Patent Publication Number: US-11026668-B1

Title: Amnio opening occlusion device with removal element

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This patent application is a divisional of patent application Ser. No. 17/062,104 filed on Oct. 2, 2020. The subject matter of patent application Ser. No. 17/062,104 is hereby incorporated by reference in its entirety. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable. 
     INCORPORATION BY REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC 
     Not Applicable. 
     TECHNICAL FIELD 
     The disclosed embodiments relate to the field of medical devices and more specifically to medical devices used to close or occlude an opening in a patient. 
     BACKGROUND 
     Fetal surgery is any of a broad range of surgical techniques and processes that are used to treat birth defects or other medical problems in fetuses who are still in the pregnant uterus. Open fetal surgery involves completely opening the uterus to operate on the fetus. Minimally invasive endoscopic fetal surgery (operative fetoscopy) uses small skin incisions and is performed using endoscopy and sonography. Minimally-invasive fetoscopic surgery uses real-time video imagery from fetoscopy and ultrasonography to guide very small surgical instruments into the uterus in order to perform the surgical tasks. Less invasive than open fetal surgery, some fetal surgeries can be achieved with just a small incision on the skin of the mother (percutaneous), though in some cases it may require that a small opening be made in the mother&#39;s abdomen. The fact that it is less invasive reduces the mother&#39;s postoperative recovery and lessens the troubles with preterm labor. Minimally invasive fetoscopic surgery has proven to be very useful for most, but not all, fetal or placental conditions 
     One of the problems associated with even minimally invasive fetoscopic surgery is the opening that is made in the pregnant patient&#39;s uterus in order to operate on the fetus or the placenta. This opening, which results from the insertion of the trocar or other medical instruments, can be the cause of later problems in the patient. Said opening can cause the fetal membrane to separate from the uterine wall, otherwise known as chorioamniotic separation or membrane detachment, which can lead to complications. Chorioamniotic separation may result either in extravasation of the amniotic fluid between the amnion and the chorion, which may hinder further access to the amniotic cavity, or in gross leakage of fluid via the patient&#39;s vagina. In the latter case, the pregnancy is at risk for being lost due to premature rupture of said membranes. Said leakage through the opening and out of the vagina can further result in infection or other difficulties. 
     Therefore, there exists a need for improvements over the prior art, and more particularly for a more efficient way of treating the opening that is made in the pregnant patient&#39;s body during fetoscopic surgery. 
     SUMMARY 
     In one embodiment, a medical device is disclosed. This Summary is provided to introduce a selection of disclosed concepts in a simplified form that are further described below in the Detailed Description including the drawings provided. This Summary is not intended to identify key features or essential features of the claimed subject matter. Nor is this Summary intended to be used to limit the claimed subject matter&#39;s scope. 
     The disclosed collapsible medical device is used for occluding an opening used for fetoscopic surgery. The device comprises tubular woven metal fabric comprised of a plurality of braided metal strands, said woven metal fabric having an expanded preset configuration comprising an hourglass-shaped element and a waist element at a midpoint of the hourglass-shaped element; wherein each end of the hourglass-shaped element has a diameter of about 5 mm; wherein the waist element has a diameter that is less than a diameter of each end of the hourglass-shaped element; said expanded preset configuration of said woven metal fabric further comprising a bulbous element coupled to one end of the hourglass-shaped element via a shaft; wherein the woven metal fabric is deformable to a lesser cross-sectional dimension for delivery through a channel in a patient&#39;s body to said opening used for fetoscopic surgery; and the woven metal fabric having a memory property whereby the medical device returns to said expanded preset configuration when unconstrained. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute part of this specification, illustrate embodiments of the claimed subject matter and together with the description, serve to explain the principles of the claimed embodiments. The embodiments illustrated herein are presently preferred, it being understood, however, that the claimed embodiments are not limited to the precise arrangements and instrumentalities shown, wherein: 
         FIG. 1  is a top perspective view of the collapsible medical device in a fully deployed mode, according to one embodiment. 
         FIG. 2  is a bottom perspective view of the collapsible medical device in a fully deployed mode, according to one embodiment. 
         FIG. 3  is a side view of the collapsible medical device in a fully deployed mode, according to one embodiment. 
         FIG. 4  is a side cross-sectional view of the collapsible medical device in a fully deployed mode, according to one embodiment. 
         FIG. 5  is a top perspective view of a delivery tube including the collapsible medical device in a fully retracted mode, according to one embodiment. 
         FIG. 6  is a top perspective view of the delivery tube including the collapsible medical device in a semi-deployed mode, according to one embodiment. 
         FIG. 7  is a side view of the delivery tube being inserted into a patient&#39;s opening, according to one embodiment. 
