Perfusion catheters and related methods
This patent document discloses perfusion catheters and related methods for treating complications related to CTO interventions or dilating a vessel occlusion while maintaining a passage through the treated vessel segment. A perfusion catheter can include a balloon formed of an inflatable tube and an elongate shaft having a lumen for providing inflation fluid to, or withdrawing inflation fluid from, the balloon. The inflatable tube can be coiled in a helical manner around a central axis into a series of windings. Adjacent windings can be stacked against and bonded to each other, and an inner surface of the series of windings, when inflated, can define the passage. The elongate shaft can be eccentrically attached to a proximal portion of the balloon and the shaft's lumen can be in fluid communication with the interior of the balloon, specifically the inflatable tube. The inflatable tube can include two different polymer tubes, one slightly smaller than the other.
1. A perfusion catheter, comprising:
a balloon including an inflatable tube coiled in a helical manner around a central axis into a
series of windings with adjacent windings stacked against and bonded to each other, an inner surface of the series of windings, when inflated, defining a passage through the center of the helix for delivery of a medical device or maintaining blood flow; an elongate shaft extending proximal of the balloon and eccentrically positioned relative to the passage; and
a guidewire support tube having a length less than a combined length of the balloon and the elongate shaft and having a guidewire lumen therethrough, the guidewire support tube extending through the passage, inset in the interior surface of the series of windings, and non-coaxial with the elongate shaft.
2. The perfusion catheter of claim 1 , wherein the inflatable tube of the balloon includes two different polymer tubes, an inner tube positioned within an outer tube, that are coextruded.
3. The perfusion catheter of claim 2 , wherein the inner tube is formed from a polymer having a radial stiffness to resist collapse or bursting when exposed to inflation pressures, and the outer tube is formed from a polymer configured to exhibit adhesive properties when heated.
4. The perfusion catheter of claim 2 , wherein the inner tube is formed from a polymer that is cross-linked, and the outer tube is formed from a polymer that is non-cross-linked.
5. The perfusion catheter of claim 2 , wherein the inner tube is formed from a polymer having a higher melting temperature than a polymer that forms the outer tube.
6. The perfusion catheter of claim 1 , wherein a proximal portion of the elongate shaft includes a hypotube.
7. The perfusion catheter of claim 6 , wherein a distal portion of the elongate shaft includes a support wire that is coupled to the hypotube.
8. The perfusion catheter of claim 7 , wherein the support wire extends to a location distal to the balloon.
9. The perfusion catheter of claim 1 , wherein a proximal end of the balloon is wrapped about a portion of the elongate shaft.
10. The perfusion catheter of claim 9 , further comprising means to affix the elongate shaft and the proximal end of the balloon, the means to affix creating a fluid tight seal between the elongate shaft and the balloon.
11. The perfusion catheter of claim 10 , wherein the means to affix includes nylon.
12. The perfusion catheter of claim 1 , wherein a polymer of the guidewire support tube and a polymer of the inflatable tube are configured to adhere to each other upon application of heat treatment.
13. The perfusion catheter of claim 1 , wherein the length of the guidewire support tube is longer than a length of the passage.
14. The perfusion catheter of claim 1 , wherein a distal tip of the guidewire support tube includes an atraumatic tip.
15. The perfusion catheter of claim 1 , further comprising a first radiopaque marker positioned proximal to the balloon and a second radiopaque marker positioned distal to the balloon.
16. The perfusion catheter of claim 1 , further comprising a first radiopaque marker positioned on the elongate shaft and a second radiopaque marker position on the guidewire support tube.
17. The perfusion catheter of claim 1 , wherein the passage has a diameter ranging from 2 mm-6 mm and a length ranging from 10 mm-50 mm.
18. The perfusion catheter of claim 1 , wherein the balloon, when inflated, impinges upon or engages a vessel wall at a treatment site at pressures of 2 atm-20 atm.
19. The perfusion catheter of claim 1 , further comprising an elastic sheath disposed around the balloon.