Hypertrophic osteopathy in a common dolphin (Delphinus delphis) with concurrent pulmonary Halocercus delphini infestation.

Dolphins are marine mammals that often live in coastal habitats. Common causes of severe skeletal disorders among wild dolphins are congenital vertebral anomalities, collisions with sea vessels, trauma, hunting-related injury, infectious diseases, environmental pollution, and tumors. A free-ranging male, 3-year-old common dolphin (Delphinus delphis) was found dead in the coast of Asturias in northern Spain. Postmortem examination revealed lordosis in the caudal vertebral column, while X-ray imaging and computer tomography showed well-organized palisade-like periosteal proliferation, appearing as florid-like accretions, along the spinous apophysis of 26 lumbar-caudal vertebrae. The transverse apophysis was affected on only a few caudal vertebrae. The cortical layer remained intact. Histology of vertebra tissue showed periosteal proliferation of cancellous bone. The animal was diagnosed with hypertrophic osteopathy. The lungs showed diffuse parasitic granulomatous bronchointerstitial pneumonia caused by Halocercus delphini, consolidation of the pulmonary tissue, congestion, and alveolar edema. The animal was also afflicted by parasitic granulomatous gastritis caused by Anisakis simplex sensu lato and tattoo skin disease. The dolphin suffered from hypertrophic osteopathy associated with pulmonary Halocercus delphini infestation. This syndrome, known as hypertrophic pulmonary osteopathy, has been described in diverse terrestrial mammals, including domestic animals, wildlife and humans, but not in dolphins. This case reports the first description of hypertrophic osteopathy associated to a pulmonary disorder in dolphin, and it provides insights into factors that can induce column malformation in dolphins, suggesting the importance of taking thoracic lesions into account during differential diagnosis.

Drug prescription pattern in exotic pet and wildlife animal practice: a retrospective study in a Spanish veterinary teaching hospital from 2018 to 2022.

Exotic companion animals have had an important role in our society since ancient times. Preserving animal health is necessary to do a responsible use of veterinary medicines. This study aimed to describe the prescription patterns of drugs in exotic pets and wildlife animals attending the Veterinary Teaching Hospital of the University of León (HVULE). A retrospective study was carried out between 2018 and 2022. Birds were the largest group of exotic animals attending the HVULE. Visits were related to emergency reasons and for musculoskeletal disorders. One-third of the animals were eventually euthanised. Regarding pharmacological treatments, the most frequently active ingredients used were pentobarbital, isoflurane, meloxicam, and within antibiotics, marbofloxacin (category B in the classification of European Medicines Agency).

Arthroscopic Tenotomy of the Long Head of the Biceps Tendon and Section of the Anterior Joint Capsule Produce Moderate Osteoarthritic Changes in an Experimental Sheep Model.

Osteoarthritis (OA) of the glenohumeral (GH) joint is a common cause of shoulder pain, resulting in considerable invalidity. Unfortunately, the study of its pathogenesis is challenging. Models of OA are necessary to identify specific targets for therapy and to be able to interfere with the development and evolution of OA. This study aims to assess the effect of an arthroscopic tenotomy of the long head of the biceps tendon (LHBT) and section of the anterior glenohumeral joint capsule on the ovine glenohumeral joint. In addition, the authors aim to validate and evaluate the reliability of a modified semi-quantitative MRI score to assess joint degeneration in a sheep's shoulder. Eight skeletally mature sheep received an arthroscopic tenotomy of the LHBT and section of the anterior joint capsule and were euthanized four months after surgery. All animals tolerated the surgery well, and no complication was recorded for six weeks. Moderate degenerative changes to the ovine shoulder joint were found on MRI and histological evaluation. The arthroscopic tenotomy of the LHBT and the anterior glenohumeral joint capsule section caused moderate degenerative changes to the ovine shoulder joint.

Comparing the Effect of Different Antibiotics in Frozen-Thawed Ram Sperm: Is It Possible to Avoid Their Addition?

