Contemporary coronary artery bypass grafting surgery is performed on a beating heart to reduce complications commonly associated with the prior surgical practice of transitioning a patient onto and off of a heart-lung machine. Performing an aortotomy and a proximal anastomisis on an aorta that is perfused with pressurized blood can be facilitated with temporary sealing methods to curtail blood flow through the aortic hole. Side-bite and surface-oriented clamping mechanisms have been used to diminish blood loss during such procedures, but such temporary occlusions can damage the endothelium and dislodge emboli that may migrate through the circulatory system. Alternative schemes for performing an aortotomy and limiting loss of blood include introducing a plug or seal at the site of the aortotomy, but such schemes commonly inhibit convenient and rapid completion of the graft anastomosis.
Resilient, flexible hemostatic seals, or sealing elements, have been developed to temporarily plug the aortic hole while the medical provider grafts a bypass vessel to the hole. Exemplary hemostatic seals are described in U.S. Pat. No. 6,814,743 and in U.S. Patent Application Publication Nos. 2006/0079915 and 2006/0206221. Exemplary commercial seals are those in the HEARTSTRING™ family of proximal seal systems (Boston Scientific; Natick, Mass., U.S.A.).
However, temporary seals like these require the seal portion to be manually folded into a taco-like shape and partially inserted into an introducer before insertion into the aortotomy. Unfortunately, this seal may be easily cracked during manipulation. Moreover, the seal cannot be packaged in a preloaded state into the delivery tool without increasing the risk that the seal will be cracked in transit or before implantation. Thus, a need remains for methods for loading seals into introducers, devices to practices those methods, and systems including the same.
Disclosed herein are methods and devices for folding sealing elements into a configuration that allows placement in an insertion instrument. In one aspect, loading a sealing element into an insertion instrument can include inserting a resilient, flexible sealing element into a loader comprising an elongate body having an inner channel. The proximal end of the elongate body can have an opening sized and shaped to receive the sealing element in an unfolded configuration. Moving the sealing element across at least a portion of the loader, causes the sealing element to fold.
In one embodiment, a loader device and system is disclosed. The system includes a hemostatic sealing element having a flexible body and a loader. The loader can comprise an elongate body extending between a proximal and distal end and having at least one opening sized and shaped for receipt of the hemostatic sealing element in a substantially unfolded configuration. In one aspect, the elongate body further comprising an inner channel that tapers in diameter along at least a portion of the longitudinal length of the channel, wherein the channel is adapted to fold the sealing element when the sealing element is moved through at least a portion of the channel.
In another embodiment, the loader can include an articulating folding feature. The articulating folding feature can be adapted to move between a first position and a second position. When moved from the first to the second position, at least a portion of the articulating folding feature moves relative to the channel and engages the sealing element. In one aspect, the articulating folding feature can apply pressure to the body of the sealing element. For example, the articulating folding feature can push one edge of the sealing element under a second edge of the sealing element to facilitate overlap of the first and second edges.
In one exemplary aspect, the articulating folding feature is a plunger. For example, the plunger can be movably mated with the elongate body. Moving the plunger from the first position to the second position can include moving the plunger transversely with respect to the elongate body. In another aspect, the articulating folding feature is not mated with the elongate body. For example, the loading system can further comprise a stylet for moving through an aperture in the sidewall of the elongate body.
The channel can have a shape configured to facilitate folding of the sealing element. In one aspect, the channel can have a taper. In another aspect, the channel can include a first portion having a constant diameter and second portion having a taper. In yet another aspect, at least a portion of the diameter of the inner channel includes asymmetric radii.
In another embodiment, the loader can be configured to orient the sealing element with respect to the articulating folding feature and/or with respect to an asymmetrically shaped inner surface of the elongate body. In one aspect, the at least one opening for receiving the sealing element can have a shape and size configured to allow ingress of the substantially unfolded sealing element in one orientation and to inhibit entry in a different orientation. For example, the at least one opening can be defined by a keyhole entry.
