Este estudio fue apoyado por una subvención (CNUH-BRI-2012-02-005) financiado por el Instituto de Investigación Biomédica del Hospital Universitario Nacional de Chonbuk (CNUH-BRI), República de Corea.

El Comité Institucional de Cuidado y Uso de Animales de la Universidad Nacional de Chonbuk aprobó este estudio. El tratamiento, el uso y la manipulación de los animales siguieron todas las directrices y políticas. Mantener la sala de operaciones a 24 ° C. 1. Anestesia <ol><li> Aclimate a los cerdos miniatura, de 12 meses de edad, en la unidad experimental durante al menos una semana. Realizar un examen clínico que mida la frecuencia respiratoria, el calor del corazón y la temperatura corporal. No alimente a cada cerdo en miniatura durante 12 h antes del procedimiento de anestesia. </li><li> Inyecte atropina (0,05 mg / kg) y ketamina (20 mg / kg) / xilaxina (2 mg / kg) en la región lateral del músculo cervical, detrás de la oreja, para la premedicación. </li><li> Después de la sedación, aplicar fuertemente una banda de goma alrededor de la base de la oreja y limpiar el oído con alcohol tópico. </li><li> Coloque un catéter de plástico sobre la aguja en la vena del oído y retire la goma. Confirme que el catéter está colocado correctamente. GripeSh el catéter con solución salina heparinizada y fijar con cinta adhesiva. </li><li> Para la intubación endotraqueal, coloque el cerdo en miniatura en decúbito esternal. Con la ayuda de un asistente, sostener la mandíbula del cerdo con una honda adecuada y abrir la boca. <ol><li> Pase la punta del laringoscopio hacia la cavidad faríngea para desplazar la epiglotis del paladar blando. Utilice la punta de la hoja del laringoscopio para hacer que las cuerdas vocales sean visibles y avance el tubo endotraqueal hacia la tráquea durante la expiración. </li><li> Sentirse por un paso de aire libre para una intubación adecuada y revisar la auscultación torácica para detectar sonidos respiratorios tanto en el lado izquierdo como en el derecho del cerdo en miniatura. </li></ol></li><li> Llene el manguito con el volumen adecuado de aire del tubo endotraqueal con aire usando una jeringa de 10 ml y fije el tubo al hocico con cinta adhesiva. </li><li> Proporcionar una concentración de 2.0% de isoflurano, un anestésico de inhalación para la anestesia prolongada, a través del endotrTubo de intubación. Pruebe los reflejos corneales y palpebrales para confirmar la anestesia y use un ungüento en los ojos para prevenir la sequedad. </li><li> Monitoree el sistema cardiovascular, el sistema respiratorio y la temperatura corporal durante la anestesia al menos cada 5 min hasta que el cerdo en miniatura se recupere. </li><li> 30 min antes de la cirugía de la columna vertebral, aplique 30 mg / kg de cefazolina IV lentamente, la primera generación de antibióticos cefalosporina. </li><li> Administrar 5-10 mL / kg / h de solución salina caliente (37 ° C) usando una línea intravenosa para mantener la homeostasis y proporcionar 50 μg / kg / min de fentanilo para controlar el dolor. </li><li> Después de la cirugía de la columna vertebral, realizar la extubación cuando un fuerte reflejo de deglución es evidente. </li><li> Tome el cerdo en miniatura en una habitación y el monitor hasta que se recupere de la anestesia. Proporcionar alimentos y agua cuando el cerdo en miniatura está completamente consciente. </li><li> Aplique 3 mg / kg de antibiótico enrofloxacino con 4,4 mg / kg de carprofeno diariamente para controlar el dolor durante los primeros 3 días. </li><li> MoniDiariamente hasta la eliminación de las suturas. </li></ol> 2. Cirugía de la columna vertebral <ol><li> Autoclave los tornillos transpedicular y los sistemas de fijador posterior para la esterilización, siguiendo las directrices del fabricante. </li><li> Añada la parte posterior del cerdo en miniatura, aproximadamente a 10 cm del centro hacia la izquierda o la derecha, usando una afeitadora mientras el cerdo esté en decúbito supino. Limpiar la piel con solución de povidona-yodo y alcohol al 70%. </li><li> Haga una incisión longitudinal longitudinal desde el segundo proceso espinoso de la columna lumbar hasta la primera cresta sacra mediana usando un bisturí. Disecar a través del tejido subcutáneo y la fascia hasta la punta de los procesos espinosos. </li><li> Elevar los músculos paraspinal subperiosteally de las láminas subyacentes usando un elevador de Cobb. Disecar a lo largo del proceso espinoso y de la lámina limitada a las articulaciones facetarias. </li><li> Abrir la corteza superficial del punto de entrada (que es justo inferior al proceso mamilar de L3A L5 en ambos lados) con una rebaba o un rongeur. </li><li> Inserte el pasador de guía en un sitio abierto, paralelo a la placa de extremo superior y en un ángulo de 20 ° con el proceso espinoso. Definir el punto de partida ideal utilizando rayos X portátero-anterior / lateral portadores de brazo C o portátiles. </li><li> Insertar una sonda de pedículo hasta 25 mm según la radiografía. Confirmar la trayectoria intraósea completa por pedículo y palpación corporal utilizando un dispositivo de sondeo pedículo. </li><li> Inserte seis tornillos pediculares en el pedículo preparado de L3 a L5 hasta que la cabeza del tornillo quede bien asentada. Apunte la abertura lateral de la cabeza del implante en la dirección deseada y alinee la posición horizontal con la trayectoria del vástago. </li><li> Inserte dos barras en ambos lados de las cabezas de los tornillos pediculares, respectivamente. Coloque la manga y la tuerca en la cabeza del tornillo pedicular usando un mango universal. </li><li> Apriete la tuerca con una llave de tubo recto y apriete firmemente la tuerca con una llave dinamométrica. </li><li> Confirme las posiciones oF los tornillos pediculares mediante radiografías postero-anteriores / laterales portátiles. NOTA: Espere a que el cerdo en miniatura se despierte y compruebe los patrones de la marcha y la función del motor de la pata trasera para determinar si un tornillo ha sido mal implantado. </li><li> Irrigar el sitio de la cirugía con 3 L de solución salina normal usando una jeringa de irrigación de bulbo con succión. </li><li> Coloque un drenaje de silicona en el sitio de la cirugía y sacar la punta de silicona. Cierre los músculos paraspinal y subcutánea usando suturas absorbibles métricas 1.0. Cierre la piel con suturas de nylon de 2.0 métricas no absorbibles. </li><li> Desinfectar el sitio de sutura con povidona-yodo y aplicar un vendaje con gasa esterilizada y cinta adhesiva. </li></ol> 3. Procedimiento de Cosecha <ol><li> A las 12 semanas de postoperatorio, inyectar xilazina (2 mg / kg) y ketamina (10 mg / kg) en la región lateral del músculo cervical, detrás de la oreja, para la premedicación. </li><li> Después de la sedación, administrar 15 mg / kg de KCl directamente en la vena del oídoCateter para la eutanasia. </li><li> Hacer una incisión longitudinal mediana en la lesión de cicatriz de la cirugía anterior. Disecar los tejidos blandos y los músculos paraspinales. </li><li> Exponer el proceso espinoso de las espinas lumbares, laminas, varillas, tuercas y procesos transversales de L3 a L5. </li><li> Retire las tuercas con una llave dinamométrica y varillas. Corte el espacio del disco L2-3 y el espacio del disco L5-S1 usando una sierra oscilante. </li><li> Disecar ambos lados de la parte media y anterior de la columna L3-5 con un elevador Cobb y una pinza de torre. Después de la cosecha, si la columna vertebral no puede ser probada inmediatamente, envolverla en gasa empapada con solución salina y almacenar a -20 ° C. </li></ol>

