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1.
J Neurosurg Spine ; : 1-10, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38996394

RESUMO

OBJECTIVE: Second cervical vertebrae (C2) fractures are a common traumatic spinal injury in the elderly population. Surgical fusion and nonoperative bracing are two primary treatments for cervical instability, but the former is often withheld in the elderly due to concerns for poor postoperative outcomes arising from patient frailty. This study sought to evaluate the in-hospital differences in mortality, outcomes, and discharge disposition in elderly patients with C2 fractures undergoing surgical intervention compared with conservative therapy. METHODS: The National Trauma Data Bank was queried from 2017 to 2019 for all patients aged ≥ 65 years with C2 fractures undergoing either surgical stabilization or conservative therapy. Propensity score matching was performed using k-nearest neighbors with replacement based on patient demographics, comorbidities, insurance type, injury severity, and fracture type. Group differences were compared using Student t-tests and Pearson's chi-square tests with Benjamini-Hochberg multiple comparisons correction. Subgroup analyses were performed in the 65-74, 75-79, and 80+ year age subgroups. RESULTS: Six thousand forty-nine patients were identified, of whom 2156 underwent surgery and 3893 received conservative treatment. Following matching, the surgery group had significantly lower mortality rates (5.52% vs 9.6%, p < 0.001), a longer mean hospital length of stay (LOS; 12.64 vs 7.49 days p < 0.001), and slightly higher rates of several complications (< 3% difference), as well as lower rates of discharge home (14.56% vs 23.52%, p < 0.001) and to hospice (1.07% vs 2.09%, p = 0.02) and a higher rate of discharge to intermediate care (68.83% vs 48.28%, p < 0.001). Similar trends in mortality and LOS were noted in all 3 subgroups. CONCLUSIONS: In elderly patients with C2 fractures, surgical stabilization confers a small survival advantage with a slightly higher in-hospital complication rate compared to conservative therapy. The increased rate of discharge to rehabilitation may represent better long-term prognosis following surgery. The increased risk of short-term complications is present but relatively small, thus surgery should not be withheld in patients with good long-term prognosis.

2.
Asian Spine J ; 18(3): 362-371, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38779702

RESUMO

STUDY DESIGN: This was a retrospective case-control study using 8 years of data from a nationwide database of surgical outcomes in the United States. PURPOSE: This study aimed to improve our understanding of the risk factors associated with a length of stay (LOS) >1 day and aid in reducing postoperative hospitalization and complications. OVERVIEW OF LITERATURE: Despite the proven safety of transforaminal lumbar interbody fusion (TLIF), some patients face prolonged postoperative hospitalization. METHODS: Data were collected from the American College of Surgeons National Surgical Quality Improvement Program dataset from 2011 to 2018. The cohort was divided into patients with LOS up to 1 day (LOS ≤1 day), defined as same day or next-morning discharge, and patients with LOS >1 day (LOS >1 day). Univariable and multivariable regression analyses were performed to evaluate predictors of LOS >1 day. Propensity-score matching was performed to compare pre- and postdischarge complication rates. RESULTS: A total of 12,664 eligible patients with TLIF were identified, of which 14.8% had LOS ≤1 day and 85.2% had LOS >1 day. LOS >1 day was positively associated with female sex, Hispanic ethnicity, diagnosis of spondylolisthesis, American Society of Anesthesiologists classification 3, and operation length of >150 minutes. Patients with LOS >1 day were more likely to undergo intraoperative/postoperative blood transfusion (0.3% vs. 4.5%, p<0.001) and reoperation (0.1% vs. 0.6%, p=0.004). No significant differences in the rates of postdischarge complications were found between the matched groups. CONCLUSIONS: Patients with worsened preoperative status, preoperative diagnosis of spondylolisthesis, and prolonged operative time are more likely to require prolonged hospitalization and blood transfusions and undergo unplanned reoperation. To reduce the risk of prolonged hospitalization and associated complications, patients indicated for TLIF should be carefully selected.

3.
Sci Rep ; 14(1): 2446, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38291036

RESUMO

The multi polar fuzzy (m-PF) set has an extensive range of implementations in real world problems related to the multi-polar information, multi-index and multi-attributes data. This paper introduces innovative extensions to algebraic structures. We present the definitions and some important results of m-polar fuzzy subsemirings (m-PFSSs), m-polar fuzzy ideals (m-PFIs), m-polar fuzzy generalized bi-ideals (m-PFGBIs), m-polar fuzzy bi-ideals (m-PFBIs) and m-polar fuzzy quasi-ideals (m-PFQIs) in semirings. The main contributions of the paper include the derivation and proof of key theorems that shed light on the algebraic interplay and computational aspects of m-polar fuzzy ideals (m-PFIs), m-polar fuzzy generalized bi-ideals (m-PFGBIs), m-polar fuzzy bi-ideals (m-PFBIs) and m-polar fuzzy quasi-ideals (m-PFQIs) in semirings along with examples. Moreover, this paper deals with several important properties of m-PFIs and characterizes regular and intra-regular semirings by the properties of these ideals.

