A substantial proportion of female physicians have faced infertility or have regrets about family planning decisions and career decision-making. Combining a medical career with motherhood continues to pose challenges, meriting further investigation and targeted support.
Purpose The treatment of extreme prematurity remains an unsolved problem. We developed an artificial placenta (AP) based on extracorporeal life support (ECLS) that simulates the intrauterine environment and provides gas exchange without mechanical ventilation (MV), and compared it to the current standard of neonatal care. Methods Extremely premature lambs (110-120d; term=145d) were used. AP lambs (n=9) were cannulated (jugular drainage, umbilical vein reinfusion) for ECLS .Control lambs (n=7) were intubated, ventilated, given surfactant, and transitioned to high-frequency oscillatory ventilation. All lambs received parenteral nutrition, antibiotics, and steroids. Hemodynamics, blood gases, hemoglobin, and circuit flows were measured. Results Four premature lambs survived for 1 week on the AP; one survived 6 days. Adequate oxygenation and ventilation were provided by the AP. The MV lambs survived 2-8 hours. Each of these lambs experienced a transient improvement with surfactant, but developed progressive hypercapnea and hypoxia despite high airway pressures and HFOV. Conclusions Extremely premature lambs were supported for 1 week with the AP with hemodynamic stability and adequate gas exchange; mechanically ventilated lambs succumbed within 8 hours. Further studies will assess control of fetal circulation and organ maturation on the AP.
An artificial placenta (AP) utilizing extracorporeal life support (ECLS) could protect premature lungs from injury and promote continued development. Preterm lambs at estimated gestational age (EGA) 114–128 days (term = 145) were delivered by Caesarian section and managed in one of three groups: AP, mechanical ventilation (MV), or tissue control (TC). Artificial placenta lambs (114 days EGA, n = 3; 121 days, n = 5) underwent venovenous (VV)-ECLS with jugular drainage and umbilical vein reinfusion for 7 days, with a fluid-filled, occluded airway. Mechanical ventilation lambs (121 days, n = 5; 128 days, n = 5) underwent conventional MV until failure or maximum 48 hours. Tissue control lambs (114 days, n = 3; 121 days, n = 5; 128 days, n = 5) were sacrificed at delivery. At the conclusion of each experiment, lungs were procured and sectioned. Hematoxylin and eosin (H&E) slides were scored 0–4 in seven injury categories, which were summed for a total injury score. Slides were also immunostained for platelet-derived growth factor receptor (PDGFR)-α and α-actin; lung development was quantified by the area fraction of double-positive tips of secondary alveolar septa. Support duration of AP lambs was 163 ± 9 (mean ± SD) hours, 4 ± 3 for early MV lambs, and 40 ± 6 for late MV lambs. Total injury scores at 121 days were 1.7 ± 2.1 for AP vs. 5.5 ± 1.6 for MV (p = 0.02). Using immunofluorescence, double-positive tip area fraction at 121 days was 0.017 ± 0.011 in AP lungs compared with 0.003 ± 0.003 in MV lungs (p < 0.001) and 0.009 ± 0.005 in TC lungs. At 128 days, double-positive tip area fraction was 0.012 ± 0.007 in AP lungs compared with 0.004 ± 0.004 in MV lungs (p < 0.001) and 0.016 ± 0.009 in TC lungs. The AP is protective against lung injury and promotes lung development compared with mechanical ventilation in premature lambs.
An artificial placenta (AP) using venovenous extracorporeal life support (VV-ECLS) could represent a paradigm shift in the treatment of extremely premature infants. However, AP support could potentially alter cerebral oxygen delivery. We assessed cerebral perfusion in fetal lambs on AP support using near-infrared spectroscopy (NIRS) and carotid arterial flow (CAF). Fourteen premature lambs at estimated gestational age (EGA) 130 days (term = 145) underwent cannulation of the right jugular vein and umbilical vein with initiation of VV-ECLS. An ultrasonic flow probe was placed around the right carotid artery (CA), and a NIRS sensor was placed on the scalp. Lambs were not ventilated. CAF, percentage of regional oxygen saturation (rSO2) as measured by NIRS, hemodynamic data, and blood gases were collected at baseline (native placental support) and regularly during AP support. Fetal lambs were maintained on AP support for a mean of 55 ± 27 hours. Baseline rSO2 on native placental support was 40% ± 3%, compared with a mean rSO2 during AP support of 50% ± 11% (p = 0.027). Baseline CAF was 27.4 ± 5.4 ml/kg/min compared with an average CAF of 23.7 ± 7.7 ml/kg/min during AP support. Cerebral fractional tissue oxygen extraction (FTOE) correlated negatively with CAF (r = -0.382; p < 0.001) and mean arterial pressure (r = -0.425; p < 0.001). FTOE weakly correlated with systemic O2 saturation (r = 0.091; p = 0.017). Cerebral oxygenation and blood flow in premature lambs are maintained during support with an AP. Cerebral O2 extraction is inversely related to carotid flow and is weakly correlated with systemic O2 saturation.
