Comparison between Protocols for Management of Fetal Growth Restriction / Comparação entre protocolos de acompanhamento da restrição de crescimento fetal

Abstract This comprehensive review compares clinical protocols of important entities regarding the management of fetal growth restriction (FGR), published since 2015. Five protocols were chosen for data extraction. There were no relevant differences regarding the diagnosis and classification of FGR between the protocols. In general, all protocols suggest that the assessment of fetal vitality must be performed in a multimodally, associating biophysical parameters (such as cardiotocography and fetal biophysical profile) with the Doppler velocimetry parameters of the umbilical artery, middle cerebral artery, and ductus venosus. All protocols reinforce that the more severe the fetal condition, the more frequent this assessment should be made. The timely gestational age and mode of delivery to terminate the pregnancy in these cases can vary much between the protocols. Therefore, this paper presents, in a didactic way, the particularities of different protocols for monitoring FGR, in order to help obstetricians to better manage the cases.

Resumo Esta revisão compreensiva compara protocolos clínicos de entidades importantes em relação ao manejo da restrição de crescimento fetal (RCF), publicados desde 2015. Cinco protocolos foram escolhidos para a extração de dados. Não houve diferenças relevantes quanto ao diagnóstico e classificação da RCF entre os protocolos. Em geral, todos os protocolos sugerem que a avaliação da vitalidade fetal deve ser realizada de forma multimodal, associando parâmetros biofísicos (como cardiotocografia e perfil biofísico fetal) aos parâmetros dopplervelocimétricos da artéria umbilical, artéria cerebral média e ducto venoso. Todos os protocolos reforçam que quanto mais grave a condição fetal, mais frequente essa avaliação deve ser feita. A idade gestacional oportuna e o modo de parto para interromper a gravidez nesses casos podem variar muito entre os protocolos. Portanto, este trabalho apresenta, de forma didática, as particularidades de diferentes protocolos de acompanhamento de RCF, a fim de auxiliar os obstetras no melhor manejo dos casos.

Effects of Left Ventricular Assist and Aortic Graft Angle on Aortic Valve: A Hemodynamic Study / 医用生物力学

Objective To investigate the effect of left ventricular assist device (LVAD) and aortic graft angle on hemodynamics of aortic valve. Methods Three models of aorta and aortic valve with 45°, 60° and 90° anastomosis angles between LVAD and aorta were constructed, and an in vitro pulsating table was built for in vitro experiments. Using particle image velocimetry (PIV) system, three moments in the cardiac cycle ( T1 systolic peak, T rapid closure, T3 diastolic peak), were selected to study the hemodynamic state of aortic valve. Results Velocity vector, vorticity and viscous shear stress were used to evaluate the effect of LVAD anastomosis angle on hemodynamics of aortic valve. During the period of rapid valve closure, with the increase of graft angle, the blood flow velocity near the valve wall, the average vorticity and the maximum viscous shear stress all increased. Conclusions When the graft angle is lower, the impact velocity of blood on the valve is smaller, and the shear force on the valve decreases, so that the valve is in a better hemodynamic environment. This study provides references for the selection of anastomotic angles in clinical operations.

In Vitro Experimental Study on Hemodynamics of Transcatheter Aortic Valve Replacement / 中国医疗器械杂志

The patient-specific aortic silicone model was established based on CTA data. The digital particle image velocimetry (DPIV) test method in the modified ViVitro pulsatile flow system was used to investigate the aortic hemodynamic performance and flow field characteristics before and after transcatheter aortic valve replacement (TAVR). The results showed that the hemodynamic parameters were consistent with the clinical data, which verified the accuracy of the model. From the comparative study of preoperative and postoperative effective orifice area (0.33 cm2 and 1.78 cm2), mean pressure difference (58 mmHg and 9 mmHg), percentage of regurgitation (52% and 8%), peak flow velocity (4.60 m/s and 1.81 m/s) and flow field distribution (eccentric jet and uniform jet), the immediate efficacy after TAVR is good. From the perspective of viscous shear stress and Reynolds shear stress, the risk of hemolysis and thrombotic problems was low in preoperative and postoperative patient-specific models. This study provides a set of reliable DPIV testing methods for aortic flow field, and provides biomechanical basis for the immediate and long-term effectiveness of TAVR from the perspective of hemodynamics and flow field characteristics. It has important application value in clinical diagnosis, surgical treatment and long-term evaluation.

Research Progress of Micro-PIV in Biomedical Engineering Field / 医用生物力学

Blood is an important component of living organism which is responsible for material transportation. The microenvironment of blood flow plays an important role in physiological and pathological processes of angiogenesis and cardiac development, erythrocytes aggregation and blood viscosity, tumor metastasis and atherosclerosis. Besides, micro-fluid environment significantly affects drug delivery, cell screening, and artificial organ design. Thus, the measurement and quantitative analysis of micro-fluid contribute to the biomedical engineering filed. Micro-particle imaging velocimetry (Micro-PIV) combines conventional PIV with microscopy technique. Correlation analysis is conducted in two groups of images captured by high speed camera at different time intervals, and the velocity profiles in micro-fluid environment are successfully measured. Compared with other velocity measurement methods, Micro-PIV has high temporal resolution and spatial resolution. The main setup of Micro-PIV and its principle analysis method were introduced in this review. Recent studies of Micro-PIV applications in biomedical engineering field were then summarized. Moreover, the drawbacks of Micro-PIV technique and prospect of its applications were discussed.

