Patent Application
20220061831
Multiple surgical situations call for the apposition, approximation, and fixation of two or more layers of tissue without the luxury of direct visualization. Examples include laparoscopic abdominal surgery (e.g., colo-rectal, bariatric, etc.), gastropexy (e.g., attaching the stomach to the abdominal wall), endoscopy (e.g., colonoscopy, GI endoscopy, etc.), cardiothoracic surgery, urogynecologic surgery, and others.
One specific example of these situations occurs when there is a need to approximate the uterine (e.g., the chorioamniotic) membranes to the uterine wall in fetal surgery under ultrasound guidance. Conditions such as spina bifida may be treated through open fetal surgery or performed through ports placed in the uterus, which may be generally referred to as fetoscopic surgery. Numerous other congenital fetal abnormalities exist that may benefit from fetoscopic surgery, such as congenital diaphragmatic hernia (CDH), critical aortic valve stenosis, twin-twin transfusion syndrome (TTTS), fetal lower urinary tract obstruction etc.
In order to perform fetoscopic surgeries, a trocar or port is often implanted through the abdomen, through the wall of the uterus, and through the placental membrane. However, these insertions may cause defects in the uterine membranes and may lead to separation of the chorion and the amnion or rupturing of the placental membranes (e.g., preterm premature rupture of membranes), which may in turn lead to premature delivery of the baby.
To reduce the risk of premature rupture of membranes, the conventional approach in fetal surgery is to place sutures to “anchor” the placental membrane to the uterine wall. However, this requires an incision in the maternal abdomen (e.g., a laparotomy) to exteriorize the uterus. Thus, anchoring the chorioamniotic membranes in some cases cannot be accomplished when the fetal surgery is performed using a percutaneous approach (e.g., without laparotomy and uterine exteriorization). In addition, when the uterus is exteriorized, the sutures are placed under ultrasound guidance using curved needles; however, the ultrasonographic visualization of a curved needle to place a suture in the uterus is frequently challenging. The conventional approaches for some fetal surgeries are highly invasive surgery because they require laparotomy and manipulation of the uterus, which typically requires longer recovery time post-surgery.
One aspect of the invention provides a fastener assembly for securing a first bodily wall to a second bodily wall. The fastener assembly includes: a first cylindrical fastener defining a first set of cross lumens, each of the first set of cross lumens extending substantially perpendicular to a central axis of the first cylindrical fastener; a second cylindrical fastener defining a second set of cross lumens, each of the second set of cross lumens extending substantially perpendicular to a central axis of the second cylindrical fastener; and a string running through the first set of cross lumens of the first cylindrical fastener and the second set of cross lumens of the second cylindrical fastener, such that the tightening of the string will draw the first cylindrical fastener and the second cylindrical fastener towards each other.
This aspect of the invention can have a variety of embodiments. The string can be fastened to itself with a locking-sliding knot. The string can be fastened to itself with a Weston knot or a Meltzer knot.
The first cylindrical fastener and the second cylindrical fastener can each have a maximum cross-sectional dimension of about 2.5 mm.
The first cylindrical fastener, second cylindrical fastener, and the string can comprise a resorbable polymer composition. The resorbable polymer composition can comprise one or more materials selected from the group consisting of: polyglycolide-lactide copolymers, polyglactin 910, polydioxanone (PDS), polyglycolic acid, polylactic acid, polycaprolactone, and polylactide-caprolacrone copolymers. The first cylindrical fastener, the second cylindrical fastener, the string, of a combination thereof, can comprise one or more materials selected from the group of: thermoplastic bioresorbable polyurethanes with degradable hard and soft segments, synthesized from polyester polyols, and aromatic or aliphatic isocyanates. The design of the cylindrical fastener and string, and the polymer composition can be engineered to provide a target degradation time.
The first cylindrical fastener can further define a recess located along a longitudinal axis of the first cylindrical fastener. A portion of the string can rest in the recess when the longitudinal axis of the first cylindrical fastener is perpendicular to the first bodily wall, the second bodily wall, or both. The longitudinal axis of the first cylindrical fastener can reposition from being substantially perpendicular to the first bodily wall, the second bodily wall, or both, to being substantially parallel to the first bodily wall, the second bodily wall, or both, during the tightening of the string.
Another aspect of the invention provides an anchor delivery or deployment device including: a shaft defining a longitudinal cavity, the longitudinal cavity having a set of dimensions to fit the fastener assembly as described herein within the longitudinal cavity.
