Apparatus for in-situ cutting of valves within veins and method therefor

• US 5,026,383 A
• Filed: 06/14/1989
• Issued: 06/25/1991
• Est. Priority Date: 06/14/1989
• Status: Expired due to Fees

• Current Assignee: ESC Medical Systems, Ltd (Boston Scientific Corporation)
• Original Assignee: Endovascular, Inc.
• Inventors: Nobles, Anthony A.
• Primary Examiner(s): Hafer, Robert A.
• Assistant Examiner(s): Owens, Kerry
• Application Number:
  US07/366,427
• Time in Patent Office: 741 Days
• Field of Search: 606/159, 606/167, 606/170, 606/179, 606/180, 606/183, 606/194, 604/22
• US Class Current: 606/159
• CPC Class Codes: A61B 17/32075 Pullback cutting; combined forward and pullback cutting, e.g. with cutters at both sides of the plaque
• CPC Class Codes: A61B 2017/22097 Valve removal in veins

Abstract

An apparatus for in-situ cutting through one-way valves in a vein to convert the vein for use as an artery and a method therefor. The apparatus employs a cutting catheter and a pulling catheter. The pulling catheter is advanced through the vein in the normal direction of blood flow and is then connected to a cutting catheter and pulled back reversely through the one-way valves. The cutting catheter carries cutting blades which sever the valve cusps. The connection between the two catheters is effected by a filament which can be swiftly and readily connected to the pulling catheter. The cutting catheter employs a viewing scope which can be utilized to observe the valve cusps and align the cutting blades with the cusps to achieve effective cutting.

Claims

1. An apparatus for the in-situ cutting of valves within a vein when pulled reversely through the vein, the valves having valve cusps extending from diametrically spaced regions attachment to the vein into contact with each other to open and permit flow of blood in a normal direction through the vein but closing together to prevent reverse flow, the apparatus comprising,

a cutting catheter sufficiently flexible to follow the contour of the vein when passed through it, having,

a cylindrical cutting head secured within an open end of said catheter, said cutting head comprising support means having an opening for mounting a viewing scope therein,

a pair of cutting blades secured to one end of said cutting head, said blades having sharp cutting edges and being shaped to engage and cut through the valve cusps when the cutting blades are aligned therewith, said blades having exterior sides which are contoured to generally follow the curvature of the interior walls of the vein, said blades being disposed relative to said opening in said support means to provide an unobstructed space for viewing interior sides of the blades,

a pulling catheter sufficiently flexible to follow the contour of the vein when passed through it,

linkage means for releasably connecting said catheters, said linkage means including,

a filament fixed at one of its ends to said one end of said cutting catheter,

a detent secured to said filament adjacent its other end,

retaining means immovably attached to said pulling catheter for releasably engaging the detent;

and

a viewing scope mounted within the opening in the support means of said cutting catheter to view through the space between said blades, said scope having a field of view of said blades and the adjacent regions within the vein to enable said cutting catheter to be rotated as necessary to align said cutting blades with the valve cusps.

2. An apparatus as defined in claim 1 wherein said cutting catheter and said cutting blades are designed for disposable one-time use, and wherein the support means releasably supports said viewing scope within said cutting catheter, thereby enabling said scope to be removed from said cutting catheter for reuse before said catheter is disposed of.

3. An apparatus as defined in claim 1 wherein,

said detent comprises a ball, and

said retaining means comprises,

a wall fixedly secured to said unbladed catheter having a keyhole shaped slot, said slot having

a head opening adjacent the end of said catheter, and

a slit narrower than said head opening extending longitudinally therefrom, said head opening and said slot being sized to closely

receive said ball and said filament, respectively,

said ball being passed through said head opening and becoming trapped on the opposite side of said wall with said filament extending through said slit to connect said catheters.

4. An apparatus as defined in claim 3 wherein said wall constitutes a tube thereby causing said detent to be housed within the tube interior when said detent is passed through said head opening in said keyhole-shaped slot.

5. An apparatus as defined in claim 4 further having an end wall secured to said tube, said narrow slit extending through said end wall to about the center thereof, said detent pressing against said end wall as the force is applied to the pulling catheter to move said catheters through the vein.

6. An apparatus as defined in claim 1 wherein each said cutting blade has,

an external contour, viewed in a plan direction perpendicular to the major outer surface of the blade, which has a rounded tip extending in a parabola-like shape to blend with the cylindrical outer surface of said cutting head,

an outer edge, viewed side on relative to the plan view, which is flush with the cylindrical outer surface of said cutting head except for a region adjacent the tip which is curved radially inwardly to reduce the risk of gouging the vein in the event of a glancing contact with the vein side wall, and

a cutting edge extending from said tip axially and radially inwardly within said cutting head, said cutting edges of said cutting blades together defining a generally U-shaped opening extending transversely and without obstruction through said cutting head.

