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INTRODUCTION: Despite its rising popularity, little has been described about locum tenens employment (locums) in neurosurgery. This study provides the first nationwide overview of the locums neurosurgery experience. METHODS: An anonymous online survey examined practice characteristics of respondents, extent of and satisfaction with locums, motivations for pursuing locums, case volumes, agencies used, compensation, and positive/negative aspects of experiences. Responses were collected between November 2020 and February 2021. RESULTS: Response rate for the 1852 neurosurgeons who opened the survey request was 4.9%; 36 of 91 respondents had previously worked locums and were commonly motivated by compensation or transitioning to new jobs or retirement. In our response group, 92% of locums respondents had taken more than one position and 47% had taken more than 10. Neurosurgeons performing <200 cases/year were significantly more likely to have also worked locums than those performing >200 cases/year (41.6% locums, 12.7% non-locums, P = 0.001). Responses showed that 69% of locums respondents earned $2000-$2999/day and 16% earned >$3500/day. Nearly 78% of locums respondents were satisfied with their experience(s) and 86% would take another future locums position. Being in practice for >15 years was significantly associated with satisfaction with locums (P = 0.03). Reported flaws included unfamiliarity with hospitals, limited continuity of care, credentialing burdens, and inadequate travel compensation. CONCLUSIONS: Locums is utilized by neurosurgeons across multiple practice types and may serve to complement workloads or "fill in gaps" between longer-term employment. Overall, locums neurosurgeons are well compensated, and the majority are satisfied with their experience(s). Inevitably, flaws still exist with locums employment, which may be the focus of organized efforts aiming to improve the experience.
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Neurocirugia , Humanos , Hospitales , Procedimientos Neuroquirúrgicos , Neurocirujanos , Carga de TrabajoRESUMEN
BACKGROUND: Minimally Invasive Spine Surgery (MISS) is a growing alternative to Open Spine Surgery (OSS). The preservation of musculature and minimization of iatrogenic injury is hypothesized to decrease the need for reoperation by preserving normal anatomy. Our objective is to compare the relative long-term reoperation rates after MISS and OSS for the treatment of degenerative disease of the lumbar spine. METHODS: This retrospective analysis compares the long-term reoperation rates after MISS and OSS. Eligible patients were adults with a primary lumbar intervention carried out between 5/1/2004 and 1/31/2014 to allow for at least 5 years of follow up. Patients without sufficient descriptive metrics or follow-up data were excluded. The primary outcome was the rate of lumbar spine reoperation. RESULTS: A total of 2130 patients met the inclusion criteria-1895 underwent OSS and 235 underwent MISS. On average and across all surgery types (decompression and decompression with fusion), 28% of OSS patients required reoperation during the minimum 5-year follow up period while only 14% of MISS patients required reoperation (P = 0.001). The MISS group was statistically identical to the OSS group in all categories except that the MISS group was on average 1.8 years older (62.25 vs. 60.45, P = 0.039) and had a higher incidence of diabetes (26% vs. 17%, P = 0.000), but had a lower average body mass index than the OSS group (28.35 vs. 29.60, P = 0.002). CONCLUSIONS: In the setting of degenerative lumbar spine disease, MISS has the potential to reduce the long-term need for reoperation when compared with OSS.
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Vértebras Lumbares , Fusión Vertebral , Adulto , Humanos , Estudios Retrospectivos , Reoperación , Estudios de Seguimiento , Vértebras Lumbares/cirugía , Segunda Cirugía , Procedimientos Quirúrgicos Mínimamente Invasivos , Resultado del TratamientoRESUMEN
Human mesenchymal stem cells (MSCs) are isolated from various adult and perinatal tissues. Although mesenchymal stem cells from multiple sources exhibit similar morphology and cell surface markers, they differ in their properties. In this study, we determined that the expression of integrin alpha 6 (ITGA6) and ITGA6 antisense RNA (ITGA6-AS1) correlates with the proliferation, cell size, and differentiation potential. The expression of ITGA6 was inversely correlated with ITGA6-AS1 in MSCs. The expression of ITGA6 was higher, but ITGA6-AS1 was lower in MSCs from cord placenta junction, cord tissue, and Wharton's jelly. In contrast, ITGA6 expression was lower, while ITGA6-AS1 was higher in MSCs from the placenta. The bioinformatic analysis showed that ITGA6 genomic DNA transcribes ITGA6-AS1 from the reverse strand, overlapping ITGA6 exon-2. Additionally, we identify several putative promoters (P1-P10) of ITGA6. ITGA6-P10 is CG rich and contains CGI. EMBOSS Cpgplot software revealed a CGI length of 180 bp that extends from nucleotide 125 to 304 of the P10 sequence. We suggest that the post-transcriptional regulation of the ITGA6 in mesenchymal stem cells is controlled by the ITGA6-AS1, which could be a critical factor responsible for the heterogeneity in function and cell fate of human MSCs. These results may provide further impetus for investigations to unravel the mechanisms of ITGA6 regulation that could help maintain or improve the properties of mesenchymal stem cells.
