bluuebunny/crossref_metadata_2025 huggingface dataset:
349 Brain Functional Imaging of Pain States Using Resting-State fMRI and Multi-Delay PCASL in Chronic Low-Back Pain Patients Implanted With Thoracic Spinal Cord Stimulation
Authors: Oghli Yazan Shamli , Ashok Arjun Balaji , Ailes Isaiah , Syed Mashaal , Kang KiChang , Naghizadehkashani Sara , Fayed Islam , Matias Caio M. , Mohamed Feroze , Krisa Laura , Alizadeh Mahdi
Published: March 2024

INTRODUCTION:

A treatment of chronic low-back pain is implantation of a thoracic spinal cord stimulator (tSCS), which has been shown to reduce pain. The functional changes in pain processing regions of the brain as assessed by resting-state fMRI and multi-delay pseudocontinuous arterial spin labeling (PCASL) have never been studied.

METHODS:

PCASL data based on 5 post-label delays (0.5–2.5s) as well as rsfMRI were acquired in five patients (1F) post-tSCS with cLBP and five healthy subjects (2F). Patient MRI scans were taken post-implantation with the SCS device turned off. Three PCASL measures and four rsfMRI measures were derived and normalized into MNI space and smoothed. Averaged values for each measure from the pain ROI atlas were extracted and compared between patients and controls. Statistics were conducted following Box-Cox transformation of data.

RESULTS:

Arterial transit time derived from PCASL showed a significant difference in the OFC, SMA, and PSG of patients, but other ASL measures showed no effect. Several regions across the rs-fMRI measures showed significant differences, including those involved in cognition (DLPFC, PCC), and pain processing (PSG) and sensation (S2).

CONCLUSIONS:

Functional imaging showed that cLBP patients treated with SCS display differences in resting-state function and brain perfusion across several pain regions of the brain. These areas are mainly part of the cognitive and behavioral components of the pain circuitry.
351 Comparing SCS and Conventional Medical Management in Patients With No Prior Back Surgery (SOLIS RCT)
Authors: North James , Paez Julio , Calodney Aaron K. , Loudermilk Eric , McCormick Zachary , Trainor Drew , Noles John , Yang Michael Ishu , Phillips Gregory , Wilson Derron , Rosen Steven , Guirguis Maged , Chen Lilly , Jain Roshini
Published: March 2024

INTRODUCTION:

Spinal Cord Stimulation (SCS) as a treatment for chronic pain has been historically designated for patients who have had at least one prior spinal surgery. Modern SCS devices though now offer more novel technological capabilities and neurostimulative approaches than older-generational SCS systems.

METHODS:

This is a prospective, multicenter, randomized controlled trial (RCT) that compares therapeutic effectiveness of SCS versus CMM only, in patients with chronic low back and/or leg pain with no prior spinal surgery (SOLIS, Clinicaltrials.gov: NCT04676022). Enrolled NSBP patients are randomized to SCS combined with CMM (SCS + CMM arm) or a CMM-only arm. Those receving SCS are implanted with a multimodal system capable of engaging multiple mechanisms of action (Wavewriter Systems, Boston Scientific). Key inclusion criteria include diagnosis of chronic low back pain, with or without leg pain, for =6 months, and documented care of chronic pain for =90 days. The primary endpoint is responder rate (=50% reduction in pain) with no increase in baseline opioid medications to treat pain at 3-months following treatment activation.

RESULTS:

The primary endpoint (p < 0.0001) was met based on a prespecified cohort of 60 treatment-activated subjects. This analysis demonstrated that multimodal SCS combined with CMM was superior to CMM alone (p < 0.0001) in treating NSBP patients at 3-months follow-up (SCS: 88% versus CMM: 8%). Additionally, a 27-point reduction in Oswestry Disability Index score (improvement in disability) was noted in the SCS group versus a 6-point reduction in the CMM group.

CONCLUSIONS:

The data obtained in this RCT demonstrates that utilization of multimodal SCS provides for superior outcomes when compared to use of CMM alone for treatment of NSBP.
359 Low-Intensity Focused Ultrasound to Human Dorsal Anterior Cingulate Cortex and Insula Attenuates Measures of Central Sensitization
Authors: In Alexander , Strohman Andrew , Legon Wynn
Published: March 2024

INTRODUCTION:

Central sensitization is the abnormal amplified response to pain and is associated with chronic pain. Increased insula and dorsal anterior cingulate cortex (dACC) activity is associated with central sensitization. Low-intensity focused ultrasound (LIFU) is a novel form of non-invasive neuromodulation that can precisely target the anterior insula (AI), posterior insula (PI) and dACC.

METHODS:

N = 18 healthy participants underwent conditioned pain modulation (CPM) and temporal summation of pain (TSP) tasks before and after 10 minutes of LIFU or sham stimulations. For CPM, the conditioning stimulus (CS) was a cold pressor test to the left hand and the test stimulus (TS) was a brief transient heat stimulus to the dorsum of the right hand. For TSP, 10 transient heat stimuli (>0.33 Hz) were administered to the dorsum of the right hand. The primary outcome measure for both tasks was perceived pain ratings (0-9). Electrodermal response and electrocardiogram was collected to evaluate the effect of LIFU on autonomic reactivity.

RESULTS:

LIFU to PI increased CPM 0.5 ± 0.181 compared to sham (p = 0.024). LIFU to PI also significantly reduced perceived pain during the TSP task compared to sham (p < 0.001). We also found a significant difference between dACC and sham conditions during TSP by -0.55 ± 0.05 (p < 0.001). LIFU to the AI increases frequency domain measures of heart-rate variability.

