical and financial implications and may result in significant patient morbidity; it continues to be one of the leading causes of pain after surgery. METHODS: A retrospective longitudinal cohort study was performed. Patients in the IBM MarketScan Commercial Claims and Encounters (CCAE) database, 18-64 years old, who underwent elective cervical fusions during 2015-2019 were included. Patients with trauma, infection, or neoplasm were excluded. Patients were followed for 2 years from surgical fusion for occurrence of pseudarthrosis. After pseudarthrosis, subsequent surgery was documented, and cumulative incidence curves, adjusted for patient/procedure characteristics, with 95% confidence intervals (CIs) were generated. Risk factors were evaluated with multivariable Cox regression analysis. RESULTS: The cohort included 45,584 patients. The 1-year and 2-year incidence of pseudarthrosis was 2.0% (95% CI, 1.9%-2.2%) and 3.3% (95% CI, 3.1%-3.5%), respectively. Factors significantly associated with increased risk of pseudarthrosis were female gender, current/previous substance abuse, previous spinal pain in the cervical/thoracic/lumbar spine, and Elixhauser score ≥5. Factors significantly associated with decreased risk of pseudarthrosis were anterior cervical approach, use of an interbody cage, and 2-level or 3-level anterior instrumentation. The 1-year and 2-year incidence of subsequent surgery in patients with pseudarthrosis was 11.7% (95% CI, 9.6%-13.7%) and 13.8% (95% CI, 11.5%-16.2%), respectively. CONCLUSIONS: Cervical pseudarthrosis and subsequent surgery still occur at a low rate. Surgical factors such as anterior approach, interbody cage use, and anterior instrumentation may reduce pseudarthrosis risk.

Digital Subtraction Angiography May Reduce the Rate of Radiographic Hemorrhage in Stereoelectroencephalography.

OBJECTIVE: To study the effect of preoperative digital subtractive angiography (DSA) for planning stereoelectroencephalography (sEEG) electrode trajectories on the rate of postoperative radiographic hemorrhage. METHODS: A retrospective, single-center observational study was conducted examining every sEEG implantation consisting of 72 implantations of 1028 total electrodes with each patient having received a preoperative planning DSA. Postimplant imaging was analyzed for the presence of hemorrhage. Postoperative computed tomography were then merged and coregistered with preoperative DSA to determine if a collision or near-miss (within 1 mm) occurred between the perihemorrhage electrodes and a vessel. Statistical analysis was then conducted. RESULTS: Six patients (8.3%) had hemorrhage seen on computed tomography with a bleeding rate of 0.6% per electrode. Five patients were asymptomatic (6.94%) and one symptomatic (1.39%). One patient suffered permanent neurologic deficits, and there have been zero deaths. In the hemorrhage group, there were 3 subdural, 2 subarachnoid, and 2 intraparenchymal. All subdural and subarachnoid hemorrhages had electrodes that were found to collide or near-miss a vessel when compared with preoperative DSA. Half of the intraparenchymal hemorrhages had no obvious vessel in proximity to the electrodes. Our data show that preoperative DSA is a viable screening test and portends a 94.7% sensitivity and 53.6% specificity for predicting post operative radiographic hemorrhage. CONCLUSIONS: Analysis of our sEEG series reveals a substantially lower rate of postimplant hemorrhage when compared with the recent cohort studies. Our data indicate that preoperative DSA may be efficacious in reducing the incidence of sEEG postimplant hemorrhages.

Patient-Reported Outcomes for Lumbar Fusion in Patients with Previously Treated Cervical Myelopathy.

