US20040049210A1 - Filter apparatus for ostium of left atrial appendage - Google Patents

Abstract

A membrane applied to the ostium of an atrial appendage is disclosed. The membrane prevents blood clots in the atrial appendage from escaping therefrom and entering the blood stream which can result in a blocked blood vessel, leading to strokes and heart attacks. The membrane may be permeable or impermeable with respect to blood flow. The membrane is configured to extend over the ostium of the left atrial appendage. The membrane has an outer periphery with a dimension larger than a corresponding dimension of the ostium. Securement means is provided to secure the outer periphery of the membrane in direct engagement with the atrial wall surrounding the ostium. The securement means may located between the membrane and the atrial wall, or the securement means may extend distally from the membrane through the ostium.

Description

• This application is a divisional of application Ser. No. 09/642,291, filed Aug. 18, 2000, which is a continuation-in-part of application Ser. No. 09/614,091, filed Jul. 11, 2000, which is a continuation-in-part of application Ser. No. 09/428,008, filed Oct. 27, 1999, (now U.S. Pat. No. 6,551,303) all of which are incorporated by reference in their entirety herein. The application Ser. No. 09/614,091, filed Jul. 11, 2000 also claims the benefit of U.S. provisional application No. 60/196,454, filed Apr. 11, 2000, U.S. provisional application No. 60/206,967, filed May 25, 2000, U.S. provisional application No. 60/209,511, filed Jun. 5, 2000, and U.S. provisional application No. 60/211,896, filed Jun. 16, 2000. The application Ser. No. 09/642,291, filed Aug. 18, 2000 also claims the benefit of U.S. provisional application No. 60/196,454, filed Apr. 11, 2000, U.S. provisional application No. 60/206,967, filed May 25, 2000, U.S. provisional application No. 60/209,511, filed Jun. 5, 2000, U.S. provisional application No. 60/211,896, filed Jun. 16, 2000, and U.S. provisional application No. 60/217,125, filed Jul. 10, 2000, all of which are incorporated by reference in their entirety herein.[0001]
BACKGROUND OF THE INVENTION
• 1. Field of the Invention[0002]
• The invention relates to a membrane structure applied to or across the ostium of an atrial appendage to prevent a thrombus from leaving the atrial appendage.[0003]
• 2. Description of the Related Art[0004]
• There are a number of heart diseases (e.g., coronary artery disease, mitral valve disease) that have various adverse effects on the heart. An adverse effect of certain cardiac diseases, such as mitral valve disease, is atrial (or auricular) fibrillation. Atrial fibrillation may result in pooling of blood in the left atrial appendage. Blood pooling may also be spontaneous. When blood pools in the atrial appendage, blood clots can form and accumulate therein, build upon themselves, and propagate out from the atrial appendage into the atrium. These blood clots can then enter the systemic or pulmonary circulations and cause serious problems if they migrate from the atrial appendage and become free in the blood stream and embolize distally into the arterial system. Similar problems also occur when a blood clot extending from an atrial appendage into an atrium breaks off and enters the blood supply. Since blood from the left atrium and ventricle supply the heart and brain, blood clots from the atrial appendages can obstruct blood flow therein causing heart attacks, strokes or other organ ischemia. It is therefore necessary to find a means of preventing blood clots from forming in the atrial appendages and to prevent these blood clots, once formed, from leaving the atrial appendages to the heart, lungs, brain or other circulations of the patient which can cause heart attacks or strokes or other organ ischemia.[0005]
• U.S. Pat. No. 5,865,791 relates to the reduction of regions of blood stasis and ultimately thrombus formation in such regions, particularly in the atrial appendages of patients with atrial fibrillation. More specifically, the '791 patent relates to procedures and devices for affixing the atrial appendages in an orientation that prevents subsequent formation of thrombus. In the '791 patent, the appendage is removed from the atrium by pulling on it and by putting a loop around it to form a sack of the atrial appendage and then cutting it off from the rest of the heart.[0006]
• U.S. Pat. No. 5,306,234 relates to a method for surgically closing the passage between the atrium and the atrial appendage or severing the atrial appendage.[0007]
• Other methods of treatment include surgically removing the atrial appendages to prevent blood stasis in the atrial appendages.[0008]
SUMMARY OF THE INVENTION
• The invention provides a membrane that substantially prevents blood clots formed in the atrial appendages from exiting therefrom. Such clots may cause heart attacks, strokes and other embolic events if allowed to leave the atrial appendage and enter the bloodstream. The membrane is permanently positioned across the ostium of the atrial appendage by direct securement means to the ostium or the atrial wall adjacent the ostium.[0009]
• The membrane effectively isolates blood clots inside the left atrial appendage from leaving and entering the atrium. It may be larger than the ostium of the appendage, and extend over an area larger than the ostium. The membrane may be percutaneously delivered to the ostium of the atrial appendage by a catheter and then may be expanded for positioning across or over the ostium.[0010]
• According to one embodiment, the membrane is impermeable to blood flow. This membrane inhibits thrombus in the left atrial appendage from exiting and entering the bloodstream. The membrane also prevents blood from flowing into or out of the left atrial appendage.[0011]
• According to another embodiment, the membrane itself is permeable to permit blood flow across the membrane. By allowing the such blood flow across the membrane, the permeable structure minimizes any pressure gradient between the atrial appendage and the atrium in a controlled manner. Moreover, the permeable membrane acts as a filter in allowing blood to flow across, but substantially inhibits the passage of thrombus therethrough.[0012]
• The permeable filtering membrane may eventually become infiltrated with cells. The permeable filtering membrane allows such tissue growth which may begin along the outer periphery of the structure. Such tissue growth minimizes uncontrolled leakage about the periphery of the filtering membrane and may assist in attachment of the filtering membrane across the ostium to tissue surrounding the ostium. The filtering membrane may be coated or covered with an anticoagulant or other compounds, such as, for example, heparin, or it may be treated to prevent thrombus from forming on the filtering membrane surface, to extend its patency or until it is infiltrated with cells and/or develops an endothelial covering.[0013]
• There are many means for securing the membrane in position across the ostium of the atrial appendage. Direct securement means for the membrane may be provided by a biocompatible adhesive applied between the membrane and the ostium or the atrial wall. In this manner, the membrane can be adhered directly to the tissue. In another embodiment, direct securement is made by the use of staples, clips, sutures, wires, barbs, prongs or other methods of fixation which pass through the tissue of the ostium or atrial wall. In yet another embodiment, direct securement is achieved by the use of structure connected to the membrane which extends through the ostium and into the interior of the atrial appendage and engages the interior of the atrial appendage, wherein the interior wall of the atrial appendage may also include any portion of the ostium extending within the atrial appendage. The direct securement means may provide a self-centering feature for the membrane about the appendage ostium.[0014]
OBJECTS OF THE INVENTION
• It is an object of the invention to provide a membrane between the atrium and atrial appendage to prevent blood clots from flowing therebetween.[0015]
• It is an object of the invention to provide a membrane which is permanently implanted between the atrium and the atrial appendage by direct securement to the ostium or the atrial wall adjacent the ostium.[0016]
• It is an object of the invention to provide a membrane between the atrium and the atrial appendage which is impermeable to blood flow or the passage of thrombus.[0017]
• It is an object of the invention to provide a filtering membrane between the atrium and atrial appendage to allow blood flow across the filter, e.g., to reduce any hemodynamic pressure differential therebetween.[0018]
• It is an object of the invention to prevent blood clots from forming in the atrial appendage.[0019]
• It is an object of the invention to position across the ostium of the atrial appendage a non-thrombogenic, biocompatible surface that prevents blood clots from forming.[0020]
• It is an object of the invention to provide a permeable filtering membrane surface which may eventually become lined with endothelial or endocardial cells.[0021]
• It is an object of the invention to isolate the atrial appendage from the atrium proper with respect to the passage of thrombus with a filtering membrane, while allowing communication through which blood may flow.[0022]
• It is an object of the invention to minimally invasively prevent blood clots from forming in the atrial appendages and escaping therefrom.[0023]
• It is an object of the invention to prevent thrombus by use of heparin, other antithrombogenic substances, or other compounds on or eluted from the membrane.[0024]
• It is an object of the invention to ensure the membrane is centered across or over the ostium of the atrial appendage.[0025]
• It is an object of the invention to accurately place the membrane across or over the ostium of the atrial appendage.[0026]
• Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.[0027]
