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Bradypus variegatus, espécie pertencente à família Bradypodidae e à superordem Xenarthra, pode ser considerada modelo biológico de caráter multidisciplinar. Assim, realizou-se um trabalho de descrição anatômica da artéria carótida externa (ACE) e dos seus ramos no bicho-preguiça B. variegatus. Utilizaram-se 10 animais adultos, sendo todos fêmeas, que foram submetidos à dissecação, constatando-se que a artéria (a.) carótida comum se bifurca, em externa e interna, no nível do primeiro anel traqueal. A ACE, então, segue estendendo-se até a maxila, onde emite ramos para a região temporal e para o polo posterior do olho. Em todos os animais estudados, foram observados sete ramos principais da ACE, que, segundo a sua origem e localização, foram denominados como a. auricular, a. lingual, a. facial, a. alveolar, a. inferior, a. temporal, a. maxilar e a. oftálmica. Os ramos maxilar e oftálmico correspondem aos terminais e os demais são ramos colaterais. Em 50% dos animais analisados, foi verificada a presença de anastomoses arteriais e 40% deles apresentaram o acréscimo de um ramo aos principais. Desses, 30% demonstraram a presença de um ramo traqueal e 10% de um ramo sublingual, sendo esses ramos colaterais.(AU)

Bradypus variegatus is a species belonging to the family Bradypodidae and superorder Xenarthra, which should be considered as a multidisciplinary biological model. Thus, an anatomical description of the external carotid artery (ACE) and its branches in sloth B. variegatus was studied. Ten adult animals, all of them female, were submitted to dissection, and it was observed that the common carotid artery (a.) bifurcates in external and internal at the level of the first tracheal ring. Then, ACE extends through the maxilla where it launches branches to the temporal region and posterior eye side. For all sampled animals, seven principal branches of ACE were observed, and according to their origin and location were denominated as auricular, lingual, facial, bottom alveolar, temporal, maxillary and ophthalmic arteries. The maxillary and ophthalmic branches correspond to the terminals and the other branches are collateral. Presence of arterial anastomoses was observed in 50% of the sampled animals and 40% of them had increase of a branch on the principal. In these, 30% had presence of one tracheal branch and 10% of a sublingual branch, considering these branches as collateral.(AU)

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Bradypus variegatus, espécie pertencente à família Bradypodidae e à superordem Xenarthra, pode ser considerada modelo biológico de caráter multidisciplinar. Assim, realizou-se um trabalho de descrição anatômica da artéria carótida externa (ACE) e dos seus ramos no bicho-preguiça B. variegatus. Utilizaram-se 10 animais adultos, sendo todos fêmeas, que foram submetidos à dissecação, constatando-se que a artéria (a.) carótida comum se bifurca, em externa e interna, no nível do primeiro anel traqueal. A ACE, então, segue estendendo-se até a maxila, onde emite ramos para a região temporal e para o polo posterior do olho. Em todos os animais estudados, foram observados sete ramos principais da ACE, que, segundo a sua origem e localização, foram denominados como a. auricular, a. lingual, a. facial, a. alveolar, a. inferior, a. temporal, a. maxilar e a. oftálmica. Os ramos maxilar e oftálmico correspondem aos terminais e os demais são ramos colaterais. Em 50% dos animais analisados, foi verificada a presença de anastomoses arteriais e 40% deles apresentaram o acréscimo de um ramo aos principais. Desses, 30% demonstraram a presença de um ramo traqueal e 10% de um ramo sublingual, sendo esses ramos colaterais.(AU)

Bradypus variegatus is a species belonging to the family Bradypodidae and superorder Xenarthra, which should be considered as a multidisciplinary biological model. Thus, an anatomical description of the external carotid artery (ACE) and its branches in sloth B. variegatus was studied. Ten adult animals, all of them female, were submitted to dissection, and it was observed that the common carotid artery (a.) bifurcates in external and internal at the level of the first tracheal ring. Then, ACE extends through the maxilla where it launches branches to the temporal region and posterior eye side. For all sampled animals, seven principal branches of ACE were observed, and according to their origin and location were denominated as auricular, lingual, facial, bottom alveolar, temporal, maxillary and ophthalmic arteries. The maxillary and ophthalmic branches correspond to the terminals and the other branches are collateral. Presence of arterial anastomoses was observed in 50% of the sampled animals and 40% of them had increase of a branch on the principal. In these, 30% had presence of one tracheal branch and 10% of a sublingual branch, considering these branches as collateral.(AU)

