A Bayesian estimation method for cerebral blood flow measurement by area-detector CT perfusion imaging.

PURPOSE: Bayesian estimation with advanced noise reduction (BEANR) in CT perfusion (CTP) could deliver more reliable cerebral blood flow (CBF) measurements than the commonly used reformulated singular value decomposition (rSVD). We compared the efficacy of CBF measurement by CTP using BEANR and rSVD, evaluating both relative to N-isopropyl-p-[(123) I]- iodoamphetamine (123I-IMP) single-photon emission computed tomography (SPECT) as a reference standard, in patients with cerebrovascular disease. METHODS: Thirty-one patients with suspected cerebrovascular disease underwent both CTP on a 320 detector-row CT system and SPECT. We applied rSVD and BEANR in the ischemic and contralateral regions to create CBF maps and calculate CBF ratios from the ischemic side to the healthy contralateral side (CBF index). The analysis involved comparing the CBF index between CTP methods and SPECT using Pearson's correlation and limits of agreement determined with Bland-Altman analyses, before comparing the mean difference in the CBF index between each CTP method and SPECT using the Wilcoxon matched pairs signed-rank test. RESULTS: The CBF indices of BEANR and 123I-IMP SPECT were significantly and positively correlated (r = 0.55, p < 0.0001), but there was no significant correlation between the rSVD method and SPECT (r = 0.15, p > 0.05). BEANR produced smaller limits of agreement for CBF than rSVD. The mean difference in the CBF index between BEANR and SPECT differed significantly from that between rSVD and SPECT (p < 0.001). CONCLUSIONS: BEANR has a better potential utility for CBF measurement in CTP than rSVD compared to SPECT in patients with cerebrovascular disease.

Carotid Plaque Diagnosis With 3-Dimensional Computed Tomography Angiography: A Comparison With Magnetic Resonance Imaging-Based Plaque Diagnosis.

OBJECTIVE: Although a qualitative diagnosis of plaque causing carotid stenosis has been attempted with carotid computed tomography angiography (CaCTA), no clear findings have been reported. We examined the correlation between the plaque CT values and plaque images obtained by magnetic resonance imaging to derive a qualitative diagnosis of the plaque using CaCTA. METHODS: Preoperative CaCTA images acquired from patients stented for carotid stenosis were retrospectively analyzed with respect to magnetization-prepared rapid acquisition with gradient echo and time-of-flight magnetic resonance angiography data. Carotid plaques in the stenosed region were quantified in terms of CT density and the plaque/muscle ratio (magnetization-prepared rapid acquisition with gradient echo), and correlations between these 2 features were determined. Plaques were classified as stable or unstable based on the plaque/muscle ratio, with the smallest plaque/muscle ratio observed among plaques positive for intraplaque hemorrhage set as the cutoff value (1.76). RESULTS: A total of 165 patients (179 plaques) were included. Perioperative complications included minor stroke (n = 3), major stroke (n = 1, fatal), and hyperperfusion (n = 2). The correlation between CT density and the plaque/muscle ratio was nonlinear ( P = 0.0139) and negative ( P < 0.0001). The cutoff point (1.76) corresponded to a CT density of 83 HU, supporting this value as a standard reference for plaque stability. CONCLUSIONS: Computed tomography density exhibits a nonlinear ( P = 0.0139) and highly negative correlation ( P < 0.0001) with the plaque/muscle ratio. Our results demonstrate that plaque characteristics can be meaningfully diagnosed based on CaCTA image data.

Risk of postoperative scalp necrosis in the occipital artery region after posterior cranial fossa surgery.