<ol>
	<li>Greenfield, R. T., Grant, R. E., Bryant, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pedicle+screw+fixation+in+the+management+of+unstable+thoracolumbar+spine+injuries.">Pedicle screw fixation in the management of unstable thoracolumbar spine injuries.</a> Orthop Rev. 21 (6), 701-706 (1992).</li><li>Upasani, V. V., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pedicle+screw+surface+coatings+improve+fixation+in+nonfusion+spinal+constructs.">Pedicle screw surface coatings improve fixation in nonfusion spinal constructs.</a> Spine. 34 (4), 335-343 (2009).</li><li>Halvorson, T. L., Kelley, L. A., Thomas, K. A., Whitecloud, T. S., Cook, S. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+bone+mineral+density+on+pedicle+screw+fixation.">Effects of bone mineral density on pedicle screw fixation.</a> Spine. 19 (21), 2415-2420 (1994).</li><li>Weinstein, J. N., Spratt, K. F., Spengler, D., Brick, C., Reid, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spinal+pedicle+fixation:+reliability+and+validity+of+roentgenogram-based+assessment+and+surgical+factors+on+successful+screw+placement.">Spinal pedicle fixation: reliability and validity of roentgenogram-based assessment and surgical factors on successful screw placement.</a> Spine. 13 (9), 1012-1018 (1988).</li><li>Fini, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biological+assessment+of+the+bone-screw+interface+after+insertion+of+uncoated+and+hydroxyapatite-coated+pedicular+screws+in+the+osteopenic+sheep.">Biological assessment of the bone-screw interface after insertion of uncoated and hydroxyapatite-coated pedicular screws in the osteopenic sheep.</a> J Biomed Mater Res A. 66 (1), 176-183 (2003).</li><li>Kim, D. Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+of+Titanium-Coated+Pedicle+Screws:+In+Vivo+Porcine+Lumbar+Spine+Model.">Evaluation of Titanium-Coated Pedicle Screws: In Vivo Porcine Lumbar Spine Model.</a> World Neurosurg. 91, 163-171 (2016).</li><li>Upasani, V. V., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pedicle+screw+surface+coatings+improve+fixation+in+nonfusion+spinal+constructs.">Pedicle screw surface coatings improve fixation in nonfusion spinal constructs.</a> Spine. 34 (4), 335-343 (2009).</li><li>Smit, T. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+use+of+a+quadrupted+as+an+in+vivo+model+for+the+study+of+the+spine-biomechanical+considrations.">The use of a quadrupted as an in vivo model for the study of the spine-biomechanical considrations.</a> Eur Spine J. 11 (2), 137-144 (2002).</li><li>Aldini, N. N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pedicular+fixation+in+the+osteoporotic+spine:+a+pilot+in+vivo+study+on+long-term+ovariectomized+sheep.">Pedicular fixation in the osteoporotic spine: a pilot in vivo study on long-term ovariectomized sheep.</a> J Orthop Res. 20 (6), 1217-1224 (2002).</li><li>Fini, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biological+assessment+of+the+bone-screw+interface+after+insertion+of+uncoated+and+hydroxyapatite-coated+pedicular+screws+in+the+osteopenic+sheep.">Biological assessment of the bone-screw interface after insertion of uncoated and hydroxyapatite-coated pedicular screws in the osteopenic sheep.</a> J Biomed Mater Res A. 66 (1), 176-183 (2003).</li><li>Branemark, R., Ohrnell, L. O., Skalak, R., Carlsson, L., Branemark, P. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biomechanical+characterization+of+osseointegration:+an+experimental+in+vivo+investigation+in+the+beagle+dog.">Biomechanical characterization of osseointegration: an experimental in vivo investigation in the beagle dog.</a> J Orthop Res. 16 (1), 61-69 (1998).</li><li>McLain, R. F., Yerby, S. A., Moseley, T. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+morphometry+of+L4+vertebrae:+comparison+of+large+animal+models+for+the+human+lumbar+spine.">Comparative morphometry of L4 vertebrae: comparison of large animal models for the human lumbar spine.</a> Spine. 27 (8), E200-E206 (2002).</li><li>Giavaresi, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+preclinical+evaluation+of+the+influence+of+osteoporosis+on+the+anchorage+of+different+pedicle+screw+designs.">In vivo preclinical evaluation of the influence of osteoporosis on the anchorage of different pedicle screw designs.</a> Eur Spine J. 20 (8), 1289-1296 (2011).</li><li>Hasegawa, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hydroxyapatite-coating+of+pedicle+screws+improves+resistance+against+pull-out+force+in+the+osteoporotic+canine+lumbar+spine+model:+a+pilot+study.">Hydroxyapatite-coating of pedicle screws improves resistance against pull-out force in the osteoporotic canine lumbar spine model: a pilot study.</a> Spine J. 5 (3), 239-243 (2005).</li><li>Smorgick, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single-+versus+multilevel+fusion+for+single-level+degenerative+spondylolisthesis+and+multilevel+lumbar+stenosis:+four-year+results+of+the+spine+patient+outcomes+research+trial.">Single- versus multilevel fusion for single-level degenerative spondylolisthesis and multilevel lumbar stenosis: four-year results of the spine patient outcomes research trial.</a> Spine. 38 (10), 797-805 (2013).</li><li>Busscher, I., Ploegmakers, J. J., Verkerke, G. J., Veldhuizen, A. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+anatomical+dimensions+of+the+complete+human+and+porcine+spine.">Comparative anatomical dimensions of the complete human and porcine spine.</a> Eur Spine J. 19 (7), 1104-1114 (2010).</li></ol>

