Temporal Analysis of Postoperative Outcomes With or Without Intraoperative Motor Evoked Potentials and Somatosensory Evoked Potentials Monitoring for Intracranial Meningioma Surgery.

BACKGROUND: This study aimed to retrospectively assess results of intracranial meningioma surgery with or without intraoperative neuromonitoring (IONM) in a single institution. METHODS: Two cohorts (a historical cohort and a monitoring cohort) were collected for the analysis. Before IONM was introduced, a total of 107 patients underwent intracranial meningioma operation without IONM from January 2000 to December 2008 by one neurosurgeon (historical cohort). After IONM was introduced, a total of 99 patients with intracranial meningioma were operated under IONM between November 2018 and February 2023 by two neurosurgeons (monitoring cohort). A retrospective comparison was made on the complications from meningioma surgery between the two groups. RESULTS: In the monitoring cohort, warning signals of motor evoked potential (MEPs) or somatosensory evoked potential (SSEPs) were alarmed in 10 patients. Two of these 10 patients aborted the operation and eight of these 10 patients with warning signals underwent tumor resection. Of these eight patients, five showed postoperative morbidity. Five of 89 patients without warning signals developed neurological deficits. In the historical cohort, 14 of 107 patients showed postoperative morbidity or mortality. CONCLUSION: Even after successful resection of intracranial meningiomas prior to the advent of IONM, integration of MEPs and SSEPs monitoring yielded valuable insights for surgical teams during operative procedures.

Association of Bypass Surgery and Mortality in Moyamoya Disease.

Background Patients with moyamoya disease (MMD) have a high risk of stroke or death. We investigated whether extracranial to intracranial bypass surgery can reduce mortality by preventing strokes in patients with MMD. Methods and Results This nationwide retrospective cohort study encompassed patients with MMD registered under the Rare Intractable Diseases program via the Relieved Co-Payment Policy between 2006 and 2019, using the Korean National Health Insurance Service database. Following a 4-year washout period, landmark analyses were employed to assess mortality and stroke occurrence between the bypass surgery group and the nonsurgical control group at specific time points postindex date (1 month and 3, 6, 12, and 36 months). The study included 18 480 patients with MMD (mean age, 40.7 years; male to female ratio, 1:1.86) with a median follow-up of 5.6 years (interquartile range, 2.5-9.3; mean, 6.1 years [SD, 4.0 years]). During 111 775 person-years of follow-up, 265 patients in the bypass surgery group and 1144 patients in the nonsurgical control group died (incidence mortality rate of 618.1 events versus 1660.3 events, respectively, per 105 person-years). The overall adjusted hazard ratio (HR) revealed significantly lower all-cause mortality in the bypass surgery group from the 36-month landmark time point, for any stroke mortality from 3- and 6-month landmark time points, and for hemorrhagic stroke mortality from the 6-month landmark time point. Furthermore, the overall adjusted HRs for hemorrhagic stroke occurrence were beneficially maintained from all 5 landmark time points in the bypass surgery group. Conclusions Bypass surgery in patients with MMD was associated with a lower risk of all-cause and hemorrhagic stroke mortality and hemorrhagic stroke occurrence compared with nonsurgical control.

Analysis of sagittal parameters for easier and more accurate determination of cervical spine alignment.

Cross-sectional comparative study. This study aimed to analyze the role of cervical parameters, in terms of the perception process, when evaluating cervical sagittal balance on an X-ray image. Reports on the role of cervical parameters in the perception of cervical sagittal balance have not been made. The study included 4 board-certified neurosurgeons and 6 residents of a neurosurgical department. They were instructed to answer a total of 40 questions. The parameter that was the most helpful in deriving the answer was checked. The correct answer rate, dependency on the parameter, and correct answer contribution of the parameter were analyzed. Among the various parameters, 5 parameters [C2-7 angle (C2-7A), T1 slope minus cervical lordosis (T1s-CL), C2 slope (C2s), C7 slope (C7s), and C2-7 sagittal vertical axis) were selected. The simple parameter (C2s, C7s) has a higher dependency and correct answer contribution than the complex parameter (C2-7A, T1s-CL). The angular (C2-7A, T1s-CL, C2s, C7s) parameters have a higher dependency; however, both the length and angular parameters correct answer contribution were similar. The cervical parameters that have simpler properties were highly preferred and had a lower perception error.

