RESUMO
Resumen Objetivos Describir morfológicamente un bloque visceral toracoabdominal de un caso de síndrome de la cimitarra. Proponer una hipótesis patogenética que explique el desarrollo de las conexiones venosas pulmonares de este síndrome. Método El espécimen anatómico se describió con el sistema secuencial segmentario. Se determinó el situs, las conexiones entre los segmentos cardíacos y las anomalías agregadas. Se describió la anatomía de ambos pulmones, incluida la conexión venosa pulmonar. Se elaboró una hipótesis patogenética que explica la conexión venosa pulmonar a través de una correlación entre la patología del síndrome y el desarrollo normal de las venas pulmonares. Resultados El situs fue solitus, las conexiones entre los segmentos cardíacos fueron normales, existió hipoplasia y displasia del pulmón derecho con secuestro del lóbulo inferior; las venas pulmonares derechas drenaron a un colector curvo en la porción suprahepática de la vena cava inferior y las venas pulmonares izquierdas lo hicieron a la aurícula izquierda. El secuestro pulmonar recibió irrigación a través de una colateral aortopulmonar. Existió una comunicación interauricular. Conclusiones La hipótesis patogenética propone que las conexiones venosas pulmonares de este síndrome representan la persistencia del horizonte XIV de Streeter (28-30 días de desarrollo), período en el que el seno de las venas pulmonares presenta conexión venosa doble con la aurícula izquierda y con un colector de la conexión primitiva que desemboca en la vitelina derecha de la que se deriva la porción suprahepática de la vena cava inferior.
Abstract Objectives To describe morphologically a toracoabdominal visceral block of a scimitar's syndrome case. We propose a pathogenetic theory wich explains the development of the pulmonary venous connection in this syndrome. Method The anatomic specimen was described with the segmental sequential system. The situs was solitus, the connections between the cardiac segments and the associated anomalies were determined. The anatomy of both lungs, including the venous pulmonary connection, was described. A pathogenetic hypothesis was made, which explains the pulmonary venous connection throw a correlation between the pathology of this syndrome and the normal development of the pulmonary veins. Results The situs was solitus, the connections of the cardiac chambers were normal; there were hypoplasia and dysplasia of the right lung with sequestration of the inferior lobe; the right pulmonary veins were connected with a curved collector which drainaged into the suprahepatic segment of the inferior vena cava; the left pulmonary veins were open into the left atrium. The sequestered inferior lobe of the right lung received irrigation throw a collateral aortopulmonary vessel. There was an atrial septal defect. Conclusions The pathogenetic hypothesis propose that the pulmonary venous connection in this syndrome represent the persistent of the Streeter's horizon XIV (28-30 days of development), period in which the sinus of the pulmonary veins has double connection, with the left atrium and with a primitive collector into the right viteline vein which forms the suprahepatic segment of the inferior vena cava.
Assuntos
Humanos , Síndrome de Cimitarra/embriologia , Veias Pulmonares/anatomia & histologia , Veias Pulmonares/embriologiaRESUMO
OBJECTIVES: To describe morphologically a toracoabdominal visceral block of a scimitar's syndrome case. We propose a pathogenetic theory wich explains the development of the pulmonary venous connection in this syndrome. METHOD: The anatomic specimen was described with the segmental sequential system. The situs was solitus, the connections between the cardiac segments and the associated anomalies were determined. The anatomy of both lungs, including the venous pulmonary connection, was described. A pathogenetic hypothesis was made, which explains the pulmonary venous connection throw a correlation between the pathology of this syndrome and the normal development of the pulmonary veins. RESULTS: The situs was solitus, the connections of the cardiac chambers were normal; there were hypoplasia and dysplasia of the right lung with sequestration of the inferior lobe; the right pulmonary veins were connected with a curved collector which drainaged into the suprahepatic segment of the inferior vena cava; the left pulmonary veins were open into the left atrium. The sequestered inferior lobe of the right lung received irrigation throw a collateral aortopulmonary vessel. There was an atrial septal defect. CONCLUSIONS: The pathogenetic hypothesis propose that the pulmonary venous connection in this syndrome represent the persistent of the Streeter's horizon xiv (28-30 days of development), period in which the sinus of the pulmonary veins has double connection, with the left atrium and with a primitive collector into the right viteline vein which forms the suprahepatic segment of the inferior vena cava.
Assuntos
Síndrome de Cimitarra/embriologia , Humanos , Veias Pulmonares/anatomia & histologia , Veias Pulmonares/embriologiaRESUMO
OBJECTIVE: To test the hypothesis that fetal pulmonary venous flow pulsatility index is lower during fetal respiratory movements than in apnea. DESIGN: Case control. SETTINGS/PATIENTS: Twenty-two normal fetuses of mothers without systemic disease were examined in apnea (controls) and in the presence of fetal respiratory movements (cases). Fetuses were examined by prenatal Doppler echocardiography with color flow mapping. The pulsatility index of the pulmonary vein was obtained by placing the pulsed Doppler sample volume over the right upper or left lower pulmonary vein, and calculating the ratio (maximum velocity [systolic or diastolic]-presystolic velocity/mean velocity). RESULTS: Mean gestational age was 28.9 +/- 2.9 weeks. During fetal apnea, mean systolic, diastolic, and presystolic velocities were, respectively, 0.35 +/- 0.08 m/s, 0.26 +/- 0.07 m/s, and 0.09 +/- 0.03 m/s. In the presence of fetal respiratory movements, mean systolic, diastolic, and presystolic velocities were, respectively, 0.33 +/- 0.1 m/s, 0.28 +/- 0.08 m/s, and 0.11 +/- 0.04 m/s. Pulsatility index pulmonary vein in apnea was 1.25 +/- 0.23 (1.69 to 0.82), and during fetal respiratory movements it was 0.97 +/- 0.2 (1.53 to 0.61). CONCLUSION: We showed a significant reduction in impedance of pulmonary venous flow, represented by pulmonary vein pulsatility index, during fetal respiratory movements, reflecting modifications of the left atrial dynamics and enhancement of left ventricular compliance.