4.
World Neurosurg ; 184: e228-e236, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38266996

RESUMO

OBJECTIVE: Central cord syndrome (CCS) is a traumatic cervical spine injury that is treated with surgical decompression. In octogenarians (80-89), surgeons often opt for conservative management instead due to fears of postoperative complications and prolonged recovery times. This study aims to assess the in-hospital complications and outcomes in octogenarians undergoing surgery compared to those undergoing nonsurgical management for CCS. METHODS: The National Trauma Data Bank was queried from 2017 to 2019 for octogenarians with CCS. Patients who received surgical fusion or decompression were divided into the surgery group and the remaining into the nonsurgical group. The surgery group was sampled and propensity score matched with the non-surgery group. Student t tests and Pearson χ2 tests were used to test for group differences. RESULTS: A total of 759 octogenarians with CCS were identified. Following sampling and propensity score matching, 225 patients were identified in each group. The surgery group experienced longer intensive care unit (6.8 days vs. 3.21 days, P < 0.001) and hospital (13.79 days vs. 7.8 days, P < 0.001) lengths of stay and higher rates of deep vein thrombosis (4.89% vs. 0.44%, P = 0.02) and ventilator-associated pneumonia (4% vs. 0%, P = 0.02). Patients did not otherwise differ in mortality rate, other hospital complications, and discharge disposition. CONCLUSIONS: Octogenarians undergoing surgery for CCS experience longer length of stay and complications consistent with prolonged hospitalization but otherwise have similar mortality, hospital complications, and discharge disposition compared to non-surgical treatment. Given the relative lack of short-term drawbacks, surgery should be considered first-line management when the long-term benefits are substantive.


Assuntos
Síndrome Medular Central , Traumatismos da Coluna Vertebral , Idoso de 80 Anos ou mais , Humanos , Octogenários , Pontuação de Propensão , Complicações Pós-Operatórias/epidemiologia , Resultado do Tratamento , Estudos Retrospectivos , Tempo de Internação
5.
J Neurosurg Spine ; 40(4): 428-438, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38241683

RESUMO

OBJECTIVE: It is not clear whether there is an additive effect of social factors in keeping patients with cervical spondylotic myelopathy (CSM) from achieving both a minimum clinically important difference (MCID) in outcomes and satisfaction after surgery. The aim of this study was to explore the effect of multiple social factors on postoperative outcomes and satisfaction. METHODS: This was a multiinstitutional, retrospective study of the prospective Quality Outcomes Database (QOD) CSM cohort, which included patients aged 18 years or older who were diagnosed with primary CSM and underwent operative management. Social factors included race (White vs non-White), education (high school or below vs above), employment (employed vs not), and insurance (private vs nonprivate). Patients were considered to have improved from surgery if the following criteria were met: 1) they reported a score of 1 or 2 on the North American Spine Society index, and 2) they met the MCID in patient-reported outcomes (i.e., visual analog scale [VAS] neck and arm pain, Neck Disability Index [NDI], and EuroQol-5D [EQ-5D]). RESULTS: Of the 1141 patients included in the study, 205 (18.0%) had 0, 347 (30.4%) had 1, 334 (29.3%) had 2, and 255 (22.3%) had 3 social factors. The 24-month follow-up rate was > 80% for all patient-reported outcomes. After adjusting for all relevant covariates (p < 0.02), patients with 1 or more social factors were less likely to improve from surgery in all measured outcomes including VAS neck pain (OR 0.90, 95% CI 0.83-0.99) and arm pain (OR 0.88, 95% CI 0.80-0.96); NDI (OR 0.90, 95% CI 0.83-0.98); and EQ-5D (OR 0.90, 95% CI 0.83-0.97) (all p < 0.05) compared to those without any social factors. Patients with 2 social factors (outcomes: neck pain OR 0.86, arm pain OR 0.81, NDI OR 0.84, EQ-5D OR 0.81; all p < 0.05) or 3 social factors (outcomes: neck pain OR 0.84, arm pain OR 0.84, NDI OR 0.84, EQ-5D OR 0.84; all p < 0.05) were more likely to fare worse in all outcomes compared to those with only 1 social factor. CONCLUSIONS: Compared to those without any social factors, patients who had at least 1 social factor were less likely to achieve MCID and feel satisfied after surgery. The effect of social factors is additive in that patients with a higher number of factors are less likely to improve compared to those with only 1 social factor.