This aspect of the invention can have a variety of embodiments. The anchor delivery or deployment device can further include an obturator having a piercing end, the obturator having a width to allow the obturator to fit within the longitudinal cavity of the shaft. The obturator can terminate in a handle opposite the piercing end. The shaft can further include a cannula.
Another aspect of the invention provides a method of securing a first bodily wall to a second bodily wall of a subject. The method includes: inserting the shaft of the anchor device as described herein into the skin of the subject, through the first bodily wall and through the second bodily wall; inserting the fastener assembly into the shaft of the anchor device; deploying the first cylindrical fastener inside of the second bodily wall; withdrawing the shaft of the anchoring device through the second bodily wall and the first bodily wall; deploying the second cylindrical fastener from the shaft of the anchoring device and outside of the first bodily wall; cinching the first cylindrical fastener and the second cylindrical fastener together by pulling one or both ends of the string; and withdrawing the shaft of the anchoring device completely from the skin of the subject.
This aspect of the invention can have a variety of embodiments. The method can further include inserting an obturator into the skin of the subject to define an opening through the first bodily wall and the second bodily wall, wherein inserting the shaft of the anchor device further comprises inserting the shaft of the anchor device into the opening. Insertion and manipulation of the obturator can be aided by medical imaging. The medical imaging can be ultrasound or direct visualization using a laparoscope or fetoscope.
The first bodily wall can be a uterine wall and the second bodily wall can be a placental membrane. The subject can be a mammal. The subject can be a human. The subject can be a pregnant female.
Another aspect of the invention provides a kit including: a fastener assembly; and instructions to perform a method described herein.
Another aspect of the invention provides a fastener assembly for securing a first bodily wall to a second bodily wall. The fastener assembly includes: a first cylindrical fastener; a second cylindrical fastener; and a string. The first cylindrical fastener defines: a first axial external channel; a second axial external channel; a first cross lumen extending between the first axial external channel and the second axial external channel; and a second cross lumen extending between the first axial external channel and the second axial external channel. The second cylindrical fastener defines: a third axial external channel; a fourth axial external channel; a third cross lumen extending between the third axial external channel and the fourth axial external channel; and a fourth cross lumen extending between the third axial external channel and the fourth axial external channel. The string runs through the first cross lumen and the second cross lumen of the first cylindrical fastener, and the third cross lumen and the fourth cross lumen of the second cylindrical fastener, such that the tightening of the string will draw the first cylindrical fastener and the second cylindrical fastener towards each other.
Another aspect of the invention provides a fastener system comprising: a delivery cylinder comprising: a proximal end adapted and configured for manipulation by a user; and a distal end adapted and configured for advancement through one or more bodily walls; a fastener assembly as described herein; and a pusher. The pusher includes: a proximal end adapted and configured for manipulation by a user; and a distal end adapted and configured for advancement into the delivery chamber, thereby advancing the fastener assembly. The proximal end of the delivery cylinder and the proximal end of the pusher have complimentary mechanical logic that: limits initial advancement of the pusher rod to initially advance only a distal fastener beyond the distal end of the delivery cylinder; and permits further advancement of the pusher in response to a second action to advance a proximal beyond the distal end of the delivery cylinder.
This aspect of the invention can have a variety of embodiments. The pusher can define an axial channel extending between the proximal end and the distal end, the axial channel adapted and configured to receive the string. The axial channel can be internal or external to the pusher.
The complimentary mechanical logic can include a complimentary tab and slot that mate only when the pusher and the delivery cylinder are at certain angles relative to each other.
For a fuller understanding of the nature and desired objects of the present invention, reference is made to the following detailed description taken in conjunction with the accompanying drawing figures wherein like reference characters denote corresponding parts throughout the several views.
The instant invention is most clearly understood with reference to the following definitions.
As used herein, the singular form “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise.
Unless specifically stated or obvious from context, as used herein, the term “about” is understood as within a range of normal tolerance in the art, for example within 2 standard deviations of the mean. “About” can be understood as within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the stated value. Unless otherwise clear from context, all numerical values provided herein are modified by the term about.
As used in the specification and claims, the terms “comprises,” “comprising,” “containing,” “having,” and the like can have the meaning ascribed to them in U.S. patent law and can mean “includes,” “including,” and the like.
Unless specifically stated or obvious from context, the term “or,” as used herein, is understood to be inclusive.
Ranges provided herein are understood to be shorthand for all of the values within the range. For example, a range of 1 to 50 is understood to include any number, combination of numbers, or sub-range from the group consisting 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50 (as well as fractions thereof unless the context clearly dictates otherwise).