CONCLUSIONS:

LIFU to the insula and dACC affects pain processing in measures of central sensitization. This demonstrates the neuromodulation abilities of LIFU and is a promising tool to develop noninvasive clinical therapies for chronic pain conditions.
360 Diffusion Imaging-Derived Structural Changes in Cerebral Pain Regions of Chronic Low-Back Pain Patients Implanted With Thoracic Spinal Cord Stimulation
Authors: Oghli Yazan Shamli , Ashok Arjun Balaji , Ailes Isaiah , Syed Mashaal , Kang KiChang , Naghizadehkashani Sara , Fayed Islam , Matias Caio M. , Mohamed Feroze , Krisa Laura , Alizadeh Mahdi
Published: March 2024

INTRODUCTION:

Thoracic spinal cord stimulation (tSCS) is an effective treatment of chronic low-back pain (cLBP). Although diffusion imaging has been conducted in this group of patients, the study of diffusion-derived structural imaging of regions involved in pain processing has not been conducted.

METHODS:

Diffusion-weighted imaging scans were acquired in five patients (1 female) post-tSCS with cLBP and five healthy subjects (2 female). Patient MRI scans were taken post-implantation with the SCS device turned off during the MRI session. Four DTI maps and four MAP maps were derived and normalized into MNI space and smoothed. DTI and MAP values for each measure from the pain ROI atlas were extracted and compared between patients and controls.

RESULTS:

Statistically significant differences were found in regions involved with sensory processing of pain (ASG, PSG) as well as affective pain experience (ACC) across the DTI measures. MAP measures showed significance across five ROIs involved with sensory processing of pain, affective pain experience, and fear response (AMYG).

CONCLUSIONS:

Diffusion-derived structural imaging of pain regions suggests that cLBP patients receiving SCS have differences in diffusion imaging-derived structural parameters involved with pain processing, cognition, and fear response.
367 Postoperative Opioid Use Among Cannabis Users Following One-, Two-, and Three-Level Lumbar Fusions
Authors: Khalid Syed Ibad , Mirpuri Pranav , King Patrick J. , Mehta Ankit Indravadan , Adogwa Owoicho
Published: March 2024

INTRODUCTION:

Opioids are critical for pain management following spine surgery. Given the devastating consequences of the opioid epidemic, strategies to minimize dosing and chronic use of opioids should be developed.

METHODS:

This retrospective study used medical coding to identify patients who had undergone 1-3 level lumbar fusions between January 2010 and October 2020. Propensity score matching based on demographics and comorbidities created two equal cohorts concerning cannabis use history. Opioid utilization rates (morphine milligram equivalents/day) and overuse rates six months after the index procedure were assessed.

RESULTS:

1,216 patients were matched and distributed equally into cannabis and non-cannabis user cohorts. Lower rates of opioid utilization were found among cannabis users versus control as early as two months after fusion (47.7% versus 41.1%, p < 0.05), a relationship which persisted at six months as well (46.2% versus 37.7%, p < 0.01). Lower rates of high-dose opioid utilization (=100 MME per day) were also found in the cannabis user cohort during the initial period of 14-30 days following surgery (6.91% versus 3.79%, p < 0.05). This relationship also approached significance 121-150 days after surgery (3.13% versus 1.32%, p = 0.051).

CONCLUSIONS:

In this study, patients with a history of cannabis use were less likely to use opioids as early as two months postoperatively. They had lower rates of high-dose opioid utilization in the immediate postoperative period. While this study cannot say whether cannabis is a beneficial adjunctive therapy for pain, clearly physicians should be aware of their patients’ cannabis use patterns to provide appropriate dose titration over time.
370 Is There an Optimal Surgical Approach in Degenerative Cervical Myelopathy?: An Individual Participant Data Meta-Analysis
Authors: Bak Alex Beomju , Moghaddamjou Ali , Alvi Mohammed Ali , Harrop James S. , Arnold Paul M. , Fehlings Michael G.
Published: March 2024

INTRODUCTION:

Contradictions exist about impact of anterior vs. posterior surgical approach on outcomes of degenerative cervical myelopathy (DCM).

METHODS:

Individual patient data of subjects who underwent surgery for DCM was identified from a pooled dataset of the AO Spine CSM-North America, CSM-International, and CSM-Protect clinical studies. Primary outcomes were changes in short form 36 Physical Component Summary score (SF36-PCS) and mJOA score at 12 months. Secondary outcomes were change in total Neck Disability Index (NDI) score and SF36 Mental Component Summary score (SF36-MCS). Two comparison cohorts were created: i) anterior surgery and ii) posterior surgery. One-stage mixed-effects meta-analysis with study and treatment exposure as random effects was performed and reported with mean differences and 95% confidence intervals. A subgroup analysis planned a priori in mild DCM patients (mJOA 15-17) was performed.

RESULTS:

A total of 979 patients met eligibility criteria. Patients who had anterior decompressive surgery experienced greater improvements at 1yr of follow-up than those who underwent posterior decompressive surgery in SF36-PCS score (adjusted MD 1.57 [95% CI 0.11 to 3.03], p = 0.0348) and NDI score (adjusted MD 3.32 [95% CI 0.58 to 6.05], p = 0.0172). A greater proportion of patients that underwent anterior surgery achieved clinically important recovery of their NDI (OR 1.49 [95% CI 1.15 to 1.93], p = 0.002; aOR 1.46 [95% CI 1.08 to 1.96], p = 0.013) and SF36-PCS scores at 1yr (OR 1.45 [95% CI 1.12 to 1.88], p = 0.004, aOR 1.34 [95% CI 1.00 to 1.80], p = 0.052). In patients with mild DCM (n = 186), patients who underwent anterior decompressive surgery experienced greater improvements in SF36-PCS score, mJOA score, and Neck Disability Index score than posterior surgical patients.