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a partial cross sectional view of a heart showing a catheter entering the left atrial appendage using a retrograde procedure from the aorta in accordance with the invention.[0028]
• FIG. 2 is a partial cross sectional view of a heart showing a catheter entering the left atrial appendage using a transeptal procedure from the femoral vein or superior vena cava in accordance with the invention.[0029]
• FIG. 3 is a partial cross sectional view of a heart showing a catheter entering the right atrial appendage from the jugular vein or optionally from the femoral vein in accordance with the invention.[0030]
• FIG. 4 is a partial cross sectional view of a portion of a heart showing an atrium and its associated atrial appendage.[0031]
• FIG. 5 is a partial cross sectional view of a delivery catheter having a disk, a spring and membrane therein in accordance with the invention.[0032]
• FIG. 6 is a schematic view of a disk, spring and membrane after being expanded out of the delivery catheter of FIG. 5 in accordance with the invention.[0033]
• FIG. 7 is a partial cross sectional view of a portion of a heart showing an atrium and its associated atrial appendage having a disk, a membrane and a spring therebetween in accordance with the invention.[0034]
• FIG. 8 is a partial cross sectional view of a portion of a heart showing an atrium and its associated atrial appendage shown in a collapsed position in accordance with the invention.[0035]
• FIG. 9 is a partial cross sectional view of a portion of a heart showing an atrium and its associated atrial appendage having a disk, a spring, a membrane and vacuum in the catheter in accordance with the invention.[0036]
• FIG. 10 is a partial cross sectional view of a portion of a heart showing an atrium and its associated atrial appendage showing an umbrella folded for entering the atrial appendage in accordance with the invention.[0037]
• FIG. 11 is a partial cross sectional view of a portion of a heart showing an atrium and its associated atrial appendage showing the umbrella opened in the atrial appendage to secure the umbrella into the wall of the atrial appendage in accordance with the invention.[0038]
• FIG. 12 is a partial cross sectional view of a portion of a heart showing an atrium and its associated atrial appendage showing the umbrella and membrane positioned across the ostium of the atrial appendage in accordance with the invention.[0039]
• FIG. 13 is a partial cross sectional view of a portion of a heart showing an atrium and its associated atrial appendage showing the atrial appendage reduced to a minimum volume by a disk and spring squeezing the appendage against a membrane in accordance with the invention.[0040]
• FIG. 14 is a perspective view of another embodiment of a filtering membrane and apparatus for installing the filtering membrane in accordance with the invention.[0041]
• FIG. 15 is a sectional view of the filtering membrane and apparatus illustrated in FIG. 14, in accordance with the invention.[0042]
• FIG. 16 is an enlarged view of a portion of the apparatus of FIG. 15 in accordance with the invention.[0043]
• FIG. 17 is a partial cross-sectional view illustrating an early stage in the installation of the apparatus of FIG. 14, in accordance with the invention.[0044]
• FIG. 18 is a partial cross-sectional view similar to FIG. 17, illustrating a later stage in the procedure in accordance with the invention.[0045]
• FIG. 19 illustrates another embodiment of the filtering membrane and apparatus for installing the filtering membrane in accordance with the invention.[0046]
• FIG. 20 is an enlarged view of the filtering membrane and apparatus illustrated in FIG. 19 in accordance with the invention.[0047]
• FIG. 21 is a planar development of the apparatus for attaching the filtering membrane illustrated in FIGS.[0048]19-20 in accordance with the invention.
• FIG. 22 is an enlarged perspective view of a portion of the apparatus of FIG. 21, in accordance with the invention.[0049]
• FIG. 23 is a planar development of the apparatus depicted in FIG. 21 in an expanded configuration, in accordance with the invention.[0050]
• FIG. 24 is a perspective view of the filtering membrane and apparatus for attaching the filtering membrane of FIG. 20, illustrated in an expanded configuration in accordance with the invention.[0051]
• FIG. 25 is an elevational view of an embodiment of the filtering membrane in accordance with the invention.[0052]
• FIG. 26 is an elevational view of another embodiment of the filtering membrane in accordance with the invention.[0053]
• FIG. 27 is an elevational view of yet another embodiment of the filtering membrane in accordance with the invention.[0054]
• FIG. 28 is an elevational view of a further embodiment of the filtering membrane in accordance with the invention.[0055]
• FIG. 29 is a partial cross-sectional view illustrating an early stage in the procedure of installing of the filtering membrane of FIGS.[0056]19-28 in accordance with the invention.
• FIG. 30 is a partial cross-sectional view similar to FIG. 29 illustrating a later stage in the procedure in accordance with the invention.[0057]
• FIG. 31 is a partial cross-sectional view similar to FIG. 30 illustrating a still later stage in the procedure in accordance with the invention.[0058]
• FIG. 32 is a view similar to FIG. 31 illustrating an alternative embodiment of the apparatus illustrated in FIGS.[0059]19-23.
• FIG. 33 is a partial cross-sectional view similar to FIG. 32 illustrating a later stage in the procedure in accordance with the invention.[0060]
• FIG. 34 is a partial cross-sectional view similar to FIG. 33 illustrating a still later stage in the procedure in accordance with the invention.[0061]
• FIG. 35([0062]a) illustrates an alternative embodiment of the apparatus illustrated in FIGS.19-20 in accordance with the invention.
• FIG. 35([0063]b) illustrates the apparatus illustrated in FIG. 35(a) in an expanded configuration in accordance with the invention.
• FIG. 36 is a view similar to FIG. 35([0064]b) illustrating another embodiment in accordance with the invention
• FIG. 37 illustrates yet another embodiment of the filtering membrane and apparatus for attaching the filtering membrane in accordance with the invention.[0065]
• FIG. 38 is an elevational view taken from[0066]direction38 of FIG. 37 in accordance with the invention.
• FIG. 39 is elevational view taken from[0067]direction39 of FIG. 37 in accordance with the invention.
• FIG. 40 is a sectional view illustrating the apparatus of FIGS.[0068]37-39 along with additional apparatus in accordance with the invention.
• FIG. 41 is a partial cross-sectional view illustrating a first installed configuration of the apparatus of FIGS.[0069]37-39 in accordance with the invention.
• FIG. 42 is a partial cross-sectional view similar to FIG. 41 illustrating a second installed configuration of the apparatus of FIGS.[0070]37-39 in accordance with the invention.
• FIG. 43 is a partial cross-sectional view illustrating another embodiment of the apparatus in accordance with the invention.[0071]
• FIG. 44 illustrates a further embodiment of the apparatus in accordance with the invention.[0072]
• FIG. 45 is an end view of the apparatus of FIG. 44 in accordance with the invention.[0073]
• FIG. 46 illustrates a still further embodiment of the apparatus in accordance with the invention.[0074]
• FIG. 47 illustrates additional apparatus for use with the apparatus of FIGS.[0075]44-46 in accordance with the invention.
• FIG. 48 is an enlarged sectional view of the apparatus of FIG. 47 in accordance with the invention.[0076]
• FIG. 49 is a partial cross-sectional view of the apparatus of FIGS.[0077]44-45 illustrating an early stage in the procedure in accordance with the invention.
• FIG. 50 is a partial cross-sectional view similar to FIG. 49 illustrating a later stage in the procedure in accordance with the invention.[0078]
• FIG. 51 illustrates yet another embodiment of the apparatus in accordance with the invention.[0079]
• FIG. 52 is an end view of the apparatus of FIG. 51 in accordance with the invention.[0080]
• FIG. 53 illustrates additional apparatus for use with the apparatus of FIGS.[0081]51-52 in accordance with the invention.
• FIG. 54 is an enlarged sectional view of the apparatus of FIGS. 51 and 53 in accordance with the invention.[0082]
• FIG. 55 is a partial cross-sectional view of the apparatus of FIG. 51 illustrating an early stage in the procedure in accordance with the invention.[0083]
• FIG. 56 is a partial cross-sectional view similar to FIG. 55 illustrating a later stage in the procedure in accordance with the invention.[0084]
• FIG. 57 illustrates another embodiment of the apparatus in accordance with the invention.[0085]
• FIG. 58 illustrates yet another embodiment of the apparatus in accordance with the invention.[0086]
• FIG. 59 is a partial cross-sectional view of the apparatus of FIG. 57 illustrating an early stage in the procedure in accordance with the invention.[0087]
• FIG. 60 is a partial cross-sectional view similar to FIG. 59 illustrating a later stage in the procedure in accordance with the invention.[0088]
• FIG. 61 is a simplified elevational view of another embodiment of the membrane in accordance with the invention.[0089]
• FIG. 62 is a side view of the membrane taken from direction[0090]62 of FIG. 61, in accordance with the invention.
• FIG. 63 is view in partial section of the membrane of FIGS.[0091]61-62 illustrating a typical use in accordance with the invention.
• FIG. 64 is view in partial section of the yet another embodiment of the membrane, illustrating a typical use in accordance with the invention.[0092]
• FIG. 65 is a simplified elevational view of still another embodiment of the membrane in accordance with the invention.[0093]
• FIG. 66 is a side view of the membrane taken from direction[0094]66 of FIG. 65, in accordance with the invention.
• FIG. 67 is view in partial section of the membrane of FIGS.[0095]65-66 illustrating a typical use in accordance with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