In certain aspects, the invention provides a novel fastener assembly for securing a first bodily wall to a second bodily wall. In other aspects, the invention provides for an anchoring device which inserts the fastener assembly inside the body of a subject. In yet other aspects, the invention provides a method of securing a first bodily wall to a second bodily wall using the fastener assembly and implements of the invention.
Sutures or fasteners are used during medical procedures to anchor one bodily wall to another bodily wall. Conventional suture or fastener insertion techniques result in large incisions and invasive procedures, thereby requiring long recovery periods and increased risk for resulting complications (e.g., secondary infections, etc.). Additionally, after such procedures, sutures are known to cause morbidity (e.g., ischemia) of the surrounding tissue and often cause pain and discomfort for the subject. Fasteners established in the art also cause discomfort due to their rigidity and the fact that they are often secured within one of the bodily walls.
Referring to
The fastener 201 may also include a set of slots 210 that run along the longitudinal axis of the fastener 201. The sutures 103 may lie in the slots 210 when the fastener assembly resides in the delivery tube (e.g., fastener 201 is in a perpendicular position relative to a bodily wall). Constraining the suture 103 to follow a single path may prevent unwanted migration of the suture 103 between the fastener 201 and the walls of the delivery tube, which may result in high resistance to the movement of the fastener assembly in the delivery tube and possible jamming.
Fastener 201 may additionally or alternatively include filleted ends 215 to provide for atraumatic surfaces when the fastener 201 is present in a body (e.g., a subject). The radius of the filleted portion may be designed to remove traumatic edges from the fastener 201 (e.g., on the scale of 100 microns).
As described herein, a cylinder is defined as a surface consisting of each of the straight lines that are parallel, or substantially parallel, to a given straight line and pass through a given curve. Further, the dimensions of the cylindrical fastener and corresponding lumens may be designed based on the desired results of the pending surgery. For example, when conducting a procedure on a human subject, the cylindrical fastener may be designed with a smaller diameter as opposed to a fastener intended to be used for a procedure conducted on a horse. Furthermore, different shapes of the fastener (e.g., disk, sphere, rectangular prism, triangular prism, etc.) may be used based on the type of procedure used as well as the intended subject. In addition, the fastener may change shape following deployment from the delivery device (e.g. foldable disk, foldable rectangle, etc.).
In some cases, a custom shape may be designed (e.g., via a 3-D printer or the like) for a subject-specific cylindrical fastener. As such, the distance and location of the lumens may be determined based on the selected shape, dimensions, and desired results. In an exemplary embodiment, the distance between the lumens (e.g., measured from closest-edge-to-closest-edge) of a fastener is approximately 2 mm.
In some cases, the fasteners and sutures are composed of resorbable material, which may biodegrade over a period of time. This may be beneficial in cases where the fasteners are to be used for temporary positioning. The fasteners, suture, or a combination thereof, may be composed of any biodegradable or resorbable polymer, including but not limited to: polyglycolide-lactide copolymers (e.g. polyglactin 910), polydioxanone (PDS), polyglycolic acid, polylactic acid, polycaprolactone, polylactide-caprolactone copolymers, thermoplastic bioresorbable polyurethanes with degradable hard and soft segments, synthesized from polyester polyols, and aromatic or aliphatic isocyanates.
In some of these cases where resorbable material is relied on, the composition may be selected based on a predetermined degradation time, where the structure of the fastener and/or suture fails after the predetermined degradation time (e.g., on the scale of 1 to 36 months). Alternatively, the composition for the fasteners and/or suture may be selected for its ability to maintain its structure for an extended period of time. For example, in cases where a ligament is to be approximated, a composition that maintains it structural integrity permanently may be selected.
The terms “string” and “suture” are used interchangeably herein. Either can be natural, synthetic, hypoallergenic, biocompatible, and/or absorbable. Exemplary materials include absorbables (e.g., polylactic acid, MONOCRYL® sutures available from Johnson & Johnson Corporation of New Brunswick, N.J., poly (4-hydroxybutyric acid) (P4HB available under the MONOMAX® trademark from Aesculap AG of Tuttlingen, Germany)), as well as non-absorbables (e.g., nylon, polyester, PVDF, and polypropylene).
The bodily walls that are to be approximated by the fastener assembly is not to be limited to soft tissue of a subject. For example, some cases may include different type of material to be approximated, including but not limited to ligaments, bone, cartilage, organs, soft tissue, skin, connective tissue, and cavities surrounding different tissues.
