Three-column osteotomy in long constructs has lower rates of proximal junctional kyphosis and better restoration of lumbar lordosis than anterior column realignment.

PURPOSE: Three-column osteotomies (TCOs) and minimally invasive techniques such as anterior column realignment (ACR) are powerful tools used to restore lumbar lordosis and sagittal alignment. We aimed to appraise the differences in construct and global spinal stability between TCOs and ACRs in long constructs. METHODS: We identified consecutive patients who underwent a long construct lumbar or thoracolumbar fusion between January 2016 and November 2021. "Long construct" was any construct where the uppermost instrumented vertebra (UIV) was L2 or higher and the lowermost instrumented vertebra (LIV) was in the sacrum or ileum. RESULTS: We identified 69 patients; 14 (20.3%) developed PJK throughout follow-up (mean 838 days). Female patients were less likely to suffer PJK (p = 0.009). TCO was more associated with open (versus minimally invasive) screw/rod placement, greater number of levels, higher UIV, greater rate of instrumentation to the ilium, and posterior (versus anterior) L5-S1 interbody placement versus the ACR cohort (p < 0.001, p < 0.001, p < 0.001, p < 0.001, p = 0.005, respectively). Patients who developed PJK were more likely to have undergone ACR (12 (32.4%) versus 2 (6.3%, p = 0.007)). The TCO cohort had better improvement of lumbar lordosis despite similar preoperative measurements (ACR: 16.8 ± 3.78°, TCO: 23.0 ± 5.02°, p = 0.046). Pelvic incidence-lumbar lordosis mismatch had greater improvement after TCO (ACR: 14.8 ± 4.02°, TCO: 21.5 ± 5.10°, p = 0.042). By multivariate analysis, ACR increased odds of PJK by 6.1-times (95% confidence interval: 1.20-31.2, p = 0.29). CONCLUSION: In patients with long constructs who undergo ACR or TCO, we experienced a 20% rate of PJK. TCO decreased PJK 6.1-times compared to ACR. TCO demonstrated greater improvement of some spinopelvic parameters.

Patients' perceptions on outcomes after mechanical thrombectomy in acute ischemic stroke.

BACKGROUND: The modified Rankin Scale (mRS) is a clinician-reported scale that measures the degree of disability in patients who suffered a stroke. Patients' perception of a meaningful recovery from severe stroke, expected value of a stroke intervention, and the effect of disparities are largely unknown. METHODS: We conducted a survey of patients, their family members, and accompanying visitors to understand their personal preferences and expectations for acute strokes potentially eligible for acute endovascular intervention using a hypothetical scenario of a severe stroke in a standardized questionnaire. RESULTS: Of 164 survey respondents, 65 (39.6%) were the patient involved, 93 (56.7%) were a family member, and six (3.7%) were accompanied visitors (friends, other). Minimally acceptable disability after a stroke intervention was considered as mRS 2 by 42 respondents (25.6%), as mRS 3 by 79 (48.2%), and as mRS 4 by 43 (26.2%) respondents. Race was associated with different views on this question (p < 0.001; Hispanic and Black patients being more likely to accept disability than Caucasian and Asian patients), while sex (p = 0.333) and age (p = 0.560) were not. Sixty-three respondents (38.4%) viewed minimally acceptable probability of improvement with an intervention as over 50%, 57 (34.8%) as 10-50%, and 44 (26.8%) as less than 10%. CONCLUSIONS: A wide range of acceptable outcomes were reported regardless of gender or age. However, race was associated with different acceptable outcome. This is an important finding to demonstrate because of the persistent racial and ethnic disparities in the utilization of endovascular therapy for acute stroke in the United States.

C1-C2 intraarticular distraction with anterior cervical cages for basilar invagination realignment: Operative technique nuances and review of literature.

Neurosurgical management of basilar invagination (BI) has traditionally been aimed at direct cervicomedullary decompression through transoral dens resection or suboccipital decompression with supplemental instrumented fixation. Dr. Goel introduced chronic atlantoaxial dislocation (AAD) as the etiology in most cases of BI and described a technique for distracting the C1-C2 joint with interfacet spacers to achieve reduction and anatomic realignment. We present our modification to Goel's surgical technique, in which we utilize anterior cervical discectomy (ACD) cages as C1-C2 interfacet implants. A young adult male presented to our institution with BI, cervicomedullary compression, occipitalization of C1, and Chiari 1 malformation. There was AAD of C1 over the C2 lateral masses. This reduced some with preoperative traction. He underwent successful C1-C2 interfacet joint reduction and arthrodesis with anterior cervical discectomy (ACD) cages and concomittant occiput to C2 instrumented fusion. BI can be effectively treated through reduction of AAD and by utilizing ACD cages as interfacet spacers.

