Surgery – Means for introducing or removing material from body for... – Treating material introduced into or removed from body...
Reexamination Certificate
1998-10-14
2001-07-03
Nguyen, Anhtuan T. (Department: 3763)
Surgery
Means for introducing or removing material from body for...
Treating material introduced into or removed from body...
C606S194000
Reexamination Certificate
active
06254571
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to embolectomy and thrombectomy devices for manipulating and treating thrombus and clots in the vascular system and, more particularly, to expandable intraluminal catheters for removing occlusive materials from body passages.
2. Description of Related Art
Expanding diameter catheters are commonly used in surgical procedures. A well-known mechanism for expanding the diameter of the catheter is inflation. These balloon-type embolectomy catheters are disclosed in U.S. Pat. No. 3,435,826, U.S. Pat. No. 3,467,101, and U.S. Pat. No. 5,320,604 for use in removing blood clots and thrombus from blood vessels. In addition to balloon-type embolectomy catheters, other mechanisms have been proposed by the prior art in an attempt to improve the procedure of removing clots and thrombus or plaque from blood vessels. U.S. Pat. No. 5,282,484 and U.S. Pat. No. 5,284,486 disclose a catheter having rotating blades. U.S. Pat. No. 5,370,653 discloses a catheter having a brush for removal of material from a blood vessel. U.S. Pat. No. 5,192,290, which is assigned to the assignee of the present invention, discloses a catheter having an expanding elastomeric foam.
All of these prior art embolectomy catheters have intrinsic problems and complications connected with use in delicate blood vessels, regardless of whether balloons, blades, or brushes are used. Since a balloon must be inflated to relatively high pressure in order to ensure proper results, the balloon may rupture or transmit excessive force to the delicate blood vessel. Sclerotic lesions, for example, may occur at sites where the intimal lining of the vessel has been damaged. Blades or brushes can cause extensive damage to the fragile lining of the delicate blood vessel, as well. An elastomeric foam member, such as that disclosed in U.S. Pat. No. 5,192,290, provides a mechanical activation of the expansion means. Although this mechanical activation provides a safety measure by giving the user a tactile feel, the elastomeric foam expansion member does not have the removal capabilities of the above-mentioned balloons, blades, and brushes.
Another problem commonly shared by all of the prior art embolectomy catheters stems from a removal method which is inherently engineered into these devices. A common principle is implemented by each of the prior art devices. Specifically, the expanding members of these prior art devices are advanced beyond the occlusive material to be removed or treated in the blood vessel, and the occlusive material is then forced as a whole along a retrieval path through the blood vessel to a collection site. If the occlusive material is well-attached to the blood vessel wall, the shear forces required to dislodge this material may be damaging to the blood vessel. Since the expanding member basically contacts a perimeter portion of the occlusive material and pushes this material through the vessel to the collection site, a resulting compression of the occlusive material often results. This compression may necessitate the application of additional, excessive force for the removal of the occlusive material, resulting in further damage to the delicate intimal lining of the blood vessel.
SUMMERY OF THE INVENTION
The expansion member of the intraluminal catheter of the present invention harnesses a mechanical activation of the expansion member, and thus does not suffer from the problems associated with prior art balloons, blades, and brushes. This mechanical activation of the expansion member provides the user with a tactile feel. Additionally, the expandable intraluminal catheter of the present invention does not rely on the removal mechanism of the prior art. Specifically, the expandable intraluminal catheter of the present invention does not contact and push only the outer perimeter of the occlusive material in the blood vessel. The expandable intraluminal catheter of this invention contacts the occlusive material along the entire length of the occlusive material within the blood vessel to thereby minimize the compression effect suffered by the prior art. The resulting force required to dislodge or mobilize the occlusive material at any one point within the blood vessel is significantly reduced, since compression is reduced and the mobilizing force is distributed over a large surface area. Since the occlusive material is contacted, and partitioned, at a number of points along the length of the occlusive material within the blood vessel, a risk that the occlusive material may be lost, left behind, or swept into the flow of the blood vessel is also reduced.
The expandable intraluminal catheter of the present invention is able to capture, manipulate, and mobilize thrombus and clots in the vascular system. The expandable intraluminal catheter further provides for the introduction of lysing agents, for example, specifically to, and only to, the affected site. The expandable intraluminal catheter further facilitates aspiration of the lysing agents from the affected site.
The expandable intraluminal catheter is used for removing occlusive material from a body passage. The catheter includes a handle having both a proximal handle end and a distal handle end. Attached to the distal handle end is an elongate tubular body, which includes a proximal body end and a distal body end. The elongate tubular body further includes a lumen between the proximal body end and the distal body end.
A number of expandable segments are disposed on the elongate tubular body near the distal body end. The expandable segments include a proximal expandable segment, a distal expandable segment, and at least one intermediate expandable segment. These expandable segments can be mechanically activated by a user when the distal body end is within a blood vessel to first radially expand the distal expandable segment and the proximal expandable segment. Subsequently, the at least one intermediate expandable segment can be expanded. The expansion of the distal expandable segment and the proximal expandable segment allows the user to isolate the occlusive material, and the subsequent expansion of the at least one intermediate expandable segment allows the user to partition the occlusive material to thereby prepare the occlusive material for removal from the body passage. The isolated and partitioned occlusive material within the body passage can then be removed.
The mechanism for mechanically activating the expandable segments includes a wire disposed within the lumen of the elongate tubular body. A proximal end of the wire is connected to the proximal handle end, and a distal end of the wire is connected to the distal body end. This connection of the wire between the handle and the distal body end fixes the length therebetween. An actuator, connected to the proximal body end, can be actuated by the user to move the proximal body end toward the relatively stationary distal body end. This movement results in an expansion of the expandable segments. Similarly, the user can reverse the direction of the actuator to increase the distance between the proximal body end and the distal body end to thereby decrease the diameters of the expandable segments. The distal expandable segment and the proximal expandable segment, when expanded, have greater diameters than the at least one intermediate expandable segment, when expanded. The greater diameters of the distal expandable segment and the proximal expandable segment allow a user to isolate an occlusive material between the distal expandable segment and the proximal expandable segment, before the at least one intermediate expandable segment is actuated to partition the occlusive material. The isolation of the occlusive material, between the distal expandable segment and the proximal expandable segment, before the partitioning of the occlusive material, substantially prevents portions of the occlusive material from escaping from between the distal expandable segment and the proximal expandable segment and, consequently, allows for a subs
Applied Medical Resources Corporation
Myers, Esq. Richard L.
Nguyen Anhtuan T.
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