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Minimally-Invasive robotic spine surgery (MARSS) has expanded the surgeons armamentarium to treat a variety of spinal disorders. In the last decade, robotic developments in spine surgery have improved the safety, accuracy and efficacy of instrumentation placement. Additionally, robotic instruments have been applied to remove tumors in difficult locations while maintaining minimally invasive access. Gross movements by the surgeon are translated into fine, precise movements by the robot. This is exemplified in this chapter with the use of the da Vinci robot to remove apical thoracic tumors. In this chapter, we will review the development, technological advancements, and cases that have been conducted using MARSS to treat spine pathology in a minimally invasive fashion.
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OBJECTIVE: Few studies have investigated the financial influence of surgical site local morselized bone autograft (LMBA) on the overall cost of spinal arthrodesis procedures. The purpose of this study is to evaluate the potential savings from introducing LMBA in spinal fusion procedures compared with no LMBA use. METHODS: Retrospectively, cost analysis was conducted on a single-center data collected from 266 patients who underwent minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) ranging from L1 through S1 during a period of approximately 4 years. Cost data were obtained from individual patient invoices from the distributor. Sensitivity analyses were also conducted for different costs of allograft and LMBA. RESULTS: A total of 282 levels were grafted in 266 subjects. The total quantity of LMBA harvested was 2433.5 mL, and a total of 1610 mL of allograft (Trinity Elite, ORTHOFIX, Lewisville, Texas, USA) were used. The overall cost savings from introducing LMBA in MI-TLIF surgery were $1,094,931 over the 4-year period with mean direct cost saving of $4116.28 per patient based on reduction in allograft. Results for cost savings per patient were sensitive to different direct costs of allograft and LMBA. A >95% fusion rate was achieved based on dynamic radiographs evaluated by an independent radiologist. CONCLUSIONS: LMBA is a cost-saving bone graft extender option in MI-TLIF procedures while achieving high fusion rates. The savings are mainly achieved by reducing the amount of allograft needed and subsequent reduction in the total bone graft costs. Further research needs to be performed regarding long-term economic benefit.
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Autoinjertos/economía , Trasplante Óseo/economía , Costos y Análisis de Costo , Vértebras Lumbares/cirugía , Procedimientos Quirúrgicos Mínimamente Invasivos/economía , Adulto , Anciano , Anciano de 80 o más Años , Trasplante Óseo/métodos , Femenino , Humanos , Degeneración del Disco Intervertebral/cirugía , Región Lumbosacra/cirugía , Masculino , Persona de Mediana Edad , Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Complicaciones Posoperatorias/cirugía , Radiografía/economía , Fusión Vertebral/economía , Fusión Vertebral/métodos , Adulto JovenRESUMEN
BACKGROUND: With the COVID-19 pandemic disrupting many facets of our society, physicians and patients have begun using telemedicine as a platform for the delivery of health care. One of the challenges in implementing telemedicine for the spine care provider is completing a comprehensive spinal examination. Currently, there is no standardized methodology to complete a full spinal examination through telemedicine. METHODS: We propose a novel, remote spinal examination methodology that is easily implemented through telemedicine, where the patient is an active participant in the successful completion of his or her examination. This type of examination has been validated in a neurology setting. To facilitate the telemedicine visit, we propose that video instruction be shared with the patient prior to the telemedicine visit to increase the efficacy of the examination. RESULTS: Since the issuance of stay-at-home order across the states, many spine practices around the country have rapidly adopted and increased their telemedicine program to continue provide care for patients during COVID-19 pandemic. At a tertiary academic center in a busy metropolitan area, nearly 700 telemedicine visits were successfully conducted during a 4-week period. There were no remote visits being done prior to the shutdown. CONCLUSIONS: Implementation of our proposed remote spinal examination has the potential to serve as a guideline for the spine care provider to efficiently assess patients with spine disease using telemedicine. Because these are only suggestions, providers should tailor examination to each individual patient's needs. LEVEL OF EVIDENCE: V. CLINICAL RELEVANCE: It is likely that physicians will incorporate telemedicine into health care delivery services even after the COVID-19 pandemic subsides because of telemedicine's efficiency in meeting patient needs. Using the standard maneuvers provided in our study, spine care providers can perform a nearly comprehensive spine examination through telemedicine. Further studies will be needed to validate the reproducibility and reliability of our methodology.
