Name: a rat model of mild intrauterine hypoperfusion with microcoil stenosis
Uploaded: 2018-01-07T14:00:00.000+00:00
Duration: 6 min 19 s
Description: Watch this Scientific Journal Video about A Rat Model of Mild Intrauterine Hypoperfusion with Microcoil Stenosis at JoVE.com

Questo lavoro è stato supportato dal programma di scambio FY 2013 ricerca tra JSP e CNRS, JSP KAKENHI Grant numero 26860858 e la Narishige Neuroscience Research Foundation. Ringraziamo la d. ssa Mariko Harada-Shiba e Kyoko Shioya per utili discussioni. Ringraziamo Mari Furuta, Mutsumi Sakamoto, Ritsuko Maki e Dr. Emi Tanaka per l'eccellente assistenza tecnica.

Tutti gli esperimenti sono stati eseguiti secondo protocolli approvati dal comitato di uso della nazionale cerebrale e centro cardiovascolare, Suita, Giappone e cura degli animali sperimentali.
1. preparare i seguenti animali e materiali per la chirurgia MIUH
<ol><li>Preparare temporizzati ratti Sprague-Dawley incinti al giorno gestazionale 17, vale a dire, embrionale giorno 17 (E17). Medio peso corporei del dams sono ± 307.0 40,7 g (media ± DS, n = 9).</li>
	<li>Preparare i microcoils metallici; diametro interno 0,24 mm, in acciaio rivestito in oro.</li>
	<li>Preparare tutti i materiali secondo la tabella dei materiali.</li>
</ol>2. prepararsi all'intervento MIUH
<ol><li>Scaldare una piastra a 37 ° C per il posizionamento di ratto</li>
	<li>Collocare un pannolino sterile sul tappetino di riscaldamento</li>
	<li>Soluzione salina sterile calda a 37 ° C in un bagno d'acqua</li>
</ol>3. eseguire un intervento chirurgico MIUH
<ol><li>Eseguire le procedure chirurgiche in condizioni sterili. Sterilizzare le bobine, pinze, aghi con etanolo al 70% prima dell'uso. Utilizzare guanti sterili e occasionalmente disinfettare applicando spray di etanolo.</li>
	<li>Posizionare il ratto nella casella di induzione di anestesia. Introdurre 4% isoflurane nella casella (circa 5 min).</li>
	<li>Collocare il topo su un pannolino sterile sul tappetino di riscaldamento in posizione supina dopo che l'animale è anestetizzato accuratamente nella finestra di induzione. Verifica per la profondità dell'anestesia dalla mancanza di una risposta a un pizzico di punta. Mantenere isoflurane 1.5-2.0% con un cono di naso.</li>
	<li>Applicare schiuma depilatoria sul addome dall'ombelico verso la regione dell'arco pelvica. Dopo alcuni minuti, togliere la schiuma depilatoria con un tovagliolo di carta. Un rasoio può essere usato come un sostituto per la schiuma depilatoria.</li>
	<li>Applicare una garza imbevuta di soluzione disinfettante iodio nella regione Depilata della pelle.</li>
	<li>Posizionare un telo chirurgico con un'apertura circolare per coprire l'addome, tranne l'area dell'incisione chirurgica. Diversi pezzi di garza possono essere usati come un sostituto per il drappeggio.</li>
	<li>Usando un bisturi chirurgico, fare un'incisione di circa 2,5 cm lungo il basso addome dal bordo superiore del pube verso l'alto verso l'ombelico. Quindi, fare un'incisione attraverso lo strato muscolare sottostante.</li>
	<li>Posto diversi pezzi di garza sterile intorno all'apertura del drappo e bagnare la garza con soluzione salina riscaldata.</li>
	<li>Spingere delicatamente, entrambi i lati laterali dell'addome in modo che una parte del corno uterino emerge dall'incisione.</li>
	<li>Disinfettare le mani del chirurgo con etanolo al 70%.</li>
	<li>Tirare delicatamente l'intero corno uterino dalla cavità addominale manualmente senza usare il forcipe. Usando il forcipe chirurgico non è consigliabile, come possono facilmente danneggiare utero fragile, feti e vasi sanguigni comprimendo loro fortemente e in modo non uniforme.</li>
	<li>Posto il corno uterino su garza umida.</li>
	<li>Eseguire la stessa procedura per l'altro corno uterino.</li>
	<li>Contare il numero di feti.</li>