BACKGROUND: Patients with a history of surgically treated cervical myelopathy and lumbar pathology requiring fusion present complex challenges, and literature describing patient-reported outcomes in this cohort beyond patients with tandem spinal stenosis is sparse. This has led to unclear guidelines in the literature. We present the first dataset comparing patient-reported outcomes for lumbar fusion in patients with isolated lumbar pathology versus patients with a history of surgically treated cervical myelopathy. METHODS: In this retrospective cohort study of a prospectively collected lumbar fusion database, variables of interest included demographics, comorbidities, type and levels of fusion, Oswestry Disability Index (ODI), and minimal clinically important difference. RESULTS: Of 325 patients identified, 309 met inclusion criteria. Of these, 29 patients had previous cervical surgery to address cervical myelopathy. Median time between cervical and lumbar surgery was 4.0 years (range, 0.3-19.7). There was no statistical difference in preoperative ODI score (24.8 vs. 25.6, P = 0.687), 6-month postoperative ODI score (17.3 vs. 18.7, P = 0.459), change in ODI score (7.5 vs. 6.9, P = 0.673), or minimal clinically important difference for ODI score (62.1% vs. 58.6%, P = 0.710) in patients who had undergone cervical surgery versus patients who had not. CONCLUSIONS: Patients with a history of previously treated cervical myelopathy have a similar rate of clinically relevant improvement after lumbar fusion compared with patients without such history. As such, these patients appear to benefit from lumbar fusion surgery to the same degree as patients without a history of surgically treated cervical myelopathy.

A Review of Endoscopic Spine Surgery: Decompression for Radiculopathy.

PURPOSE OF REVIEW: With this manuscript the authors sought to write a succinct review of the origins, as well as the latest advancements in endoscopic spine surgery to serve as a reference frame for physicians looking to learn this approach. RECENT FINDINGS: At its infancy, the indications for posterolateral and transforaminal endoscopic decompression remained narrow, which prevented the procedure from gaining rapid traction during those days. However, more recently the tides have turned and an increasing number of surgeons are starting to adopt this technique given all its advantages. With the advent of higher quality camera systems and instruments, indications to use a minimally invasive option have gotten significantly broader. The most basic indication for the use of this technology is a soft disc herniation causing compromise of a neural structure that has failed to be managed successfully with non-surgical therapies. The use of endoscopic techniques provides significant advantages to patient outcomes and patient recovery. Endoscopic procedures should not be used as a blanket approach to nerve root decompression, as they certainly have limitations. Most contraindications to this procedure are relative and serve mostly as points to consider when selecting the methods to address neural compression. As these techniques become more widely accepted, we expect its reach and indications to continue to broaden and diversify. The full integration of navigation technologies will likely leapfrog this procedure into the mainstream use.

The Impact of Intraoperative Image-Guidance Modalities and Neurophysiologic Monitoring in the Safety of Sacroiliac Fusions.

STUDY DESIGN: Retrospective observational cohort. OBJECTIVE: A review of efficiency and safety of fluoroscopy and stereotactic navigation system for minimally invasive (MIS) Sacroiliac (SI) fusion through a lateral technique. METHODS: Retrospective analysis of an observational cohort of 96 patients greater than 18 years old, that underwent MIS SI fusion guided by fluoroscopy or navigation between January 2013 and April 2020 with a minimum of 3 months follow-up. Intraoperative neuromonitoring (IONM) with a variable combination of electromyography (EMG), somatosensory evoked potentials (SSEPs) and motor evoked potentials (MEPs) was also utilized. RESULTS: The overall complication rate in the study was 9.4%, and there was no difference between the fluoroscopy (10.1%), and navigation groups (8%). Neurological complication rate was 2.1%, without a significant difference between both intraoperative guidance modality groups (p = 0.227). There was a significant difference between the modalities of IONM used and the occurrence of neurological injury (p = 0.01).The 2 patients who had a neurological complication postoperatively were monitored only with EMG and SSEP, but none of the patients (n = 76) in which MEPs were utilized had neurologic complication. The mean pain improvement 3 months after surgery was greater in the navigation group (2.44 ± 2.72), but was not statistically different than the improvement in the fluoroscopy group (1.90 ± 2.07) (p = 0.301). CONCLUSIONS: No difference in the safety of the procedure was found between the fluoroscopy and the stereotactic navigation techniques. The contribution of the IONM to the safety of SI fusions could not be determined, but the data indicates that MEPs provide the highest level of sensitivity.

Combined Anterior Osteophytectomy and Cricopharyngeal Myotomy for Treatment of DISH-Associated Dysphagia.

