Method and apparatus for applying vascular grafts

• US 5,366,473 A
• Filed: 08/18/1992
• Issued: 11/22/1994
• Est. Priority Date: 08/18/1992
• Status: Expired due to Term

• Current Assignee: Ultrasonic Sensing and Monitoring Systems Incorporated
• Original Assignee: Ultrasonic Sensing and Monitoring Systems Incorporated
• Inventors: Winston, Thomas R., Neet, John M.
• Primary Examiner(s): BRITTINGHAM, DEBRA
• Application Number:
  US07/931,675
• Time in Patent Office: 826 Days
• Field of Search: 606/191, 606/194, 606/108, 606/198, 623/1, 623/12, 128/20
• US Class Current: 606/198
• CPC Class Codes: A61F 2/07 Stent-grafts
• CPC Class Codes: A61F 2/954 for placing stents or stent-grafts in a bifurcation
• CPC Class Codes: A61F 2/966 with relative longitudinal movement between outer sleeve and prosthesis, e.g. using a push rod
• CPC Class Codes: A61F 2002/065 Y-shaped blood vessels
• CPC Class Codes: A61F 2220/0033 made by longitudinally pushing a protrusion into a complementary-shaped recess, e.g. held by friction fit

Abstract

A vascular graft is held in a collapsed state on a pair of stents which take the form of flexible sheets wound around a spool. A sheath is fitted closely around the graft to hold it in its collapsed state and to retain the stents in rolls tightly wound on the spool. After the spool has been inserted into a damaged vessel and advanced to the area of vascular damage, the sheath is withdrawn. The stents then unwind and expand to press the ends of the graft against healthy parts of the vessel on opposite sides of the damaged area. An alternative embodiment of the invention includes a Y-shaped graft for application to a branched part of a vessel. In place of a sheath, control cords with slip knots are used to retain the stents in their contracted conditions while the graft is being positioned in the vessel. The control cords can be pulled to release the slip knots and permit the stents to expand in a manner to secure two branch portions of the graft in the vessel branches and a trunk portion of the graft in the main trunk of the vessel.

Claims

1. Apparatus for treating a damaged portion of a vessel, comprising:

an elongated core;

a pair of stents on said core at spaced apart locations, each stent comprising a thin flexible sheet tightly wound around the core in a roll having a contracted condition and urged to unwind to an expanded condition,

each of said stent rolls being spirally wound on said core and having a tendency to radially expand, each said roll presenting a plurality of adjacent, arcuate layers of said sheet in a direction transverse to the longitudinal axis of said core;

a flexible graft extending around both stents in a collapsed state and being expansible against the vessel to span the damaged portion thereof, each of said sheets including a tab secured to said graft; and

means for maintaining said rolls in the contracted condition thereof to permit the core to be inserted into the vessel, said maintaining means being selectively releasable to allow said rolls to assume the expanded condition thereof to effect expansion of said graft against the vessel wall,

said rolls in the expanded condition thereof each having at least an inner and an outer layer which overlap and bear against one another over a substantial portion of the circumstance of the inner layer, said expanded rolls securing said graft in said vessel.

2. Apparatus as set forth in claim 1, wherein said maintaining means comprises a sheath sleeved around said graft and movable axially relative to said core to release said stents and allow said rolls to assume the expanded condition.

3. Apparatus for treating a damaged portion of a vessel, comprising:

an elongated core including an elongated stool having an axial passage therethrough for receiving a guide wire to facilitate insertion of the spool into the vessel;

a pair of stents on said core at spaced apart locations, each stent comprising a thin flexible sheet tightly wound around the core in a roll having a contracted condition and urged to unwind to an expanded condition,

each of said stent rolls being spirally wound on said core and having a tendency to radially expand, each said roll presenting a plurality of adjacent, arcuate layers of said sheet in a direction transverse to the longitudinal axis of said core;

a flexible graft extending around both stents in a collapsed state and being expansible against the vessel to span the damaged portion thereof; and

means for maintaining said rolls in the contracted condition thereof to permit the core to be inserted into the vessel, said maintaining means being selectively releasable to allow said rolls to assume the expanded condition thereof to effect expansion of said graft against the vessel wall,

said maintaining means comprising a sheath sleeved around said graft and movable axially relative to said core to release said stents and allow said rolls to assume the expanded condition,

said rolls in the extended condition thereof each having at least an inner and an outer layer which overlap and bear against one another over a substantial portion of the circumference of the inner layer, said expanded rolls securing said graft in said vessel.

