This disclosure relates to surgical apparatus and related methods.
Aortic aneurysms and aortic dissections may occur in the descending aorta (referred to as thoracic or abdominal aneurysms and dissections), in the ascending aorta, or in the transverse arch of the aorta.
One of the features of an aortic dissection is a tear in the intimal layer of the aorta, followed by formation and propagation of a subintimal hematoma (blood clot). The hematoma may occupy a significant percentage, and occasionally all, of the available circumference of the aorta. This also produces a false lumen or double-barreled aorta, which can reduce blood flow to the major arteries arising from the aorta. In the case of the dissection related to the pericardial space, cardiac tamponade other detrimental conditions may result. Aortic aneurysms risk rupture and similar complications.
Aortic aneurysms and dissections currently may be surgically repaired, a procedure which generally requires a surgeon to open the chest cavity, clamp off the aorta, and repair the aneurysm or dissection, such as by sewing a fabric tube, called a graft, to the site. Frequently repair of extensive ascending aortic dissection requires cooling the patient to profound hypothermic level, 18-19 degrees centigrade, in order to allow shutting the blood circulation down; a process called hypothermic circulatory arrest. This enables the surgeon to repair the aortic dissection when it extends into the distal ascending aorta or transverse arch.
It has been proposed to treat thoracic aortic aneurysms by endovascular repair. Such proposals involve insertion of a suitable endoscopic device through the femoral artery, and making a retrograde insertion of an endovascular graft into the descending aorta.
Femoral, retrograde insertion may be contemplated for thoracic aorta aneurysms because of the location of the descending aorta relative to the femoral artery. However, such insertion techniques cannot readily extend into the transverse arch or around the transverse arch and into the ascending aorta.
A stent and/or an aortic valve replacement can be used to treat the aorta. The stent includes a circumferential wall with one portion having apertures defined therein. The apertures permit blood to flow through the circumferential wall at that portion. Another portion of the circumferential wall is configured so that blood substantially does not flow through such portion.
In one variation of the stent, the blood-permeable portion is defined by a bare metal frame with fenestrations therein, and the non-permeable portion is defined by a cover over the frame made of suitable material, such as a non-permeable polymeric material.
The size, configuration, and location of the permeable and non-permeable portions of the circumferential wall may be varied, depending upon the particular application. In one implementation, the stent has permeable, bare metal portions at both of its opposite ends and a covered portion located between these ends. The two bare metal portions and the covered portion are in the form of three, adjacent longitudinal segments. Another possible configuration of the stent includes flanges extending from one of the ends of the stent. The flanges are located and configured to engage the sinuses of valsalva.
Still another possible implementation is to have two longitudinal segments defined on the circumferential wall, one having apertures defined therein, and the other being substantially impermeable to blood flow.
An apparatus for treatment of the aorta includes a suitable delivery system for an endovascular stent, the stent being suitably configured for the particular site in the aorta to be treated. One suitable delivery system is adapted for transapical insertion of the stent. The delivery system includes a transapical valve conduit and a delivery device. One possible implementation of the delivery device includes a delivery tube adapted to carry the stent, and a controller for positioning the stent relative to the aorta. Depending on the application and treatments required, the apparatus may include an outer aortic sheath adapted to be positioned on the outer aortic wall, either in conjunction with the stent, or separately therefrom.
The aortic valve replacement can be used to treat the aorta alone, or in combination with a stent. The aortic valve replacement includes a generally cylindrical member comprising a valve located within the generally cylindrical member and multiple flanges at an end of the generally cylindrical member. The flanges can be configured to be positioned into the sinuses of valsalva.
The aortic valve replacement can be inserted by various methods described herein such as by inserting a delivery device carrying an aortic valve replacement through the apex of the left ventricle, advancing a distal end of the delivery device from the left ventricle into the aorta, and controlling the delivery device to position the aortic valve replacement at a desired location on the inner wall of the aorta. The aortic valve replacement can also be provided to the aorta by providing an aortic valve replacement, the aortic valve replacement comprising a valve and multiple flanges at one of the ends, and positioning the flanges of the aortic valve replacement in the sinuses of valsalva of the aortic valve.
An apparatus for providing an aortic valve replacement, comprises an aortic valve replacement formed of a generally cylindrical member and having a valve located within the generally cylindrical member and multiple flanges at an end of the generally cylindrical member, and a delivery system for transapical insertion of the aortic valve replacement, the system comprising a transapical valve conduit and a delivery device, the delivery device having a delivery tube adapted to carry the aortic valve replacement and a controller for positioning the aortic valve replacement relative to the aorta, the controller including a shaft with a first distal end secured to the aortic valve replacement and second end extending toward the proximal end of the delivery tube.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.
Like reference symbols in the various drawings indicate like elements.
Referring now to the drawings, and in particular to
A second portion 35 of circumferential wall 23 is configured so that blood substantially does not flow through it (blood-impermeable or blood-non-permeable). Portion 35 may be formed of any suitable nonporous material, such as a flexible, polymeric material.
In one possible implementation, circumferential wall 23 is formed by a metal frame 30 having fenestrations defined therein, the frame extending between opposite ends 25 of stent 21. A medial or central portion of the frame carries a cover 26 of polymeric material to define a covered portion 30. The uncovered portions of frame 30, that is, the bare metal portions, include segments 31 and 33. In this implementation, then, proximal bare metal portion 31, intermediate covered portion 35, and distal bare metal portion 33, are adjacent longitudinal segments of lengths A, B, and C, respectively, and located between ends 25 of circumferential wall 23.