The safety and effectiveness of lumbar drainage for cerebrospinal fluid leakage after spinal surgery.

PURPOSE: Cerebrospinal fluid (CSF) leakage is a frequent complication after spinal surgery. The lumbar drainage procedure (LDP) is the preferred method for early closure of a dural tear. This study was conducted to assess the safety and effectiveness of LDP after spinal surgery. MATERIALS AND METHODS: We retrospectively reviewed 122 patients (55 male and 67 female) who underwent LDP after spinal surgery between January 2010 and June 2021. LDP was performed on patients with suspected CSF leakage due to a dural tear during spinal surgery or in whom mixed-color CSF was observed in the hemo-drain after surgery. LDP was performed aseptically by a resident according to our institution's protocol, and the amount drained was from 200cc to 300cc per day. Absolute bed rest was maintained during the lumbar drainage period. The hemo-drain was opened to confirm that CSF was no longer mixed or oozing, at which time the lumbar drain was removed. Culture was performed at the drain tip when the lumbar drain was removed. RESULTS: The spinal surgery level was cervical in 23 patients, thoracic in 27 patients, and lumbar in 72 patients. The mean duration of the indwelling lumbar drain was 7.2 days (2 days-18 days), and the mean amount of drainage was 1198.2cc (100cc-2542cc). Among the 122 patients, the CSF leakage in 101 patients was resolved with the initial procedure, but 21 patients required re-insertion. Of those 21 patients, improper insertion due to a technical problem occurred in 15 patients, poor line fixation occurred in 2 patients, and CSF leakage was again observed after removal of the lumbar drain in 4 patients. In only 1 case was open surgery done after LDP because follow-up magnetic resonance imaging showed a suspected infection. During lumbar drainage, 76 patients used antibiotics, and 46 patients did not. Four patients showed bacterial growth in the tip culture, and 3 of them had been using antibiotics. All 4 of those patients were treated without complications and discharged. Among the 122 patients, 1 patient was discharged with left hemiparesis due to cerebral venous infarction (CVI) and hemorrhage after LDP, and 1 patient underwent re-operation because the CSF collection was not resolved. CONCLUSIONS: No major complications such as systemic infection, deep vein thrombosis, or aspiration pneumonia occurred during the lumbar drainage, except for 1 patient (0.8%) with CVI caused by over-drainage. One patient (0.8%) required open surgery after LDP, but no cases of systemic infection occurred while maintaining lumbar drainage, irrespective of antibiotic use. In conclusion, LDP is a safe and effective treatment for CSF leakage after spinal surgery.

Analysis of Factors Affecting Good Neovascularization After Indirect Bypass Surgery: A Two-center Retrospective Study.

OBJECTIVE: The purpose of this study was to analyze factors affecting good neovascularization after indirect bypass surgery. METHODS: From August 2000 to July 2020, postoperative image results and medical records of 132 patients (159 hemispheres) who underwent EDAS of indirect bypass surgery at two institutions were reviewed retrospectively. Based on DSA results, angiogenesis after indirect bypass was divided into "good" or "poor" according to the Matsushima criteria. STA flap length affecting GPN were analyzed in the entire group (n = 159) and a MMD group (n = 134). RESULTS: In the entire group, GPN after EDAS was observed in 94 (59.1%) hemispheres. Age, MMD, hypertension, and bone flap size were identified as significant factors in univariate analysis. Also, in the MMD group, 86 (64.2%) hemispheres showed GPN. Hypertension and bone flap size were significant factors in both univariate and multivariate analyses. Cutoff values of bone flap size and GPN were 47.91 cm2 in the entire group and the MMD group. CONCLUSIONS: In all patients who received EDAS, good postoperative neovascularization was significant in those with a young age, MMD, without hypertension, and large bone flap size. No hypertension and large bone flap size were meaningful factors in the MMD group. AUROC showed that an appropriate bone flap size was 47.91 cm2. However, a further controlled prospective study is needed.

Comparison of Single- and Multi-Echo Susceptibility-Weighted Imaging in Detecting Cerebral Arteriovenous Shunts: A Preliminary Study.