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The facial artery (a branch of the external carotid artery) is the main artery of the face. It gives rise to seven branches viz. inferior labial, superior labial, inferior alar, superior alar, lateral nasal and angular arteries, which are variable. This study included a dissection of twenty embalmed adult cadaveric head and neck specimens. The parameters of origin, branching patterns, termination and variations were analysed and compared with sex and laterality. The facial artery followed the standard anatomical description of origin in 84.62 % of the sample. Variations: (i) origin as a linguofacial trunk in 12.82 % and (ii) high origin in 2.56 % was observed. Male specimens displayed a higher number of linguofacial trunk origins (7.69 %). The branching patterns of the facial artery was classified into six types, with subtypes for Types 1 and 2. Subtype 1-A (standard anatomical description with early termination) occurred in most of the sample (46.15 %). Males were found to have more variations in branching patterns than females (48.72 % and 41.03 % respectively). Termination of the facial artery was as follows: inferior labial artery (5.13 %), superior labial artery (10.26 %), inferior alar artery (10.26 %), superior alar artery (46.15 %), lateral nasal artery (5.13 %), and angular artery (20.51 %). A single case (2.56 %) of an abortive artery was noted. Statistical analysis showed that sex was independent of each parameter observed in this study. Anatomical knowledge of the facial artery is of importance to clinicians and surgeons during procedures such as musculomucosal, island flaps and aesthetic dermatology.

La arteria facial (una rama de la arteria carótida externa) es la arteria principal de la cara. Da lugar a siete ramas: labial inferior, labial superior, alar inferior, alar superior, arterias nasales y angulares laterales, además de ramas pequeñas variables. Este estudio incluyó una disección de veinte muestras de cabeza y cuello de cadáveres adultos fijados. Los parámetros de origen, patrones de ramificación, terminación y variaciones fueron analizados y comparados con el sexo y la lateralidad. La arteria facial se originó de manera normal en el 84,62 % de la muestra. Variaciones: (i) origen como tronco linguofacial en 12.82 % y (ii) se observó un origen alto en 2,56 %. Las muestras en los hombres mostraron un mayor número de orígenes del tronco linguofacial (7,69 %). Los patrones de ramificación de la arteria facial se clasificaron en seis tipos, con subtipos para los Tipos 1 y 2. El subtipo 1-A (descripción anatómica normal con terminación temprana) se observó en (46,15 %) de la muestra. Las muestras de varones tenían una mayor variación en los patrones de ramificación que las muestras de mujeres, 48,72 % y 41,03 % respectivamente. La terminación de la arteria facial fue la siguiente: arteria labial inferior (5,13 %), arteria labial superior (10,26 %), arteria alar inferior (10,26 %), arteria alar superior (46,15 %), arteria nasal lateral (5,13 %) y arteria angular (20,51 %). Se observó un solo caso (2,56 %) de una arteria abortiva. El análisis estadístico mostró que el sexo era independiente de cada parámetro observado en este estudio. El conocimiento anatómico de la arteria facial es importante para los médicos y cirujanos durante procedimientos como colgajos musculomucosal y en la dermatología estética.

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The major arterial supply to the thyroid gland is from the superior and inferior thyroid arteries, arising from the external carotid artery and the thyrocervical trunk respectively. The external laryngeal nerve runs in close proximity to the origin of the superior thyroid artery in relation to the thyroid gland. The superior thyroid artery is clinically important in head and neck surgeries. Objectives: To locate the origin of the superior thyroid artery, because wide variability is reported. To provide knowledge of possible variations in its origin, because it is important for surgical procedures in the neck. Methods: The origin of the superior thyroid artery was studied by dissecting sixty adult human hemineck specimens from donated cadavers in a Department of Anatomy. Results: The highest incidence observed was origin of the superior thyroid artery from the external carotid artery (88.33%), whereas origin from the common carotid bifurcation only occurred in 8.33%. However, in 3.33% of cases, the superior thyroid artery originated from the common carotid artery and in a single case, the external laryngeal nerve did not cross the stem of the superior thyroid artery at all, but ran ventral and parallel to the artery. Conclusions: It is important to rule out anomalous origin of superior thyroid artery and verify its relationship to the external laryngeal nerve prior to ligation of the artery in thyroid surgeries, in order to prevent iatrogenic injuries. Moreover, because anomalous origins of the superior thyroid artery are only anatomic variants, thorough knowledge of these is decisive for head and neck surgeries