         FIG. 8  is a side cross-sectional view of the delivery tube being inserted into a patient&#39;s opening, according to one embodiment. 
         FIG. 9  is a side view of the delivery tube having been inserted into the patient&#39;s opening, wherein the collapsible medical device is in a semi-deployed mode, according to one embodiment. 
         FIG. 10  is a side cross-sectional view of the delivery tube having been inserted into the patient&#39;s opening, wherein the collapsible medical device is in a semi-deployed mode, according to one embodiment. 
         FIG. 11  is a side view of the collapsible medical device in a fully-deployed mode in the patient&#39;s opening, according to one embodiment. 
         FIG. 12  is a side cross-sectional view of the collapsible medical device in a fully-deployed mode in the patient&#39;s opening, according to one embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     The disclosed embodiments improve upon the problems with the prior art by providing a collapsible medical device that is easily deployed for use in occluding an opening used for fetoscopic surgery. The disclosed embodiments improve over the prior art by providing a safe, inexpensive and user-friendly method for occluding an opening used for fetoscopic surgery. Additionally, the disclosed embodiments improve over the prior art by providing a medical device that prevents or reduces the incidence of chorioamniotic separation or membrane detachment, which can otherwise lead to complications. Further, the disclosed embodiments reduce the likelihood of losing a pregnancy due to premature rupture of said membranes, as well as the likelihood of infection and other maternal and fetal difficulties. Also, the disclosed embodiments improve over the prior art by providing a medical device that is easily deployable via a catheter or trocar, thereby reducing the number or size of incisions that must be made in a patient&#39;s body. Additionally, the disclosed embodiments allow for the easy removal of the device from the patient, via a structural removal element, at a later time, such as after the patient gives birth. 
     The claimed embodiments shall now be described with reference to  FIGS. 1-9  where there is shown generally the device  100  suitable for occluding an opening in a patient&#39;s body, such as an opening in a uterus made during fetoscopic surgery. In its relaxed, unstretched state (see  FIGS. 1-4 ), the device generally includes a tubular woven metal fabric comprised of a plurality of braided metal strands ( 111 ,  112 ,  113 ), said woven metal fabric having an expanded preset configuration comprising an hourglass-shaped element  101  having a waist element  105  at a midpoint of the hourglass-shaped element, and a bulbous element  103  coupled to the hourglass-shaped element  101  via a shaft  102 . In one embedment, each end of the hourglass-shaped element (i.e., the thicker portions of the hourglass element at each end) has a diameter of about 8-10 mm. The waist element may have a diameter that is less than a diameter of each end of the hourglass-shaped element. The expanded preset configuration of said woven metal fabric may further comprise a bulbous element  103  coupled to one end of the hourglass-shaped element via a woven shaft  102 . The woven metal fabric is deformable to a lesser cross-sectional dimension for delivery through a channel in a patient&#39;s body to said opening used for fetoscopic surgery. The woven metal fabric may have a memory property whereby the medical device  100  tends to return to said expanded preset configuration when unconstrained. 
     It should be noted that the bulbous element  103  is configured for removal of the device  100  at a time later that its deployment, such as after the patient has given birth. For this reason, the bulbous element  103  may be referred to as a removal element, which refers to the ability to remove the device  100  from the patient by providing an element ( 103 ) that is easily grabbed and may be pulled with enough force to remove device  100  from the patient without causing unnecessary tissue damage to the patient. The shape of bulbous element  103  is configured to allow a surgeon to easily grab the element  103  using a medical instrument, such as obstetrical forceps. The construction of bulbous element  103  is configured to allow the surgeon to pull the element  103  while maintaining the structural integrity of the device  100 , for the purpose of removal of the entire device  100 , all in one piece, from the patient. In one embodiment, when the bulbous element  103  is pulled, the device  100  collapses, as shown in  FIGS. 5 and 8 , for easier and quicker removal from the patient. 
       FIGS. 1-4  shows that the device  100  includes two spaced apart occluding members  104 ,  106  (shaped like truncated cones, for example) interconnected by a flexible, resilient center portion  105  (called a waist). The first cone shaped element  104  (truncated cone) is coupled to the second cone shaped element  106  (also a truncated cone) at the waist  105 . Note that the first cone shaped element  104  is oriented in an inverted manner with respect to the second cone shaped element such that the truncated tip of the first cone shaped element  104  is coupled to the truncated tip of second cone shaped element  106 . Note also that the first cone shaped element  104  and the second cone shaped element  106  are arranged such that the their longitudinal axes are aligned and colinear, wherein the longitudinal axis of a truncated cone is defined as a line that extends from a midpoint of the circular base of the cone to the center of the truncated tip of the cone. 
