Studying tourism development and its impact on carbon emissions.

Analyzing the influence of tourism on carbon emission has significant implications for promoting the sustainable development of tourism. Based on the panel data of 31 tourist cities in China from 2005 to 2022, this study utilizes a structural equation model to explore the carbon reduction effect of tourism development and its influencing mechanism. The results show that: (1) The overall carbon emission efficiency of tourism cities first decreased and then increased, rised to a peak of 0.923 in 2022. (2) Tourism development has a significant positive impact on carbon emission efficiency, and there are three influence paths: tourism → environmental regulation → carbon emission efficiency, tourism → environmental regulation → industrial structure → carbon emission efficiency, and tourism → industrial structure → carbon emission efficiency. (3) The influence of tourism development on carbon emission efficiency mainly depends on the direct effect, and the development of tourism also indirectly affect the industrial structure. Environmental regulation also mainly depends on the direct effect on carbon emission efficiency. (4) Foreign direct investment lead to the reduction of carbon emission efficiency in both direct and indirect aspects.

Icariin mitigates anxiety-like behaviors induced by hemorrhagic shock and resuscitation via inhibiting of astrocytic activation.

BACKGROUND: Abnormal activation of astrocytes in the amygdala contributes to anxiety after hemorrhagic shock and resuscitation (HSR). Nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB)-associated epigenetic reprogramming of astrocytic activation is crucial to anxiety. A bioactive monomer derived from Epimedium icariin (ICA) has been reported to modulate NF-κB signaling and astrocytic activation. PURPOSE: The present study aimed to investigate the effects of ICA on post-HSR anxiety disorders and its potential mechanism of action. METHODS: We first induced HSR in mice through a bleeding and re-transfusion model and selectively inhibited and activated astrocytes in the amygdala using chemogenetics. Then, ICA (40 mg/kg) was administered by oral gavage once daily for 21 days. Behavioral, electrophysiological, and pathological changes were assessed after HSR using the light-dark transition test, elevated plus maze, recording of local field potential (LFP), and immunofluorescence assays. RESULTS: Exposure to HSR reduced the duration of the light chamber and attenuated open-arm entries. Moreover, HSR exposure increased the theta oscillation power in the amygdala and upregulated NF-κB p65, H3K27ac, and H3K4me3 expression. Contrarily, chemogenetic inhibition of astrocytes significantly reversed these changes. Chemogenetic inhibition in astrocytes was simulated by ICA, but chemogenetic activation of astrocytes blocked the neuroprotective effects of ICA. CONCLUSION: ICA mitigated anxiety-like behaviors induced by HSR in mice via inhibiting astrocytic activation, which is possibly associated with NF-κB-induced epigenetic reprogramming.

Dialysis disequilibrium syndrome in neurosurgery: literature review and illustrative case example.

INTRODUCTION: The dialysis disequilibrium syndrome (DDS) is a complication in those undergoing dialysis for chronic kidney disease (CKD) or acute kidney injury (AKI), characterized by nonspecific symptoms that may progress to coma and death secondary to cerebral edema. This syndrome is associated with rapid change in electrolytes during dialysis with changes in intracranial pressure (ICP) and may have a higher incidence in the elderly neurosurgical patient population. METHODS: Literature review and illustrative case example. RESULTS: A 62-year-old female presented with acute mental status change during hemodialysis (HD), with a history of a nonsurgical acute subdural hematoma (SDH) 10 days prior. Imaging showed a conversion of the acute SDH to chronic SDH of 12.2 mm in size with a 14.1 midline shift, for which she underwent a hemicraniectomy with SDH evacuation, with a gradual return to baseline. The literature review identified 5 publications meeting the inclusion criteria. Major theories of DDS include a reverse urea effect, intracerebral acidosis, idiogenic osmoles, and local inflammation. This complication may occur more frequently in the elderly neurosurgical patient population, likely due to age-related comorbidities, preexisting neurological insult, and increased permeability of the blood-brain barrier (BBB), leading to cerebral edema. CONCLUSION: DDS is a rare and potentially fatal complication of HD that may have a higher incidence in the elderly neurosurgical patient population, yet remains to be fully understood. Further study is recommended to characterize the pathophysiological mechanism and incidence of DDS in neurosurgical patients.