Ischemia-induced postoperative scalp necrosis in the superficial temporal artery (STA) region is known to occur after STA-middle cerebral artery anastomoses. However, no reports have evaluated the risk of postoperative scalp necrosis in the occipital artery (OA) region. This study examined the surgical procedures that pose a risk for postoperative scalp necrosis in the OA region following posterior cranial fossa surgery. Patients who underwent initial posterior fossa craniotomy at our institution from 2015 to 2022 were included. Clinical information was collected using medical records. Regarding surgical procedures, we evaluated the incision design and whether a supramuscular scalp flap was prepared. The supramuscular scalp flap was defined as a scalp flap dissected from the sternocleidomastoid and/or splenius capitis muscles. A total of 392 patients were included. Postoperative scalp necrosis occurred in 19 patients (4.8%). There were 296 patients with supramuscular scalp flaps, and supramuscular scalp flaps prepared in all 19 patients with postoperative necrosis. Comparing incision designs among patients with supramuscular scalp flap, a hockey stick-shaped scalp incision caused postoperative necrosis in 14 of 73 patients (19.1%), and the odds of postoperative scalp necrosis were higher with the hockey stick shape than with the retro-auricular C shape (adjusted odds ratio: 12.2, 95% confidence interval: 3.86-38.3, p = 0.00002). In all the cases, ischemia was considered to be the cause of postoperative necrosis. The incidence of postoperative necrosis is particularly high when a hockey stick-shaped scalp incision is combined with a supramuscular scalp flap.

Osteocompatibility of Si3N4-coated carbon fiber-reinforced polyetheretherketone (CFRP) and hydroxyapatite-coated CFRP with antibiotics and antithrombotic drugs.

This study used a rabbit model to investigate the osteocompatibility of Si3N4-coated carbon fiber-reinforced polyetheretherketone (CFRP) and hydroxyapatite (HA)-coated CFRP with antibiotics (vancomycin [VCM]) and antithrombotic drugs (polyvinylpyrrolidone [PVP]). HA-coated cylindrical CFRP implants were used as the controls (HA), and HA-coated implants treated with VCM and PVP were prepared (HA-VP) as the test groups; a cylindrical CFRP coated with Si3N4 was also prepared (SiN). Ten implants from each group were randomly inserted into the femoral diaphysis of rabbits. The pull-out test, radiological analysis using micro-computed tomography (µ-CT), and histological analysis were performed. The pull-out strength of the SiN group was lower than that of the HA group. µ-CT analysis revealed that the amount of bone formation around the implant in the SiN group was inferior to that in the HA group. Conversely, the HA-VP group had equivalent pull-out strength and bone formation as analyzed by µ-CT compared to the HA group. In conclusion, the additional surface treatment of the HA-coated CFRP with VCM and PVP provided sufficient bone fixation and formation.

Optimizing vancomycin release from novel carbon fiber-reinforced polymer implants with small holes: periprosthetic joint infection treatment.

Periprosthetic joint infection (PJI) is a catastrophic complication after total hip arthroplasty. A new drug-loaded carbon fiber-reinforced polymer (CFRP) prosthesis with a sustained drug-release mechanism is being developed for one-stage surgery. We aimed to examine the diffusion dynamics of vancomycin from vancomycin paste-loaded CFRP implants. The differences in the in vitro diffusion dynamics of vancomycin paste were investigated using the elution test by varying parameters. These included the mixing ratio of vancomycin and distilled water (1:0.8, 1:1.2, and 1:1.4) for vancomycin paste, and hole diameter (1 mm and 2 mm) on the container. The in vivo diffusion dynamics were investigated using a rabbit model with vancomycin-loaded CFRP implants placed subcutaneously. The in vitro experiments showed that the diffusion effect of vancomycin was highest in the parameters of vancomycin paste with distilled water mixed in a ratio of 1:1.4, and with a 2 mm hole diameter. The in vivo experiments revealed diffusion dynamics similar to those observed in the in vitro study. The drug diffusion effect tended to be high for vancomycin paste with a large water ratio, and a large diameter of holes. These results indicate that the drug diffusion dynamics from a CFRP implant with holes can be adjusted by varying the water ratio of the vancomycin paste, and the hole size on the CFRP implant.

λ stenting: a novel technique for posterior communicating artery aneurysms with fetal-type posterior communicating artery originating from the aneurysm dome.

