Stent crimping device

SUMMARY

The invention provides a device for crimping heart valve prostheses and a method that is practical, trustworthy and effective, and which seems to fill the need and make progress against existing technology.

According to the invention, a device is provided for reducing the diameter of medical prostheses as defined in the appended claims.

The features, benefits and objects of the invention will become apparent to those skilled in the art by reference to the following description, claims and drawings.

BRIEF DESCRIPTION OF SEVERAL DRAWING VIEWS

The present invention, and the method and process of making and using it, will be better understood by specialists by reference to the following drawings:

Figure 1 is a perspective view of one embodiment of the device for processing tissue prostheses of the present invention.

Figure 2 is also a perspective view of the device.

Figure 3 illustrates embodiments of the reservoir, catheter clamp and device crimping assembly. Figure 4 is an exploded view of the device crimping assembly.

Figure 5 is a perspective view of the crimping assembly.

Figure 6 is a perspective view of the crimping assembly showing an embodiment of the activation ring.

Figure 7 is a perspective view of the rear side of an embodiment of the fixed plate of the crimping assembly.

Figure 8 is a perspective view of the rear side of an embodiment of the main front plate of the crimping assembly.

Figure 9 is an exploded view of an embodiment of the quick-change device catheter clamp.

Figures 10-15 illustrate the process of using the quick change catheter clamp.

Figure 16 is a perspective view of an alternative embodiment of the device crimping assembly.

Figure 17 is a front elevational view of the crimping assembly of Figure 16.

Figure 18 is a flat top view of the same.

Figure 19 end view of the same.

Figure 20A is another perspective view of the crimping assembly, showing the loading element of a fresh set of elements using a loader.

Figure 20B is an exploded view of the crimping assembly.

Figure 21A-B illustrates an embodiment of the crimping assembly activation ring.

Figure 22 is a perspective view of an embodiment of the disposable crimping head of the crimping assembly, also shows the loader.

Figure 23 is an exploded view of the crimping head also showing the loader.

Figure 24 is a perspective view of embodiments of the base and plates of the crimping assembly.

Figure 25 is a front elevational view of the crimping head.

Figure 26 is a perspective view of the embodiment of the crimping element or crimping head segment shown in Figures 4 and 6.

Figure 27 is a perspective view of an alternative embodiment of the crimping element for use with the crimping head shown in Figures 16-25.

Figure 28 is a view showing opposing sides with a dashed line.

Figure 29 is a side view of the segment.

Figure 30 is a view of the longitudinal side of the segment.

Figure 31 is a view of the distal end of the segment.

DETAILED DESCRIPTION

The tissue prosthesis crimping device of the present invention is for use by a single operator for easy diameter reduction or crimping of relatively large stents containing tissue prostheses such as cardiac valves and the like, and places such a device in a catheter for further use and development in a patient. Suitable for "bedside" catheter procedures such as minimally invasive heart valve replacement (MIHVR). The tissue prosthesis crimping device is also for use in comparative tests of medical devices and product testing of such devices on animals.

Referring first to Figures 1-3, a tissue prosthesis crimping device 10 for loading a prosthesis or other medical device (not shown) into a catheter or sheath 11, or other tubular structure, generally includes a crimping assembly 12, immersion tank, or tub 13 for holding a medical solution 14 such as saline and a catheter clamp 15. The device 10 operates during partial immersion in the saline solution 14 which is contained in the extendable tub 13. Tank 13 is most preferably 13 x 7.5 inches, height about 5.25 inches, maximum fluid volume of 5.15 liters with a total weight of about 15 pounds. Only one person is needed to perform any work on the device. The crimping assembly base or frame 19 and catheter clamp 15 are re-usable and can be sterilized with steam and ethylene oxide EtO. All parts in direct contact with the stent or denture, including crimping elements or segments (described below) of the crimping head or assembly 20, are disposable parts that are easy to replace between procedures.

Basically, the operation of the system 10 first requires placing new clamping elements or segments in the crimping head 20 (most preferably with the help of a loader), and moving it to the fully open position. Then, the machine base 19, including the head 20, is placed in the tub 13. The catheter 11 is attached to quickly release the clamp 15. The clamp 15 is attached to the base 19. Then, the prosthesis, paired with the stent, is inserted into the head 20, for example, manually, and the head 20 is actuated, closing its central opening until the individual crimping elements rest against the hard stops. It clamps radially or crimps the stent / denture. The crimped device is pushed (e.g. through a sleeve) or pulled (via an internal device to the catheter) to the catheter 11. This device can be used both with an expandable balloon and with self expandable stents. The clamp on the catheter 15 is removed from the base 19. Finally, the catheter 11 is removed from the clamp 15 with the prosthetic device clamped, for example, a cardiac valve attached therein.

Also referring to Figures 4-6, the crimping assembly 12 comprises a base or frame 19, crimping head 20 and an actuator mechanism 21 connected to the frame and connectable to the crimping head 20. The device also preferably includes a connectable loader 22 for alignment and loading the elements of the crimping head 20 onto the actuator mechanism 21.