• Although atrial fibrillation may result in the pooling of blood in the left atrial appendage and the majority of use of the invention is anticipated to be for the left atrial appendage, the invention may also be used on the right atrial appendage and in general for placement across any aperture in the body in which blood clots are substantially prevented from escaping from the cavity and entering into the bloodstream.[0096]
• As shown in FIG. 4, a thrombus, blood clot, or emboli[0097]30 (collectively referred to as a thrombus) may occur from pooling of blood in the leftatrial appendage13 due to poor circulation of blood therein when the patient experiences atrial fibrillation. When blood pools in the leftatrial appendage13,thrombus30 can accumulate therein, build upon itself, and propagate out from the leftatrial appendage13 into theleft atrium11, thus leaving the heart and entering the blood stream. Once in the bloodstream, such thrombus can block blood flow to the heart, brain, other organs, or peripheral vessels if it becomes lodged in the arteries thereof. Heart attack, a stroke, or ischemia may result.
• To prevent[0098]thrombus30 from forming in the leftatrial appendage13, or to prevent thrombus formed therein from leaving and entering the blood stream which may cause a heart attack, a stroke or ischemia, amembrane40 is permanently attached over or across theostium20 of theatrial appendage13. Themembrane40 can be made of bicompatible materials, such as, for example, ePFTE (e.g., Gortex®), polyester (e.g., Dacron®), PTFE (e.g., Teflon®), silicone, urethane, metal fibers, or other biocompatible polymers.
• For each of the embodiments described hereinbelow, the[0099]membrane40 may be substantially impermeable with respect to the flow of blood. For an impermeable membrane, neither blood nor thrombus is permitted to flow through the membrane. As described hereinabove, this structure prevents thrombus inside the atrial appendage from entering the bloodstream and causing heart attack, stroke, or ischemia. The impermeable membrane may be fabricated from materials described above, such as polyurethane, polyester (e.g., Dacron®), ePFTE (e.g., Gortex®) in textile, braid, or substrate form. The impermeable membrane could also be comprised of a combination of two or more materials. In some cases, the outer periphery of the membrane may be supported by struts fabricated from metal (e.g., stainless steel or nitinol) or plastic, or by cells or braid. (See, e.g., FIGS. 20, 22,24,50,56). This additional structure may provide additional securement of the outer periphery of the membrane against the atrial wall surrounding the ostium in order to provide a leakproof seal.
• According to another embodiment, each of the[0100]membrane structures40 described herein may alternatively be substantially permeable with respect to the flow of blood therethrough. The permeable membrane may also act as a filtering membrane in that it will substantially inhibit thrombus from passing therethrough. The permeable filtering membrane may have pore sizes ranging from about 50 to about 400 microns. It is also contemplated that the pores may also be larger or smaller as indicated by the circumstances, provided such pores substantially inhibit thrombus from passing therethrough. The open area of the filtering membrane is preferably at least 20% of the overall surface area, although a range of about 25-60% may be preferred. The structure of the filtering membrane is preferably a two-dimensional screen, a cellular matrix, a woven or non-woven mesh, or the like. The filtering membrane may also be a permeable metal or a metal mesh of fine fibers. The filtering membrane may be coated or covered with an anticoagulant, such as heparin, or another compound, or treated to provide antithromogenic properties.
• The permeability of the filtering membrane, described above, allows blood to flow therethrough while blocking or inhibiting the passage of thrombus, clots, or emboli formed within the atrial appendage from entering the atrium of the heart and, eventually, the patient's bloodstream.[0101]
• The characteristic of allowing the flow of blood through the filtering membrane provides several advantages. For example, the left atrial appendage inherently contracts during normal cardiac function to force blood through the heart. These contractions result in blood flow through the ostium of the left atrial appendage. Allowing blood flow through the filtering membrane substantially reduces any pressure gradient that may exist between the appendage and the atrium.[0102]
• The reduction of the pressure gradient may be helpful to the patient during recovery from the implantation of the filtering membrane structure in the atrial appendage. More particularly, the heart is able to more gradually adapt to the presence of the filtering membrane when blood is permitted to flow through the membrane, and consequently through the ostium of the left atrial appendage.[0103]
• The filtering function may also reduce the risk of leakage about the periphery of the filtering membrane, or of dislodgement of the filtering membrane that may result from the exertion of pressure against the surface of the filtering membrane. Allowing the blood flow across the filtering membrane may relieve this pressure, sufficiently and in a controlled manner, to reduce such leakage or dislodgement.[0104]
• Tissue ingrowth may provide additional securement of the filtering membrane to the ostium. More particularly, the growth of tissue may occur along the outer periphery of the filtering membrane or supporting structure adjacent the ostium This tissue growth, in cooperation with the pressure relief provided by the permeable structure, may provide additional means of reducing leakage about the periphery of the filtering membrane. Tissue growth may eventually cover additional surface area of the filtering membrane.[0105]
• The[0106]membrane40 placed across or over theostium20 should be antithrombotic. In order to make the membrane antithrombotic, heparin or other anticoagulants or antiplatelet agents may be used on themembrane40.
• When[0107]permeable filtering membranes40 are used, an ingrowth of cells may eventually cover the membrane with endothelial cells. The endothelial cells present a smooth cellular wall covering the membrane which prevents thrombosis from occurring at the membrane.
• FIGS. 1 and 2 show a cross section of a human heart showing a[0108]thrombus30 in the leftatrial appendage13. The figures also show theatrial appendage ostium20 which is to have amembrane40 placed over it to prevent thethrombus30 from escaping out of theatrial appendage13 into theleft atrium11 and thus into the blood stream, which could cause a stroke, a heart attack or ischemia.
• FIG. 3 shows a cross section of a human heart showing a[0109]thrombus30 in the right atrial appendage23. The right atrial appendage23 can be treated in the same manner as the leftatrial appendage13.
• FIG. 4 shows a cross section of the[0110]left atrium11, theostium20 and the leftatrial appendage13 having athrombus30 therein
• FIG. 5 shows a[0111]delivery catheter125 containing acollapsed membrane40 and acollapsed disk130 connected to themembrane40 by aspring90 oncatheter21. Thedisk130 may be made of a flexible woven metal or a flexible woven metal with a thin permeable polymer sandwiched inside.Disk130 may also be a polymer weave. Thedisk130 is flexible and compresses or folds so it fits into thedelivery catheter125 and expands to its desired shape after release from thedelivery catheter125. Similarly,membrane40 compresses or folds to fit into thedelivery catheter125 and expands to its desired shape after release.Membrane40 is larger than theostium20. FIG. 6 shows themembrane40,disk130 andspring90 from FIG. 5 in an expanded configuration outside of thedelivery catheter125.
• FIG. 6 shows the[0112]spring90 connecting themembrane40 and thedisk130 for urging them together. In other embodiments an elastic tether or a tether with teeth and a pawl on themembrane40 to form a ratchet can also be used to pull themembrane40 and thedisk130 together. Sincemembrane40 is larger than theostium20, the outer periphery ofmembrane40 is in contact with the atrial wall surrounding the ostium.
• FIG. 7 shows the device of FIG. 5 applied to the left[0113]atrial appendage13 havingthrombus30. After the device is applied, thespring90 pulls thedisk130 toward themembrane40, collapsing the leftatrial appendage13 and trapping thethrombus30 therein as shown in FIG. 8. Thespring90 secures the outer periphery of themembrane40 in direct engagement with the atrial wall surrounding theostium20.
• FIG. 9 shows an alternate embodiment of the device in FIGS. 7 and 8 wherein the[0114]catheter21 is equipped with avacuum140 for sucking out blood andthrombosis30 found in the leftatrial appendage13. Thevacuum140 will help collapse the leftatrial appendage13 such thatspring90 need not be as large as in FIG. 7.
• FIGS.[0115]10-12 show another embodiment of the invention using an umbrella principle for securing themembrane40 against theostium20. FIG. 10 shows closed umbrella struts160 entering theostium20 of leftatrial appendage13. Themembrane40 is some distance back from the umbrella struts160 at the bottom of the range ofteeth195 onpole170. FIG. 11 shows the umbrella struts inside of the leftatrial appendage13 with thestruts160 open.Umbrella opening structure175 onpole170 pushes the struts out to the umbrella open position. Theumbrella opening structure175 can be pushed to the open position or have a spring loaded mechanism to push thestruts160 to the open position. The ends of the umbrella struts160 engage the left atrial appendage wall around theostium20 and prevent the umbrella from being withdrawn from the leftatrial appendage13. The ends of the umbrella struts160 that engage the atrial appendage wall may be blunted or have bulbs on the tips or have padding so as not to puncture the leftatrial appendage13. FIG. 12 shows the outer periphery ofmembrane40 drawn up against the atrial wall surrounding theostium20 by ratcheting the membrane alongpole170. Thepawl mechanism200 engagesteeth195 onpole170 and is moved forward to snugly position themembrane40 across theostium20 such that the outer periphery of themembrane40 is in direct engagement with the atrial wall surrounding the ostium.