Assuntos
Cervicalgia , Doenças da Medula Espinal , Humanos , Cervicalgia/cirurgia , Resultado do Tratamento , Fatores Sociais , Satisfação do Paciente , Estudos Retrospectivos , Estudos Prospectivos , Vértebras Cervicais/cirurgia , Doenças da Medula Espinal/cirurgia , Medidas de Resultados Relatados pelo Paciente , Satisfação Pessoal
6.
J Neurosurg Spine ; 40(2): 206-215, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-37948703

RESUMO

OBJECTIVE: The aim of this study was to explore the preoperative patient characteristics that affect surgical decision-making when selecting an anterior or posterior operative approach in patients diagnosed with cervical spondylotic myelopathy (CSM). METHODS: This was a multi-institutional, retrospective study of the prospective Quality Outcomes Database (QOD) Cervical Spondylotic Myelopathy module. Patients aged 18 years or older diagnosed with primary CSM who underwent multilevel (≥ 2-level) elective surgery were included. Demographics and baseline clinical characteristics were collected. RESULTS: Of the 841 patients with CSM in the database, 492 (58.5%) underwent multilevel anterior surgery and 349 (41.5%) underwent multilevel posterior surgery. Surgeons more often performed a posterior surgical approach in older patients (mean 64.8 ± 10.6 vs 58.5 ± 11.1 years, p < 0.001) and those with a higher American Society of Anesthesiologists class (class III or IV: 52.4% vs 46.3%, p = 0.003), a higher rate of motor deficit (67.0% vs 58.7%, p = 0.014), worse myelopathy (mean modified Japanese Orthopaedic Association score 11.4 ± 3.1 vs 12.4 ± 2.6, p < 0.001), and more levels treated (4.3 ± 1.3 vs 2.4 ± 0.6, p < 0.001). On the other hand, surgeons more frequently performed an anterior surgical approach when patients were employed (47.2% vs 23.2%, p < 0.001) and had intervertebral disc herniation as an underlying pathology (30.7% vs 9.2%, p < 0.001). CONCLUSIONS: The selection of approach for patients with CSM depends on patient demographics and symptomology. Posterior surgery was performed in patients who were older and had worse systemic disease, increased myelopathy, and greater levels of stenosis. Anterior surgery was more often performed in patients who were employed and had intervertebral disc herniation.


Assuntos
Deslocamento do Disco Intervertebral , Doenças da Medula Espinal , Fusão Vertebral , Espondilose , Humanos , Idoso , Resultado do Tratamento , Deslocamento do Disco Intervertebral/cirurgia , Espondilose/cirurgia , Fusão Vertebral/efeitos adversos , Estudos Retrospectivos , Estudos Prospectivos , Doenças da Medula Espinal/cirurgia , Doenças da Medula Espinal/etiologia , Vértebras Cervicais/cirurgia , Descompressão Cirúrgica
7.
Sensors (Basel) ; 23(17)2023 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-37687822

RESUMO

A vision of 6G aims to automate versatile services by eliminating the complexity of human effort for Industry 5.0 applications. This results in an intelligent environment with cognitive and collaborative capabilities of AI conversational orchestration that enable a variety of applications across smart Autonomous Vehicle (AV) networks. In this article, an innovative framework for AI conversational orchestration is proposed by enabling on-the-fly virtual infrastructure service orchestration for Anything-as-a-Service (XaaS) to automate a network service paradigm. The proposed framework will potentially contribute to the growth of 6G conversational orchestration by enabling on-the-fly automation of cloud and network services. The orchestration aspect of the 6G vision is not limited to cognitive collaborative communications, but also extends to context-aware personalized infrastructure for 6G automation. The experimental results of the implemented proof-of-concept framework are presented. These experiments not only affirm the technical capabilities of this framework, but also push into several Industry 5.0 applications.

