Eye stents and delivery systems and methods
A device for maintaining patency of a channel of an uveolymphatic region or a Schlemm's canal in a patient's eye may include a single elongated element configured for radial expansion of the channel of the uveolymphatic region or the Schlemm's canal when inserted into the channel, wherein the single elongated element is configured to follow an arc of a circumference of the channel, wherein the arc subtends an angle comprising a degree of arc greater than approximately 75 degrees.
1. A method for delivering a stent into Schlemm's canal, the method comprising:
a. detachably coupling a helical single elongated element to a pusher disposed inside a delivery device;
b. advancing the helical single elongated element into a channel of the Schlemm's canal;
c. adjusting the advancement of the helical single elongated element into the channel; and
d. uncoupling the helical single elongated element from the pusher, such that the helical single elongated element is inserted into the channel to radially expand or maintain patency of the channel;
e, wherein the delivery device is configured to block retraction of the helical single elongated element by bracing a proximal end of the helical single elongated element against a distal end of the delivery device such that the helical single elongated element does not retract while retracting the pusher.
2. The method of claim 1 , wherein detachably coupling comprises inserting a full diameter of the pusher into a coil of the helical single elongated element.
3. The method of claim 1 , wherein detachably coupling the helical single elongated element to the pusher comprises detachably coupling by one or more of friction between a tip of the pusher and the helical single elongated element; a retractable suture loop; a mechanical hook, loop, or coil; or an interfacing material configured to provide adherence.
4. The method of claim 1 , wherein adjusting comprises advancing and retracting the helical single elongated element to achieve a predetermined degree of arc of insertion.
5. The method of claim 1 , wherein blocking retraction of the helical single elongated element does not block retraction of the pusher.
6. The method of claim 1 , further comprising withdrawing the pusher and the delivery device from the channel.
7. The method of claim 1 , wherein the pusher is configured to be disposed centrally within the helical single elongated element.
8. The method of claim 1 , wherein the pusher is disposed off-center within the helical single elongated element.
9. The method of claim 1 , wherein advancing the helical single elongated element comprises advancing the helical single elongated element using a fluid and the pusher.
10. The method of claim 9 , wherein the fluid is a viscoelastic fluid.
11. The method of claim 1 , wherein the helical single elongated element is configured to follow an arc of a circumference of the channel, wherein the arc subtends an angle comprising a degree of arc greater than approximately 140 degrees.
12. A system for delivering a stent into Schlemm's canal, the system comprising:
a. at least one helical single elongated element configured to radially expand or maintain patency of a channel of the Schlemm's canal when inserted into the channel; and
b. a pusher detachably coupled to the at least one helical single elongated element and disposed in a delivery device, wherein the pusher is configured to control advancement, retraction, and adjustment of the at least one helical single elongated element in the channel;
c. wherein the delivery device is configured to uncouple the pusher from the at least one helical single elongated element when the at least one helical single elongated element reaches a predetermined location in the channel by bracing a proximal end of the at least one helical single elongated element against a distal end of the delivery device such that the at least one helical single elongated element does not retract while retracting the pusher.
13. The system of claim 12 , wherein the delivery device comprises a cannula.
14. The system of claim 12 , wherein the pusher is configured to be disposed centrally within the at least one helical single elongated element.
15. The system of claim 12 , wherein the pusher is disposed off-center within the at least one helical single elongated element.
16. The system of claim 12 , wherein the pusher and the at least one helical single elongated element are detachably coupled by one or more of friction between a tip of the pusher and the at least one helical single elongated element; a retractable suture loop; a mechanical hook, loop, or coil; or an interfacing material configured to provide adherence.
17. The system of claim 12 , wherein a tip of the pusher is configured to direct the helical single elongated element away from a centerline of the delivery device.
18. The system of claim 12 , wherein one or more of the at least one helical single elongated element, the delivery device, or the pusher comprises a polymeric material selected from a group comprising polyvinylidene fluoride, polyvinylidene difluoride (PVDF), polyvinylpyrrolidone (PVP), polyurethane, polyethylene glycol (PEG), polylactic acid (PLA), polycaprolactone (PCL), polyglycolic acid (PGA), polymethylmethacrylate (PMMA), polyacrylates, polyamide, polyimide, polyesters, silicone, and carbon composites.
19. The system of claim 12 , wherein one or more of the at least one helical single elongated element, the delivery device, or the pusher comprises a metal or metal alloy selected from a group comprising nitinol, titanium, stainless steel, cobalt-chrome alloy, gold, platinum, silver, iridium, tantalum, tungsten, aluminum, and vanadium.
20. The system of claim 12 , wherein the pusher is configured to facilitate advancement of the at least one helical single elongated element into the Schlemm's canal.
21. The system of claim 12 , wherein the at least one helical single elongated element comprises a first helical single elongated element configured to follow a first arc of a circumference of the channel, wherein the arc subtends an angle comprising a degree of arc greater than approximately 140 degrees.
22. The system of claim 21 , wherein the arc subtends an angle comprising a degree of arc greater than approximately 160 degrees.
23. The system of claim 21 , wherein the at least one helical single elongated element further comprises a second helical elongated element separate from the first helical single elongated element, wherein the second helical single elongated element is configured to follow a second arc of the circumference of the channel, and wherein the second arc subtends a second angle comprising a second degree of arc.
24. The system of claim 23 , wherein, when the first and second helical single elongated elements are inserted into the channel of the Schlemm's canal and non-overlapping, the degree of arc of the first arc and the degree of arc of the second arc combined comprise a combined degree of arc between approximately 300 degrees and approximately 360 degrees.
25. The system of claim 12 , further comprising a fluid, wherein the pusher and the fluid are configured to advance the at least one helical single elongated element together.
26. The system of claim 25 , wherein the fluid is a viscoelastic fluid.
27. The system of claim 12 , wherein the at least one helical single elongated element comprises a pre-shaped metal or polymeric filament, wherein the pre-shaped metal filament comprises a shape memory alloy wire.
28. The system of claim 12 , wherein the at least one helical single elongated element is configured to curve along its length when free from constraint to conform to a shape of the channel, wherein the curvature of the at least one helical single elongated element is configured to substantially not exert force on the Schlemm's canal when the at least one helical single elongated element is inserted into the channel.
29. The system of claim 12 , wherein at least one end of the at least one helical single elongated element has a geometry different than that of the remainder of the at least one helical single elongated element.