A meta-analysis and systematic review of endovascular thrombectomy versus medical management for acute basilar artery occlusion.

OBJECTIVE: Acute basilar artery occlusion (BAO) is a devastating neurologic event. As endovascular thrombectomy (EVT) became more prevalent for anterior circulation strokes, investigations were conducted in the posterior circulation. Its success in improving outcomes compared to standard medical therapy (SMT) after BAO has been debated. METHODS: We conducted a systematic review and meta-analysis of all randomized controlled trials (RCTs) and observational cohort studies evaluating EVT compared to SMT in acute BAO. We queried PubMed, Embase, and Cochrane for studies. Primary outcome was good functional outcome at 90 days (modified Rankin scale (mRS) ≤ 3). We analyzed studies for risk of bias (ROB) and calculated pooled risk ratios (RRs), odds ratios (ORs), and mean differences (MDs) with 95% confidence intervals (95%CI) using the random effects model for our primary outcome and secondary positive outcomes and harms. RESULTS: We identified four RCTs (991 patients randomized) and three cohort studies (1030 patients treated in-trial) that fit inclusion criteria. Three RCTs had low ROB, one had serious ROB. One cohort study had high ROB, one had moderate ROB, and one had low ROB. EVT was statistically significantly more associated with good functional outcome than SMT in RCTs (RR=1.54, 95%CI=1.16-2.04, p = 0.003) and trended towards significance in cohort studies (RR=2.64, 95%CI=0.87-8.00, p = 0.09). Mean mRS at 90 days was lower in EVT patients in RCTs (MD=-0.65, 95%CI=-1.07--0.22, p = 0.003) though not cohort studies (MD =-0.84, 95%CI=-2.48-0.79, p = 0.31). Symptomatic intracerebral hemorrhage (sICH) was statistically significantly associated with EVT in RCTs (OR=6.36, 95%CI=2.24-18.07, p < 0.001) and statistically non-significantly in cohort studies (OR=4.51, 95CI=1.00-20.33, p = 0.05). Mortality at 90 days was statistically lower with EVT than with SMT in both RCTs (OR=0.76, 95%CI=0.65-0.88, p < 0.001) cohort studies (OR=0.36, 95%CI=0.26-0.50, p < 0.001) CONCLUSION: EVT is associated with greater rates of good functional outcomes and lower rates of death and disability despite higher rates of periprocedural sICH.

Nasofrontal meningiomas: retrospective series and review of literature.

INTRODUCTION: Lesions affecting the anterior skull base and involving the paranasal sinuses (PNS), nasal cavity (NC), and orbit are infrequent and include predominantly a wide variety of sinonasal malignancies. Less than 3% of intracranial meningiomas extend extracranially and involve PNS and NC. Given their relatively low incidence, little is known about the treatment outcome of this subset of meningiomas. METHODS: Systematic literature and retrospective review of own institutional series of midline anterior skull base meningiomas with significant PNS and NC involvement were performed. RESULTS: Overall, 21 patients-16 in the literature review group and 5 of our institutional series-were included. Eleven (52.4%) patients had had a prior surgery for midline anterior skull base meningioma. Of patients having reported WHO grade, two were WHO II. Gross total resection was achieved in 16 (76.2%) of patients, utilizing solely transcranial approach in 15 patients, combined endoscopic and transcranial in five patients and purely endoscopic in one patient. Postoperative radiotherapy was administered in three (14.3%) patients, all after total resection via transcranial route, without a history of prior treatment. A postoperative cerebrospinal fluid leak was reported in four (10%) patients, requiring surgical repair in two. There were no reports of postoperative meningitis. No neurological complications were observed except of a reported worsening of vision in one patient. CONCLUSION: Midline anterior skull base meningiomas infrequently extend significantly into the PNS and NC. Despite their significant involvement, along with concomitant involvement of orbit, gross total resection is possible in the majority of cases with low morbidity using either purely transcranial or combined endoscopic/transcranial approach.

Percutaneous Vertebroplasty and Upper Instrumented Vertebra Cement Augmentation Reducing Early Proximal Junctional Kyphosis and Failure Rate in Adult Spinal Deformity: Case Series and Literature Review.