PURPOSE: Endovascular treatment of posterior communicating artery aneurysms with fetal-type posterior communicating artery originating from the aneurysm dome is often challenging because, with conventional techniques, dense packing of aneurysms for posterior communicating artery preservation is difficult; moreover, flow-diversion devices are reportedly less effective. Herein, we describe a novel method called the λ stenting technique that involves deploying stents into the internal carotid artery and posterior communicating artery. METHODS: Between January 2018 and September 2020, the λ stenting technique was performed to treat eight consecutive cases of aneurysms. All target aneurysms had a wide neck (dome/neck ratio < 2), a fetal-type posterior communicating artery with hypoplastic P1, and a posterior communicating artery originating from the aneurysm dome. The origin of the posterior communicating artery from the aneurysm, relative to the internal carotid artery, was steep (< 90°: V shape). RESULTS: The maximum aneurysm size was 8.0 ± 1.9 mm (6-12 mm). The average packing density (excluding one regrowth case) was 32.7 ± 4.2% (26.8-39.1%). Initial occlusion was complete occlusion in 6 (75.0%) patients and neck remnants in 2 (25.0%) patients. Follow-up angiography was performed at 18.4 ± 11.6 months (3-38 months). There were no perioperative complications or reinterventions required during the study period. CONCLUSION: The λ stenting technique enabled dense coil packing and preservation of the posterior communicating artery. This technique enabled safe and stable coil embolization. Thus, it could become an alternative treatment option for this sub-type of intracranial aneurysms.

Efficacy of the Flow Re-direction Endoluminal Device for cerebral aneurysms and causes of failed deployment.

PURPOSE: The Flow Re-direction Endoluminal Device (FRED) has recently become available for flow diversion in Japan. We have encountered cases that failed to deploy the FRED. In this study, we report our initial experience with the FRED for cerebral aneurysms and clarify the causes of failed FRED deployment. METHODS: A retrospective data analysis was performed to identify patients treated with the FRED between June 2020 and March 2021. Follow-up digital subtraction angiography was performed at 3 and 6 months and assessed using the O'Kelly-Marotta (OKM) grading scale. RESULTS: Thirty-nine aneurysms in 36 patients (average age: 54.4 years) were treated with the FRED. The average sizes of the dome and neck were 9.9 mm and 5.2 mm, respectively. In nine patients, additional coiling was performed. In one patient (2.6%), proximal vessel injury caused direct carotid-cavernous fistula during deployment. Ischaemic complications were encountered in one patient (2.6%) with transient symptoms. Angiographic follow-up at 6 months revealed OKM grade C or D in 86.6% of patients. FRED deployment was successful in 35 (92.1%) procedures. In the failure group, the differences between the FRED and the minimum vessel diameter (P = 0.04) and the rate of the parent vessel having an S-shaped curve (P = 0.04) were greater than those in the success group. CONCLUSIONS: Flow diversion using the FRED is effective and safe for treating cerebral aneurysms. The use of the FRED for patients with an S-shaped curve in the parent vessel and oversizing of more than 2 mm should be considered carefully.

A multicenter prospective registry of Borden type I dural arteriovenous fistula: results of a 3-year follow-up study.

PURPOSE: Although intracranial dural arteriovenous fistula (DAVF) without retrograde leptomeningeal venous drainage (Borden type I) is reported to have a benign nature, no study has prospectively determined its clinical course. Here, we report a 3-year prospective observational study of Borden type I DAVF. METHODS: From April 2013 to March 2016, consecutive patients with DAVF were screened at 13 study institutions. We collected data on baseline characteristics, clinical symptoms, angiography, and neuroimaging. Patients with Borden type I DAVF received conservative care while palliative intervention was considered when the neurological symptoms were intolerable, and were followed at 6, 12, 24, and 36 months after inclusion. RESULTS: During the study period, 110 patients with intracranial DAVF were screened and 28 patients with Borden type I DAVF were prospectively followed. None of the patients had conversion to higher type of Borden classification or intracranial hemorrhage during follow-up. Five patients showed spontaneous improvement or disappearance of neurological symptoms (5/28, 17.9%), and 5 patients showed a spontaneous decrease or disappearance of shunt flow on imaging during follow-up (5/28, 17.9%). Stenosis or occlusion of the draining sinuses on initial angiography was significantly associated with shunt flow reduction during follow-up (80.0% vs 21.7%, p = 0.02). CONCLUSION: In this 3-year prospective study, patients with Borden type I DAVF showed benign clinical course; none of these patients experienced conversion to higher type of Borden classification or intracranial hemorrhage. The restrictive changes of the draining sinuses at initial diagnosis might be an imaging biomarker for future shunt flow reduction.