Arteriovenous malformation with unique drainage through the emissary vein of the foramen ovale: illustrative case.

BACKGROUND: As part of the laterotrigeminal venous system (LTVS), the emissary vein of the foramen ovale (EVFO) is an underrecognized venous structure communicating between the cavernous sinus and pterygoid plexus. The sphenobasal sinus is an anatomical variation of the sphenoparietal sinus that drains directly into the EVFO. The authors present the case of a ruptured arteriovenous malformation (AVM) with a unique drainage pattern through the sphenobasal sinus and EVFO. OBSERVATIONS: A 9-year-old female initially presented with loss of consciousness and was subsequently found to have a ruptured AVM in the left basal frontal area. She underwent an immediate decompressive hemicraniectomy, with a computed tomography angiogram demonstrating a unique anatomical variation in which the sphenobasal sinus communicated with the EVFO and LTVS. The final venous drainage returned to the pterygoid plexus and external jugular vein. Postoperatively, the patient made a substantial recovery, with generalized right-sided weakness remaining as the sole deficit. LESSONS: The authors present the case of a ruptured AVM with unique venous drainage into the sphenobasal sinus and EVFO, for which the current literature remains limited. As exemplified by this illustrative case, technique modification may be warranted in the setting of this unique anatomical variation to avoid venous sinus injury.

An institutional experience in applying quality improvement measures to pituitary surgery: clinical and resource implications.

OBJECTIVE: The aim of this study was to report the authors' experience developing a Lean Six Sigma clinical care pathway (CCP) for endoscopic endonasal transsphenoidal operations. METHODS: Using Lean Six Sigma quality improvement principles-including the define, measure, analyze, improve, and control framework-the authors developed a CCP for endoscopic endonasal transsphenoidal operations, incorporating preoperative, intraoperative, and inpatient and outpatient postoperative phases of care. Efficacy and quality metrics were defined as postoperative length of stay (LOS), presentation to the emergency department (ED) or readmission within 30 days of discharge, and hospital charges. The study included all adult patients who underwent elective endoscopic endonasal resection for pituitary adenoma, Rathke's cleft cyst, craniopharyngioma, pituicytoma, or arachnoid cyst during the sampling period (April 1, 2018, to December 31, 2022). RESULTS: Two hundred twenty-eight patients met criteria and were included; 94 were treated before and 134 were treated after implementation of the CCP. Differences between groups in age, gender, race, BMI, American Society of Anesthesiologists classification, geographic distribution, preoperative serum sodium, tumor size, adenoma functional status, and prior surgery were not significant. The mean postoperative LOS significantly decreased from 4.5 to 1.7 days following CCP implementation (p < 0.0001); LOS variability also decreased, with the standard deviation declining from 3.1 to 1.5 days. The proportion of patients discharged on postoperative day (POD) 1 significantly increased from 0% to 61.9% (p < 0.0001). Fewer than one-quarter of the patients (23.4%) were discharged by POD 2 prior to the CCP, while 88.8% of were discharged by POD 2 after CCP implementation (p < 0.0001). Rates of 30-day ED presentations or readmissions were not significantly different (2.1% vs 6.0%, p = 0.20, and 7.5% vs 6.7%, p > 0.99, respectively). Mean per-patient hospital costs declined from $38,326 to $26,289 (p < 0.0001), with an associated change in cost variability from a standard deviation of $16,716 to $12,498. CONCLUSIONS: CCP implementation significantly improved LOS and costs of endoscopic endonasal resection, without adversely impacting postoperative ED presentations or readmissions.

Threshold effect of technological innovation on carbon emission intensity based on multi-source heterogeneous data.