Assuntos
Feto/fisiologia , Circulação Pulmonar/fisiologia , Veias Pulmonares/embriologia , Veias Pulmonares/fisiologia , Mecânica Respiratória/fisiologia , Função do Átrio Esquerdo/fisiologia , Velocidade do Fluxo Sanguíneo/fisiologia , Estudos de Casos e Controles , Diástole/fisiologia , Ecocardiografia Doppler , Feminino , Idade Gestacional , Humanos , Gravidez , Veias Pulmonares/diagnóstico por imagem , Fluxo Pulsátil/fisiologia , Sístole/fisiologia , Ultrassonografia Pré-Natal , Resistência Vascular/fisiologiaRESUMO
An anatomical-embryological correlation of anomalous venous pulmonary connection is presented to gain an insight of its pathogenesis. The basic publications on embryonic development of the pulmonary veins were analyzed in its two stages: the primary connection of these veins (collectors) with the embryonic systemic veins from which the definitive veins arise. These channels normally disappear once the pulmonary veins sinus is connected with the roof of the left atrium (secondary definitive connection); when the latter does not exist, any of the primitive channels persist and originates the anatomic sites of the anomalous venous pulmonary connection. The embryonic systemic veins are the right cardinal (superior vena cava and azygos vein), the left cardinal (venous coronary sinus and vertical vein) and the umbilical-vitelline (portal vein and ductus venosus). Other mechanisms are discussed such as ectopic origin of the primitive pulmonary vein in the roof of the right atrium and misplaced left of the atrial septum. The atrial septal defect is conditioned by the hemodynamics of this malformation. The knowledge of the pulmonary venous development is of great value in understanding the structure and the anatomic variants of this cardiovascular malformation in its total and partial forms.
Assuntos
Anormalidades Múltiplas/embriologia , Cardiopatias Congênitas/embriologia , Veias Pulmonares/embriologia , Humanos , Veias Pulmonares/anormalidadesRESUMO
An anatomical-embryological correlation of anomalous venous pulmonary connection is presented to gain an insight of its pathogenesis. The basic publications on embryonic development of the pulmonary veins were analyzed in its two stages: the primary connection of these veins (collectors) with the embryonic systemic veins from which the definitive veins arise. These channels normally disappear once the pulmonary veins sinus is connected with the roof of the left atrium (secondary definitive connection); when the latter does not exist, any of the primitive channels persist and originates the anatomic sites of the anomalous venous pulmonary connection. The embryonic systemic veins are the right cardinal (superior vena cava and azygos vein), the left cardinal (venous coronary sinus and vertical vein) and the umbilical-vitelline (portal vein and ductus venosus). Other mechanisms are discussed such as ectopic origin of the primitive pulmonary vein in the roof of the right atrium and misplaced left of the atrial septum. The atrial septal defect is conditioned by the hemodynamics of this malformation. The knowledge of the pulmonary venous development is of great value in understanding the structure and the anatomic variants of this cardiovascular malformation in its total and partial forms.
Assuntos
Humanos , Anormalidades Múltiplas/embriologia , Cardiopatias Congênitas/embriologia , Veias Pulmonares/embriologia , Veias Pulmonares/anormalidadesRESUMO
BACKGROUND: The usual positioning of the Doppler sample volume to assess fetal pulmonary vein flow is in the distal portion of the vein, where the vessel diameter is maximal. This study was performed to test the association of the pulmonary vein pulsatility index (PVPI) with the vessel diameter. METHODS AND RESULTS: Twenty-three normal fetuses (mean gestational age, 28.6+/-5.3 weeks) were studied by Doppler echocardiography. Pulmonary right upper vein flow was assessed adjacent to the venoatrial junction ("distal" position) and in the middle of the vein ("proximal" position). The vessel diameter was measured by 2D echocardiography with power Doppler, and the PVPI was obtained by the ratio (maximal velocity [systolic or diastolic peak]-minimal velocity [presystolic peak])/mean velocity. The statistical analysis used t test and exponential correlation studies. Mean distal diameter was 0.33+/-0.10 cm (0.11 to 0.57 cm), and mean proximal diameter was 0.16+/-0.08 cm (0.11 to 0.25 cm) (P<0.0001). Mean distal PVPI was 0.84+/-0.21 (0.59 to 1.38), and mean proximal PVPI was 2.09+/-0.59 (1.23 to 3.11) (P<0.0001). Exponential inverse correlation between pulmonary vein diameter and pulsatility index was highly significant (P<0.0001), with a determination coefficient of 0.439. CONCLUSIONS: In the normal fetus, the pulmonary venous flow pulsatility decreases from the lung to the heart, and this parameter is inversely correlated to the diameter of the pulmonary vein, which increases from its proximal to its distal portion. This study emphasizes the importance of the correct positioning of the Doppler sample volume, adjacent to the venoatrial junction, to assess pulmonary venous flow dynamics.