• FIG. 13 shows the left[0116]atrial appendage13 compressed such that the volume of the atrial appendage is reduced to almost nothing. With the volume reduced the atrial appendage will not have a large volume of blood which can produce a thrombus. In the embodiment showndisk130 andspring90 pull the leftatrial appendage13 towardmembrane40. Although FIG. 13 shows the use of adisk130 andspring90 to act on the left appendage, any method to reduce the volume of the atrial appendage as much as possible may be used.
• As shown in FIG. 13 the[0117]membrane40 is much larger than theostium20. Theoversized membrane40 may alternatively be used in all embodiments to ensure that theostium20 is completely covered. Thespring90 secures the outer periphery of themembrane40 in direct engagement with the atrial wall surrounding theostium20. Themembrane40 has a structure which blocks or substantially inhibits thrombus, clots or emboli from entering the atrium, and eventually, the bloodstream of the patient.
• FIGS.[0118]14-18 show another embodiment of the invention wherein the outer periphery of themembrane40 is secured in direct engagement with the atrial wall surrounding theostium20 by an expandable structure, such asballoon structure402. As illustrated in FIG. 15,balloon structure402 may be manufactured from polymeric materials or similar materials known in the art.Tube404 communicates with the internal cavity ofballoon structure402 for introducing saline or other appropriate fluid into theballoon structure402.Membrane40 is attached totube404 in any appropriate manner, such as adhesive, sutures, or other means, and is provided with anaperture406 which permits access to an end portion oftube404, which acts as aballoon introduction port408 to allow the introduction of fluid into theballoon structure402.
• FIG. 14 also illustrates a structure for introducing fluid into the[0119]balloon structure402, such ascatheter apparatus410.Catheter apparatus410 includes anoutlet port412 at its distal end portion for ejecting fluid from thecatheter apparatus410.Outlet port412 may be connected to theballoon introduction port408, which in turn communicates with the internal lumen oftube404 and the interior ofballoon structure402.
• FIG. 15 illustrates the[0120]membrane40, theballoon structure402, thetube404, together with thecatheter410 attached to thetube404, in a compacted configuration within adelivery tube422. More particularly,balloon structure402 is in its collapsed state andmembrane40 is flexible and compressed or folded to fit into thedelivery tube422.Membrane40 is designed to expand into a disc-like shape after release fromtube422. FIG. 16 illustrates the certain structures pertinent to the interconnection ofcatheter410 withtube404. More particularly,outlet port412 ofcatheter410 may be provided withnarrow tube424 which is received withinballoon introduction port408 and maintains avalve426 in an open position whenoutlet port412 is connected toinlet port408. Whenoutlet port412 is removed fromballoon introduction port408,valve426 may close to prevent fluid from leavingballoon structure402, as shown in FIG. 16.
• [0121]Delivery tube422 may be introduced into the venous or arterial system at an appropriate location, and advanced to into the atrium of the heart with appropriate steering and visualization apparatus (not shown).
• FIG. 17 illustrates a later stage in the installation procedure wherein the[0122]membrane40, theballoon structure402, thetube404, and thecatheter410 have been advanced from the delivery tube422 (not shown in FIG. 17). Theballoon structure402 is positioned within the leftatrial appendage13 such that the outer periphery ofmembrane40 is positioned adjacent the atrial wall surrounding theostium20. Fluid is subsequently introduced into thecatheter410 which passes throughtube404 to expand theballoon structure402, as illustrated in FIG. 18. Theballoon structure402 expands within theatrial appendage13 and secures themembrane40 in position. The valve mechanism426 (not shown in FIG. 18) ofballoon introduction port408 prevents the fluid from passing out of theballoon structure402 when thecatheter410 is detached from theballoon port408 and subsequently removed from the atrium. As described above,membrane40 may have an impermeable structure which prevents thrombus for exiting theatrial appendage13, but which also prevents blood flow through themembrane40.Membrane40 may alternatively be a permeable structure which allows blood to flow therethrough but which blocks or substantially inhibits thrombi, clots or emboli from exiting theatrial appendage13; and entering the bloodstream of the patient.
• FIGS.[0123]19-31 illustrate yet another embodiment for attaching the membrane across theostium20 of the leftatrial appendage13. FIG. 19 illustrates themembrane40, theattachment apparatus440 for securing themembrane40 across theostium20 of theatrial appendage13, andcatheter apparatus442 for installing theattachment apparatus440 andmembrane40. As FIG. 20 illustrates,attachment apparatus440 andmembrane40 may be initially in a compacted configuration.Attachment apparatus440 is preferably an expandable tubular apparatus having aninitial diameter444 of about 1-3 mm and aninitial length446 of about 0.5-6 cm. Attachment apparatus is preferably manufactured from a flexible material such as stainless steel, nitinol, nylon, polyester, PET, or polyethylene.Attachment apparatus440 may be expanded by an expansion structure, such asballoon structure452 ormechanical expansion structures472 or482. Alternatively,attachment apparatus440 may be self-expanding, such that it is normally biased in an expanded position, such as that described with respect to FIG. 24, and deployed in a constrained position such as that described with respect to FIG. 20. Apparatus for constraining the self-expanding apparatus is typically a tube.
• [0124]Membrane40 is attached toattachment apparatus440 at the proximal end thereof, in a loosely fitted, somewhat conical configuration and defines acentral opening448, which allows thecatheter450 ofcatheter apparatus442 to pass throughmembrane40, as will be described in greater detail herein. Alternatively,membrane40 may also cover a greater portion of thelength446 of theattachment apparatus440, ormembrane40 may cover theentire attachment apparatus440 in a substantially sock-like fashion.Membrane40 may be fabricated from a material that also has elastic characteristics which may expand from a first size to a second size.
• [0125]Catheter450 supplies expansion fluid, such as saline or contrast medium, into expandable structure, such asballoon structure452, which is positioned within the interior lumen ofattachment apparatus440 in order to radially expandattachment apparatus440 when it is positioned within theatrial appendage13.Balloon structure452 may include a distal,atraumatic tip portion454, e.g., a flexible helical coil or soft plastic tip.
• FIGS. 21 and 23 illustrate planar developments of[0126]attachment apparatus440. The structure ofattachment apparatus440 preferably allows thelength446 of the apparatus in its initial configuration (FIG. 21) to remain substantially constant with respect to thelength456 in its expanded configuration (FIG. 23). In order to achieve this expansion while maintaining substantially constant length,attachment apparatus440 is provided with a configuration having severalserpentine segments458,460, and462. Adjacent serpentine segments are interconnected by a plurality of longitudinal struts, e.g., rings457 and460 are interconnected bystruts464 and rings460 and462 are interconnected bystruts466. A plurality ofmembers470 at the distal end portion ofapparatus440 may provide an attachment point for themembrane40. More particularly,radial members471 are configured to extend radially outward (FIG. 22) to provide a location for attachment of the outer periphery ofmembrane40 and to provide a surface for attachment to the atrial wall. As will be described herein,radial members471 may be expanded to the radially outward configuration by an expansion member such as a balloon. In one embodiment, the materials or thickness ofmembers471 may be selected in order to allowmembers471 to expand to a greater extent than the rest of theattachment member440. Alternatively,members471 may be fabricated from a self-expanding material, such as, e.g., nitinol, wherein members are normally biased in the radially outward configuration.
• FIG. 24 illustrates[0127]attachment member440 in an expanded configuration, whereinlength456 remains substantially constant with respect to thelength446 of the configuration illustrated in FIG. 30.Diameter472 is substantially larger than diameter444 (FIG. 20) in order to secure itself against the interior of theatrial appendage13 and to securemembrane40 in direct engagement with the atrial wall surrounding theostium20, as will be described herein.Members471 extend radially outward, and provide structure to the outer periphery ofmembrane40.
• FIGS.[0128]25-28 illustrate several embodiments of themembrane40. As described above,catheter450 passes throughopening458 inmembrane40 in order to supply expansion fluid toexpandable balloon structure452. Afterballoon structure452 has expanded theattachment apparatus440 to the expanded configuration illustrated in FIG. 24, it may be necessary to removeballoon structure452 by passing theballoon structure452 proximally throughmembrane40, and more particularly, throughopening458. The embodiments ofmembrane40 illustrated in FIGS.25-28 may facilitate the passage ofballoon structure452, or other interventional devices therethrough.