Uterine Artery Doppler Screening in 2nd Trimester of Pregnancy for Prediction of Pre-eclampsia and Fetal Growth Restriction

Background: Pre-eclampsia is a pregnancy specific disorder characterized by hypertension and proteinuria after 20 weeks of gestation. Uterine artery Doppler velocimetry analysis has been extensively studied in the second trimester of pregnancy as a predictive investigation for the future development of pre-eclampsia and Fetal Growth Restriction.Aims: To predict the probability of developing pre-eclampsia of pregnant women and Fetal Growth Restriction in relation with normal and abnormal Doppler velocimetry of uterine artery at 2nd trimester of pregnancy.Methods:A total of 97 pregnant women of 2nd trimester of pregnancy were included in this study After taking informed written consent of the participants, all they underwent uterine artery Doppler velocimetry at 22ndand 24thweek of pregnancy. They again examined clinically during delivery at different gestational age. Pre-eclampsia (PE) was diagnosed on the basis of measurement of blood pressure as well as urine routine and microscopic examination. Fetal Growth Restriction (FGR) was determined by measuring birth weight and gestational age at the time of delivery. Development of PE and FGR was observed in relation to severity of Uterine Artery Doppler Velocimetry findings. A pre-structured data collection sheet was used as a research tool for data collection. Statistical analyses of the results were obtained by using windows-based computer software devised with Statistical Packages for Social Sciences (SPSS-23).Results: More than half (52.6%) of the subjects belonged to age 21-25 years and 52(53.6%) subjects were nulliparous. More than half (56.7%) of the subjects came from low income group family. Pre-eclampsia developed 11(11.3%) of the patients, 15(15.5%) had FGR and 12(12.4%) had notching in 2ndUADV at 24thweek. Presence of Pre-diastolic notch in 2ndUADV study at 24thweek to predict pre-eclampsia has sensitivity 72.7%, specificity 95.4%, accuracy 92.8% and positive predictive values 66.7% and negative predictive value 96.5%. Presence of Pre-diastolic notch in 2ndUADV study at 24thweek to predict FGR has sensitivity 20.0%, specificity 89.0%, accuracy 78.4% and positive predictive values 25.0% and negative predictive value 85.9%. The mean age was 28.69±7.81 years who had per-diastolic notch in 2ndUADV at 24thweek and 24.13±6.11 years who had normal UADV and the p value is 0.022 which is significant. The mean para was 1.29±0.33 who had per-diastolic notch in 2ndUADV at 24thweek and 1.77±0.29 who had normal UADV together with remarkable p value which is 0.001. The mean BMI was 23.59±1.09 Kg/m2who had per-diastolic notch in 2ndUADV at 24thweek and 21.57±0.47 Kg/m2who had normal UADV with notable p value 0.001 in this study.Conclusion:Uterine artery Doppler velocimetry in early pregnancy can be a good investigating tool for prediction of subsequent development of pre-eclampsia and Fetal Growth Restriction

Aortic isthmus doppler velocimetry in fetuses with intrauterine growth restriction: A literature review / Dopplervelocimetria do istmo aórtico em fetos com crescimento intrauterino restrito: Uma revisão da literatura

Abstract Intrauterine growth restriction (IUGR) is associated with poor perinatal prognosis and a higher risk of stillbirth, neonatal death, and cerebral palsy. Its detection and the evaluation of its severity by new Doppler velocimetric parameters, such as aortic isthmus (AoI), are of great relevance for obstetrical practice. The AoI is a vascular segment that represents a point of communication between the right and left fetal circulations. It is considered to be a functional arterial shunt that reflects the relationship between the systemic and cerebral impedances, and has recently been proposed as a tool to detect the status of hemodynamic balance and prognosis of IUGR in fetuses. In the present review, we noticed that in healthy fetuses, the AoI net flow is always antegrade, but in fetuses with IUGR the deterioration of placental function leads to progressive reduction in its flow until it becomes mostly retrograde; this point is associated with a drastic reduction in oxygen delivery to the brain. The more impaired the AoI flow is, the greater is the risk of impairment in the Doppler velocimetry of other vessels; and the alterations of the AoI Doppler seem to precede other indicators of severe hypoxemia. Although there seems to be an association between the presence of retrograde flow in the AoI and the risk of long-term neurologic disability, its role in the prediction of perinatal morbi-mortality remains unclear. The AoI Doppler seems to be a promising tool in the management of fetuses with IUGR, but more studies are needed to investigate its employment in clinical practice.

