Abstract
An implant (1) for the treatment of arteriovenous deformities, in particular aneurysms (2). In an expanded state the implant has a basic body (6) comprising of a proximal and a distal segment (7, 8), with the proximal and the distal segment (7, 8) being of dome-shaped configuration, with the convex side of the dome of the proximal segment (7) facing in the proximal direction and the convex side of the dome of the distal segment (8) facing in the distal direction, and wherein the proximal and the distal segment (7, 8) are connected to each other via a plurality of connecting struts (9). Alternatively, the implant (1) may have the shape of a closed tulip blossom. The inventive implant (1) is able to adapt well to the shape of the respective aneurysm (2).
Claims
1. An implant for the treatment aneurysms (2), wherein the implant (1) can be brought in a compressed state through a microcatheter (3) to a target site in the blood vessel system of a patient, with the implant (1) being preset to a secondary structure causing it to assume an expanded state when released from the microcatheter (3), wherein the implant (1) is separably connected to an insertion aid (5) at a detachment point (4), wherein: the implant (1) in the expanded state has a basic body (6) comprising of a proximal and a distal segment (7, 8), with the proximal and the distal segment (7, 8) being of dome-shaped configuration, with the convex side of the dome of the proximal segment (7) facing in the proximal direction and the convex side of the dome of the distal segment (8) facing in the distal direction, and wherein the proximal and the distal segment (7, 8) are connected to each other via a plurality of connecting struts (9).
2. An implant according to claim 1, wherein the configuration of the connecting struts (9) arranged between proximal and distal segments (7, 8) is curvilinear.
3. An implant according to claim 1, wherein the proximal and/or the distal segment (7, 8) are constructed from frame struts (10) which are at least partially connected to each other.
4. An implant according to claim 3, wherein in the expanded state the frame struts (10) form a mesh or loop structure (11) in the proximal and/or distal segment (7, 8).
5. An implant according to claim 3, wherein the distal segment (8) preferably comprises centrally an area (14) free of frame struts (10), said area (14) being expandable and compressible.
6. An implant according to claim 1, wherein the proximal segment (7) is provided with a membrane (12) which covers the proximal segment (7) at least partially.
7. An implant according to claim 6, wherein the distal segment (8) is provided with a membrane (13) which covers the distal segment (8) at least partially.
8. An implant according to claim 6, wherein the connecting struts (9) are at least partially covered with a membrane.
9. An implant for the treatment of aneurysms (2), with the implant (1) being navigable in a compressed state via a microcatheter (3) to a destination in the blood vessel system of a patient, and with the implant (1) being preset to a secondary structure causing it to assume an expanded state when released from the microcatheter (3), with the implant (1) being detachably connected to an insertion aid (5) via a detachment point (4) and, in the expanded state, having a basic body (6) which is composed of struts (16), wherein said struts (16) being at least partially connected to one another at points of intersection, so that interspaces (11) are created between the struts (16), with the struts (16), in the expanded state, extending radially outwards at the proximal end of the basic body (6) and, in the further course, extending axially in the distal direction and radially inwards, so that bulging of the basic body (6) is produced, with the basic body (6) having a zone, at the distal end, where the struts (16) do not have any connection to one another.
10. An implant according to claim 9, wherein the basic body (6) in the expanded state has an opening (14) at the distal end.
11. An implant according to claim 1, wherein the basic body (6) in the expanded state has, by approximation, a spherical shape, an ellipsoidal shape, an ovoid shape, a tulip- blossom shape or the shape of a cylinder with convex outwardly curved base surfaces.
12. An implant according to claim 1, wherein the distal end of the insertion aid (5) is located in the interior of the basic body (6) when the latter is in the expanded state.
13. An implant according to claim 1, wherein the insertion aid (5) is of tubular or hose-shaped design and has an inner lumen.
14. An implant according to claim 13, wherein the tubular or hose-shaped insertion aid (5) projects in distal direction beyond the detachment point (4).
15. An implant according to claim 1, wherein a detachment element (18) is arranged on the outside of the insertion aid (5), said element being connected to the proximal end (23) of the implant (1), wherein by applying an electrical voltage to the detachment element (18) a liberation of the implant (1) can be brought about.
16. An implant according to claim 15, wherein the detachment element (18) is arranged annularly around the insertion aid (5).