	<li>Applicare la soluzione salina riscaldata frequentemente per mantenere l'utero caldo e umido durante tutto l'intervento chirurgico.<ol>
<li>Cambiare il pannolino quando ha assorbito troppo salino. Per mantenere la stabilità, ripetere guanti di disinfezione con etanolo al 70% e punte dello strumento con iodio. Mantenere le dita non sterili lontano le punte sterili dello strumento è cruciale.</li>
	</ol>
</li>
	<li>Identificare la parte prossimale del portico principale delle arterie ovariche ed uterine sotto un microscopio stereoscopico. Nota: È fondamentale distinguere la galleria principale dai rami per le placente. Si noti che l'intervento chirurgico può essere più facile quando il corno uterino è capovolto. Occasionalmente, l'applicazione di una bobina alla parte molto prossimale del porticato è difficile, perché si trova in profondità all'interno della cavità addominale e le arterie alla placenta sono molto vicino alla parte prossimale del arcade. In questo caso, una bobina può essere applicata ad una parte della galleria dopo il prime forcelle di ramo fuori.</li>
	<li>Dividere l'arteria dalla vena che corre parallelo ad esso con una pinza e lo spazio tra di loro.</li>
	<li>Posizionare un pezzo di spago (sutura seta 4.0, 5 cm di lunghezza) sotto l'arteria.</li>
	<li>Sollevare in entrambe le estremità della stringa con una pinza in modo che l'arteria è sollevato e separato dalla vena fragile.</li>
	<li>Tenendo il bordo del microcoil con una pinzetta in altra mano, posizionare un microcoil accanto all'arteria sollevato (Figura 2.1).</li>
	<li>Ruotare l'arteria sollevato utilizzando la stringa intorno alla microcoil per avvolgere il microcoil intorno all'arteria. È più facile ruotare l'arteria intorno alla bobina rispetto al ruotare la bobina intorno all'arteria (Figura 2.2).</li>
	<li>Dopo aver ruotato l'arteria 3 o 4 giri (bobine hanno 5 giri), modificare il sito a cui la bobina è tenuta per l'altro bordo. Tenere premuto il bordo della bobina che è stato avvolto intorno all'arteria con il forcipe. Modificare il sito in cui la stringa solleva l'arteria verso l'altro lato della bobina. Ruotare l'arteria intorno alla bobina affinché la bobina completamente (5 turni) avvolge l'arteria (Figura 2,3, 2.4).</li>
	<li>Rimuovere la stringa.</li>
	<li>Eseguire la stessa procedura per le altre tre arterie.</li>
	<li>Nota che frequentemente l'applicazione riscaldato soluzione fisiologica nell'utero è fondamentale; in caso contrario, aumenta il tasso di mortalità dei feti e ipotermia potrebbe essere neuroprotective.</li>
	<li>Delicatamente e restituire il corno uterino nella cavità addominale. Sollevamento di un bordo dell'incisione della parete addominale con il forcipe può rendere più facile questa procedura.</li>
	<li>Stich il muscolo addominale e quindi stich la pelle dell'addome con sutura (sutura seta 4.0). Legare la sutura dopo ogni stich, cioè interrotte suture singole.</li>
	<li>Applicare una garza imbevuta di soluzione disinfettante iodio su e attorno all'incisione chirurgica.</li>
	<li>Somministrare per via sottocutanea il meloxicam analgesico a 0,5 mg/kg di peso corporeo.</li>
	<li>Consentire per 30 min di recupero in una gabbia riscaldata. Controllare gli animali se completamente sveglio e in movimento intorno alla gabbia, tornare alla gabbia a casa.</li>
</ol>

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Microcoil stenosi delle arterie sia ovariche che uterine in entrambi i corni uterini produce ipoperfusione intrauterina coerente e riproducibile in tutte le placente e feti. Il livello dell'ipoperfusione può essere modificato utilizzando i microcoils con diversi diametri interni. Cuccioli del ratto, nati da una diga su cui è stata eseguita la stenosi dell'arteria con i microcoils 0,24 mm di diametro interno dimostrano IUGR e parto prematuro (Vedi riferimento 1 per i dettagli). I cuccioli presentano alterazioni neuroana...