4. Apparatus for treating a damaged portion of a vessel, comprising:

an elongated core;

a pair of stents on said core at spaced apart locations, each stent comprising a thin flexible sheet tightly wound around the core in a roll having a contracted condition and urged to unwind to an expanded condition,

each of said stent rolls being spirally wound on said core and having a tendency to radially expand, each said roll presenting a plurality of adjacent, arcuate layers of said sheet in a direction transverse to the longitudinal axis of said core;

a flexible graft extending around both stents in collapsed state and being expansible against the vessel to span the damaged portion thereof; and

means for maintaining said rolls in the contracted condition thereof to permit the core to be inserted into the vessel, said maintaining means being selectively releasable to allow said rolls to assume the expanded condition thereof to effect expansion of said graft against the vessel wall,

said maintaining means comprising a sheath sleeved around said graft and movable axially relative to said core to release said stents and allow said rolls to assume the expanded condition,

said rolls in the expanded condition thereof each having at least an inner and an outer layer which overlap and bear against one another over a substantial portion of the circumference of the inner layer, said expanded rolls securing said graft in said vessel.

5. Apparatus for treating a damaged portion of a vessel at a location thereon where a main trunk of the vessel adjoins first and second branches thereof which cooperate with the main trunk to provide a Y configuration, said apparatus comprising:

a core;

a Y-shaped graft having a trunk portion and first and second branch portions extending from the trunk portion, said graft fitting on said core in a collapsed state and being expansible from the collapsed state to engage said trunk portion against the trunk of the vessel and said first and second branch portions against the respective first and second branches of the vessel;

a first stent on said core within said first branch portion of the graft;

a second stent on said core within said second branch portion of the graft;

a third stent on said core within said trunk portion of the graft, each of said stents comprising a thin flexible sheet arranged in a roll wound around the core in a contracted condition and each of said stents being urged to unwind from the collapsed condition to an expanded condition for pressing the graft against the vessel wall;

spring means for urging first and second branch portions of the graft to spread apart;

means for retaining said first and second branch portions together to allow said core to be inserted into the vessel to the damaged portion thereof, said retaining means being releasable to allow said first and second branch portions to spread apart under the influence of said spring means for entry of said branch portions into the respective first and second branches of the vessel; and

means for maintaining each stent in the contracted condition while the core is being inserted into the vessel, said maintaining means being selectively releasable to permit the stents to assume the expanded condition for holding the first and second branch portions of the graft against the respective first and second branches of the vessel and for holding the trunk portion of the graft against the trunk of the vessel.

6. Apparatus as set forth in claim 5, including a flange on said spool for each stent, said rolls engaging the respective flanges at one end.

7. Apparatus as set forth in claim 6, wherein said maintaining means comprises a control cord for each stent having a slip knot connection with the corresponding flange for holding the corresponding roll in the contracted condition, each slip knot connection releasing the corresponding roll when the control cord is pulled.

8. A method of treating a damaged vessel wall, comprising the steps of:

winding a plurality of flexible metal sheets into rolls carried on a core with each roll being urged to unwind from a contracted condition to an expanded condition;

applying a graft over said rolls with the graft in a collapsed state but being expansible to span the damaged wall with the graft engaging the vessel wall;

inserting said core into the vessel to the damaged wall with the rolls in the contracted condition and the graft in the collapsed state; and

releasing said rolls to allow them to assume the expanded condition and thereby expand the graft and hold it against the vessel wall at a location to span the damaged vessel wall.

9. A method as set forth in claim 8, including the step of sleeving a sheath closely around the graft to hold the rolls in the contracted condition and maintain the graft in the collapsed state while the core is being inserted in the vessel, said releasing step comprising effecting relative axial movement between the sheath and core to displace the sheath from a position confining the rolls and graft.

10. A method as set forth in claim 8, wherein:

the vessel includes a main trunk and a pair of branches extending from the trunk; and

said graft includes a trunk portion for application to the trunk of the vessel and a pair of branch portions for application to the respective branches of the vessel.

11. A method as set forth in claim 10, including the steps of:

holding said branch portions of the graft together while the core is being inserted in the vessel; and

effecting spreading of said branch portions apart to allow them to enter the respective branches of the vessel prior to said releasing step.