Background: Extremely premature neonates suffer high morbidity and mortality. An artificial placenta (AP) using extracorporeal life support (ECLS) is a promising therapy. Objectives: We hypothesized that intratracheal perfluorocarbon (PFC) instillation during AP support would reduce lung injury and promote lung development relative to intratracheal amniotic fluid or crystalloid. Methods: Lambs at an estimated gestational age (EGA) 116–121 days (term 145 days) were placed on venovenous ECLS with jugular drainage and umbilical vein reinfusion and intubated. Airways were managed by the instillation of amniotic fluid and tracheal occlusion (TO; n = 4), or lactated Ringer’s (LR; n = 4) or perfluorodecalin (a PFC) without occlusion (n = 4). After 7 days, the animals were sacrificed. Early (EGA 116–121 days) and late (EGA 125–131 days) tissue control lambs were delivered and sacrificed. Lungs were formalin-inflated to 30 cm H2O and sectioned for histology. Injury was scored by an unbiased pathologist. Slides were immunostained for PDGFR-α and α-actin; development was quantified by the area fraction of double-positive tips. Surfactant protein-C (SP-C) concentration in bronchoalveolar lavage fluid was quantified using ELISA. Results: Total injury scores were lower in PFC lungs (1.8 ± 1.7) than in TO (6.5 ± 2.1; p = 0.01) and LR lungs (5.5 ± 2.4; p = 0.01). The area fraction of double-positive alveolar tips appeared higher in PFC lungs than in TO lungs (0.18 ± 0.007 vs. 0.008 ± 0.004; p = 0.07). SP-C concentration was higher in PFC lungs than in TO lungs (37.9 ± 7.6 vs. 20.0 ± 5.4 pg/mL; p = 0.005), and both early (12.4 ± 1.7 g/mL; p = 0.007) and late tissue control lungs (15.1 ± 5.0 pg/mL; p = 0.0008). Conclusion: During AP support, intratracheal PFC prevents lung injury and promotes normal lung development better than crystalloid or amniotic fluid with TO.
Prolonged normothermic ex-vivo heart perfusion (NEVHP) could transform cardiac transplantation. To help identify perfusate components that might enable long-term perfusion, we evaluated the effects of cross-circulated whole blood and cross-circulated plasma from a live paracorporeal animal on donor porcine hearts preserved via NEVHP. Standard perfusion (n=40) utilized red blood cell/plasma perfusate and Langendorf technique for a goal of 12 hours. Cross-circulation groups used a similar circuit with the addition of cross-circulated venous whole blood (XC-Blood; n=6) or cross-circulated filtered plasma (XC-Plasma; n=7) between a live paracorporeal pig under anesthesia and the perfusate reservoir. Data included oxygen metabolism, vascular resistance, lactate production, left ventricular function, myocardial electrical impedance, and histopathologic injury score. All cross-circulation hearts were successfully perfused for 12 hours, compared to 22 of 40 standard perfusion hearts (55%; p=0.002). Both cross-circulation groups demonstrated higher oxygen consumption and vascular resistance than standard hearts from hours 3–12. No significant differences were seen between XC-Blood and XC-Plasma hearts in any variable, including left ventricular dP/dT after 12 hours (1478±700mmHg/s vs. 872±500; p=0.17). We conclude that cross circulation of whole blood or plasma from a live animal improves preservation of function of perfused hearts, and cross-circulated plasma performs similarly to cross-circulated whole blood.
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