17. An implant according to claim 1, wherein the insertion aid (5) has radial protrusions (21) at its distal end on the outside and projects with the distal end into the implant (1) so that a frictional connection between the insertion aid (5), the implant (1) and the microcatheter (3) or a sheath surrounding the distal end of the insertion aid (5) is provided, with the implant (1) being liberated by a movement of the microcatheter (3) or the sheath in the proximal direction relative to the implant (1) and the insertion aid.
18. An implant according to claim 17, wherein the radial protrusions (21) are made of an elastic material.
19. An implant according to claim 13, wherein detachment elements (26) are arranged at the proximal end of the implant (1), said detachment elements engage in a form-closed manner in recesses (27) provided for this purpose in the tubular or hose-shaped insertion aid (5), so that detachment of the implant (1) takes place by movement of the microcatheter (3) or of a sheath surrounding the distal end of the insertion aid (5) in the proximal direction relative to the implant (1) and to the insertion aid (5).
20. An implant according to claim 1, wherein at least one detachment element (31) extends in the proximal direction at the proximal end of the implant (1), said element being secured in a form-closed manner by a retaining element (30) arranged on the insertion aid (5), wherein the retaining element (30) being made of a material having shape memory properties and with the retaining element (30) being preset to a secondary structure, the detachment element (31) being released and detachment of the implant (1) taking place when the secondary structure is assumed, wherein the retaining element (30) is prevented from assuming the secondary structure by the surrounding microcatheter (3) or another sheath surrounding the retaining element (30).
21. An implant according to claim 1, wherein an insertion aid end piece (32) is arranged at the distal end of the insertion aid (5), said end piece having an electrolytically corrodible detachment point (43), wherein the insertion aid end piece (32) is connected in a form-closed manner to an implant end piece (33) arranged at the proximal end of the implant (1), and wherein an insulating element (34) is arranged between the insertion aid end piece (32) and the implant end piece (33) in such a way that direct contact between the insertion aid end piece (32) and the implant end piece (33) is avoided.
22. An implant according to claim 21, wherein the insertion aid end piece (32) and the implant end piece (33) each have a first tubular element (35, 39) and a second tubular element (37, 41), a connecting web (36, 40) is arranged between each the first tubular element (35, 39) and the second tubular element (37, 41), and the second tubular elements (37, 41) each have a radial interruption (38, 42), wherein the insertion aid end piece (32) and the implant end piece (33) are joined together in such a way that the second tubular element (41) of the implant end piece (33) is arranged proximally to the second tubular element (37) of the insertion aid end piece (33).
Description
[0085] Clarification of the invention is provided by the following figures where
[0086] FIG. 1 shows a side view of an inventive implant in an aneurysm according to the first embodiment;
[0087] FIG. 2 shows the inventive implant from FIG. 1 in an X-X view from distal;
[0088] FIG. 3 is a side view of an inventive implant according to the first embodiment of the invention with a detachment point located proximal to the basic body;
[0089] FIG. 4 is a side view of an inventive implant according to the first embodiment of the invention with a detachment point arranged in the interior of the basic body;
[0090] FIG. 5 shows an implant placed in an aneurysm according to the first embodiment with a membrane covering the proximal segment;
[0091] FIG. 6 shows an implant placed in an aneurysm according to the first embodiment with a membrane covering the proximal and the distal segment;
[0092] FIG. 7 shows an implant placed in an aneurysm according to the first embodiment without a membrane, with a detachment point being arranged proximal to the basic body;
[0093] FIG. 8 shows an implant placed in an aneurysm according to the first embodiment without a membrane, with a detachment point being arranged within the basic body;
[0094] FIG. 9 shows an implant placed in an aneurysm according to the first embodiment with a membrane covering the proximal segment and with a detachment point being arranged in the interior of the basic body;
[0095] FIG. 10 shows an implant according to the second embodiment during its release inside the aneurysm;
[0096] FIG. 11 shows the release of the implant illustrated in FIG. 10 at a more advanced stage;
[0097] FIG. 12 depicts an implant according to the second embodiment including a tulip blossom-shaped basic body;