8.
Sensors (Basel) ; 23(13)2023 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-37447666

RESUMO

The roadside unit (RSU) is one of the fundamental components in a vehicular ad hoc network (VANET), where a vehicle communicates in infrastructure mode. The RSU has multiple functions, including the sharing of emergency messages and the updating of vehicles about the traffic situation. Deploying and managing a static RSU (sRSU) requires considerable capital and operating expenditures (CAPEX and OPEX), leading to RSUs that are sparsely distributed, continuous handovers amongst RSUs, and, more importantly, frequent RSU interruptions. At present, researchers remain focused on multiple parameters in the sRSU to improve the vehicle-to-infrastructure (V2I) communication; however, in this research, the mobile RSU (mRSU), an emerging concept for sixth-generation (6G) edge computing vehicular ad hoc networks (VANETs), is proposed to improve the connectivity and efficiency of communication among V2I. In addition to this, the mRSU can serve as a computing resource for edge computing applications. This paper proposes a novel energy-efficient reservation technique for edge computing in 6G VANETs that provides an energy-efficient, reservation-based, cost-effective solution by introducing the concept of the mRSU. The simulation outcomes demonstrate that the mRSU exhibits superior performance compared to the sRSU in multiple aspects. The mRSU surpasses the sRSU with a packet delivery ratio improvement of 7.7%, a throughput increase of 5.1%, a reduction in end-to-end delay by 4.4%, and a decrease in hop count by 8.7%. The results are generated across diverse propagation models, employing realistic urban scenarios with varying packet sizes and numbers of vehicles. However, it is important to note that the enhanced performance parameters and improved connectivity with more nodes lead to a significant increase in energy consumption by 2%.


Assuntos
Comunicação , Unidades Móveis de Saúde , Humanos , Simulação por Computador , Fenômenos Físicos , Pesquisadores
9.
World Neurosurg ; 176: e91-e100, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37164209

RESUMO

OBJECTIVE: There is increasing interest in performing awake spinal fusion under spinal anesthesia (SA). Evidence supporting SA has been positive, albeit limited. The authors set out to investigate the effects of SA versus general anesthesia (GA) for spinal fusion procedures on length of stay (LOS), opioid use, time to ambulation (TTA), and procedure duration. METHODS: The authors performed a retrospective review of a single surgeon's patients who underwent lumbar fusions under SA versus GA from June of 2020 to June of 2022. SA patients were compared to demographically matched GA counterparts undergoing comparable procedures. Analyzed outcomes include operative time, opioid usage in morphine milligram equivalents, TTA, and LOS. RESULTS: Ten SA patients were matched to 10 GA counterparts. The cohort had a mean age of 66.77, a mean body mass index of 27.73 kg/m2, and a median American Society of Anesthesiologists Physical Status Score of 3.00. LOS was lower in SA versus GA patients (12.87 vs. 50.79 hours, P = 0.001). Opioid utilization was reduced in SA versus GA patients (10.76 vs. 31.43 morphine milligram equivalents, P = 0.006). TTA was reduced in SA versus GA patients (7.22 vs. 29.87 hours, P = 0.022). Procedure duration was not significantly reduced in SA patients compared to GA patients (139.3 vs. 188.2 minutes, P = 0.089). CONCLUSIONS: These preliminary retrospective results suggest the use of SA rather than GA for lumbar fusions is associated with reduced hospital LOS, reduced opioid utilization, and reduced TTA. Future randomized prospective studies are warranted to determine if SA usage truly leads to these beneficial outcomes.


Assuntos
Raquianestesia , Fusão Vertebral , Humanos , Idoso , Estudos de Coortes , Analgésicos Opioides/uso terapêutico , Estudos Retrospectivos , Tempo de Internação , Vigília , Anestesia Geral , Caminhada , Derivados da Morfina
10.
Neurochirurgie ; 69(3): 101444, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37061179

RESUMO

BACKGROUND: Annually, hundreds of thousands of patients undergo surgery for degenerative spine disease (DSD). This represents only a fraction of patients that present for surgical consideration. Procedures are often avoided due to comorbidities that make patients poor candidates for general anesthesia (GA) and its associated risks. With increasing interest in awake surgery under spinal anesthesia (SA), the authors have observed that SA may facilitate spine surgery in patients with relative contraindications to GA. With this in mind, the authors set out to summarize the outcomes of a series of highly comorbid patients who received surgery under SA. METHODS: Case logs of a single surgeon were reviewed, and patients undergoing spine surgery under SA were identified. Within this group, patients were identified with relative contraindications to GA, such as advanced age and medical comorbidities. For these patients, for whom surgery was facilitated by SA, the medical records were consulted to report demographic information and patient outcomes. RESULTS: Ten highly comorbid patients were identified who received lumbar spine surgery for DSD under SA. Comorbidities included octogenarian status, obesity, and chronic health conditions such as heart disease. The cohort had a mean age of 75.5 and a mean American Society of Anesthesiologists Physical Status (ASA-PS) score of 3.1. The patients were predicted to have a 2.74-fold increase of serious complications compared to the average patient. There were no adverse events. CONCLUSION: For patients with symptomatic, refractory DSD and relative contraindications to GA, SA may facilitate safe surgical intervention with excellent outcomes.