CONCLUSIONS:

Anterior surgical decompression for DCM is associated with greater improvements in 1yr patient-reported outcomes than posterior surgical decompression.
371 The Impact of Thoracolumbar Inflection Point on Outcomes and Complications in Adult Spinal Deformity
Authors: Mir Jamshaid M. , Passias Peter G. , Lewis Stephen , Tretiakov Peter S. , Dave Pooja , Lafage Renaud , Smith Justin S. , Line Breton G. , Diebo Bassel G. , Daniels Alan H. , Gum Jeffrey Lynn , Protopsalt Themistocles
Published: March 2024

INTRODUCTION:

The importance of alignment on postoperative outcomes and mechanical complications has been well established. However, the impact of alignment parameters relative to thoracolumbar inflection point remains unclear.

METHODS:

ASD patients with 2-year data, fused in the lower-thoracic (T7-T12) to sacrum were included. Thoracolumbar inflection-point(IP), IP differences from UIV, LLA, and theoretical-IP based on Roussouly morphology were assessed. Cases were stratified based on IP changes from baseline (BL) into Caudal(L), Same(S), or Cranial(H). Analysis controlled for invasiveness, baseline deformity, frailty, and PJK prophylaxis.

RESULTS:

650 patients met inclusion. PJF or PJK with reoperation was associated with a more caudal BL-IP (L2 inferior end plate (EP) vs L1-body, p < .001). In adjusted analysis, a more caudal BL IP had 25% higher odds of developing PJF by 2Y (OR:1.26, p=0.003). Postoperative normalization to theoretical Roussouly IP was associated with decreased rates of rod breakage (p = .049), but had higher rates of PJF (p = .044). Stratifying groups based on IP change from BL, rates of PJK and PJF by 2Y were higher in H (p < .003), with no difference in meeting Roussouly target IP. There was 4.4x lower odds of developing PJF in L and 2.0x in S compared to H (p < .05). Increased distance of UIV to IP was associated with mechanical-complications (MC) (p < .05). Decreased distance between LLA-IP at BL was associated with MC (p = .04).

CONCLUSIONS:

Despite lower frailty and baseline deformity in the cohort with a more cranially adjusted postoperative inflection point, there were higher rates of PJK and PJF. Increased distance between lumbar lordosis apex and inflection point was associated with higher rates of PJK, PJF, and thoracic decompensation. Correspondingly, a greater distance between the upper instrumented vertebra and inflection point was predictive of development of regional decompensation. The target inflection point can be an important parameter to minimize complications associated with ASD surgery.
375 Cervical Arthroplasty in the Treatment of Myelopathy: Clinical Predictors, Utilization, and Outcomes in a Large Administrative Database
Authors: Norval de Leeuw Charles , Yoo Jung U. , Orina Josiah N.
Published: March 2024

INTRODUCTION:

Cervical arthroplasty is a treatment for cervical radiculopathy; however, it may also be safe and effective in patients with mild myelopathy.

METHODS:

Retrospective data spanning 2016-2020 from the PearlDiver Patient Claims Database was used to select patients. Age, gender, osteoporosis, obesity, smoking, diabetes, Charlson Comorbidity Index (CCI), and 1- or 2-level surgery, re-operation rates, 90-day readmission, medical complications, and morphine milligram equivalents (MME) before/after surgery were collected. Univariate & multivariate analyses were performed to identify differences. Reoperation rates were compared using propensity-matched analysis.

RESULTS:

We identified n = 2,391 (4.5%) CDA and n = 50,845 ACDF procedures for cervical myelopathy. Predictors favoring CDA included female sex, younger age, lower CCI score, lower incidence of obesity, osteoporosis, diabetes, or smoking (p ≤ 0.001); remaining significant after multivariate analysis except sex (p = 0.06). Single-level surgery was more predictive for undergoing CDA. CDA patients had lower 90-day readmissions, complications, and lower opioid utilization. The overall reoperation rate was 5%. Predictors of reoperation included: male sex, younger age, greater CCI, obesity, osteoporosis, diabetes, smoking, and 2-level surgery, remaining significant after multivariable logistic regression except for diabetes (p = 0.23) and CCI (p = 0.05). The robustness of these factors were evaluated by matching patients (n = 2,391) with no difference in re-operation rates identified (p = 0.47).

CONCLUSIONS:

CDA patients are generally healthier (lower incidence of obesity, smoking, diabetes, CCI) and represents 4.5% of procedures for 1- or 2-level cervical myelopathy. Readmission rates, medical complications, and opiate use was lower with patients undergoing CDA, despite an overall similar reoperation rate. This study is limited by its retrospective nature and the lack of granular outcomes measurements. However, the data suggests that CDA is a viable option for cervical myelopathy.
387 Adaptive Priming Meets Innate Killing: TCR-Activated CD8+ T Cells Can Kill Tumor Cells in an MHC-Independent Manner via NKG2D
Authors: Fecci Peter Edward , Lerner Emily
Published: March 2024

INTRODUCTION:

The accepted paradigm for antitumor immunity relies upon tumor cell kill by CD8+ T cells recognizing cognate antigens presented in the context of target cell major histocompatibility complex class I (MHC-I) molecules.

METHODS:

We sought to better evaluate the role of MHC-I expression within the tumor microenvironment.