Purpose: To compare the sensitivities of T2-weighted image (T2WI) and susceptibility-weighted imaging (SWI) in detecting cerebral arteriovenous fistula (AVF), cerebral arteriovenous malformation (AVM), and carotid-cavernous sinus fistula (CCF), and to qualitatively evaluate single-echo SWI (s-SWI) and multi-echo SWI (m-SWI) in characterizing vascular lesions. Materials and Methods: From January 2016 to December 2021, cerebral angiography-proven lesions were recruited. The sensitivities of T2WI and SWI in detecting vascular lesions were compared using McNemar's test. Qualitative evaluations of s-SWI and m-SWI were categorized to be of poor, average, or good quality and compared using Fisher's exact test. Results: A total of 24 patients (mean age: 61 years, 12 female, and 12 male) were enrolled. Twenty patients underwent s-SWI or m-SWI, and four patients underwent both. AVF, AVM, and CCF were diagnosed in 10, 11, and 3 patients, respectively. SWI demonstrated higher sensitivity compared to that of T2WI (82.1% vs. 53.6%, p = 0.013). m-SWI showed better image quality compared to that of s-SWI (good quality, 83.3% vs. 25.0%, p = 0.009). Conclusion: SWI demonstrated a higher sensitivity for detecting cerebral arteriovenous shunts compared to that of T2WI. m-SWI exhibited better image quality compared to that of s-SWI in characterizing vascular lesions.

Tailored antiplatelet therapy in stent assisted coiling for unruptured aneurysms: a nationwide registry study.

BACKGROUND: Antiplatelet therapy, where regimens are tailored based on platelet function testing, has been introduced into neurointerventional surgery. This nationwide registry study evaluated the effect and safety of tailored antiplatelet therapy in stent assisted coiling for unruptured aneurysms compared with conventional therapy using a standard regimen. METHODS: This study enrolled 1686 patients in 44 participating centers who received stent assisted coiling for unruptured aneurysms between January 1, 2019 and December 31, 2019. The standard regimen (aspirin and clopidogrel) was used for all patients in the conventional group (924, 19 centers). The regimen was selected based on platelet function testing (standard regimen for clopidogrel responders; adding cilostazol or replacing clopidogrel with other thienopyridines (ticlopidine, prasugrel, or ticagrelor) for clopidogrel non-responders) in the tailored group (762, 25 centers). The primary outcome was thromboembolic events. Secondary outcomes were bleeding and poor outcomes (increase in modified Rankin Scale score). Outcomes within 30 days after coiling were compared using logistic regression analysis. RESULTS: The thromboembolic event rate was lower in the tailored group than in the conventional group (30/762 (3.9%) vs 63/924 (6.8%), adjusted OR 0.560, 95% CI 0.359 to 0.875, P=0.001). The bleeding event rate was not different between the study groups (62/762 (8.1%) vs 73/924 (7.9%), adjusted OR 0.790, 95% CI 0.469 to 1.331, P=0.376). Poor outcomes were less frequent in the tailored group (12/762 (1.6%) vs 34 (3.7%), adjusted OR 0.252, 95% CI 0.112 to 0.568, P=0.001). CONCLUSION: Tailored antiplatelet therapy in stent assisted coiling for unruptured aneurysms reduced thromboembolic events and poor outcomes without increasing bleeding.

Detection of cerebral aneurysm and intracranial vertebral dissection using non-enhanced magnetic resonance imaging in emergency setting: Emphasis on magnitude image of susceptibility-weighted image.

PURPOSE: To evaluate image features and diagnostic performance of susceptibility-weighted image (SWI) in detection of intracranial vertebral artery dissection (VAD) and unruptured intracranial aneurysm (UIA). MATERIALS AND METHODS: From January 2015 to December 2021, symptomatic patients who underwent 3.0 T MR SWI were recruited. For study group, transfemoral cerebral angiography-proven lesions were included, while 1:1 matched control group with MR angiography were included. Image features of SWI were evaluated. Diagnostic performance and interobserver agreements were calculated for detecting VAD with stenosis and UIA greater than 7 mm. RESULTS: Total of 110 patients (mean age: 60.92 years, female: 60/110) were included. In the study group (N = 55), 21 patients (38.2%) had VAD, while 34 patients (61.8%) had UIA. For SWI-detectable VAD, larger parent artery (PA)-dilatation ratio was observed (1.36 vs. 1.84, p = 0.034). For SWI-detectable UIA, larger PA-dome ratio (1.32 vs. 1.90, p = 0.020) and larger PA-height ratio (1.25 vs. 1.77, p = 0.005) were observed. The diagnostic performance and kappa values for VAD with stenosis were as follow: sensitivity: 91.7 (95% CI: 61.5-99.8); specificity: 93.9 (95% CI: 87.2-97.7); к: 0.80. The diagnostic performance for UIA larger than 7 mm were as follow: sensitivity: 87.5 (95% CI: 47.4-99.7); specificity: 95.1 (95% CI: 88.9-98.4); к: 0.73. CONCLUSION: SWI-detectable lesions were VAD with larger PA-dilatation ratio, and UIA with larger PA-dome ratio, and PA-height ratio. SWI was able to accurately detect VAD with stenosis and UIA larger than 7 mm with substantial interobserver agreements.