Assuntos
Raquianestesia , Neoplasias Encefálicas , Idoso de 80 Anos ou mais , Humanos , Idoso , Raquianestesia/efeitos adversos , Raquianestesia/métodos , Vigília , Anestesia Geral/efeitos adversos , Anestesia Geral/métodos , Coluna Vertebral/cirurgia , Vértebras Lombares
11.
Global Spine J ; 13(2): 334-343, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33583227

RESUMO

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: Spinal chordomas are rare primary malignant neoplasms of the primitive notochord. They are slow growing but locally aggressive lesions that have high rates of recurrence and metastasis after treatment. Gold standard treatment remains en-bloc surgical resection with questionable efficacy of adjuvant therapies such as radiation and chemotherapy. Here we provide a comprehensive analysis of prognostic factors, treatment modalities, and survival outcomes in patients with spinal chordoma. METHODS: Patients with diagnosis codes specific for chordoma of spine, sacrum, and coccyx were queried from the National Cancer Database (NCDB) during the years 2004-2016. Outcomes were investigated using Cox univariate and multivariate regression analyses, and survival curves were generated for comparative visualization. RESULTS: 1,548 individuals were identified with a diagnosis of chordoma, 60.9% of which were at the sacrum or coccyx and 39.1% at the spine. The mean overall survival of patients in our cohort was 8.2 years. Increased age, larger tumor size, and presence of metastases were associated with worsened overall survival. 71.2% of patients received surgical intervention and both partial and radical resection were associated with significantly improved overall survival (P < 0.001). Neither radiotherapy nor chemotherapy administration improved overall survival; however, amongst patients who received radiation, those who received proton-based radiation had significantly improved overall survival compared to traditional radiation. CONCLUSION: Surgical resection significantly improves overall survival in patients with spinal chordoma. In those patients receiving radiation, those who receive proton-based modalities have improved overall survival. Further studies into proton radiotherapy doses are required.

12.
J Spine Surg ; 8(3): 333-342, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36285098

RESUMO

Background: C7 instrumentation during posterior cervicothoracic fusion can be challenging because it requires additional work of either placing side connectors to a single rod or placing two rods. Our clinical observations suggested that skipping instrumentation at C7 in a multi-level posterior cervicothoracic fusion will result in minimal intraoperative complications and decreased blood-loss while still maintaining sagittal balance parameters of cervical fusion. The objective of this study is to determine the clinical and radiographic outcomes of skipping C7 instrumentation compared to instrumenting the C7 vertebra in posterior cervicothoracic fusion. Methods: This is a retrospective chart review of 314 consecutive patients who underwent multilevel posterior cervical fusion (PCF) at our institution. Out of 314 patients, 19 were instrumented at C7 serving as the control group, while the remaining 295 patients were not. Evaluation of efficacy was based on intraoperative complications, operative time, estimated blood loss (EBL), significant long-term complications, and radiographic evidence of fusion. Results: Skipping the C7 level resulted in a significant reduction in EBL (488±576 vs. 822±1,137; P=0.007); however, operative time was similar between groups (174±95 vs. 184±86 minutes; P=0.844). Complications were minimal in both groups and not statistically significant. Radiographic analysis revealed C7 bridge patients had a significantly increased postoperative sagittal vertical axis (SVA) (29.3±13.1 vs. 20.2±3.1 mm; P=0.008); however, there was no significant difference between groups in SVA correction (-0.3±16.2 vs. -16.1±16.0 mm; P=0.867), T1 slope correction (3.4°±9.9° vs. 3.2°±5.5°; P=0.127), or cervical cobb angle correction (-5.7°±14.2° vs. -7.0°±12.2°; P=0.519). There were no significant long-term complications in either group. Conclusions: Skipping instrumentation at C7 in a multilevel posterior cervicothoracic fusion is associated with significantly reduced operative blood loss without loss of radiographic correction. This study demonstrates the clinical benefits of skipping C7 instrumentation in posterior cervicothoracic fusion with maintenance of radiographic correction parameters.