[0098] FIG. 13 shows the insertion of additional occlusion means into the implant illustrated in FIG. 12;
[0099] FIG. 14 shows an electrolytically corrodible detachment point for the severance of the implant;
[0100] FIG. 15 shows another electrolytically corrodible detachment point for the severance of the implant;
[0101] FIG. 16 shows a mechanically releasable, friction-fit based detachment point for release of the implant;
[0102] FIG. 17 is an enlarged view of the mechanically releasable detachment point for the release of the implant shown in FIG. 16;
[0103] FIG. 18 illustrates further examples of mechanically releasable detachment points based on a friction-fit attachment;
[0104] FIG. 19 shows an insertion aid in the form of a flexible tube;
[0105] FIG. 20 shows a mechanically releasable, detachment point on form-closed basis for release of the implant;
[0106] FIG. 21 shows another mechanically releasable, detachment point on form-closed basis for release of the implant;
[0107] FIG. 22 shows an implant with a two-part insertion aid;
[0108] FIG. 23 shows another implant with a two-part insertion aid;
[0109] FIG. 24 is an oblique view of another variant of a detachment point on form-closed basis for detaching the implant in the closed state;
[0110] FIG. 25 is a side view of the detachment point from FIG. 24 in the closed state;
[0111] FIG. 26 is an oblique view of the detachment point from FIG. 24 in the open state;
[0112] FIG. 27 shows a detachment element with a form-fit connection between the insertion aid and the implant, which allows electrolytic release;
[0113] FIG. 28 shows the individual components of the detachment element from FIG. 27;
[0114] FIG. 29 shows different perspectives of the detachment element depicted in FIG. 27;
[0115] FIG. 30 is an exploded view of the interlocking components of the detachment element of FIG. 27 and
[0116] FIG. 31 shows the detachment of the implant using the detachment element illustrated in FIG. 27.
[0117] FIG. 1 is a representation of the invention according to the first embodiment shown as a side view. The Implant 1 has been placed in an aneurysm 2 signified by a dotted line. The implant 1 has a basic body 6, which is composed of a proximal segment 7, a distal segment 8 and connecting struts 9 by means of which the two segments are joined.
[0118] The proximal segment 7 is covered by a membrane 12. Both the proximal segment 7 and the distal segment 8 are made of frame struts 10 that form individual meshes or loops 11. In the proximal segment 7, the frame struts 10 are embedded in the membrane 12. The connecting struts 9 have a curvilinear shape, which ensures that the implant 1 can adapt well, both axially and radially, to the respective conditions of the aneurysm 2. This flexibility is further improved by an area 14 in the distal segment 8 which is free of frame struts 10.
[0119] In the proximal area, the implant 1 is connected to an insertion aid 5 via a detachment point 4, said insertion aid consisting of an insertion wire. The detachment point 4 may, for example, be designed to be detachable electrolytically, which enables the implant 1 to be detached after it has successfully been placed in the aneurysm 2.
[0120] In FIG. 2, implant 1 is shown as seen from the distal side according to the sectional view X-X. The individual loops 11 formed by the frame struts 10 can be seen, which are covered by a membrane 12. Membrane 12 has a blood flow modulating effect and causes the aneurysm 2 to be largely cut off from the flow of blood.
[0121] FIG. 3 is a side view of the first embodiment of the implant 1 proposed by the invention. The implant 1 again has a distal segment 8 and a proximal segment 7, which are connected to each other by connecting struts 9. The connecting struts 9 extend in a curved line. The proximal segment 7 is covered by a membrane 12. Further proximally, implant 1 is connected to the insertion aid 5 via the detachment point 4.
[0122] The illustration in FIG. 4 largely corresponds to that in FIG. 3, but in this case the detachment point 4 is provided inside the basic body 6. This ensures that after detachment of implant 1 no protruding tips of wire are left at the proximal end of implant 1.
[0123] In FIG. 5, implant 1 is shown in fully released state. In the present case, an implant 1 is shown in which the proximal segment 7 is covered by a membrane 12, whereas the distal segment 8 is not covered be a membrane. The detachment point 4 is arranged proximal to basic body 6.
[0124] FIG. 6 shows a corresponding implant 1, which deviates from the implant 1 of FIG. 5 in that the distal segment 8 in this representation also has been provided with a membrane 13. Further covering of the implant 1 with a membrane 13 offers the advantage that an inflow of blood into the aneurysm 2 is largely prevented even in the case of endoleaks.