Numerical analysis evaluation of artificial joints.

Artificial joints are exposed to loads on a daily basis. Loads on the bone through the artificial joint and the joint's sliding surface shear force may cause implant fixation failure, fatigue fractures, wear of the bearing and foreign body reactions. Artificial joints can experience sudden internal damage, which can be fatal if it occurs during activities performed at high altitudes or in water. The standard design hip prosthesis has a metal femoral stem. Most stem fractures are caused at the proximal one third of the stem by fatigue due to repetitive loading. Femoral stem neck fractures can also occur. To eliminate in vivo prosthesis failures, safety performance preclinical studies evaluate stem body and neck breakage. However, the development of new femoral stems via prototyping and fatigue test verification would require excessive time and money. Therefore, evaluation methods based on numerical analyses, such as finite element analysis (FEA), have been introduced to simulate tests on actual machines. Fatigue strength design verification using FEA can efficiently identify a design that can pass International Organization for Standardization fatigue tests. FEA may also aid with composite implant development by enabling efficient preclinical testing to prove safety using minimal actual fatigue testing. Once a biological safety study of a composite material is performed, a clinical trial can prove its clinical efficacy and safety and device regulatory approval can be requested. This review was created based on a translation of the Japanese review written in the Japanese Journal of Artificial Organs in 2020 (Vol. 49, No. 3, pp. 195-198), with adding some additional contents and references.

Posterior condylar canal dural arteriovenous fistula treated with transvenous embolization through the deep cervical vein.

The posterior condylar vein is an emissary vein that connects the extracranial and intracranial venous systems through the posterior condylar canal (PCC). Dural arteriovenous fistulas (DAVF) of the PCC are rare, and only seven cases have been reported. Transvenous embolization (TVE) is the first-line treatment for PCC DAVF and is predominantly performed through the internal jugular vein. Herein, we report a case of PCC DAVF treated with TVE through the deep cervical vein. This is the first case report of a PCC DAVF treated with TVE through the deep cervical vein.

Brainstem Infarctions Caused by a Proximal Marker of the PulseRider Device Obstructing the Origin of a Perforator.

The PulseRider (Cerenovus, Johnson & Johnson Medical Devices, New Brunswick, NJ, USA) is a neck reconstruction device that is used for the treatment of unruptured wide-necked bifurcation aneurysms. Herein, we describe the case of a 51-year-old male patient with a basilar apex aneurysm who was treated with PulseRider but had post-procedural brainstem infarctions caused by one of the proximal markers covering the origin of a perforator. In such cases, repositioning of the PulseRider should be performed to avoid infarctions.

The impact of the approval of prothrombin complex concentrates for vitamin K antagonist-related intracerebral hemorrhage: A retrospective study.

OBJECTIVES: This study aimed to determine the impact of the approval of prothrombin complex concentrates on the treatment of vitamin K antagonist-related intracerebral hemorrhage. MATERIALS AND METHODS: We retrospectively studied all patients with vitamin K antagonist-related intracerebral hemorrhage treated with prothrombin complex concentrate at our institutes between January 2010 and June 2021. Before approval, prothrombin complex concentrate was administered as either 500 or 1000 IU at the physician's discretion (previous dose group). After approval, we adopted the manufacturer's recommended regimen (recommended dose group). The primary outcome was post-administration international normalized ratio. Secondary outcomes were the amount of prothrombin complex concentrate administered and proportion of post-administration international normalized ratio <1.5, hematoma expansion, thrombotic events within 30 days, modified Rankin scale 0-3 at discharge, and in-hospital mortality. RESULTS: Thirty-two and 19 patients in the previous and recommended dose groups, respectively, were included. The post-administration international normalized ratio significantly differed between groups. The prothrombin complex concentrate dose and proportion of patients achieving post-administration international normalized ratio <1.5 were significantly higher in the recommended dose group than in the previous dose group (1500 IU vs. 500 IU, p<0.001 and 100% vs. 68%, p = 0.008). The proportions of hematoma expansion, thromboembolic events, modified Rankin scale 0-3, and mortality did not differ between groups. CONCLUSION: After prothrombin complex concentrate approval, prothrombin time-international normalized ratio correction was more effective with a significant increase in the prothrombin complex concentrates dose for vitamin K antagonist-associated intracerebral hemorrhage; however, there was no apparent difference in clinical outcomes.