RESULTS:

T cell-activating immunotherapies, surprisingly, remained effective against glioma and melanoma lines engineered to lack MHC-I expression. Such efficacy proved independent of NK cells and, instead, relies consistently upon CD8+ T cell-mediated cytotoxicity, despite the absence of MHC-I on tumor targets. This cytotoxicity is both antigen- and MHC-agnostic and, instead, is mediated by T cell NKG2D engagement of NKG2D ligands on tumor cells, which are upregulated on MHC-loss variants. Necessarily, tumor cell kill in these instances is antigen-independent, although prior T cell receptor activation is required and can be furnished by myeloid cells or even neighboring MHC-replete tumors cells. In this manner, adaptive priming can beget innate killing. These mechanisms are active in vivo in mice, as well as in vitro in human tumor systems, and are obviated by NKG2D knockout or blockade. Tumor cell killing following T cell NKG2D engagement is Fas-independent and appears to involve granzyme.

CONCLUSIONS:

Such findings challenge the traditional model of T cell-mediated tumor immunity and likewise identify the NKG2D/NKG2DL axis as a novel therapeutic target for enhancing T cell killing of MHC loss variants.
393 Cerebral Oximetry Using the USIC Protocol Is a Reliable Tool for Indicating Selective Intraluminal Shunting During Carotid Endarterectomy
Authors: Hejcl Ales , Jiránková Katerina , Hrach Karel , Sames Martin
Published: March 2024

INTRODUCTION:

Indication to selective shunting during carotid endarterectomy (CEA) is based on monitoring during the procedure. Cerebral oximetry (CO) using near-infrared spectroscopy (NIRS) is one of the monitoring tools but no clear cut off value for an intraluminal shunt insertion has been established.

METHODS:

125 patients underwent CEA under LA and were monitored clinically through the whole procedure. The patients also underwent bilateral NIRS monitoring during the surgery. During the monitoring period, we first clamped the external carotid artery (ECA), and after a 1 minute delay followed by clipping the internal carotid artery (ICA). The decrease in the cerebral oximetry values was analyzed separately after selective ICA clipping (ÚstÍ Selective Internal carotid artery Clamping “USIC” protocol). The decision to use a shunt was based solely on clinical symptomatology but the NIRS data were recorded and analyzed. All patients underwent DWI before and after CEA.

RESULTS:

One hundred and six patients (85%) underwent CEA without clinical deterioration while 19 patients (15%) clinically deteriorated during surgery. The mean drop in the cerebral oximetry after selective ICA clamping in clinically stable patients was 6% while in patients with clinical deterioration the NIRS decreased by 15% (p < 0.05). When we set the cut-off value for selective shunting as a 10% decrease of the ipsilateral cerebral oximetry after selective ICA clamping, the sensitivity of the technique was 100% and the specificity 83%.

CONCLUSIONS:

Our study showed that a 10% decrease in the ipsilateral brain tissue oximetry after selective cross-clamping the ICA provides a reliable cut-off for selective shunting during CEA. More, bilateral NIRS monitoring allows differentiation between systemic or local events leading to brain hypoxia.
401 Applying Machine Learning for Risk Stratification and Acute Clinical Outcome Prediction Amongst Aneurysmal Subarachnoid Hemorrhage Patients
Authors: Buchlak Quinlan , Leveque Jean-Christophe A. , Krause Katie L. , Farrokhi Farrokh
Published: March 2024

INTRODUCTION:

Subarachnoid hemorrhage (SAH) is a common stroke subtype and is often caused by aneurysmal rupture. Accurately predicting aneurysmal SAH (aSAH) clinical outcomes may facilitate timely and effective treatment.

METHODS:

A dataset encompassing 12,070 aSAH Australian patients was analysed using multivariate logistic regression and machine learning techniques. Models were designed to predict the need for a surgical procedure, intensive care unit (ICU) admission, the need for continuous ventilation, prolonged length of stay (LOS), mortality, and discharge status.

RESULTS:

Surgical intervention was positively associated with younger age and female gender and negatively associated with indigenous Australian status. ICU admission was positively associated with age, female gender, surgery and indigenous status. The need for continuous ventilation was associated with age and ICU admission and negatively associated with female gender and surgery. Prolonged LOS was associated with older age, undergoing surgery and requiring ICU admission. Mortality was negatively associated with younger age, female gender and receiving surgical treatment. The Monash SAH Scores were developed, consisting of four scales that may be used to efficiently facilitate risk stratification and decision making in clinical practice. Machine learning models were capable of accurately predicting mortality with strong performance.

CONCLUSIONS:

This nation-wide study identified risk factors associated with acute clinical outcomes amongst aSAH patients. A simple scoring system was developed that may be readily applied to clinical practice to facilitate aSAH patient risk stratification and treatment planning.
403 Malignant Cerebral Venous Infarction: Decompressive Craniectomy Versus Medical Treatment
Authors: Ahmadi Sina , Baharvahdat Humain , Ganjeifar Babak , Etemadrezaie Hamid , Zabihyan Samira , Mowla Ashkan
Published: March 2024

INTRODUCTION:

Cerebral venous thrombosis (CVT) is a common stroke in young adults and is associated with 8% mortality. High intracranial pressure (ICP) and brain herniation are these patients' most common causes of death.

METHODS:

In this retrospective study, Patients with the following inclusion criteria have entered the study: 1) CVT proven by contrast-enhanced magnetic resonance venogram and/or computed tomography venogram, 2) malignant CVT (impending brain herniation according to imaging and clinical finding), and 3) age between 16 and 80 years. Patients with deep venous system thrombosis, Glasgow Coma Scale (GCS) score of 3, and bilateral nonreactive mid-position pupils or mydriasis on admission were excluded. Patients were classified into 2 groups: surgical group (DC group) including patients who received medical treatment and DC and medical group (MG) including patients who received only medical treatment. Outcomes and complications were assessed and compared between the 2 groups.