7. An apparatus for the in-situ cutting of valves within a vein when moved reversely through the vein, the valves having valve cusps extending from diametrically spaced regions of attachment to vein into contact with each other to open and permit flow of blood in a normal direction through the vein but closing together to prevent reverse flow, the apparatus comprising,

a catheter sufficiently flexible to follow the contour of the vein when passed through it,

a cutting head having,

a generally cylindrical body secured to and extending longitudinally from one end of said catheter,

a pair of cutting blades integral with said body projecting longitudinally and disposed around a periphery of said body to provide a viewing space between the blades, each said cutting blade having sharp cutting edges and comprising,

an external contour, viewed in a plan direction perpendicular to the major outer surface of the blade, which has rounded tip extending in a parabola-like shape to blend with the outer surface of said cylindrical body,

an outer profile, viewed side on relative to the plan view, which is generally flush with the cylindrical outer surface of said body except for a curved radially inwardly curved nose region adjacent the tip to reduce the risk of gouging the vein side wall in the event of a glancing contact with it;

and

a cutting edge extending from said tip axially and radially inwardly from said tip, said cutting edges of said opposed cutting blade defining a generally U-shaped opening having a bell-like flare at its outer end, said cutting edges cutting through the valve cusps when aligned therewith and pulled reversely through the valve; and

a viewing scope mounted within said catheter to view through the viewing space between said blades, said scope having a field of view of said blades and the adjacent regions within the vein to enable said catheter to be rotated as necessary to align said cutting blades with the valve cusps.

8. A method for the in-situ cutting of valves within a vein, the valves having valve cusps extending from diametrically spaced regions of attachment to the vein into contact with each other to provide contacting portions which open to allow blood flow in a normal direction through the vein and which close to prevent reverse flow, the method comprising the steps of,

making entry and exit openings in the vein, with the exit opening spaced downstream of the entry opening in the normal direction of blood flow;

introducing a pulling catheter into the vein through the entry opening and passing the pulling catheter through the vein and valves such that one end of the pulling catheter emerges through the exit opening,

attaching said one end of the pulling catheter to an end of a cutting catheter and applying force to another end of the pulling catheter to move cutting blades on the cutting catheter through the vein to a location proximate to a valve within the vein,

making observations through the viewing scope of the blades in relation to the vein wall and the valves,

positioning nose portions of the blades within respective valve cusps of said valve such that slot portions of the blades receive the contacting portions of the valve cusps, and

applying force to said another end of the pulling catheter to cut the valve.

9. A method as defined in claim 8 wherein the step of attaching comprises,

passing a detent, attached to one of the catheters by a filament, through an opening in a retainer tube on the other of the catheters,

sliding the detent away from the opening towards an end of the tube, said step of sliding the detent comprising sliding the filament through a slot in the tube which is narrower than the detent such that the filament extends from said tube with said detent captured therein.

10. A method, as defined in claim 8, additionally comprising the step of rotating the cutting catheter to position the nose portions of the cutting blades within the valve cusps.

11. An apparatus for the in-situ cutting of a valve within a vein, said valve comprising a pair of valve cusps having portions which contact each other to form a flow path, comprising:

a cutting catheter comprising a cutting head having sharp cutting edges disposed around the periphery of the cutting head to provide a central viewing space between said cutting edges for viewing the interior of said vein, said head comprising a support for mounting a viewing scope to provide viewing through said viewing space, said cutting edges contoured to form a pair of nose regions with a pair of slot regions therebetween, said slot regions sized to receive contacting portions of said valve cusps when said nose regions are inserted into respective valve cusps of said valve; and

a pulling catheter for attaching to said cutting catheter.

12. An apparatus for in-situ cutting of a valve within a vein, comprising:

a cutting catheter comprising a cutting head having cutting edges following a continuous, closed path around a periphery of said cutting head, said cutting edges being substantially equidistant from a central longitudinal axis of said cutting head and forming an open space therebetween, whereby said cutting edges cleanly cut said valve around the entire periphery of said valve without ripping or tearing said valve, said cutting head further comprising a mount for mounting a viewing scope to view said open space; and

a pulling catheter for pulling said cutting catheter through said vein, said cutting edges oriented to cut said valve in response to application of a pulling force on said pulling catheter.