It is of much importance to clarify the impact of technological innovation on carbon emission intensity for the low-carbon transformation of China's economy. This study, based on the panel data of 30 Chinese provinces and municipalities from 2010 to 2020, measures and analyzes the carbon emission intensity and the level of technological innovation, establishing a spatial econometric model to study the spatial spillover effect and a panel threshold model to analyze the nonlinear influence of technological innovation level on carbon emission intensity. The findings are as follows: First, the overall carbon emission intensity in China shows a decreasing trend from 2010 to 2020, with the average dropping from 3.09 in 2010 to 1.98 in 2020; Second, the spatial autocorrelation results reveal that the level of technological innovation and carbon emission intensity in China are obviously aggregated in the global spatial distribution pattern. Third, the regression results of the spatial econometric model show that the direct effect of technological innovation on carbon emission intensity is significantly negative at the level of 1%, that is, the improvement of the technological innovation in a certain area has a significant inhibitory effect on carbon emission intensity. Fourth, based on the level of economic development, there is a significant three-threshold effect of the level of technological innovation on carbon emission intensity in China, and the influence of the level of technological innovation on carbon emission intensity varies in the direction of existence and coefficient values within different threshold intervals. As economic development reaches the third interval, the technological innovation level has the most significant inhibition on carbon emission intensity. These findings enriches the research of the nonlinear relationship between technological innovation and carbon emission intensity, clarifies the spatial spillover effect and threshold effect between among them, and provides inspiration for better promote the low-carbon transformation of economy.

Spatial and temporal evolution of urban carbon emission efficiency in China.

Improving carbon emission efficiency is crucial for achieving carbon peak and carbon neutrality. This paper analyzes the carbon emission efficiency of Chinese cities using panel data from 275 prefecture-level cities between 2006 and 2020. The super-efficiency SBM (undesirable slacks-based measurement) model of undesired output, combined with kernel density estimation and exploratory data analysis, is employed. This study finds, firstly, from 2006 to 2020, the average efficiency of carbon emissions in Chinese cities declined from 0.53 to 0.48, indicating a downward trend. Secondly, from a temporal perspective, the level of dispersion in urban carbon emission efficiency has become increasingly distinct over time, coupled with a decrease in polarization. Thirdly, in terms of spatial analysis, urban carbon emission efficiency in China shows a positive correlation in a global context. In terms of local spatial correlation, it primarily exhibits high-high and low-low clusters, with a few instances of low-high and high-low clusters. Finally, based on the research findings, this paper proposes suggestions to improve urban carbon emission efficiency.

Regional common prosperity level and its spatial relationship with carbon emission intensity in China.

The characteristics of common prosperity include harmonious relationships between humans and the environment, as well as sustainable economic and social growth. The process of achieving common prosperity will necessarily have an impact on carbon emissions. In this article, panel statistics collected from 30 Chinese provinces and cities between the years 2006 and 2020 are utilized to assess the level of common prosperity and the intensity of carbon emissions in China. Then the SDM model is applied to explore the effects of the common prosperity level on the intensity of carbon emissions. The findings reveal that: (i) The common prosperity level in China has shown an increasing tendency. Between 2006 and 2020, the mean level of common prosperity increased from 0.254 to 0.486. From the regional perspective, eastern China has seen greater levels of common prosperity than central China, while central China has experienced greater levels of common prosperity than western China; regional disparities in the degree of common prosperity are substantial among Chinese provinces from 2006 to 2020; the common prosperity level is relatively high in economically developed provinces and relatively low in economically backward provinces. (ii) China's carbon emission intensity shows a continuous downward tendency. The annual average intensity of China's carbon emissions decreased from 4.458 in 2006 to 2.234 in 2020. From the regional perspective, the three main regions' carbon emission intensity likewise exhibits a decline in tendency between 2006 and 2020; still, western China continues to have the greatest carbon emission intensity, following central China, while eastern China has the smallest; however, certain provinces, notably Inner Mongolia and Shanxi, continue to have high carbon emission intensity. (iii) China's common prosperity level and carbon emission intensity both exhibit positive spatial autocorrelation at a 1% significant level under the adjacency matrix. The spatial agglomeration effect is significant, and adjacent provinces can affect each other. (iv) The SDM (Spatial Durbin Model) model test with fixed effects finds that the increase in the level of common prosperity suppresses the intensity of carbon emissions in the local area and neighboring regions. (v) The mediating effects model indicates that the process of common prosperity suppresses carbon emission intensity through high-quality economic development, narrowing the income disparity, and the development of a sharing economy.