RESULTS:

Of 357 patients with CVT hospitalized in our center, 48 patients entered the study. 23 patients were managed medically, and 25 patients were managed surgically. There was no significant difference between the groups concerning age, sex, presenting symptoms, transient and permanent risk factors of CVT, GCS score on admission, and pupils’ reactivity on admission. All patients in the MG died during hospitalization in comparison with 8 patients in the DC group (100% vs. 32%, P < 0.001). A favorable outcome (modified Rankin scale score 0e2) was achieved in 52% of the DC group and 0% of the MG group (P < 0.001).

CONCLUSIONS:

Our study confirmed that in contrast with DC, medical treatment could not prevent transtentorial herniation. DC is not only lifesaving for patients with CVT with impending brain herniation but also results in favorable outcomes in most patients.
407 Results of Biphasic Calcium Phosphate Bone Graft With Submicron-Sized Needle-Shaped Surface Topography as Standalone Alternative to Autograft Are Favorable in a Prospective, Multi-center, Randomized, Intra-patient Controlled Trial
Authors: Fanous Andrew , Butrico Casey , Delawi Diyar , Hoebink Eric , Kempen Diederik , Van Susante Job , Kruyt Moyo
Published: March 2024

INTRODUCTION:

Pseudoarthrosis after spinal fusion is an important complication leading to revision spine surgeries. Iliac Crest Bone Graft is considered the gold standard, but with limited availability and associated co-morbidities, spine surgeons often utilize alternative bone grafts.

METHODS:

Adult patients indicated for instrumented PLF of one to six levels from T10-S2 were enrolled at five participating centers. After preparation of the bone bed, one side was grafted with 10 cc of autograft per level containing a minimum of 50% iliac crest bone. The other side was grafted with 10 cc of BCP < µm granules standalone. In total, 71 levels were treated. Prospective follow-up included a fine-cut (<1 mm) Computerized Tomography (CT) at one year. Fusion was systematically scored as fused or not fused per level per side by two spine surgeons blinded for the procedure.

RESULTS:

The first fifty patients enrolled are included in this analysis. Average age was 57 years old, with 60% female and 40% male. The diagnoses included deformity (56%), structural instability (28%), and instability from decompression (20%). The fusion rate determined by fine-cut CT for BCP < μm was 76.1% (54/71 levels), which compared favorably to the autograft fusion rate of 43.7% (31/71 levels). Fusion of the BCP < μm side was not contingent upon fusion of the autograft side, as 36.6% (26/71) of levels fused on the BCP < μm side but did not fuse on the autograft side. Binomial modeling revealed that the odds of fusion of BCP < μm was 2.54 times higher than that of autograft.

CONCLUSIONS:

These data, aiming to determine non-inferiority of standalone BCP < μm as compared to autograft for PLF, are promising. Ongoing studies with additional patients are forthcoming.
409 Evaluation of a Novel Vancomycin-Infused, Biomimetic Bone Graft in a Rat model of Spinal Implant-Associated Infection
Authors: Rajkovic Christian , Tracz Jovanna , DeMordaunt Trevor , Davidar Daniel , Perdomo-Pantoja Alexander , Judy Brendan F. , Cottrill Ethan , Hernandez Vaughn , Lin Jessica , Lazzari Julianna , Dikeman Dustin , Archer Nathan , Witham Timothy F.
Published: March 2024

INTRODUCTION:

Postoperative infection is a complication of spinal fusion surgery resulting in increased patient morbidity. Strategies including intraoperative application of powdered vancomycin have been proposed to reduce the incidence of infection, however such antimicrobial effects are short-lived.

METHODS:

Instrumentation of the L4-L5 vertebrae was performed mimicking pedicle screw and rod fixation in 30 rats. Titanium inoculated with PBS or 1x105 CFU bioluminescent MRSA and biomimetic bone grafts infused with varying concentrations of vancomycin were inserted before closure. Infection was quantified during the six-week postoperative period using IVIS bioluminescent imaging. Arthrodesis was evaluated using micro-CT. Histological analysis was utilized to evaluate fusion and leukocyte infiltration.

RESULTS:

Infected animals receiving a bone graft infused with high-dose vancomycin (0.89 mg/g) exhibited significantly lower bioluminescent signal over the six-week postoperative infection period (p = 0.032) than control animals inoculated with MRSA and implanted with bone grafts lacking vancomycin. Both high and low-dose (0.18 mg/g) vancomycin-infused grafts resulted in a statistically significant reduction in average bioluminescence when compared to control animals (p = 0.018 and p = 0.027, respectively), independent of time. MicroCT analysis of animals from each group revealed pseudoarthrosis only in the control group, suggesting a correlation between infection and pseudoarthrosis. Histology revealed the formation of fusion masses in all animals receiving vancomycin infused-bone grafts regardless of MRSA inoculation, with clearance of infection indicated by lack of abscess formation. MRSA-inoculated control animals receiving no vancomycin within the bone graft demonstrated significant abscess formation and lack of fusion mass.

CONCLUSIONS:

The novel vancomycin-infused, biomimetic bone graft effectively mitigated implant-associated infection while promoting fusion in a rat model of instrumented lumbar fusion.
412 Incisional Negative Pressure Wound Therapy Following Posterior Instrumented Spinal Fusion: A Single Surgeon’s Experience and Cost-Benefit Analysis
Authors: Kramer Dallas E. , Bharthi Rosh , Myers Daniel , Chang Patrick , Dabecco Rocco M. , Xu Chen , Kwong-Tak Yu Alexander
Published: March 2024

INTRODUCTION:

Surgical site infections (SSIs) following spine surgery are associated with significant morbidity and resource utilization.