Does difference in stem design affect accuracy of stem alignment in total hip arthroplasty with a CT-based navigation system?

The efficacy of a computed tomography (CT)-based navigation system to accurately position the stem for intended alignment is unclear. In addition, the influence of stem design on the accuracy of insertion is unknown. We therefore retrospectively compared the accuracy and precision for the intended alignment of two different designs of femoral stem which were implanted with or without the navigation system. Forty-nine total hip arthroplasties (THAs) using a tapered wedge stem and 91 THAs using an anatomic stem were evaluated for the navigation group. Thirty-three THAs using the tapered wedge stem and 15 THAs using the anatomic stem were controls for the non-navigation group. Differences between postoperative measurement and preoperative planning were compared among the groups. In the navigation groups, accuracy (mean absolute difference) and precision (95% limits of agreement) of stem anteversion were 4.3° and ± 10.1° in the tapered wedge stem and 3.1° and ± 6.9° in the anatomic stem. In the non-navigation groups, these were 6.0° and ± 15.2° and 4.8° and ± 12.4°, respectively. The accuracy and precision in the navigation groups were significantly superior to those in the non-navigation group, and those in the anatomic stem group were significantly superior to those in the tapered wedge group. Using the CT-based navigation system, the accuracy and precision for intended stem anteversion were improved. When compared under guidance of navigation system, the accuracy and precision for intended stem anteversion in the anatomic stem were superior to those in the tapered wedge stem.

Cortical Blood Flow Insufficiency Scores with Computed Tomography Perfusion can Predict Outcomes in Aneurysmal Subarachnoid Hemorrhage Patients: A Cohort Study.

BACKGROUND: The World Federation of Neurosurgical Societies (WFNS) scale is widely accepted for predicting outcomes for subarachnoid hemorrhage (SAH) patients. However, it is difficult to definitely predict outcomes for the most poor grade, WFNS grade 5. The present study aimed to investigate the prognostic ability of a novel classification using computed tomography perfusion (CTP) findings, called the cortical blood flow insufficiency (CBFI) scores. METHODS: CTP was performed on admission for aneurysmal SAH followed by radical treatments within 72 hours of onset. Twenty-four cerebral cortex regions of interest (ROIs) were defined. CBFI was defined as Tmax > 4 s in each ROI, and CBFI scores were calculated based on the total number of ROIs with CBFI. Using the optimal cutoff value based on receiver operating characteristics (ROC) analysis to predict patient functional outcomes, CBFI scores were divided into "high" or "low" CBFI scores. Patient functional outcomes at 90 days were categorized based on modified Rankin Scale scores (0-3, favorable group; 4-6 unfavorable group) (0-4, non-catastrophic group; 5-6, catastrophic group). RESULTS: Fifty-seven patients were included in this study, of whom 21 (36.8%) and 13 (22.8%) were in the unfavorable and the catastrophic groups, respectively. A factor predicting unfavorable and catastrophic outcomes was CBFI score cutoff value of 7 points (area under the curve, 0.73 and 0.81, respectively). In multivariable logistic regression analysis for unfavorable outcome, high CBFI scores (odds ratio (OR), 8.6; 95% confidence interval (CI), 1.1-65.4; P = 0.04) and WFNS grade 5 (OR, 30.0; 95% CI, 4.5-201.0; P < 0.001) remained as independent predictors, while for catastrophic outcome, high CBFI scores (OR, 25.3; 95% CI, 3.3-194.0; P = 0.002) and age (OR, 1.1; 95% CI, 1.0-1.2; P = 0.02) remained as independent predictors. Conversely, WFNS grade 5 was not an independent predictor of catastrophic outcomes (OR, 3.8; 95% CI, 0.6-24.0; P = 0.15). In high CBFI scores, the OR of the delayed cerebral ischemia (DCI) occurrence was 9.6 (95% CI, 1.5-61.4; P = 0.02) after adjusting for age. CONCLUSION: High CBFI scores could predict unfavorable and catastrophic outcomes for aneurysmal SAH patients and DCI occurrence.