A delivery device may include concentric tubes that contain the fastener assembly. The delivery device may push the fastener assembly and advance the locking-sliding knot. An example of a delivery device 500 is illustrated in
The delivery tube 505 may have an inner diameter that matches, or approximately matches, the diameter of the fasteners. The delivery tube 505 may be long enough to penetrate to the space within the innermost layer to be approximated. The delivery tube 505 may include a low wall thickness to keep the outer diameter low, which may minimize tissue damage. The long, straight tube of the delivery tube 505 may aid in visualization under medical imaging, such as ultrasound imaging. An example of a delivery tube is illustrated in
Referring to
An alternative embodiment may include a delivery tube with a sharp tip. The sharp tip may be akin to that of a hypodermic needle. The first fastener, in this embodiment, may be used to occlude the lumen of the delivery tube to avoid coring out tissue during piercing. This embodiment may decrease travel distance for a pusher tube due to the fasteners being already present at the tip of the delivery tube at the initiation of actuation. Additionally, due to the shorter distance, the delivery tube may include alternate gripping methods, such as a hammer grip, with a thumb used to actuate the delivery tube. An example of this alternative embodiment is found in
The delivery tube 505 may be permanently attached to the mating housing 510, which may include holes that bring the delivery tube 505 and the anchor tube 515 together concentrically when the anchor tube 515 is inserted. The mating housing 510 may also include a feature to hold the anchor tube 515 in place after mating (e.g., set screw, thumb screw, magnets, etc.). The opening of the mating housing 510 where the anchor tube 515 is inserted may include a bevel that may guide the anchor tube 515 into the hole. In some cases, the mating housing 510 is also permanently attached to the anchor tube 515, thereby permanently connecting the anchor tube 515 with the delivery tube 505.
The anchor tube assembly may include an inner diameter that may match the diameter of the fasteners and may be long enough to contain the fastener assembly with the suture loop fully stretched out. The tip of the anchor tube 515 may include a bevel that may guide the fasteners into the anchor tube 515 during loading. The anchor tube 515 may be permanently attached to an anchor tube handle. The handle may include a hole that matches a peg on a pusher tube handle, such as pusher tube 520. The hole combined with the peg on the pusher tube handle may provide a mechanical logic that ejects the fasteners individually at the correct locations. The handle of the anchor tube 515 may allow the operator to grip the handle below a disc between two fingers and apply downward forces on the pusher tube handle. An example of an anchor tube assembly is illustrated in
The pusher tube 520 may include an outer diameter that allows for slight clearance with the inner diameter of the anchor tube 515 and delivery tube 505. The clearance may allow for smooth motion but may be kept to a minimum to prevent the migration of the suture to any excess clearance space during ejection, which may result in increased resistance to motion and possible jamming. The tip of the pusher tube 520 may include an opening large enough to allow suture of a given size to pass freely through the opening. When the suture is pulled, the suture may pass through the pusher tube 520 freely but the knot may not advance through the opening. This may advance the knot down the suture, thereby tightening the fastener assembly. The opening at the tip may include a bevel, which may simplify feeding the suture during loading.
Additionally, the pusher tube 520 may be attached to a pusher tube handle. The pusher tube handle may include a peg that matches the hole of the anchor tube handle. The length of the peg may be greater than the length of a fastener. Furthermore, the length of the pusher 520 may be designed such that during operation, when the bottom of the peg contacts the top surface of the anchor tube handle, the first fastener is fully ejected and the second fastener begins its exit from the delivery tube 505. This may ensure that the fasteners are fully ejected at the desired locations. An example of a peg-and-hole mechanism is illustrated in
Additionally, the top of the pusher tube handle may be flat, which may provide sufficient room for the operator to push on the pusher tube handle with a thumb or a second hand. An example embodiment of the pusher tube assembly is illustrated in
The obturator 525 may have a diameter that matches the inner diameter of the delivery tube 505, which may minimize a gap between the obturator 525 and the delivery tube 505. This may allow for a smooth surface transition from the obturator 525 to the delivery tube 505 as the fastener assembly slides through tissue. Additionally, the obturator, such as obturator 1100 in
Some embodiments may allow for a camera or endoscope to be implemented in conjunction with the delivery system. For example, a digital camera may be placed at the tip of the instrument. Additionally or alternatively, there may be a channel inside of the instrument that may allow passage of an endoscope (e.g., a 1 mm endoscope) either to the end of the device tip or past the device tip. The camera or endoscope may allow for an expanded field of view (e.g., 30 or 40 degrees) beyond the tip of the device. In addition, a camera may also be inserted through a previously placed port (e.g., a plastic port), such as ports used in fetal surgery procedures to confirm the proper placement of the anchoring device. Alternatively, the device may be inserted using a sharp trocar placed down the barrel of the device and removed once the device is in position.
