Vascular occlusion device configured for infants

A microcatheter deliverable implant is provided formed of an elongated wire of a diameter capable of delivery through the axial passage of such a microcatheter. A first portion of the formed implant forms a coiled first section larger in diameter than an anomaly to be blocked. A second portion formed by the coiled wire engages the implant between the first and second portions to block communication of fluid through the anomaly.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to vascular occlusion devices employed for occluding vascular structures. More particularly the disclosed device and method relate to an occlusion device which is configured for implantation through the extremely narrow and serpentine vascular structures of newborns and infants where heretofore such devices were not employable. Further, the device provides a novel deployed implant especially configured to maintain a secure mount at the implant site which in infants and newborns is especially challenging due to the small nature of such sites and the thin and delicate surrounding tissue.

2. Prior Art

There are many instances in medicine where patients may have blood vessels and other unwanted vascular structures (sometimes man made structures) which need to be blocked or segregated from fluid passages of the vascular system, in order to treat the patient. Such devices may include stents or in a majority of cases where an occlusion of the site is desired, shaped metal coils are employed which, once released, provide a means for blocking an intended vascular passage.

Such metal coil implants are initially engaged in a catheter or delivery tube in a linear fashion and an elongated shape or configuration, in order for the shaped metal implant to follow the axial conduit within the catheter for implantation from the distal end of the catheter at the delivery site. Formed of coiled memory metal, the coils of the implant, upon deployment from the distal end of the catheter, wind to their original shape to form a blocking component configured to block or segregate a section of the vascular system desired from the adjacent system.

However, because such coil devices are delivered to a deployment site within these vascular structures with catheters, when the patient is an infant or newborn child, a severe problem arises. This is because when these vascular structures exist in very small children and infants, as well as in difficult to access parts of the body (as is the case for the brain, coronary arteries or other tortuous vessels in the abdomen), it becomes necessary that the coil-shaped implant be delivered by translation through the conduit of very small tubes called microcatheters.

However, because the physical requirements of the cross section of the axial conduit of such small microcatheters, conventionally sized and tensioned coil-shaped occlusion devices do not work well. Most implants have cross sections of the coil of the implant, which even in an elongated positioning of the wire forming the coil, exceed the diameter of microcatheter devices. Those that have a sufficiently narrow coil diameter to translate through the conduit of a microcatheter when deployed have not worked well in infants and children because they lack the tension on deployment for a secure engagement to the vascular or surrounding tissue. Such conventional devices of lower tension, in addition, have shapes which on deployment lack the ability to achieve a secure compressive engagement to occlude apertures in infants, such as between heart chambers, and remain engaged to the tissue surrounding the aperture being sealed.

Employment of such conventional coils can result in a dismounted coil for instance when deployed to seal a patent ductus arteriosus (PDA) in an infant or newborn who have high heart rates of 150 beats or more. In addition to the movement imparted by the heart beats, such infants have thin delicate tissue which must provide the engagement for the deployed implant. Such a dismount should it occur, is life threatening and requires immediate more invasive surgery to remove the dismounted implant which is additionally life threatening.

As such, there is a continuing unmet need for catheter-delivered implant capable of translation and delivery through a microcatheter which is required in the treatment of infants and newborns and in very small vascular system areas in adults. Additionally, such a device, on deployment, must achieve the desired occlusion and concurrently a secure engagement to the tissue of the patient, in high blood flow areas which impart extra force against the implant which can lead to dislodgement.

The present invention solves the shortcomings of the current art, in providing a vascular occlusion coil-type implant which can be delivered via translation through a microcatheter for implantation in infants and newborns and small blood vessels. The disclosed device in such a communication through the axial passage of a microcatheter, once deployed and engaged with patient tissue, provides the desired occlusion for very high flow vascular structures. The disclosed device accomplishes these tasks, using a coil which is coiled to extremely high tension resistance to coil-elongation to a substantially straight configuration elongated for translation through a microcatheter by hand pushing on the control wire, or using a pushing component engaged to the proximal end of the catheter to push on the control wire.