STUDY DESIGN: Retrospective observational case series. OBJECTIVE: To assess the outcome of patients with diffuse idiopathic skeletal hyperostosis (DISH) with dysphagia who underwent cricopharyngeal myotomy (CPM) in conjunction with anterior osteophytectomy (OP). METHODS: This is a retrospective observational study of 9 patients that received combined intervention by neurosurgeons and otolaryngologists. Inclusion criteria for surgery consisted of patients who failed to respond to conservative treatments for dysphagia and had evidence of both upper esophageal dysfunction and osteophyte compression. We present the largest series in literature to date including patients undergoing combined OP and CPM. RESULTS: A total of 88.9% (8/9) of the patients who underwent OP and CPM showed improvement in their symptoms. Of the aforementioned group, 22.2% of these patients had complete resolution of their symptoms, 11.1% did not improve, and only 2 patients showed recurrence of their symptoms. None of the patients in whom surgery was performed required reoperation or suffered serious complication related to the surgical procedures. CONCLUSION: Based on the literature results, high rate of improvements in dysphagia, and low rate of complications, combined OP and CPM procedures may be beneficial to a carefully selected group of patients.

Costs Associated with Laser Interstitial Thermal Therapy Are Lower Than Anterior Temporal Lobectomy for Treatment of Temporal Lobe Epilepsy.

BACKGROUND: Laser interstitial thermal therapy (LITT) is a minimally invasive alternative to anterior temporal lobectomy (ATL) for treatment of temporal lobe epilepsy. It has gained popularity as familiarity with technique increases and outcomes are better characterized. There has been no direct cost comparison between the 2 techniques in literature to date. The current study directly compares hospital costs associated with LITT with those of ATL patients and analyzes the factors potentially responsible for those costs. METHODS: Patients who underwent ATL (27) and LITT (15) were retrospectively reviewed for total hospital costs along with demographic, surgical, and postoperative factors potentially affecting cost. T-tests were used to compare costs and independent linear regressions, and hierarchical regressions were used to examine predictors of cost for each procedure. RESULTS: Mean hospital costs of admission for single-trajectory LITT ($104,929.88) were significantly less than for ATL ($134,980.04) (P = 0.001). In addition, length of stay, anesthesia costs, operative room costs, and postoperative hospitalization costs were all significantly lower in LITT. CONCLUSIONS: Given the minimally invasive nature of LITT, it is associated with shorter length of stay and lower hospital costs than ATL in the first head-to-head comparison of procedural costs in literature to date. Long-term efficacy as it relates to these costs associated with LITT and ATL should be further investigated to better characterize the utility of LITT in temporal lobe epilepsy patients.

Single-Center Retrospective Analysis of Device-Related Complications Related to Dorsal Root Ganglion Stimulation for Pain Relief in 31 Patients.

INTRODUCTION: Dorsal root ganglion (DRG) stimulation is a form of neuromodulation used to treat neuropathic pain due to a myriad of etiologies. Though this relatively new therapy has been shown to be quite effective, complications associated with the implantation of this therapy have not been well documented. OBJECTIVES: The primary objective of this study was to describe the device-related complications associated with DRG stimulator implantations. MATERIALS AND METHODS: This was a single-center retrospective analysis of 31 patients who underwent full implantation of neuromodulation hardware marketed for DRG stimulation. The predefined endpoints included device-related complications associated with DRG implantations, such as hardware failure, explantation procedures, and revision surgery. Additional endpoints included percentage of patients receiving therapy and pain as measured using the visual analog scale (VAS) pain scale at initial, six-month, and 12-month follow-up after hardware implantation. RESULTS: Thirty-one patients were included out of 42 patients trialed. Baseline VAS in patients was 7.7 (31 patients). At initial follow-up, six-month follow-up, and one-year follow-up, VAS scores were 4.7 (31 patients), 5.3 (20 patients), and 5.5 (13 patients), respectively. Paired t-test between preoperative VAS (mean 7.3) and one-year follow-up VAS (5.5) demonstrated statistical significance (p = 0.027). At initial, six-month, and one-year follow-up, 30/31 (97%), 19/24 (79%), and 18/23 (78%) patients were confirmed to be receiving DRG stimulation therapy after permanent implant. Of the 31 patients who were implanted with a permanent system, 8 (26%) were explanted and an additional 10 (29%) required revision surgery. CONCLUSION: In this study, we examine the various device-related complications associated with DRG stimulation requiring repeat surgery. High rates of hardware failure, revision surgery, and explantation of stimulators illustrate the need for hardware optimization to improve patient outcomes.

Clinical outcomes in revision lumbar spine fusions: an observational cohort study.