Flanges 37 extend from one of the ends 25 of stent 21, in this case, proximal end 27. Although the flanges 37 may assume a variety of forms, in this implementation they are in the form of pods 39 formed from loops of wire. Flanges 37 are located and configured to engage the sinuses of valsalva 41. More particularly, pods 39 extend outwardly from proximal end 27 at spaced locations along the edge of circumferential wall 23, separated by approximately 120° of arc. This configuration permits the outer ends of pods 39 to engage but not obstruct corresponding ones of the three sinuses of valsalva shown in
When seated in the sinuses of valsalva, stent 21 is configured such that bare metal portion 31 spans but does not obstruct the left main and right coronary arteries 43, 45 (
Bare metal portion 33 extends outwardly in the distal direction from covered portion 35. In this implementation, bare metal portion 33 is sized, located, or otherwise configured to span at least one of the arteries 49 extending from transverse arch 51. Arteries 49 include the innominate artery, the left common carotid artery, and the left subclavian artery. It will be appreciated that by configuring stent 21 so that bare metal portions 31 and 33 are in operative proximity to arteries extending from the aorta, the apertures defined in such portions permit blood to flow from the aorta into such arteries.
It will likewise be appreciated that the exact lengths, locations, and even configurations of permeable and impermeable portions on circumferential wall 23 may be varied, customized, or otherwise altered to fit any number of endovascular applications, depending on the configuration of the arteries involved, or the location of the aneurysm or dissection relative to such arteries. Similarly, the overall length of stent 21, as well as the overall length of covered portion 35, may be varied or customized depending on the nature and size of the dissection, aneurysm, or other aortic condition to be treated.
Stent 21 may be delivered to the ascending aorta to be treated by any suitable delivery system through any suitable entry point of the body. Referring now to
As shown in
For example, pods 39 may be pulled back in the proximal direction by members 63 until they have seated in the sinuses of valsalva associated with the aortic valve, as shown in
Although exemplary, transapical surgical methods have been described with reference to stent 21 and delivery system 53, other delivery systems and even other stents may be used transapically, depending on the particular application. Furthermore, stent 21 and alternative implementations of stent 21 are not limited to being delivered transapically. Stent 21 and variations thereof may be inserted through other entry points, by means of other surgical procedures, into other parts of the aorta, other blood vessels, other anatomical systems, and so on.
For certain courses of treatment, it may be desirable for apparatus 19 to include an optional outer aortic sheath 67, one implementation of which is shown in
In certain applications, it may be desirable to use outer aortic sheath 67 in conjunction with an endoaortic stent, such as stent 21. For certain conditions, it may be appropriate for stent 21 and sheath 67 to be positioned on opposite sides of the aorta, such as on opposite sides of the site of the aneurysm or dissection.
A number of implementations of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, it will be appreciated that the size, shape, and location of the blood-permeable and blood-nonpermeable portions of the stent may be varied to account for any number of factors, including the location of the site to be treated, especially in relation to other arteries leading from the aorta, the condition being treated, the location of the dissection, aneurysm, or other treatment site of the blood vessel walls, and the like. In the implementation shown in
Stent 121 shown in
A portion of frame 130 is provided with a cover 126. In this way, stent 121 includes a substantially impermeable longitudinal segment 128 extending over a longitudinal length D, and a blood-permeable segment 140 having length E. In use, stent 121 could be delivered through any suitable endovascular or open surgical procedure and positioned within the blood vessel so that covered, nonpermeable portion 128 is in operative proximity (such as opposing) the area to be treated on the blood vessel wall, whereas bare metal, blood-permeable portion 140 is located in operative proximity to arteries, other blood vessels, valves, ducts, or other openings through which blood or other fluid must flow.
Although the apparatus and associated methods have been discussed with reference to treating the aorta, it will be appreciated that other arteries, blood vessels, and anatomical features may be treated with the stent, the delivery system, or the associated apparatus. It will likewise be appreciated that transapical delivery of the stent is just one way of locating the stent for treatment, and that other insertion techniques and other delivery systems are also suitable.
In some aortic dissections, the dissection can involve the aortic valve and the aortic valve can become incompetent. Furthermore, aortic dilation or failures of the valve itself such as when the annulus loses support can result in the aortic valve becoming incompetent. In these circumstances, the aortic valve can be replaced by an aortic valve replacement.
As shown in
The valve replacement 150 can be inserted into the ascending aorta to be treated by any suitable delivery system through any suitable entry point of the body. For example, the valve replacement 150 can be inserted in the manner illustrated in
As shown in
If the aortic valve replacement 150 is inserted after the stent 21 has already been inserted in the aorta, the aortic valve replacement is guided into the aorta using the procedures described herein. The aortic valve replacement 150 can be designed to snugly fit around the proximal end 27 of the stent 21. The aortic valve replacement 150 can cover a significant portion or the proximal portion A of the stent 21 or substantially all of the proximal portion of the stent such that distal end 158 of the aortic valve replacement covers the proximal portion of the stent. The flanges 152 of the aortic valve replacement 150 can be configured to be substantially collinear with the flanges 37 of the stent 21 as the aortic valve replacement is guided over the proximal portion A of the stent. Once the aortic valve replacement 150 and the stent 21 are engaged, the flanges 152 can be positioned to engage and seat within the sinuses of valsalva as discussed herein. For example, the aortic valve replacement 150 and the stent 21 can be pulled back together toward the aortic valve to position the flanges 152 within the sinuses of valsalva.
As shown in
The outer sheath 67 described herein and illustrated in
Accordingly, other implementations of the apparatus, stents, valve replacements and the delivery systems disclosed herein are within the scope of the following claims.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/US08/54133 | 2/15/2008 | WO | 00 | 10/29/2009 |
| Number | Date | Country | |
|---|---|---|---|
| 60890355 | Feb 2007 | US |