Development of an Artificial Placenta: Survival of Isolated Goat Fetuses for Three Weeks with Umbilical Arteriovenous Extracorporeal Membrane Oxygenation

Unno, Nobuya; Kuwabara, Yoshinori; Okai, Takashi; Kido, Koji; Nakayama, Hirofumi; Kikuchi, Akihiko; Narumiya, Yumiko; Kozuma, Shiro; Taketani, Yuji; Tamura, Masanori

doi:10.1111/j.1525-1594.1993.tb03181.x

Cited by 64 publications

(58 citation statements)

References 10 publications

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“…PO2 values of UA and UV in the goat fetus are known to range from 17.3 to 24 mmHg and from 30 to 33 mmHg, respectively. Fetal baseline data shown in Table 1 are in agreement with those of previous studies (4,9). PCO2 values were higher than normal values probably due to the higher CO2 production in the room air outside the uterus.…”

Section: Discussionsupporting

confidence: 82%

Extrauterine Incubation of Fetal Goats Applying the Extracorporeal Membrane Oxygenation via Umbilical Artery and Vein

Pak¹,

Song²,

So³

et al. 2002

J Korean Med Sci

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The fetus is an unstable subject for an isolated physiological and biochemical study. To study the fetus in a controlled and stable environment, a trial was done using 12 goat fetuses. Extrauterine incubation system was devised using an extracorporeal membrane oxygenation system. The system consisted of a venous reservoir with a servo-controlled roller pump and a membrane oxygenator. The extra-corporeal circuit and membrane oxygenator were primed with the maternal whole blood of 200 mL. Fetal umbilical cords was exposed by Cesarean section. Fetal umbilical arterial blood was drained via the drainage cannula. The drained blood was perfused to the oxygenator by the roller pump. The highly oxygenated and decarboxylated blood was returned to an umbilical vein via the perfusion catheter. The blood flow rate was controlled manually using a roller pump. Fetal heart rate, blood pressure, and electrocardiogram were continuously recorded. Gas analysis of drained and perfused blood was performed hourly. With this system, the fetuses were able to survive under fairly stable physiological condition for periods of up to 34 hr. The extrauterine incubation system used in this study could therefore be a encouraging future experimental model in researching the artificial placenta for premature fetuses.

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Section: Discussionsupporting

confidence: 82%

Extrauterine Incubation of Fetal Goats Applying the Extracorporeal Membrane Oxygenation via Umbilical Artery and Vein

Pak¹,

Song²,

So³

et al. 2002

J Korean Med Sci

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“…The use of an artificial placenta has been proposed, but previous studies have had limited success, possibly because the circuit volume was too large and the resistance of the circuit was too high (1)(2)(3)(4)(5). A more compact circuit may be a solution; in 2009, Reoma et al reported a 4-h survival period using a pumpless artificial placenta for the first time (6).…”

mentioning

confidence: 99%

Novel modification of an artificial placenta: pumpless arteriovenous extracorporeal life support in a premature lamb model