Resumo O crescimento intrauterino restrito (CIUR) está associado a um prognóstico perinatal adverso, com maior risco de óbito intrauterino e neonatal, bem como de paralisia cerebral. Assim, sua detecção e a determinação de sua gravidade por novos parâmetros Dopplervelocimétricos, como o istmo aórtico (IAo), são de fundamental importância na prática obstétrica. O IAo é um segmento vascular que representa um ponto de comunicação entre os sistemas circulatórios fetais esquerdo e direito. É considerado um shunt arterial funcional, capaz de refletir a relação entre as impedâncias dos circuitos cerebral e sistêmico, e foi proposto como uma ferramenta para detecção do status do equilíbrio hemodinâmico e do prognóstico de fetos com CIUR. Na presente revisão, observou-se que, em fetos saudáveis, o fluxo predominante no IAo é sempre anterógrado; mas em fetos com CIUR a deterioração do estágio de insuficiência placentária acarreta reduções progressivas no fluxo ístmico até este apresentar sentido predominantemente retrógrado e levar a uma drástica redução no aporte de oxigênio ao sistema nervoso central. Quanto mais alterado estiver o fluxo no IAo, maior a chance de haver alteração na Dopplervelocimetria de outros vasos; e as alterações no Doppler do IAo parecem preceder outros indicadores de hipoxemia severa. Embora o fluxo retrógrado no IAo pareça se correlacionar com maior risco de alteração no desenvolvimento neurológico a longo prazo, ainda não está claro o seu papel na predição de morbimortalidade perinatal. O Doppler do IAo parece ser um parâmetro promissor no manejo do CIUR; entretanto, mais estudos são necessários para avaliar seu emprego na prática clínica.

Study of fetal doppler velocimetry versus non stress test as predictors of adverse perinatal outcome in high risk pregnancies

Background: Pregnancy is a unique, physiologically normal event in a women’s life. Objective of this study was to compare the efficacy of the doppler velocimetry versus non stress test in relation to perinatal outcome in high risk pregnancies.Methods: This is a prospective study conducted in the department of obstetrics and gynaecology, Narayana Medical College and Hospital. 100 women with high risk pregnancy were recruited. All were examined systematically, and Doppler velocimetry and non-stress test were done.Results: All cases were divided into four groups based on NST and doppler velocimetry of umbilical artery and middle cerebral artery. 10% of women had abnormal doppler. Middle cerebral artery doppler abnormality was noted in 3% and CPR abnormality in 3% of women in the study group. 15% had abnormal NST. In Group A, out of 88 patients 9 had fetal compromise. In Group B, out of 5 patients all had fetal compromise. In Group C, out of 4 patients none had fetal compromise. In Group D, all 3 patients had fetal compromise. In Group D, all 3 had neonatal deaths. Average birth weights in Group A was 2.7 kg, in Group B was 2 kg, in Group C was 2.5 kg, in Group D was 1.4 kg. Two (2.2%) newborn in Group A, 4 (80%) newborns in Group B, 3 (100%) in Group had Apgar < 7 at 5 minutes. 4 (4.5%) babies in Group A, 5 (100%) babies in Group B, 3 (100%) babies in Group D were admitted in NICU. Umbilical artery doppler was found to have sensitivity 46.6%, specificity - 94%, PPV - 93%, NPV - 54%. Middle cerebral artery doppler was found to have sensitivity 73.3%, specificity - 90%, PPV - 91.6%, NPV- 69.3%.Conclusions: In present study, highest percentage of perinatal complications and perinatal deaths were seen in groups with abnormal tests of NST and velocimetry. Group D had the worst perinatal outcome.

Modelo predictivo de restricción del crecimiento intrauterino usando doppler de arterias uterinas y edad materna / Predictive model of intrauterine growth restriction using uterine artery doppler and maternal age

INTRODUCCIÓN: La restricción del crecimiento intrauterino representa una importante morbimortalidad perinatal y cuya detección es variable según modelos clínicos y características propias en cada población. OBJETIVO: Evaluar si el Doppler de arterias uterinas y la edad materna conforman un modelo clínico con capacidad predictiva de restricción del crecimiento intrauterino en una amplia muestra de población peruana. MATERIALES Y MÉTODOS: Estudio observacional, analítico, de prueba diagnóstica. Participaron 1344 gestantes atendidas en un centro de referencia nacional materno perinatal Nivel III en Perú entre 2010-2018. La muestra fue seleccionada aleatoriamente y dividida en: muestra de entrenamiento y muestra para validación del mejor modelo clínico obtenido. Se usó análisis multivariado, medición de la capacidad diagnóstica y predictiva. RESULTADOS: El modelo clínico formado por el índice de pulsatilidad promedio mayor al percentil 95 de la arteria uterina y la edad materna mayor a 35 años conformo el modelo con el menor indicador de penalidad de Akaike en comparación con los otros modelos clínicos elaborados en el presente estudio, el índice de Youden fue 0.53. El área bajo la curva ROC fue de 0.75. Se obtuvo una sensibilidad de 71.5%, especificidad 72.1%, valor predictivo positivo 65.8%, valor predictivo negativo 91.2%. CONCLUSIONES: El uso del índice de pulsatilidad promedio de la arteria uterina asociado a la edad materna contribuyen a la formación de un modelo para discriminar RCIU; sin embargo, requiere de otros factores que permitan ajustar el modelo para una mayor tasa de detección.