Analysis of failed mechanical thrombectomy with a focus on technical reasons: Ten years of experience in a single institution.

OBJECTIVE: Mechanical thrombectomy (MT) is an effective treatment for patients suffering from acute ischemic stroke secondary to large vessel occlusion. However, recanalization failure rates of interventions were about 20% in literature studies. We report our experience of unsuccessful MT with a focus on technical reasons. METHODS: From December 2010 to June 2021, six hundred eight patients with acute ischemic stroke due to large artery occlusion received MT using a stent retriever with or without an aspiration catheter in our institution. We divided the reasons for failure into six categories. We analyzed the reasons for failure by dividing our experience time into 3 periods. RESULTS: A total of 608 cases of thrombectomy for large vessel occlusion were identified in the study period. The successful recanalization rate was 90.4%. In most of the cases (20/57, 35%), the thrombus persisted despite several passes, and the second most common cause was termination of the procedure even after partial recanalization (10/57, 18%). Similar proportions of in-stent occlusion, distal embolization, and termination due to vessel rupture were observed. On analysis of three periods, the successful recanalization rate improved over time. CONCLUSIONS: MT fails due to various reasons, and intracranial artery stenosis is the main cause of MT failure. With the development of rescue techniques, the failure rate has gradually decreased. Further development of new devices and techniques could improve the recanalization rates.

Comparison of Neuroform Atlas Stent-Assisted Coiling and Coiling Alone in Ruptured Intracranial Aneurysms: A Propensity Score Matching Analysis.

BACKGROUND: Although Neuroform Atlas stent is commonly used in stent-assisted coiling (SAC) to treat ruptured intracranial aneurysms (RIA), its safety and efficacy remain controversial. OBJECTIVE: To assess the safety and efficacy of SAC using Neuroform Atlas for treating RIA compared with coiling alone by performing a propensity score matching analysis. METHODS: RIA treated with coiling alone and SAC between January 2017 and May 2021 were retrospectively reviewed. Demographics, periprocedural complication rates, angiographic outcomes, and clinical outcomes of the SAC using Neuroform Atlas group and the coiling-alone group were analyzed with 1:1 propensity score matching. RESULTS: A total of 375 aneurysms were enrolled, and 274 (63.1%) aneurysms were treated with coiling alone. In total, 101 (26.9%) aneurysms were treated with SAC, and Neuroform Atlas stent was used in 71 aneurysms. In propensity score matching, the SAC using Neuroform Atlas group showed higher incidence of complete occlusion (69.0% vs 56.3%, P = .029), lower rate of recanalization (11.3% vs 25.4%, P = .011), and lesser need for retreatment (7.0% vs 16.9%, P = .016) compared with the coiling-alone group. However, there were no significant differences in periprocedural complications such as intraprocedural thrombosis or postprocedural cerebral infarct between the 2 groups. CONCLUSION: The use of Neuroform Atlas is safe and effective for SAC in RIA with comparable procedure-related complication rates but better angiographic outcome in comparison with coiling alone.

Failure to Obtain Baseline Signals of Transcranial Motor-Evoked Potentials in Spine Surgery: Analysis of the Reasons.