• FIG. 25 illustrates[0129]membrane40ahaving a composite construction comprising filtering section474aand elastic section476a. The filtering section474ais fabricated from a filtering material that provides the function of filtering the blood to allow the blood to pass therethrough while blocking or substantially inhibiting the passage of clots, thrombus or emboli therethrough, as described above. The elastic section476ais fabricated from an elastic material, e.g., silicone, urethane or other similar material, that stretches to enlarge opening458ato allow theballoon structure452 or other intervention devices, such as, e.g., wires, catheters or the like, to pass therethrough and to subsequently return to its initial size. The initial size of aperture458aprovides similar characteristic to inhibit clots, thrombus or emboli from passing through458aas filtering material of filtering section474a. In this configuration, elastic material476aextends substantially across the entire diameter472aof themembrane40a.
• [0130]Membrane40b(FIG. 26) is constructed with afiltering section474b(i.e., the same material as filtering section474a) and anelastic section476b(i.e., the same elastic material as elastic section476a). Inmembrane40b, thefiltering section474bsubstantially concentrically surrounds theelastic section476b. Theelastic section476bis provided with anopening458bthat expands to allow theballoon structure452 or other interventional devices to pass therethrough and to return to initial size in order to provide substantially the same characteristic of inhibiting the passage of thrombus, clots and emboli from passing therethrough as the filtering material of thefiltering section474b.
• [0131]Membrane40c(FIG. 27) is constructed with afiltering section474c(i.e., the same material as filtering section474a) and anelastic section476c(i.e., the same elastic material as elastic section476a). Inmembrane40c, thefiltering section474csubstantially concentrically surrounds an elastic section, such as substantiallyelliptical section476c. Theelastic section476cis provided with an aperture, such as aslit458cthat expands to allow theballoon structure452 or other interventional devices to pass therethrough and to return to initial size to provide substantially the same characteristic of inhibiting the passage of thrombus, clots and emboli from passing therethrough as the filtering material of thefaltering section474b.
• [0132]Membrane40d(FIG. 28) may be fabricated from the same material as filtering section474a, above, in several sections, such assections475dand477d, which overlap atregion479dto form an opening therethrough forballoon structure452 or other interventional devices. It is further contemplated that three or more sections of filtering material may be used in an overlapping configuration, in a manner similar to, for example, the “aperture” configuration of an optical device. Theballoon structure452 may be passed through the opening betweensections475dand477d. After theballoon structure452 is removed, the overlapping structure substantially closes the opening and provides substantially the same characteristic of inhibiting the passage of thrombus, clots and emboli from passing therethrough as the filtering material of thefiltering sections475dand477d.
• FIGS.[0133]29-31 illustrate the procedure for installingattachment apparatus440 andmembrane40 in theatrial appendage13. In an initial step (FIG. 29),balloon structure452, along withattachment apparatus440 are inserted into theatrial appendage13 in its initial, compact configuration. In FIG. 30, expansion fluid is passed throughcatheter450 and exits throughport453 to fill the interior ofballoon structure452.Balloon structure452 expands, thereby radially enlargingattachment apparatus440, as described with respect to FIGS.21-24, above. In a preferred embodiment,proximal portion455 ofballoon452 is constructed to expand to a greater extent in order to deflectmembers471 radially outward. Alternatively,members471 may be constructed to expand to a greater extent than the rest of theattachment member440 when expanded byballoon452. In another embodiment,members471 may be fabricated from a self-expanding material, such as, e.g., nitinol, whereinmembers471 are normally biased in the radially outward configuration. Consequently, the outer periphery ofmembrane40 is expanded to be in direct contact with the atrial wall surrounding theostium20.Members471 provide additional support to provide a good seal with the edge of themembrane40.
• As illustrated in FIG. 31,[0134]attachment apparatus440 engages the interior of theatrial appendage13, thereby securing themembrane40 in position across theostium20, such that the outer periphery ofmembrane40 is in direct engagement with the atrial wall surrounding theostium20.Balloon structure452 may be removed from theatrial appendage13 by returning theballoon structure452 to its initial compact configuration (e.g., by draining the expansion fluid therefrom) and withdrawing the balloon structure proximally throughopening458. As described above with respect to FIGS.25-28, the membrane may be fabricated with an elastic portion which expands to permit the withdrawal of the balloon structure therethrough, and which subsequently reduces in size to inhibit the passage of thrombi, clots and emboli therethrough into the atrium. Thecatheter structure442 may be subsequently removed from the patient. Alternatively, theballoon structure452 may remain within theatrial appendage13 following expansion ofattachment apparatus440 and subsequent return of theballoon structure452 to its initial compact configuration. For example,catheter450 may be detachable fromballoon structure452 in a manner similar to the configuration ofcatheter410 and tube404 (FIG. 16). Alternatively,attachment structure440 may be manufactured from a self-expanding material, such as nitinol, wherein attachment structure is normally biased in a configuration such as that shown in FIG. 24. In order to install theattachment structure440 within theatrial appendage13, theattachment structure440 may be constrained in a tube. Theattachment structure440 may subsequently be deployed from the tube and permitted to self-expand to a configuration similar to that shown in FIG. 31.
• FIGS.[0135]32-34 illustrate another embodiment of the invention.Attachment apparatus460 andballoon apparatus462 are substantially the same asattachment apparatus440 andballoon apparatus452, described hereinabove, with the differences noted below.Attachment apparatus460 may be provided with a plurality ofengagement members464, such as prongs, hooks, or the like, in order to engage and/or pierce the wall of the atrial appendage to provide additional securement of theattachment apparatus460.Balloon structure452 may be used in connection withattachment apparatus460. Alternatively,balloon structure462 may be provided having a distal end portion which is configured to expand to a greater extent than the proximal portion thereof (FIG. 33). This greater expansion of theballoon structure462 provides additional force in the area of theengagement members464 to drive them into the wall of the atrial appendage13 (FIG. 34).
• FIGS.[0136]35-36 illustrate additional embodiments of expandable structures for radially enlarging the attachment apparatus440 (or460) within the atrial appendage. Instead of, or in addition to balloon structures (such as balloon structure452), it is also contemplated that mechanical expansion structures may be particularly useful. FIGS.35(a)-(b) illustrate amechanical expansion structure472 which may be used to radially expandattachment apparatus440. As shown in FIG. 35(a),mechanical expansion structure472 may have a compact configuration wherein a plurality ofcontact members474 define adiameter476 that enables the structure to be inserted within theattachment apparatus440. As illustrated in FIG. 35(b),mechanical expansion structure472 also has an expanded configuration, whereincontact members474 are further spaced apart to define alarger diameter477 which radially enlarges the attachment apparatus to the configuration illustrated in FIGS.21-24 and30-31. A linkage configuration may includelinkage members478 andsleeve479.Sleeve479 is provided with internal threading (not shown) which engagesexternal threading480 on a portion ofdrive screw481. Angular rotation of drive screw481 (as indicated by the arrow) provides longitudinal movement ofsleeve479 which cooperates withlinkage members478 to controllably move thecontact members474 between the compact and expanded configurations.
• FIG. 36 illustrates[0137]mechanical expansion structure482, which is substantially identical tomechanical expansion structure472.Sleeve489 interacts withlinkage members478 to controllably movecontact members474, as described above with respect tosleeve479.Sleeve489 is longitudinally slidable with respect toelongated member491. A locking structure (not shown) may also be provided to fix the position of sleeve489 (and thus contact members474) with respect toelongated member491.
• [0138]Mechanical expansion structures472 and482 may remain in theatrial appendage13 following the expansion of attachment apparatus440 (or460). A portion of thedrive screw481 orelongated member491 may be detachable from theexpansion structures472 or482, respectively (not shown). Alternatively, apparatus substantially similar tomechanical expansion structures472/482 may be useful as supporting structures formembrane40. According to this embodiment,membrane40 may be attached to an end portion ofstructure472/482, e.g., by attachingmembrane40 to end portions ofcontact members474 or by substantially enclosingcontact members474 andlinkage members478. Thestructure472/482 may be positioned in theatrial appendage13 and expanded as described above, such thatmembrane40 extends across theostium20 to allow blood to pass therethrough while inhibiting the passage of thrombus through themembrane40.Drive screw481 orelongated member491 may be subsequently detached from theapparatus472/482.