Gli infanti con restrizione della crescita intrauterina (IUGR) (noto anche come ritardo di crescita intrauterino) (peso nascita < 10th percentile per l'età gestazionale), nascita pretermine (Nato a < 37 settimane di gestazione), e/o bassa nascita conto peso (< 2500 g) per quasi il 10% di tutti i neonati 2,3. Molti di questi infanti presentano problemi neurologici quali paralisi cerebrale e disturbi dello sviluppo (ad es., attention-deficit/hyperactivity disorder (ADHD) e disturbi dell'apprendimento) 3,4,5. Tali condizioni sono somiglianze e differenze nella loro eziologia ed i risultati. L'eziologia di IUGR è multifattoriale e insufficienza placentare associato ipoperfusione intrauterina è considerato la causa più comune in feti non anomala 7. L'eziologia del pretermine è multifattoriale pure e chorioamnionitis è la più frequente causa di 8.
L'influenza di lieve ipoperfusione intrauterina (MIUH) su sviluppo del cervello è poco chiaro. Attualmente disponibili modelli animali di ipoperfusione/ischemia intrauterina comportano principalmente hypoperfusion severo o grado di pendenza dell'ipoperfusione con o senza riperfusione 9,10,11. In ambito clinico, tuttavia, casi di MIUH sono considerati di essere molto più frequenti rispetto a quelli che coinvolgono tali condizioni gravi. I modelli attualmente disponibili di MIUH sono un modello del roditore che coinvolgono la legatura del suturare dell'uterina o dell'arteria ovarica e un modello del roditore che coinvolge le arterie ovariche bilaterali e l'aorta avendo la pervietà 12,13, di ritaglio 14,15,16,17. Uno degli svantaggi di questi modelli è la notevole variabilità inter-feto, che vanno da feti con profonda ipoperfusione a feti con aspersione quasi intatto, a seconda della posizione del feto all'interno quadriloggiato arteriosa dell'uterina e arterie ovariche. Un altro svantaggio di questi modelli è la loro incapacità di distinguere la posizione di ogni feto dopo la nascita; quindi, i ricercatori non possono distinguere la gravità dell'ipoperfusione intrauterina sperimentato da un pup individuali dopo la sua nascita.
Abbiamo sviluppato un modello del ratto di MIUH che coinvolge più di stenosi dell'arteria 1. Avvolgimento micro-bobine di metallo con un diametro interno di 0,24 mm attorno le arterie ovariche e uterine causa stenosi, ma non ostruzione dei vasi sanguigni (Figura 1). Applicando questi microcoils presso le parti prossimali di tutti delle arterie che assicurano l'utero, vale a dire, le arterie uterine ed ovariche bilaterali, il giorno embrionale 17 (equivalente a embrionali settimane 20-25 in esseri umani 18) induce una diminuzione significativa ma mite flusso di sangue alla placenta e feti. Le diminuzioni nel flusso sanguigno dopo bobine vengono applicate a tutte le quattro arterie che alimentano l'utero sono in gran parte le stesse attraverso ogni placenta ed il feto. Il tasso di mortalità del feto è meno del 20%. I cuccioli sono nati via travaglio spontaneo 1-2 giorni precedenti (embrionale giorno 21-22) rispetto al normale. Quasi tutti i cuccioli sono nati espositrici nascita significativamente bassi pesi 1. Volumi di materia grigia e bianca sono diminuiti senza danni evidente tessuto 1. I cuccioli si presentano con ritardo nella acquisizione della neonato riflessi, debolezza muscolare e alterata attività spontanea 1. Questo modello imita i segni clinici ed i sintomi dei bambini nati prematuramente o con IUGR; espositivo prematuri nati bambini ridotto grigio e volume di materia bianca con o senza materia bianca lesioni 6, presenti le pietre miliari dello sviluppo neurologico in ritardo e può presentare problemi comportamentali come ADHD 3,5; i bambini con IUGR presentano alterazioni neuroanatomiche minime e hanno un rischio aumentato di sviluppo neurologico alterato ad esempio ritardo motorio e cognitivo 4,7. Nascita pretermine e IUGR sono condizioni diverse, ma le due condizioni condividono il meccanismo di base, cioè gli insulti ai cervelli immaturi prima età gestazionale pieno-termine.