Further, once released, the coil device herein assumes an overlapping conical shape at one end which forms a particularly secure mount when a second end of the coil reverses on deployment to cover the narrow end of the first deployed end. As noted, once deployed from a microcatheter, the unique shape and overlapping configuration of the deployed coiled implant, provides the requisite strength to block an area of high blood flow and resulting high pressure forces. Further, the unique overlapping coiled configuration achieves the necessary engaging compressive force against surrounding tissues to maintain a permanent mount in the patient and thus avoid a life-threatening dismount.

The forgoing examples of related art and limitation related therewith are intended to be illustrative and not exclusive, and they do not imply any limitations on the invention described and claimed herein. Various limitations of the related art will become apparent to those skilled in the art upon a reading and understanding of the specification below and the accompanying drawings.

SUMMARY OF THE INVENTION

The device herein disclosed and described provides a solution to the shortcomings in prior art and achieves the above noted goals through the provision of an intravenous microcatheter deliverable coiled implant. The coiled implant is especially configured for employment in the many instances where infants with narrow blood vessels, require a device to prevent cross fluid flow in a very high blood flow area.

The memory metal formed coiled implant herein is formed with metal in a manner yielding very high tension on deployment as well as sufficiently low pressure on the interior conduit of the microcatheter used for translation of the coil to the implant site.

With the unique coil-over-coil deployed configuration of the high tension coiled implant herein, the present device is able to occlude both small and large unwanted vascular structures. However, even though the implant achieves a size and engagement to block a large area, and its unique frusto-conical wrap-over configuration concurrently provides a stable and strong mount, it still may be elongated to an enlarged configuration where it is deliverable by way of a microcatheter.

Because of the size and lack of sufficient prior art engagement structures to be used in narrow vascular structures of infants, and to remain mounted even if deployable therethrough, many of such vascular deformities such as certain coronary artery fistulas and PDAs in premature infants and newborns and children, are currently unable to be corrected using a minimally invasive transcatheter type surgical procedure. Thus, patients most in need of the most non-invasive care, newborn children and infants, have instead been subjected to more conventional surgery which is not well tolerated by adults, let alone children. Further, while other lesions can be treated with a variety of other larger low tension coils and plugs the disclosed device herein renders many of these types procedures easier.

The unique shape and high radial force of the coils herein described and shown, provide an implant which enables surgeons to perform a transcatheter type procedure on newborns and infants, rather than more invasive surgical procedures being used. Further, the high degree of control of the implant during and on release, and the ability of the high tension coiled implants to translate through microcatheters, provides such surgeons with a high degree of control and confidence the deployed coil will be in the proper position and will stay mounted after deployment.

The disclosed coiled implant, developed with extensive experimentation, has a wire cross sectional size configured to be delivered via the axial conduit of conventional microcatheters which are designed specifically for the treatment of high flow vascular lesions. The current device is formed in a rigorous, high radial force coil, which has a radial force much higher than currently available 0.025-0.027 coils. Radial force in experiments with the device herein, and with various prior art implants, is meant the amount of force required to force the device, in its elongated position, from the distal end of the delivery catheter, and into its coiled deployed shape. This measurement appears to correlate to the amount of force the coils of the deployed device provide in resisting movement of the adjacent coils away from each other. While other prior art coiled devices which were larger in diameter required just 0.2 newtons to draw the elongated component from within an axial pathway such as that of a catheter, the device herein required 0.3 newtons for such an extraction to the deployed position. This is a 50% higher amount of force required to draw the device in its elongated mode within an axial passage of a catheter, into the deployed overlapped cone shape. An equally larger amount of force is required to deflect or dislodge the coils of the device herein, from their memory position in an overlap of coiled sections.

The device is able to track through a microcatheter and upon reaching the implant site it has a highly controlled release. Because the higher tensional force of the device imparts a high frictional force against the microcatheter axial wall, the system provides a pushing mechanical mechanism designed to aid the surgeon in pushing the wire and coil through the catheter in case the microcatheter has kinks, which frequently happens. Upon deployment the memory metal of the implant, the resulting high radial force maintaining the coils adjacent to each other, forms a coil shape designed specifically for occlusion in infants and newborns using a unique second portion of the coil over a first-deployed portion of the coil configuration.

Objects, features, and advantages of the invention will be brought out further in the following part of the specification, wherein detailed description is for the purpose of fully disclosing the invention without placing limitations thereon.