METHODS:

We retrospectively reviewed all patients who received posterior instrumented spinal fusion by the senior author between July 2017 and December 2019 at a Level I trauma center. Statistical analysis was performed using Chi-square and Student’s t-tests.

RESULTS:

A total of 85 patients with standard surgical dressings and 144 patients with iNPWT were included for analysis. Patients in the iNPWT group were significantly older (61.8 vs. 58.5 years, p = 0.042) and more likely to be diabetic (36.8% vs. 23.5%, p = 0.037). Surgeries in the iNPWT group were associated with significantly greater blood loss (1298 mL vs. 998 mL, p = 0.036) and involved more instrumented levels (6.6 vs. 4.9, p < 0.0001). Prophylactic iNPWT use was associated with significantly lower rates of wound dehiscence (21.5% vs. 34.1%, p = 0.036) and SSI requiring operative treatment (8.3% vs. 21.2%, p = 0.005). The incidence of wound dehiscence requiring operative wound revision was lower with iNPWT (14.6% vs. 24.7%, p = 0.056), though it did not reach statistical significance. Number needed to treat (NNT) with iNPWT to prevent one SSI was 7.79. The cost of preventing one operative SSI was $5,096. Cost-benefit analysis demonstrated a potential mean savings of $26,149 per operative SSI and $326,862 per 100 patients undergoing posterior instrumented spinal fusion with iNPWT.

CONCLUSIONS:

Prophylactic iNPWT use significantly reduced rates of wound dehiscence, SSI requiring operative treatment, and affords a potential SSI-related cost savings of $326,862 per 100 patients treated.
420 Decrease in Post-Coiling Aneurysm Recanalization With Regular Aspirin Use
Authors: Spellicy Samantha , Kraljic Steven , Abdelgadir Jihad , Zomorodi Ali R. , Torner James , Hasan David M.
Published: March 2024

INTRODUCTION:

Endovascular coiling has remained an efficacious mechanism for aneurysm treatment. While continued biomechanical advancements in coil design have led to improved aneurysm embolization rates (1), aneurysm recanalization is estimated to remain between 21-33% (2, 3, 4). Post-occlusion, cerebral aneurysm sac growth has been identified as one of the driving components of aneurysm recurrence (2, 5). Recently, antiplatelet agents such as aspirin (ASA) have been shown to be significantly associated with decreased aneurysm growth and rupture (6, 7, 8).

METHODS:

All aneurysms treated by a single surgeon over 10 years (n = 2236) were screened for adherence to inclusion criteria. The primary endpoint was follow-up more than 12 months from the original intervention. Of 525 treated with coils only, 109 patients reported regular ASA use (defined as = 3x/ week, irrespective of dose). No significant demographic differences were identified between patients with regular ASA use and those without. While there were no significant differences in aneurysm size, location, or history of rupture, there was an increased presence of daughter sacs in patients without regular ASA. Rates of aneurysm recanalization, defined as a change of Raymond-Roy occlusion classification =1, were compared between ASA-treated and non-ASA-treated groups.

RESULTS:

Of the 109 coiled aneurysms with concomitant regular ASA use, only 9.2% underwent recanalization compared to 23.6% in patients without regular ASA use (P = 0.001, OR = 0.33, 95% CI = 0.15–0.66). Furthermore, when specifically considering cases of recanalization that only demonstrated sac growth, 5.5% occurred with regular ASA use compared to 18% without (P = 0.001, OR = 0.26, 95% CI = 0.09–0.63).

CONCLUSIONS:

ASA use significantly decreased the odds of post-coiling aneurysm sac growth and recanalization 12 months post-original intervention when compared to those without regular ASA use.
425 Getting Everyone Up to Speed: A Single Institution Pilot of a Neurosurgery Sub-internship Bootcamp
Authors: Suarez Alexander , Jackson Joshua , Raghavan Alankrita , Venkatraman Vishal , Cook Steven , McDaniel Kate , Goodwin C. Rory
Published: March 2024

INTRODUCTION:

At many institutions, first and second year medical students gain exposure to neurosurgery primarily through shadowing and research projects. Opportunities to acquire clinical experience and technical skills before a neurosurgery sub-internship are often limited. Consequently, students starting sub-internships have wide variability of clinical knowledge and experience.

METHODS:

We implemented a one-day boot camp at our university. The morning session followed a didactic format covering 14 topics. The afternoon session utilized hands-on stations: navigation-based EVD simulation, burr hole drilling, pinning, spine laminectomy/instrumentation, and OR orientation. Participants completed a pre-test and post-test survey using a 9-point Likert scale (Strongly Disagree [1] to Strongly Agree [9]).

RESULTS:

Ten medical students participated in the pilot. All participants rated the boot camp positively (Average score of 9.9 ± 0.2 out of 10). Students identified key areas they felt least comfortable with via the pre-test: functional neurosurgery (2.6 ± 1.4), management of neurosurgical floor patients (3.0 ± 1.6), and examination of comatose patients (4.1 ± 2.3). At the end of the event, students expressed statistically significant increased comfort across 16 of the 17 metrics; maximal improvement was noted in brain tumor imaging interpretation (5.9 ± 1.1 vs. 2.9 ± 1.9, p < .001) and knowing what is expected of a sub-intern (7.0 ± 1.1 vs. 4.0 ± 1.6, p < .001).