Bilateral cerebellopontine angle lipomas in an infant with encephalocele: illustrative case.

BACKGROUND: Bilateral cerebellopontine angle (CPA) lipomas are extremely rare. Herein the authors present a case of bilateral CPA lipomas in an infant along with a literature review of bilateral CPA lipomas. OBSERVATIONS: A newborn girl was incidentally found to have bilateral CPA lipomas during the workup for an occipital encephalocele. The encephalocele was repaired primarily on day 2 after birth. The patient demonstrated no symptoms associated with the bilateral CPA lipomas. Eight cases of bilateral CPA lipomas were identified in the literature review and are summarized. Conservative management is the consensus strategy, given minimum growth of the tumor and the high risk of surgical intervention. LESSONS: This is the first reported case of bilateral CPA lipomas in an infant as well as the first with a coexisting intracranial malformation. Intracranial lipomas share an extremely low growth rate and typically do not cause severe symptoms. The management of asymptomatic or mildly symptomatic bilateral CPA lipomas is usually conservative.

An endolysin gene from Candidatus Liberibacter asiaticus confers dual resistance to huanglongbing and citrus canker.

The most damaging citrus diseases are Huanglongbing (HLB) and citrus canker, which are caused by Candidatus Liberibacter asiaticus (CaLas) and Xanthomonas citri pv. citri (Xcc), respectively. Endolysins from bacteriophages are a possible option for disease resistance in plant breeding. Here, we report improvement of citrus resistance to HLB and citrus canker using the LasLYS1 and LasLYS2 endolysins from CaLas. LasLYS2 demonstrated bactericidal efficacy against several Rhizobiaceae bacteria and Xcc, according to inhibition zone analyses. The two genes, driven by a strong promoter from Cauliflower mosaic virus, 35S, were integrated into Carrizo citrange via Agrobacterium-mediated transformation. More than 2 years of greenhouse testing indicated that LasLYS2 provided substantial and long-lasting resistance to HLB, allowing transgenic plants to retain low CaLas titers and no obvious symptoms while also clearing CaLas from infected plants in the long term. LasLYS2 transgenic plants with improved HLB resistance also showed resistance to Xcc, indicating that LasLYS2 had dual resistance to HLB and citrus canker. A microbiome study of transgenic plants revealed that the endolysins repressed Xanthomonadaceae and Rhizobiaceae populations in roots while increasing Burkholderiaceae and Rhodanobacteraceae populations, which might boost the citrus defense response, according to transcriptome analysis. We also found that Lyz domain 2 is the key bactericidal motif of LasLYS1 and LasLYS2. Four endolysins with potential resistance to HLB and citrus canker were found based on the structures of LasLYS1 and LasLYS2. Overall, the work shed light on the mechanisms of resistance of CaLas-derived endolysins, providing insights for designing endolysins to develop broad-spectrum disease resistance in citrus.

Aspirator-Assisted Endoscopic Third Ventriculostomy in an Infant: 2-Dimensional Operative Video.