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BACKGROUND: Degenerative disc disease (DDD) is a common spinal disorder that manifests with neck and lower back pain caused by the degeneration of intervertebral discs (IVDs). Currently, there is no treatment to cure this debilitating ailment. OBJECTIVE: To investigate the potential of nucleus pulposus (NP)-like cells (NPCs) derived from human umbilical cord mesenchymal stem cells (MSCs) to restore degenerated IVDs using a rabbit DDD model. METHODS: NPCs differentiated from MSCs were characterized using quantitative real-time reverse transcription polymerase chain reaction and immunocytochemical analysis. MSCs and NPCs were labeled with fluorescent dye, PKH26, and transplanted into degenerated IVDs of a rabbit model of DDD (n = 9 each). Magnetic resonance imaging of the IVDs was performed before and after IVD degeneration, and following cell transplantation. IVDs were extracted 8 wk post-transplantation and analyzed by various biochemical, immunohistological, and molecular techniques. RESULTS: NPC derivatives of MSCs expressed known NP-specific genes, SOX9, ACAN, COL2, FOXF1, and KRT19. Transplanted cells survived, dispersed, and integrated into the degenerated IVDs. IVDs augmented with NPCs showed significant improvement in the histology, cellularity, sulfated glycosaminoglycan and water contents of the NP. In addition, expression of human genes, SOX9, ACAN, COL2, FOXF1, KRT19, PAX6, CA12, and COMP, as well as proteins, SOX9, ACAN, COL2, and FOXF1, suggest NP biosynthesis due to transplantation of NPCs. Based on these results, a molecular mechanism for NP regeneration was proposed. CONCLUSION: The findings of this study demonstrating feasibility and efficacy of NPCs to regenerate NP should spur interest for clinical studies to treat DDD using cell therapy.
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Degeneración del Disco Intervertebral/patología , Trasplante de Células Madre Mesenquimatosas/métodos , Núcleo Pulposo/trasplante , Animales , Diferenciación Celular/fisiología , Femenino , Sangre Fetal/citología , Xenoinjertos , Humanos , Conejos , Regeneración/fisiologíaRESUMEN
Radiocontrast dyes are used for a wide range of diagnostic procedures for enhancing the image of anatomical structures, pain targets, and vascular uptake. While some of these dyes show toxicity to primary cells, their effect on stem cells, particularly mesenchymal stem cells (MSCs), is unknown. This study investigates the cytotoxic effects of two clinically used radiocontrast dyes, iohexol and iopamidol, on bone marrow and human umbilical cord MSCs. Exposure to these dyes significantly affected morphology of MSCs from both sources, as treated cells appeared transparent and no longer fibroblastoid. Cell viability decreased as determined by trypan blue and Annexin-V/PI staining, in a dose dependent manner with simultaneous loss of CD90 and CD105 concurrent with spontaneous differentiation in MSCs treated with iohexol and iopamidol. In addition, significantly higher cell death was observed in MSCs exposed to iopamidol than iohexol. At a concentration of 1:1, iohexol and iopamidol induced apoptosis in 19% and 92% (<.01) of MSCs, respectively. Global transcriptome analysis of treated MSCs revealed 139 and 384 differentially expressed genes in iohexol vs control and iopamidol vs control at pâ¯≤â¯.01 and 1.5-fold, respectively. This suggested that iopamidol had more significant effect on the transcription of MSCs. Based on these results a molecular mechanism of radiocontast dye induced cell death via intrinsic apoptosis pathway mediated by p53 was proposed. Since iopamidol was significantly more toxic than iohexol in human MSCs, a more careful examination of safety of radiocontrast dyes for clinical use is warranted.
