Medical balloon folding into predetermined shapes and method

• US 5,456,666 A
• Filed: 04/26/1994
• Issued: 10/10/1995
• Est. Priority Date: 04/26/1994
• Status: Expired due to Term

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Corporation
• Inventors: Campbell, Andrew J., Barry, Ralph J. Jr.
• Primary Examiner(s): YASKO JR, JOHN D
• Application Number:
  US08/233,391
• Time in Patent Office: 532 Days
• Field of Search: 604/96, 604/101, 604/102, 604/103, 606/191-194
• US Class Current: 604/103.08
• CPC Class Codes: A61M 2025/1004 Balloons with folds, e.g. folded or multifolded
• CPC Class Codes: A61M 2025/1031 Surface processing of balloon members, e.g. coating or deposition; Mounting additional parts onto the balloon member's surface
• CPC Class Codes: A61M 25/1029 Production methods of the balloon members, e.g. blow-moulding, extruding, deposition or by wrapping a plurality of layers of balloon material around a mandril
• CPC Class Codes: A61M 25/1038 Wrapping or folding devices for use with balloon catheters
• CPC Class Codes: A61M 29/02 Dilators made of swellable material balloon catheters for angioplasty A61M25/104

Abstract

An inflatable medical balloon (40) at its distal end for introduction into a body part especially through an endoscope (46) and method of making the balloon. When fully inflated, the balloon (40) is a continuous body of balloon material (which may be formed of one or more polymeric layers) with a generally cylindrical shape and four ribs (44) formed in the body. The ribs (44) are longitudinally and equidistantly arranged around an axis (A) which extends from the proximal end to the distal end of the balloon (40). The ribs (44) are formed of stressed balloon material. Webs (45) of less stressed balloon material are disposed between the ribs (44), the ribs and the webs forming the balloon (40) and being expandable from a folded condition for insertion into the body part to an expanded condition with a generally cylindrical shape and a diameter substantially greater than the folded condition whereby to provide medical treatment and, after treatment, being revertible into a folded condition of predetermined configuration with the webs (45) between the ribs (44) collapsing inwardly towards the axis (A). The balloon with its ribs is made by placing an untensioned balloon in a mold (15) having a square cross section with pyramidal end members (3). The mold is heated and balloon is inflated to form ribs (44) of stressed balloon material with webs (45) of less stressed material between them.

Claims

1. A balloon catheter for introduction into a body part through an endoscope, said catheter having a shaft with a proximal and a distal end, said shaft further having at least one lumen and a balloon attached to the distal end of said shaft, said balloon having a proximal and a distal end, said catheter comprising:

a balloon formed of a continuous body of untensioned balloon material and having a generally cylindrical shape;

four ribs disposed in said balloon and being formed of stressed balloon material, said ribs being longitudinally and equidistantly arranged around an axis, said ribs extending as straight lines over the distance between said proximal and distal end of said balloon;

webs of less stressed balloon material disposed between said ribs, said ribs and said webs forming said balloon and being expandable from a folded condition of a predetermined shape for insertion into said body part through said endoscope to an expanded condition with a generally cylindrical shape and a diameter substantially greater than said folded condition by the introduction of inflation fluid through the proximal end of said shaft whereby to provide medical treatment to said part and, after treatment, being revertible into a folded condition with the webs between said ribs collapsing inwardly from the proximal to the distal end of said balloon towards said axis by withdrawal of the inflation fluid without the use of tension to enable said balloon to be withdrawn through said endoscope;

means forming a closure disposed at the distal end of said balloon;

a stiffening wire to stiffen said balloon, said wire extending from said shaft to said closure means and engaging both said shaft and said closure means.

2. The catheter according to claim 1 wherein the stiffening wire is attached to the proximal end of said shaft and the distal end of said balloon.

3. The catheter according to claim 1 wherein the balloon is formed of polyethylene terephthalate.

4. The catheter according to claim 1 wherein the balloon is formed of a base layer of polyethylene terephthalate with a layer of Selar disposed on either side of said base layer.