O suprimento arterial principal para a glândula tireoide provém das artérias tireoideas superior e inferior, que têm origem na artéria carótida externa e no tronco tireocervical, respectivamente. O nervo laríngeo externo faz um percurso bem próximo à origem da artéria tireoidea superior em relação à glândula tireoide. A artéria tireoidea superior é clinicamente importante em cirurgias da cabeça e do pescoço. Objetivos: Localizar a origem da artéria tireoidea superior, considerando a ampla variabilidade descrita na literatura; e oferecer informações sobre possíveis variações em sua origem, devido à importância disso para procedimentos cirúrgicos realizados no pescoço. Métodos: A origem da artéria tireoidea superior foi estudada dissecando-se 60 espécimes de hemipescoço adulto de cadáveres humanos doados ao Departamento de Anatomia. Resultados: A maior incidência observada foi da artéria tireoidea superior com origem na artéria carótida externa (88,33%), enquanto a origem na bifurcação da artéria carótida comum ocorreu em apenas 8,33%. No entanto, em 3,33% dos casos, a artéria tireoidea superior teve origem na artéria carótida comum, e em um único caso, o nervo laríngeo externo não cruzou o tronco da artéria tireoidea superior em nenhum momento, embora tenha cursado ventral e paralelamente a essa artéria. Conclusões: É importante descartar origem anômala da artéria tireoidea superior e confirmar sua relação com o nervo laríngeo externo antes da ligadura da artéria em cirurgias da tireoide, para evitar efeitos iatrogênicos. Além disso, como origens anômalas da artéria tireoidea superior são apenas variantes anatômicas, o conhecimento detalhado dessas variações é decisivo para cirurgias da cabeça e do pescoço

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The variations in the origin of the facial and lingual arteries are very important in maxillofacial, head and neck surgery procedures. This study is a case report in which the common origin is described in the facial and lingual artery in a lingual-facial trunk (LFT) on the left side of a female corpse from Spain. In the examination, a diameter of 2.17 mm and a length of 8.84 mm are shown. It was located 12.04 mm from the carotid bifurcation and 9.31 mm from the origin of the superior thyroid artery. The variation in biometric values shown, are anatomical findings in the neck dissection of a corpse. Moreover, taking into account the surgical procedures, which involve the origin of facial and lingual artery, because it is the most common variation and could cause complications.

Las variaciones del origen de la arteria facial y lingual son importantes en los procedimientos de cirugía maxilofacial y de cabeza y cuello. Reportamos un caso en el que se describe el origen común de las arterias facial y lingual en un tronco linguofacial en el lado izquierdo en el cadáver de una mujer de origen español. En la examinación, el tronco presentó un diámetro de 2,17 mm y una longitud de 8,84 mm. Se ubicó a 12,04 mm de la bifurcación carotidea y a 9,31 mm del origen de la arteria tiroidea superior. La variación en los valores biométricos presentados constituyen un hallazgo anatómico en una disección de cuello de un cadáver, además ser tomada en cuenta en los procedimientos quirúrgicos que involucren el origen de la arteria facial y lingual, pues al ser la variación más común podría generar complicaciones.

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PURPOSE: To describe a technique for micro catheterization of the external ophthalmic artery (EO) in pigs for investigational and training purposes. METHODS: Carotid angiography was performed in seven male domestic pigs. The external ophthalmic artery was reached with a microcatheter in order to administer a neoplastic drug in the eye. RESULTS: The external ophthalmic artery could be found arising from the infraorbital (IO) artery in the bend of the internal maxillary (IM) artery. It could be reached in every animal. CONCLUSION: Following anatomic landmarks of the external carotid (EC) artery the ophthalmic artery can be easily reached and catheterized for training and investigational purposes.

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The external carotid artery (ECA) is the main artery of the head and the neck region. Carotid bifurcation (CB), which is one of the place where the atherosclerotic plaques are most commonly seen. The surgical procedure of these plaques which causes cerebral vascular accident (CVA) is carotid endarterectomy. In this surgical procedure, the knowledge of the anatomical courses and variations of the carotid artery increased the surgery performance. In our study, we aimed to introduce the course, the location and the variation of the ECA's and their branches. This study is carried out on multidetector computerized tomography angiography of the ECA's of 50 men and 50 women, totally 200 ECA's (100 right, 100 left). The measurement of the inner diameter of the common carotid artery (CCA) and the ECA was evaluated. The location of the CB was determined and its vertical distance to the gonion measured. We found that the superior thyroid artery (STA) originated from the CCA, the CB and the ECA. The vertical distances between the CB and the STA, lingual (LA), facial (FA) occipital (OA) were measured. The ECA and its branches were recorded. We believe that the assessment of the ECA morphometrically may comprise control groups of diseases related to the vessel diameter and this data may be used as reference in clinic and surgery. Knowing the anatomical details and variations is vital to prevent unpredictable complications in surgery.

