Dilatation and stent delivery system and related methods

1. A dilatation and stent delivery system, the system comprising:

a dilatation catheter, the dilatation catheter having an expandable member; and

a stent delivery catheter, the stent delivery catheter comprising:

an inner shaft, the inner shaft comprising a stent retaining region, the inner shaft defining a lumen sized to receive the dilatation catheter and to permit movement of the dilatation catheter relative to the stent delivery catheter,

an outer sheath, the outer sheath having a non-retracted state and a retracted state, the outer sheath comprising a distal end, the distal end of sheath being disposed over the stent retaining region of the inner shaft when the outer sheath is in the non-retracted state, the distal end of the outer sheath being proximal to the stent retaining region when the outer sheath is in the retracted state.

2. The system of claim 1 , wherein the stent delivery catheter includes a locking mechanism at a proximal end for selectively restricting movement of at least a portion of the stent delivery catheter relative to the dilatation catheter.

3. The system of claim 1 , wherein the stent delivery catheter further includes a locking mechanism fixed to a proximal end of the inner shaft for selectively restricting movement of the inner shaft relative to the dilatation catheter.

4. The system of claim 3 , wherein the locking mechanism is configured to selectively engage the dilatation catheter.

5. The system of claim 3 , further comprising a handle at a proximal end of the inner shaft, wherein the locking mechanism is attached to a proximal end of the handle.

6. The system of claim 5 , wherein the inner shaft terminates in the handle, and the locking mechanism defines a lumen to receive the dilatation catheter.

7. The system of claim 3 , the stent delivery catheter further comprising a stent holder configured to retain a stent on the stent retaining region of the inner shaft.

8. The system of claim 3 , further comprising a first handle at a proximal end of the outer sheath and a second handle at the proximal end of the inner shaft.

9. The system of claim 1 , wherein the expandable member is a balloon.

10. The system of claim 9 , wherein the balloon expands to a plurality of distinct diameters corresponding to known inflation pressures.

11. The system of claim 1 , wherein the dilatation catheter defines an inflation lumen for passing inflation fluid to the expandable member and a guide wire lumen for accommodating a guide wire.

12. The system of claim 1 , wherein a length of the dilatation catheter is greater than a length of the stent delivery catheter.

13. The system of claim 1 , wherein the dilatation catheter includes a distal tip a portion of which has a cross-sectional size at least as large as a cross-sectional size of the outer sheath.

14. The system of claim 1 , further comprising a second expandable member at a distal end of the dilatation and stent delivery system.

15. The system of claim 14 , wherein the second expandable member is located on a distal end of the stent delivery catheter.

16. The system of claim 14 , wherein the second expandable member is located on the distal end of the dilatation catheter.

17. The system of claim 14 , wherein the expandable member of the dilatation catheter expands to a first diameter, the second expandable member expands to a second diameter, and the second diameter is larger than the first diameter.

18. The system of claim 1 , wherein the stent delivery catheter further comprises a stent holder configured to retain a stent on the stent retaining region of the inner shaft.

19. The system of claim 1 , further comprising a stent disposed about the stent retaining region of the inner shaft.

20. The system of claim 1 , wherein a distal end of the inner shaft is not fixedly coupled to the outer sheath.

21. The system of claim 1 , wherein the inner shaft is extendable from and retractable into a distal end of the lumen of the outer sheath.

22. The system of claim 21 , wherein the stent delivery catheter further includes a distal tip, the distal tip including a reduced diameter proximal portion for receiving a distal portion of the outer sheath and thereby acting as a seat when the outer sheath is in its distal most position relative to the inner shaft.

23. The system of claim 1 , wherein the expandable member is capable of expanding to a plurality of distinct maximum diameters corresponding to known inflation pressures.

24. The system of claim 1 , wherein the inner shaft is configured to slide along an inner surface of the outer sheath.

25. In combination, a stent and a dilatation and stent delivery system, the combination comprising:

a stent;

a dilatation catheter, the dilatation catheter having a balloon; and

a stent delivery catheter, the stent delivery catheter comprising:

an inner shaft, the inner shaft comprising a stent retaining region, the stent disposed about the stent retaining region; and

a tip, the tip being tubular and engaged to a distal end of the inner shaft; the inner shaft and tip defining a lumen sized to receive the dilatation catheter and permit movement of the dilatation catheter relative to the stent delivery catheter.

26. The combination of claim 25 , wherein the stent is a self-expanding stent.

27. The combination of claim 25 , wherein the stent delivery catheter further comprises a sheath, the sheath having a non-retracted state and a retracted state, the sheath comprising a distal end, the distal end of the sheath being disposed on a proximal end of the tip and over the stent when the sheath is in the non-retracted state, and the distal end of the sheath being proximal to the stent retaining region when the sheath is in the retracted state.