It is crucial to perform a deep study about the most extensively used antibiotics in sperm extenders. Most of the protocols and concentrations used in ram are direct extrapolations from other species. It is important to establish species-specific antibiotic treatments to optimize their use and if it is possible to reduce the quantity. Previews studies have assessed some aspects of sperm quality in vitro, but this study aimed to go further and assess the effect of three different antibiotic treatments, which are the most extensively used, not only in sperm quality or assessing the inhibitory effect on bacterial growth but also assessing these important parameters of productivity such as fertility, prolificacy, fecundity, and sex-ratio during a freeze-thaw process. Gentamicyn (G) treatment showed the worst results, not only concerning sperm quality but also in the reproductive trials exhibiting a toxical effect at the experiment concentration, and being the most powerful inhibiting bacterial growth. For its part, Lincomicyn-spectinomycin (LS) showed similar results inhibiting bacterial growth but it did not show a detrimental effect either in sperm quality or in reproductive parameters. Penicillin-streptomycin (PS) showed good results in the sperm quality and in the reproductive in vivo trials, but it showed a very poor effect inhibiting bacterial growth probably due to some kind of antibiotic resistance. According to our results, there is not a significant positive relationship between the higher bacterial inhibitory activity of LS and PS samples, and the sperm quality respect Control samples (without antibiotics). In the case of G, which exhibited the most effective as antibacterial, we observed a toxic effect on sperm quality that could be translated on productivity parameters. Our results suggest that the bacterial contamination control in frozen-thawed semen may be possible without the use of antibiotics, although the effects of longer periods of cooling storage and different temperatures of storage need to be further investigated for animal semen. At this point, a reflection about a drastic reduction in the use of antibiotic treatments in sperm cryopreservation is mandatory, since freezing conditions could keep sperm doses contamination within the levels recommended by regulatory health agencies.

Magnetic resonance imaging and immunohistochemistry of primary vertebral hemangiosarcoma in a dog and implications for diagnosis and therapy.

A vertebral mass in a dog with an acute onset paraparesis was identified by magnetic resonance imaging. A poorly differentiated hemangiosarcoma was diagnosed by histopathology and immunohistochemistry. Endothelial nitric oxide synthase could be a new differential marker for poorly differentiated hemangiosarcoma in dogs. Immunohistochemical detection of p53 phosphorylated at Serine392, p53, CD117, and CD44 suggest targets for design of therapeutic strategies.

Imagerie par résonance magnétique et immunistochimie d'un hémangiosarcome vertébral primaire chez un chien et répercussions pour le diagnostic et le traitement. Une masse vertébrale chez un chien atteint d'une manière soudaine d'une paraparésie a été identifiée à l'aide d'imagerie par résonance magnétique. Un hémangiosarcome mal différencié a été diagnostiqué par histopathologie et immunohistochimie. La synthase à l'oxyde nitrique endothélial pourrait être un nouveau marqueur différentiel pour l'hémangiosarcome mal différencié chez les chiens. La détection immunohistochimique de p53 phosphorylé à la sérine392, p53, CD117 et CD44 suggère des cibles pour la conception de stratégies thérapeutiques.(Traduit par Isabelle Vallières).

Surgical induced models of joint degeneration in the ovine stifle: Magnetic resonance imaging and histological assessment.

BACKGROUND: The purposes of this study were to (1) validate and assess the reliability of a modified magnetic resonance semi-quantitative score (sheep Magnetic Resonance osteoarthritis Knee Score (sMOAKS)) to evaluate joint degeneration in the ovine knee and to (2) investigate whether the transection of the anterior cruciate ligament (ACL), isolated or in combination with meniscal injuries, reproduce the degenerative changes described in the meniscectomized sheep. METHODS: Twenty sheep were randomly subjected to one of the following injuries to induce osteoarthritis (OA): ACL transection (ACLt), mid-body transection of the medial meniscus, ACLt combined with complete medial meniscectomy and complete medial meniscectomy. OA assessment was performed eight weeks postoperatively with sMOAKS, Mankin and Osteoarthritis Research Society International (OARSI) histological scores. RESULTS: sMOAKS showed very good to excellent reliability (kappa=0.61 to 1.0) for the majority of features evaluated. sMOAKS revealed small differences between groups (p<0.05) being the ACLt group the most affected. We observed a strong positive correlation between the three scales in the evaluation of femoro-tibial articular cartilage (AC) (r=0.829, r=0.917, r=0.879). CONCLUSIONS: sMOAKS is a reliable semi-quantitative Magnetic Resonance (MR) scale to evaluate and quantify the effect of different OA induction lesions in the ovine knee and presents a high correlation with Mankin and OARSI scales in the evaluation of femoro-tibial AC. Although minor differences were observed between the different surgical procedures for the induction of OA, ACLt proved to be the intervention that produced the highest amount of degeneration eight weeks postoperatively. LEVEL OF EVIDENCE: II.