OBJECTIVE: Among the various intraoperative neurophysiologic monitoring (IONM) techniques, transcranial motor-evoked potential (Tc-MEP) has recently become the most widely used method to monitor motor function. However, we often find that Tc-MEP is not sufficiently detected at the start of surgery. Therefore, we aimed to analyze the reasons and risk factors for not detecting sufficient baseline signal of Tc-MEP from the beginning of spinal surgery. METHODS: We categorized IONM data from 1058 patients who underwent spine surgeries at a single institution from 2014 to 2020 and categorized them into 2 groups: 1) "poor MEP" if Tc-MEP could not be sufficiently obtained and 2) "normal MEP" if Tc-MEP could be sufficiently obtained from the surgery. We analyzed the patient's age, gender, underlying disease, operation type, level numbers, baseline motor function, existence of pathologic reflex, myelopathy, and duration from the onset and clinical diagnosis. RESULTS: The rate of failure to obtain sufficient baseline Tc-MEP signals in spine surgery was 21.8% (231/1058). Multivariate analysis showed significant associations of existence of diabetes mellitus, myelopathy, thoracic spine surgery, baseline motor deficit and tumor, and trauma disease with loss of meaningful and interpretable signals in baseline Tc-MEP (P < 0.05). Only 15 of 231 patients (6.4%) showed a trend of signal recovery after decompression procedures. CONCLUSIONS: Various factors (myelopathy, diabetes mellitus, thoracic surgery, baseline motor deficit, tumor, and trauma) were closely related to not obtaining sufficient baseline signals for Tc-MEP. When operating on patients with these considerations, we need to consider the efficacy and usefulness of Tc- MEP.

Screw Insertional Torque Measurement in Spine Surgery: Correlation With Bone Mineral Density and Hounsfield Unit.

OBJECTIVE: Achieving successful fusion during spine surgery is dependent on rigid pedicle screw fixation. To assess fixation strength, the insertional torque can be measured during intraoperative screw fixation. This study aimed to explore the technical feasibility of measuring the insertional torque of a pedicle screw, while investigating its relationship with bone density. METHODS: Thoraco-lumbar screw fixation fusion surgery was performed on 53 patients (mean age, 65.5 ± 9.8 years). The insertional torque of 284 screws was measured at the point passing through the pedicle using a calibrated torque wrench, with a specially designed connector to the spine screw system. The Hounsfield units (HU) value was determined by assessing the trabecular portion of the index vertebral body on sagittal computed tomography images. We analyzed the relationship between the measured insertional torque and the following bone strength parameters: bone mineral density (BMD) and HU of the vertebral body. RESULTS: The mean insertion torque was 105.55 ± 58.08 N∙cm and T-score value (BMD) was -1.14 ± 1.49. Mean HU value was 136.37 ± 57.59. Screw insertion torque was positively correlated with BMD and HU in whole patients. However, in cases of osteopenia, all variables showed very weak correlations with insertional torque. In patients with osteoporosis, there was no statistically significant correlation between BMD and torque strength; HU showed a significant correlation. CONCLUSION: The insertional torque of screw fixation significantly correlated with bone density (BMD and HU). HU measurements showed greater clinical significance than did BMD values in patients with osteoporosis.

Factors Related to Mechanical Thrombectomy Failure in Large Vessel Occlusion: A Propensity Score Matching Analysis.

OBJECTIVE: Mechanical thrombectomy (MT) is an effective treatment for large vessel occlusion (LVO) with a high successful recanalization (SR) rate. However, MT fails in a proportion of patients, leading to poor clinical outcomes. We analyzed the factors associated with the failure of MT. METHODS: A total of 648 consecutive patients with MT were enrolled. MT failure was defined as 0,1, or 2a of modified Thrombolysis in Cerebral Infarction (mTICI) grade. Failed MTs were divided into 3 categories, reaching failure, passage failure, and recanalization failure (RF). Various factors in RF and SR groups were analyzed with 1: 1 propensity score matching. RESULTS: Failed MT was observed in 97 patients (14.3%). Among them, 69 patients (10.2% of the entire cohort, 71.1% of the failed MT group) were included in the RF group. Propensity matching analysis with 69 patients in each group showed that the RF group had a higher rate of residual intracranial atherosclerotic stenosis (ICAS) than the SR group (30.4% vs. 14.5% P = 0.003). The rates of 4 or more passages and no change of method were significantly higher in the RF group than in the SR group (34.8% vs. 13.0%; P = 0.001 and 28.9% vs. 8.7%; P = 0.001). CONCLUSION: The failure rate for all of the MT was approximately 15%, and RF accounted for more than 70% of the failed MT. RF was associated with residual ICAS. In cases with RF, even in repeated attempts for recanalization, an alteration of the thrombectomy method should be considered.