[0125] FIG. 7 shows a corresponding implant 1 placed in the aneurysm 2 without membranes being provided here. Primarily, an implant 1 of this design serves as a supporting structure to retain occlusion means additionally introduced in the aneurysm 2.
[0126] FIG. 8 largely corresponds to FIG. 7, but unlike in FIG. 7, the detachment point 4 is arranged inside basic body 6. Accordingly, a central invagination/inward curvature of the basic body 6 results so that a protrusion of parts of the implant 1 into the main blood vessel 15 is ruled out.
[0127] In FIG. 9, another implant 1 is illustrated having a detachment point 4 arranged within basic body 6, in which the proximal segment 7 is covered by a membrane 12. The implant 1 thus largely corresponds to that in FIG. 5, but has a different arrangement of the detachment point 4.
[0128] In FIG. 10 a second embodiment of the inventive implant 1 is illustrated, which after expansion assumes the shape of a tulip blossom. The implant 1 is introduced into the aneurysm 2 through a microcatheter 3 via the blood vessel 15 and is liberated by advancing the implant 1 or retracting the microcatheter 3. In the state shown here, only the distal segment 8 of the implant 1 has unfolded, whereas areas of the implant 1 situated further proximal are still in the microcatheter 3.
[0129] In FIG. 11, the liberation of the implant 1 shown in FIG. 10 is in a more advanced stage. The detachment point 4 can be seen, but it is still located inside the microcatheter 3.
[0130] FIG. 12 shows a side view of the implant according to the second embodiment. The implant 1 is composed of partially interconnected struts 16, between which mesh-like interspaces 11 are formed. The implant 1 comprises a plurality of petal-shaped segments 17 that extend from the proximal end of implant 1, first radially outward and slightly in proximal direction, and then further distally and radially inward. In this way, the petal-shaped segments 17 adept closely to and against the inner wall of the aneurysm 2. A central area 14 remains without struts 16 at the distal end of the implant 1, resulting in an opening being created, the size of which may be greater or smaller as required by the size of the aneurysm 2.
[0131] At the proximal end, individual struts 16 of the implant 1 are connected to a detachment element 18 arranged in the form of a ring around the insertion aid 5. The insertion aid 5 is of tubular design and has an inner lumen through which additional occlusion means can be introduced into the implant 1. A release of the implant 1 can be brought about by subjecting the annular detachment element 18 to electrolytic corrosion. In particular, implant 1 can initially be inserted into the aneurysm 2 where it is caused to expand without any release having already occurred at the detachment element 18. Further occlusion means can then be introduced through the insertion aid 5 to fill the interior space of the implant 1. Subsequently, when this process is complete, an electrical current is applied to the ring-shaped detachment element 18 to cause the implant 1 to be liberated. Finally, insertion aid 5 and the microcatheter 3 which is not shown here, are retracted proximally and removed from the blood vessel system.
[0132] FIG. 13 illustrates how through insertion aid 5 additional occlusion means 19 are introduced into the interior space of the implant 1. Implant 1 corresponds to the implant shown in FIG. 12, but is displayed here in a simplified form. By retracting the microcatheter 3, the implant 1 has already been expanded in the aneurysm 2, causing the struts 16 of the implant 1 to be placed in position against the inner wall of aneurysm 2. However, the detachment of implant 1 has not yet occurred.
[0133] The FIGS. 14 and 15 show different ways of detaching implant 1 electrolytically. In both cases, a ring-shaped detachment element 18 is arranged around the tubular insertion aid 5, said element being in connection with the proximal end of the implant 1, which is only hinted at here. An electrical current can be applied to the detachment element 18 via one (FIG. 14) or two (FIG. 15) electrically conductive detachment wires 20, which enables electrolytic corrosion to be initiated, causing detachment and final liberation of the implant 1. Detachment wires 20 are appropriately insulated so that the electric current is applied in a precisely targeted way to the detachment point. Alternatively, the detachment wire 20 may extend through the lumen of the insertion aid 5, or the metal mesh of a catheter-like insertion aid may serve as a suitable conductor.
