Devices for removing fibrin sheaths from catheters
First Claim
1. A medical snare device for removing patient-internal material during a medical procedure comprising:
- an elongate tubular member;
a flexible wire disposed within said tubular member and having a distal end portion which is capable of being extended beyond a terminal end of said tubular member; and
a snare loop attached to said distal end portion of said wire, whereinsaid wire is formed of a shape-memory metal alloy and includes a plurality of axially separated bends to cause said wire to retroflex from a deformed condition wherein said wire is aligned with and confined by said tubular member, and into a non-deformed condition wherein said distal end portion of said wire is flexed in a proximal direction such that the snare loop encircles a distal region of said tubular member in response to extension of said distal end portion of said wire beyond said terminal end of said tubular member.
2 Assignments
0 Petitions
Accused Products
Abstract
Medical devices have a snare loop for removing patient-internal material, for example, a fibrin sheath which may form at the distal end of a venous catheter, and may be inserted intraluminally through the catheter during a medical procedure. The snare loop is capable of retroflexing in a proximal direction when extended beyond the distal end of the catheter so that the snare loop encircles the catheter'"'"'s distal region. Such retroflexing may be accomplished by incorporating at least one pair of bend regions in the guide wire which are axially spaced-apart from one another. These bend regions will cause the shape-memory guide wire to flex upon advancement of the device beyond the distal end of the venous catheter so that the snare loop is capable of retroflexing around the catheter'"'"'s distal end. Alternatively, a number of proximally directed struts having one end attached to the distal end of the guide wire. A draw wire extends from the guide catheter and is flexed in a proximal direction so as to be connected to the snare loop which is positionally held by the terminal ends of the struts. A membrane may optionally be connected to the struts so that the removed fibrin sheath segment may be captured and removed proximally through the lumen of the implanted catheter.
-
Citations
17 Claims
-
1. A medical snare device for removing patient-internal material during a medical procedure comprising:
-
an elongate tubular member; a flexible wire disposed within said tubular member and having a distal end portion which is capable of being extended beyond a terminal end of said tubular member; and a snare loop attached to said distal end portion of said wire, wherein said wire is formed of a shape-memory metal alloy and includes a plurality of axially separated bends to cause said wire to retroflex from a deformed condition wherein said wire is aligned with and confined by said tubular member, and into a non-deformed condition wherein said distal end portion of said wire is flexed in a proximal direction such that the snare loop encircles a distal region of said tubular member in response to extension of said distal end portion of said wire beyond said terminal end of said tubular member. - View Dependent Claims (2, 7, 8, 9)
-
-
3. A medical snare device for removing patient-internal material from a distal end region of a catheter during a medical procedure comprising:
-
an elongate tubular member sized so as to be insertable through the catheter; a flexible wire disposed within said tubular member and having a distal end portion which is capable of being extended beyond a terminal end of said tubular member; a snare loop attached to said distal end portion of said wire; and a number of proximally extending struts each formed of a shape memory alloy and having a distal end attached to said terminal end of said tubular member and a proximal end which includes an eyelet positioned proximally of said terminal end of said tubular member;
whereinsaid flexible wire is threaded through said eyelets of said struts to form said snare loop, and wherein said struts are resiliently moveable from a deformed condition, wherein said struts are aligned with said tubular member, and into a non-deformed condition, wherein said struts extend outwardly so as to expand the snare loop so that relative movement between said tubular member and said catheter causes the snare loop to encircle the distal end region of the catheter. - View Dependent Claims (4, 5)
-
-
6. A medical snare device adapted to being advanced intraluminally through a patient-internal catheter so as to remove biological material at a distal end thereof, said snare device comprising:
-
a elongate tubular member; a flexible wire formed of a shape-memory alloy disposed within said elongate tubular member and having a distal portion thereof formed into a loop; said loop being joined to a remaining proximal section of said flexible wire by at least one bend positioned distally of a terminal end of said elongate tubular member so as to orient said loop within a plane at an angle relative to said elongate tubular member; said flexible wire having at least two other bends formed at axially spaced-apart locations proximally of said terminal end of said tubular member to allow said loop to retroflex proximally over and around the distal end of said patient-internal catheter in response to said loop being extended beyond said terminal end of said tubular member, whereby manipulation of the snare loop removes biological material therefrom.
-
-
10. A medical snare device adapted to being advanced intraluminally through a patient-internal catheter so as to remove biological material at a distal end thereof, said snare device comprising:
-
an elongate tubular member having a terminal end; and a snare assembly disposed at said terminal end of said elongate tubular member, said snare assembly including, (i) at least one pair of flexible wire struts each formed of a shape-memory alloy and having a distal end affixed to said terminal end of said elongate tubular member and an opposite end positioned proximally of said distal end; and (ii) a pull wire intraluminally extending through said tubular member and having a distal section which extends beyond said terminal end of said tubular member, said distal section being flexed proximally and connected to said opposite ends of said wire struts so as to form a snare loop thereat which encircles said tubular member at a location proximally of said catheter distal end and allows said snare loop to be constricted in response to proximal movement of said pull wire within said tubular member, whereby constriction of said snare loop about said distal end of said catheter and distal movement of said snare tubular member relative to said catheter strips said biological material from said catheter distal end. - View Dependent Claims (11, 12, 13)
-
-
14. A procedure for removing a fibrin sheath from a distal end segment of a venous catheter comprising:
-
intraluminally advancing a snare device having a distal snare loop through the venous catheter until said snare loop is positioned distally of said distal end segment of said venous catheter so as to be unconfined thereby; manipulating said snare device to cause said snare loop to retroflexibly encircle said distal end segment of said venous catheter; and
thendistally advancing said snare device while said snare loop thereof is in said encircled relationship with said distal end segment of said venous catheter to cause said snare loop to strip said fibrin sheath therefrom. - View Dependent Claims (15, 16, 17)
-
Specification