CA-2989857-C - METHOD AND APPARATUS FOR EXTRACORPOREAL SUPPORT OF PREMATURE FETUS

Abstract

A system configured to support growth and development of a premature fetus is disclosed. Specifically, a method and apparatus configured to provide extracorporeal support for premature fetuses is disclosed.

Inventors

• Alan Flake
• Marcus Davey

Assignees

• THE CHILDREN'S HOSPITAL OF PHILADELPHIA

Dates

Publication Date

20260505

Application Date

20160617

Priority Date

20150619

Claims (20)

1. What is Claimed: 1. A fetal chamber configured for use in a system configured to enclose a human fetus and maintain the fetus during maturation, the fetal chamber comprising: a rigid frame; at least one flexible wall coupled to the rigid frame, such that the rigid frame and the at least one flexible wall define an interior space, the interior space configured to hold a volume of synthetic amniotic liquid sufficient to immerse the human fetus in the synthetic amniotic liquid; and a turbidity sensor associated with the fetal chamber to monitor the synthetic amniotic liquid within the interior space for the presence of stool from the human premature fetus wherein the presence of stool in the synthetic amniotic liquid thereby creates a contaminated synthetic amniotic liquid within the interior space, wherein 1) the fetal chamber defines a closed configuration in which the interior space defines a volume that is variable, the at least one flexible wall is configured to expand thereby increasing the volume, and the at least one flexible wall is configured to contract thereby decreasing the volume, 2) the fetal chamber further defines an open configuration in which the fetal chamber defines an opening that is configured to accommodate entry of the human fetus into the interior space, and 3) the opening is configured to be closed such that liquid in the interior space is prevented from passing through the opening when the fetal chamber is in the closed configuration.
2. 2. The fetal chamber of claim 1, wherein the rigid frame includes a first portion and a second portion, the first portion coupled to the second portion such that 1) in the open configuration the first portion is movable relative to the second portion, and 2) in the closed configuration the first portion is fixed relative to the second portion.
3. 3. The fetal chamber of claim 2, further comprising a hinge that couples the first portion to the second portion such that in the open configuration the first portion is rotatable away from the second portion to define the opening.
4. 4. The fetal chamber of any one of claims 2 and 3, further comprising a locking mechanism configured to fix the first portion relative to the second portion when the fetal chamber is in the closed configuration.
5. 5. The fetal chamber of any one of claims 1 to 4, further comprising a first end and a second end opposite the first end along a first direction, such that the fetal chamber is elongate along the first direction.
6. 6. The fetal chamber of claim 5, wherein the opening is a first opening, the fetal chamber defines a second opening and a third opening opposite the second opening with respect to the first direction.
7. 7. The fetal chamber of claim 6, wherein the first end defines the second opening and the second end defines the third opening.
8. 8. The fetal chamber of any one of claims 6 and 7, wherein the second opening is configured to provide entry for a fluid into the interior space when the fetal chamber is in the closed configuration, and the third opening is configured to provide exit from the interior space for a fluid when the fetal chamber is in the closed configuration.
9. 9. The fetal chamber of any one of claims 6 to 8, wherein the fetal chamber defines a fourth opening configured to provide entry for a fluid into the interior space when the fetal chamber is in the closed configuration, and wherein a distance between the fourth opening and the first end with respect to the first direction is less than a distance between the second end and the first end with respect to the first direction, and wherein a distance between the fourth opening and the second end with respect to the first direction is less than a distance between the first end and the second end with respect to the first direction.
10. 10. The fetal chamber of any one of claims 1 to 9, further comprising a mechanism configured to support the rigid frame such that the rigid frame is rotatable about an axis of rotation.
11. 11. The fetal chamber of any one of claims 1 to 10, wherein the interior space defines a maximum volume, the fetal chamber further comprising a restrictor configured to be secured to the rigid frame such that the restrictor limits expansion of the interior space and thereby decreases the maximum volume.
12. 12. The fetal chamber of claim 11, wherein the restrictor is configured to be removed from the rigid frame while the fetal chamber is in the closed configuration.
13. 13. A system configured to enclose a human fetus and maintain the fetus during maturation, the system comprising: a fetal chamber including a rigid frame and at least one wall that cooperate to at least partially define an interior space, the interior space defining a volume, the fetal chamber configured such that the volume is variable, wherein the fetal chamber includes an opening that is sized to accommodate entry of a human fetus into the interior space, the opening configured to be closed such that liquid in the interior space is prevented from passing through the opening; a first fluid circuit configured to provide a first fluid to the interior space, the first fluid circuit defining a first path that includes an entry into the fetal chamber and an exit from the fetal chamber; a second fluid circuit configured to provide a second fluid to the interior space such that the second fluid remains separate from the first fluid, the second fluid circuit defining a second path that includes an entry into the fetal chamber and an exit from the fetal chamber.
14. 14. The system of claim 13, wherein the fetal chamber includes an open configuration in which the opening is configured to accommodate entry of a human fetus into the interior space, and the fetal chamber includes a closed configuration in which liquid in the interior space is prevented from passing through the opening.
15. 15. The system of any one of claims 13 and 14, wherein the at least one wall is flexible.
16. 16. The system of any one of claims 13 to 15, further comprising a cart including wheels such that the cart is configured to be transported from one location to another, the cart including a housing that encloses the fetal chamber.
17. 17. The system of any one of claims 13 to 16, wherein the first fluid circuit includes a first supply source of the first fluid, a second supply source of the first fluid, and a mechanism configured to switch the first path to include either the first supply source or the second supply source, the first supply source enclosing a smaller volume of the first fluid than the second supply source.
18. 18. The system of claim 17, wherein the mechanism is a first mechanism, the second fluid circuit includes a first supply source of the second fluid, a second supply source of the second fluid, and a second mechanism configured to switch the second path to include either the first supply source of the second fluid or the second supply source of the second fluid, the first supply source of the second fluid enclosing a smaller volume of the second fluid than the second supply source of the second fluid.
19. 19. The system of any one of claims 13 to 18, wherein the first fluid circuit includes a turbidity sensor configured to detect turbidity of the first fluid in the interior space, the first fluid circuit configured such that a flow rate of the first fluid to and from the interior space is variable in response to turbidity sensed by the turbidity sensor.
20. 20. The system of any one of claims 13 to 19, wherein the first fluid circuit includes a pressure sensor configured to detect pressure of the first fluid in the interior space, the first fluid circuit configured such that a flow rate of the first fluid to and from the interior space is variable in response to pressure sensed by the pressure sensor.