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Medios de Contraste/toxicidad , Células Madre Mesenquimatosas/efectos de los fármacos , Cordón Umbilical/citología , Apoptosis/efectos de los fármacos , Células de la Médula Ósea/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Femenino , Expresión Génica/efectos de los fármacos , Genes p53/efectos de los fármacos , Humanos , Yohexol/toxicidad , Yopamidol/toxicidad , Análisis por Micromatrices , Embarazo , Transcriptoma/efectos de los fármacosRESUMEN
Intervertebral disc (IVD) degeneration is characterized by the loss of nucleus pulposus (NP), which is a common cause for lower back pain. Although, currently, there is no cure for the degenerative disc disease, stem cell therapy is increasingly being considered for its treatment. In this study, we investigated the feasibility and efficacy of human umbilical cord mesenchymal stem cells (MSCs) and chondroprogenitor cells (CPCs) derived from those cells to regenerate damaged IVD in a rabbit model. Transplanted cells survived, engrafted and dispersed into NP in situ. Significant improvement in the histology, cellularity, extracellular matrix proteins, and water and glycosaminoglycan contents in IVD recipients of CPCs was observed compared to MSCs. In addition, IVDs receiving CPCs exhibited higher expression of NP-specific human markers, SOX9, aggrecan, collagen 2, FOXF1 and KRT19. The novelty of the study is that in vitro differentiated CPCs derived from umbilical cord MSCs, demonstrated far greater capacity to regenerate damaged IVDs, which provides basis and impetus for stem cell based clinical studies to treat degenerative disc disease. Copyright © 2016 John Wiley & Sons, Ltd.
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Disco Intervertebral/fisiopatología , Regeneración , Cordón Umbilical/citología , Animales , Biomarcadores/metabolismo , Diferenciación Celular , Condrogénesis , Femenino , Humanos , Disco Intervertebral/patología , Degeneración del Disco Intervertebral/patología , Degeneración del Disco Intervertebral/fisiopatología , Degeneración del Disco Intervertebral/terapia , Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas/citología , Núcleo Pulposo/patología , Núcleo Pulposo/fisiopatología , ConejosRESUMEN
Calcinosis in CREST (calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, and telangiectasia) syndrome can affect the spinal and paraspinal areas. We present the first case to our knowledge where a CREST syndrome patient required surgery for spinal calcinosis in both the cervical and lumbar areas. A 66-year-old female with a history of CREST syndrome presented with right-sided lower extremity radicular pain. A computed tomography (CT) scan showed bilateral lumbar masses (5.8 cm on the right, 3.8 cm on the left) that projected into the foramina and into the spinal canal. The patient underwent minimally invasive bilateral surgical resection of the paraspinal masses, posterior decompressive laminectomy, posterior interbody, and posterolateral fusion. The specimen was consistent with the calcinosis of CREST syndrome. The patient's lumbar symptoms were relieved, however, two years later she presented with right radicular arm pain. A CT scan revealed a large lobulated benign tumor-like lesion on the left at C6-C7 encroaching upon the neural foramen and a large right lobulated lesion encroaching into the neural foramen with severe compression of the neural foramen at the C7-T1 level and extension into the canal, with anterior and posterior subluxation present throughout the cervical spine. Surgery was performed, which involved cervical mass resections, posterior spinal cord decompression, reconstruction, and fusion. The patient did well and has been symptom-free since her surgery. Calcinosis of the spine is a known entity that can cause morbidity in patients with CREST syndrome. Minimal invasive surgical approaches are effective and can be considered for some of these patients.