     The members  104 ,  106  and the waist  105  comprise the hourglass-shaped element  101 . The plurality of braided wires ( 111 ,  112 ,  113 ) form an outer and inner surface of each member  104 ,  106 , the waist  105 , bulbous element  103  and the shaft  102 . The shape of the hourglass-shaped element  101  ensures that the members  104 ,  106  and the waist  105  contact the wall of the opening being occluded. In the preferred embodiment, the occluding device is formed from a single continuous tubular metal fabric. The tubular fabric is formed from a plurality of wire strands having a predetermined relative orientation between the strands. This tubular fabric is known in the fabric industry as a tubular braid. 
     Note that the elements of the device  100 , including the hourglass-shaped element  101 , the bulbous element  103  and the shaft  102 , are all composed of the tubular woven metal fabric comprised of a plurality of braided metal strands ( 111 ,  112 ,  113 ), wherein said woven metal fabric has an expanded preset configuration that includes an inner surface and an outer surface of the device  100 . That is, in the expanded preset configuration, the device  100  comprises a three-dimensional shape with an interior volume that is hollow and a surface that is comprised of the tubular woven metal fabric. 
     The device  100  of the claimed embodiments has a specific shape which is particularly well suited for occluding an opening made in a uterus during fetoscopic surgery. Fetoscopic surgery is a form of fetal intervention in the treatment of birth defects and other fetal problems. The device has a relaxed low-profile configuration and may include one or more clamps (at  130 ,  131 , for example) that allow attachment of the device to an end of a guidewire  730 . The first clamp  130  may be located at a proximal end  150  of the device  100  and the second clamp  131  may be located at a distal end  151  of the device  100 . When the device  100  is in a relaxed state, the occluding members  104 ,  106  expand outwards or perpendicular to the longitudinal axis of the device. In this manner, when the occluding members are pulled apart, the spring-like action of the device will cause the exterior surface of the hourglass-shaped element  101  to fully engage the sidewall of the opening.  FIGS. 8-11  illustrate sequentially the stretching, spring-like action of the device. 
     The disclosed embodiments are formed from a resilient metal fabric a plurality of resilient strands or wires ( 111 ,  112 ,  113 ), with the metal fabric being formed by braiding the resilient strands to create a resilient material. This braided fabric is then deformed to generally conform to a molding surface of a molding element and the braided fabric is heat treated in contact with the surface of the molding element at an elevated temperature. The time and temperature of the heat treatment is selected to substantially set the braided fabric in its deformed state. After the heat treatment, the fabric is removed from contact with the molding element and will substantially retain its shape in the deformed state. The braided fabric so treated defines a relaxed state of the medical device  100  which can be stretched or expanded and deployed through a catheter into a channel in the patient&#39;s body. 
     The claimed embodiments shall now be described with reference to  FIGS. 5-12  where the device  100  is shown in the process of a surgery for occluding an opening in a patient&#39;s body, such as an opening in a uterus made during fetoscopic surgery. In use, a catheter  500  is positioned and advanced in a patient&#39;s body such that the distal end  702  of the catheter is adjacent a desired treatment site for occluding an opening or treating a physiological condition, as shown in  FIG. 7 . The medical device  100  is then stretched and inserted into the lumen of the catheter, as shown in  FIGS. 5 and 8 .  FIGS. 5, 7 and 8  show views of the device  100  in fully retracted mode within the catheter, which is already located at the treatment site. The device  100  is then urged through the catheter by the guidewire  730  and out the distal end, as shown in  FIGS. 6, 9 and 10 , which show the device  100  in a semi-deployed mode exiting the catheter at the treatment site. Subsequently, the device  100  is pushed completely out of the catheter, and, due to its shape memory property, it will tend to substantially return to its relaxed state adjacent the treatment site, as shown in  FIGS. 11 and 12 , which shows the device  100  in a fully deployed state at the treatment site. The guidewire is then released from the clamp(s) and removed. 
     A catheter  500  or other suitable delivery device may be positioned within a channel in a patient&#39;s body to place the distal end  702  of the delivery device adjacent the desired treatment cite, such as immediately adjacent (or even within) the opening  750  in the patient, such as in an organ, as shown in  FIGS. 7-8 . The guide wire  730  can take any suitable shape, but desirably comprises an elongate flexible metal shaft having a threaded distal end. The guide wire can be used to urge the medical device  100  through the lumen of the catheter  500  for deployment in an opening of a patient&#39;s body, as shown in  FIGS. 9 and 10 . When the device is fully deployed out the distal end of the catheter (as shown in  FIGS. 11-12 ), the device will still be retained by the guide wire. Once the medical device is properly positioned within the opening (as shown in  FIGS. 11-12 ), the distal end of the catheter may be pressed against the medical device and the guidewire can be rotated about its axis to unscrew the medical device from the threaded distal end of the guidewire. The catheter and guidewire are then withdrawn. 