BACKGROUND AND OBJECTIVES: One of the risks involved after long-segment fusions includes proximal junctional kyphosis (PJK) and proximal junctional failure (PJF). There are reported modalities to help prevent this, including 2-level prophylactic vertebroplasty. In this study, our goal was to report the largest series of prophylactic cement augmentation with upper instrumented vertebra (UIV) + 1 vertebroplasty and a literature review. METHODS: We retrospectively reviewed our long-segment fusions for adult spinal deformity from 2018 to 2022. The primary outcome measures included the incidence of PJK and PJF. Secondary outcomes included preoperative and postoperative Oswestry Disability Index, visual analog scale back and leg scores, surgical site infection, and plastic surgery closure assistance. In addition, we performed a literature review searching PubMed with a combination of the following words: "cement augmentation," "UIV + 1 vertebroplasty," "adjacent segment disease," and "prophylactic vertebroplasty." We found a total of 8 articles including 4 retrospective reviews, 2 prospective reviews, and 2 systematic reviews. The largest cohort of these articles included 39 patients with a PJK/PJF incidence of 28%/5%. RESULTS: Overall, we found 72 long-segment thoracolumbar fusion cases with prophylactic UIV cement augmentation with UIV + 1 vertebroplasty. The mean follow-up time was 17.25 months. Of these cases, 8 (11.1%) developed radiographic PJK and 3 (4.2%) required reoperation for PJF. Of the remaining 5 patients with radiographic PJK, 3 were clinically asymptomatic and treated conservatively and 2 had distal fractured rods that required only rod replacement. CONCLUSION: In this study, we report the largest series of patients with prophylactic percutaneous vertebroplasty and UIV cement augmentation with a low PJK and PJF incidence of 11.1% and 4.2%, respectively, compared with previously reported literature. Surgeons who regularly perform long-segment fusions for adult spinal deformity can consider this in their armamentarium when using methods to prevent adjacent segment disease because it is an effective modality in reducing early PJK and PJF that can often result in revision surgery.

Risk Factors for Adjacent Segment Disease in Short Segment Lumbar Interbody Fusion-A Case Series.

BACKGROUND: Adjacent segment disease (ASD) is a common problem after lumbar spinal fusions. Ways to reduce the rates of ASD are highly sought after to reduce the need for reoperation. OBJECTIVE: To find predisposing factors of ASD after lumbar interbody fusions, especially in mismatch of pelvic incidence and lumbar lordosis (PI-LL). METHODS: We conducted a retrospective cohort study of all patients undergoing lumbar interbody fusions of less than 4 levels from June 2015 to July 2020 with at least 1 year of follow-up and in those who had obtained postoperative standing X-rays. RESULTS: We found 243 patients who fit inclusion and exclusion criteria. Fourteen patients (5.8%) developed ASD, at a median of 24 months. Postoperative lumbar lordosis was significantly higher in the non-ASD cohort (median 46.4° ± 1.4° vs 36.9° ± 3.6°, P < .001), pelvic tilt was significantly lower in the non-ASD cohort (16.0° ± 0.66° vs 20.3° ± 2.4°, P = .002), PI-LL mismatch was significantly lower in the non-ASD cohort (5.28° ± 1.0° vs 17.1° ± 2.0°, P < .001), and age-appropriate PI-LL mismatch was less common in the non-ASD cohort (34 patients [14.8%] vs 13 [92.9%] of patients with high mismatch, P < .001). Using multivariate analysis, greater PI-LL mismatch was predictive of ASD (95% odds ratio CI = 1.393-2.458, P < .001) and age-appropriate PI-LL mismatch was predictive of ASD (95% odds ratio CI = 10.8-970.4, P < .001). CONCLUSION: Higher PI-LL mismatch, both age-independent and when adjusted for age, after lumbar interbody fusion was predictive for developing ASD. In lumbar degenerative disease, correction of spinopelvic parameters should be a main goal of surgical correction.

Factors associated with hardware failure after lateral thoracolumbar fusions - A ten year case series.