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La evaluación de los tornillos transpediculares en la columna vertebral porcina requiere mucho tiempo y esfuerzo. En primer lugar, el cerdo en miniatura es un animal grande. Para el cuidado de los animales y la anestesia, el investigador necesita un protocolo especializado. En segundo lugar, la cirugía debe mantener un entorno similar al de la cirugía humana. El propósito de evaluar los tornillos pediculares en la columna vertebral porcina es desarrollar un tornillo eficiente que se puede aplicar a los seres humanos...

Transpedicular screw fixation is a gold-standard treatment for degenerative lumbar spine and bursting fracture because it involves three columns of the spine and achieves stabilization1,2. However, most patients who undergo such surgery also have osteoporosis3,4. Many studies have evaluated the fixation strength and the osseointegration status of transpedicular screws, because the loosening of pedicle screws currently in use has been reported in patients with osteoporosis5,6.
The porcine spine is similar to the human spine in terms of size. It is less expensive compared to a primate model7. Furthermore, an in vivo mechanical study has demonstrated that the quadruped porcine spine is essentially loaded in the same way as that of the human spine8, which is why many researchers use porcine spines for studies on the prevention of pedicle screw loosening. However, it takes several months to study pedicle screws in the porcine spine because identifying the long-term stability of pedicle screws takes times. In order to compare different types of screws in the vertebral body, it is necessary to insert the screws in similar positions. Therefore, researchers should be well-acquainted with proper anesthesia techniques, standardized surgical protocols, and harvest procedures before performing any experiments. Here, we describe a detailed method for anesthesia, surgery, and harvest for the evaluation of pedicle screw fixation using a porcine spine model, including ex vivo imaging, histology, and strength testing.