Analysis of Parameters That Can Predict the Cervical Sagittal Vertical Axis in Cervical Fusion Surgery.

OBJECTIVE: The absolute value of the cervical sagittal parameters cannot be guaranteed with certainty on all follow-up cervical radiographs. With the assumption that neck posture changes can occur at any time at each follow-up radiographic session, we examined whether the sagittal parameters change meaningfully and identified the factors most closely related to the C2-C7 sagittal vertical axis (SVA). METHODS: We enrolled 200 patients who had undergone either anterior cervical fusion (n = 100) or posterior cervical fusion (n = 100). The craniovertebral angle (CVA), mandible angle (MA), occipital slope (Os), C2 slope (C2s), C7 slope (C7s), and C2-C7 SVA were measured on 2 different follow-up radiographs after surgery. The C2-C7 angle (C2-C7A) and changes (Δ) in the sagittal parameters between the 2 radiographs were then calculated. RESULTS: The ΔC2s and ΔCVA showed a very strong correlation with the ΔC2-C7 SVA (r = |0.70-0.93|). An independent t test showed a statistically significant difference for multiple sagittal parameters (i.e., ΔMA, ΔOs, ΔC2s, ΔC7s, and ΔCVA) between the large and small ΔC2-C7 SVA groups. In contrast, the change in the C2-C7A was without statistical significance. A stepwise multivariate regression analysis revealed a high adjusted R2 value (0.841) between the ΔC2-C7 SVA and 2 parameters (standardized coefficient: ΔCVA, -0.563; ΔC2s, -0.398). CONCLUSIONS: During cervical fusion surgery, the CVA was the most predictable parameter reflecting the C2-C7 SVA in various analyses. The upper cervical parameters (Os and C2s) provided more explanatory power regarding the C2-C7 SVA changes than did the lower cervical parameter (C7s) or the presence of cervical lordosis (C2-C7A).

Hounsfield unit measurement method and related factors that most appropriately reflect bone mineral density on cervical spine computed tomography.

OBJECTIVE: Our study's purpose was to determine the most reliable Hounsfield unit (HU) measurement method to reflect bone mineral density (BMD) on cervical spine computed tomography (CT) and to identify any factors that influence these results. MATERIALS AND METHODS: We retrospectively analyzed 439 consecutive patients with mild head and neck injuries. Mean HU values of the C2-C7 vertebra were determined on each sagittal, coronal, and axial CT image. Correlation patterns were analyzed between the HU value and corresponding dual-energy X-ray absorptiometry (DXA) in the lumbar vertebra (T-score) and femoral neck (T-score). A sub-group analysis was performed according to patient age, sex, and degree of spinal degeneration. RESULTS: The correlation coefficients for HU and DXA ranged from 0.52 to 0.65 in all cervical segments. A simple linear regression analysis revealed the following formula: T-score = 0.01 × (HU) - 4.55. The mean HU values for osteopenia and osteoporosis were 284.0 ± 63.3 and 231.5 ± 52.8, respectively. The ROC curve indicated that the HU method has a sensitivity of 89.2% and specificity of 88.7% to diagnose osteoporosis. The HU measurement showed a high correlation value (range: r = 0.64-0.70) with spine DXA score regardless of the degree of degeneration or patient age or sex. CONCLUSION: HU values using the upper two cervical vertebrae (C2 and C3) reflected a more reliable BMD level than other segments. Additionally, the HU of cervical CT provided reliable information regardless of measurement plane, age or sex, and degree of degeneration.

Analyzing the Significance of T1 Slope minus Cervical Lordosis in Patients with Anterior Cervical Discectomy and Fusion Surgery.