OBJECTIVE: Thoracolumbar lateral interbody fusions (tLLIF) are one tool in the spine surgeon's toolbox to indirectly decompress neuroforamina while also improving segmental lordosis in a biomechanically distinct manner from posterior fusions. When part of a concomitant posterior construct, hardware failure (HF), sometimes requiring revision surgery, can occur. We sought to study the relationship between tLLIF and HF. METHODS: We conducted a retrospective study on consecutive patents who underwent tLLIF at a single academic center between January 2012 and December 2021 by seven unique neurosurgeons. Patients were excluded if they had no posterior instrumentation within their construct or if they had less than six months of follow-up. Hardware failure was defined as screw breakage or rod fracture seen on postoperative imaging. RESULTS: 232 patients were identified; 6 (2.6 %) developed HF throughout a mean follow-up of 1182 days (range =748-1647 days). Adjacent segment disease was the most common pathology addressed (75 patients (32.3 %)). The amount of posterior instrumentation both in the surgery in question and in the total construct were significantly higher in the HF cohort (4.33 ± 1.52 levels, 5.83 ± 3.36 levels) versus the non-HF cohort (2.08 ± 0.296 levels, p = 0.014; 2.86 ± 0.316 levels, p = 0.003, respectively). The number of interbody devices added in the index surgery and in the entire construct were both significantly higher in the HF cohort (3.33 ± 0.666 interbody devices, 3.33 ± 0.666 devices) than in the non-HF cohort (1.88 ± 0.152 interbody devices, p = 0.002; 2.31 ± 0.158 devices, p = 0.036, respectively). Higher amounts of lateral levels of fusion approached significance for association with HF (HF: 2.67 ± 0.844 levels, no HF: 1.73 ± 1.26 levels, p = 0.076). On multivariate analysis, only the number of interbody devices added in the index surgery was predictive of HF (Odds ratio=2.3, 95 % confidence interval=1.25-4.23, p = 0.007). CONCLUSION: Greater levels of posterior fusion, and greater numbers of interbody devices in an index surgery and in a construct as a whole, were associated with higher rates of HF in our cohort of patients with tLLIF. Greater numbers of lateral segments fused in this population may also be related to HF.

Improved Outcomes with Concurrent Instrumentation and Fusion of the Sacroiliac Joint in Patients with Long Lumbosacral Constructs.

STUDY DESIGN: Retrospective Cohort Study. OBJECTIVE: Spinal fusion, specifically constructs connected to pelvic bones, has been consistently reported as a predisposing factor to sacroiliac joint (SIJ) pain. The aim of this study is to compare SIJ outcomes in patients with constructs to the pelvis following instrumentation vs instrumentation plus fusion of the SIJ. METHODS: Data of study subjects was extracted from a prospectively maintained database as well as retrospectively collected from records at a tertiary academic medical center in the United States between 2018 and 2020. RESULTS: A cohort of 103 patients was divided into 2 groups: 65 in Group 1 [S2AI screw without fusion device] and 38 in Group 2 [S2AI screw with fusion device]. None of the patients in Group 2 developed postoperative SIJ pain compared to 44.6% in Group 1. Sacroiliac joint fusion occurred in all Group 2 but none of Group 1 patients. The postoperative Visual Analogue Scale (VAS) for lower extremity (LE) pain (.8 vs .5; P = .03) and postoperative Oswestry Disability Index (ODI) (18.7 vs 14.2; P < .01) were significantly higher in Group 1. The rate of distal junctional break, failure, and/or kyphosis (DJBFK) and time to DJBFK were not significantly different between the two groups, and the rate of DJBFK did not change in the presence of multiple covariates. CONCLUSION: The SIJs carry the heavy load of long lumbosacral fusion constructs extending to the pelvis. Simultaneous SIJ instrumentation and fusion decreases the risk of disability, prevents the development of postoperative SIJ pain, and may also protect the S2AI screw from loosening and failure.

Endovascular Therapy vs Medical Management for Patients With Acute Stroke With Medium Vessel Occlusion in the Anterior Circulation.