Endoscopic third ventriculostomy (ETV) is an effective treatment for hydrocephalus in carefully selected patients.1 Studies have shown that larger ostomy size may be associated with higher ETV success and reduced ostomy closure in pediatric and adult patients.2-5 Therefore dilation of the ostomy is a key step in this procedure, which is traditionally accomplished with a balloon catheter, leaving behind loose redundant tissue at the ostomy site. In this 2-dimensional endoscopic operation (Video 1), we demonstrate the technique of using an aspiration device to enlarge the ETV ostomy in a controlled and efficient manner while eliminating redundant tissue. The patient is a 6-month-old girl with newly developed triventricular hydrocephalus seen on head ultrasound, manifested as upward gaze palsy, fontanelle fullness, and rapidly increasing head circumference. We chose to treat her with an ETV, given an ETV success score of 70.6,7 She underwent an ETV augmented with the NICO Myriad aspirator (NICO Corporation, Indianapolis, Indiana, USA) and achieved excellent clinical outcome. No intraoperative or postoperative complication occurred. Postoperative magnetic resonance imaging demonstrated an 8.4-mm ostomy on the third ventricular floor, nearly twice the size of a typical ETV ostomy.5 The key considerations in using this device include setting a low aspiration limit to avoid oversuction and using only mediolateral motion to avoid damage to the basilar artery. Future comparative studies are needed to investigate the efficacy, safety, and long-term outcome in aspirator-assisted ETV versus traditional techniques, as well as to evaluate ostomy size as an independent variable for long-term ETV success.

CcRR5 interacts with CcRR14 and CcSnRK2s to regulate the root development in citrus.

Response regulator (RR) is an important component of the cytokinin (CK) signal transduction system associated with root development and stress resistance in model plants. However, the function of RR gene and the molecular mechanism on regulating the root development in woody plants such as citrus remain unclear. Here, we demonstrate that CcRR5, a member of the type A RR, regulates the morphogenesis of root through interacting with CcRR14 and CcSnRK2s in citrus. CcRR5 is mainly expressed in root tips and young leaves. The activity of CcRR5 promoter triggered by CcRR14 was proved with transient expression assay. Seven SnRK2 family members with highly conserved domains were identified in citrus. Among them, CcSnRK2.3, CcSnRK2.6, CcSnRK2.7, and CcSnRK2.8 can interact with CcRR5 and CcRR14. Phenotypic analysis of CcRR5 overexpressed transgenic citrus plants indicated that the transcription level of CcRR5 was associated with root length and lateral root numbers. This was also correlated to the expression of root-related genes and thus confirmed that CcRR5 is involved in the root development. Taken together, the results of this study indicate that CcRR5 is a positive regulator of root growth and CcRR14 directly regulates the expression of CcRR5. Both CcRR5 and CcRR14 can interact with CcSnRK2s.

Open Surgical Approaches for Meningiomas.

Meningiomas are the most common intracranial extra-axial primary tumor. Although most are low grade and slow growing, resection can be technically challenging, particularly when located at the skull base. Appropriate craniotomy and approach selection are of paramount importance to minimize brain retraction, optimize exposure, and achieve complete resection. This article summarizes various craniotomies and their approaches to meningiomas, and illustrates some nuances in performing these techniques with cadaveric dissection and operative videos.

Novel retro-auricular myocutaneous hemicraniectomy flap: Technical note and cadaveric dissection.

Objective: The hemicraniectomy is a common technique used in a variety of pathologies including some traumatic brain injury and malignant stroke. A novel technique of performing hemicraniectomies using a retro-auricular incision can avoid transgressing the temporalis muscle and superficial temporal artery while providing adequate hemicranial exposure. Methods: This technique was reproduced in a skull base lab using a cadaveric head. The key steps of this approach were illustrated in step-by-step fashion. A post-approach CT scan of the cadaver was performed to evaluate the decompression exposure. Results: This approach can provide sufficient middle fossa decompression and area of exposure, while preserving the temporalis along with the superficial temporal artery. A step-by-step technical illustration is demonstrated in the present note. Conclusions: The modified retro-auricular myocutaneous flap is a novel technique in hemicraniectomy which can provide sufficient middle fossa decompression and exposure while sparing the temporalis muscle and superficial temporal artery during the approach.

Nervus intermedius: Microsurgical and anatomic relationships to the cerebellopontine angle neurovascular complex.