Another example of the insertion process is illustrated in
Many fetal surgeries that are performed percutaneously utilize a vascular access port (e.g., 9-12 Fr vascular access port), which may be placed into a uterus under ultrasound guidance through which an endoscope is placed. In order to anchor the chorioamniotic membranes prior to vascular port placement, two fastener assemblies may be deployed under ultrasound guidance inside the uterus and the chorioamniotic membranes. While holding these two fastener assemblies with the delivery tubes, the vascular port may be placed in between the delivery tubes under ultrasound guidance through which the surgical operative procedure will be performed. Once the surgical procedure is completed, the operative fetoscope may then be withdrawn, leaving the barrel of each delivery tube partially embedded within the uterine wall with the first fasteners deployed inside the amniotic cavity.
The abdominal wall may then be elevated with towel clamps such that the abdominal wall is pulled upward toward the ceiling, which may provide a space between the uterus and inside of the abdominal wall. The vascular port may be withdrawn into this space through which a scope may be placed. The second fasteners may then be deployed and tightened under direct visualization to secure the membranes against the outside of the uterine surface using a sliding knot. Direct visualization with the scope may also assist in preventing uterine blanching from occurring, which may suggest that the knot is too tight. The suture may then be cut under vision (e.g., via scissors, etc.) placed down the vascular port. The delivery tubes may then be removed from the subject. The suture tails of the two anchoring devices may be used to close the hole made by the vascular port following fetal surgery using sliding knots, as shown in
Some fetal surgeries may require the fixation of the membranes prior to placing an access port. In this circumstance, the delivery tube with a camera or endoscope (e.g., a STORZ™ 1 mm endoscope) may be used as a standalone instrument. Initial access to the abdominal cavity may be provided using a standard laparoscopic entry (e.g., a 5 mm) port. Once the abdomen is entered, gas (e.g., CO2) may be introduced to create space between the uterus and the abdominal wall. Alternatively, graspers may be used to tent the abdomen.
A sharp-tipped (e.g., diamond-tipped) trocar may be placed down the barrel of the delivery tube. The anchor delivery device may then be pushed through the abdominal wall via the entry port. Once inside the abdomen, the anchor delivery device may be pushed through the uterine wall under vision or ultrasound to enter the amniotic cavity. The trocar may then be removed and the anchor system may be loaded into the barrel of the delivery tube.
The first fastener may be deployed under vision inside the uterus and inside the membranes. The delivery tube barrel may be removed from the inside the uterus back into the abdominal cavity, thereby leaving the first fastener in the amniotic cavity. The second fastener may then be deployed and tightened under vision. Afterwards, the suture may be cut and removed from the delivery tube.
The delivery tube may then be reloaded with the trocar and the same process may be repeated to enter the uterus in a different location. The trocar may be removed once the delivery tube is in the amniotic fluid and the set of fasteners may be loaded and deployed as discussed above. This process may be repeated as necessary to place the desired or required number of fasteners inside the uterus. Once sufficient fasteners are placed, the barrel may then be withdrawn through the entry port. The suture tails of the two anchoring devices may be used to close the hole made by the trocar following fetal surgery using sliding knots, as shown in
To compare the device to the current surgical standard, pull-out tests were performed on a test bed designed for testing these devices. As shown in
Thus, the fastening system displays holding strength comparable to the currently used stitching method while also allowing surgery to be performed fetoscopically.
To test acute handling characteristics of the device and the feasibility of full percutaneous delivery, deployment was tested in a porcine cadaver model (e.g., shown in
To measure the host response to the device while it is implanted, fasteners were implanted in the uteri of pregnant rabbits in their third trimester. Host response was examined through histology of sections of the uterus at the implant site, as shown in
Referring now to
Although preferred embodiments of the invention have been described using specific terms, such description is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims.
The entire contents of all patents, published patent applications, and other references cited herein are hereby expressly incorporated herein in their entireties by reference.
This application claims the benefit of priority to U.S. Provisional Patent Application Ser. No. 62/788,664, filed Jan. 4, 2019. The entire content of this application is hereby incorporated by reference herein.
This invention was made with government support under Grant No. SBIR Phase 1 R43 HD094456-01 awarded by the National Institutes of Health. The government has certain rights in the invention.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2020/012129 | 1/3/2020 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62788664 | Jan 2019 | US |
