Ultrassonografia contrastada por microbolhas (CEUS) e Doppler umbilical na gestação de cadelas braquicefálicas
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Data
2021-03-03
Autores
Silva, Priscila
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Universidade Estadual Paulista (Unesp)
Resumo
RESUMO – Os objetivos dos estudos foram realizar a avaliação da hemodinâmica gestacional fisiológica, envolvendo a dinâmica vascular da artéria umbilical e a perfusão de placentas normais e funcionais e então estabelecer parâmetros qualitativos e quantitativos de referência para cadelas braquicefálicas saudáveis e avaliar a vascularização e perfusão placentária em cadelas com anormalidades fetais próximas ao parto. Foram utilizados 44 fetos, provenientes de 22 cadelas braquicefálicas, e 9 fetos com anormalidades. Os exames ultrassonográficos foram realizados nos três terços da gestação, aos 25, 45 e 58 dias, neste ultimo momento, dos fetos com anormalidade gestacionais. Utilizou-se aparelho ACUSON S2000/SIMENS e transdutor multifrequencial matricial e linear. Foram avaliados dois fetos de cada fêmea, preferencialmente os localizados próximos a região de ovário. O modo Doppler espectral foi utilizado para mensuração eletrônica das variáveis Dopplerfluxométricas da artéria umbilical: velocidade sistólica (VS), velocidade diastólica (VD), tempo médio de velocidade mínima (TaMin), tempo médio de velocidade máxima (TaMax), índice de pulsatilidade (IP) e índice de resistência (IR). Após, foi realizada a CEUS utilizando o software de imagem harmônica (CADENCE) na avaliação qualitativa do contraste ultrassonográfico, identificando: uniformidade do preenchimento nas regiões placentárias (homogêneo ou heterogêneo), áreas de hipoperfusão, e se ao longo do período gestacional o padrão de realce sofreria alterações em relação a entrada e saída do contraste; e na quantitativa dos parâmetros de perfusão placentários: pico de intensidade do contraste (Fpeak em % de pixels), tempo para o pico (Ftp em s), tempo médio de transmissão (Fmtt em s), área sob a curva (Fauc) e inclinação da curva de entrada em pixels (Fpixels). As variáveis coletadas foram comparadas entre os fetos avaliados (normais e anormais) e entre os momentos pelo teste T-Student e ANOVA e correlacionadas pelo teste de Spearman. Nos fetos saudáveis as variáveis VS, VD, TaMax e TaMin aumentaram significativamente do M2 para o M3 (P<0,05), enquanto o IP (P<0,043) e o IR (P<0,001) diminuíram. Os parâmetros avaliados no CEUS permaneceram constantes durante todos os terços da gestação (P<0,05). Qualitativamente, em todos os momentos avaliados, a distribuição do contraste foi homogênea no tecido placentário. Foi possível acompanhar as adaptações vasculares materno-fetais conforme a progressão da gestação em cadelas, de forma a atender às crescentes demandas metabólicas do feto. Já nos fetos que apresentaram hidropsias os valores de Doppler foram semelhantes aos obtidos nos saudáveis (P<0,05), porém na avaliação com CEUS foi possivel verificar uma distribuição heterogênea, com menor intensidade de preenchimento do tecido placentário e um atraso nos tempos de perfusão (P<0,05), com acurácia diagnóstica próxima de 75%. A associação das técnicas dopplerfluxométricas e CEUS permitiu estabelecer parâmetros qualitativos e quantitativos da hemodinâmica gestacional fisiológica, em todos os terços da gestação, sendo possível correlacionar com desenvolvimento e manutenção de todo processo gestacional, sem evidência de alterações significativas na fisiologia do binômio materno-fetal; assim a CEUS demonstrou ser aplicável na detecção de falhas no preenchimento vascular placentário (disfunção tecidual) em fetos com anasarca e hidrocefalia. Adicionalmente, foram descritos os achados ultrassonográficos de alterações encontrados durante o exame pré natal, de alterações nas estruturas renais de um feto pela da ultrassonografia de alta definição, com descrito no relato de caso presente nesta tese.