Preclinical evaluation of coronary stents: focus on safety issues.

In recent years, we have witnessed a revolution in the treatment of coronary artery disease. The development and improvement of drug eluting stents (DES) have lowered the incidence of restenosis to one-digit figures. In the search for a superior efficacy, animal models have played a key role. The classical swine model of coronary stenting remains the preferred model to measure restenosis, although the rabbit iliac artery stenting has become an accepted alternative. After widespread clinical use of DES, an unforeseen complication arose: late stent thrombosis. In a back-to-bench step, some data from animal models helped to explain the phenomenon. A delayed and incomplete vascular healing was detected. Toxic and hypersensitivity reactions to polymers and/or drugs seem to be the underlying causes. So, translational research focused on the safety aspect of these devices: development of better drug carriers as absorbable polymers or fully bioresorbable scaffolds, selection of different drugs and assessment of the re-endothelialization process. We review and evaluate the efficacy and safety of coronary stents in different animal models. Further improvements in this field such as, the selection of better animal models (e.g. hyperlipidemic, diabetic, atherosclerotic) that closely mimic the clinical setting and longer follow-up periods to detect late complications are also discussed.

Anestesia en el modelo animal de investigación cardiovascular / Anesthesia in animal models used in cardiovascular research

En investigación cardiovascular se ha empleado animales pequeños y grandes y de distintas especies como modelos. La elección de la especie que se use como modelo es una de las decisiones más importantes que se ha de tomar antes del inicio de una investigación biomédica. Una elección correcta de la técnica anestésica nos proporciona una mejora de las tasas de supervivencia, así como el mayor bienestar posible de los modelos animales empleados, lo que incrementa la aceptación ética y la eficiencia de estos modelos experimentales. Esta revisión analiza las características particulares de cada modelo animal empleado en investigación cardiovascular en cuanto a las técnicas analgésicas y anestésicas, así como las técnicas, los fármacos y su posología más adecuados a cada caso (AU)

Preclinical cardiovascular research employs of a wide range of animal models, including large and small animals and a variety of species. Selecting a species for use as an animal model is one of the most important decisions that has to be taken before starting a biomedical study. The appropriate choice of anesthesia increases the survival rate and improves animal welfare, both of which increase the ethical acceptability of this kind of research and ensure that the experimental models are used as efficiently as possible. This review discusses the specific characteristics of the different animal models used in cardiovascular research from the point of view of anesthesia and analgesia and, in each case, describes the most appropriate techniques, drugs and dosages (AU)

Resonancia magnética cardiaca en modelos animales / Cardiac magnetic resonance imaging in animal models

La resonancia magnética se ha erigido en la técnica de elección para el diagnóstico y manejo de múltiples enfermedades. En el campo cardiaco permite alcanzar una precisión muy alta en la cuantificación y la caracterización tisular gracias a su elevada resolución espacial y temporal a la vez que permite una muy buena caracterización tisular. Por ello, su aplicación a la investigación traslacional resulta clave en la valoración de muchos de los resultados. En este original se revisan las aplicaciones de la técnica en distintos modelos animales, desde los más pequeños hasta el más empleado en la investigación cardiovascular traslacional, el porcino. Se analizan los distintos medios de contraste empleados y se sistematizan los estudios cardiacos para la obtención de los mejores resultados anatómicos y funcionales (AU)

Magnetic resonance imaging is now established as the gold standard for the diagnosis and management of a range of diseases. In cardiology, the technique’s high spatial and temporal resolution makes it possible to quantify and characterize anatomical structures with great precision. Consequently, it has played a key role in evaluating the results of translational research. This article contains a review of the application of magnetic resonance imaging in animal models, from the smallest species to the animal used most frequently in cardiovascular translational research - the pig. The different contrast media available are discussed, and a systematic guide to the cardiac studies that give the best anatomical and physiological results is presented (AU)

Vasomotor response to different endothelium-dependent vasodilators in an animal model.