<table><tbody><tr><td>Stereomicroscope</td><td></td><td></td><td></td></tr><tr><td>Isoflurane anesthesia machine</td><td></td><td></td><td></td></tr><tr><td>Anesthesia induction box</td><td></td><td></td><td></td></tr><tr><td>Heating pad</td><td></td><td></td><td></td></tr><tr><td>Diaper 30x40 cm</td><td></td><td></td><td></td></tr><tr><td>Depilatory foam or shaver</td><td></td><td></td><td></td></tr><tr><td>Iodine disinfectant solution</td><td></td><td></td><td></td></tr><tr><td>Gauze 10x20 cm&amp;nbsp;</td><td></td><td></td><td></td></tr><tr><td>Surgical drape 45x45 cm with a round opening 5 cm in diameter</td><td></td><td></td><td></td></tr><tr><td>Spray bottle with ethanol for disinfection</td><td></td><td></td><td></td></tr><tr><td>Cotton swab</td><td></td><td></td><td></td></tr><tr><td>Forceps with large blunt tips</td><td></td><td></td><td></td></tr><tr><td>Forceps with angled fine tips</td><td></td><td></td><td></td></tr><tr><td>Scissors</td><td></td><td></td><td></td></tr><tr><td>Surgical scalpel, blade size is 27mm long (no.10, Axel, AS ONE Corporation, Osaka, Japan)</td><td></td><td></td><td></td></tr><tr><td>Surgical suture needle</td><td></td><td></td><td></td></tr><tr><td>Metal microcoils; inner diameter 0.24 mm, made from gold-coated steel (SAMINI Co. Ltd., Shizuoka, Japan)</td><td></td><td></td><td></td></tr><tr><td>Silk suture 4-0</td><td></td><td></td><td></td></tr><tr><td>Sterile saline (0.9% sodium chloride)</td><td></td><td></td><td></td></tr><tr><td>Heating water bath</td><td></td><td></td><td></td></tr><tr><td>Plastic syringes (50ml) and needles (18G)</td><td></td><td></td><td></td></tr></tbody></table>

a rat model of mild intrauterine hypoperfusion with microcoil stenosis

Ipoperfusione/ischemia intrauterina è una delle principali cause di restrizione della crescita intrauterina/fetale, parto prematuro e basso peso alla nascita. Maggior parte degli studi di questo fenomeno sono stata effettuata in entrambi modelli con ischemia intrauterina severa o con grado di pendenza dell'ipoperfusione intrauterina. Nessuno studio è stato condotto in un modello su uniforme lieve ipoperfusione intrauterina (MIUH). Due modelli sono stati utilizzati per gli studi di MIUH: un modello basato sulla legatura del suturare di entrambi i lati del porticato arterioso formata con le arterie uterine ed ovariche, e un modello transitorio basato sul ritaglio l'arterie ovariche bilaterali e l'aorta con l'evidenza. Quei due modelli del roditore di MIUH hanno alcune limitazioni, ad esempio, non tutti i feti sono sottoposti a MIUH, a seconda della loro posizione nel corno uterino. Nel nostro modello MIUH, tutti i feti sono sottoposti ad un livello paragonabile di ipoperfusione intrauterina. MIUH è stato realizzato da stenosi delicata di tutte le quattro arterie d'alimentazione dell'utero, cioè, arterie uterine ed ovariche bilaterali.
Stenosi arteriosa è stata indotta da metallo microcoils avvolto intorno le arterie d'alimentazione. Produzione di stenosi arteriosa con i microcoils ci ha permessi di controllare, ottimizzare e riprodurre la diminuzione del flusso sanguigno con pochissima variabilità e un tasso di mortalità basso, consentendo in tal modo una valutazione accurata. Quando si usavano i microcoils con un diametro interno di 0,24 mm, il flusso di sangue nella placenta e feto era leggermente diminuita (circa 30% dal livello pre-stenosi nella placenta). La prole del nostro modello MIUH dimostra chiaramente di lunga durata alterazioni nei risultati del test neurologici, neuroanatomical e comportamentali.

Dopo aver applicato i microcoils a tutti delle arterie che alimentano l'utero, vale a dire, le arterie uterine ed ovariche bilaterali, tutti i feti sono sottoposti a livelli comparabili di ipoperfusione. L'applicazione di microcoils con un diametro interno di 0,24 mm provoca lieve stenosi di quelle arterie, causando così una lieve diminuzione nel flusso di sangue alla placenta e feti (Figura 3; circa il 30% dal livello pre-stenosi nella placenta, vedere rife...