5. A balloon catheter for introduction into a tubular body conduit, said catheter having a shaft with a proximal and a distal end, said shaft further having at least one lumen and a balloon attached to the distal end of said shaft, said balloon having a proximal and a distal end, said catheter comprising:

a balloon formed of a continuous body of untensioned balloon material and having a generally cylindrical shape;

four ribs disposed in said balloon and being formed of stressed balloon material, said ribs being longitudinally and equidistantly arranged around an axis, said ribs extending as straight lines over the distance between said proximal and distal end of said balloon;

webs of less stressed balloon material disposed between said ribs, said ribs and said webs forming said balloon and being expandable from a folded condition of a predetermined shape for insertion into said body conduit to an expanded condition with a generally cylindrical shape and a diameter substantially greater than said folded condition by the introduction of inflation fluid through the proximal end of said shaft whereby to provide medical treatment within said conduit and, after treatment, being revertible into a folded condition with the webs between said ribs collapsing inwardly from the proximal to the distal end of said balloon towards said axis by withdrawal of the inflation fluid without the use of tension to enable said balloon to be withdrawn from said conduit;

means forming a closure disposed at the distal end of said balloon;

a stiffening wire to stiffen said balloon, said wire extending from said shaft to said closure means and engaging both said shaft and said closure means.

6. The catheter according to claim 5 wherein the stiffening wire is attached to the proximal end of said shaft and the distal end of said balloon.

7. The catheter according to claim 5 wherein the balloon is formed of polyethylene terephthalate.

8. The catheter according to claim 5 wherein the balloon is formed of a base layer of polyethylene terephthalate with a layer of Selar disposed on either side of said base layer.

9. A medical balloon for subsequent attachment to a catheter shaft having a lumen for the introduction of an inflation fluid and subsequent introduction into a body conduit, said balloon being deflatable into a predetermined shape of minimal dimensions, said balloon being formed by the steps comprising:

placing into an elongated mold an untensioned, preformed medical balloon, said balloon having continuous body of balloon material terminating in a tip and having a generally cylindrical shape when inflated, said mold having a length corresponding to the desired length of said balloon and a generally polygonal cross section with side walls of substantially the same width, said side walls being connected by corners, the spacing between opposed corners approximating the desired diameter of the balloon when inflated, said mold further having end members at each end, each of said end members having a pyramidal shape terminating in an apex, said corners of said mold corresponding with the corners of the end members and openings at the apexes to receive the catheter shaft and the tip of the balloon;

heating said mold to the softening point of the balloon and forcing a pressurizing fluid into said balloon to urge said balloon material against the sidewalls and into said corners and into said end members whereby to establish stressed areas where said balloon engages said corners to form four radially arranged ribs with webs disposed therebetween, said ribs extending continuously from the distal to the proximal ends of said balloon, said webs being less stressed than said ribs due to greater expansion distances of said balloon material into said corners than to said sidewalls of said mold, said ribs and said webs forming said balloon and being expandable from a folded condition for insertion into said body conduit to an expanded condition with a diameter substantially greater than its folded condition whereby to provide medical treatment to said conduit and thence, after treatment, into a folded condition with the webs collapsing inwardly towards said axis, said ribs extending parallel to said axis, each of said ribs being radially offset from adjacent ribs by substantially the same distance, whereby to form a balloon with ribs and webs as the body of the balloon, said balloon being expandable to a generally cylindrical shape by the introduction of an expansion fluid and then collapsible upon the withdrawal of said fluid into a structure wherein said webs collapse between said ribs towards said axis to enable easy withdrawal from said body conduit;

opening said mold and removing said balloon from said mold.

10. The balloon according to claim 9 wherein the balloon is heated in the mold to a temperature between about 160°

and 195°

C. and inflated at pressures between about 140 and 200 psi.

11. The balloon according to claim 9 wherein the balloon is formed of polyethylene terephthalate.

12. The balloon according to claim 9 wherein the balloon is formed of a base layer of polyethylene terephthalate with a layer of Selar polymer disposed on at least one side of said base layer.