Also referring to Figures 7 and 8, the frame 19 includes a base element 25, a front plate 26, a rear plate 27 and side elements 28a and b. The base element 25 provides a lower support for the remaining frame elements 19. Front and rear plates 26 and 27 reach up from the base element 25 and are separated by a certain distance. The front plate 26 has a removable front plate 29. Front plate 29 and rear plate 26 each have a specific arrangement of linear, angled grooves or slots 30 disposed on inwardly facing surfaces surrounding coaxial central holes 35a and b. Each arrangement of grooves 30 preferably has a pair of concentric elements that mate with the elements sliding head members 20 providing linear, radial movement for compression of the stent / prosthesis as described below.

Also referring to Figure 26, the crimping head 20 includes a plurality, e.g., eight (8) crimping segments or elements 34 ah, which are arranged around and define a central opening 35. Each segment 34 has a predefined configuration with an internally narrowed distal end 36, which faces the opening 35 and the outwardly facing proximal end 37. A pair of further rectilinear sliding blocks or arms 38a and b are disposed at the ends of the segment 34 directed along (in terms of the working or entry / exit axis of the device 10 altogether). A pair of proximal slide blocks 39a and b are located nearby. Sliding blocks 38 and 39 are paired with the sliding grooves 30 of plates 26 and 27. Preferably, at least one loader paired with the opening is positioned at each longitudinal end for connecting the loader (not shown). The elements 34 have predetermined substantially flat side sides 41a and b that cooperate with the actuator 21, the sliding blocks 39 and the sliding grooves 30 to move the elements 34. The distal ends are preferably about 50mm in length.

As best shown in Figure 6, the actuator 21 includes an activation ring 43, rollers 47, arms 49, beam 50 and screw 51. Handle 52 is connected to screw 51 for manual rotation by the operator. The bolt 51 is connected through a thread to the end of the beam 50 which is pivotally connected on the pin / hole 53 to the plates 26 and 27. The arms 49a and b are pivotally connected to the beam 50 at one end and to the ring 43 at the other end, through brackets 48a and b. Ring 43 is preferably bifurcated but may have a uniform structure. The ring 43 has a part of the peripheral ring 45 and a plurality of radial spokes 46a - g arranged between the crimping elements 34. The rollers 47a-h are connected to the spokes 46. The rotation of the screw 51 moves the beam 50, which moves the arms 49 and causes them to rotate the activation ring 43 This causes the rollers 47 to contact and move along the side sides 41 of the segments 34. The rotational force of the rollers 47 causes the segments 34 to move linearly along a predetermined path through the grooves 30 as a result of the blocks 39 moving. The distal ends 36 of the segments move towards each other so that the opening 35 becomes smaller and closes. The ends 36 engage and radially compress the prosthetic device disposed in the opening 35.

The preferred maximum diameter of the opening 35 of the crimping head 20 is about 35 mm and may be close to zero mm. Using the teachings of the present invention, the maximum crimping force of the device 10 is about 100 pounds between two opposing elements 34. The maximum number of crimping cycles is about 10 per head 20.

Referring to Figures 9-15, the catheter clamp 15 includes a front plate 68 connected to a lower block 69, an upper block 70 and a spring clamp 71. The catheter 11 is positioned in the central groove or channel of the lower block 69 so that its open end or distal end rests against the front plate 68. As is known in the art, the catheter 11 has an empty lumen. The upper block 70 is positioned above the lower block in such a way that its groove is in line with the catheter 11. Clamp 71 is located above the paired blocks 69 and 70 to hold them in place. The front plate 68 is connectable to the crimping assembly 12 such that the radially compressed, reduced diameter of the prosthesis can be pushed or pulled into the lumen of the catheter 11 through its open end. Clamp 15 will accommodate covers 11 to about 8mm in diameter and about 65mm in length. A reduction of stent diameter of at least 6mm is achieved.

The operation of the device 10 is relatively simple, which minimizes the need for special operator training. The diameter of the final closure depends on the crimping elements 34 selected for the procedure, which essentially minimizes the possibility of operator error during calibration. The crank handle 52 requires minimal physical effort to ensure adequate crimping force. The introduction of a crimped stent can be achieved by two means. The hand-held sleeve can be used to manually push the crimped stent out of the base and into the catheter, or the stent can be pulled out of the base and into the catheter using an internal catheter device. The catheter clamp set 15 accommodates a wide range of French catheter dimensions. The terminals 15 are quickly and easily detached and connected to the base of the device, which reduces the cycle time of the operation and allows easy catheter placement. The clamp design also provides the best alignment of the stent for insertion into the catheter compared to other methods of introducing the stent into the catheter. The insertion opening of the device 10 minimizes the gap between the crimping elements through the whole range of diameters, thus avoiding damage to the stents during compression. The small dimensions and weight of the device 10 allow simple storage and transport.