ABSTRACT - The objectives of the studies were to evaluate the physiological gestational hemodynamics, involving the vascular dynamics of the umbilical artery and the perfusion of normal and functional placentas, and then to establish qualitative and quantitative reference parameters for healthy brachycephalic bitches and to evaluate the vascularization and placental perfusion in bitches with fetal abnormalities close to delivery. 44 fetuses were used, from 22 brachycephalic bitches, and 9 fetuses with abnormalities. Ultrasound examinations were performed in the three thirds of pregnancy, at 25, 45 and 58 days, at this last moment, of fetuses with gestational abnormalities. An ACUSON S2000 / SIMENS device and a multi-frequency matrix and linear transducer were used. Two fetuses from each female were evaluated, preferably those located near the ovary region. The spectral doppler mode was used to electronically measure the dopplerfluxometric variables of the umbilical artery: systolic velocity (VS), diastolic velocity (RV), mean minimum velocity time (TaMin), mean maximum velocity time (TaMax), pulsatility index ( IP) and resistance index (IR). Afterwards, CEUS was performed using the harmonic imaging software (CADENCE) in the qualitative evaluation of the ultrasound contrast, identifying: uniformity of filling in the placental regions (homogeneous or heterogeneous), areas of hypoperfusion, and whether, throughout the gestational period, the pattern of enhancement would change in relation to the entry and exit of the contrast; and in the quantity of placental perfusion parameters: peak contrast intensity (Fpeak in% of pixels), time to peak (Ftp in s), average transmission time (Fmtt in s), area under the curve (Fauc) and slope of the input curve in pixels (Fpixels). The variables collected were compared between the fetuses evaluated (normal and abnormal) and between the moments by the T-Student and ANOVA tests and correlated by the Spearman test. In healthy fetuses, the variables VS, VD, TaMax and TaMin increased significantly from M2 to M3 (P <0.05), while PI (P <0.043) and IR (P <0.001) decreased. The parameters evaluated in CEUS remained constant during all thirds of pregnancy (P <0.05). Qualitatively, in all evaluated moments, the distribution of contrast was homogeneous in the placental tissue. It was possible to monitor the maternal-fetal vascular adaptations according to the progression of gestation in bitches, in order to meet the increasing metabolic demands of the fetus, which allow it to develop properly. In the case of fetuses that presented hydrops, the Doppler values were similar to those obtained in the healthy ones (P <0.05), however, in the evaluation with CEUS it was possible to verify a heterogeneous distribution, with less intensity of filling of the placental tissue and a delay in the times of perfusion (P <0.05), with diagnostic accuracy close to 75%. The association of flow-through doppler techniques and CEUS allowed to establish qualitative and quantitative parameters of physiological gestational hemodynamics, in all thirds of pregnancy, of healthy brachycephalic bitches, being possible to correlate with the development and maintenance of the whole gestational process of healthy bitches, without evidence of significant changes in the physiology of the maternal-fetal binomial; thus, CEUS proved to be applicable in the detection of flaws in the placental vascular filling (tissue dysfunction) in fetuses with anasarca and hydrocephalus. In addition, the sonographic findings of alterations found during the prenatal examination, of alterations in the renal structures of a fetus by that of high definition ultrasonography, have been described, as described in the case report in this thesis.
ABSTRACT - The objectives of the studies were to evaluate the physiological gestational hemodynamics, involving the vascular dynamics of the umbilical artery and the perfusion of normal and functional placentas, and then to establish qualitative and quantitative reference parameters for healthy brachycephalic bitches and to evaluate the vascularization and placental perfusion in bitches with fetal abnormalities close to delivery. 44 fetuses were used, from 22 brachycephalic bitches, and 9 fetuses with abnormalities. Ultrasound examinations were performed in the three thirds of pregnancy, at 25, 45 and 58 days, at this last moment, of fetuses with gestational abnormalities. An ACUSON S2000 / SIMENS device and a multi-frequency matrix and linear transducer were used. Two fetuses from each female were evaluated, preferably those located near the ovary region. The spectral doppler mode was used to electronically measure the dopplerfluxometric variables of the umbilical artery: systolic velocity (VS), diastolic velocity (RV), mean minimum velocity time (TaMin), mean maximum velocity time (TaMax), pulsatility index ( IP) and resistance index (IR). Afterwards, CEUS was performed using the harmonic imaging software (CADENCE) in the qualitative evaluation of the ultrasound contrast, identifying: uniformity of filling in the placental regions (homogeneous or heterogeneous), areas of hypoperfusion, and whether, throughout the gestational period, the pattern of enhancement would change in relation to the entry and exit of the contrast; and in the quantity of placental perfusion parameters: peak contrast intensity (Fpeak in% of pixels), time to peak (Ftp in s), average transmission time (Fmtt in s), area under the curve (Fauc) and slope of the input curve in pixels (Fpixels). The variables collected were compared between the fetuses evaluated (normal and abnormal) and between the moments by the T-Student and ANOVA tests and correlated by the Spearman test. In healthy fetuses, the variables VS, VD, TaMax and TaMin increased significantly from M2 to M3 (P <0.05), while PI (P <0.043) and IR (P <0.001) decreased. The parameters evaluated in CEUS remained constant during all thirds of pregnancy (P <0.05). Qualitatively, in all evaluated moments, the distribution of contrast was homogeneous in the placental tissue. It was possible to monitor the maternal-fetal vascular adaptations according to the progression of gestation in bitches, in order to meet the increasing metabolic demands of the fetus, which allow it to develop properly. In the case of fetuses that presented hydrops, the Doppler values were similar to those obtained in the healthy ones (P <0.05), however, in the evaluation with CEUS it was possible to verify a heterogeneous distribution, with less intensity of filling of the placental tissue and a delay in the times of perfusion (P <0.05), with diagnostic accuracy close to 75%. The association of flow-through doppler techniques and CEUS allowed to establish qualitative and quantitative parameters of physiological gestational hemodynamics, in all thirds of pregnancy, of healthy brachycephalic bitches, being possible to correlate with the development and maintenance of the whole gestational process of healthy bitches, without evidence of significant changes in the physiology of the maternal-fetal binomial; thus, CEUS proved to be applicable in the detection of flaws in the placental vascular filling (tissue dysfunction) in fetuses with anasarca and hydrocephalus. In addition, the sonographic findings of alterations found during the prenatal examination, of alterations in the renal structures of a fetus by that of high definition ultrasonography, have been described, as described in the case report in this thesis.
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Palavras-chave
cães, ultrassonografia veterinária, ultrassonografia Doppler, meios de contraste, alterações gestacionais, Dogs, Veterinary ultrasound, Doppler ultrasound, Contrast media (diagnostic imaging), Gestational changes