Importance: Randomized clinical trials have shown the efficacy of endovascular therapy (EVT) for acute large vessel occlusion strokes. The benefit of EVT in acute stroke with distal, medium vessel occlusion (DMVO) remains unclear. Objective: To examine the efficacy and safety outcomes associated with EVT in patients with primary DMVO stroke when compared with a control cohort treated with medical management (MM) alone. Design, Setting, and Participants: This multicenter, retrospective cohort study pooled data from patients who had an acute stroke and a primary anterior circulation emergency DMVO, defined as any segment of the anterior cerebral artery (ACA) or distal middle cerebral artery, between January 1, 2015, and December 31, 2019. Those with a concomitant proximal occlusion were excluded. Outcomes were compared between the 2 treatment groups using propensity score methods. Data analysis was performed from March to June 2021. Exposures: Patients were divided into EVT and MM groups. Main Outcomes and Measures: Main efficacy outcomes included 3-month functional independence (modified Rankin Scale [mRS] scores, 0-2) and 3-month excellent outcome (mRS scores, 0-1). Safety outcomes included 3-month mortality and symptomatic intracranial hemorrhage. Results: A total of 286 patients with DMVO were evaluated, including 156 treated with EVT (mean [SD] age, 66.7 [13.7] years; 90 men [57.6%]; median National Institute of Health Stroke Scale [NIHSS] score, 13.5 [IQR, 8.5-18.5]; intravenous tissue plasminogen activator [IV tPA] use, 75 [49.7%]; ACA involvement, 49 [31.4%]) and 130 treated with medical management (mean [SD] age, 69.8 [14.9] years; 62 men [47.7%]; median NIHSS score, 7.0 [IQR, 4.0-14.0], IV tPA use, 58 [44.6%]; ACA involvement, 31 [24.0%]). There was no difference in the unadjusted rate of 3-month functional independence in the EVT vs MM groups (151 [51.7%] vs 124 [50.0%]; P = .78), excellent outcome (151 [38.4%] vs 123 [31.7%]; P = .25), or mortality (139 [18.7%] vs 106 [11.3%]; P = .15). The rate of symptomatic intracranial hemorrhage was similar in the EVT vs MM groups (weighted: 4.0% vs 3.1%; P = .90). In inverse probability of treatment weighting propensity analyses, there was no significant difference between groups for functional independence (adjusted odds ratio [aOR], 1.36; 95% CI, 0.84-2.19; P = .20) or mortality (aOR, 1.24; 95% CI, 0.63-2.43; P = .53), whereas the EVT group had higher odds of an excellent outcome (mRS scores, 0-1) at 3 months (aOR, 1.71; 95% CI, 1.02-2.87; P = .04). Conclusions and Relevance: The findings of this multicenter cohort study suggest that EVT may be considered for selected patients with ACA or distal middle cerebral artery strokes. Further larger randomized investigation regarding the risk-benefit ratio for DMVO treatment is indicated.

Neuromuscular Scoliosis: A Dual-Surgeon Approach.

OBJECTIVE: Neuromuscular Scoliosis (NMS) causes severe deformity and operative correction for these patients carries high complication rates. We present a retrospective study comparing a series of consecutive patients who underwent posterior fusion via a single-surgeon (SS) approach with a consecutive series of patients treated via a dual-surgeon (DS) approach. METHODS: Patients with NMS who underwent posterior fusion via a SS approach from 2019 to 2022 were analyzed and compared to a series of patients with NMS who underwent posterior fusion via a DS approach. RESULTS: In the SS group, the average estimated blood loss (EBL) was 675 mL, average length of stay (LOS) was 6.3 days, average operative time (OT) was 6.5 hours, average packed red blood cell transfusion was 1.5 units, with a complication rate of 30%. The DS group had an average EBL of 400 mL, a LOS of 4.8 days, an OT of 4.75 hours, an average packed red blood cell transfusion of 0.8 units, with a complication rate of 20%. The DS approach was significant for a lower EBL, OT (P < 0.001), and LOS (P < 0.03). CONCLUSIONS: This study suggests that for patients with NMS the DS approach decreases OT, EBL, complication rates, and LOS. This further supports that this approach may benefit outcomes in NMS patients.

Postoperative magnetic resonance imaging signal changes in middle cerebral peduncle after vestibular schwannoma surgery.

BACKGROUND AND PURPOSE: Preoperative compression of middle cerebellar peduncle (MCP) is often observed in vestibular schwannomas. Its re-expansion is expected after tumour resection, however, frequently its thickness remains unchanged or undergoes further atrophy. Similarly, increased MCP FLAIR signal is often observed and thought to be associated with intraoperative MCP injury. This study investigates the dynamics of MCP FLAIR signal changes over time and their implications in long-term MCP atrophy. MATERIALS AND METHODS: Retrospective analysis of patients operated between 2011 and 2019 was performed. Measurements of FLAIR signals and MCP thickness were performed preoperatively, postoperatively and at follow-up. RESULTS: 28 patients (15 females, mean age 51.94 years) were included. The mean follow-up was 23.98 months. The mean tumour size was 2.99 cm. The MCP FLAIR signal was elevated preoperatively in 10 (35.7%) patients and further increased postoperatively in 22 (78.6%), followed by its decrease at follow up (7 patients, 25%). An immediate postoperative re-expansion of middle cerebellar peduncle was observed in 24 (85.7%) patients. No association between tumour size and preoperative FLAIR was established, however tumour size was negatively associated with the MCP thickness. A significant negative association between a postoperative FLAIR and follow-up thickness (p < 0.001) was noted, even if controlling for tumour size and both tumour size and preoperative MCP thickness. CONCLUSION: In patients with vestibular schwannomas undergoing surgical resection, the middle cerebellar peduncle FLAIR signal seems to associated with long term thickness of MCP, regardless of its initial size, however does not seem to correlate with the clinical outcome.