INTRODUCTION: Intrauterine growth restriction represents an important perinatal morbimortality and its detection varies according to clinical models and characteristics of each population. OBJECTIVES: To evaluate if uterine artery Doppler and maternal age conform a clinical model with predictive capacity of intrauterine growth restriction in a wide sample of Peruvian population. MATERIALS AND METHOD: Observational, analytical, diagnostic test study. A total of 1344 pregnant women attended a national maternal perinatal reference center Level III in Peru between 2010-2018. The sample was randomly selected and divided: training sample and validation sample. In the analysis, multivariate analysis and measurement of diagnostic and predictive capabilities were applied. RESULTS: The clinical model formed by the average pulsatility index greater than the 95th percentile of the uterine artery and maternal age greater than 35 years made up the model with the lowest Akaike's penalty indicator compared to the other clinical models developed in the present study, Youden's index was 0.53. The area under the ROC curve 0.75. Sensitivity 71.5%, specificity 72.1%, positive predictive value 65.8%, negative predictive value 91.2%. CONCLUSIONS: The use of the average pulsatility index of the uterine artery associated with maternal age contributes to the formation of a model to discriminate IUGR; however, it requires other factors to adjust the model for a higher detection rate.

A prospective study on the role of umbilical artery doppler velocimetry in the perinatal outcome of growth restricted fetuses

Background: To compare pregnancy outcomes in growth-restricted fetuses retaining normal umbilical artery doppler flow and the outcomes of pregnancies with end-diastolic velocity diminished or severely reduced/absent.Methods: In a prospective observational study, one hundred pregnant women with growth-restricted fetuses were followed with doppler velocimetry of the umbilical artery between weeks 28 and 41 of pregnancy. Outcomes were compared for the normal doppler group (55%) (Group 1), the low-end diastolic flow group (32%) (Group 2), and the group with severely reduced or absent end-diastolic velocity waveforms (13%) (Group 3).Results: Fetuses with abnormal umbilical flow velocimetry had higher incidence of oligohydramnios (82.2%). The average birth weight and gestational age at delivery were lower in the abnormal doppler group. Significantly more women with severe reduction/AEDV, 31/45 (68.8%), underwent caesarean section, with 20 of them (44.4 %) for fetal distress, compared with 17/55 (30.9%) women in the normal doppler group, with 9 of them (16.4%) for fetal distress. Also, fetuses with abnormal umbilical artery velocimetry had early delivery at less than 36 weeks of gestation (38.2% versus 65.85%), increased NICU admission (32.7% versus 80%), need for PPV (5.5% versus 40%), low Apgar score (9.1 % versus 50.2%) than those with normal doppler. All the three stillbirths in the study population were in the abnormal doppler group.Conclusions: Umbilical artery doppler velocimetry helps in differentiating fetus with pathological growth restriction at risk for perinatal complications from small and healthy fetuses.

Comparative performance of Cerebral Perfusion Ratio as compared to MCA PI and UA PI in prediction of adverse perinatal outcomes in intra uterine growth restricted fetuses

Background: Intra uterine growth restriction (IUGR) is a common clinical sign seen due to chronic foetal hypoxemia and is considered a major contributor of perinatal morbidity and mortality. The aim of the present study was to determine and compare the sensitivity and specificity of umbilical artery pulsatility index (UA PI), middle cerebral artery (MCA) PI and cerebral perfusion ratio (CPR) in predicting adverse and poor perinatal outcomes in fetuses with IUGR.Methods: The study included 100 pregnant women with post 24 weeks of gestation with clinical history of IUGR.  Doppler examination parameters, including waveforms and measurements, of the umbilical artery, middle cerebral artery were recorded. The Cerebral Perfusion Ratio (CPR) was calculated from MCA PI and UA PI and a final comparison of accuracy of Doppler indices was done with perinatal outcome.Results: The sensitivity of the UA PI was higher (49.3%) than that of the MCA PI (43.6%) and the CPR (37.7%). The specificity of the CPR was higher (87.1%) than that of the MCA PI (83.9%) and the UA PI (74.2%).Conclusions: From the findings of the study, it can be concluded that UA PI is the most sensitive and CPR is the most specific parameter in predicting adverse perinatal outcomes in IUGR fetuses. Thus, in addition to pulsatility indices, CPR should be used as a tool for surveillance and included in the routine reporting formats of obstetric Doppler studies.