La arteria carótida externa (ACE) es la principal arteria de la cabeza y de la región del cuello. La bifurcación carotídea (BC) es uno de los lugares donde las placas ateroscleróticas son más frecuentes. El procedimiento quirúrgico para tratar estas placas que causan el accidente vascular cerebral (AVC) es la endarterectomía carotídea. En este procedimiento quirúrgico, el conocimiento de los cursos anatómicos y variaciones de la arteria carótida aumenta el rendimiento de la cirugía. El objetivo de nuestro estudio fue presentar el trayecto, localización y variación de la ACE y sus ramas. El estudio se realizó mediante angiografía multidetector por tomografía computarizada de la ACE de 50 hombres y 50 mujeres, totalizando 200 ACE (100 derechas y 100 izquierdas). Se evaluaron el diámetro interior de la arteria carótida común (ACC) y la ACE. Se determinó la ubicación de la BC y se midió la distancia vertical hasta el gonion. Se observó que la arteria tiroidea superior (ATS) se originó desde la ACC, la BC y la ACA. Las distancias verticales entre la BC, y las arterias tiroídea superior, lingual (AL), facial (AF) y occipital (AO) fueron medidas. La ACE y sus ramas se registraron. Creemos que la evaluación morfométrica de la ACE puede comprender grupos de control de las enfermedades relacionadas con el diámetro de los vasos, y estos datos pueden ser utilizados como referencia clínica y quirúrgica. El conocimiento de los detalles anatómicos y variaciones es de vital importancia para evitar complicaciones imprevisibles en la cirugía.

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PURPOSE: To report initial findings with the GORE Flow Reversal System®, with a focus on major/minor adverse events in the 30 first postoperative days. METHODS: The first 24 patients submitted to carotid angioplasty using the GORE system, from June 2010 to May 2012, were retrospectively assessed with regard to indications, anatomic details, technical difficulties, and early clinical outcomes, including major (stroke, death, acute myocardial infarction) and minor (hematoma) adverse events. RESULTS: Systemic hypertension was present in 100% of the patients, diabetes mellitus in 58.3%, and coronary disease in 37.5%. Type II aortic arch was encountered in 62.5% of the patients and atherosclerotic lesion predominantly at the carotid bifurcation affecting the internal and common carotid arteries in 79.2%. Angiographic data revealed contralateral carotid arteries with <50% stenosis in 95.8% of cases and preservation of cerebral blood flow in 95.8%. All procedures but one were technically successful. Mean cerebral flow reversal time was 14.9 minutes, with a statistically significant difference between the first 12 (17.9 minutes) and the last 12 patients treated (11.6 minutes) (p<0.001). Intolerance to flow reversal was observed in 17.4% of the cases. Technical difficulties were experienced in 1 patient (4.2%). Clinical outcomes included 4.2% of stroke and 12.5% of hematomas at arterial puncture sites. CONCLUSION: The system was technically effective. A significant reduction in cerebral flow reversal time was observed, and the rates of early major/minor adverse events were within acceptable limits, suggesting that the device is safe and effective.

OBJETIVO: Relatar os achados iniciais da utilização do GORE Flow Reversal System® (Sistema de Fluxo de Reversão), com foco em eventos adversos maiores/menores nos primeiros 30 dias do pós-operatório. MÉTODOS: Os primeiros 24 pacientes submetidos a angioplastia carotídea com a utilização do sistema GORE, de junho de 2010 a maio de 2012, foram avaliados retrospectivamente com relação a indicações, detalhes anatômicos, dificuldades técnicas e desfechos clínicos imediatos, incluindo eventos adversos maiores (acidente vascular cerebral, morte, infarto agudo do miocárdio) e menores (hematoma). RESULTADOS: Hipertensão sistêmica estava presente em 100% dos pacientes, diabete melito em 58,3% e doença coronariana em 37,5%. Arco aórtico tipo II foi encontrado em 62,5% dos pacientes e lesão de aterosclerose predominantemente na bifurcação carotídea que afeta as artérias carótidas internas e comuns em 79,2%. Dados angiográficos revelaram artérias carótidas contralaterais com estenose <50% em 95,8% de casos e preservação de fluxo sanguíneo cerebral em 95,8%. Todos os procedimentos, com exceção de um, foram tecnicamente bem sucedidos. A média do tempo de reversão do fluxo cerebral foi de 14,9 minutos, com uma diferença estatisticamente significativa entre os primeiros 12 pacientes (17,9 minutos) e os últimos 12 pacientes tratados (11,6 minutos) (p<0,001). Intolerância à reversão de fluxo foi observada em 17,4% dos casos. Ocorreram dificuldades técnicas em 1 paciente (4,2%). Desfechos clínicos incluíram 4,2% de acidente vascular cerebral e 12,5% de hematomas em locais de punção arterial. CONCLUSÃO: O sistema foi tecnicamente eficaz. Uma redução significativa no tempo de reversão do fluxo cerebral foi observada e as taxas de eventos adversos maiores/menores ficaram dentro de limites aceitáveis, sugerindo que o dispositivo é seguro e eficaz.