Comparison of stent retriever thrombectomy using 3-dimensional patient-specific models of intracranial circulation with actual middle cerebral artery occlusion thrombectomy cases.

BACKGROUND AND PURPOSE: Stent retriever (SR) thrombectomy is commonly used for the treatment of emergent large vessel occlusion (ELVO) in acute ischemic stroke. Clot imaging parameters such as clot length, diameter, distance to the internal carotid artery terminus, and vessel angle where the SR is deployed may predict the likelihood of achieving first pass effect (FPE). Most of the proposed factors that seem to affect recanalization success have been studied individually, and conflicting data derived from clinical versus in vitro studies using 3-dimensional printed models of intracranial circulation currently exist. METHODS: Using patient-specific 3-dimensional phantoms of the cervical and intracranial circulation, we simulated middle cerebral arteries (MCA) M1 and M2 occlusions treated with SR thrombectomy using Solitaire (Medtronic) or Trevo (Styker). Our primary outcome was FPE, defined as Thrombolysis in Cerebral Infarction score of 2c-3 achieved after a single thrombectomy attempt. We also performed retrospective analysis of same clot imaging characteristics of consecutive cases of MCA occlusion and its association with FPE matching the 3-dimensional in vitro experiments. Analysis was conducted using IBM SPSS Statistics Version 25 (IBM Corp., Armonk, NY). Chi-square tests and bivariate logistic regressions were the main statistical tests used in analysis. A p-value of less than .05 was considered to indicate statistical significance. Ninety-five confidence intervals (95% CI) were generated. RESULTS: We compared 41 thrombectomy experiments performed using patient-specific 3-dimensional in vitro models with a retrospective cohort of 41 patients treated with SR thrombectomy. We found that in the in vitro cohort, higher MCA angulation was associated with a lower likelihood of FPE (odds ratio [OR] = 0.967, 95% CI = 0.944-0.991, p = .008). Meanwhile in the in vivo cohort, higher MCA angulation was associated with a higher likelihood of FPE (OR = 1.039, 95% CI = 1.003-1.077, p = .033). Neither clot length nor location of clot (M1 vs. M2) was associated with a difference in FPE rates in either cohort. DISCUSSION: Comparison of SR thrombectomy performed during actual MCA occlusion cases versus patient-specific 3-dimensional replicas revealed MCA angulation as an independent predictor of procedure success or failure. However, the opposite direction of effect was observed between the two studied environments, indicating potential limitations of studying SR thrombectomy using 3-dimensional models of LVO.

Prevention of Neurological Deficit With Intraoperative Neuromonitoring During Anterior Lumbar Interbody Fusion.

STUDY DESIGN: This was a retrospective cohort study. OBJECTIVE: While intraoperative neuromonitoring (IONM) has been increasingly used in spine surgery to have a real-time evaluation of the neurological injury, we aim here to assess its utility during anterior lumbar interbody fusion (ALIF) and its association with postoperative neurological deficit. SUMMARY OF BACKGROUND DATA: ALIF is a beneficial surgical approach for patients with degenerative disease of the lower lumbar spine who would benefit from increased lordosis and restoration of neuroforaminal height. One risk of ALIF is iatrogenic nerve root injury. IONM may be useful in preventing this injury. MATERIALS AND METHODS: We performed a retrospective cohort study of 111 consecutive patients who underwent ALIF at a tertiary care academic center by 6 spine surgeons. We aimed to describe the association between IONM, postoperative weakness, and factors that predispose our center to using IONM. RESULTS: The 111 patients had a median age of 62 years [interquartile range (IQR): 53-69 y]. Neuromonitoring was used in 67 patients (60.3%) and not used in 44 patients. Seven neuromonitoring patients had IONM changes during the surgery. Three of these patients' surgeries featured intraoperative adjustments to reduce iatrogenic neural injury. The IONM cohort underwent significantly more complex procedures [5 levels (IQR: 3-7) vs. 2 levels (IQR: 2-5), P=0.001]. There was no difference in rates of new or worsened postoperative weakness (IONM: 20.6%, non-IONM: 20.5%). CONCLUSIONS: We demonstrate evidence of the potential benefits of IONM for patients undergoing ALIF. Intraoperative changes in neuromonitoring signals resulted in surgical adjustments that likely prevented neurological deficits postoperatively. IONM was protective so that more complex surgeries did not have a higher rate of postoperative weakness.