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A Rat Model of Mild Intrauterine Hypoperfusion with Microcoil Stenosis

Lieve ipoperfusione intrauterino è stato prodotto da stenosi dell'arteria con i microcoils metallici avvolti intorno le arterie uterine ed ovariche in ratti al giorno embrionale 17. Questa procedura ha prodotto prenatale ipoperfusione e restrizione della crescita intrauterina.

Un modello del ratto dell'ipoperfusione lieve intrauterina con stenosi Microcoil

Intrauterine hypoperfusion/ischemia is one of the major causes of intrauterine/fetal growth restriction, preterm birth, and low birth weight. Most studies ...

a-rat-model-of-mild-intrauterine-hypoperfusion-with-microcoil-stenosis

Research

JoVE Journal

Neuroscience

10.2K Views.  National Cerebral and Cardiovascular Center. Lieve ipoperfusione intrauterino è stato prodotto da stenosi dell'arteria con i microcoils metallici avvolti intorno le arterie uterine ed ovariche in ratti al giorno embrionale 17. Questa procedura ha prodotto prenatale ipoperfusione e restrizione della crescita intrauterina.

Video: A Rat Model of Mild Intrauterine Hypoperfusion with Microcoil Stenosis

The Hypoxic Ischemic Encephalopathy Model of Perinatal Ischemia

Hypoxic-Ischemic Encephalopathy (HIE) is the consequence of systemic asphyxia occurring at birth. Twenty five percent of neonates with HIE develop severe and permanent neuropsychological sequelae, including mental retardation, cerebral palsy, and epilepsy. The outcomes of HIE are devastating and permanent, making it critical to identify and develop therapeutic strategies to reduce brain injury in newborns with HIE. To that end, the neonatal rat model for hypoxic-ischemic brain injury has been developed to model this human condition. The HIE model was first validated by Vannucci et al 1 and has since been extensively used to identify mechanisms of brain injury resulting from perinatal hypoxia-ischemia 2 and to test potential therapeutic interventions 3,4. The HIE model is a two step process and involves the ligation of the left common carotid artery followed by exposure to a hypoxic environment. Cerebral blood flow (CBF) in the hemisphere ipsilateral to the ligated carotid artery does not decrease because of the collateral blood flow via the circle of Willis; however with lower oxygen tension, the CBF in the ipsilateral hemisphere decreases significantly and results in unilateral ischemic injury. The use of 2,3,5-triphenyltetrazolium chloride (TTC) to stain and identify ischemic brain tissue was originally developed for adult models of rodent cerebral ischemia 5, and is used to evaluate the extent of cerebral infarctin at early time points up to 72 hours after the ischemic event 6. In this video, we demonstrate the hypoxic-ischemic injury model in postnatal rat brain and the evaluation of the infarct size using TTC staining.

The postnatal rat model for hypoxic-ischemic brain injury is a well-established model of human neonatal hypoxic ischemic encephalopathy (HIE). In this article, we describe the model of HIE in post-natal rat pups.

Il modello di encefalopatia ipossico ischemica di ischemia perinatale

Hypoxic-Ischemic Encephalopathy (HIE) is the consequence of systemic asphyxia occurring at birth. Twenty five percent of neonates with HIE develop severe ...

Ricerca

Biologia

Fetal Echocardiography and Pulsed-wave Doppler Ultrasound in a Rabbit Model of Intrauterine Growth Restriction

Fetal intrauterine growth restriction (IUGR) results in abnormal cardiac function that is apparent antenatally due to advances in fetoplacental Doppler ultrasound and fetal echocardiography. Increasingly, these imaging modalities are being employed clinically to examine cardiac function and assess wellbeing in utero, thereby guiding timing of birth decisions. Here, we used a rabbit model of IUGR that allows analysis of cardiac function in a clinically relevant way. Using isoflurane induced anesthesia, IUGR is surgically created at gestational age day 25 by performing a laparotomy, exposing the bicornuate uterus and then ligating 40-50% of uteroplacental vessels supplying each gestational sac in a single uterine horn. The other horn in the rabbit bicornuate uterus serves as internal control fetuses. Then, after recovery at gestational age day 30 (full term), the same rabbit undergoes examination of fetal cardiac function. Anesthesia is induced with ketamine and xylazine intramuscularly, then maintained by a continuous intravenous infusion of ketamine and xylazine to minimize iatrogenic effects on fetal cardiac function. A repeat laparotomy is performed to expose each gestational sac and a microultrasound examination (VisualSonics VEVO 2100) of fetal cardiac function is performed. Placental insufficiency is evident by a raised pulsatility index or an absent or reversed end diastolic flow of the umbilical artery Doppler waveform. The ductus venosus and middle cerebral artery Doppler is then examined. Fetal echocardiography is performed by recording B mode, M mode and flow velocity waveforms in lateral and apical views. Offline calculations determine standard M-mode cardiac variables, tricuspid and mitral annular plane systolic excursion, speckle tracking and strain analysis, modified myocardial performance index and vascular flow velocity waveforms of interest. This small animal model of IUGR therefore affords examination of in utero cardiac function that is consistent with current clinical practice and is therefore useful in a translational research setting.