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The human umbilical cord (UC) and placenta are non-invasive, primitive and abundant sources of mesenchymal stromal cells (MSCs) that have increasingly gained attention because they do not pose any ethical or moral concerns. Current methods to isolate MSCs from UC yield low amounts of cells with variable proliferation potentials. Since UC is an anatomically-complex organ, differences in MSC properties may be due to the differences in the anatomical regions of their isolation. In this study, we first dissected the cord/placenta samples into three discrete anatomical regions: UC, cord-placenta junction (CPJ), and fetal placenta (FP). Second, two distinct zones, cord lining (CL) and Wharton's jelly (WJ), were separated. The explant culture technique was then used to isolate cells from the four sources. The time required for the primary culture of cells from the explants varied depending on the source of the tissue. Outgrowth of the cells occurred within 3 - 4 days of the CPJ explants, whereas growth was observed after 7 - 10 days and 11 - 14 days from CL/WJ and FP explants, respectively. The isolated cells were adherent to plastic and displayed fibroblastoid morphology and surface markers, such as CD29, CD44, CD73, CD90, and CD105, similarly to bone marrow (BM)-derived MSCs. However, the colony-forming efficiency of the cells varied, with CPJ-MSCs and WJ-MSCs showing higher efficiency than BM-MSCs. MSCs from all four sources differentiated into adipogenic, chondrogenic, and osteogenic lineages, indicating that they were multipotent. CPJ-MSCs differentiated more efficiently in comparison to other MSC sources. These results suggest that the CPJ is the most potent anatomical region and yields a higher number of cells, with greater proliferation and self-renewal capacities in vitro. In conclusion, the comparative analysis of the MSCs from the four sources indicated that CPJ is a more promising source of MSCs for cell therapy, regenerative medicine, and tissue engineering.
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Células Madre Mesenquimatosas/fisiología , Placenta/citología , Cordón Umbilical/citología , Gelatina de Wharton/citología , Diferenciación Celular , Separación Celular/métodos , Femenino , Humanos , EmbarazoRESUMEN
Background Minimally invasive laminectomy is a very effective surgical method for treating lumbar stenosis. However, this technique can be technically difficult, especially in patients suffering from severe stenosis. The contralateral decompression from a unilateral approach can result in durotomy during removal of the hypertrophied ligamentum flavum. This complication can be difficult to treat through a small working channel. Objective To detail our group's operative experience with the CO2 laser and discuss our results and previous studies in the literature reporting results. Methods The CO2 laser (Omniguide, Boston, MA) was investigated in the surgical ablation of the contralateral ligamentum flavum during minimally invasive laminectomies. Forty levels have been investigated thus far. The amount of voltage needed to adequately desiccate and remove the ligamentum flavum safely as well as the effectiveness of this technique were investigated. Results The contralateral ligamentum flavum could be removed effectively using the 9 to 11 watt continuous wavelength (10,600 nanometer) power setting on the CO2 laser. Shrinkage of the contralateral ligamentum flavum facilitated its removal using a number 2 Kerrison Punch. No durotomies occurred, and the use of the laser did not significantly lengthen operative times. Conclusions The CO2 laser appears to be a useful tool in the armamentarium of instruments available to the minimally invasive spine surgeon and may help to reduce the incidence of durotomies when performing minimally invasive laminectomies.
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Human umbilical cord (hUC) blood and tissue are non-invasive sources of potential stem/progenitor cells with similar cell surface properties as bone marrow stromal cells (BMSCs). While they are limited in cord blood, they may be more abundant in hUC. However, the hUC is an anatomically complex organ and the potential of cells in various sites of the hUC has not been fully explored. We dissected the hUC into its discrete sites and isolated hUC cells from the cord placenta junction (CPJ), cord tissue (CT), and Wharton's jelly (WJ). Isolated cells displayed fibroblastoid morphology, and expressed CD29, CD44, CD73, CD90, and CD105, and showed evidence of differentiation into multiple lineages in vitro. They also expressed low levels of pluripotency genes, OCT4, NANOG, SOX2 and KLF4. Passaging markedly affected cell proliferation with concomitant decreases in the expression of pluripotency and other markers, and an increase in chondrogenic markers. Microarray analysis further revealed the differences in the gene expression of CPJ-, CT- and WJ-hUC cells. Five coding and five lncRNA genes were differentially expressed in low vs. high passage hUC cells. Only MAEL was expressed at high levels in both low and high passage CPJ-hUC cells. They displayed a greater proliferation limit and a higher degree of multi-lineage differentiation in vitro and warrant further investigation to determine their full differentiation capacity, and therapeutic and regenerative medicine potential.