In this description, the directional prepositions of up, upwardly, down, downwardly, front, back, top, upper, bottom, lower, left, right and other such terms refer to the device as it is oriented and appears in the drawings and are used for convenience only; they are not intended to be limiting or to imply that the device has to be used or positioned in any particular orientation.

Now referring to drawings inFIGS. 1-15, wherein similar components are identified by like reference numerals, there is seen inFIG. 1, a view of the microcatheter12having an axial passage through which the implant device10herein is sized for passage, in an elongated state to an implant site. At the implant site, the device10will achieve a deployed configuration as inFIG. 2, 7, or11or other deployed configuration where a first portion13of the implant device10, deploys on a first side of an aperture or opening or other vascular or arterial area to be blocked, and a second portion15of the implant device10coils around a coiled mid portion extending away from the first portion13.

Translation through the axial passage of the catheter12type device is accomplished using a control wire18. The wire18is translated through the axial passage of the catheter12to the distal exit to first extend the first portion13of the implant device10on a first side of the aperture16or passage, or opening to be blocked such as shown inFIG. 3. The first portion13shown inFIG. 3, which is also the distal end22, and as is the case with all modes of the device10, assumes its memorized shape as the wire forming the device10translates from the catheter and coils.

In filling or plugging unwanted vascular or arterial anomalies such as anomalies of origin, termination, structure, or course, such as coronary artery fistulas, and PDA's, especially in infants, the device10in deployed configuration, outside of the catheter12, achieves a coiled shape, to form a narrow mid section20in a central area of the formed implant device10, between the distal end22, and proximal end24or second portion15of the device10, which is removably engaged to release from the control wire18. This centrally located narrow mid section20, in combination with the large end section25on the pressurized side of the anomaly being filled, fills or plugs the unwanted aperture16or passage or recess or other communicative anomaly in the vascular or arterial structure.

As depicted inFIGS. 2-5 and 22-14, a particularly preferred mode of the device10forms the shape of the distal end22or first portion13of the device10to deploy, which is coiled to form a semi-planar distal end section25which is formed by inward coils from a perimeter edge starting at a distal endpoint26of the wire. During deployment of the first portion13to form the end section25, the wire coils inward to a central section27, wherein the coils rise in an axial winding23extending away from the formed end section25forming the first portion13of the device10.

During deployment of the first portion13of the device10, at a peak28distance of the axial winding23, from the end section25, the shaped metal wire reverses course. The surgeon at this point can check with a camera or visualization means to determine if the end section25is of sufficient diameter to block the intended anomaly or aperture16as referred to herein. If such is the case, the second section15may be formed by the wire extension from the distal end of the catheter12, which winds back toward the end section25by a winding around the axial winding23formed by the wire between the peak28of the windings forming the end section25. This second section15forms a diameter of the device10on the opposing side of the aperture16or other anomaly which prevents dislodgement toward the end section25, and positions the device10in an operative engagement deployed with the intended anomaly such as the depicted aperture16in tissue17between two arterial or vascular conduits.

As shown in all modes of the device10a first portion13having an end section25formed substantially larger in diameter than the diameter at the proximal end24is particularly preferred. This is because as shown inFIG. 3, allowing the wire to first communicate through the aperture16whereupon in a deployment of the first portion13the wire winds to form an end section25substantially wider than the diameter of narrow mid area20the central area of the device10allows the end section25to be tested on the pressurized side “P” inFIG. 3, and allows the mid area20to extend to substantially fill the aperture16or anomaly between two arterial and/or vascular conduits in the body. When placing the end section25on the side of the aperture16which has fluid pressure P, the fluid contacting the end section25, pushes the end section to contact the area of tissue17surrounding the communicative anomaly shown as the aperture16and substantially prevents fluid flow between the two vascular or arterial passages.

As can be seen inFIGS. 5, 9, and 13for instance, once the first portion13is deployed to form to the end section25, the wire of the formed device10follows windings along axial windings23to form a center area communicating through the anomaly such as the aperture16. At a peak28of the axial windings23extending a distance from the end section25, the memory metal wire, such as Nitinol, is pre-shaped to reverse the wind direction, back over the axial winding23toward the aperture16and end section25. This reverse winding of the second section15, renders an area of the device10on the un pressurized side of the anomaly or aperture16, wider than the aperture16to prevent dismount from the tissue17and passage in the opposite direction. This double wind of the wire, in all modes of the device10, over the axial winding23, thus renders the device10, anchored in patient tissue.