[0134] In FIGS. 16 and 17 a detachable connection of the implant 1 to the insertion aid 5 is illustrated, which is based on frictional engagement. Radial projections 21 in the form of elastic pads are arranged around the internally hollow insertion aid 5. The proximal end 23 of the implant 1, which in this case comprises individual struts of the implant 1 projecting in proximal direction, has been provided with spherical thickenings 22 and is clamped between the microcatheter 3 and the insertion aid 5. Interaction of the microcatheter 3, the insertion aid 5, the proximal end 23 of the implant 1 and, in particular, the radial protrusions 21 and the thickenings 22 results in a frictional connection being established and rules out premature detachment of implant 1.
[0135] FIG. 17 shows the principle in detail. As soon as microcatheter 3 is retracted in proximal direction (top left in this representation), the proximal end 23 of the implant 1 can expand radially causing the implant 1 to be detached. To enable the treating physician to check the detachment process, radiopaque markers 24 are additionally provided on microcatheter 3.
[0136] FIG. 18a, b, c shows further mechanically separable detachment points based on frictional locking, with a combination of frictional locking and form-closed locking being brought about by appropriate thickenings 22 arranged at the proximal end 23 of implant 1. The thickenings 22 of the proximal end 23 of the implant 1 are arranged either between the radial projections 21 of the insertion aid 5 or vice versa. In each case a microcatheter 3, not shown here, surrounds the arrangement and keeps the proximal end 23 from expanding in radial direction. Accordingly, detachment of implant 1 cannot occur until microcatheter 3 has been retracted in proximal direction.
[0137] In FIG. 19 a tubular insertion aid 5 is shown on which radial protrusions 21 are arranged to bring about the frictional connection. Additionally, various slits 25 are provided in the insertion aid 5 that increase flexibility and facilitate the advancement of the implant 1 through the microcatheter 3, particularly in narrow blood vessels.
[0138] FIG. 20 depicts a form-closed fastening of the proximal end 23 of the implant 1. Form-closed detachment elements 26 are arranged at the proximal end 23, which engage in corresponding recesses 27 in the insertion aid 5. When the microcatheter 3 is retracted in proximal direction, the form-closed detachment elements 26 can expand radially and exit the recesses 27, resulting in the release of the implant 1. To allow the retraction process of the microcatheter 3 to be visualized, the catheter also is provided with radiopaque markers 24.
[0139] Another example of form-closed detachment elements 26 is shown in FIG. 21, with said detachment elements 26 being shaped like segments of a circle and designed to fit into corresponding recesses 27 arranged in the insertion aid 5. When the microcatheter 3 is retracted, the detachment elements 26 can exit the recesses 27, as indicated by the arrows.
[0140] In FIGS. 22 and 23, it is shown that the insertion aid 5 can be composed of two parts. FIGS. 22 and 23 are basically identical, but FIG. 22 shows a form-closed detachment and FIG. 23 shows a frictional detachment as described hereinbefore. The insertion aid 5, which has an inner lumen, is more rigidly formed in the proximal part 28 than in the more flexible distal part 29. For this purpose, the distal part 29 has a helical structure in the form of a two-layer hollow strand that has a high degree of flexibility. In order to be able to transmit torsional forces as well, the turns of the helical structure are opposed to each other.
[0141] FIG. 24 depicts a further variant for fastening the implant 1 to the insertion aid 5 via a form-closed connection, in which at least one detachment element 31 extends in the proximal direction from the proximal end of the implant 1 and is held in a form-closed manner by a retaining element 30 arranged on the insertion aid 5, said retaining element thus engaging around the detachment element 31. The detachment element 31 has a spherical shape. The retaining element 30 is made of a material having shape memory properties. Microcatheter 3, which is not illustrated here, is arranged around the retaining element 30 in the closed state and prevents the latter from assuming an expanded secondary structure and releasing the detachment element 31. FIG. 25 is a side view of the same situation.
[0142] FIG. 26 shows the situation after the microcatheter 3 has been retracted in the proximal direction. The retaining element 30 takes on the preset open secondary structure so that the detaching element 31 can exit which thus causes in the implant 1 to be detached.
