SHEATH WITH CORKSCREW RECAPTURE SYSTEM FOR CATHETER BALLOONS
Publication Date: 2009-Jul-14
The IP.com Prior Art Database
Balloons are incorporated in a number of catheter designs for a variety of purposes. These balloons are typically deployed through a sheath of an insertion device. The balloon exits the sheath and is then inflated. After inflation or use, the balloon is retracted into the sheath a balloon, particularly a large balloon, of a catheter system may have difficulty re-entering the sheath of the insertion device that was used to deliver the balloon. This may be due simply to the amount of balloon material that is to be compressed back into the smaller tube of the sheath. The balloon material may become caught on the sheath wall, preventing full retraction of the balloon into the sheath. This could be risky for a patient as the catheter may be damaged if significant retraction force is applied. For example, the balloon may be dislodged or there may be fluid leakage out of the balloon.
A passive sheath design which facilitates retraction of a catheter balloon into the insertion device includes a corkscrew-rib structure on the inner surface of the sheath. The rib structure acts as a guide path for the balloon to follow, allowing the balloon material to fold and wrap as the catheter is being retracted into the sheath. The spiral rib structure transforms a linear force applied to the proximal end of the catheter into a rotational-linear force on the distal balloon end. A rotational motion applied to the balloon will result in lower retraction forces due to less material hanging up on the sheath wall. The rotational motion should also result in less friction at the balloon to sheath interface. The corkscrew rib structure may be 2-3 inches long on the distal end of the sheath device. The remainder of the sheath can be completely tubular.
The first figure below illustrates a balloon deployed and inflated, prior to retraction into the catheter sheath. Th...