However, at any time prior to disengagement of the device1—from the guide wire18, it may be retrieved back into the axial passage of the catheter12. This gives the user, or surgeon, the ability to test the size of the end section25of the first portion13deployed, and insure that it is sufficiently wide in diameter, to plug the anomaly such as the aperture16or hole, or gap, or other unwanted arterial or vascular passage, prior to release of the second portion15. Since the larger end section25of the first portion13, will be on the pressurized side of the aperture16, is pushed against the tissue surrounding it by the pressurized fluid and prevent leakage or back flow through the anomaly such as the aperture16. Using means for depicting the implant site, the surgeon may determine the proper size of the end section25, prior to continued deployment.

As notedFIG. 1aas well as2-5and11-14, shows the particularly favored shapes of the coiled implant device10on deployment to an as-used configuration. As depicted, the end section25in the first portion13, assumes an upward angle or conical shape as the wire winds from a perimeter to a center area. This inclined surface13is preferred as testing has shown it better allows the surface31of the end section25to self-fit against the tissue17and anomaly which is not necessarily circular or even in shape, and allows portions of the surface31to fit against tissue surrounding the anomaly such as the aperture16for a good seal.

The axial windings23during deployment, rise from the surface31to the peak28and will provide a means to self-center the device10with and through the anomaly such as an aperture16and placing the surface31in communication with flesh17around it. So positioned, with the axial windings communicating through the anomaly, in all modes of the device10, the reverse wire windings forming the second portion15of the device10, in a reversing direction to encircle over the axial windings23of the first portion13of the implant device10, thereby provide an especially secure mount and ability to occlude larger areas.

FIGS. 2-5shows different views of the device10ofFIG. 1a, and shows the diameter D1at a distal end forming the end section25of the first portion13of the device, and a diameter D2of the proximal end or second portion15of the device10ofFIGS. 3-5. A currently preferred configuration of the device10ofFIGS. 2-5is with a diameter D1of 10 mm plus or minus 0.5 mm, and a diameter D2being ½ the diameter of D1or 5 mm plus or minus 0.5 mm which is depicted inFIG. 6.

FIGS. 7-9show another mode of the device10having opposing diameters D1at a first portion13of the device and D2at the second portion25of the device10, which vary from being substantially equal in size, to having one of the respective opposing sides being 25% more than the other which is shown inFIG. 10.

FIGS. 11-14depicts another mode of the device10which has a first portion13defining the end section25has a first Diameter D1, and said second portion second has a diameter d2which is substantially 1.75 times that of the second end of the second portion15of the device10in a deployed state. Again the surface31of the end section25is conical and rises at an angle from a low point at the perimeter of end section25to a high point in a center of the end section25where the axial windings23begin. In one preferred set of dimensions following this ratio, the diameter D1is 7 mm and the diameter of D2is 4 mm as shown inFIG. 15. Although other configurations following this ratio may be employed so long as the incline of the surface31is provided toward a center such as also is done inFIGS. 2-5.

Thus while experimentation has shown the above noted modes of the device10have defined measurements to the first portion and second portion diameters, which work best, other modes work well also where the first portion13defining the end section25has a diameter from 1.5 to 2.5 times the second diameter defined by the diameter of the second portion15.

This invention has other applications such as in small blood vessels of the brain of adults, as well as others, and those skilled in the art upon reading this disclosure and being educated with regard to this device and method could discover such modes of employment and such are anticipated within the scope of this application. Further, the explanation of the features of this invention does not limit the claims of this application, and other applications developed by those skilled in the art are considered to be included in this invention.

It is additionally noted and anticipated that although the device is shown in its most simple form, various components and aspects of the device may be differently shaped or slightly modified when forming the invention herein. As such those skilled in the art will appreciate the descriptions and depictions set forth in this disclosure or merely meant to portray examples of preferred modes within the overall scope and intent of the invention, and are not to be considered limiting in any manner.