Efficacy of doppler velocimetry of the umbilical artery in the defined high-risk groups to determine the fetal outcome

Background: Doppler ultrasound provides a non-invasive method of studying the status of various blood vessels. It provides a spectrum analysis of the velocities of moving red blood cells. Doppler sonography can provide useful information in a variety of gynecological and obstetric conditions. In obstetrics, Doppler velocimetry of the uteroplacental and fetoplacental circulation can be used to further investigate complications of pregnancy such as fetal growth restriction, other forms of fetal distress that result from fetal hypoxemia or asphyxia.Methods: In a prospective observational study, 93 pregnancies fitting in the criteria for high risk were evaluated by doppler velocimetry between 28-40 weeks of gestation. The flow velocity time wave forms were examined and quantitated by use of systolic/diastolic (S/D) ratio, resistance index (RI), pulsatility index (PI) values. The outcome of pregnancy was noted.Results: Fetuses with abnormal velocimetry are at higher risk with regard to birth weight, Apgar score, fetal distress, need of cesarean section, need of NICU admission. The patients with absent end-diastolic flow (AEDF)/reversal of end-diastolic flow (REDF) had poor perinatal outcome. Positive predictive value for small for gestational age (SGA) and fetal distress was 75% and 60% respectively. 23.8% babies needed to be kept in neonatal intensive care unit (NICU).Conclusions: Doppler velocimetry can be useful prenatal test for the patients of hypertensive disorder of pregnancy and IUGR. Abnormal doppler waveform changes indicate adverse perinatal outcome. Appropriate and timely interventions guided by doppler study help to reduce perinatal morbidity and mortality.

Biometric, B-mode and color Doppler ultrasound assessment of eyes in healthy dogs / Avaliação biométrica, ultrassonográfica em modo-B e por Doppler colorido ocular de cães hígidos

B-scan ultrasonography is an important diagnostic tool that allows characterization of internal organ anatomy and, when complemented by Doppler ultrasound, allows vascular hemodynamic assessment, increasing the diagnostic accuracy. Thus, the aim of the present study was the B-scan ultrasound characterization and measurement of the eyeball segments and assessment of the external ophthalmic artery by color and pulsed Doppler. Sixty eyeballs were assessed from 30 dogs of different breeds using an 8.5MHz microconvex transductor. First, biometry was performed by B-scan of the following segments: axial length (M1), anterior chamber depth (M2), lens thickness (M3), lens length (M4), vitreous chamber depth (M5), optical disc length (M6) and optic nerve diameter (M7). Colored Doppler identified the external ophthalmic article and pulsed Doppler assessed its flow, and the following were measured: systolic peak velocity (VPS), final diastolic velocity (VDF), resistivity index (IR) and pulse index (IP). No statistical difference was observed for the biometric values of the eye segments between the right and left eyes (p>0.05). The vitreous chamber depth (M5) was shown to be the biometric variable with greatest bilateral symmetry, varying from 0.79 to 0.87cm and 0.78 to 0.86cm for the right and left eye, respectively. The ophthalmic artery was visualized over the optic nerve towards the eyeball, with flow stained red. There was no significant statistical difference between the Doppler velocimetric values for the ophthalmic artery between the right and left eye of the animals assessed (p>0.05). The mean resistivity index (RI) showed average values equal to 0.63±0.03, bilaterally. The mean base velocity was 17.50cm/s and 18.18cm/s at the systolic peak and 6.21cm/s and 6.68cm/s at the end of the diastole, for the right and left eyes respectively. The anatomic, biometric and hemodynamic characterization using the ultrasound B-scan and the Doppler modalities permitted the ultrasonographic and Doppler velocimetric assessment of the eyeball components in dogs of different breeds, and it can be used in ophthalmic clinical routine to identify eye pathologies.

O exame ultrassonográfico modo-B é uma importante ferramenta diagnóstica que permite caracterizar a anatomia interna dos órgãos e, complementada pelo exame modo Doppler, possibilita realizar a avaliação hemodinâmica vascular, aumentando a acurácia diagnóstica. Desta forma, este trabalho teve como objetivo a caracterização ultrassonográfica e mensuração dos segmentos do bulbo ocular modo-B, assim como a avaliação da artéria oftálmica externa pelo Doppler colorido e pulsado. Foram avaliados 60 bulbos oculares de 30 cães de diferentes raças utilizando transdutor microconvexo de 8,5MHz. Inicialmente foi realizada biometria por meio do exame em modo-B dos seguintes seguimentos: comprimento axial (M1), profundidade da câmara anterior (M2), espessura da lente (M3), comprimento da lente (M4), profundidade da câmara vítrea (M5), comprimento do disco óptico (M6) e diâmetro do nervo óptico (M7). A artéria oftálmica externa foi identificada pelo Doppler colorido e seu fluxo foi avaliado por meio do Doppler pulsado, sendo mensurados: velocidade do pico sistólico (VPS), velocidade diastólica final (VDF), índice de resistividade (IR) e índice de pulsatilidade (IP). Não foi verificada diferença estatística para os valores biométricos dos seguimentos oculares entre os olhos direito e esquerdo (p>0,05). A profundidade da câmera vítrea (M5), mostrou-se a variável biométrica com maior simetria bilateral, variando entre 0,79 a 0,87cm e 0,78 a 0,86cm para o olho direito e esquerdo, respectivamente. A artéria oftálmica foi visibilizada sobre o nervo óptico em direção ao bulbo ocular, com fluxo marcado em vermelho. Não houve diferença estatística significativa entre os valores Dopplervelocimétricos da artéria oftálmica entre do olho direito e esquerdo dos animais avaliados (p>0.05). O índice de resistividade (IR) médio evidenciou valores médios sendo igual a 0,63±0,03, bilateralmente. A velocidade basal média foi 17,50cm/s e 18,18cm/s no pico sistólico e 6,21cm/s e 6,68cm/s no final da diástole, para os olhos direito e esquerdo, respectivamente. A caracterização anatômica, biométrica e hemodinâmica utilizando o exame ultrassonográfico modo-B e as modalidades do Doppler permitiram a avaliação ultrassonográfica e Dopplervelocimétrica dos componentes do bulbo ocular nos cães de diferentes raças, podendo ser utilizados na rotina clínica oftalmológica para identificação de patologias oculares.

