Jacques Samson

A Novel Translational Model of Percutaneous Fetoscopic Endoluminal Tracheal Occlusion - Baboons (Papio spp.)

Introduction: Percutaneous fetoscopic endoluminal reversible tracheal occlusion (FETO) was developed to prevent the pulmonary complications of fetal congenital diaphragmatic herniation. There is an urgent need to establish the closest to human translational model of FETO in order to improve fetal outcomes and to determine new clinical approaches and applications. Material and Methods: Seven non-human primates underwent two subsequent surgeries: the first, the FETO in the experimental group (n = 3) or sham operation in the control animals (S-FETO, n = 4) at 132-142 days of gestation (dGA); the second, the reversal of occlusion or sham operation at 162 ± 5 dGA. Maternal stress axis, complete blood count, and biochemical parameters were evaluated and newborn tracheal radiography was performed. Results: The average pregnancy duration and neonatal weights in the FETO group did not differ from the animals in the S-FETO group. There was no bleeding or premature fetal membrane rupture during the procedures in any of the baboons. The maximal tracheal width was 7.02 ± 0.6 mm in the FETO versus 5.46 ± 0.6 mm in S-FETO group. Discussion: This is the very first report of a successful FETO model in non-human primates. Similarities to human tracheomegaly were for the first time documented in any model studied.

Predicting Fetal Lung Maturity Using the Fetal Pulmonary Artery Doppler Wave Acceleration/Ejection Time Ratio

Objective: To determine whether the acceleration/ejection time ratio of the fetal main pulmonary artery Doppler waveform (PATET) can accurately predict the results of fetal lung maturity testing in amniotic fluid. Methods: We prospectively studied pregnant women attending our ultrasound unit for clinically indicated fetal lung maturity testing. An ultrasound examination that included measurement of the PATET was performed before the results of the amniocentesis were reported. The results of the PATET and the surfactant/albumin ratio were compared, and a receiver operating characteristic curve was used to determine the PATET cutoff with the optimal sensitivity and specificity for predicting surfactant/albumin ratio results. p < 0.05 was considered statistically significant. Results: Forty-three patients were included in this study. The receiver operating characteristic curve demonstrated that a PATET cutoff of 0.3149 provided a specificity of 93% (95% CI 77-98%), a sensitivity of 73% (95% CI 48-89%), a negative predictive value of 87% (95% CI 70-95%), and a positive predictive value of 85% (95% CI 58-96%) for predicting immature surfactant/albumin ratio results. Conclusion: The PATET may provide a noninvasive means of determining fetal lung maturity with acceptable levels of sensitivity, specificity, and predictive values.

Abruptio placentae in the baboon (Papio spp.)

INTRODUCTION Placental abruption is a serious condition that increases perinatal morbidity and mortality. Clinical prevention and treatment options are limited, especially in human preterm deliveries. Knowledge of the mechanisms that keep the placenta in place during pregnancy is critical for developing strategies for the prevention of abruption. Failure of physiological transformation of spiral arteries has been described as a major contributing factor of the placental abruption development. Baboons (Papio spp.) share striking similarities with humans in regard to placental structure, utero-placental blood flow, and fetal development; however, the mode of trophoblast invasion is shallow in baboons. This fact prompted the hypothesis that the incidence of placental abruption will be increased in baboons compared to humans. MATERIAL AND METHODS Baboon placentas were collected between 2002 and 2008. Two independent veterinary pathologists evaluated the slides. A certified physician pathologist performed additional histology. RESULTS Placental abruption was diagnosed in 22 baboons among 2423 live births during the study period (0.9% prevalence). The most common clinical presentations were fetal demise and vaginal bleeding. The most common pathological findings were intraplacental hemorrhages with or without hematoma formation (86.4%). Other findings consisted of neutrophil infiltration (50%), decidual necrosis (22.7%), decidual vascular congestion and inflammation, villous congestion and retroplacental hemorrhage/hematoma (each 18.2%). These pathologic findings were the same for term and preterm deliveries. CONCLUSION This is the first systematic study of placental abruption in non-human primates, analyzing a large colony of baboons. Despite differences in trophoblast invasion, the clinical features observed in placental abruption affecting baboons resembled those reported in humans. The cluster of placental pathological findings in baboons also agreed with clinical reports, but the prevalence of these findings differed between baboons and humans. We discuss a mechanism of anti-abruption forces that offset shallow trophoblast invasion observed in baboons.