Clot imaging characteristics predict first pass effect of aspiration-first approach to thrombectomy.

BACKGROUND: The value of clot imaging in patients with emergent large vessel occlusion (ELVO) treated with thrombectomy is unknown. METHODS: We performed retrospective analysis of clot imaging (clot density, perviousness, length, diameter, distance to the internal carotid artery (ICA) terminus and angle of interaction (AOI) between clot and the aspiration catheter) of consecutive cases of middle cerebral artery (MCA) occlusion and its association with first pass effect (FPE, TICI 2c-3 after a first attempt). RESULTS: Patients (n = 90 total) with FPE had shorter clot length (9.9 ± 4.5 mm vs. 11.7 ± 4.6 mm, P = 0.07), shorter distance from ICA terminus (11.0 ± 7.1 mm vs. 14.7 ± 9.8 mm, P = 0.048), higher perviousness (39.39 ± 29.5 vs 25.43 ± 17.6, P = 0.006) and larger AOI (153.6 ± 17.6 vs 140.3 ± 23.5, P = 0.004) compared to no-FPE patients. In multivariate analysis, distance from ICA terminus to clot ≤13.5 mm (odds ratio (OR) 11.05, 95% confidence interval (CI) 2.65-46.15, P = 0.001), clot length ≤9.9 mm (OR 7.34; 95% CI 1.8-29.96, P = 0.005), perviousness ≥ 19.9 (OR 2.54, 95% CI 0.84-7.6, P = 0.09) and AOI ≥ 137°^ (OR 6.8, 95% CI 1.55-29.8, P = 0.011) were independent predictors of FPE. The optimal cut off derived using Youden's index was 6.5. The area under the curve of a score predictive of FPE success was 0.816 (0.728-0.904, P < 0.001). In a validation cohort (n = 30), sensitivity, specificity, positive and negative predictive value of a score of 6-10 were 72.7%, 73.6%, 61.5% and 82.3%. CONCLUSIONS: Clot imaging predicts the likelihood of achieving FPE in patients with MCA ELVO treated with the aspiration-first approach.

Eloquence-based reperfusion scoring and its ability to predict post-thrombectomy disability and functional status.

BACKGROUND: Angiographic reperfusion after endovascular thrombectomy in acute ischemic stroke is commonly graded using volume-based reperfusion scores such as the modified thrombolysis in cerebral infarct score. The location of non-reperfused regions is not included in modified thrombolysis in cerebral infarct score. We studied the predictive ability of an eloquence-based reperfusion score. METHODS: Consecutive cases of endovascular thrombectomy for anterior circulation strokes performed between January 2018 and April 2020 were included. Digital subtraction angiograms were reviewed by two blinded neurointerventionalist operators. Incomplete reperfusion was further classified by lobar regions lacking reperfusion to create various cohorts. Outcomes were graded four to seven days post-procedure with the National Institute of Health Stroke Scale (NIHSS) and 90 days post-procedure with the modified Rankin Scale. RESULTS: One hundred patients were identified. Via multivariate analysis, we found that frontal lobe non-reperfusion (mean difference (MD) = -1.60, p = 0.002) and occipital lobe non-reperfusion (MD = -1.68, p = 0.001) were associated with worse mental status improvement while left-sided stroke (MD = 2.02, p < 0.001) featured better improvement post-thrombectomy. Occipital lobe non-reperfusion (MD = -0.734, p = 0.009) was associated with the worse improvement of visual fields. The non-reperfusion of the frontal lobe was associated with a 1.732-worse NIHSS hemibody strength score (95% confidence interval (95%CI) = -3.39 to -0.072, p = 0.041). Worse improvement in NIHSS scores was found to be associated with frontal lobe non-reperfusion (MD = -5.34, 95%CI = -9.52 to -1.18, p = 0.013) and occipital lobe non-reperfusion (MD = -6.35, 95%CI = -10.4 to -2.31, p = 0.002). Odds of achieving modified Rankin Scale of 0-2 at 90 days were decreased with frontal lobe non-reperfusion (odds ratio (OR) = 0.279, 95%CI = 0.090-0.869, p = 0.028) and left laterality (OR = 0.376, 95%CI = 0.153-0.922, p = 0.033). CONCLUSIONS: Eloquence-based reperfusion assessment is an important predictor for functional outcomes after thrombectomy.

Factors associated with in-stent stenosis after cerebral aneurysm embolization using a Pipeline embolization device.