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Células Madre/citología , Cordón Umbilical/citología , Antígenos CD/metabolismo , Diferenciación Celular , Linaje de la Célula , Proliferación Celular , Células Cultivadas , Humanos , Inmunofenotipificación , Factor 4 Similar a Kruppel , Proteína Homeótica Nanog/metabolismo , Factor 3 de Transcripción de Unión a Octámeros/metabolismo , Proteínas de Unión al ARN/metabolismo , Células Madre/metabolismo , Gelatina de Wharton/citologíaRESUMEN
Background Context Controversy remains over the use of provocative discography in conjunction with computed tomography (CT) to locate symptomatic intervertebral discs in patients with chronic, low back pain (LBP). The current study explores the relationship between discogenic pain and disc morphology using discography and CT, respectively, and investigates the efficacy of this combined method in identifying surgical candidates for lumbar fusion by evaluating outcomes. Methods 43 consecutive patients between 2006 and 2013 who presented with refractory low back pain and underwent discography and CT were enrolled in the study. For this study, "refractory LBP" was defined as pain symptoms that persisted or worsened after 6 months of non-operative treatments. Concordant pain was defined as discography-provoked LBP of similar character and location with an intensity of ≥ 8/10. Fusion candidates demonstrated positive-level discography and concordant annular tears on CT at no more than two contiguous levels, and at least one negative control disc with intact annulus. Surgical outcomes were statistically analyzed using Visual Analog Scale (VAS), Oswestry Disability Index (ODI), and Short Form-36 (SF-36) for back-related pain and disability preoperatively, and 2 weeks, 3, 6, 12, and 24 months postoperatively. Results Annular tears were found in 87 discs. Concordant pain was reported by 9 (20.9%) patients at L3-L4, 21 (50.0%) at L4-L5, and 34 (82.9%) at L5-S1; pain occurred significantly more often in discs with annular tears than those without (p<0.001). Painless discs were independent of annulus status (p=0.90). 18 (42%) of the original 43 patients underwent lumbar fusion at L3-L4 (n=1(6%)), L4-L5 (n=6 (33%)), L5-S1 (n=5 (28%)), and two-level L4-S1 (n=6 (33%)) via a minimally invasive transforaminal lumbar interbody fusion (MITLIF) approach with the aim to replace the nucleus pulposus with bone graft material. Median follow-up time was 18 months (range: 12-78 months). VAS, ODI, and SF-36 scores demonstrated significant improvements at 10 out of 12 postoperative time points compared with preoperative baseline. Conclusions Lumbar discography with post-discography CT can be an effective method to evaluate patients with discogenic back pain refractory to non-operative treatments. Those patients with one- or two-level high concordant pain scores with associated annular tears and negative control disc represent good surgical candidates for lumbar interbody spinal fusion.
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AIM: To devise a simplified and efficient method for long-term culture and maintenance of embryonic stem cells requiring less frequent passaging. METHODS: Mouse embryonic stem cells (ESCs) labeled with enhanced yellow fluorescent protein were cultured in three-dimensional (3-D) self-assembling scaffolds and compared with traditional two-dimentional (2-D) culture techniques requiring mouse embryonic fibroblast feeder layers or leukemia inhibitory factor. 3-D scaffolds encapsulating ESCs were prepared by mixing ESCs with polyethylene glycol tetra-acrylate (PEG-4-Acr) and thiol-functionalized dextran (Dex-SH). Distribution of ESCs in 3-D was monitored by confocal microscopy. Viability and proliferation of encapsulated cells during long-term culture were determined by propidium iodide as well as direct cell counts and PrestoBlue (PB) assays. Genetic expression of pluripotency markers (Oct4, Nanog, Klf4, and Sox2) in ESCs grown under 2-D and 3-D culture conditions was examined by quantitative real-time polymerase chain reaction. Protein expression of selected stemness markers was determined by two different methods, immunofluorescence staining (Oct4 and Nanog) and western blot analysis (Oct4, Nanog, and Klf4). Pluripotency of 3-D scaffold grown ESCs was analyzed by in vivo teratoma assay and in vitro differentiation