We describe examination of fetal cardiac function with contemporary functional fetal echocardiography and fetoplacental Doppler ultrasound using the VisualSonics VEVO 2100 microultrasound in a surgically induced model of intrauterine fetal growth restriction in a rabbit.

L&#39;ecocardiografia fetale e Pulsed-Doppler ad ultrasuoni in un modello di coniglio di ritardo di crescita intrauterino

Fetal intrauterine growth restriction (IUGR) results in abnormal cardiac function that is apparent antenatally due to advances in fetoplacental Doppler ...

Medicina

Transuterine Fetal Tracheal Occlusion Model in Mice

Fetal tracheal occlusion (TO), an established treatment modality, promotes fetal lung growth and survival in severe congenital diaphragmatic hernia (CDH). Following TO, retention of the secreted epithelial fluid increases luminal pressure and induces lung growth. Various animal models have been defined to understand the pathophysiology of CDH and TO. All have their own advantages and disadvantages such as the difficulty of the technique, the size of the animal, cost, high mortality rates, and the availability of genetic tools. Herein, a novel transuterine model of murine fetal TO is described. Pregnant mice were anesthetized, and the uterus exposed via a midline laparotomy. The trachea of selected fetuses were ligated with a single transuterine suture placed behind the trachea, one carotid artery, and one jugular vein. The dam was closed and allowed to recover. Fetuses were collected just before parturition. Lung to body weight ratio in TO fetuses was higher than that in control fetuses. This model provides researchers with a new tool to study the impact of both TO and increased luminal pressure on lung development.

Various animal models of congenital diaphragmatic hernia and fetal tracheal occlusion present advantages and disadvantages regarding ethical issues, cost, surgical difficulty, size, survival rates, and availability of genetic tools. This model provides a new tool to study the impact of both tracheal occlusion and increased luminal pressure on lung development.

Modello di occlusione tracheale fetale transuterina nei topi

Fetal tracheal occlusion (TO), an established treatment modality, promotes fetal lung growth and survival in severe congenital diaphragmatic hernia (CDH). ...

Biologia dello sviluppo

Stenosis of the Inferior Vena Cava: A Murine Model of Deep Vein Thrombosis

Deep vein thrombosis (DVT) and its devastating complication, pulmonary embolism, are a severe health problem with high mortality. Mechanisms of thrombus formation in veins remain obscure. Lack of mobility (e.g., after surgery or long-haul flights) is one of the main factors leading to DVT. The pathophysiological consequence of the lack of mobility is blood flow stagnation in venous valves. Here, a model is described that mimics such flow disturbance as a thrombosis-driving factor. In this model, partial flow restriction (stenosis) in the inferior vena cava (IVC) is created. Closure of about 90% of the IVC lumen for 48 h results in development of thrombi structurally similar to those in humans. The similarities are: i) most of the thrombus volume is red, i.e., consists of red blood cells and fibrin, ii) presence of a white part (lines of Zahn), iii) non-denuded endothelial monolayer, iv) elevated plasma D-Dimer levels, and v) possibility to prevent thrombosis by low molecular weight heparin. Limitations include variable size of thrombi and the fact that a certain percentage of wild-type mice (0 - 35%) may not produce a thrombus. In addition to visual observation and measurement, thrombi may be visualized by non-invasive technologies, such as ultrasonography, which allows for monitoring the dynamics of thrombus development. At shorter time points (1 - 6 h), intravital microscopy may be applied to directly observe events (e.g., recruitment of cells to the vessel wall) preceding thrombus formation. Use of this method by several teams around the world has made it possible to uncover basic mechanisms of DVT initiation and identify potential targets that might be beneficial for its prevention.