13.
World Neurosurg ; 162: e616-e625, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35339712

RESUMO

OBJECTIVE: Stereotactic intraoperative computer-assisted navigation has been shown to improve pedicle screw accuracy in spinal fusion surgery, but evidence of impact of navigation on clinical outcomes is lacking. The aim of this study is to compare rates of perioperative complications between navigated and nonnavigated procedures for deformity correction. METHODS: An administrative database was queried for adult patients undergoing thoracolumbar fusion procedures for deformity. Nonelective cases and those involving malignancy, infection, or trauma were excluded. Individuals were divided into 2 cohorts based on the use of stereotactic intraoperative navigation and paired 1:1 for comparison based on a propensity score matching algorithm. Rates of unplanned reoperation and other perioperative complications were compared between matched groups. A multivariable Cox regression model was constructed to identify the impact of navigation on specific subgroups. RESULTS: A total of 6150 patients met eligibility criteria for the study; after propensity score matching, 456 patients who underwent conventional fusion were matched to 456 patients receiving intraoperative navigation. Navigated cases took an average of 30 minutes longer than nonnavigated cases. There were no significant differences in rates of complications between cohorts. A subgroup analysis revealed that use of navigation was associated with decreased hazard for reoperation in individuals undergoing interbody fusion. CONCLUSIONS: Despite increased surgical duration, the use of navigation does not seem to significantly impact rates of perioperative complications outside of procedures involving interbody fusion. Surgeons should elect to use navigation in cases expected to be of high operative complexity at their own discretion.


Assuntos
Parafusos Pediculares , Fusão Vertebral , Cirurgia Assistida por Computador , Adulto , Humanos , Duração da Cirurgia , Reoperação , Estudos Retrospectivos , Fusão Vertebral/efeitos adversos , Fusão Vertebral/métodos
14.
Heliyon ; 8(12): e12516, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36619420

RESUMO

The FSO communication system offers high data rate investigated over the last few decades because of extraordinary advantages like unlicensed frequency and bandwidth at low power consumption, simple design, hasty, and minimal installation cost, including no right of way. It is essential to investigate solutions against degrading factors like absorption and scattering caused by fog, dust, rain, smog, and uncertain temperature variation of environmental channels. In this work various modulation techniques (AM, CS-NRZ, CS-RZ, DB-NRZ, MDB-NRZ, MDB-RZ, RZ, NRZ) are simulated and used to mitigate the weather attenuation of the specific airfield of Lahore, Pakistan under fog conditions, to provide a reliable FSO communication link for high data rate up to 40 Gbps over a link distance from 1.2 to 1.8 km at transmitted power up to 34 dBm in congested region. The real-time visibility data was taken metrological department for the estimation of attenuation under fog conditions and simulated using Optisys software for further investigation. To choose an FSO communication link, analysis for data rate, link distance, SNR, BER and Q-factor are performed under fog conditions using eight different modulation techniques. An increase in signal channel loss has been observed under fog conditions and performance of the FSO communication system is degraded consequently. The 3 R's (range, rate, and reliability) depend on each other if the link range is tarnished in a foggy condition that will also degrade the data rate and subsequently, reliability of the FSO system. It is observed that for maximum link distance, the performance parameters of AM modulation technique are prominent and more efficient, offering better Q-factor value at 6.08 dB, lower bit error rate at 7.03 × 10-10, and better SNR of 4.29 dB. The results also show that AM modulation technique offers better signal-to-noise power and has good SNR due to well-received signal power as compared to all other modulation techniques. This research will be helpful to design and implement an FSO communication system under foggy conditions in a metropolitan city to provide a high data communication link among different national institutions.

15.
J Cerebrovasc Endovasc Neurosurg ; 23(3): 251-259, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34492753

RESUMO

Spontaneous intracerebral hemorrhage (ICH) from a traumatic carotid-cavernous fistula (CCF) is a rare occurrence with few cases reported in the literature. Patients classically present shortly after the inciting trauma with symptoms of ocular venous hypertension. We report a case of an ICH due to delayed rupture of a venous aneurysm from a CCF in a patient with decades-old history of enucleation of the left globe secondary to trauma with no sentinel symptoms. Our patient represents a unique presentation of a rare pathology. This case highlights the need for ongoing surveillance in patients with a history of severe craniofacial trauma, as ICH from ruptured CCF(s) demands emergent treatment due to the potential for rapid neurological deterioration.

16.
Neurol Res ; 43(9): 708-714, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33944706

RESUMO

Background: The optimal timing of ventriculoperitoneal shunt (VPS) and gastrostomy placement, relative to the safety of simultaneous versus staged surgery, has not been clearly delineated in the literature.Objective: To study the optimal inter-procedural timing relative to distal VPS infection and pertinent reoperation.Methods: A fifteen-year, retrospective, single-center study was conducted on adults undergoing VPS and gastrostomy within 30-days. Patients were grouped according to inter-procedural interval: 0-24 hr (immediate), 24 hr-7 days (early), and 7-30 days (delayed). The primary endpoint of the study was VPS infection and distal shunt complications requiring reoperation. Potential predictors of the primary end point (baseline cohort characteristics, procedural factors) were examined with standard statistical methods.Results: A total of 188 patients met inclusion criteria. The average interval between procedures was 7 ± 6 days, with 43.1% undergoing VPS prior to gastrostomy. Primary endpoint was encountered in 5 patients (2.7%): 1 (5.9%) of 17 patients undergoing immediate placement, 3 (2.8%) of 107 with early placement, and 1 (1.6%) of 64 with delayed placement. Although not statistically significant, 3.7% of patients undergoing VPS first had the primary endpoint, compared to 1.9% of those with gastrostomy. There were no statistically significant associations between the primary outcome and peri-operative CSF counts, gastrostomy modality, hydrocephalus etiology, chronic steroid use, or extended antibiotic administration.Conclusion: Although the low overall event rate in this cohort precludes definitive determination regarding differential safety, the data generally support a practice of performing the procedures >24-hours apart, with placement of gastrostomy prior to VPS.