via embryoid bodies into cells of all three germ layers. RESULTS: Self-assembling scaffolds encapsulating ESCs for 3-D culture without the loss of cell viability were prepared by mixing PEG-4-Acr and Dex-SH (1:1 v/v) to a final concentration of 5% (w/v). Scaffold integrity was dependent on the degree of thiol substitution of Dex-SH and cell concentration. Scaffolds prepared using Dex-SH with 7.5% and 33% thiol substitution and incubated in culture medium maintained their integrity for 11 and 13 d without cells and 22 ± 5 d and 37 ± 5 d with cells, respectively. ESCs formed compact colonies, which progressively increased in size over time due to cell proliferation as determined by confocal microscopy and PB staining. 3-D scaffold cultured ESCs expressed significantly higher levels (P < 0.01) of Oct4, Nanog, and Kl4, showing a 2.8, 3.0 and 1.8 fold increase, respectively, in comparison to 2-D grown cells. A similar increase in the protein expression levels of Oct4, Nanog, and Klf4 was observed in 3-D grown ESCs. However, when 3-D cultured ESCs were subsequently passaged in 2-D culture conditions, the level of these pluripotent markers was reduced to normal levels. 3-D grown ESCs produced teratomas and yielded cells of all three germ layers, expressing brachyury (mesoderm), NCAM (ectoderm), and GATA4 (endoderm) markers. Furthermore, these cells differentiated into osteogenic, chondrogenic, myogenic, and neural lineages expressing Col1, Col2, Myog, and Nestin, respectively. CONCLUSION: This novel 3-D culture system demonstrated long-term maintenance of mouse ESCs without the routine passaging and manipulation necessary for traditional 2-D cell propagation.
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Minimally invasive spine surgery has its roots in the mid-twentieth century with a few surgeons and a few techniques, but it has now developed into a large field of progressive spinal surgery. A wide range of techniques are now called "minimally invasive," and case reports are submitted constantly with new "minimally invasive" approaches to spinal pathology. As minimally invasive spine surgery has become more mainstream over the past ten years, in this paper we discuss its history and development.
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Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Procedimientos Quirúrgicos Mínimamente Invasivos/tendencias , Columna Vertebral/cirugía , HumanosRESUMEN
STUDY DESIGN: This was a prospective clinical study that took place in an outpatient spine clinic. OBJECTIVE: To demonstrate the short-/long-term outcomes from a large cohort of patients undergoing minimally invasive transforaminal lumbar interbody fusion (MITLIF). SUMMARY OF BACKGROUND DATA: Long-term prospective outcomes in patients undergoing minimally invasive spinal fusion for debilitating back pain has not been well studied. METHODS: Presenting diagnosis was determined from clinical findings and radiographical (radiograph, magnetic resonance image, computed tomographic scan) evaluations preoperatively. Patients were assessed with outcome measures preoperatively, and postoperatively at 2 weeks, 3 months, 6 months, 12 months, 24 months, and annually 2 to 7 years (mean follow-up: 47 mo) final follow-up. The rate of postoperative complications and reoperations at the initial level of MITLIF and adjacent level(s) were followed. Fusion rates were assessed blinded and independently by radiograph. RESULTS: Visual analogue scale scores decreased significantly from 7.0 preoperatively to 3.5 at mean 47-month follow-up. Oswestry Disability Index scores declined from 43.1 preoperatively to 28.2 at mean 47-month follow-up. Short-Form 36 mental component scores increased from 43.8 preoperatively to 49.7 at 47-month follow-up. Short-Form 36 physical component scores increased from 30.6 preoperatively to 39.6 at 47-month follow-up (P < 0.05). CONCLUSION: This prospectively collected outcomes study shows long-term statistically significant clinical outcomes improvement after MITLIF in patients with clinically symptomatic spondylolisthesis and degenerative disc disease with or without stenosis. MITLIF resulted in a high rate of spinal fusion and very low rate of interbody fusion failure and/or adjacent segment disease requiring reoperation while reducing postoperative complications. LEVEL OF EVIDENCE: 3.