We describe here stenosis in the inferior vena cava as a murine model of deep vein thrombosis. This model recapitulates blood flow restriction, one of the major triggers of venous thrombosis in humans.

Stenosi della Vena Cava inferiore: un modello murino di trombosi venosa profonda

Deep vein thrombosis (DVT) and its devastating complication, pulmonary embolism, are a severe health problem with high mortality. Mechanisms of thrombus ...

Immunologia e infezioni

Transient Middle Cerebral Artery Occlusion Model of Neonatal Stroke in P10 Rats

A number of animal models have been used to study hypoxic-ischemic injury, traumatic injury, global hypoxia, or permanent ischemia in both the immature and mature brain. Stroke occurs commonly in the perinatal period in humans, and transient ischemia-reperfusion is the most common form of stroke in neonates. The reperfusion phase is a critical component of injury progression, which occurs over a period of days to weeks, and of the endogenous response to injury. This postnatal day 10 (p10) rat model of transient middle cerebral artery occlusion (tMCAO) creates a unilateral, non-hemorrhagic focal ischemia-reperfusion injury that can be utilized to study the mechanisms of focal injury and repair in the full-term-equivalent brain. The injury pattern that is produced by tMCAO is consistent and highly reproducible and can be confirmed with MRI or histological analyses. The severity of injury can be manipulated through changes in occlusion time and other methods that will be discussed.

Neonatal stroke is a significant cause of early brain injury requiring a translational model with consistent focal injury patterns and high reproducibility in order to enable study. This study describes the detailed surgical procedure for creating a non-hemorrhagic, unilateral focal ischemia-reperfusion injury in full-term-equivalent rodents.

Transient Medio occlusione dell&#39;arteria cerebrale Modello di Stroke neonatale nei ratti P10

A number of animal models have been used to study hypoxic-ischemic injury, traumatic injury, global hypoxia, or permanent ischemia in both the immature ...

Murine Model of Central Venous Stenosis using Aortocaval Fistula with an Outflow Stenosis

Central venous stenosis is an important entity contributing to arteriovenous fistula (AVF) failure. A murine AVF model was modified to create a partial ligation of the inferior vena cava (IVC) in the outflow of the fistula, mimicking central venous stenosis. Technical aspects of this model are introduced. The aorta and IVC are exposed, following an abdominal incision. The infra-renal aorta and IVC are dissected for proximal clamping, and the distal aorta is exposed for puncture. The IVC at the midpoint between the left renal vein and the aortic bifurcation is carefully dissected to place an 8-0 suture beneath the IVC. After clamping the aorta and IVC, an AVF is created by puncturing the infra-renal aorta through both walls into the IVC with a 25 G needle, followed by ligating a 22 G intra-venous (IV) catheter and IVC together. The catheter is then removed, creating a reproducible venous stenosis without occlusion. The aorta and IVC are unclamped after confirming primary hemostasis. This novel model of central vein stenosis is easy to perform, reproducible, and will facilitate studies on AVF failure.

An aortocaval fistula was created by puncturing the murine infra-renal aorta through both walls into the inferior vena cava and was followed by creation of a stenosis in its outflow via partial ligation of the inferior vena cava. This reproducible model can be used to study central venous stenosis.

Modello Murine della Stenosi Venoso Centrale utilizzando Aortocaval Fistula con una stenosi di flusso

Central venous stenosis is an important entity contributing to arteriovenous fistula (AVF) failure. A murine AVF model was modified to create a partial ...

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.

Valutazione in tempo reale della microperfusione del midollo spinale in un modello suino di ischemia/riperfusione

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

Myocardial Infarction by Percutaneous Embolization Coil Deployment in a Swine Model

Myocardial infarction (MI) is the leading cause of mortality worldwide. Despite the use of evidence-based treatments, including coronary revascularization and cardiovascular drugs, a significant proportion of patients develop pathological left-ventricular remodeling and progressive heart failure following MI. Therefore, new therapeutic options, such as cellular and gene therapies, among others, have been developed to repair and regenerate injured myocardium. In this context, animal models of MI are crucial in exploring the safety and efficacy of these experimental therapies before clinical translation. Large animal models such as swine are preferred over smaller ones due to the high similarity of swine and human hearts in terms of coronary artery anatomy, cardiac kinetics, and the post-MI healing process. Here, we aimed to describe an MI model in pig by permanent coil deployment. Briefly, it comprises a percutaneous selective coronary artery cannulation through retrograde femoral access. Following coronary angiography, the coil is deployed at the target branch under fluoroscopic guidance. Finally, complete occlusion is confirmed by repeated coronary angiography. This approach is feasible, highly reproducible, and emulates the pathogenesis of human non-revascularized MI, avoiding the traditional open-chest surgery and the subsequent postoperative inflammation. Depending on the time of follow-up, the technique is suitable for acute, sub-acute, or chronic MI models.