et al. 2012

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Background: Previous studies aimed at developing an artificial placenta have had limited success. We hypothesized that the introduction of a high-performance membranous oxygenator to a pumpless artificial placenta could prolong the survival time of premature lambs. Methods: Immediately after delivery of the fetuses, the umbilical vessels were cannulated and connected to the pumpless artificial placenta. Both the fetuses and the circuit were submerged in a warm saline bath. results: Five fetuses survived for 18.2 ± 3.2 (mean ± seM) h after attachment to the artificial placenta, which maintained fetal circulation. circuit blood flow was positively correlated with mean arterial pressure and negatively correlated with blood lactate levels. Milrinone administration transiently decreased lactate levels, although dopamine administration unexpectedly induced a marked increase in the lactate levels despite an elevated arterial pressure and improved circuit blood flow. conclusIon: We prolonged the survival of fetal lambs using a high-performance membranous oxygenator with a small priming volume. The increased systemic resistance induced by vasoconstrictors may increase the circuit blood flow excessively, resulting in circulation failure in systemic organs; therefore, vasodilators may be more useful than vasoconstrictors for maintaining organ blood flow within this circuit.d espite progress in neonatal intensive care, effective treatments for premature low-birth-weight infants with cardiopulmonary abnormalities are lacking. The use of an artificial placenta has been proposed, but previous studies have had limited success, possibly because the circuit volume was too large and the resistance of the circuit was too high (1-5). A more compact circuit may be a solution; in 2009, Reoma et al. reported a 4-h survival period using a pumpless artificial placenta for the first time (6). However, the fetuses could not survive for longer than 4 h because of fetal circulatory deterioration. The authors concluded that prolonging the survival time any further was difficult without the assistance of a roller pump.Is it impossible to prolong the survival time using a pumpless artificial placenta? The goal of our study was to prolong survival time by improving the following two points. First, we developed a high-performance membranous oxygenator jointly with the group of A. Funakubo, who is a pioneer in the development of the membranous oxygenator (7,8). Our membranous oxygenator enabled a reduction in priming volume of 40%, as compared with that used in Reoma's experiment (6), while maintaining membrane surface area. Second, we administered a vasodilator to the fetuses to maintain circulation in systemic organs. Table 1 compares the values obtained in Reoma's experiments (6) with those obtained in our study. The fetuses in our experimental group had a shorter gestational age, a lower birth weight, and a longer survival time than those in Reoma's experiment. In this study, five fetuses were successfully connected to the artificial placenta,...

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“…The details o f the extrauterine incubation system o f an isolated goat fetus have been reported by Kuwabara and co-workers [10,11], In brief, a cesarean section was performed under general anesthesia with 4% halothane. Fetal hind legs were extracted and the umbilicus was fully exposed.…”

Section: Methodsmentioning

confidence: 99%

Cardiovascular Responses of Goat Fetuses to Hypercapnia during Extrauterine Incubation Using Extracorporeal Membrane Oxygenation

et al. 1997

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The purpose of this study was to assess the effects of changes in fetal PaCO₂ on circulatory functions without maternal influences. In 5 goat fetuses that were incubated using an extrauterine incubation system with arteriovenous extracorporeal membrane oxygenation, fetal carotid arterial blood flow, heart rate, mean blood pressure, and serum catecholamine levels were determined under the conditions of several grades of hypercapnia without hypoxemia. The hypercapnia was induced gradually by decreasing the flow of gas to the membrane oxygenator located on the extracorporeal circulation system. Fetal arterial CO₂ tension increased significantly, from 36.2 ± 1.1 mm Hg (means ± SE) to 82.9 ± 6.5 mm Hg, and the pH decreased significantly, from 7.410 ± 0.012 to 7.121 ± 0.028, due to the hypercapnia. In all cases, the fetal carotid arterial blood flow increased significantly (from 42.2 ± 6.2 to 52.4 ± 6.2 ml/min). Although a slight increase was observed in the heart rate at the mild hypercapnia stage, severe hypercapnia induced bradycardia in all cases. The mean arterial pressure and rate of extracorporeal circulation were unchanged during hypercapnia. We found that cerebral blood flow increased due to hypercapnia’s direct effect on the vascular system, but the response of the peripheral chemoreceptor to hypercapnia seemed to be attenuated in chronic stimulation because bradycardia was induced in chronic hypercapnia.

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Development of an Artificial Placenta: Survival of Isolated Goat Fetuses for Three Weeks with Umbilical Arteriovenous Extracorporeal Membrane Oxygenation

Cited by 64 publications

References 10 publications

Extrauterine Incubation of Fetal Goats Applying the Extracorporeal Membrane Oxygenation via Umbilical Artery and Vein

Extrauterine Incubation of Fetal Goats Applying the Extracorporeal Membrane Oxygenation via Umbilical Artery and Vein

Novel modification of an artificial placenta: pumpless arteriovenous extracorporeal life support in a premature lamb model

Cardiovascular Responses of Goat Fetuses to Hypercapnia during Extrauterine Incubation Using Extracorporeal Membrane Oxygenation

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