[0143] FIG. 27 represents a detachment element 46 based on a combination of mechanical form-closed locking and electrolytic detachability. The detachment element 46 is shown from the front (a), side (b) and rear (c). The detachment element 46 is composed of 3 components, the insertion aid end piece 32, which is located at the distal end of the insertion aid not shown here, the implant end piece 33, which is located at the proximal end of the implant not shown here, and the insulating element 34, which electrically separates the insertion aid end piece 32 and the implant end piece 33 from each other, even when they are in engagement with each other. The insertion aid end piece 32 and the implant end piece 33 overlap, i.e. the distal area of the insertion aid end piece 32 is located distal to the proximal area of the implant end piece 33.
[0144] In FIG. 28, the individual components of the detachment element 46 are shown from the front (a), from the side (b) and from the rear (c). The insertion aid end piece 32 consists of a first short tubular member 35 that is closed radially. This is joined via a connecting web 36 to a second short tubular element 37, which has a radial interruption 38.
[0145] The implant end piece 33 has a virtually identical structure, i.e., it has a radially closed first short tubular element 39, a second short tubular element 41 radially provided with an interruption 42, and a connecting web 40 arranged between the two. However, the position of the insertion aid end piece 32 and the implant end piece 33 is inverted, i.e. the second tubular elements 37 and 41 provided with interruptions 38, 42 face each other, with the interruptions 38, 42 having an offset of 180°.
[0146] The insulating element 34 has a proximal portion 44 and a distal portion 45, and the second tubular element 37 of the insertion aid end piece 32 engages with and surrounds the distal portion 45, whereas the second tubular element 41 of the implant end piece 33 engages with and surrounds the proximal portion 44. In this context, the recesses existing in the proximal and distal sections 44, 45 are in alignment with the second tubular elements 37, 41, i.e., the recesses are completely or largely filled by them. It is achieved in this way that the insertion aid end piece 32 and the implant end piece 33 interlock with each other, but an area of the insulating element 34 is always arranged between the two, so that a voltage applied to the insertion aid end piece 32 is not transmitted to the implant end piece 33, resulting in the two end pieces 32, 33 being insulated from each other.
[0147] Also of importance is the electrolytically corrodible detachment point 43, which dissolves when a current is applied so that separation occurs at this point. The implant is thus released together with the parts of the detachment element 46 that still remain attached, while the proximally located first tubular element 35 of the insertion aid end piece 32 remains on the insertion aid and is retracted in the proximal direction with it. The detachment point 43 is the narrow connection point between the first tubular element 35 and the connecting web 36.
[0148] FIG. 29 shows the interconnected detachment element 46 with insertion aid end piece 32, implant end piece 33 and insulating element 34 from different perspectives. It can be seen how insertion aid end piece 32 and implant end piece 33 are engaged with each other in a form-closed manner, but areas of insulating element 34 always prevent direct contact between insertion aid end piece 32 and implant end piece 33. Furthermore, it can also be seen that a lumen of the detachment element 46 is provided for connection to the lumen of the tubular or hose-shaped insertion aid. Accordingly, this enables additional occlusion means such as coils or embolization agents to be introduced into the aneurysm.
[0149] FIG. 30 is an exploded view of the detachment element 46, from which it can be seen that the second tubular elements 37 and 41 of the insertion end piece 32 and implant end piece 33, which are provided with an interruption, overlap one another, with insulating element 34 being located in between. Both the interruptions 38, 42 in the end pieces 32, 33 and the recesses in the insulating element 34, which are designed to fit to the second tubular elements 37, 41, are radially offset by 180°.
[0150] Finally, FIG. 31 shows the detachment of the implant at the detachment element 46. A current is applied to the detachment point 43 via the insertion aid and the metallic insertion aid end piece 32, with said detachment point 43 being connected as an anode. This arrangement causes the corrodibly designed detachment point 43 to dissolve and the proximal area of the insertion aid end piece 32 disconnects from the other areas of the detachment element 46. The latter are released together with the implant, while the proximal portion of the insertion aid end piece can be retracted in proximal direction and removed from the blood vessel system. The metallic portions of the detachment element 46 remaining on the implant may be made of magnesium, for example, which dissolves over time, causing foreign objects that are no longer needed to disappear. The detachment element 46 ensures a secure form-closed connection between the insertion aid and the implant, which remains in place even if a surrounding microcatheter is retracted proximally resulting in the detachment element 46 to be liberated. Release of the implant does not occur until a voltage is applied to the detachment point 43. Moreover, the form-closed connection between the insertion aid and the implant also allows the transmission of torsional movements.