Deep Learning-Derived High-Level Neuroimaging Features Predict Clinical Outcomes for Large Vessel Occlusion.

Background and Purpose- For patients with large vessel occlusion, neuroimaging biomarkers that evaluate the changes in brain tissue are important for determining the indications for mechanical thrombectomy. In this study, we applied deep learning to derive imaging features from pretreatment diffusion-weighted image data and evaluated the ability of these features in predicting clinical outcomes for patients with large vessel occlusion. Methods- This multicenter retrospective study included patients with anterior circulation large vessel occlusion treated with mechanical thrombectomy between 2013 and 2018. We designed a 2-output deep learning model based on convolutional neural networks (the convolutional neural network model). This model employed encoder-decoder architecture for the ischemic lesion segmentation, which automatically extracted high-level feature maps in its middle layers, and used its information to predict the clinical outcome. Its performance was internally validated with 5-fold cross-validation, externally validated, and the results compared with those from the standard neuroimaging biomarkers Alberta Stroke Program Early CT Score and ischemic core volume. The prediction target was a good clinical outcome, defined as a modified Rankin Scale score at 90-day follow-up of 0 to 2. Results- The derivation cohort included 250 patients, and the validation cohort included 74 patients. The convolutional neural network model showed the highest area under the receiver operating characteristic curve: 0.81±0.06 compared with 0.63±0.05 and 0.64±0.05 for the Alberta Stroke Program Early CT Score and ischemic core volume models, respectively. In the external validation, the area under the curve for the convolutional neural network model was significantly superior to those for the other 2 models. Conclusions- Compared with the standard neuroimaging biomarkers, our deep learning model derived a greater amount of prognostic information from pretreatment neuroimaging data. Although a confirmatory prospective evaluation is needed, the high-level imaging features derived by deep learning may offer an effective prognostic imaging biomarker.

Predicting Clinical Outcomes of Large Vessel Occlusion Before Mechanical Thrombectomy Using Machine Learning.

Background and Purpose- The clinical course of acute ischemic stroke with large vessel occlusion (LVO) is a multifactorial process with various prognostic factors. We aimed to model this process with machine learning and predict the long-term clinical outcome of LVO before endovascular treatment and to compare our method with previously developed pretreatment scoring methods. Methods- The derivation cohort included 387 LVO patients, and the external validation cohort included 115 LVO patients with anterior circulation who were treated with mechanical thrombectomy. The statistical model with logistic regression without regularization and machine learning algorithms, such as regularized logistic regression, linear support vector machine, and random forest, were used to predict good clinical outcome (modified Rankin Scale score of 0-2 at 90 days) with standard and multiple pretreatment clinical variables. Five previously reported pretreatment scoring methods (the Pittsburgh Response to Endovascular Therapy score, the Stroke Prognostication Using Age and National Institutes of Health Stroke Scale index, the Totaled Health Risks in Vascular Events score, the Houston Intra-Arterial Therapy score, and the Houston Intra-Arterial Therapy 2 score) were compared with these models for the area under the receiver operating characteristic curve. Results- The area under the receiver operating characteristic curve of random forest, which was the worst among the machine learning algorithms, was significantly higher than those of the standard statistical model and the best model among the previously reported pretreatment scoring methods in the derivation (the area under the receiver operating characteristic curve were 0.85±0.07 for random forest, 0.78±0.08 for logistic regression without regularization, and 0.77±0.09 for Stroke Prognostication using Age and National Institutes of Health Stroke Scale) and validation cohorts (the area under the receiver operating characteristic curve were 0.87±0.01 for random forest, 0.56±0.07 for logistic regression without regularization, and 0.83±0.00 for Pittsburgh Response to Endovascular Therapy). Conclusions- Machine learning methods with multiple pretreatment clinical variables can predict clinical outcomes of patients with anterior circulation LVO who undergo mechanical thrombectomy more accurately than previously developed pretreatment scoring methods.