• FIGS.[0139]37-39 illustrate another embodiment of the invention.Membrane40 may be installed in theatrial appendage13 and held therein byattachment apparatus500, which preferably consists of a pair offlexible wire portions502aand502b, which are preferably constructed of a material such as nitinol or Elgiloy or stainless steel and having a wire diameter of approximately 0.005 to 0.020 inch. Eachwire portion502a/502bmay include acurved portion504a/504b, a pair ofsupport members506a/506band a plurality ofengagement members508. Thecurved portions504a/504bdefine a substantially closed portion for mounting themembrane40. Themembrane40 is attached with sutures, adhesive, or other appropriate means. Theengagement members508 are configured to engage the interior of theatrial appendage13 to secure themembrane40 in position across theostium20, as will be described herein. Theengagement members508 may be provided withatraumatic end portions510.
• FIG. 40 illustrates[0140]attachment apparatus500 andmembrane40 in a compacted configuration for installation in theatrial appendage13. Preferably, adelivery catheter apparatus520 is used to introduce theattachment apparatus500 andmembrane40 to the atrial appendage. Thecurved portions504a/504bare deflected proximally toward parallelism with the longitudinal axis of thecatheter520, and theengagement members508 are deflected distally toward parallelism with the longitudinal axis. Aninner member522 is slidably received within the interior ofcatheter520 and may be moved relatively longitudinally with respect tocatheter apparatus520 in order to deploy and install theattachment apparatus500 andmembrane40.
• FIGS.[0141]41-43 illustrated several options for installing the membrane across theostium20. As illustrated in FIG. 50, thecurved portions504a/504bare positioned within the walls of theostium20 itself. Theengagement members508 provide additional support by engaging the interior of the atrial appendage. Alternatively, thecurved portions504a/504bare positioned outside the ostium within the atrium.Engagement members508 retain the outer periphery ofmembrane40 in direct engagement with the atrial wall surrounding theostium20. According to yet another alternative embodiment,engagement member508 are provided with sharpenedbarb end portions512 which engage and/or pierce the wall of the atrial appendage to secure the membrane in position (FIG. 43).
• FIGS.[0142]44-45 illustrate another embodiment of the invention.Attachment apparatus650 provides a first plurality ofstrut wires652 that extend distally and radially outward from asupport ring654 toward thedistal end portion656 of theattachment apparatus650, and a second plurality ofstrut wires658 that extend proximally and radially outward fromsupport ring654 toward theproximal end portion660. Thestrut wires652/658 may be constructed from an alloy, such as nitinol, having shape memory characteristics. Thesupport ring654 maintains thestrut wires652/658 in the proper configuration and may be made of radiopaque materials, such as, e.g., platinum to provide fluoroscopic imaging of the device position. Thestrut wires652 may be provided withbarbs662 or other methods for attachment to the interior of the atrial appendage. Thestruts652/658 are configured to engage the walls of the ostium on the inner and outside sides thereof, respectively.
• The[0143]strut wires658 may serve as a membrane mounting structure. Themembrane40 is attached to strutwires658 and provides the characteristics described above. In one embodiment, themembrane40 is permeable wherein blood is allowed to pass through themembrane40, but thrombi, clots, and emboli are inhibited from passing therethrough. Alternatively, themembrane40 may be impermeable to the flow of thrombus as well as blood. Themembrane40 may be connected to the strut wires602 using adhesive, sutures, encapsulation or other means.
• Another embodiment of the invention is illustrated in FIG. 46.[0144]Attachment apparatus670 is constructed of braided or woven mesh material rather than thestrut wires652/658 described with respect to FIGS.44-45. Thedistal portion672 is configured to engage the wall of the atrial appendage adjacent the inner portion of the ostium, and theproximal portion676 is configured to engage the outer portion of the ostium, and theneck portion674 is disposed therebetween. The braided or woven self-expanded mesh material ofattachment apparatus670 has similar filtering characteristics asmembrane40, or alternatively, a membrane is attached to the mesh material to provide those characteristics.
• FIGS.[0145]47-48 illustrate apparatus for delivering and installing theattachment apparatus650 andmembrane40 and/orattachment apparatus670. Thecatheter apparatus620 includes anouter sheath622 and aninner member624 slidably received within the interior ofouter sheath622. Theouter sheath622 andinner member624 may be fabricated from materials, such as polymers, that are sufficiently flexible to negotiate the anatomy, yet sufficiently rigid for relative longitudinal movement to deploy and position the attachment apparatus600.Inner member624 may have adistal end portion626 and ashoulder portion628.Strut wires652 of apparatus650 (ordistal portions672 of apparatus670) are deflected distally toward parallelism with the longitudinal axis of thecatheter device620 and retained in the deflected configuration by theouter sheath622. Similarly, strut wires658 (or proximal portions676) are deflected proximally toward parallelism with the longitudinal axis and retained in this configuration by theouter sheath622. In order to deploy the attachment apparatus600, theouter sheath622 is moved longitudinally relative to theinner member626. Theshoulder portion628 retains theattachment apparatus650/670 in position. Upon retraction of theouter sheath622, the shape memory characteristics of thestrut wires652/658 (orportions672/676) cause the apparatus to return to a shape approximating that of FIG. 44 (or FIG. 46).
• FIGS.[0146]49-50 illustrate the installation ofattachment apparatus650/670 andmembrane40 in greater detail. As illustrated in FIG. 49, thecatheter device622 is advanced partially within theatrial appendage13. Theouter sheath622 may be retracted proximally, which permits thestrut wires652 to extend radially outwardly. The physician may use the radiopaque characteristics of thering654 in order to properly position thering654 within theostium20. Further proximal retraction of theouter sheath622 allows thedistal strut wires652 and theproximal strut wires658 to extend radially outward and engage the interior of the atrial appendage13 (FIG. 50). Thebarbs662 may engage and/or pierce the wall of the atrial appendage to provide increased stability of the attachment apparatus600. Themembrane40 is consequently positioned across theostium20 such that the outer periphery ofmembrane40 is secured in direct engagement with the atrial wall surrounding the ostium. In one embodiment, themembrane40 is impermeable and does not permit blood or thrombus to flow, whereas a filtering membrane may be used to allow blood to pass through the membrane, while substantially inhibiting thrombi, clots, and emboli from exiting theatrial appendage13.Struts658 provide additional securement in order to maintain a leakproof seal betweenmembrane40 and the atrial wall surrounding theostium20.
• FIGS.[0147]51-52 illustrate yet another embodiment of the invention.Attachment apparatus700 provides a plurality ofstrut wires702 that extend radially outward from asupport ring704. Afirst portion706 of eachstrut wire702 extends towards theproximal end portion708 of theattachment apparatus700, and asecond portion710 of eachstrut wire702 extends towards thedistal end portion712. Thedistal portion710 of eachstrut wire702 may be provided with a sharpenedbarb tip714 or other methods for attachment to the interior of the atrial appendage. Thestrut wires702 are constructed from an alloy, similar to material used for strut wires602, above. Thesupport ring704 maintains thestrut wires702 in the proper configuration and is substantially similar to support ring604, above. Theproximal portions706 anddistal portions710 ofstrut wires702 are configured to engage the walls of the ostium on the outer and inner sides thereof, respectively.
• The[0148]membrane40 is attached toproximal portions706 ofstrut wires702 and may provides the filtering characteristic described above, wherein blood is allowed to pass through themembrane40, but thrombi, clots, and emboli are inhibited from passing therethrough. Alternatively,membrane40 may be impermeable to both blood and thrombi. Themembrane40 may be connected to thestrut wires702 using adhesive, sutures, encapsulation or other means.
• FIGS.[0149]53-54 illustrate apparatus for delivering and installing theattachment apparatus700 andmembrane40. Thecatheter apparatus620 is described above with respect to FIGS.47-48.Strut wires702 are deflected towards parallelism with the longitudinal axis of thecatheter device620 and retained in the deflected configuration by theouter sheath622. In order to deploy theattachment apparatus700, theouter sheath622 is moved longitudinally relative to theinner member626. Theshoulder portion628 retains theattachment apparatus700 in position. Upon retraction of theouter sheath622, the shape memory characteristics of thestrut wires702 causes the apparatus to resume the shape approximating that of FIG. 51.
• FIGS.[0150]55-56 illustrate the installation ofattachment apparatus700 andmembrane40 in greater detail. As illustrated in FIG. 55, thecatheter device622 is advanced partially within theatrial appendage13. Theouter sheath622 may be retracted proximally, which permits thedistal portions710 ofstrut wires702 to extend radially outwardly. Further proximal retraction of theouter sheath622 allows thedistal portions710 to engage the interior of theatrial appendage13 and theproximal portions706 to engage the outer portion of the ostium20 (FIG. 56).Struts706 provide additional securement in order to maintain a leakproof seal betweenmembrane40 and the atrial wall surrounding theostium20. Thebarbs714 may engage and/or pierce the wall of the atrial appendage to provide increased stability of theattachment apparatus700. Themembrane40 is consequently positioned across theostium20, such that the outer periphery of the membrane is secured in direct engagement with the atrial wall surrounding theostium20.Struts706 provide additional securement of the membrane to the atrial wall to provide a leakproof seal. A court order should be obtained in order to allow blood to pass through the membrane, while substantially inhibiting thrombi, clots, and emboli from exiting theatrial appendage13.