CONCLUSIONS:

We successfully implemented a one-day boot camp for medical students about to start their sub-internships. Moving forward, we plan to expand the hands-on learning to other medical students in the region and provide the didactic sessions virtually to allow participation on a national scale. In doing so, we hope to increase sub-internship readiness and reduce barriers for all students interested in neurosurgery.
427 Optimization of Morbidity and Mortality Conference: Results of a Multi-center Pilot at Neurosurgical Training Programs
Authors: Santarelli Justin G. , Sayama Christina M. , Shah Kushal , Benzil Deborah L.
Published: March 2024

INTRODUCTION:

Neurosurgical morbidity and mortality (M&M) conference is essential to resident education and to quality control. Training programs use different methods for executing the conference, with variability in presentation format, case inclusion criteria, adjudication of findings, and follow-up strategy. Optimal format for this conference is debated.

METHODS:

Ten ACGME-accredited neurosurgical training programs participated in a 3-month pilot to optimize M&M conference. A standardized format was implemented, using a broadly inclusive strategy for case selection, with morbidities selected by residents. Each neurosurgical complication was defined, in group discussion, according to type of error: indication; technique; procedure; judgment; nature of disease. Follow-up intervention was drafted for each case. Surveys were distributed to trainees and attending neurosurgeons before and after the pilot to assess the new format compared to historical standard.

RESULTS:

A total of 302 surveys were returned from attending and resident physicians. Seventy-four % of respondents found the new format to be an improvement (“slightly improved” or “much improved”) and Eight-five % expressed preference for the new standardized format. Fifty-two % of resident respondents believed engagement at the conference was increased. Twenty-six % responded that significant process improvements resulted from the standardized format.

CONCLUSIONS:

This 3-month pilot to optimize neurosurgical M&M conference, undertaken at ten neurosurgery training programs, received favorable reviews by survey. Respondents endorsed high levels of faculty & resident engagement. Case categorization by error was favorably reviewed. Significant process improvements were only noted by a minority of respondents, however, perhaps related to the short duration of the pilot. Overall these results suggest that future amplification of a standardized M&M format across neurosurgical training programs could yield high satisfaction and enhanced resident engagement. Additional attention focused on process improvement will be critical.
428 Artificial Intelligence Training Versus In-person Expert Training in Teaching Simulated Tumor Resection Skills - A Cross-Over Randomized Controlled Trial
Authors: Yilmaz Recai , Fazlollahi Ali , Alsayegh Ahmad , Bakhaidar Mohamad , Del Maestro Rolando
Published: March 2024

INTRODUCTION:

Neurosurgical simulations equipped with artificial intelligence systems provide an objective quantitative assessment of surgical technical skills and tailored intelligent feedback. These systems allow for repeated practice of complex skills such as subpial brain tumor resection. However, more work is needed to assess the utility of intelligent systems in teaching tumor resection skills, compared to traditional human instruction.

METHODS:

Twenty-five trainees who are currently enrolled in four Canadian medical schools participated in two training sessions, during which they completed a simulated subpial tumor resection five times. Participants were randomly assigned to two feedback groups: (1) real-time intelligent instruction, and (2) in-person human instruction. They were then assigned to the other feedback group in the second (cross-over) session. A composite-score was given by the intelligent system to assess technical skills during each task.

RESULTS:

Trainees who received real-time intelligent instruction significantly improved their composite-score in the first and second training sessions (p = .017, p = .005, respectively). Trainees who received in-person human instruction in the first training session had no statistically significant changes in their composite-score from the first to the last task repetition (p = .119). The composite-score decreased significantly in the second training session with in-person human instruction (p = .004).

CONCLUSIONS:

Real-time intelligent instruction provides an effective way of teaching simulated brain tumor resection skills. Artificial intelligence systems may be a useful addition to current surgical training curricula, providing objective, and tailored assessment and teaching of surgical technical skills in risk-free realistically simulated patient cases. Educators can benefit from these systems to guide their supervision, while trainees can use them for self-guided skill acquisition. Further research may assess the generalizability of these findings to other surgical procedures.
439 Optimal Targets, Connectivity, and Tissue Integrity for Deep Brain Stimulation in Patients With Disorders of Consciousness
Authors: Warren Aaron , Raguz Marina , Chudy Darko , Rolston John
Published: March 2024

INTRODUCTION:

Disorders of consciousness (DOC) are characterized by alterations in arousal and/or awareness resulting from brain injuries. Deep brain stimulation (DBS) is an emerging treatment to restore arousal/awareness in DOC. However, little is known about optimal targets and whether outcomes depend on brain connectivity, tissue integrity, or reorganization potential.

METHODS:

Retrospective analysis of 38 patients with DOC who underwent unilateral DBS targeting thalamic centromedian nucleus (ages = 12-65 years). DOC resulted from anoxic (n = 26) or traumatic (n = 12) injuries. Patients were classified as ‘responders’ or ‘non-responders’ using Coma/Near Coma and Coma Recovery Scales. Volumes of tissue activated (VTAs) assessed DBS locations associated with favorable response. Correlations were also performed with age, regional brain volumes from pre-operative MRI, and structural connectivity calculated from patients’ VTAs using normative diffusion MRI.

RESULTS:

8/38 patients were responders and 24/38 non-responders; outcomes are pending in 6/38 patients due to <3 months follow-up. Favorable response was associated with younger age (median age = 19 years in responders, 42 years in non-responders) and greater volumes of whole-brain grey matter and subcortical regions including putamen, pallidum, caudate, and cerebellum. Responders also tended to have deeper and more medial implantations, with VTAs engaging parafascicular nucleus, reticular nucleus, and peri-midbrain red nucleus. In responders, VTA connectivity was higher with superior frontal gyrus, caudate, pallidum, and cerebellum, and lower with sensorimotor and occipital cortex.