Assuntos
Gastrostomia/efeitos adversos , Gastrostomia/métodos , Derivação Ventriculoperitoneal/efeitos adversos , Derivação Ventriculoperitoneal/métodos , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/etiologia , Reoperação , Estudos Retrospectivos
17.
World Neurosurg ; 150: 71-83, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33785427

RESUMO

BACKGROUND: Chondrosarcomas of the skull base are rare intracranial tumors of chondroid origin. The rarity of these lesions has made it difficult to form a consensus on optimal treatment regimens. The aim of this study was to provide a comprehensive analysis of prognostic factors, treatment modalities, and survival outcomes in patients with chondrosarcoma of the skull base. METHODS: Patients with diagnosis codes for chondrosarcoma of the skull base were queried from the National Cancer Database for the years 2004-2016. Outcomes were investigated using Cox univariate and multivariate regression analyses, and survival curves were generated for comparative visualization. RESULTS: A total of 718 patients with chondrosarcoma of the skull base were identified. Mean overall survival (OS) in these patients was 10.7 years. Older age and presence of metastases were associated with worsened OS. Of patients, 83.3% received surgical intervention, and both partial resection and radical resection were associated with significantly improved OS (P < 0.001). Neither radiotherapy nor chemotherapy improved OS; however, patients who received proton-based radiation and patients who received high-dose radiation (≥6000 cGy) had significantly improved OS compared with patients who received traditional radiation. CONCLUSIONS: In the largest study to our knowledge of skull base chondrosarcoma to date, both partial resection and radical resection significantly improved OS, thus supporting the goal of maximal safe resection to preserve vital neurovascular structures without sacrificing outcome. In patients who received radiotherapy, proton-based modalities and high-dose radiation were associated with increased OS.


Assuntos
Condrossarcoma/diagnóstico , Condrossarcoma/terapia , Neoplasias da Base do Crânio/diagnóstico , Neoplasias da Base do Crânio/terapia , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação de Processos e Resultados em Cuidados de Saúde , Modelos de Riscos Proporcionais , Resultado do Tratamento , Estados Unidos , Adulto Jovem
18.
World Neurosurg ; 150: e530-e538, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33746104

RESUMO

BACKGROUND: Computer-assisted navigation (CAN) has been shown to improve accuracy of screw placement in procedures involving the posterior cervical spine, but whether the addition of CAN affects complication rates, neurologic or otherwise, is presently unknown. The objective of this study is to determine the effect of spinal CAN on short-term clinical outcomes following posterior cervical fusion. METHODS: The American College of Surgeons National Surgical Quality Improvement Program database was queried from 2011 to 2018. Patients receiving posterior cervical fusion were identified and separated into CAN and non-CAN cohorts on the basis of a propensity score matching algorithm to select similar patients for comparison. Rates of 30-day unplanned readmission, reoperation, and other complications were evaluated. A separate matching algorithm was used to generate a subgroup of patients undergoing C1-C2 or occiput-C2 fusion for comparison of the same outcomes. RESULTS: A total of 12,578 patients met inclusion criteria, of which 689 received CAN and 11,889 did not. After adjusting for baseline differences, patients receiving CAN experienced longer operations and had higher total relative value units associated with care. There were no significant differences in 30-day complication, readmission, or revision rates. At the occipitocervical junction, there were more hardware revisions in the non-CAN group, but this effect did not reach statistical significance (2 vs. 0; P = 0.155). CONCLUSIONS: Surgeons should embrace navigation in the cervical spine at their own discretion, as use of CAN does not appear to be associated with increased rates of surgical complications or readmissions despite longer operative time.