Myocardial infarction (MI) animal models that emulate the natural process of the disease in humans are crucial to understanding pathophysiological mechanisms and testing the safety and efficacy of new emergent therapies. Here, we describe an MI swine model created by deploying a percutaneous embolization coil.

Infarto miocardico mediante dispiegamento della bobina di embolizzazione percutanea in un modello suino

Myocardial infarction (MI) is the leading cause of mortality worldwide. Despite the use of evidence-based treatments, including coronary revascularization ...

Early Pathological and Magnetic Resonance Detection of Cerebral Injury Using a Rat Model of Neonatal Hypoxic Ischemic Encephalopathy

Perinatal hypoxic-ischemic encephalopathy (HIE) is an acute disease that may afflict newborns, resulting in variable long- and short-term neurodevelopmental outcomes. Early diagnosis is critical to identifying infants who may benefit from intervention; however, early diagnosis relies heavily on clinical criteria. No molecular or radiological tests have shown promise in detecting early cerebral injury. Studies have shown that magnetic resonance imaging (MRI) can show changes in both blood flow/ischemia and metabolic disruption. However, they have all been used to evaluate the secondary phase of the disease (&gt;12 h) after the onset of the injury. Early diagnosis is critical to rapidly starting therapeutic hypothermia in eligible infants, which is currently recommended to be initiated within 6 h of birth. The rat model of hypoxic-ischemic injury was developed in 1981 and has been validated and used extensively to study changes in brain perfusion, cerebral injury markers, and morphology. However, it has primarily been used as a "late model", evaluating injury several days after the initial ischemic insult. The model has been known to have poor sensitivity in evaluating reliable and reproducible early cerebral changes. The objective of this study was to develop a reliable model to study early gross morphological and radiological markers of HIE using pathological staining and cerebral magnetic resonance imaging/magnetic resonance spectroscopy.

The present protocol describes a rodent model of newborn hypoxic-ischemic injury for identifying early changes in cerebral tissue by gross morphology and magnetic resonance imaging. This has benefits over existing models, which can be used to study late injury but do not allow the evaluation of reproducible early changes.

Perinatal hypoxic-ischemic encephalopathy (HIE) is an acute disease that may afflict newborns, resulting in variable long- and short-term ...

Bande aortica ascendente per lo studio dell'insufficienza cardiaca indotta da sovraccarico di pressione

A Minimally Invasive Model of Aortic Stenosis in Swine

Large animal models of heart failure play an essential role in the development of new therapeutic interventions due to their size and physiological similarities to humans. Efforts have been dedicated to creating a model of pressure-overload induced heart failure, and ascending aortic banding while still supra-coronary and not a perfect mimic of aortic stenosis in humans, closely resembling the human condition.
The purpose of this study is to demonstrate a minimally invasive approach to induce left ventricular pressure overload by placing an aortic band, precisely calibrated with percutaneously introduced high-fidelity pressure sensors. This method represents a refinement of the surgical procedure (3Rs), resulting in homogenous trans-stenotic gradients and reduced intragroup variability. Additionally, it enables swift and uneventful animal recovery, leading to minimal mortality rates. Throughout the study, animals were followed for up to 2 months after surgery, employing transthoracic echocardiography and pressure-volume loop analysis. However, longer follow-up periods can be achieved if desired. This large animal model proves valuable for testing new drugs, particularly those targeting hypertrophy and the structural and functional alterations associated with left ventricular pressure overload.

Autore in primo piano: Sviluppo di un modello minimamente invasivo di grandi animali per una ricerca cardiovascolare affidabile e riproducibile 

This protocol describes a minimally invasive surgical procedure for ascending aortic banding in swine.

Un modello minimamente invasivo di stenosi aortica nei suini

Large animal models of heart failure play an essential role in the development of new therapeutic interventions due to their size and physiological ...

Un modello del ratto dell'ipoperfusione lieve intrauterina con stenosi Microcoil

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