| 摘要 |
A catheter introducer system (10) is provided with a catheter sheath (12) having a valve (90) providing for a friction fit around a catheter. The friction fit is selectively adjustable to vary between a first configuration for longitudinal movement of the catheter through the valve (90) and a second configuration for holding the catheter longitudinally in place. The valve (90) may include a chuck to grip the catheter radially. The chuck may include an annular base (104) and an opposed annular clamp (102), and a washer (92) disposed between the base (104) and the clamp (102). At least one of the base (104) and the clamp (102) may include a beveled surface that forces the washer (92) radially inwardly as the base (104) and the clamp (102) are drawn together. The system also includes one or more dilators layered within the sheath. The layered dilators and sheaths are typically softer and more hydrophilic proceeding from the inner most dilator out to the sheath. The dilator may be reinforced by a wire embedded in the body of the dilator. The distal tip of the sheath may be stiffened by a ring affixed adjacent the distal end. The sheath may include in the innermost dilator a trocar (48) formed of a flexible, hollow outer wire and an inner stiff needle, which can extend beyond the wire for advancement of the dilator. |