• FIGS.[0151]57-58 illustrate additional embodiments of the invention.Attachment apparatus750 includes a plurality ofstrut wires752 that extend radially outward and distally from asupport member754 towards thedistal end portion756. Eachstrut wire752 may be provided with a sharpenedbarb tip758 or other methods for attachment to the interior of the atrial appendage. Thestrut wires702 are constructed from an alloy, similar to the material used for strut wires602, above. Thesupport member754 maintains thestrut wires752 in the desired configuration.
• The proximal end portion of[0152]support member754 supports a curvedmembrane mounting structure760 that defines a substantially closed curve. Themembrane40 is attached tomembrane mounting structure760 and may provide the filtering characteristic described above, wherein blood is allowed to pass through themembrane40, but thrombi, clots, and emboli are inhibited from passing therethrough. Themembrane40 may alternatively be impermeable to blood flow and the passage of thrombi. Themembrane40 may be connected to themembrane mounting structure760 using adhesive, sutures, encapsulation or other means.
• The[0153]attachment apparatus770, illustrated in FIG. 58 is substantially identical toattachment apparatus750, with the differences noted herein. For example, the proximal end portion ofsupport member754 supports amembrane mounting structure772 having a spiral configuration. Themembrane40 is attached to spiral mountingstructure772 substantially as described above with respect tomembrane mounting structure760, above. The spiral configuration may, e.g., assist in reducing the mounting structure to a compacted configuration during installation.
• FIGS.[0154]59-60 illustrate the installation of attachment apparatus750 (or770) andmembrane40 in theatrial appendage13.Catheter apparatus780 is provided for delivering and installing theattachment apparatus750 andmembrane40. Thecatheter apparatus780 is similar tocatheter apparatus620 described above with respect to FIG. 55.Catheter apparatus780 includes anouter sheath782 and aninner member784.Inner member784 preferably has anengagement surface785 on a distal end portion thereof. During installation,strut wires752 are deflected towards parallelism with the longitudinal axis of thecatheter device780 and retained in the deflected configuration by the outer sheath782 (not shown in FIG. 59). Similarly, the membrane mounting portion760 (or772) is folded, rolled or otherwise compacted insideouter sheath782 as illustrated in FIG. 59.
• In order to deploy the[0155]attachment apparatus750, thecatheter device780 is advanced partially within theatrial appendage13. Theouter sheath782 may be retracted proximally, which permits thestrut wires752 to extend radially outwardly due to its shape memory characteristics, as shown. Theinner member784 retains theattachment apparatus750 in position.
• As illustrated in FIG. 60, further proximal retraction of the[0156]outer sheath782 allows thestrut wires752 to extend radially outward and engage the interior of the atrial appendage. Thebarbs758 may engage and/or pierce the wall of the atrial appendage to provide increased stability of theattachment apparatus700. The membrane mounting structure760 (or772) is likewise permitted to return to its disc-like configuration, such thatmembrane40 is positioned across theostium20 such that the outer periphery of themembrane40 is secured in direct engagement with the atrial wall surrounding the ostium. Themembrane40 may be permeable in order to allow blood to pass through the membrane, while substantially inhibiting thrombi, clots, and emboli from exiting theatrial appendage13. Alternatively, themembrane40 may be impermeable to blood flow and the passage of thrombus.
• FIGS.[0157]61-67 illustrate additional embodiments of the invention whereinmembrane40 is sized to cover theostium20 of the atrial appendage and secured in direct engagement with the atrial wall surrounding the ostium.Membrane40 is thus provided with a diameter or other dimension that is larger than the diameter or corresponding dimension of theostium20 in order to entirely cover the ostium. More particularly,membrane40 defines an outer periphery which is secured in direct engagement with the ostium or the atrial wall surrounding the ostium.
• As illustrated in FIGS.[0158]61-62,membrane40 is provided with a plurality ofengagement members400, which may be attached to and positioned about the outer periphery ofmembrane40, and which may haveshank portions402 and barbed free ends404 which in this case may extend radially outward from theengagement members400.
• As shown in FIG. 63,[0159]membrane40 is installed to coverostium20.Engagement members400 pierce the wall of theostium20 or the atrial wall surrounding the ostium to attach themembrane40 directly to theostium20 or the atrial wall surrounding the ostium. Barbed free ends404 prevent theengagement members400 from being withdrawn from the wall, and assists in securing themembrane40 in position as shown in the FIG.Membrane40 has a structure which blocks thrombus from leaving the atrial appendage and entering the bloodstream. A filtering permeable membrane may alternatively be used, which allows blood to flow through while substantially inhibiting thrombus.
• FIG. 64 illustrates another embodiment wherein the[0160]membrane40 covers theostium20 of theatrial appendage13. A biocompatible tissue adhesive420, such as fibrin glue or cyanoacrylate or a similar material, may be applied about the outer periphery of the membrane and used to attach themembrane40 directly to theostium20 or the wall of the atrium surrounding theostium20.Membrane40 blocks thrombus from leaving the atrial appendage and entering the bloodstream. A filtering permeable membrane may alternatively be used, which allows blood to flow through while substantially inhibiting thrombus.
• FIGS.[0161]65-66 illustrate still another embodiment of the invention whereinmembrane40 is provided with a plurality ofengagement members430. Each ofengagement members430 is mounted about the periphery ofmembrane40, and has an elongatedshank portion432 that extends distally longitudinally and a barbedfree end434 that may extend radially outward from the elongatedshank portion432.Shank portion432 is substantially longer thanshank portions402 described above with respect to FIGS.61-63.Engagement members430 define aspacing436, or the distance betweenopposite engagement members430, exclusive of the radial projection of the barb-like free ends434, that is similar in size to the interior dimensions of theostium20. This spacing436 betweenengagement members430 located on opposite sides of themembrane40 provides the feature of centering the engagement members within the interior of theostium20 and theatrial appendage13.
• As shown in FIG. 67,[0162]membrane40 is installed to coverostium20.Elongated shank portions432 extend a distance into theostium20 or theatrial appendage13 and assist in centering themembrane40 within theostium20. Barbed free ends434 engage the interior wall of theatrial appendage13 to prevent theengagement members430 from being withdrawn from the wall, and secure themembrane40 in direct engagement with theostium40 or the atrial wall surrounding theostium40 as shown in the FIG.Membrane40 has a structure which blocks thrombus from leaving the atrial appendage and entering the bloodstream. A filtering permeable membrane may alternatively be used, which allows blood to flow through while substantially inhibiting thrombus.
• The devices described above may be percutaneously delivered to the left and right[0163]atrial appendages13,23 respectively. The devices may have materials in them which enhance visualization or imaging by ultrasound, x-ray or other means making it easier for the device to be implanted and accurately centered with respect to theostium20 of theatrial appendage13. This may consist of small beads placed strategically on the membrane, the connecting elements, or on the anchors. Referring to FIG. 1catheter21 is seen entering the heart by way of theaorta12 to theleft ventricle16 passing through themitral valve17 and then entering the leftatrial appendage13 to apply themembrane40 in one of the embodiments as disclosed above. In FIG. 2 thecatheter21 enters the heart from the femoral vein, passes through theinferior vena cava18 to the right atrium and then passes through thefossa ovalis19 or through theseptum29 into theleft atrium11 and then approaches the leftatrial appendage13 to apply themembrane40 thereto. FIG. 3 shows thecatheter21 being applied to the right atrial appendage23.Catheter21 may enter the heart through thejugular vein28 or the femoral vein to theinferior vena cava18.
• It is understood that the invention may be practiced with numerous means of attaching the[0164]membrane40 across theostium20 of theatrial appendages13 and23. All of the above embodiments shown and discussed for the leftatrial appendage13 are also useable on the right atrial appendage23. Any combination of the attachment means with adhesives, prongs, cylindrical structures, anchors, disks, tethers or springs may be used. The membrane may penetrate the atrial appendage and provide a means to securely lock the membrane device into place. If permeable characteristics are preferred by the physician, other means of providing a membrane for allowing blood flow therethrough and substantially inhibiting blood clots from exiting out of the atrial appendages not listed herein may also be used.
• Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.[0165]