Uterine artery Doppler flow velocimetry parameters for predicting gestational trophoblastic neoplasia after complete hydatidiform mole, a prospective cohort study

OBJECTIVES: Doppler ultrasonography can be used to assess neoangiogenesis, a characteristic feature of postmolar gestational trophoblastic neoplasia. However, there is limited information on whether uterine artery Doppler flow velocimetry parameters can predict gestational trophoblastic neoplasia following a complete hydatidiform mole. The purpose of this study was as follows: 1) to compare uterine blood flow before and after complete mole evacuation between women who developed postmolar gestational trophoblastic neoplasia and those who achieved spontaneous remission, 2) to assess the usefulness of uterine Doppler parameters as predictors of postmolar gestational trophoblastic neoplasia and to determine the best parameters and cutoff values for predicting postmolar gestational trophoblastic neoplasia. METHODS: This prospective cohort study included 246 patients with a complete mole who were treated at three different trophoblastic diseases centers between 2013 and 2014. The pulsatility index, resistivity index, and systolic/diastolic ratio were measured by Doppler flow velocimetry before and 4-6 weeks after molar evacuation. Statistical analysis was performed using Wilcoxon’s test, logistic regression, and ROC analysis. RESULTS: No differences in pre- and post-evacuation Doppler measurements were observed in patients who developed postmolar gestational trophoblastic neoplasia. In those with spontaneous remission, the pulsatility index and systolic/diastolic ratio were increased after evacuation. The pre- and post-evacuation pulsatility indices were significantly lower in patients with gestational trophoblastic neoplasia (odds ratio of 13.9-30.5). A pre-evacuation pulsatility index ≤1.38 (77% sensitivity and 82% specificity) and post-evacuation pulsatility index ≤1.77 (79% sensitivity and 86% specificity) were significantly predictive of gestational trophoblastic neoplasia. CONCLUSIONS: Uterine Doppler flow velocimetry measurements, particularly pre- and post-molar evacuation pulsatility indices, can be useful for predicting postmolar gestational trophoblastic neoplasia.

Clinical application of electrical velocimetry in monitoring pediatric blood volume after cardiopulmonary bypass / 中华儿科杂志

Objective@#To investigate the clinical applicability of electrical velocimetry (EV) in monitoring pediatric blood volume after cardiopulmonary bypass.@*Method@#Between July 2016 and November 2016, 60 children with congenital heart disease were divided into EV group and traditional central venous pressure (CVP) group randomly. For EV group, the volume of fluid and vascular active medicine was adjusted according to the monitoring stroke volume variation (SVV) hemodynamic parameters. Whereas for CVP group empirical volume of fluid infusion was managed by the monitoring traditional hemodynamic parameters such as CVP, blood pressure, heart rate, urine volume and blood gas analysis.Heart rate (HR), mean artery pressure (MAP), blood lactic acid (LA), oxygenation index (PaO2/FiO2) at 2, 4 and 6 h after operation were observed and compared between two groups. Mechanical ventilation time and ICU monitoring time were also compared between two groups. Pearson correlation analysis was performed to investigate the significance of SVV and inferior vena cava expansion index (dIVC) for evaluating of reactivity capacity after surgery.@*Result@#MAP level was significantly higher in EV group at 2, 4, and 6 h after operation [ (62±10) vs. (50±6) mmHg(1 mmHg=0.133 kPa), (68±11) vs.(59±4) mmHg, (71±6) vs. (63±8) mmHg respectively; t=5.580 9, 4.530 1, 4.308 1; P=0.001, 0.002, 0.001]. PaO2/FiO2 ratio was higher in EV group than that of CVP group[ (362±23) vs. (310±43), (380±33) vs. (330±38), (386±57) vs. (350±63.1) respectively, t=5.818 8, 5.419 2, 2.317 2; P=0.002, 0.001, 0.024]. However HR and blood lactic acid level was lower in EV group than the CVP group [(166±10) vs. (179±14)/min, (156±11) vs. (168±16)/min, (138±10) vs. (149±13)/min respectively; t=3.930 7, 3.511 1, 3.671 5; P=0.002, 0.009, 0.005]; [7% vs. 33%, 3% vs. 20%, 0 vs. 13%, χ2=5.104 2、4.043 1、4.285 7, P=0.045 3, 0.044 4, 0.038 4] respectively; Mechanical ventilation time [ (4.3±0.7) vs. (8.2±0.8) h, P=0.008] and ICU monitoring time [ (16.4±3.2) vs. (21.2±2.6) h,P=0.003] was shorter in EV group than that in group CVP. Pearson correlation analysis suggested that the SVV and dIVC have significant positive correlation.@*Conclusion@#SVV monitoring using EV could help to guide perioperative fluid management for children with congenital heart disease. Real time dynamic monitoring SVV improves liquid infusion management more timely, accurately, and avoids excessive or insufficient blood volume load which is associated with leading to organ dysfunction.