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CONTEXTO: O conhecimento das estruturas anatômicas da artéria carótida externa por meio do estudo estereoscópico pode determinar melhores resultados em microcirurgias da artéria carótida externa. OBJETIVO: Descrever as estruturas da artéria carótida externa sob a visão estereoscópica, identificando seus múltiplos aspectos. MÉTODOS: Doze regiões cervicais foram dissecadas, utilizando-se microscópico cirúrgico com 3 a 40x de aumento. As dissecções anatômicas foram documentadas utilizando-se a técnica para obtenção de imagens tridimensionais (3D), objetivando a produção de impressões estereoscópicas. RESULTADOS: O uso da técnica estereoscópica possibilitou a abordagem da circulação arterial extracraniana, sendo realizados estudos cirúrgicos do tipo combinado fossa posterior e fossa infratemporal, tornando as microcirurgias e os procedimentos neurocirúrgicos vasculares mais precisos. CONCLUSÃO: O uso das imagens obtidas pela técnica estereoscópica produziu um resultado mais assertivo em relação ao estudo da anatomia para a microcirurgia e procedimentos neurocirúrgicos, facilitando melhor aprendizado previamente à realização de procedimentos complexos em neurocirurgia.

BACKGROUND: The knowledge on the anatomical structures of the external carotid artery through the stereoscopic study may provide better results in microsurgical treatment of the external carotid artery. OBJECTIVE: To describe the structures of the external carotid artery under stereoscopic vision, identifying its multiple aspects. METHODS: Twelve cervical regions were dissected using a surgical microscope with 3 to 40x magnification. The anatomical dissections were documented using the technique to obtain three-dimensional images (3D), aiming at producing stereoscopic prints. RESULTS: The use of the stereoscopic technique enabled the stereoscopic approach to extracranial arterial circulation, and it was followed by a combined posterior fossa and infratemporal approach, making microvascular surgery and neurosurgical procedures more precise. CONCLUSION: The use of images obtained through the stereoscopic technique produced a more assertive result in relation to the anatomy study for microsurgical or neurosurgical procedures, facilitating a better learning before performing complex procedures in neurosurgery.

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The external carotid artery originates branches to face structures. The superior thyroid, lingual and facial arteries are originated from this vessel as artery trunks or separately. The aim of this study was to determinate the arrangement frequency of these artery branches. For this, thirty six (36) hemi-heads of adult cadavers from both genders were studied. The anatomic parts were fixed in 10% of formalin and dissected. The superior thyroid, lingual and facial arteries were analyzed in terms of their origins. The superior thyroid, lingual and facial arteries originated separately from the external or common carotid artery in 77.8% of the cases. A linguofacial trunk was observed in 19.9% of the cases and a thyrolingual trunk in 2.8%. A thyrolinguofacial trunk was not observed. In 51.2% cases the superior thyroid artery originated directly from the external carotid artery, in 45.3% from the bifurcation of the common carotid artery, and in 3.5% from the common carotid artery. Thus, the superior thyroid, lingual and facial arteries more frequently showed a separate origin from the external or common carotid artery. Among the combined artery trunks, the linguofacial trunk was most frequently observed, followed by the thyrolingual trunk. The superior thyroid artery originated more frequently from the external or common carotid artery; however, it also could emerge from the bifurcation of the common carotid artery.