Assuntos
Neuronavegação/métodos , Complicações Pós-Operatórias , Fusão Vertebral/efeitos adversos , Fusão Vertebral/métodos , Adolescente , Adulto , Idoso , Vértebras Cervicais/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Readmissão do Paciente/estatística & dados numéricos , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Pontuação de Propensão , Reoperação/estatística & dados numéricos , Estudos Retrospectivos , Adulto Jovem
19.
World Neurosurg ; 148: e527-e535, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33460817

RESUMO

BACKGROUND: Spinal hemangiomas are common primary tumors of the vertebrae. Although these tumors are most frequently benign and asymptomatic, they can rarely exhibit aggressive growth and invasion into neighboring structures. Treatment for these aggressive variants is controversial, often involving surgery, chemotherapy, and/or radiotherapy. This study sought to investigate current trends affecting overall survival (OS) using the National Cancer Database (NCDB) and to formulate treatment recommendations. METHODS: The National Cancer Database was queried for spinal hemangiomas between 2004 and 2016. A Cox proportional hazards model was used to perform multivariate regression analysis of survival. Survival curves for comparative visualization of demographic and treatment factors were generated using a semiparametric Cox approach. RESULTS: A cohort of 102 patients with histologically confirmed spinal hemangiomas was identified in the database. Mean OS was 1.94 years. Administered treatments included partial surgical resection (n = 17), radical resection (n = 14), chemotherapy (n = 34), and radiotherapy (n = 56). Multivariate analysis revealed associations between decreased OS and advanced age (>65 years) and presence of metastasis. Cox survival analysis further revealed improved OS in patients who received surgical treatment and higher radiation dose. CONCLUSIONS: This retrospective analysis finding that treatment with surgical resection and/or radiotherapy is associated with increased OS constitutes the largest cohort of patients with aggressive vertebral hemangiomas to date. Given that the mean OS of the study cohort was 1.94 years, our findings suggest that the optimal treatment regimen to maximize survival should consist of early surgical resection with adjuvant high-dose radiotherapy.


Assuntos
Hemangioma/terapia , Neoplasias da Coluna Vertebral/terapia , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Quimiorradioterapia , Estudos de Coortes , Terapia Combinada , Bases de Dados Factuais , Feminino , Hemangioma/tratamento farmacológico , Hemangioma/cirurgia , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Modelos de Riscos Proporcionais , Doses de Radiação , Estudos Retrospectivos , Neoplasias da Coluna Vertebral/tratamento farmacológico , Neoplasias da Coluna Vertebral/cirurgia , Análise de Sobrevida , Resultado do Tratamento , Estados Unidos , Adulto Jovem
20.
World Neurosurg ; 141: 284-290, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32450307

RESUMO

BACKGROUND: Primary intracranial leiomyoma is a rare smooth muscle tumor often associated with Epstein-Barr virus (EBV), with <30 cases reported worldwide. These tumors commonly occur in patients with immunocompromised status, especially those with human immunodeficiency virus. In the present report, we have described the case of an EBV-associated leiomyoma at the cerebellopontine angle. The patient had presented with trigeminal neuralgia, which, to the best of our knowledge, is the first reported anatomical location and presentation for this tumor type. CASE DESCRIPTION: A 41-year-old male patient had presented with right-sided facial pain in the V1 and V2 dermatomes and previous workup and imaging studies. The patient had undergone treatment of a presumed right-side cerebellopontine angle meningioma as determined by the magnetic resonance imaging characteristics (no biopsy). The patient subsequently underwent right-sided retrosigmoid craniotomy and gross total resection of the tumor. The postoperative period was uneventful with resolution of the trigeminal neuralgia. Histopathologic examination revealed spindle cell neoplasm with histopathologic and immunohistochemical features consistent with leiomyoma. The tumor cells were positive for smooth muscle actin and desmin and were negative for S100, SOX-10, epithelial membrane antigen, glial fibrillary acidic protein, progesterone receptor, CD31, CD34, and E-cadherin. CONCLUSIONS: Primary intracranial leiomyomas are rare tumors associated with EBV infection that occur in immunocompromised patients. These lesions should be considered in the differential diagnosis for patients with known immunocompromised status (e.g., human immunodeficiency virus), and tissue biopsy should be considered.


Assuntos
Encéfalo/virologia , Ângulo Cerebelopontino/cirurgia , Infecções por Vírus Epstein-Barr/cirurgia , Leiomioma/virologia , Neuralgia do Trigêmeo/cirurgia , Adulto , Encéfalo/cirurgia , Ângulo Cerebelopontino/virologia , Craniotomia/métodos , Diagnóstico Diferencial , Infecções por Vírus Epstein-Barr/complicações , Infecções por Vírus Epstein-Barr/diagnóstico , Humanos , Leiomioma/diagnóstico , Leiomioma/cirurgia , Masculino , Neuroma Acústico/cirurgia , Neuralgia do Trigêmeo/virologia
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