<table><tbody><tr><td>Miniature pig</td><td>OrientBio</td><td></td><td></td></tr><tr><td>Atropine</td><td>Jeil pharmaceutical</td><td>A04900241</td><td>Anesthesia</td></tr><tr><td>Over-the needle plastic catheter</td><td>BD</td><td>REF382412</td><td>Maintenance of IV line</td></tr><tr><td>Ketamine</td><td>Yuhan</td><td>A04502441</td><td>Anesthesia</td></tr><tr><td>Xylazine</td><td>Bayer Korea</td><td>A00800071</td><td>Anesthesia</td></tr><tr><td>Laryngoscope</td><td>Karl storz</td><td></td><td>Intubation</td></tr><tr><td>Endotracheal tube</td><td>Covidien</td><td></td><td>Intubation</td></tr><tr><td>Isoflurane</td><td>JW pharmaceutical Co</td><td>A02104781</td><td>Anesthesia</td></tr><tr><td>Eye ointment</td><td>Hanlim pharma</td><td>A37851721</td><td>Protection of pig&#039;s eye</td></tr><tr><td>Cefazolin</td><td>Donga pharma</td><td>A01503951</td><td>Antibiotics</td></tr><tr><td>Saline</td><td>JW pharmaceutical Co</td><td>A02151392</td><td>Maintenance of fluid homeostasis</td></tr><tr><td>Fentanyl</td><td>Hana pharm</td><td>C03200032</td><td>Pain control</td></tr><tr><td>Enrofloxacin</td><td>Bayer</td><td>93106-60-6&amp;nbsp;</td><td>Antibiotics</td></tr><tr><td>Morphine</td><td>Myungmoon pharma</td><td>C03700091</td><td>Pain control</td></tr><tr><td>Meloxicam</td><td>Boehringer Ingelheim</td><td>A07600711</td><td>Antibiotics</td></tr><tr><td>Povidone-iodine</td><td>Hyundai pharma</td><td></td><td>Wound dressing</td></tr><tr><td>Scalpel blade size 15</td><td>Braun</td><td>&amp;nbsp;I1 BB515</td><td>Skin incision</td></tr><tr><td>Cobb elevator</td><td>Codman</td><td>65-2546</td><td>Dissection of muscle</td></tr><tr><td>Burr</td><td>Medtronic</td><td></td><td>Making of starting point of screw</td></tr><tr><td>Rongeur</td><td>Aesculap</td><td>FO515R</td><td>Making of starting point of screw</td></tr><tr><td>Guide pin (K-wire)</td><td>CE</td><td>01067803</td><td>Guidance of screw trajectory</td></tr><tr><td>C-arm</td><td>GE</td><td>OEC 9800 plus</td><td>Guidance of screw trajectory</td></tr><tr><td>Portable X-ray</td><td>Siemens</td><td>Mobile XP hybrid</td><td>Guidance of screw trajectory</td></tr><tr><td>Pedicle probe</td><td>OtisBiotech</td><td>SPI-02-01</td><td>Guidance of screw trajectory</td></tr><tr><td>Pedicle sounding device</td><td>OtisBiotech</td><td>SPI-03-01</td><td>Guidance of screw trajectory</td></tr><tr><td>Pedicle screw</td><td>OtisBiotech</td><td>MS-40025</td><td></td></tr><tr><td>Posterior fixator systems</td><td>OtisBiotech</td><td></td><td></td></tr><tr><td>Rod&amp;nbsp;</td><td>OtisBiotech</td><td>ROD-60140</td><td>Rigid fixation between screws</td></tr><tr><td>Universal handle</td><td>OtisBiotech</td><td>SPI-08-01</td><td>To fix the screws to the rod</td></tr><tr><td>Straight socket wrench</td><td>OtisBiotech</td><td>SPI-06-01</td><td>To fix the screws to the rod</td></tr><tr><td>counter torque wrench</td><td>OtisBiotech</td><td>SPI-07-01</td><td>To fix the screws to the rod</td></tr><tr><td>Bulb irrigation syringe</td><td>Hyupsug medical</td><td>HS-IR-140</td><td>Irrigation</td></tr><tr><td>Silicone drain</td><td>Sewon medical</td><td>2205-006</td><td>To drain the fluid at the surgical site</td></tr><tr><td>3.0 metric absorbable suture</td><td>Ethicon</td><td>BA1673H</td><td>Muscle suture</td></tr><tr><td>2.0 metric nonabsorbable nylon suture</td><td>Ethicon</td><td>W1626T</td><td>Skin suture</td></tr><tr><td>Gauze</td><td>Kingphar Korea</td><td>KP120-06</td><td></td></tr><tr><td>Pentobarbital</td><td>Hanlim pharma</td><td>645301221</td><td>Euthanasia</td></tr><tr><td>Oscillating saw</td><td>Zimmer</td><td></td><td>Harvest spine</td></tr><tr><td>Tower forceps</td><td>Aesculap</td><td>BF461R</td><td>Harvest spine</td></tr></tbody></table>

an anesthesia, surgery, and harvest method for the evaluation of transpedicular screws using an in vivo porcine lumbar spine model

La fijación del tornillo del pedículo es el estándar de oro para el tratamiento de enfermedades espinales. Sin embargo, muchos estudios han informado de la cuestión de aflojar los tornillos pediculares después de la cirugía de la columna vertebral, que es una preocupación seria. Para abordar este problema, se han examinado diversos tipos de tornillos pediculares para identificar aquellos con buena fuerza de fijación y osteointegración en el hueso de la columna vertebral. La columna porcina es una buena alternativa para la columna vertebral humana en la evaluación de los tornillos pediculares debido al tamaño anatómico, características mecánicas y coste. Aunque varios estudios han reportado que los tornillos pediculares son eficientes en el modelo porcino, ningún estudio ha descrito protocolos detallados para la evaluación de un tornillo pedículo utilizando el modelo porcino. En este sentido, se describe un método detallado para la evaluación de tornillos transpedicular utilizando un modelo in vivo de la columna lumbar porcino. Los detalles técnicos para anestesia, cirugía de columna y cosecha proporcionados aquí facilitarán con la evaluación de la tModelo de fijación de tornillo ranspedicular.