CONCLUSIONS:

Efficacious DBS for DOC is linked to younger age, greater preservation of whole-brain grey-matter, greater volumes of and connectivity with select subcortical areas (pallidum, caudate, cerebellum), stronger connectivity with superior frontal gyrus, and stimulation of locations inferomedial to the centromedian nucleus. Findings may assist with optimizing patient selection, DBS targeting, and post-implantation programming.
445 Performance of the IMPACT and CRASH Prognostic Models for Traumatic Brain Injury in a Contemporary Multicenter Cohort: A TRACK-TBI Study
Authors: Yue John K. , Lee Young Min , Jain Sonia , Sun Xiaoying , van Essen Thomas , Elguindy Mahmoud , Pisica Dana , Belton Patrick , Deng Hansen , Satris Gabriela , Wong Justin , Kanter John , Ambati Vardhaan Sai , Puccio Ava , Mukherjee Pratik , Yuh Esther , Markowitz Amy , Valadka Alex B. , Tarapore Phiroz E. , Huang Michael C. , DiGiorgio Anthony Michael , Okonkwo David O. , Steyerberg Ewout W. , Lingsma Hester F. , Menon David K. , Ramsay Maas Andrew Ian , Manley Geoffrey T.
Published: March 2024

INTRODUCTION:

The International Mission on Prognosis and Analysis of Clinical Trials in Traumatic Brain Injury (IMPACT) and Corticosteroid Randomisation After Significant Head Injury (CRASH) prognostic models for mortality and functional outcome in traumatic brain injury (TBI) were developed using historical data from 1984-2004.

METHODS:

The prospective, 18-center Transforming Research and Clinical Knowledge in Traumatic Brain Injury study enrolled participants aged = 17-years who presented to Level 1 trauma center and received head computed tomography (CT) scan <24-hours of TBI. Data was extracted from participants meeting IMPACT (Glasgow Coma Scale (GCS) 3-12; completed 6-month Glasgow Outcome Scale-Extended (GOSE); N = 441) and CRASH criteria (GCS 3-14; completed 2-week and 6-month GOSE; N = 831). Original model coefficients were applied, and performances were assessed using discrimination (area under the receiver-operating characteristic curve (AUC)) and calibration (intercept; slope; [95% confidence interval]).

RESULTS:

IMPACT and CRASH models discriminated mortality (AUC = 0.77-0.81, 0.90-0.91, respectively) and unfavorable outcome (0.77-0.81; 0.83, respectively). The IMPACT Lab model overestimated mortality (intercept = -0.79 [-1.05, -0.53]; slope = 1.37 [1.05-1.69]) and acceptably estimated unfavorable outcome (intercept = 0.07 [-0.14, 0.29]; slope = 1.19 [0.96-1.42]). The CRASH CT model overestimated mortality (intercept = -1.06 [-1.36, -0.75]; slope = 0.96 [0.79-1.14]) and unfavorable outcome (intercept = -0.60 [-0.78, -0.41]; slope = 1.20 [1.03-1.37]). Calibration performance differences were observed across the 5 leading enrollment centers (IMPACT Lab model: intercept -1.66 to -0.35, slope 1.07-1.86; CRASH CT model: intercept -1.81 to -0.67, slope 0.67-1.56) and unfavorable outcome (IMPACT Lab model: intercept -0.57 to 0.34, slope 1.28-2.89; CRASH CT model: intercept -1.15 to -0.10, slope 1.02-1.44).

CONCLUSIONS:

IMPACT and CRASH models discriminated mortality and unfavorable outcome. Observed overestimations of mortality and unfavorable outcome underscore the need to develop prognostic models that incorporate contemporary changes in TBI casemix. Investigations to elucidate the relationships between increased survival, functional outcome, treatment intensity, and center-specific practices will be highly relevant.
449 The Efficiency of Non-surgical Therapies for the Treatment of Mortons Neuroma: A Systematic Review
Authors: Budihal Bhargavi R. , K Nischal , Singh Harminder
Published: March 2024

INTRODUCTION:

Morton’s neuroma or Intermetatarsal neuroma is a benign inflammation of the peripheral nerves in the feet causing sharp, burning metatarsalgia and significant morbidity while walking, running, etc. It occurs more in females because tight shoe styles put pressure on the nerve.

METHODS:

Keyword search of “Morton’s Neuroma”, “treatment”, “conservative” and “non-surgical” was conducted across MEDLINE, EMBASE, and Cochrane databases. Two cohort studies and seven Randomised Controlled Trials were included for review following PRISMA guidelines. These studies were reviewed for pain relief, functionality, and limitations of each procedure.

RESULTS:

Methylprednisolone injections were proved to reduce the Visual Analog Scale score with >50% cases showing no difficulty in functional daily activity at 9 months post-procedure. Short-term relief was achieved by alcohol and capsaicin injections independently. Modifications in the shoe insole indicated better functionality and analgesia compared to a flat insole but combined with steroids it showed better outcomes. Extracorporeal shockwave therapy provided relief for up to 3 months compared to radiofrequency ablation which provided relief for a longer period.

CONCLUSIONS:

Although these procedures show statistically significant changes, they are not without limitations. Well-designed randomized controlled trials looking into the avenues for radiofrequency ablation and shockwave therapies as opposed to surgical excision of neuromas are vital.