BACKGROUND AND OBJECTIVES: Incomplete re-endothelialization of stents can be revealed as paradoxical vasoconstriction with endothelium-dependent vasodilators. As no consensus exists about the best method or agent, our objective is to analyze the response to different drugs in a coronary swine model. METHODS: Twenty-seven stents were implanted in 9 domestic swine. The vessel diameter of proximal and distal segments (≥5 mm) was assessed immediately post implantation. Different endothelium-dependent vasodilators were used: intracoronary (IC) acetylcholine, 20 µg (A2) and 40 µg (A4), IC serotonin (S), 100 µg, and isoproterenol (I), intravenous infusion. The results are presented as constriction (%) compared with maximal vasodilation with IC nitroglycerin (N, 200 µg). RESULTS: In 10 vessels (37%), A4 provoked an occlusive spasm. Acetylcholine induced a higher degree of vasoconstriction (A4, 42 ± 39%; A2, 16 ± 14%) than the rest of the agonists (S, 6 ± 12%; I, 6 ± 11%; P<.01). The constriction rate was not related to the induced hemodynamic changes. CONCLUSIONS: After focal endothelial denudation in a coronary swine model, the constriction rate induced by different endothelium-dependent vasodilators is highly variable. The highest value is observed after IC acetylcholine bolus. The constriction rate does not correlate with the observed hemodynamic changes.

Emerging topics on the hip: ligamentum teres and hip microinstability.

Microinstability and ligament teres lesions are emergent topics on the hip pathology. These entities are an increasingly recognized cause of persistent hip pain and should be considered in the differential diagnosis of the patient with hip pain. Conventional (non-arthrographic) CT and MR have a very limited role in the evaluation of these entities. CTa and MRa have emerged as the modalities of choice for pre-operative imaging of ligamentum teres injuries and microinstability. To date, pre-operative imaging detection of these pathologies is not widespread but with appropriate imaging and a high index of suspicion, preoperative detection should improve. This article discusses current concepts regarding anatomy, biomechanics, clinical findings, diagnosis and treatment of ligament teres lesions and microinstability.

Anatomic and radiographic evaluation of the hip.

The hip is a challenging joint to study is deeply located in the pelvis and surrounding by a large group of muscles with complex tendinous attachments. Our knowledge has recently increased together with the advent of new surgical techniques but further research is needed to better understand hip biomechanics and the relevance of some of radiological findings. Although recent techniques such as MR show anatomy exquisitely is essential to start with pelvis plain radiography for a good evaluation of bone structures and pelvis alignment. During this chapter we will be give a short overview of pelvis normal structures and some key points of MR and MR arthrography technique, because more detailed description is done on every specific chapter.

La reestenosis en el stent depende del daño vascular inducido. ¿Son válidos los modelos experimentales actuales de análisis de los stents farmacoactivos? / Instent restenosis related to vessel injury score degree. Are current experimental models valid for drug-eluting stents analysis?

Introducción y objetivos. Los stents farmacoactivos son una herramienta útil para prevenir la reestenosis, pero los mecanismos involucrados en la respuesta proliferativa tras su implante aún no son conocidos en su totalidad. El objetivo de este estudio es comparar la histomorfometría vascular coronaria tras el implante de stents sin recubrir o stents farmacoactivos en un modelo porcino. Métodos. En 20 hembras de cerdos de la raza Large White de 2 meses de edad se implantó de forma aleatoria un total de 60 stents distribuidos en dos grupos: convencionales (n=20) y farmacoactivos (paclitaxel) (n=40). A los 28 días se procedió a eutanasia y análisis histomorfométrico. Se clasificó el grado de daño vascular en función de integridad o rotura de la túnica limitante elástica interna. Resultados. En el grupo de integridad de lámina elástica interna no se encontraron diferencias significativas entre stents farmacoactivos y stents convencionales para las variables área de neoíntima y porcentaje de reestenosis (1,3 [1,1-2,2] frente a 2 [1,3-2,5] mm2; p=0,6; y 14 [12,1-20,8] frente a 22,2 [14,1-23,3] %; p=0,5). En cambio, en el grupo de rotura de la lámina elástica interna sí se encontraron diferencias significativas (área de neoíntima, 1,2 [0,8-2] frente a 2,9 [2,3-3,7] mm2; p=0,001 y porcentaje de reestenosis, 16,63 [11,2-23,5] frente a 30,4 [26,4-45,7] %; p=0,001). Conclusiones. En el modelo porcino de coronarias sanas, la integridad de la lámina elástica interna no permite apreciar diferencias en la respuesta proliferativa entre stent farmacoactivo y convencional; la diferencia se establece sólo cuando el daño vascular es más profundo (AU)