Vagal Nerve Palsy After Transarterial Embolization of Transverse-Sigmoid Dural Arteriovenous Fistula Using Onyx.

OBJECTIVE: We report a case of a 70-year-old man who developed a transverse-sigmoid dural arteriovenous fistula (TS-DAVF) that was successfully treated by transarterial embolization (TAE) with Onyx. CASE PRESENTATION: The patient presented with sudden and progressive disturbance of consciousness and left hemiparesis. Magnetic resonance imaging (MRI) revealed venous infarction and hemorrhagic changes with brain swelling in the right parietal lobe. Angiography revealed a right TS-DAVF and multiple occlusions with retrograde leptomeningeal venous drainage into the cortical veins. The TS-DAVF was graded as Borden type III and Cognard type IIa+b. Because of its progressive clinical nature and wide distribution of DAVF in the occluded sinus wall, he underwent emergent TAE with liquid embolic materials including n-butyl cyanoacrylate and Onyx under informed consent by his family. Complete obliteration of the TS-DAVF was achieved, leading to a marked amelioration of symptoms, and MRI after treatment confirmed a decrease in the brain swelling. However, he suffered transient dysphagia due to right vagal nerve palsy caused by occlusion of vasa nervorum of ascending pharyngeal artery. He returned home 5 months later with a modified Rankin Scale of 1. CONCLUSIONS: TAE with Onyx appears to be effective for aggressive TS-DAVF with a widely distributed shunt. However, the blood supply to the cranial nerves and potentially dangerous anastomoses between the external-internal carotid artery and vertebral artery should be taken into account to avoid serious complications.

Does Robotic Milling For Stem Implantation in Cementless THA Result in Improved Outcomes Scores or Survivorship Compared with Hand Rasping? Results of a Randomized Trial at 10 Years.

BACKGROUND: Robotic-assisted THA has been promoted as potentially advantageous due to the precision it may afford when machining the proximal femur. However, few reports have compared the long-term clinical results of robotic techniques for femoral component insertion during THA regarding clinical outcomes scores or loosening. QUESTIONS/PURPOSES: The purpose of this study was to compare results from a randomized clinical trial (RCT) at a minimum followup of 10 years between robot-assisted and hand-rasped stem implantation techniques with regard to (1) Japanese Orthopaedic Association (JOA) clinical outcomes scores, and (2) aseptic loosening, revision surgery, and heterotopic ossification. METHODS: This is a concise followup of a previously reported RCT. In that trial, robot-assisted primary THA was performed on 75 hips (69 patients), and a hand-rasping technique was used on 71 hips (61 patients). Five experienced surgeons at two institutions participated in this trial; all THAs were performed through the posterolateral approach and the patients were treated similarly apart from the method used to prepare the femur. In all, 115 of 130 (88%) of patients initially randomized were available for followup at a minimum of 10 years (mean, 135 months; range, 120-152 months). There was no differential loss to followup between the study groups, and the final study groups here included 64 hips in 59 patients in the robotic group, and 64 hips in 56 patients in the hand-milling group. There were no differences between the study groups in terms of age, sex, diagnosis, body-mass index, or baseline JOA scores. The primary study endpoint was the JOA score, which is scored from 0 to 100, with higher scores representing better function and less pain. Secondary outcomes were revision surgery, and radiographic signs of aseptic loosening and heterotopic ossification as assessed using the four-grade Brooker scale by individuals other than the operating surgeon. RESULTS: At a minimum of 10 years postoperatively, there were no differences between patients treated with robot-assisted surgery or hand rasping in JOA scores (97 ± 5 versus 96 ± 7, mean difference 1.4; p = 0.159). No stems in either group developed aseptic loosening, and there were no revisions in either group. There was no difference between the groups in heterotopic ossification (19 of 64 [30%] in the robot-assisted group versus 12 of 64 [19%] in the hand-rasping group; p = 0.186), severe heterotopic ossification was uncommon in both groups, and no hips developed Grade 4 heterotopic ossification in either group. CONCLUSIONS: Clinically and radiographically, THAs performed with robotic milling for stem implantation did not result in better 10-year clinical outcomes scores, or a lower risk of loosening or revision, compared with hand-rasping. We recommend against widespread adoption of robotic milling for stem implantation in primary cementless THAs. LEVEL OF EVIDENCE: Level II, therapeutic study.