Another embodiment disclosed herein relates to a loader having diameter that a user can controllably vary. In one such aspect, the loader comprises an at least partially flexible body defining an elongate channel. The wall of the body can include a slit along at least a portion thereof. The body can have at least one opening for receiving a sealing element in a substantially unfolded configuration. A user can place the sealing element into the channel and compress at least a portion of the body to fold the seal. An insertion instrument can then be inserted into the at least one opening and the seal mated with the insertion instrument.
In another embodiment, methods of folding and/or loading the sealing element into an insertion instrument are disclosed. A method can include inserting a resilient, flexible sealing element into a loader comprising an elongate body having a distal end, a proximal end, and at least one opening. The elongate body can further comprise a channel shaped to fold the sealing element. An insertion instrument can be inserted into the at least one opening, the insertion instrument configured to received at least a portion of the sealing element in a folded position. Moving the resilient, flexible sealing element across at least a portion of the channel folds the sealing element. In one aspect, the sealing element is moved by pushing the sealing element through the channel with the insertion instrument.
Additional advantages will be set forth in part in the following description, and in part will be obvious from the description, or may be learned by practice of the invention. The advantages will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive.
Reference will now be made in detail to the present embodiments, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
Disclosed herein are methods, loader devices, and systems useful for loading temporary, hemostatic sealing elements into delivery tools. In turn, these sealing elements may be used to close aortic apertures. These methods, loaders, and systems reduce the risk of cracking the hemostatic seal while loading it into the delivery device.
An unfolded sealing element 70 is depicted in
Sealing element 70 can represent the variety of hemostatic sealing elements. In one exemplary embodiment, sealing element 70 includes a body 72 having a “mushroom” shape with a concave lower surface 74 and a convex upper surface 76. The upper surface of seal body 76 can include a generally circular upper lip with the lower surface curving from the upper lip to a lower point or surface 80. However, one skilled in the art will appreciate that a variety of differently shaped sealing elements, can be used with the loader devices described herein.
Folding of sealing element 70, as illustrated in
Thus, in one aspect, methods for folding sealing element 70 into this folded configuration are disclosed. These methods can include moving the sealing element through a loader to reconfigure the shape of the sealing element. Once folded, the method can include positioning the sealing element, at least partly, in a delivery device. In another aspect, loaders are described for folding the sealing element when the sealing element is moved through a channel defined by at least a portion of the inner surface of the loader. For example, as described below, the loader can have a variety of differently shaped inner surfaces including a tapered inner surface, curved shape, and/or asymmetrical configuration.
In another aspect, exemplary insertion instruments are described, such as insertion instrument 50 illustrated in
Referring now to the pictorial illustrations of
Loader 10 can include, in one aspect, a tapered configuration, the size and shape of which moves edges 78, 78′ toward one another when a seal is moved through channel 26. However, as described below, alternative folding shapes and/or mechanisms can be used with the tapered shape to facilitate overlapping of edges 78, 78′.
In one aspect, at least a portion of the opening at proximal end 19 is defined by a proximal surface 21 that provides a keyhole entry. The keyhole entry includes an aperture having a shape corresponding, at least in part, to a cross-sectional shape of the sealing element in an unfolded configuration. To insert the sealing element, the unfolded sealing element is oriented to match the shape of the keyhole entry. In certain embodiments described below, the keyhole entry can align the sealing element with a non-uniform inner surface of channel 26 and/or with an actuating folding mechanism.
In addition, or alternatively, the keyhole entry can align the insertion instrument with channel 26, or more particularly, can align the insertion instrument with a seal after it has been folded inside channel 26. For example, the keyhole entry can include an aperture with a shape corresponding to a portion of the insertion instrument. Where a folded seal resides on the central longitudinal axis of the loader, the keyhole entry can provide a centrally located opening.