OBJECTIVE: Accurate measurement of T1 slope (a component of T1s minus cervical lordosis [CL]) is often constrained by anatomical limitations. In this situation, efforts should be made to find the exact meaning of T1s-CL and whether there are any alternatives to it. METHODS: We enrolled 117 patients who received two-level anterior cervical discectomy and fusion (ACDF). Occipital slope, C2 slope (C2s), C7 slope (C7s), T1, O-C2 angle (O-C2A), C2-7 angle (C2-7A), O-C7 angle (O-C7A), T1s-CL, C7-T1 angle (C7-T1A), and C2-7 sagittal vertical axis were measured. We determined 16° (T1s-CL) as the reference point for dividing subjects into the mismatch group and the balance group, and a comparative analysis was performed. RESULTS: The mean value of C7-T1A was constantly maintained within 2.6° peri-operatively. In addition, C2s and T1s-CL showed the same absolute change (Δ|0.8|°). The mean values of T1s-CL of the mismatch and balance groups were 23.0° and 7.6°, respectively. The five factors with the largest differences between the two groups were as follows : C2s (Δ13.3°), T1s-CL (Δ15.4°), O-C2A (Δ8.7°), C2-7A (Δ14.7°), and segmental angle (Δ7.9°) before surgery. Only four factors showed statistically significant change between the two groups after ACDF : T1s-CL (Δ4.0° vs. Δ0.2°), C2s (Δ3.2° vs. Δ0.7°), O-C2A (Δ2.6° vs. Δ1.3°), C2-7A (Δ6.3° vs. Δ1.3°). A very strong correlation between T1s-CL and C2s was also found (r=|0.88-0.96|). CONCLUSION: C2s itself may be the essential key to represent T1s-CL. The amounts and directions of change of these two factors (T1s-CL and C2s) were also almost identical. The above phenomenon was re-confirmed once again through the correlation analysis.

Modified Orbitozygomatic Approach for Resecting a Parasellar Tumor in a Single Institution.

BACKGROUND: Modified orbitozygomatic craniotomy is characterized by simplicity and wide exposure. The purpose of the present study was to describe a modified orbitozygomatic approach without resecting the zygomatic arch for large parasellar tumor surgeries. METHODS: Between April 2016 and December 2019, seven patients with parasellar tumor underwent surgiest with a modified orbitozygomatic approach. Surgical procedures, clinical outcomes, and complications were analyzed. RESULTS: This study included 3 meningiomas, 2 pituitary adenomas, 1 chondrosarcoma, and 1 schwannoma. Modified orbitozygomatic craniotomy provides a wider surgical freedom in the opticocarotid and prechiasmatic cistern than frontotemporal craniotomy without orbitotomy, Total, subtotal, and partial resections were achieved for 3, 2, and 2 patients, respectively. Reasons for partial resections were tight adhesion to the carotid artery and encasing of the carotid artery. Permanent morbidities developed in one patient with 3rd nerve palsy and one patient with hemiparesis. CONCLUSION: Modified orbitozygomatic approach can provide the shortest access to the interpeduncular cistern with a minimum brain retraction. Surgeons who experience surgical challenge during the conventional approach for parasellar tumor resection are recommended to learn the modified orbitozygomatic approach.

Systemic Inflammation Response Index and Systemic Immune-Inflammation Index Are Associated with Clinical Outcomes in Patients Treated with Mechanical Thrombectomy for Large Artery Occlusion.

BACKGROUND: Inflammation plays a pivotal role in acute ischemic stroke, and various inflammatory markers are known to predict prognosis of acute ischemic stroke. This study aimed to evaluate the prognostic value of systemic inflammation response index (SIRI) and systemic immune-inflammation index (SII) after mechanical thrombectomy (MT) for acute ischemic stroke caused by large artery occlusion. METHODS: The study enrolled 440 patients who underwent MT for large artery occlusion. SIRI and SII were calculated using laboratory data on admission. Prognosis was estimated with modified Rankin Scale at 3 months, and favorable clinical outcome was defined by a modified Rankin Scale score of 0-2. Receiver operating characteristic analysis was used to calculate the optimal cutoff values of SIRI and SII for predicting clinical outcome. Multivariate analysis was used to assess the relationship of SIRI and SII with clinical outcome. RESULTS: In receiver operating characteristic analysis, the optimal cutoff values for SIRI and SII were 2.9 and 853, respectively (area under the curve 0.799, 95% confidence interval [CI] 0.756-0.843, P < 0.001 and area under the curve 0.679, 95% CI 0.643-0.745, P < 0.001, respectively). Multivariate analysis revealed that SIRI <2.9 (odds ratio 2.27, 95% CI 1.29-5.17, P = 0.019) and SII <853 (OR 1.82, 95% CI 1.16-3.10, P = 0.031) were independent predictors of favorable clinical outcome after MT. CONCLUSIONS: Decreased SIRI and SII were associated with favorable clinical outcome after MT. SIRI and SII represent potential prognostic factors in patients undergoing MT for large artery occlusion.

