METHOD FOR STRAIGHTENING BENT CATHETERS FOR USE

The invention involves a system and method for straightening and refurbishing medical catheters. The system includes the steps and equipment to repair bends and kinks which prevent proper usage of the catheter for a medical procedure. The system and method further checks electrical conductivity and resistance if needed. The catheters are then cleaned and repackaged for shipment and use.

FIELD OF INVENTION

The present invention generally relates to medical catheters; and more particularly, to a method of straightening catheters that have been bent or kinked due to shipping or handling issues during use.

BACKGROUND INFORMATION

In order to reach locations within the human anatomy or vascular system, guide catheters are commonly used. Most guide catheters have proximal and distal ends connected by a long, tubular body having one or more lumens formed therein. The proximal end of the catheter usually includes a handle for control of the catheter by the operator and various ports for introduction of fluids and instruments through the catheter lumen. The distal end includes a tip which is inserted into the patient. For example, in vascular applications, the tip of the catheter can be inserted into a major vein, artery, or other body cavity. The catheter is then further inserted and guided to the area of concern. Moreover, the catheter can also function as a “sheath” or “guide catheter” in that it can be used as a delivery conduit for other tools, such as balloons and/or stents for performing angioplasty, or other instruments mapping electrodes and ablation devices for conducting procedures within the human anatomy.

Current methods for inserting and guiding a catheter include the use of a guide wire, where the guide wire is fed into position within the patient and then the catheter is passed over the guide wire. However, one drawback associated with this method, when the target ablation sites are in or near the pulmonary veins on the posterior surface of the heart, is that it is often difficult, if not impossible, to advance the guide wire all the way to the ultimate target site due to the shape of the heart muscle.

Alternatively, a steerable catheter can be used. Steerable catheters require an ability to selectively deflect the distal tip of the catheter in a desired direction by permitting an operator to adjust the direction of advancement of the distal end of the catheter, as well as to position the distal portion of the catheter. The deflection of the distal tip is typically provided by one or more pull wires that are attached at the distal end of the catheter and extend to a control handle such that the surgeon can selectively deflect the tip and/or rotate the catheter shaft to navigate into the correct position.

When designing such steerable catheters for access into the heart, it is important to have sufficient flexibility in the catheter shaft so that when the catheter is advanced through a blood vessel or heart chamber it can follow the inherent curvature of the biological structures without puncturing them. However, achieving a balance between the “pushability” of the catheter (that is, the ability to direct the tip of the catheter to the target location without buckling or kinking) and the necessary stiffness to allow the catheter to access areas of the anatomy, especially when navigating the sharp turns necessary to access locations in the left atrium of the heart, can be difficult.

More difficulties arise when the catheter includes an ablation instrument having a balloon, as additional maneuvering can be required to properly orient the balloon within or at the mouth of the vein. Further, axial force may be required in order to occlude the pulmonary vein at the ostium, and the lack of stiffness of most catheters renders the application of sufficient force to successfully seal the vein prior to ablation problematic.

These drawbacks often result in bent and/or kinked catheter sheathing. Once bent, the catheter must be replaced, adding significant costs to the surgical procedure. The bent catheters are then typically disposed of.

Therefore, there exists a need in the art to refurbish these bent and/or kinked catheters so that they can be used or re-used to complete surgical procedures. The method of straightening the catheters should be relatively quick and require a minimal amount of tools and hardware. The method and system should not require excessive strength to straighten and check the catheters. Still, the system and method should straighten the catheters in such a way so as not to detract from the aesthetic appearance of the refurbished catheter.

Thus, the present invention provides a method and system for straightening and refurbishing medical catheters which overcomes the disadvantages of prior art. The method and system for straightening catheters of the present invention not only provides for relative ease in the steps and procedures, it also permits a catheter to be used or re-used in surgical procedure.

SUMMARY OF THE INVENTION

Briefly, the invention involves a system and method for straightening and refurbishing medical catheters. The system includes the steps and equipment to repair bends and kinks which prevent proper usage of the catheter for a medical procedure. The system and method further checks electrical conductivity and resistance if needed. The catheters are then cleaned and repackaged for shipment and use.

Accordingly, it is an objective of the present invention to provide a system and method of repairing and/or refurbishing medical catheters.

It is a further objective of the present invention to provide a multi-step system and method for repairing and/or refurbishing medical catheters.