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Degeneración del Disco Intervertebral/psicología , Degeneración del Disco Intervertebral/cirugía , Vértebras Lumbares/cirugía , Procedimientos Quirúrgicos Mínimamente Invasivos/psicología , Calidad de Vida/psicología , Fusión Vertebral/psicología , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Estudios de Seguimiento , Humanos , Degeneración del Disco Intervertebral/diagnóstico por imagen , Vértebras Lumbares/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Procedimientos Quirúrgicos Mínimamente Invasivos/tendencias , Estudios Prospectivos , Radiografía , Fusión Vertebral/tendencias , Factores de Tiempo , Resultado del Tratamiento , Adulto JovenRESUMEN
BACKGROUND AND IMPORTANCE: Applications of robotics to minimally invasive spine surgery have produced several benefits while sparing patients the morbidity of traditional open surgery. Minimally invasive spine surgery offers the advantages of less pain and less blood loss, along with quicker recovery and shorter hospital stays. The da Vinci robotic surgical system has recently been adapted to neurosurgical applications. This article details a posterior approach using a tubular retraction system in conjunction with an anterior approach using the da Vinci robot to completely remove large spinal schwannomas with intrathoracic extension. This technique is an example of a novel application of existing technology initially developed for other applications. CLINICAL PRESENTATION: Two patients with large thoracic schwannomas extending into the chest cavity are reviewed. We present images and video of the combined minimally invasive approach used to completely remove the lesions without complications. CONCLUSION: This report describes a novel neurosurgical application of an existing minimally invasive robotic surgical system.
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Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Neurilemoma/cirugía , Robótica/métodos , Cirugía Asistida por Computador/métodos , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Procedimientos Quirúrgicos Mínimamente Invasivos/instrumentación , Robótica/instrumentación , Vértebras TorácicasRESUMEN
Spine surgery as we know it has changed dramatically over the past 2 decades. More patients are undergoing minimally invasive procedures. Surgeons are becoming more comfortable with these procedures, and changes in technology have led to several new approaches and products to make surgery safer for patients and improve patient outcomes. As more patients undergo minimally invasive spine surgery, more long-term outcome and complications data have been collected. The authors describe the common complications associated with these minimally invasive surgical procedures and delineate management options for the spine surgeon.
Asunto(s)
Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Complicaciones Posoperatorias/prevención & control , Enfermedades de la Columna Vertebral/cirugía , Manejo de la Enfermedad , Humanos , Procedimientos Quirúrgicos Mínimamente Invasivos/efectos adversos , Complicaciones Posoperatorias/etiología , Estudios Retrospectivos , Enfermedades de la Columna Vertebral/diagnóstico , Fusión Vertebral/efectos adversos , Fusión Vertebral/métodosRESUMEN
BACKGROUND: Minimally invasive percutaneous pedicle screw instrumentation methods may increase the need for intraoperative fluoroscopy, resulting in excessive radiation exposure for the patient, surgeon, and support staff. Electromagnetic field (EMF)-based navigation may aid more accurate placement of percutaneous pedicle screws while reducing fluoroscopic exposure. We compared the accuracy, time of insertion, and radiation exposure of EMF with traditional fluoroscopic percutaneous pedicle screw placement. METHODS: Minimally invasive pedicle screw placement in T8 to S1 pedicles of eight fresh-frozen human cadaveric torsos was guided with EMF or standard fluoroscopy. Set-up, insertion, and fluoroscopic times and radiation exposure and accuracy (measured with post-procedural computed tomography) were analyzed in each group. RESULTS: Sixty-two pedicle screws were placed under fluoroscopic guidance and 60 under EMF guidance. Ideal trajectories were achieved more frequently with EMF over all segments (62.7% vs. 40%; p = 0.01). Greatest EMF accuracy was achieved in the lumbar spine, with significant improvements in both ideal trajectory and reduction of pedicle breaches over fluoroscopically guided placement (64.9% vs. 40%, p = 0.03, and 16.2% vs. 42.5%, p = 0.01, respectively). Fluoroscopy time was reduced 77% with the use of EMF (22 s vs. 5 s per level; p < 0.0001) over all spinal segments. Radiation exposure at the hand and body was reduced 60% (p = 0.058) and 32% (p = 0.073), respectively. Time for insertion did not vary between the two techniques. CONCLUSIONS: Minimally invasive pedicle screw placement with the aid of EMF image guidance reduces fluoroscopy time and increases placement accuracy when compared with traditional fluoroscopic guidance while adding no additional time to the procedure.