Se describe aquí un protocolo detallado para anestesia, cirugía y cosecha para la evaluación de tornillos transpediculares utilizando un modelo de columna lumbar porcina in vivo . Este protocolo es adecuado para una serie de análisis posteriores, incluyendo pruebas mecánicas ( Figura 1 ), cuantitativos de micro-CT evaluación ( Figura 2 ], y la histología ( Figura 3 ]. Pruebas mecánicas representativas ( Figura 1<...

Watch this Scientific Journal Video about An Anesthesia, Surgery, and Harvest Method for the Evaluation of Transpedicular Screws Using an In Vivo Porcine Lumbar Spine Model at JoVE.com

An Anesthesia, Surgery, and Harvest Method for the Evaluation of Transpedicular Screws Using an In Vivo Porcine Lumbar Spine Model

Aquí, se introduce un método para evaluar los tornillos transpedicular mediante la utilización de un modelo de la columna lumbar porcino in vivo .

Anestesia, Cirugía y Método de Cosecha para la Evaluación de Tornillos Transpediculares Usando un<em&gt; In Vivo</em&gt; Modelo de columna lumbar porcina

Pedicle screw fixation is the gold standard for the treatment of spinal diseases. However, many studies have reported the issue of loosening pedicle ...

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An Anesthesia, Surgery, and Harvest Method for the Evaluation of Transpedicular Screws Using an In Vivo Porcine Lumbar Spine Model

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7.6K vistas.  Chonbuk National University School of Medicine, Chonbuk National University Hospital.  Aquí, se introduce un método para evaluar los tornillos transpedicular mediante la utilización de un modelo de la columna lumbar porcino in vivo . 

Video: An Anesthesia, Surgery, and Harvest Method for the Evaluation of Transpedicular Screws Using an In Vivo Porcine Lumbar Spine Model

In vivo Imaging of the Mouse Spinal Cord Using Two-photon Microscopy

In vivo imaging using two-photon microscopy 1 in mice that have been genetically engineered to express fluorescent proteins in specific cell types 2-3 has significantly broadened our knowledge of physiological and pathological processes in numerous tissues in vivo 4-7. In studies of the central nervous system (CNS), there has been a broad application of in vivo imaging in the brain, which has produced a plethora of novel and often unexpected findings about the behavior of cells such as neurons, astrocytes, microglia, under physiological or pathological conditions 8-17. However, mostly technical complications have limited the implementation of in vivo imaging in studies of the living mouse spinal cord. In particular, the anatomical proximity of the spinal cord to the lungs and heart generates significant movement artifact that makes imaging the living spinal cord a challenging task.
We developed a novel method that overcomes the inherent limitations of spinal cord imaging by stabilizing the spinal column, reducing respiratory-induced movements and thereby facilitating the use of two-photon microscopy to image the mouse spinal cord in vivo. This is achieved by combining a customized spinal stabilization device with a method of deep anesthesia, resulting in a significant reduction of respiratory-induced movements. This video protocol shows how to expose a small area of the living spinal cord that can be maintained under stable physiological conditions over extended periods of time by keeping tissue injury and bleeding to a minimum. Representative raw images acquired in vivo detail in high resolution the close relationship between microglia and the vasculature. A timelapse sequence shows the dynamic behavior of microglial processes in the living mouse spinal cord. Moreover, a continuous scan of the same z-frame demonstrates the outstanding stability that this method can achieve to generate stacks of images and/or timelapse movies that do not require image alignment post-acquisition. Finally, we show how this method can be used to revisit and reimage the same area of the spinal cord at later timepoints, allowing for longitudinal studies of ongoing physiological or pathological processes in vivo.

In vivo Imaging of the Mouse Spinal Cord Using Two-photon Microscopy

A minimally invasive protocol to stabilize the mouse spinal column and perform repetitive in vivo spinal cord imaging using two-photon microscopy is described. This method combines a spinal stabilization device and an anesthetic regimen to minimize respiratory-induced movements and produce raw imaging data that require no alignment or other post-processing.

Imágenes in vivo de la médula espinal de ratón Utilizando microscopía de dos fotones

In vivo imaging using two-photon microscopy 1 in mice that have been genetically engineered to express fluorescent proteins in specific cell types 2-3 has ...