Background: The nervus intermedius (NI) comprises fibers originating from the trigeminal, superior salivary, and solitary tract nuclei, which join the facial nerve (cranial nerve [CN] VII). Neighboring structures include the vestibulocochlear nerve (CN VIII), the anterior inferior cerebellar artery (AICA), and its branches. Microsurgical procedures at the cerebellopontine angle (CPA) benefit from understanding NI anatomy and relationships, especially for the microsurgical treatment of geniculate neuralgia, where the NI is transected. This study sought to characterize common relationships between the NI rootlets, CN VII, CN VIII, and the meatal loop of AICA at the internal auditory canal (IAC). Methods: Seventeen cadaveric heads underwent retrosigmoid craniectomy. Following complete unroofing of the IAC, the NI rootlets were individually exposed to identify their origins and insertion points. The AICA and its meatal loop were traced to assess their relationship with the NI rootlets. Results: Thirty-three NIs were identified. The median number of NI rootlets was 4 per NI (interquartile range, 3-5). The rootlets mainly originated from the proximal premeatal segment of CN VIII (81 of 141, 57%) and inserted onto CN VII at the IAC fundus (89 of 141, 63%). When crossing the acoustic-facial bundle, the AICA most frequently passed between the NI and CN VIII (14 of 33, 42%). Five composite patterns of neurovascular relationships were identified regarding NI. Conclusion: Although certain anatomical trends can be identified, the NI has a variable relationship with the adjacent neurovascular complex at the IAC. Therefore, anatomical relationships should not be used as the sole method of NI identification during CPA surgery.

Transfer of extensor carpi radialis brevis branch of radial nerve to anterior interosseous nerve for lower trunk brachial plexopathy after motor vehicle accident.

The patient is a 15-year-old male who sustained injury to his right lower brachial plexus (C8-T1) in a motor vehicle accident. Six months after the injury, the patient still had persistent hand weakness and wished to regain function in his first and second digits. Transfer of the extensor carpi radialis brevis (ECRB) branch of the radial nerve to the anterior interosseous nerve (AIN) was performed to restore motor function. The patient did well after the surgery, although it may take 12-24 months for benefits to fully manifest. Pertinent surgical anatomy and techniques are highlighted in this video demonstration. The video can be found here: https://stream.cadmore.media/rr10.3171/2022.10.FOCVID2287.

MiR-129-3p regulates ferroptosis in the liver of Selenium-deficient broilers by targeting SLC7A11.

Selenium (Se) has been proven to be an essential trace element for organism. Se deficiency in poultry can cause widespread damage, such as exudative diathesis. The liver is not only the main organ of metabolism, but also one of the organs with high Se content in organism. Recent studies have shown that solute carrier family 7 member 11 (SLC7A11) plays a key role in the negative regulation of ferroptosis. In order to explore the mechanism of Se deficiency induces liver ferroptosis in broilers, and the role of microRNAs (miRNAs) in this process, we divided broilers into 2 groups: control group (0.2 mg/kg Se) and Se deficiency group (0.03 mg/kg Se). Hematoxylin-Eosin staining detected liver tissue damage in broilers. Predicted and verified the targeting relationship between miR-129-3p and SLC7A11 through miRDB and dual luciferase report experiments. The genes related to ferroptosis were detected by qRT-PCR and Western Blot. The results showed that the expression level of miR-129-3p mRNA in Se-deficient liver was significantly increased. To understand whether the miR-129-3p/SLC7A11 axis could involve in the process of ferroptosis, our further research showed that overexpression of miR-129-3p could reduce the expression of SLC7A11 and its downstream GCL, GSS, and GPX4, thereby inducing ferroptosis. These data indicates that miR-129-3p affected ferroptosis under Se deficiency conditions through the SLC7A11 pathway. Our research provides a new perspective for the mechanism of Se deficiency on the liver damage.

The Effect of the Magnesium Sulfate in Ultrasound-Guided Quadratus Lumborum Block on Postoperative Analgesia: A Randomized Controlled Trial.