Comparison of speed of inhalational induction in children with and without congenital heart disease.

Background: Conduct of stable inhalational anesthetic induction in children with congenital heart disease (CHD) presents special challenges. It requires in‑depth understanding of the effect of congenital shunt lesions on the uptake, delivery, and equilibration of anesthetic drugs. Intracardiac shunts can alter the induction time and if delivery of anesthetic agent is not carefully titrated, can lead to overdosing and undesirable myocardial depression. Aims: To study the effect of congenital shunt lesions on the speed of inhalational induction and also the impact of inhalational induction on hemodynamics in the presence of congenital shunt lesions. Setting: Tertiary care hospital. Design: A prospective, single‑center clinical study. Materials and Methods: Ninety‑three pediatric patients undergoing elective surgery were segregated into three equal groups, namely, Group 1: no CHD, Group 2: acyanotic CHD, and Group 3: cyanotic CHD. General anesthesia was induced with 8% sevoflurane in 6 L/min air‑oxygen. The time to induction was noted at loss of eyelash reflex and decrease in bispectral index (BIS) value below 60. End‑tidal sevoflurane concentration, minimum alveolar concentration, and BIS were recorded at 15 s intervals for the 1st min followed by 30 s interval for another 1 min during induction. Hemodynamic data were recorded before and after induction. Results: Patients in Group 3 had significantly prolonged induction time (99 ± 12.3 s; P < 0.001), almost twice that of the patients in other two groups (51 ± 11.3 s in Group 1 and 53 ± 12.0 s in Group 2). Hypotension occurred after induction in Group 1. No other adverse hemodynamic perturbations were observed. Conclusion: The time to inhalational induction of anesthesia is significantly prolonged in patients with right‑to‑left shunt, compared to patients without CHD or those with left‑to‑right shunt, in whom it is similar. Sevoflurane is safe and maintains stable hemodynamics in the presence of CHD.

Placental mesenchymal dysplasia and intrauterine fetal growth restriction with doppler velocimetry alterations: a case report

Placental mesenchymal dysplasia (PMD) is a rare placental abnormality. We report a case of PMD associated with intrauterine growth restriction (IUGR), which was diagnosed by an ultrasound scan during the second trimester of pregnancy. A 36-year-old primiparous woman with signs of placental chorioangioma was referred to our hospital at the 23th gestational week. An ultrasonography revealed a small-for-gestational-age fetus with a large multicystic placenta. A serial Doppler sonographic assessment of umbilical and uterine artery blood flow showed a compromised fetus. A female, small-for-gestational-age baby was delivered by c-section at 28 weeks, and PMD was histopathologically confirmed

The Influence of Incudostapedial Joint Separation on the Middle Ear Transfer Function

OBJECTIVES: One of the risks in middle ear surgery is high frequency hearing loss. It is believed that manipulations on the middle ear ossicles with the instruments may cause overstimulation of the inner ear and damage of the hear cells. Controversy arises whether temporary separation of the ossicles has any impact on middle ear transfer function and hearing threshold after surgery. The aim of the study is to evaluate the influence of incudostapedial joint (ISJ) separation on middle ear function in an experimental model. METHODS: With the use of single point laser Doppler vibrometer (LDV) stapes velocity in the intact chain and after ISJ separation was measured in 5 fresh human cadaver temporal bones. RESULTS: In all cases there was a decrease in stapes velocity after ISJ separation. Mead stapes velocity was reduced for 1 dB in 800 Hz to 9 dB in frequencies above 1,000 Hz. The decrease of velocity was greater in higher frequencies. CONCLUSION: Separation of the ISJ does not reduce significantly the middle ear function.