Investigación

Neurociencias

A Procedure for Implanting a Spinal Chamber for Longitudinal In Vivo Imaging of the Mouse Spinal Cord

Studies in the mammalian neocortex have enabled unprecedented resolution of cortical structure, activity, and response to neurodegenerative insults by repeated, time-lapse in vivo imaging in live rodents. These studies were made possible by straightforward surgical procedures, which enabled optical access for a prolonged period of time without repeat surgical procedures. In contrast, analogous studies of the spinal cord have been previously limited to only a few imaging sessions, each of which required an invasive surgery. As previously described, we have developed a spinal chamber that enables continuous optical access for upwards of 8 weeks, preserves mechanical stability of the spinal column, is easily stabilized externally during imaging, and requires only a single surgery. Here, the design of the spinal chamber with its associated surgical implements is reviewed and the surgical procedure is demonstrated in detail. Briefly, this video will demonstrate the preparation of the surgical area and mouse for surgery, exposure of the spinal vertebra and appropriate tissue debridement, the delivery of the implant and vertebral clamping, the completion of the chamber, the removal of the delivery system, sealing of the skin, and finally, post-operative care. The procedure for chronic in vivo imaging using nonlinear microscopy will also be demonstrated. Finally, outcomes, limitations, typical variability, and a guide for troubleshooting are discussed.

A Procedure for Implanting a Spinal Chamber for Longitudinal In Vivo Imaging of the Mouse Spinal Cord

In this video, we describe a procedure for implanting a chronic optical imaging chamber over the dorsal spinal cord of a live mouse. The chamber, surgical procedure, and chronic imaging are reviewed and demonstrated.

Un procedimiento para el implante Cámara Espinal para Longitudinal<em&gt; En Vivo</em&gt; Imágenes de la médula espinal de ratón

Studies in the mammalian neocortex have enabled unprecedented resolution of cortical structure, activity, and response to neurodegenerative insults by ...

Laminotomy for Lumbar Dorsal Root Ganglion Access and Injection in Swine

Dorsal root ganglia (DRG) are anatomically well defined structures that contain all primary sensory neurons below the head. This fact makes DRG attractive targets for injection of novel therapeutics aimed at treating chronic pain. In small animal models, laminectomy has been used to facilitate DRG injection because it involves surgical removal of the vertebral bone surrounding each DRG. We demonstrate a technique for intraganglionic injection of lumbar DRG in a large animal species, namely, swine. Laminotomy is performed to allow direct access to DRG using standard neurosurgical techniques, instruments, and materials. Compared with more extensive bone removal via laminectomy, we implement laminotomy to conserve spinal anatomy while achieving sufficient DRG access. Intraoperative progress of DRG injection is monitored using a non-toxic dye. Following euthanasia on post-operative day 21, the success of injection is determined by histology for intraganglionic distribution of 4&#39;,6-diamidino-2-phenylindole (DAPI). We inject a biologically inactive solution to demonstrate the protocol. This method could be applied in future preclinical studies to target therapeutic solutions to DRG. Our methodology should facilitate testing the translatability of intraganglionic small animal paradigms in a large animal species. Additionally, this protocol may serve as a key resource for those planning preclinical studies of DRG injection in swine.

We describe a method for laminotomy in swine that provides access to lumbar dorsal root ganglia (DRG) for intraganglionic injection. Injection progress is monitored intraoperatively and histologically confirmed up to 21 days after surgery. This protocol could be used for future preclinical studies involving DRG injection.

Laminotomía para acceso de ganglio de raíz Dorsal Lumbar y de la inyección en los cerdos

Dorsal root ganglia (DRG) are anatomically well defined structures that contain all primary sensory neurons below the head. This fact makes DRG attractive ...

Laminectomy and Spinal Cord Window Implantation in the Mouse

This protocol describes a method for spinal cord laminectomy and glass window implantation for in vivo imaging of the mouse spinal cord. An integrated digital vaporizer is utilized to achieve a stable plane of anesthesia at a low-flow rate of isoflurane. A single vertebral spine is removed, and a commercially available cover-glass is overlaid on a thin agarose bed. A 3D-printed plastic backplate is then affixed to the adjacent vertebral spines using tissue adhesive and dental cement. A stabilization platform is used to reduce motion artifact from respiration and heartbeat. This rapid and clamp-free method is well-suited for acute multi-photon fluorescence microscopy. Representative data are included for an application of this technique to two-photon microscopy of the spinal cord vasculature in transgenic mice expressing eGFP:Claudin-5 &#8212; a tight junction protein.

This protocol describes implantation of a glass window onto the spinal cord of a mouse to facilitate visualization by intravital microscopy.

Laminectomía e implantación de la ventana de la médula espinal en el ratón

This protocol describes a method for spinal cord laminectomy and glass window implantation for in vivo imaging of the mouse spinal cord. An integrated ...