INTRODUCTION: Quadratus lumborum block (QLB) has proven to be an effective analgesic technique in various abdominal surgeries. Magnesium sulfate as an adjuvant in different nerve blocks has been reported. The aim of this study was to assess the efficacy of magnesium sulfate as an adjuvant to ropivacaine in an ultrasound-guided QLB for postoperative analgesia in laparoscopic gynecologic surgery. METHODS: Ninety patients belonging to American Society of Anesthesiologists (ASA) physical status I or II, aged between 40 and 60 years, scheduled for laparoscopic gynecologic surgery were enrolled. Patients were divided into three groups and received bilateral quadratus lumborum block: ropivacaine group (group N, 0.375% ropivacaine 40 ml + normal saline 4 ml), magnesium sulfate group (group M, 0.375% ropivacaine 40 ml + 10% magnesium sulfate 4 ml), and control group (group C, normal saline 44 ml). Visual analogue scale (VAS) at rest and during activity at 4, 6, 12, 24, and 48 h postoperatively, consumption of morphine, the time of first analgesic request, frequency of rescue analgesia, satisfaction with postoperative analgesia, and any side effects were recorded. RESULTS: VAS scores in groups M and N were significantly lower than in group C at 4 and 6 h postoperatively (P < 0.001). VAS scores were lower in group M at 12 and 24 h postoperatively compared to groups N and C (P < 0.05). The mean total morphine consumption was significantly lower in group M than in groups N and C (P < 0.001). The mean time to the first patient-controlled analgesia (PCA) bolus was significantly prolonged in group M compared to group C (P < 0.05). The satisfaction with postoperative analgesia of group M was superior to that of groups N and C (P < 0.05). There was no significant difference in side effects among the three groups. CONCLUSION: Magnesium sulfate as an adjuvant to ropivacaine in ultrasound-guided QLB prolongs the duration of analgesia, decreases analgesic requirements, and improves patient satisfaction without significant side effects. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR1900027066.

Seven bypasses simulation set: description and validity assessment of novel models for microneurosurgical training.

OBJECTIVE: Microsurgical training remains indispensable to master cerebrovascular bypass procedures, but simulation models for training that accurately replicate microanastomosis in narrow, deep-operating corridors are lacking. Seven simulation bypass scenarios were developed that included head models in various surgical positions with premade approaches, simulating the restrictions of the surgical corridors and hand positions for microvascular bypass training. This study describes these models and assesses their validity. METHODS: Simulation models were created using 3D printing of the skull with a designed craniotomy. Brain and external soft tissues were cast using a silicone molding technique from the clay-sculptured prototypes. The 7 simulation scenarios included: 1) temporal craniotomy for a superficial temporal artery (STA)-middle cerebral artery (MCA) bypass using the M4 branch of the MCA; 2) pterional craniotomy and transsylvian approach for STA-M2 bypass; 3) bifrontal craniotomy and interhemispheric approach for side-to-side bypass using the A3 branches of the anterior cerebral artery; 4) far lateral craniotomy and transcerebellomedullary approach for a posterior inferior cerebellar artery (PICA)-PICA bypass or 5) PICA reanastomosis; 6) orbitozygomatic craniotomy and transsylvian-subtemporal approach for a posterior cerebral artery bypass; and 7) extended retrosigmoid craniotomy and transcerebellopontine approach for an occipital artery-anterior inferior cerebellar artery bypass. Experienced neurosurgeons evaluated each model by practicing the aforementioned bypasses on the models. Face and content validities were assessed using the bypass participant survey. RESULTS: A workflow for model production was developed, and these models were used during microsurgical courses at 2 neurosurgical institutions. Each model is accompanied by a corresponding prototypical case and surgical video, creating a simulation scenario. Seven experienced cerebrovascular neurosurgeons practiced microvascular anastomoses on each of the models and completed surveys. They reported that actual anastomosis within a specific approach was well replicated by the models, and difficulty was comparable to that for real surgery, which confirms the face validity of the models. All experts stated that practice using these models may improve bypass technique, instrument handling, and surgical technique when applied to patients, confirming the content validity of the models. CONCLUSIONS: The 7 bypasses simulation set includes novel models that effectively simulate surgical scenarios of a bypass within distinct deep anatomical corridors, as well as hand and operator positions. These models use artificial materials, are reusable, and can be implemented for personal training and during microsurgical courses.