As depicted in
Proximal wall 21 can be integrated into elongate body 14 in one embodiment. In another embodiment, proximal surface wall 21 can be a distinct element that is fixedly or detachably mated with body 14. For example,
Referring to
Once the loader folds, or at least partially folds, seal 70, the seal can then be at least partially loaded into sheath 132 of seal insertion instrument 50 by inserting the distal tip of the sheath into loader 10 and aligning the folded seal with the sheath. To assist with insertion of the seal into the insertion instrument, the loader can include an abutment surface 23 (
In one aspect, the folding feature does not fully fold the sealing element and/or the sealing element is folded (i.e., the sides are overlapped), but the diameter of the sealing element is larger than desired. Moving the sealing element into the sheath will reduce or compress the diameter of the sealing element and mate the sealing element and insertion instrument. Sheath 132 can then be withdrawn from the loader, while retaining the folded sealing element.
The user can also rotate insertion instrument 50 to facilitate loading. In one embodiment, insertion instrument 50 is rotated about one-quarter turn clockwise or counterclockwise. In another embodiment, insertion instrument 50 is rotated about one-half turn clockwise or counterclockwise. In another embodiment, insertion instrument 50 is rotated about a full turn or more clockwise or counterclockwise.
Distal end 18 of loader 10 is depicted illustratively as closed. But the skilled artisan understands that distal end 18 may be open. For example, where the distal end of the loader defines the abutment surface, the distal end of the loader can have an opening sized to prevent passage of the sealing element.
Loader 10 and/or insertion instrument 50 can include a hard stop to limit movement of the insertion instrument into channel 26. For example, where partial insertion of the sealing element into sheath 132 is desired, the insertion instrument can be prevented from insertion into channel 26 more than a predetermined distance. In one aspect, as illustrated in
Referring now to loader 30 depicted in
Sealing element 70 may enter loader 30 at proximal opening 12 and traverse at least a portion of the longitudinal length of loader 30. In one aspect, third diameter D3 is larger than the largest cross-sectional width of an unfolded sealing element. In another aspect, placing the sealing element into the proximal end of channel 26, requires partial folding or bending of the sealing element. For example, the third diameter D3 can be smaller than the largest cross-sectional width of the sealing element, but not small enough to require overlapping of sealing element edges.
As sealing element 70 traverses second portion 34 of loader 70, the decrease in diameter causes the edges of the sealing element to slide up the inside surface of the channel and take a shape corresponding to the inner surface of the channel. A further reduction in diameter cause the sealing element edges to overlap and the seal to fold. The first portion 32 can have a diameter D1 smaller than the maximum outer diameter of a folded sealing element.
In one embodiment, a portion of the insertion instrument and/or channel 26 can provide a hard stop to limit the distance that the folded sealing element is inserted into sheath 132.
In another embodiment, a loader may include an articulating folding mechanism to assist with folding of the sealing element 70. For example, as depicted in
In one aspect, plunger 22 can be spring biased to the second position. Releasing the plunger applies an appropriate and predetermined force on sealing element 70. Alternatively, the plunger can be spring biased in the first position. A user can counteract the force of the spring bias to depress the plunger and move the plunger between the first and second positions.
Plunger 22 can be positioned to contact sealing element 70 closer to an outer edge. Thus, plunger 22 can initiate and/or assist with curling of one of the outer edges toward another, non-adjacent, outer edge. In one aspect, loader 20 includes a keyhole entry to align the sealing element with the location of plunger 22 when the sealing element is positioned in channel 26. The plunger therefore contacts a predetermined area of the sealing element, such as, for example, a portion of the sealing element adjacent to an outer edge.