In Vivo Mouse Model of Spinal Implant Infection

Spine implant infections portend poor outcomes as diagnosis is challenging and surgical eradication is at odds with mechanical spinal stability. The purpose of this method is to describe a novel mouse model of spinal implant infection (SII) that was created to provide an inexpensive, rapid, and accurate in vivo tool to test potential therapeutics and treatment strategies for spinal implant infections.
In this method, we present a model of posterior-approach spinal surgery in which a stainless-steel k-wire is transfixed into the L4 spinous process of 12-week old C57BL/6J wild-type mice and inoculated with 1 x 103 CFU of a bioluminescent strain of Staphylococcus aureus Xen36 bacteria. Mice are then longitudinally imaged for bioluminescence in vivo on post-operative days 0, 1, 3, 5, 7, 10, 14, 18, 21, 25, 28, and 35. Bioluminescence imaging (BLI) signals from a standardized field of view are quantified to measure in vivo bacterial burden.
To quantify bacteria adhering to implants and peri-implant tissue, mice are euthanized and the implant and surrounding soft tissue are harvested. Bacteria are detached from the implant by sonication, cultured overnight and then colony forming units (CFUs) are counted. The results acquired from this method include longitudinal bacterial counts as measured by in vivo S. aureus bioluminescence (mean maximum flux) and CFU counts following euthanasia.
While prior animal models of instrumented spine infection have involved invasive, ex vivo tissue analysis, the mouse model of SII presented in this paper leverages noninvasive, real time in vivo optical imaging of bioluminescent bacteria to replace static tissue study. Applications of the model are broad and may include utilizing alternative bioluminescent bacterial strains, incorporating other types of genetically engineered mice to contemporaneously study host immune response, and evaluating current or investigating new diagnostic and therapeutic modalities such as antibiotics or implant coatings.

The protocol describes a novel in vivo mouse model of spinal implant infection where a stainless-steel k-wire implant is infected with bioluminescent Staphylococcus aureus Xen36. Bacterial burden is monitored longitudinally with bioluminescent imaging and confirmed with colony forming unit counts after euthanasia.

Modelo de ratón in vivo de infección por implante espinal

Spine implant infections portend poor outcomes as diagnosis is challenging and surgical eradication is at odds with mechanical spinal stability. The ...

Medicina

Real-Time Assessment of Spinal Cord Microperfusion in a Porcine Model of Ischemia/Reperfusion

Spinal cord injury is a devastating complication of aortic repair. Despite developments for the prevention and treatment of spinal cord injury, its incidence is still considerably high and therefore, influences patient outcome. Microcirculation plays a key role in tissue perfusion and oxygen supply and is often dissociated from macrohemodynamics. Thus, direct evaluation of spinal cord microcirculation is essential for the development of microcirculation-targeted therapies and the evaluation of existing approaches in regard to spinal cord microcirculation. However, most of the methods do not provide real-time assessment of spinal cord microcirculation. The aim of this study is to describe a standardized protocol for real-time spinal cord microcirculatory evaluation using laser-Doppler needle probes directly inserted in the spinal cord. We used a porcine model of ischemia/reperfusion to induce deterioration of the spinal cord microcirculation. In addition, a fluorescent microsphere injection technique was used. Initially, animals were anesthetized and mechanically ventilated. Thereafter, laser-Doppler needle probe insertion was performed, followed by the placement of cerebrospinal fluid drainage. A median sternotomy was performed for exposure of the descending aorta to perform aortic cross-clamping. Ischemia/reperfusion was induced by supra-celiac aortic cross-clamping for a total of 48 min, followed by reperfusion and hemodynamic stabilization. Laser-Doppler Flux was performed in parallel with macrohemodynamic evaluation. In addition, automated cerebrospinal fluid drainage was used to maintain a stable cerebrospinal pressure. After completion of the protocol, animals were sacrificed, and the spinal cord was harvested for histopathological and microsphere analysis. The protocol reveals the feasibility of spinal cord microperfusion measurements using laser-Doppler probes and shows a marked decrease during ischemia as well as recovery after reperfusion. Results showed comparable behavior to fluorescent microsphere evaluation. In conclusion, this new protocol might provide a useful large animal model for future studies using real-time spinal cord microperfusion assessment in ischemia/reperfusion conditions.

Spinal cord microcirculation plays a pivotal role in spinal cord injury. Most methods do not allow real-time assessment of spinal cord microcirculation, which is essential for the development of microcirculation-targeted therapies. Here, we propose a protocol using Laser-Doppler-Flow Needle probes in a large animal model of ischemia/reperfusion.

Evaluación en tiempo real de la microperfusión de la médula espinal en un modelo porcino de isquemia/reperfusión

Spinal cord injury is a devastating complication of aortic repair. Despite developments for the prevention and treatment of spinal cord injury, its ...

Surgical Technique for Lumbar Spinal Catheter Insertion in Pigs Enabling Continuous Access to the Thecal Sac in a Terminal Setup

Pigs are increasingly used as a large animal model for pharmacologic CNS research due to the anatomical and physiological similarities between the porcine and human central nervous systems (CNS). However, accessing the cerebrospinal fluid (CSF) in larger pig breeds by conventional lumbar puncture techniques can be challenging due to an oblique orientation of the spinal spinous processes and a limited interlaminar space. Accordingly, an open surgical procedure for inserting a lumbar spinal catheter for continuous CSF sampling at the L4/L5 level in pigs is thoroughly described in this work. After positioning the pig and identifying the anatomical landmarks, a dorsal midline surgical incision is made to expose the spinous processes. By advancing the introducer needle, the spinal catheter is inserted inside the thecal sac of the spinal canal while leaving the bone structures of the spine intact. This method allows continuous infusion into or sampling from the porcine thecal sac with minimal bleeding or CSF leakage. The procedure is simple, time-efficient, and reproducible across different experimental setups, offering significant potential for various pre-clinical studies, including pharmacokinetic research, surgical training, and spinal cord injury models.