Significance of Cervical Spine Computed Tomography Hounsfield Units to Predict Bone Mineral Density and the Subsidence After Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: This study was a retrospective review. OBJECTIVE: The purpose of this study was to investigate the correlation analysis between Hounsfield units (HU) and dual x-ray absorptiometry (DXA) based on the clinical results of patients who underwent anterior cervical discectomy and fusion (ACDF) surgery. SUMMARY OF BACKGROUND DATA: There is no technique to directly measure bone mineral density (BMD) in the cervical spine. As computed tomography is a very popular preoperative planning modality, using the HU value from that analysis to predict osteoporosis is important for patient outcomes and applications in the clinical field. MATERIALS AND METHODS: We reviewed the records for 235 patients who underwent 1-level (n=120) or 2-level (n=115) ACDF surgery. In the 1-level ACDF group, the HU was measured from C3 to C6 vertebra, while that for the 2-level ACDF group was measured from 3 surgical index vertebrae. The correlation patterns were analyzed with the corresponding DXA (T-score) for each patient. Subsidence of fusion segment was defined as change in distance between plate-tip and upper (lower) margin of the vertebra (index level) after 4 months of follow-up. In addition, to determine the relevant factors that influence fusion segment subsidence, other preoperative (C2 slope, C7 slope, C2-C7 angle, and C2-C7 sagittal vertical axis) and postoperative parameters (coronal angle and segmental angle change) were measured. RESULTS: The correlation coefficient between HU and DXA ranged from 0.57 to 0.71 in the 1-level ACDF group and from 0.59 to 0.66 in the 2-level ACDF group. The correlation between HU and DXA was statistically significant regardless of the degree of anterior osteophyte (r=-0.65 to 0.78). Total subsidence height was 3.8 mm after ACDF, and both HU and DXA were statistically correlated with total subsidence (r=0.26-0.28). In multivariate analysis, HU (middle vertebra) value was statistically associated with the degree of total subsidence. The high-subsidence group (≥4.5 mm) showed smaller HU values (284.1 vs. 316.0) and T-scores (-0.5 vs. 0.1) compared to the low-subsidence group (<4.5 mm). The discrepancy group, defined as cases with excess plate shift on 1 side, also showed smaller HU values (260.4 vs. 312.4) and higher degrees of total subsidence than the matched group. CONCLUSIONS: The correlation between HU in cervical computed tomography and lumbar DXA (T-score) was statistically significant in both 1-level and 2-level ACDF. The level of BMD (HU or DXA) is a very important factor for clinically determining the amount and regularity of subsidence after ACDF. Therefore, HU can be a good alternative assessment to accurately reflect as much of the BMD degree as DXA in the cervical spine.

The Long-Term Functional Effect of Thrombectomy on Patients with Middle Cerebral Artery Occlusion Who Exhibit Moderate to Severe Disability.

Background and Objectives: Endovascular thrombectomy (EVT is an emerging gold standard treatment for acute cerebral infarction and may allow functional improvement after subacute cerebral infarction. However, the long-term functional benefits of EVT in patients with moderate to severe disability remain unclear. We investigated the effects of EVT on the activities of daily living (ADL), handicap, gait, and eating in patients with middle cerebral artery (MCA) occlusion who exhibited moderate to severe disability (score of 3-5 on the modified Rankin scale (mRS)) due to stroke, up to six months after onset. Materials and Methods: This retrospective longitudinal case-control study assessed 45 patients with MCA occlusion who exhibited moderate to severe disability (mRS score ≥ 3): 15 underwent EVT and 30 served as controls. Clinical assessments were conducted at two weeks (12-16 days), four weeks (26-30 days), and six months (180-210 days) after stroke onset. Functional assessments comprised the Korean version of the modified Barthel index (MBI), mRS, functional ambulation category (FAC), and dysphagia outcome severity scale (DOSS) to assess disability, handicap, gait, and eating. Results: The MBI, mRS, FAC, and DOSS scores all improved significantly (all p < 0.05) in the EVT group, compared to the controls. Conclusions: EVT has favorable effects on performing routine ADL, the handicap itself, walking, and eating. Therefore, EVT is recommended for patients with acute MCA occlusion, including those with severe disability at the initial assessment.