BACKGROUND: Flow-diverting (FD) stents, with or without coiling, are a mainstay in endovascular treatment of intracranial aneurysms (IAs). One observed complication from flow diverter stent (FDS) insertion has been in-stent stenosis. Though previously studied in the short-term period, the long-term history of this complication has yet to be described. METHODS: We performed a retrospective cohort study of consecutive IAs treated with Pipeline Embolization Device (PED), with or without coiling, at our centre between September 2014 and December 2018 that had at least one digital subtraction angiogram (DSA) during follow-up. In-stent stenosis was measured from DSA images, and associated patient and procedural characteristics were analysed. RESULTS: 94 patients treated with PED for IA were identified. On initial DSA during follow-up, 52 patients (55.3%) had in-stent stenosis within the PED. Of these 52 patients, 17 had a second DSA during follow-up. In this 2nd DSA, improvement and/or stable in-stent stenosis was seen 16 patients (94.1%). One patient in this group had worsening in-stent stenosis had a vertebrobasilar junction FD stent. Of the patients without in-stent stenosis on initial DSA, 15 had a second DSA during follow-up. Only one of these patients (6.7%) had new appearance of in-stent stenosis (measuring 5%). Multivariate analysis found statin use to be predictive of in-stent stenosis (p = 0.020, Odds ratio = 0.279 and 95% confidence interval = 0.095-0.821). CONCLUSIONS: In-stent stenosis after FDS placement was seen in 53.2% of cases, which had between 1-50% of stenosis. 82.4% had resolution/improvement of their stenosis. Statin use was protective of in-stent stenosis.

Factors Associated With Decreased Accuracy of Modified Thrombolysis in Cerebral Infarct Scoring Among Neurointerventionalists During Thrombectomy.

Background and Purpose: The modified Thrombolysis in Cerebral Infarct (mTICI) score is used to grade angiographic outcome after endovascular thrombectomy. We sought to identify factors that decrease the accuracy of intraprocedural mTICI. Methods: We performed a 2-center retrospective cohort study comparing operator (n=6) mTICI scores to consensus scores from blinded adjudicators. Groups were also assessed by dichotomizing mTICI scores to 0­2a versus 2b­3. Results: One hundred thirty endovascular thrombectomy procedures were included. Operators and adjudicators had a pairwise agreement in 96 cases (73.8%). Krippendorff α was 0.712. Multivariate analysis showed endovascular thrombectomy overnight (odds ratio [OR]=3.84 [95% CI, 1.22­12.1]), lacking frontal (OR, 5.66 [95 CI, 1.36­23.6]), or occipital (OR, 7.18 [95 CI, 2.12­24.3]) region reperfusion, and higher operator mTICI scores (OR, 2.16 [95 CI, 1.16­4.01]) were predictive of incorrectly scoring mTICI intraprocedurally. With dichotomized mTICI scores, increasing number of passes was associated with increased risk of operator error (OR, 1.93 [95 CI, 1.22­3.05]). Conclusions: In our study, mTICI disagreement between operator and adjudicators was observed in 26.2% of cases. Interventions that took place between 22:30 and 4:00, featured frontal or occipital region nonperfusion, higher operator mTICI scores, and increased number of passes had higher odds of intraprocedural mTICI inaccuracy.

Middle Cerebral Artery Duplication: A Near Miss for Stroke Thrombectomy.

Middle cerebral artery (MCA) duplication is a rare anatomical arrangement where an anomalous MCA arises from the distal end of the internal carotid artery. If occluded, a duplicated MCA can present with significant deficits comparable to an occlusion of the M2 vessel without obvious findings on vessel imaging via computed tomography angiography (CTA) or magnetic resonance angiography. A female in her 30s with no past medical history presented with suspected acute stroke 8 hours after last known normal-featuring new-onset right-sided weakness, facial droop, and slurred speech, which corresponds to a National Institutes of Health Stroke Scale score of 13. Head CTA was interpreted as preserved patency of intracranial vessels. CT perfusion was suggestive of a large area of penumbra. Emergent cerebral angiography demonstrated MCA duplication on the left side with proximal occlusion of the M1 branch supplying the traditional M2 territory. Mechanical thrombectomy achieved grade TICI 2b reperfusion. Throughout her hospital stay, her aphasia started to resolve, and the patient was discharged to inpatient rehabilitation. This case presents a diagnostic challenge and learning point in identifying similar patients in the future. We suggest the clinician, given a high clinical suspicion for large vessel occlusion, even if CTA is negative, to continue with CT perfusion to not miss stroke in patients with MCA duplication. If CT perfusion shows substantial deficit in an MCA distribution, one must consider that the patient may have an MCA duplication.