Claims (16)

What is claimed is:

1. Apparatus for attachment over an ostium of a left atrial appendage in a patient, comprising:

a membrane configured to extend over the ostium of the left atrial appendage, the membrane having an outer periphery with a dimension larger than a corresponding dimension of the ostium; and

securement means to secure the outer periphery of the membrane in direct engagement with the atrial wall surrounding the ostium.

2. The apparatus defined inclaim 1, wherein the securement means is located between the outer periphery of the membrane and the atrial wall surrounding the ostium.

3. The apparatus defined inclaim 2, wherein the securement means comprises an adhesive applied between the outer periphery of the membrane and the atrial wall surrounding the membrane.

4. The apparatus defined inclaim 3, wherein the adhesive is cyanoacrylate.

5. The apparatus defined inclaim 2, wherein the securement means comprises a plurality of engagement members attached to the membrane at a plurality of locations about the outer periphery of the membrane.

6. The apparatus defined inclaim 5, wherein the engagement members are configured to penetrate the atrial wall surrounding the ostium.

7. The apparatus defined inclaim 6, wherein the engagement members each comprise a barbed configuration to engage the atrial wall surrounding the ostium to inhibit removal of the engagement member from the atrial wall.

8. The apparatus defined inclaim 5, wherein the engagement members each comprise a shank portion extending distally from the outer periphery of the membrane and at least partially into the ostium.

9. The apparatus defined inclaim 8, wherein the engagement members mounted on opposite sides of the membrane define a spacing substantially identical to an interior dimension of the ostium.

10. The apparatus defined inclaim 8, wherein the engagement members each comprise a barbed configuration to engage an interior wall of the atrial appendage.

11. The apparatus defined inclaim 1, wherein the securement means comprises a structure configured to extend distally from the membrane into the ostium and to engage a portion of the interior the left atrial appendage.

12. The apparatus defined inclaim 11, wherein the securement means is configured for enlargement in response to expansion of an expansion structure located in an interior portion of the securement means.

13. The apparatus defined inclaim 11, wherein the securement means is resiliently biased in a enlarged configuration for engagement with the interior wall of the left atrial appendage and may be constrained in a reduced size configuration for installation in the left atrial appendage.

14. The apparatus defined inclaim 1, wherein the membrane has a permeable structure which allows blood to flow through the membrane but substantially inhibits thrombus from passing therethrough.

15. The apparatus defined inclaim 1, wherein the membrane has an impermeable structure which substantially inhibits thrombus and blood from passing therethrough.

16. The apparatus defined inclaim 1, wherein the securement means comprises membrane supporting structure attached to the outer periphery of the membrane and configured to extend radially outward from the ostium to secure the outer periphery of the membrane in direct engagement with the atrial wall surrounding the ostium.

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