We present a technique for inserting a lumbar spinal catheter at the L4-L5 level in a 3-month-old Danish Landrace pig as part of a terminal research protocol, enabling continuous infusion or CSF sampling from the thecal sac.

Técnica quirúrgica para la inserción de catéter espinal lumbar en cerdos que permite el acceso continuo al saco tecal en una configuración terminal

Pigs are increasingly used as a large animal model for pharmacologic CNS research due to the anatomical and physiological similarities between the porcine ...

A Mouse Model of Lumbar Spine Instability

Intervertebral disc degeneration (IDD) is a common pathological change leading to low back pain. Appropriate animal models are desired for understanding the pathological processes and evaluating new drugs. Here, we introduced a surgically induced lumbar spine instability (LSI) mouse model that develops IDD starting from 1 week post operation. In detail, the mouse under anesthesia was operated by low back skin incision, L3&#8211;L5 spinous processes exposure, detachment of paraspinous muscles, resection of processes and ligaments, and skin closure. L4&#8211;L5 IVDs were chosen for the observation. The LSI model develops lumbar IDD by porosity and hypertrophy in endplates at an early stage, decrease in intervertebral disc volume, shrinkage in nucleus pulposus at an intermediate stage, and bone loss in lumbar vertebrae (L5) at a later stage. The LSI mouse model has the advantages of strong operability, no requirement of special equipment, reproducibility, inexpensive, and relatively short period of IDD development. However, LSI operation is still a trauma that causes inflammation within the first week post operation. Thus, this animal model is suitable for study of lumbar IDD.

We developed a lumbar intervertebral disc degeneration mouse model by resection of L3&#8211;L5 spinous processes along with supra- and inter-spinous ligaments and detachment of paraspinous muscles.

Un modelo de ratón de inestabilidad lumbar de la columna vertebral

Intervertebral disc degeneration (IDD) is a common pathological change leading to low back pain. Appropriate animal models are desired for understanding ...

Biología

Pedicle Screw Placement Using an Augmented Reality Head-Mounted Display in a Porcine Model

This protocol helps assess the accuracy and workflow of an augmented reality (AR) hybrid navigation system using the Magic Leap head-mounted display (HMD) for minimally invasive pedicle screw placement. The cadaveric porcine specimens were placed on a surgical table and draped with sterile covers. The levels of interest were identified using fluoroscopy, and a dynamic reference frame was attached to the spinous process of a vertebra in the region of interest. Cone beam computerized tomography (CBCT) was performed, and a 3D rendering was automatically generated, which was used for the subsequent planning of the pedicle screw placements. Each surgeon was fitted with an HMD that was individually eye-calibrated and connected to the spinal navigation system.
Navigated instruments, tracked by the navigation system and displayed in 2D and 3D in the HMD, were used for 33 pedicle cannulations, each with a diameter of 4.5 mm. Postprocedural CBCT scans were assessed by an independent reviewer to measure the technical (deviation from the planned path) and clinical (Gertzbein grade) accuracy of each cannulation. The navigation time for each cannulation was measured. The technical accuracy was 1.0 mm &#177; 0.5 mm at the entry point and 0.8 mm &#177; 0.1 mm at the target. The angular deviation was 1.5&#176; &#177; 0.6&#176;, and the mean insertion time per cannulation was 141 s &#177; 71 s. The clinical accuracy was 100% according to the Gertzbein grading scale (32 grade 0; 1 grade 1). When used for minimally invasive pedicle cannulations in a porcine model, submillimeter technical accuracy and 100% clinical accuracy could be achieved with this protocol.

The augmented reality head-mounted display, Magic Leap, was used in combination with a conventional navigation system to place pedicle screws in a porcine model by adhering to a novel workflow. With a median insertion time of &lt;2.5 min, submillimeter technical accuracy and 100% clinical accuracy were achieved according to Gertzbein.

Colocación de tornillos pediculares mediante una pantalla de realidad aumentada montada en la cabeza en un modelo porcino

This protocol helps assess the accuracy and workflow of an augmented reality (AR) hybrid navigation system using the Magic Leap head-mounted display (HMD) ...

Laser Doppler Needle Probe Insertion: A Technique for Real-time Quantification of Blood Flow within the Spinal Cord in a Porcine Model

Source: Behem, C. R. et al., <a href="https://www.jove.com/v/62047">Real-Time Assessment of Spinal Cord Microperfusion in a Porcine Model of Ischemia/Reperfusion.</a> J. Vis. Exp. (2020).
This video demonstrates the placement of a laser Doppler needle probe in the spinal cord of a porcine model. This helps in the continuous quantification of blood supply to the spinal cord, an important assessment in spinal cord injury.

Inserción de sonda de aguja Doppler láser: una técnica para la cuantificación en tiempo real del flujo sanguíneo dentro de la médula espinal en un modelo porcino

Source: Behem, C. R. et al., Real-Time Assessment of Spinal Cord Microperfusion in a Porcine Model of Ischemia/Reperfusion. J. Vis. Exp. (2020).
This ...

Anestesia, Cirugía y Método de Cosecha para la Evaluación de Tornillos Transpediculares Usando un

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