It is yet a further objective of the present invention to provide a series of equipment suitable for use with the method and system for repairing medical catheters.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring generally toFIGS.1-22, a method and system for straightening a bent or kinked medical catheter is illustrated. The system includes a written protocol12for the straightening procedure for each respective catheter. The overview of the method includes parts and documents14, equipment required16, setup and procedure18and inspection20. (FIG.1)FIG.2outlines general precautions22for a particular catheter. In this non-limiting embodiment, the precautions are illustrated for a VNUS catheter (registered trademark) which is typically used to close veins with radio frequency ablation. It should be noted that the present system and method is suitable for use with many other catheters without departing from the scope of the invention. Referring toFIG.3, the process flow chart24is illustrated. The process flow chart24outlines an overview of the steps required to repair the particular medical catheter. These steps may vary from one catheter to another without departing from the scope of the invention. Referring toFIG.4, materials26, equipment28and documents30are specified. In general, the materials26include a list of all the materials needed to repair a bent or kinked medical catheter. The equipment list refers to the equipment required to repair the bends and kinks of a particular medical catheter and the documents section30lists the documents that are needed and/or required for refurbishing a medical catheter, wherein the catheter is intended to be put back into commerce as a usable product or discarded as not usable and tracked for disposal.FIG.5further illustrates the process, including line clearance and documentation review32, set up of the repair34, and physical steps36for modification of the medical catheter. In general, under line clearance32, the person repairing the medical catheter should be trained to modify the medical catheter, and they should sign off on the documents stating that they are trained. The next step under set up34is for the technician to determine whether the medical catheter needs kink or collar repair. Once kink or collar repair is determined, the process12includes a repair reference35that directs the technician to the required steps to complete the required work. In this particular model, the technician is given the choice of kink repair in the collar area of the medical catheter37and kink repair in other portions of the medical catheter38. Under the physical steps section36, the steps for repair of a kink in the collar section of the medical catheter are listed in order of performance. If the medical catheter requires kink repair in an area other than the collar, the technician is directed to kink repair40, shown onFIG.6. This section includes such steps as identifying the kinked area(s), as shown onFIGS.9and10. Once the kinked area is identified, the technician is directed to clean the medical catheter50(FIG.9) with alcohol or a similar film free solvent. The next step requires the technician to place the catheter in a mold44,FIGS.17-22. The mold is generally constructed from a high temperature resistant material such as, but not limited to, ceramic to include an outer diameter42, an inner diameter46, and a length48. The mold44is preferably constructed to include a pair of halves52, which may be held together with clamps54to enclose the outer diameter56of the medical catheter50. Although not required, the mold halves52may include keys, pins, steps or any other alignment device without departing from the scope of the invention. Once the mold44is positioned around the medical catheter50, clamps54may be positioned to hold the mold halves52in position with respect to each other and with respect to the medical catheter50. The mold44and medical catheter50can then be positioned within a device, such as an induction coil58, which is utilized to heat the catheter to a sufficient temperature to either activate the memory of the polymer or reform the polymer to remove the kink. Air may be provided by a blower60to cool the mold and catheter50after being heated. In this manner, the speed of cooling can be controlled, if necessary, to provide the proper material properties for the catheter50. Once the kink(s) in the catheter50are repaired, the mold44can be removed by removing the clamps54.FIG.16illustrates timer and cycle controls for the induction heater used to heat the mold44.

Referring toFIGS.11-16, an alternative or an additional manner of straightening kinks from a catheter50is illustrated. This step includes straightening rolls64. The straightening rolls include a plurality of rollers66arranged in perpendicular planes with respect to each other. Each roller66includes a V-shaped or U-shaped groove68sized to accept and guide the outer diameter of the catheter. In operation, the rollers are set to bend the catheter back and forth in a decreasing manner as it passes over the rollers to cause the catheter to become straight when exiting the straightening rolls64. The catheter50is thus pulled through the straightening rollers66at least one time to remove the kinks. Such straightening rolls are typically used for straightening solid metal wire as it is pulled from a coil for use in manufacturing. After straightening, the solid wire is typically cut to a particular length for use. After straightening the catheter50, any other checks, such as electrical conductivity, resistance and the like may also be completed. Thereafter, the paperwork is completed regarding the inspection of the catheter. The catheter can then be cleaned and repackaged for shipment and use.