Description

METHOD AND APPARATUS FOR EXTRACORPOREAL SUPPORT OF PREMATURE FETUS TECHNICAL FIELD [0002] The present disclosure relates generally to neonatal care. More specifically, the present disclosure describes devices, systems, and methods related to the maintenance of homeostasis in an extreme premature fetus outside of the womb. According to one aspect, the present disclosure relates to improving outcomes of premature fetuses born prior to 28 weeks gestation. BACKGROUND [0003] Extreme prematurity is the leading cause of infant morbidity and mortality in the United States, with over one third of all infant deaths and one half of cerebral palsy diagnoses attributed to prematurity. Respiratory failure represents the most common and challenging problem associated with extreme prematurity, as gas exchange in critically preterm neonates is impaired by structural and functional immaturity of the lungs. Advances in neonatal intensive care have achieved improved survival and pushed the limits of viability ofpreterm neonates to 22 to 2-1 weeks gestation, which marks the transition from the canalicular to the saccular phase of lung development. Although survival has become possible, there is still a high rate of chronic lung disease and other complications of organ immaturity, particularly in fetuses born prior to 28 weeks gestation. The development of a system that could support normal fetal growth and organ maturation for even a few weeks could significantly reduce the morbidity and mortality of extreme prematurity, and improve quality of life in survivors. [0004] Premature birth may occur due to any one of a multitude of reasons. For example, premature birth may occur spontaneously due to preterm rupture of the membranes (PROM), structural uterine features such as shortened cervix, secondary to traumatic or infectious stimuli, or due to multiple gestation. Preterm labor and delivery is also frequently - I - Date Rer;ue/Date Received 2022-12-08 WO 2016/205622 PCT /0S2016/038045 encountered in the context of fetoscopy or fetal surgery, where instrumentation of the uterus often stimulates uncontrolled labor despite maximal tocolytic therapy. [0005] The 2010 CDC National Vital Statistics Report notes birth rates at a gestational age of less than 28 weeks in the United States over the past decade have remained stable at approximately 0.7%, or 30,000 births annually. Similarly, birth rates at gestational ages 28-32 weeks over the past decade in the United States have been stable at 1.2%, or 50,000 births annually. Patients with pulmonary hypoplasia secondary to congenital diaphragmatic hernia, oligohydramnios, or abdominal wall defects are also significant. The National Birth Defects Prevention Network reports an annual incidence of congenital diaphragmatic hernia between 0.9 to 5.8 per 10,000 live births in the United States, or approximately 375-2,500 births annually. The incidence of other causes of pulmonary hypoplasia is not well documented. [0006] Respiratory failure remains the major challenge to survival in the critically premature infant. The development of an extrauterine system to support ongoing fetal growth and development would represent a changing paradigm in the management of such patients. The development of an "artificial placenta" has been the subject of investigation for over 50 years with little success. Previous attempts to achieve adequate oxygenation of the fetus in animal models have employed traditional extracorporeal membrane oxygenation (ECMO) with pump support, and have been limited by circulatory overload and cardiac failure in treated animals. The known systems have suffered from unacceptable complications, including: I) progressive circulatory failure due to after-load or pre-load imbalance imposed on the fetal heart by oxygenator resistance or by circuits incorporating various pumps; and 2) contamination and fetal sepsis. [0007] Accordingly, despite previous attempts to address the long-felt need for a system to support fetal growth and development for preterm fetuses, a solution has remained elusive. SUMMARY [0008] The present disclosure provides an extracorporeal system to support a mammal, such as a premature fetus. According to one aspect of the disclosure, the system includes a fluid reservoir having one or more flexible walls. The fluid reservoir is configured to enclose a fetus within a fluid environment and may have an expandable volume and a sealable opening. The system may include a fluid supply line configured to supply a volume of fluid into the fluid reservoir. The system may further include a fluid discharge line configured to discharge fluid from the fluid reservoir. The system may include a pumpless pediatric oxygenator configured to WO 2016/205622 PCT /0S2016/038045 exchange oxygen and carbon dioxide in the blood of the fetus while the fetus is maintained within the fluid reservoir. [0009] According to another aspect of the disclosure, a method of treatment for a premature fetus