| 摘要 |
A multi-sheath delivery catheter and method for introducing a prosthesis into a body lumen involving use of (a) an outer sheath adapted to contain a portion of the prosthesis and having an inner surface with a non-round cross-section; (b) a middle sheath slideably disposed at least partly within the outer sheath and adapted to contain another portion of the prosthesis, the middle sheath having a distal end with a first handle attached to it that has a non-round cross-section corresponding to and engaging the non-round cross-section of the inner surface of the outer sheath; and (c) a pusher slideably disposed at least partly within the middle sheath and adapted to engage the prosthesis, whereby relative rotational movement between the outer sheath and the middle sheath is prevented by virtue of the engagement of the non-round cross-section of the first handle with the non-round cross-section of the inner surface of the outer sheath. In another aspect, the invention provides a delivery catheter having a mechanism for sequentially retracting concentric tubes to deploy the prosthesis. In another aspect, the invention provides a mechanism for preventing relative axial movement of concentric tubes. In another aspect, the invention provides a delivery system for introducing a prosthesis to a body lumen including a nose cone having a hole formed through it that is adapted to communicate with both the interior of the catheter and the ambient environment before insertion of the nose cone into the body lumen, whereby said hole allows flushing of the catheter to remove air bubbles therefrom before insertion into the body lumen. In another aspect, this invention provides a method for preventing leakage of fluid from an interior of a delivery catheter by disposing the outer tube on a mandrel having a cross-sectional area substantially equivalent to that of the inner tube, applying a compressive force to a portion of the outer tube, heating the outer tube to shrink it around the mandrel, and assembling the outer tube concentrically over the inner tube such that a seal is created between the portion of the outer tube and the inner tube.
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