OBJECTIVE: The authors compared primary lumbar spine fusions with revision fusions by using patient Oswestry Disability Index (ODI) scores to evaluate the impact of the North American Spine Society (NASS) evidence-based medicine (EBM) lumbar fusion indications on patient-reported outcome measures of revision surgeries. METHODS: This study was a retrospective analysis of a prospective observational cohort of patients who underwent elective lumbar fusion between January 2018 and December 2019 at a single quaternary spine surgery service and had a minimum of 6 months of follow-up. A prospective quality improvement database was constructed that included the data from all elective lumbar spine surgeries, which were categorized prospectively as primary or revision surgeries and EBM-concordant or EBM-discordant revision surgeries based on the NASS coverage EBM policy. In total, 309 patients who met the inclusion criteria were included in the study. The ODIs of all groups (primary, revision, revision EBM concordant, and revision EBM discordant) were statistically compared. Differences in frequencies between cohorts were evaluated using chi-square and Fisher's exact tests. The unpaired 2-tailed Student t-test and the Mann-Whitney U-test for nonparametric data were used to compare continuous variables. Logistic regression was performed to determine the associations between independent variables (surgery status and NASS criteria indications) and functional outcomes. RESULTS: Primary lumbar fusions were significantly associated with improved functional outcomes compared with revisions, as evidenced by ODI scores (OR 1.85, 95% CI 1.16-2.95 to achieve a minimal clinically important difference, p = 0.01). The percentage of patients whose functional status had declined at the 6-month postoperative evaluation was significantly higher in patients who had undergone a revision surgery than in those who underwent a primary surgery (23% vs 12.3%, respectively). An increase in ODI score, indicating worse clinical outcome after surgery, was greater in patients who underwent revision procedures (OR 2.14, 95% CI 1.17-3.91, p = 0.0014). Patients who underwent EBM-concordant revision surgery had significantly improved mean ODI scores compared with those who underwent EBM-discordant revision surgery (7.02 ± 5.57 vs -4.6 ± 6.54, p < 0.01). CONCLUSIONS: The results of this prospective quality improvement program investigation illustrate that outcomes of primary lumbar fusions were superior to outcomes of revisions. However, revision procedures that met EBM guidelines were associated with greater improvements in ODI scores, which indicates that the use of defined EBM guideline criteria for reoperation can improve clinical outcomes of revision lumbar fusions.

Independent Predictors of Revision Lumbar Fusion Outcomes and the Impact of Spine Surgeon Variability: Does It Matter Whether the Primary Surgeon Revises?

BACKGROUND: There is a paucity of information regarding treatment strategies and variables affecting outcomes of revision lumbar fusions. OBJECTIVE: To evaluate the influence of primary vs different surgeon on functional outcomes of revisions. METHODS: All elective lumbar fusion revisions, March 2018 to August 2019, were retrospectively categorized as performed by the same or different surgeon who performed the primary surgery. Oswestry Disability Index (ODI) and clinical variables were collected. Multiple logistic regression identified multivariable-adjusted odds ratio (OR) of independent variables analyzed. RESULTS: Of the 130 cases, 117 (90%) had complete data. There was a slight difference in age in the same (median: 59; interquartile range [IQR], 54-66) and different surgeon (median: 67; IQR, 56-72) groups (P = .02); all other demographic variables were not significantly different (P > .05). Revision surgery with a different surgeon had an ODI improvement (median: 8; IQR, 2-14) greater than revisions performed by the same surgeon (median: 1.5; IQR, -3 to 10) (P < .01). Revisions who achieved minimum clinically important difference (MCID) performed by different surgeon (59.7%) were also significantly greater than the ones performed by the same surgeon (40%) (P = .042). Multivariate analysis demonstrated that a different surgeon revising (OR, 2.37; [CI]: 1.007-5.575, P = .04) was an independent predictor of MCID achievement, each additional 2 years beyond the last surgery conferred a 2.38 ([CI]: 1.36-4.14, P < .01) times greater odds of MCID achievement, and the anterior lumbar interbody fusion approach decreased the chance of achieving MCID (OR, 0.19; [CI]: 0.04-0.861, P = .03). CONCLUSION: All revision lumbar spinal fusion approaches may not achieve the same outcomes. This analysis suggests that revision surgeries may have better outcomes when performed by a different surgeon.