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UNLABELLED: The temporal muscle is greatly used for forming myofascial flaps and transposition in cases of reconstructive and reparative plastic surgery of the face and neck. Despite this important application, lack of success has been reported, probably because of lack of knowledge of the anatomical characteristics of this muscle, such as variations in its blood supply. OBJECTIVES: To investigate the blood supply of the temporal muscle in order to provide an anatomical basis for reconstructive and reparative surgery of the face using flaps from the temporal muscle. This study was conducted by dissecting 21 half faces from cadavers of children (13 male and 8 female) that had been injected with neoprene latex through the common carotid artery. The temporal muscle usually received three or four arterial branches coming from the maxillary and superficial temporal arteries. The branches of the maxillary artery could be separate (anterior deep temporal, posterior deep temporal and accessory deep temporal arteries) or together with other branches of the maxillary artery, forming trunks. The branches of the superficial temporal artery were always separate (middle temporal artery). The anterior deep temporal artery originated in front of the coronoid process and the posterior deep temporal artery behind it. The numbers of arterial branches in the anterior and middle thirds of the muscle were similar and slightly greater than the number in the posterior third. The most frequent arterial branch in the anterior third was the anterior deep temporal artery; in the middle third, it was the posterior deep temporal artery; and in the posterior third, it was the middle temporal artery. The most frequent patterns of arterial branch presence in the temporal muscle were: a) anterior deep temporal, posterior deep temporal and middle temporal arteries; and b) anterior deep temporal, posterior deep temporal, accessory deep temporal and middle temporal arteries. The accessory deep temporal artery is a direct branch from the maxillary artery that originates at the level of the coronoid process of the mandible and participates in irrigating the anterior and middle thirds of the muscle.

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Los angiofibromas juveniles nasofaríngeos son los tumores nasofaríngeos benignos más frecuentes. Se presentan predominantemente en varones púberes. Los síntomas más frecuentes son obstrucción nasal y epistaxis recurrentes. A pesar de que su comportamiento biológico es benigno, tiende a crecer destruyendo las estructuras óseas vecinas a la nasofaringe hasta extenderse a la base del cráneo. Recurren con una frecuencia que va del 35 al 57 por ciento después de la extirpación quirúrgica incompleta. El diagnóstico diferencial debe hacerse con hemangiopericitoma, tumor fibroso solitario, hemangiomas, schwannoma e histiocitoma fibroso

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La 2-(2-aminoetil)-quinolina (D-1997) es un derivado quinolínico capaz de mimetizar el efecto contráctil de la serotonina (5-hidroxitriptamina; 5HT) en la vena safena y la arteria basilar del perro. Debido a la similitud que parece existir en el tipo de receptor serotónergico presente en estas preparaciones y el que media la vasoconstricción de la cirulación carotídea del perro, el presente estudio analiza el perfil hemodinámico del D-1997 en el lecho arterial carotídeo externo de perros vago simpatectomizados anestesiados con pentobarbital. Los efectos del D-1997 se compararon con aquellos producidos por la 5-HT y el agente antimigrañoso, sumatriptan. Las infusiones intracarotídeas (i.c.), durante 1 min, de D-1997 (10, 30, 100, 300 y 1000 µg/min), 5HT (0.3, 1, 3, 10, 30 y 100 µg/min), y sumatriptan (3, 10, 30 y 100 µg/min), produjeron decrementos del flujo sanguíneo carotídeo externo (FSCE) dependientes de la dosis empleada. Debido a que estos efectos no se vieron acompañados de modificaciones en la presión arterial, los agonistas produjeron incrementos dosis-dependientes de la resitencia carotídea externa (RCE). Las respuestas vasoconstrictoras inducidas por el D-1997 y la 5-HT fueron de corta duración (hasta 10 min), mientras que aquellas producidas por el sumatriptan fueron de larga duración (hasta 40 min). Los cambios hemodinámicos producidos por el D-1997 y la 5-HT y el sumatriptan en la carótida externa no modificaron los valores basales de resitencia en el lecho arterial de la carótida común contralateral, hecho que indica un efecto local. El orden de potencia agonista aparente fue 5-HT>sumatriptan>D-1997, mientras que el orden de eficacia, representada aquí como la respuesta máxima observada, siguió un patrón diferente, es decir, D-1997 ò sumatriptan > 5-HT. La administración repetida o la administración previa de 5-HT y sumatriptan no modificó las respuestas inducidas por este nuevo agonista; en consecuencia, el D-1997 se comportó como un agonista completo sin inducción de taquifilaxia. Los resultados de este estudio indican que, al igual que en la arteria basilar y en la vena safena del perro, el D-1997 es capaz de producir contracción del músculo liso vascular en el lecho arterial carotídeo externo del perro

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