Effect of improved navigation performance on the accuracy of implant placement in total hip arthroplasty with a CT-based navigation system.

A computed tomography (CT)-based navigation system is one of the support tools to place implant with appropriate alignment and position in total hip arthroplasty (THA). To determine whether the higher performance of the navigation would further improve the accuracy of implant placement in the clinical setting, we retrospectively compared the navigation accuracy of two different versions of a navigation system. The newer version of the navigation system had an upgraded optical sensor with superior positional accuracy. Navigation accuracy, defined as differences between postoperative measurements on CT images and intraoperative records on the navigation system, of 49 THAs performed with the newer version of the navigation system was compared with that of 49 THAs performed with the older version. With the newer version, the mean absolute accuracy (95% limits of agreement) of implant alignment was 1.2° (± 3.3°) for cup inclination, 1.0° (± 2.4°) for cup anteversion, 2.0° (± 4.9°) for stem anteversion, and 1.1° (± 2.4°) for stem valgus angle. The accuracy of the implant position was 1.5 mm (± 3.1 mm), 1.3 mm (± 3.0 mm), and 1.5 mm (± 3.1 mm) for cup x-, y-, and z-axes, respectively, 1.6 mm (± 3.2 mm), 1.4 mm (± 2.9 mm), and 1.5 mm (± 2.7 mm) for stem x-, y-, and z-axes, respectively, and 2.4 mm (± 4.5 mm) for leg length discrepancy. The values for the newer version were significantly more accurate with less variation compared to those of the older version. With upgraded navigation performance, more accurate implant placement was demonstrated in the clinical setting.

Role of PKA signaling in D2 receptor-expressing neurons in the core of the nucleus accumbens in aversive learning.

The nucleus accumbens (NAc) serves as a key neural substrate for aversive learning and consists of two distinct subpopulations of medium-sized spiny neurons (MSNs). The MSNs of the direct pathway (dMSNs) and the indirect pathway (iMSNs) predominantly express dopamine (DA) D1 and D2 receptors, respectively, and are positively and negatively modulated by DA transmitters via Gs- and Gi-coupled cAMP-dependent protein kinase A (PKA) signaling cascades, respectively. In this investigation, we addressed how intracellular PKA signaling is involved in aversive learning in a cell type-specific manner. When the transmission of either dMSNs or iMSNs was unilaterally blocked by pathway-specific expression of transmission-blocking tetanus toxin, infusion of PKA inhibitors into the intact side of the NAc core abolished passive avoidance learning toward an electric shock in the indirect pathway-blocked mice, but not in the direct pathway-blocked mice. We then examined temporal changes in PKA activity in dMSNs and iMSNs in behaving mice by monitoring Förster resonance energy transfer responses of the PKA biosensor with the aid of microendoscopy. PKA activity was increased in iMSNs and decreased in dMSNs in both aversive memory formation and retrieval. Importantly, the increased PKA activity in iMSNs disappeared when aversive memory was prevented by keeping mice in the conditioning apparatus. Furthermore, the increase in PKA activity in iMSNs by aversive stimuli reflected facilitation of aversive memory retention. These results indicate that PKA signaling in iMSNs plays a critical role in both aversive memory formation and retention.