Introduction and objectives. Drug-eluting stents are useful for preventing restenosis, but the patho-physiological processes involved in the proliferative response after implantation are still not known in detail. The aim of this study is to compare the coronary vascular histomorphometry after implanting drug-eluting stents and bare metal stents in a swine model. Methods. Sixty stents were randomly implanted in 20 Large White female pigs with a ratio of baremetal/drug-eluting stents of 1:2. After 28 days, euthanasia and histomorphometry were performed. We defined the vessel injury score in accordance to whether the internal elastic lamina was intact or ruptured. Results. There were no differences between drug-eluting stents and bare metal stents in the intact internal elastic lamina group regarding neointimal area or % restenosis (1.3 [1.1-2.2]) vs 2.0 [1.3-2.5] mm2; P=.6; and 14.0 [12.1-20.8] vs 22.2 [14.1-23.3] %; P=.5). We assessed statistically significant differences for the ruptured internal elastic lamina group, (neointimal area 1.2 [0.8-2.0] vs 2.9 [2.3-3.7] mm2; P=.001 and % restenosis 16.63 [11.2-23.5] vs 30.4 [26.4-45.7] %; P=.001). Conclusions. In our swine model, we did not find any differences between proliferative response of drug-eluting stents and bare metal stents when the internal elastic lamina is intact; differences are only found when vascular injury is deeper (AU)

Biomechanical, histological and histomorphometric analyses of calcium phosphate cement compared to PMMA for vertebral augmentation in a validated animal model.

INTRODUCTION: Calcium phosphate cements (biocements) are alternative materials for use in vertebral augmentation procedures, and are a potential solution to problems associated with polymethylmethacrylate (PMMA) cements. The aim of this study is to demonstrate the utility of percutaneously injected biocements compared with PMMA in a validated animal model of osteoporosis. MATERIALS AND METHODS: Fortyseven augmentation procedures were performed on 11 osteoporotic sheep. 9 vertebrae were augmented with PMMA and 38 with a biocement. The animals were killed in four groups: at 7 days, 3 months, 6 months, and 1 year after intervention. Radiological study and TC of the pieces were obtained to evaluate for leakage, cement diffusion, and integration. In total, 26 biomechanic studies and 27 histomorphometry analyses were performed, included control vertebrae. RESULTS: In 20.9% of the vertebrae, the hole was empty at sacrifice. The pattern of fracture was heterogeneous, and cement augmentation did not increase vertebral strength or decrease vertebral stiffness compared to control vertebrae, with neither PMMA or biocement. The rate of remodeling of the biocement was not predictable. In the single majority, there is peripheral remodeling, staying the volume of injected biocement stable. CONCLUSIONS: Even though this animal model may not be useful to analyze the biomechanical pattern of treated vertebrae, it demonstrates that the percutaneous use of biocements in vertebral augmentation techniques is not predictable. This is one reason not to recommend its use presently as a substitute for PMMA in vertebral reinforcement procedures.

[Instent restenosis related to vessel injury score degree. Are current experimental models valid for drug-eluting stents analysis?]. / La reestenosis en el stent depende del daño vascular inducido. ¿Son válidos los modelos experimentales actuales de análisis de los stents farmacoactivos?

INTRODUCTION AND OBJECTIVES: Drug-eluting stents are useful for preventing restenosis, but the patho-physiological processes involved in the proliferative response after implantation are still not known in detail. The aim of this study is to compare the coronary vascular histomorphometry after implanting drug-eluting stents and bare metal stents in a swine model. METHODS: Sixty stents were randomly implanted in 20 Large White female pigs with a ratio of baremetal/drug-eluting stents of 1:2. After 28 days, euthanasia and histomorphometry were performed. We defined the vessel injury score in accordance to whether the internal elastic lamina was intact or ruptured. RESULTS: There were no differences between drug-eluting stents and bare metal stents in the intact internal elastic lamina group regarding neointimal area or % restenosis (1.3 [1.1-2.2]) vs 2.0 [1.3-2.5] mm²; P=.6; and 14.0 [12.1-20.8] vs 22.2 [14.1-23.3] %; P=.5). We assessed statistically significant differences for the ruptured internal elastic lamina group, (neointimal area 1.2 [0.8-2.0] vs 2.9 [2.3-3.7] mm²; P=.001 and % restenosis 16.63 [11.2-23.5] vs 30.4 [26.4-45.7] %; P=.001). CONCLUSIONS: In our swine model, we did not find any differences between proliferative response of drug-eluting stents and bare metal stents when the internal elastic lamina is intact; differences are only found when vascular injury is deeper.

Ventricular arrhythmias and mortality associated with isoflurane and sevoflurane in a porcine model of myocardial infarction.

