METHODS AND DEVICES FOR TEMPORARILY SEALING A BLOOD VESSEL DURING
AN ANASTOMOSIS
This application is a continuation-in-part of U.S. Provisional Application No. 60/465, 643, filed on April 26, 2003 and is also a continuation-in-part of U.S. Provisional Application No. 60/472,556, filed on May 22, 2003 which are all hereby incorporated by reference.
BACKGROUND OF THE INVENTION
The present invention is directed to methods and devices for temporarily sealing an opening in a body cavity or lumen such as a blood vessel. In particular, the present invention is suited for sealing the opening in the aorta when forming an anastomosis for coronary bypass surgery.
Clamp-type devices are disclosed in U.S. Patent No. 5,447,515 and 6,620,177. A drawback with these clamp-type devices is that a separate incision is required for one arm of the clamp.
Other devices for temporarily sealing an opening in a blood vessel require part of the device to be advanced through the graft lumen. These devices can be problematic when using tissue grafts since the endothelium is relatively delicate and can be easily damaged which may result in an adverse tissue response.
The present invention is directed to additional methods and devices for sealing an opening in a blood vessel.
SUMMARY OF THE INVENTION
The present invention is directed to methods and device for temporarily sealing a body cavity or body lumen such as the aorta. In one aspect of the present invention, a sealing device is provided which has intravascular and extravascular elements magnetically attracted to one another. One or both of the elements may have magnetic components or elements to create the magnetic attraction. The intravascular element has a flexible body which conforms to the shape of the inner wall of the blood vessel. An opening is formed in the blood vessel which is sealed by the intravascular element. The intravascular element may be delivered endovascularly with a catheter, or through a cannula or trocar near the aorta and adjacent to the anastomosis. The device may also be delivered through the same opening that is created to form the anastomosis which provides the benefits described below.
The intravascular element has a flexible body which can deform to the shape of the inner wall of the aorta and, in particular, is flexible to be deformed by magnetic forces exerted by the extravascular element in conformance with the shape of the aorta. In this manner, the extravascular element may be used to deploy and anchor the intravascular element.
In another aspect of the present invention, the intravascular and extravascular elements may be coupled together with a connector extending through the opening used to create the anastomosis. The connector may acts like a spring which clamps the device to the blood vessel. The spring may be created with a wire which acts like a coil spring or with any other suitable structure which provides a spring force. The connector may also simply be a tension element, such as a wire or filament, which is tensioned to create a clamping force between the intravascular and extravascular elements.
These and other features of the invention will become apparent from the following description of the preferred embodiments, drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 shows an intravascular part of a device for temporarily sealing an opening in a blood vessel when creating an anastomosis.
Fig. 2 shows the intravascular component collapsed within a delivery element
Fig. 3 shows the intravascular component with elements advanced into a channel in the device.
Fig. 4 shows a cross-sectional view of the intravascular component.
Fig. 5 shows an extravascular component of the device of Fig. 1.
Fig. 6 shows the device' of Fig. 1 mounted to a blood vessel.
Fig. 7 is an isometric view of another device for temporarily sealing an opening in a blood vessel.
Fig. 8 shows a plan view of the device of Fig. 7.
Fig. 9 shows a side view of the device of Fig. 7.
Fig. 10 shows another device for temporarily sealing an opening in a blood vessel.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is directed to devices and methods for temporarily sealing an opening in a body cavity or lumen such as a blood vessel. In particular, the present invention may be useful for temporarily sealing an opening in the aorta when creating an anastomosis during bypass surgery. It is understood that the descriptions below related to the aorta are equally applicable to use in any body lumen or cavity. Furthermore, the term graft vessel may mean any type of vessel including any biological or synthetic graft including, but not limited to, the internal mammary artery, saphenous vein, foreign tissue grafts and synthetic grafts such as PTFE grafts.
Referring to Figs. 1-5, a device 2 for temporarily sealing an opening in a blood
vessel in accordance with the present invention is shown. The device 2 includes an extravascular component 4 and an intravascular component 6. The components 4, 6 are magnetically attracted to one another to provide a clamping force to temporarily secure the device 2 to the vessel or organ. Either one or both of the components 4, 6 may be magnetic. The extravascular component 6 may be split to facilitate placement and removal. The component 6 may have a number of poles as shown in Fig. 5 or may have fewer poles without departing from the invention. The intravascular component 6 may be delivered through a trocar or cannula 8 near the desired anastomosis site, through a catheter from a peripheral vessel such as the femoral artery, or through the same opening used to form the anastomosis.
Referring to Fig. 2, the intravascular component 6 has a flexible body 14 which is collapsed in a delivery element 15 such as a catheter, cannula or trocar. The component 6 may have one or more elements 10 which are magnetically attracted to the extravascular component 4. The elements 10 may be spherical although any other shape may be used.