Plunger 22, as illustrated in
Alternatively, or additionally, plunger 22 as illustrated in
A variety of other articulating folding mechanisms can be used in addition, or as an alternative to the plunger. In one embodiment, the articulating folding mechanism is not mated with elongate body 14. Instead, as illustrated in
In another embodiment of the loader described herein, the loader can have folding features in addition, or as an alternative, to a tapered inner surface. A folding feature 38 is depicted in
The first radius can be sized to direct a first outer edge (e.g., outer edge 78) toward a second, spaced apart edge (e.g., outer edge 78′). The second radius similarly directs the second outer edge toward the first outer edge, but directs the second outer edge along a path such that the second outer edge overlaps the first outer edge. Explained another way, instead of directing outer edges 78, 78′ along corresponding pathways, the difference in the first and second radii facilitates an overlapping fold as the seal 70 moves through the loader 10.
In one aspect, the asymmetric folding feature is formed integrally with the loader. Alternatively, as illustrated in
In another embodiment described herein, instead of the channel having a fixed, tapered diameter along its length, the inner diameter of the loader can be adjustable. As depicted in
Prior to changing the diameter of loader body 64, the loader can have a tapered inner channel similar to the various embodiments of the loader described above. As shown in
In another aspect, changing the inner diameter of the loader can partly fold or bend the sealing element. The insertion instrument 50 can then be introduced into the channel of the loader and used to move the sealing element further into the loader; causing the sealing element to fold. For example, after compressing the loader, the inner channel of the loader retains a tapered configuration and moving the sealing element through a portion of the tapered channel further folds the sealing element.
Alternatively, with respect to
In another embodiment, the loader can be configured to mate with the insertion instrument.
In one aspect, as illustrated in
Once the folded sealing element is mated with the insertion instrument, loader 60 can be detached from the insertion instrument. For example, the loader can be pulled over the folded sealing element. Alternatively, in embodiments where the loader has a slit, a user can expand the slit to allow removal of the loader through the slit. Where the slit does not extend the full length of the loader or where no slit is present, the loader can have a break-away configuration. A user can tear or break the loader away from the insertion instrument.
Another embodiment of a loader is depicted in
In one aspect, as illustrated in
Once folded, or partially folded, the sealing element can enter a portion of the channel where the first and second segments have the same shape. For example, the distal portion 95 of channel 94 can have a circular cross-sectional shape.
In order to align the sealing element such that the first and second segments correspond to different edges of the sealing element, the loader can include an alignment feature. In one aspect, as discussed above with respect to the keyhole entry, the shape of the proximal opening can matches a cross-sectional shape of the sealing element. In another aspect, as shown in
In another embodiment, the housing of the loader can be formed in two or more detachable pieces. The housing can be split or opened to expose at least a portion of channel 94. After folding the sealing element and inserting a portion of a folded sealing element into the insertion instrument, the housing can be opened to allow removal of the insertion instrument and sealing element. Instead of withdrawing the insertion instrument through the channel, the insertion instrument can be lifted out of the channel. In one aspect, this configuration can avoids rubbing the folded sealing element against the walls of the channel, and thereby reduces the risk of inadvertent or premature dislodging of the sealing element from the insertion instrument.
In yet another embodiment, the sealing element and insertion instrument can be inserted in the loader via different entrances.
In one aspect, a user can open loader 120 to expose first area 122 and place a substantially unfolded sealing element therein. Loader 120 can then be closed by bringing body member 114 and 116 together. Opening 124 can have a sized and shape corresponding to a distal portion of an insertion instrument. For example, opening 124 can act align the insertion instrument with the seal positioned within first area 122. A user can direct the insertion instrument through opening 124 and move the sealing element through second area 126. As the sealing element moves through channel 126, loader 120 can fold the sealing element. Once the sealing element is folded, further insertion of the insertion instrument can mate the folded sealing element with the insertion instrument. A user can then removed the mated sealing element and insertion instrument by moving body member 114 away from body member 116 and exposing channel 126.
Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.
This application claims priority to Provisional Application Ser. No. 60/916,006 entitled “Methods And Devices For Loading Temporary Hemostatic Seals” filed May 4, 2007, which is incorporated herein by reference
Number | Date | Country | |
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60916006 | May 2007 | US |