13. An inflatable medical balloon for introduction into a body conduit, said balloon being deflatable into a predetermined shape of minimal dimensions, said balloon being formed by the steps comprising:

placing an untensioned, preformed medical balloon having continuous body of balloon material with a generally cylindrical shape when inflated in an elongated mold having a length corresponding to the desired length of said balloon and a generally square cross section with four side walls of substantially the same width connected by four corners, said elongated mold further having end members at each end, each of said end members having a pyramidal shape terminating in an apex with the corners of said mold corresponding with the corners of the end members;

heating said mold to the softening point of the balloon and forcing a pressurizing fluid into said balloon to urge said balloon material against the sidewalls and into said corners and into said end members whereby to establish stressed areas where said balloon engages said corners thereby forming four radially arranged ribs with webs therebetween, said ribs extending continuously from the distal to the proximal ends of said balloon, said webs being less stressed than said ribs due to greater expansion distances of said balloon material into said corners then to said sidewalls of said mold, said ribs and said webs constituting said balloon and being expandable from a folded condition for insertion into said body conduit to an expanded condition with a diameter substantially greater than its folded condition whereby to provide medical treatment to said conduit and thence, after treatment, into a folded condition with the webs collapsing inwardly towards said axis, said ribs extending parallel to said axis, each of said ribs being radially offset from adjacent ribs by substantially the same distance, whereby to form a balloon with ribs and webs as the body of the balloon, said balloon being expandable to a generally cylindrical shape by the introduction of an expansion fluid and thence collapsible upon the withdrawal of said fluid into a structure wherein said webs collapse towards said axis to enable easy withdrawal from said body conduit;

removing said balloon from said mold.

14. The balloon according to claim 13 wherein the balloon is heated in the mold to a temperature between about 160°

and 195°

C. and inflated at pressures between about 140 and 200 psi.

15. The catheter according to claim 13 wherein the balloon is formed of polyethylene terephthalate.

16. The catheter according to claim 13 wherein the balloon is formed of a base layer of polyethylene terephthalate with a layer of Selar disposed on either side of said base layer.

17. An inflatable medical balloon for subsequent attachment to a catheter shaft having a lumen for the introduction of an inflation fluid and subsequent introduction into a body conduit, said balloon being deflatable into a predetermined shape of minimal dimensions to be withdrawn from said body conduit, said balloon being formed by the steps comprising:

placing into an elongated mold an untensioned, preformed medical balloon, said balloon having continuous body of balloon material terminating in a tip and having a generally cylindrical shape when inflated, said mold having a length corresponding to the desired length of said balloon and a generally polygonal cross section with side walls of substantially the same width connected by corners, the spacing between opposed corners approximating the desired diameter of the balloon when inflated, said mold further having end members at each end, each of said end members having a pyramidal shape terminating in an apex, said corners of said mold corresponding with the corners of the end members and openings at the apexes to receive the catheter shaft and the tip of the balloon;

heating said mold to the softening point of the balloon and forcing a pressurizing fluid into said balloon to urge said balloon material against the sidewalls, into said corners and said into end members whereby to establish stressed areas where said balloon engages said corners thereby forming four radially arranged ribs with webs therebetween, said ribs extending continuously from the distal to the proximal ends of said balloon, said webs being less stressed than said ribs due to greater expansion distances of said balloon material into said corners than to said sidewalls of said mold, said ribs and said webs forming said balloon and being expandable from a folded condition for insertion into said body conduit to an expanded condition with a diameter substantially greater than its folded condition whereby to provide medical treatment to said conduit and thence, after treatment, into a folded condition with the webs collapsing inwardly towards said axis, said ribs extending parallel to said axis, each of said ribs being radially offset from adjacent ribs by substantially the same distance, whereby to form a balloon with ribs and webs as the body of the balloon, said balloon being expandable to a generally cylindrical shape by the introduction of an expansion fluid and then collapsible upon the withdrawal of said fluid into a structure wherein said webs collapse between said ribs towards said axis to enable easy withdrawal from said body conduit;

opening the mold and removing the balloon from said mold.

18. The balloon according to claim 17 wherein the balloon is heated in the mold to a temperature between about 160°

and 195°

C. and inflated at pressures between about 140 and 200 psi.

19. The balloon according to claim 17 wherein the balloon is formed of polyethylene terephthalate.

20. The balloon according to claim 17 wherein the balloon is formed of a base layer of polyethylene terephthalate with a layer of Selar polymer disposed on at least one side of said base layer.