The modular design of the system 10 also provides several benefits, including the use of disposable items, limited procedure cycle time, limited storage space requirements, and reduced space required for sterilization procedures. Disposable crimping elements 20 eliminate surface contamination between procedures and allow the final closing diameter to be set on future machines. The quick-release catheter clamp 15 allows quick and accurate placement of sheath 11 in clamp 15 and quick connection / disconnection of clamp 15 to base 12. They also prevent base 12 interference with shield loading by allowing operators to load shield 11 while clamp 15 is not connected to base . The spring clamp 71 allows quick release and removal of the upper clamp plate 70 and catheter 11, and serves as a spare handle. In one embodiment, the rotating crank 52 and actuation of the force screw ensure proper holding ability under closed pressure under crimping pressures while requiring little effort from the operator. The linearly moving crimping means 34 reduce the gap between the crimping means 34 when reducing the opening. It also allows for gap elimination all the way through the use of injection-molded parts 34. In addition, this reduces the overall size of the machine 10 as well as the disposable elements 34. The quick replacement of the elements 34 and the element set 20 allows easy transport, sterilization and loading of the disposable element set 20. This avoids damage to the crimping elements 24 during shipment and proper delivery is ensured placing them in the machine base 12. A separate immersion tank 13 reduces the space required for storing the device, allows the machine to be moved in parts, and simplifies watertight protection. The version with adjustable stop allows quick adjustment of the closed diameter for testing purposes. Polymer flat bearings allow steam or ethylene oxide sterilization while reducing pivot friction and eliminating corrosion. Lower adjustable bearing axes allow preloading of bearings from polymer rollers relative to the actuating rings.

Referring to Figures 16-19, an alternative embodiment of the crimping assembly 112 includes a base or frame 119, the crimping head 120 and an actuator mechanism 121 connected to the frame 119 and connectable to the crimping head 120. The device also preferably includes a connectable loader 122 for alignment and loading of the crimping head elements 120 onto the actuator mechanism 121.

Referring to Figures 20 and 24, the frame 119 includes a base element 125, a front frame 126 and a rear frame 127. The base element 125 provides a lower support for the remaining elements of the frame 119. Front and rear plates 126 and 126 extend upward from base element 125 and are separated by a predefined space. Front plate 126 has a detachable front plate 129. Front plate 129 and back plate 126 each have a predetermined array of linear, angled sliding grooves or slots 130 disposed on their inwardly facing surfaces surrounding coaxial central holes 135a and b. The configuration of the groove 130 preferably includes a pair of concentric elements that mate with sliding elements of head 120 to provide linear, radial movement for compression of the stent / prosthesis.

Also referring to Figures 22, 23 and 25, the crimping head 120 includes a plurality, e.g., eight (8) crimping segments or elements 134a-h, which are arranged around and define a central opening 135. As best shown in Figures 27-31, each segment 134 has a predetermined configuration with an inwardly narrowed distal end 136 that faces toward opening 135 and an outwardly facing proximal end 137. A pair of further rectilinear slide blocks or arms 138a and b are disposed at the longitudinally-oriented (in terms of the working or entry / exit axis of the apparatus 10 in general) segment 134. A pair of proximal slide blocks 139a and b are located nearby. Sliding blocks 138 and 139 are paired with sliding grooves 130 for plates 126 and 127. Preferably, at least one loader paired with the opening 171 is disposed at each longitudinal end for connection to the loader 122a and b. Elements 134 have predetermined substantially flat side sides 141a and b of a predefined configuration set on one side that interact with actuator 121, sliding blocks 139 and sliding grooves 130 for moving the elements

134. The distal ends are preferably about 50mm long.

Returning to Figures 20, 21 and 24, the actuator 121 includes an activation ring 143 with an externally profiled gear tooth 144 and numerous activation pin structures 147 inward. The activation ring 143 is held in a rotational position between the plates 126 and 127 by a flat locking gripper ring 145. The handle 152 is connected to the front plate 126 via pin 148 at point 149. The end of the handle has a drive gear 15 that is paired with the profiled gear tooth 144 on the activation ring 143. The rotation of the arm 152 moves the gear 150 that moves the activation ring 143. This causes pin contact 147 and movement along side sides 141 of segments 134.

The rotational force of the pins 147 causes the segments 134 to move linearly along a predetermined path defined by the grooves 130 as a result of the blocks 139 moving. The distal ends 136 of the segments move towards each other, whereby the opening 135 becomes smaller and closes. The ends 136 engage and compress the prosthetic device arranged in the opening 135.

The base 119 also preferably has graphics indicating the loading position of the segment 155, a slot locating the activation ring 156 and an indicator of the position of the loading handle 157 for the convenience of changing the head 120.

"ATENTOWA" BELLEPAT "LAW OFFICE

Izabela Szych niska-Hawranek ul. StOwnCkiedO 44, 37-700 Ρπτ ^ 'ίϊνέΙ tel (016) 742-37-77 fax: (016)&gt; 175-02-87 mobile phone (0608) 503-081 e-maS <a href="mailto:bsliepat@ep.pl">bsliepat@ep.pl</a> NIP: 795-207-16-72 REGON: 1803505 (6

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