The elements 10 may be fixed to the flexible body 14 or may be movable within a channel or lumen 12 in a flexible body 14 so that the device 2 may be more easily collapsed into a relatively small shape. For example, the flexible body 14 may be delivered first followed by advancement of the element 10 into the flexible body when it is desired to expand the intravascular component 6. Removal of the element 10 from the flexible body 14 may facilitate advancement, positioning and removal of the device. This feature may be particularly advantageous when the delivery element 15 is a catheter for endovascular delivery or when the delivery element 15 is delivered through the same opening used to form the anastomosis.
The element 10 is advanced into a channel or pocket 22 in the body. Advancement of the element 10 provides a more defined shape to the intravascular component 6. Even with the element 10 in place, however, the intravascular component 6 is still flexible enough to be deformed by magnetic forces exerted by the extravascular component 4 so that the intravascular component 6 conforms to the shape of the aorta. The element 10 may be advanced into the
flexible body 14 using fluid pressure, a string 17 coupled to the elements 10 or by simply manipulating the element 10 itself. Referring to Fig. 4, the channel or lumen 12 may extend essentially radially from an outer edge of the device or may extend longitudinally from near the middle of the device when the device is introduced through the opening used to create the anastomosis as shown in Fig. 6. Thus, it can be appreciated that a number of different configurations are possible, including many not mentioned here, without departing from the scope of the invention. The flexible body 14 is made of a soft, conformable material, such as silicone, polyurethane or other suitable biocompatible material, to conform to the shape of the vessel. The flexible body 14 may include a thin membrane 20 which seals the opening in the vessel and is surrounded by the channel, lumen or pocket 22.
Use of the device is now described. The intravascular component 6 is advanced to a position adjacent the inner wall of the aorta using the delivery element 15. The component 6 may be delivered with a catheter through a peripheral vessel such as the femoral artery, through a cannula or trocar in the aorta; or directly through the opening used to form the anastomosis as shown in Fig. 6. The component 6 is initially delivered out of the delivery element 15 in a collapsed position. The element(s) 10 are then moved into the channel or lumen 22 in the body 14 to provide a generally circular shape to the component 6. The extravascular component 4 is then moved against the outer wall of the aorta so that the magnetic forces exerted on the intravascular component 6 cause the component 6 to conform to the shape of the aorta and to clamp the aorta between the components 4, 6.
Referring to Figs. 7-9, another sealing device 30 is shown. The sealing device 30 has a membrane 32 which seals against the inner wall of the blood vessel. The device 30 also includes an intravascular part 32 and an extravascular part 34 which contact the inner and outer walls of the blood vessel, respectively. A connector 36 extends between the intravascular and extravascular parts 32, 34. The connector 36 extends through the opening in the blood vessel and provides a spring force which clamps the device 30 to the blood vessel. The device 30 may include a wire 38, such as a superelastic wire, which forms a loop 37 at the intravascular part, a
loop 39 at the extravascular part and length of wire which at the connector 36 which acts like a spring coil.
When the device 30 is mounted to a blood vessel, the intravascular part 32 having the membrane 32 is deflected in direction of arrow 38 so that the connector 36 creates a spring force to clamp the device to the vessel. Two advantages of the device 30 are that no part of the device 30 extends through the lumen of the blood vessel or graft vessel and that the blood vessel and graft vessel are not penetrated or pierced to deliver or mount the device 30. A tear-away member 33, such as a suture, may be used to partially or completely detach the membrane 22 or to simply segment or cut the membrane to facilitate removal.
Referring to Fig. 10, still another sealing device 40 is shown. The device 40 also includes an intravascular part 42 and an extravascular part 44 which contact the inner and outer walls of the blood vessel, respectively. A tensioning element 46 extends through the opening in the vessel which is used to form the anastomosis. The tensioning element 46 is held by the extravascular part 44 and may have a number of discrete positions provided by beads 48. Of course, any other suitable mechanism may be used to apply and maintain tension on the element 46 with or without discrete positions.
The intravascular part 42 as has an expandable frame 50 which opens and closes a cover 52. The frame 50 is collapsed during introduction and removal in any suitable manner as is known in the art. For example, the frame may be collapsed with a ring (not shown) which is simply moved over the frame 50 to collapse the frame 50. Once the intravascular part 42 has been introduced into the blood vessel, the frame 50 is expanded to seal around the opening. Tension is then applied to the tensioning element 46 to form a seal around the opening. The device 40 also shares the same advantages as some of the other devices described herein such as minimal disturbance and trauma to the blood vessel and graft. A suture 54 may be used to tear away part or all of the cover when removing the device. The device 40 is preferably removed directly through the same opening used to create the anastomosis. The extravascular part 34
may be advantageously rotated relative to the intravascular part 32 to so that the device 30 or parts thereof may be moved to reduce interference with creation of the anastomosis.
The present invention has been described in connection with the preferred embodiments but it is understood that the present invention may be practiced using other devices, structures and methods without departing from the scope of the invention.