     By keeping the medical device  100  attached to the guide wire, the operator can retract the device for repositioning relative to the opening  750 , if it is determined that the device is not properly positioned within the opening. A threaded clamp at  130  attached to the medical device allows the operator to control the manner in which the medical device is deployed out the distal end of the catheter. When the device exits the catheter, it will tend to resiliently return to a preferred relaxed shape, as shown in  FIGS. 11 and 12 . When the device springs back into this shape, it may tend to act against the distal end of the catheter effectively urging itself forward beyond the end of the catheter. This spring action could conceivably result in improper positioning of the device if the location of the device is critical, such as where it is being positioned in an opening. Since the threaded clamp can enable the operator to maintain a hold on the device during deployment, the spring action of the device can be controlled by the operator to ensure proper positioning during deployment. 
     During the initial deployment, the medical device  100  can be collapsed into its collapsed configuration and inserted into the lumen of the catheter  500 , as shown in  FIGS. 5 and 8 . The collapsed configuration of the device may be of any shape suitable for easy passage through the lumen of the catheter and proper deployment out the distal end of the catheter. For example, the device may have a relatively elongated collapsed configuration wherein the device is stretched along its longitudinal axis, which extends through a midline axis of the hourglass shaped element  101 , the shaft  102  and the bulbous element  103 . This collapsed configuration can be achieved simply by stretching the device generally along its longitudinal axis, e.g. by manually grasping the clamps  130 ,  131  and pulling them apart, which will tend to collapse the relaxed diameter portions of the device inwardly toward the device&#39;s longitudinal axis. Loading the device into the catheter may be done at the time of implantation. 
     Upon full deployment, the device  100  is used to occlude an opening in the patient&#39;s body, and once this is accomplished (as shown in  FIGS. 11-12 ), the catheter is removed from the patient&#39;s body. This leaves the medical device deployed in the patient&#39;s opening  750  so that it may occlude the opening in the patient&#39;s body. Before removing the catheter, it may be necessary to detach the medical device from the guidewire before removing the catheter and the guidewire. In one embodiment, the opening  750  may comprise an opening, hole or orifice made during fetoscopic surgery, or the opening may comprise an abnormal opening, hole or orifice that arose out of a medical condition. 
     Those skilled in the art will appreciate that the device is sized in proportion to the opening to be occluded. The diameter of each occluding members  104 ,  106  and waist  105  may be varied as desired for differently sized openings in the uterus. If the size of the opening is 3.8 mm, then the size of the occluding members is 5 mm; if the size of the opening is 5 mm, then the size of the occluding members is 7 mm; if the size of the opening is 7 mm, then the size of the occluding members is 9-10 mm Both occluding members may be the same size. Further, the thickness of the waist may be varied depending upon the thickness of the uterine wall and the fetal membrane, and may range between 0.5 to 1 cm. 
     In one embodiment, the claimed device  100  includes a bulbous element  103 , which is coupled to the hourglass shaped element  101  via a shaft  102 . The purpose of the bulbous element is to provide a structural element, also referred to as a removal element, that can be grabbed and pulled at the time of removal of the device  100  from the patient&#39;s body. In certain fetal surgeries, the device  100  is only meant to reside within the patient for a limited amount of time. For example, in one embodiment, the device  100  is only meant to reside within the patient during pregnancy, after which the device is to be removed. After the device  100  has resided within the patient&#39;s body for a certain period of time, however, the device can become lodged within the patient&#39;s body due to tissue growth, debris or growth due to pregnancy. In this case, the bulbous element  103  provides a structural element, integrated into the tubular woven metal fabric that comprises the hourglass-shaped element  101 , such that the bulbous element can be grabbed and pulled at time of removal of the device  100  from the patient&#39;s body, such that the device  100  may be removed all at once and intact. When placed in the uterus, the device  100  does not promote cell ingrowth and is configured to be removed at the time of delivery of the baby. 
     In one embodiment, the women metal fabric of the claimed device  100  may comprise a shape-memory alloy that can be deformed when cold but returns to its pre-deformed (“remembered”) shape when heated. Said shape-memory alloy may also be called memory metal, memory alloy, smart metal, smart alloy, or muscle wire. In another embodiment, the women metal fabric of the claimed device  100  may comprise a shape-memory polymer, which is a polymeric smart material with the ability to return from a deformed state (temporary shape) to its original (permanent) shape induced by an external stimulus (trigger), such as a temperature change. 
     Although specific embodiments have been disclosed, those having ordinary skill in the art will understand that changes can be made to the specific embodiments without departing from the spirit and scope of the invention. The scope of the invention is not to be restricted, therefore, to the specific embodiments. Furthermore, it is intended that the appended claims cover any and all such applications, modifications, and embodiments within the scope of the invention.