Ischemia of the myocardium can lead to reversible or irreversible injury depending on the severity and duration of the preceding ischemia. Here we compared sevoflurane and isoflurane with particular reference to their hemodynamic effects and ability to modify the effects of acute severe myocardial ischemia and reperfusion on ventricular arrhythmias and mortality in a porcine model of myocardial infarction. Female Large White pigs were premedicated with ketamine, midazolam, and atropine. Propofol was given intravenously for the anesthetic induction, and anesthesia was maintained with isoflurane or sevoflurane. Endovascular, fluoroscopy-guided, coronary procedures were performed to occlude the midleft anterior descending artery by using a coronary angioplasty balloon. After 75 min, the balloon catheter system was withdrawn and the presence of adequate reperfusion flow was verified. The pigs were followed for 2 mo, and overall mortality rate was calculated. The isoflurane group showed lower arterial pressure throughout the procedure, with the difference reaching statistical significance after induction of myocardial ischemia. The ventricular fibrillation rate was higher in isoflurane group (81.3%) than the sevoflurane group (51.7%; relative risk, 1.57 [1.03 to 2.4]). Overall survival was lower in the isoflurane group (75%) than the sevoflurane group (96.4%). In conclusion, in this porcine model of myocardial ischemia and reperfusion, sevoflurane was associated with higher hemodynamic stability and fewer ventricular arrhythmias and mortality than was isoflurane.

Endothelialization of nonapposed stent struts located over the origin of a side branch: results with different carbofilm-coated stents.

OBJECTIVE: To evaluate the degree of endothelialization of the nonapposed struts located at the ostia of side branches. BACKGROUND: Endothelialization of coronary stents has got considerable relevance because of the phenomenon of late thrombosis. Bifurcation location and incomplete stent apposition have been linked to this complication. METHODS: Domestic pigs (n = 11; weight: 25 +/- 3 kg) were anesthetized and had one stent per coronary artery implanted: one stainless steel (Tecnic), one cobalt-chromium (Chrono), and one tacrolimus-eluting stent (Janus), all of them being Carbofilm-coated (Sorin). One, three, or seven days postprocedure, the pigs were sacrificed, the hearts explanted, and longitudinal sections examined by surface electron microscopy to quantify the percentage of the strut endothelialized over the branches and in the total surface. RESULTS: Forty-four side branches (25 stents) that had stent struts over their origin were evaluated. Different patterns of endothelialization were observed, from the total absence to the complete endothelialization. There were no significant differences in relation to type of stent or to the artery treated. The predictors of higher percentage of endothelialization were the ratio of metal to branch diameter (P = 0.04) and better endothelialization in the rest of the stent (P = 0.0002), only this parameter maintaining significant correlation (P = 0.03) in multivariate analysis. CONCLUSIONS: Carbofilm-coated stent struts located over the origin of side branches follow the pattern of endothelialization for the rest of the stent, even in the case of tacrolimus-eluting stent.

Closed-chest experimental porcine model of acute myocardial infarction-reperfusion.

INTRODUCTION: Progress in cardiovascular regenerative medicine research requires the availability of appropriate experimental animal models that are as close to humans as feasible. Our objective was to assess the validity of a porcine endovascular model of myocardial infarction and reperfusion. METHODS: Fifteen domestic pigs (Large White race) were anesthetized and pre-medicated with amiodarone. Endovascular fluoroscopy-guided coronary procedures were performed to occlude the mid-left anterior descending artery using a coronary angioplasty balloon. Occlusion was confirmed by angiography and electrocardiography. After 75 min the balloon catheter system was withdrawn and the presence of reperfusion flow was verified. The animals were sacrificed after 1 and 2 weeks of follow-up, the hearts were explanted, and the extent of myocardial infarction with respect to the left ventricle was quantified. RESULTS: Overall survival rate was 67%. Five animals died prematurely: 3 showing signs of heart failure, 1 had reperfusion failure (final TIMI flow grade 1) and 1 succumbed to acute stress. The most common adverse event was ventricular fibrillation (87% of the animals) and defibrillation was effective in all affected animals. The extent of myocardial infarct in the animals followed-up for 1 and 2 weeks was similar (20.4+/-4.3% vs. 20.9+/-2.8%, respectively; p=0.8) but was significantly greater in the animals that died prematurely (29.5+/-3.6%, p=0.02). CONCLUSIONS: The endovascular porcine model we have explored constitutes a feasible and reproducible alternative for the evaluation of human myocardial infarction and reperfusion.