Modificaciones en el flujo sanguíneo del tronco de la arteria pulmonar en fetos prematuros que recibieron corticoides

Objetivos: Evaluar las modificaciones de la velocimetría Doppler en el flujo sanguíneo del tronco de la arteria pulmonar en fetos prematuros expuestos a corticoesteroides. Diseño: Estudio prospectivo. Institución: Instituto Latinoamericano de Salud reproductiva (ILSAR), Lima, Perú. Participantes: Madres con 29 a 36 semanas de edad gestacional y sus fetos. Intervenciones: En gestantes con 29 a 36 semanas de gestación que habían recibido corticoides para madurez pulmonar fetal, se hizo velocimetría Doppler del flujo sanguíneo del tronco de la arteria pulmonar de sus fetos. Principales medidas de resultados: Correlación de los cambios de la velocimetría Doppler con la madurez pulmonar en el neonato. Resultados: Los fetos prematuros que recibieron corticoides no tuvieron complicaciones respiratorias neonatales cuando el índice tiempo de aceleración/tiempo de desaceleración sistólico (TA/TD) fue igual o mayor a 0,57, cuyo valor se alcanzó en fetos con 33 semanas o más y con peso desde 2 000 g. Los valores de TA/TD luego de corticoides tuvieron una correlación estadística alta con las complicaciones respiratorias del RN (p<0,0001). Conclusiones: Después de aplicar corticoides para madurar el pulmón en fetos prematuros, se observó modificaciones en el flujo del tronco de la arteria pulmonar medidos con el índice TA/TD, con valores superiores a los observados para la misma edad gestacional en fetos sin corticoides. La diferencia fue altamente significativa desde la semana 33. El índice TA/TD del tronco de la arteria pulmonar es una herramienta útil para determinar madurez pulmonar.

Objectives: To determine changes in pulmonary artery blood flow Doppler velocimetry in preterm fetuses exposed to corticosteroids. Design: Prospective study. Setting: Instituto Latinoamericano de Salud Reproductiva (ILSAR), Lima, Peru. Participants: Mothers 29-36 weeks of gestation and their fetuses. Interventions: In fetuses of mothers 29-36 weeks of gestation who had received corticosteroids for maturation pulmonary artery blood flow Doppler velocimetry was performed. Main outcome measures: Correlation of Doppler velocimetry changes and neonate lung maturity. Results: Preterm fetuses that received corticosteroids did not present neonatal respiratory complications when systolic acceleration time/deceleration time (AT/DT) index was equal or over 0,57, value obtained in fetuses 33 weeks or more and weight over 2 000 g. AT/DT values following corticosteroids showed high statistical correlation with newborn respiratory complications (p<0,0001). Conclusions: Pulmonary artery blood flow measured with AT/DT index was modified after corticosteroids administration for preterm fetal lung maturation; values were superior to those observed for same gestational age fetuses without corticosteroids. Difference was highly significant starting at week 33. AT/DT index of the pulmonary artery stem is a useful tool to determine pulmonary maturity.

PIV experiment on flow fields of the real human upper respiratory tract gauge model / 医用生物力学

Objective To investigate the airflow distribution mode in human upper respiratory tract model for understanding the characteristics of the airflow in human upper respiratory tract, and provide scientific basis for analyzing the diffusion, transition and deposition patterns of aerosol in human upper respiratory tract. Methods PIV（particle image velocimetry）technology was adopted to study flow fields of the real human upper respiratory tract model. The airflow state in oral cavity，pharynx and trachea was analyzed. Results The flow velocity was relatively high at the upper tongue coating and in the middle of the oral cavity; when the airflow reached the pharynx, the velocity was increased rapidly due to the reduction of sectional area; the maximum velocity (10.24 m/s) appeared in the glottis, and the velocity in the anterior wall was higher than that in the posterior wall of the trachea; as the airflow injected at the glottis, the velocity gradient was increased, and the vorticity was concentrated at the anterior and posterior wall of the glottis, resulting in a significantly higher vorticity value at anterior wall of the trachea than that at the posterior wall. Conclusions PIV technology is an effective way to investigate the airflow distribution mode in human upper respiratory tract, and it is of great importance for exploring the harm of toxic aerosol to human body and the therapeutic effect of inhalation drug aerosol, as well as for researching the pathogenesis of respiratory system.

Numerical and experimental study on steady flow in the model of internal carotid artery siphon / 医用生物力学

Objective To investigate the hemodynamic factors in internal carotid arteries (ICA) with different shapes, and analyze the relationship between the arterial geometry and atherosclerotic stenosis to provide the hemodyanmic basis for the risk prediction and early diagnosis of ICA stenosis. Methods The flow field in the most two common types of ICAs, U and V-shaped ICA, were investigated by numerical simulation and particle image velocimetry (PIV) experiment under the condition of steady flow. Results At the upstream bend of ICA, the hemodynamic factors were monotonically associated with the curvature of the bend. As a result, the risk for stenosis here was smaller in the V-shaped ICA, as compared to U-shaped ICA. But at the downstream bend, such monotonic relationship didn’t exist due to the synergistic effect of the two bends. ConclusionsThe curvature of the artery is positively related to the risk for stenosis, but the synergistic effect of bends needs to be considered for studying arteries with the serial bends. The research on the synergistic effect may explain why the stenosis is frequently observed in arteries with multiple bends.