Middle cerebral artery Doppler for managing fetal anemia.

The measurement of the middle cerebral artery peak systolic velocity, a noninvasive technique, has become the standard for the diagnosis of fetal anemia. The middle cerebral artery peak systolic velocity is used because of its ease of measurement and its high sensitivity in predicting anemia. This diagnostic tool should only be used with fetuses at risk for anemia and in medical centers with adequate training in the technique.

Eclampsia Characteristics and Outcomes: A Comparison of Two Eras

Objective. To describe the trends in incidence, characteristics, and outcomes of women with eclampsia. Methods. We reviewed and abstracted data from medical records of all women diagnosed with eclampsia in our institution from August 1998 to April 2011. In addition to overall characteristics and outcomes, the cases were stratified by onset: antenatal versus postnatal and early (<32 weeks of gestation) versus late antenatal cases (≥32 weeks of gestation). Comparisons were made using chi-square, Fishers exact, Mann-Whitney U, and t-tests. A two-sided P < 0.05 was considered statistically significant. Results. We identified 87 eclampsia cases out of 59,388 deliveries; 62 cases were diagnosed before delivery, and 25 had a postnatal onset. Among the 62 antenatal cases, 41 were diagnosed before 32 weeks and 21 at or after 32 weeks of gestation. Antenatal cases had higher systolic (P = 0.03) and diastolic (P = 0.01) blood pressures, more abnormal dipstick-test proteinuria (P = 0.002), and lower platelet counts (P ≤ 0.001) than postnatal cases. Early eclampsia cases were complicated more often with HELLP syndrome than late eclampsia cases (P = 0.007). Conclusion. The occurrence of eclampsia has decreased over time. The earlier the onset is, the worse the outcome appears to be.

OP37.01: Angle based measurement of the acceleration/ejection phase ratio as a non‐invasive method for fetal lung maturity testing

Objectives: Several 2 and 3-dimensional techniques have been used to asses ovarian blood flow and vascularity. All have their advantages and limitations. Spatio-temporal image correlation (STIC) is a 4D method that combines 2D velocity information with 3D vascular maps to provide pulsatile volumetric data across the cardiac cycle. This study was designed to see if this technique could be used to reliably acquire and measure 4D power Doppler data from the whole ovary. Methods: Ten consecutive patients in the early follicular phase of their menstrual cycle were scanned as part of their routine workup before starting fertility treatment (Voluson E8, GE Healthcare). STIC was used by two observers to acquire 4D data from the whole ovary using standardized settings. Each observer acquired two STIC datasets resulting in 4 STIC acquisitions for each ovary. From each acquisition a selected image was analyzed twice by both observers. VOCAL was used to define the ovarian cortex and the histogram applied to generate the vascularity index (VI), flow index (FI) and vascularity flow index (VFI). SPSS was used to calculate intraclass correlation coefficients (ICC) and their 95% confidence intervals. Results: The reliability analysis showed a high level of agreement between the two observers for both data acquisition and analysis for all three indices. The ICCs (95% CI) were indicative of a high degree (> 0.9) of both inter and intra observer measurements. Conclusions: This is the first study to show that STIC can be reliably used to acquire and measure 4D power Doppler data from the whole ovary. Previous studies have been limited by the need to apply spherical sampling techniques which is associated with an obvious subjective selection bias. Further work is required to assess the clinical relevance of this technique but it offers a new way to assess whole organ flow in a standardized manner that is less dependent on machine settings and inter-subject variation.