The invention generally relates to a medical device which selectively directs a shaft tip and/or wire guide into a branched body passageway.
Navigating a medical device through a body passage can be difficult when attempting to maneuver within a selected branching pathway, such as a bifurcated duct or vessel. For example, most wire guides lack the ability to maneuver in a particular direction, especially when the direction is against the natural pathway that the wire guide prefers to take.
An example of an area of the body where this poses a problem is the biliary tree, where wire guides are often introduced prior to procedures such as endoscopic retrograde cholangiopancreatography (ERCP), which is a diagnostic visualization technique commonly used with a sphincterotome. The biliary tree includes bifurcations at the junction of the biliary and pancreatic ducts, and between the right and left hepatic ducts. The anatomy of the biliary tree can make navigation of the wire guide into the desired branch of the bifurcation difficult.
Current devices used to direct wire guides have wires attached to the tips of the devices which are tensioned to create a desired tip orientation. Other devices are designed with ramps to deflect the wire guide out of a side port of the device. Both designs suffer drawbacks such as requiring large lumens and offering resistance to wire movement when the device is in a tortuous configuration, such as a branched body passageway.
In view of the difficulties of successfully navigating into and within a branched body passageway, there is a need for a medical device that can reliably gain access to and navigate through a branched body passageway.
The invention may include any of the following aspects in various combinations and may also include any other aspect described below in the written description or in the attached drawings.
In a first aspect, a balloon catheter for use in a body lumen is provided. The balloon catheter comprises a shaft having a distal end and a proximal end. The shaft has one or more inflation lumens in which the one or more inflation lumens proximally extends and terminates into one or more corresponding inflation lumen ports. Each of the corresponding one or more inflation lumen ports is configured to be in fluid communication with a pressurizable inflation source. One or more balloons is disposed circumferentially about the distal end of the shaft. Each of the one or more balloons is disposed along a corresponding portion of a circumference of the distal end of the shaft. Each of the one or more balloons has a separate interior chamber corresponding with the one or more inflation lumens. The one or more balloons has a structure configured for expansion of the interior chamber, such that expansion of the one or more balloons creates an asymmetrical force sufficient to bend the distal end of the shaft in a lateral direction.
In a second aspect, a balloon catheter for use in a body lumen is provided. The balloon catheter comprises a shaft having a distal end and a proximal end. The shaft has a first inflation lumen. The first inflation lumen proximally extends and terminates into a corresponding inflation lumen port. The inflation lumen port is configured to be in fluid communication with a pressurizable inflation source. A first balloon spans a first arc region circumferentially about an outer surface of the distal end of the shaft. The first balloon has a first interior chamber in fluid communication with the first inflation lumen. The first balloon is configured to expand from a deflated state to an expanded state. The expansion creates a first force sufficient to bend the distal end of the shaft in a first lateral direction to produce a first deflection at the distal end along a direction of the first force.
In a third aspect, a method of advancing a device through a tortuous body lumen is provided. A balloon catheter is provided comprising a shaft having a distal end and a proximal end. The shaft has a first inflation lumen. The first inflation lumen proximally extends and terminates into a corresponding first inflation lumen port. The first inflation lumen port is configured to be in fluid communication with a pressurizable inflation source. A first balloon spans a first arc region circumferentially about an outer surface of the distal end of the shaft. The first balloon has a first interior chamber in fluid communication with the first inflation lumen. Inflation fluid is injected through the port with the inflation source to inflate the first balloon. The distal end of the shaft is asymmetrically loaded with a first force. The distal end of the shaft is bent along the direction of the first force in a first direction to create a first bent orientation. Having bent the distal end, the distal end of the shaft is advanced along the first direction to gain access through the body lumen.
The invention may be more fully understood by reading the following description in conjunction with the drawings, in which:
The balloons 111, 121, 131, and 141 may span any circumferential length. In the embodiments shown in
Each of the balloons 111, 121, 131, 141 includes a dedicated inflation lumen 201, 202, 203, and 204 to allow selective expansion of each of the balloons 111, 121, 131, and 141. The interior regions of the balloons 111, 121, 131, and 141 are in fluid communication with corresponding inflation lumens 201, 202, 203, and 204. Inflation fluid may be introduced through one or more of the inflation ports 110, 120, 130, 140 (
The balloon catheter 100 may include a wire guide 230 extending through a wire guide lumen 231, as shown in the Figures.
Still referring to
The degree of bending upon inflation of a single balloon is dependent upon how much inflation fluid is injected into the interior of each of the balloons 111, 121, 131, and 141, as well as the dimensions and the volume capacity of each of the balloons 111, 121, 131, and 141.
Although the embodiments have been described with a balloon catheter 100 having four balloons 111, 121, 131, and 141, more than four or less than four balloons are contemplated. The exact number of balloons may be dependent upon the size of the particular body lumen that the balloon catheter is being navigated and maneuvered within.
Other configurations of the balloons 111, 121, 131, and 141 are contemplated. As one example, the balloons 111, 121, 131, and 141 may be longitudinally staggered along the distal end 171 to create a spiral arrangement. Such a configuration may prevent the distal end of the shaft 171 to be deflected into a spiral orientation.
Additionally, different sized balloons can be placed about the shaft based on the particular application. For example, if relatively greater deflection of the catheter tip is desired to be created to navigate through a tortuous body lumen, then a larger sized balloon may be placed along one of the arc regions 181, 182, 183, and 184 of the shaft 171 outer surface. This may be achieved by either increasing the length and/or diameter of the balloon.
The deflection characteristics of the shaft 171 can also be altered by modifying the manner, location, and size of the attachment between the balloon and the shaft 171 as will now be explained.
The embodiments of
In addition and separate from the above embodiments described in
The shaft 171 may be formed from any biocompatible material. Preferably, the shaft 171 is formed from a compliant material as known in the art that readily undergoes bending when incurring a load. Suitable compliant materials include polyurethane, silicone, latex, polyethylene or polyolefin copolymers. The balloons 111, 121, 131, 141 may be formed from compliant or noncompliant material as known to one of ordinary skill in the art. However, as described with respect to the embodiments of
The shaft 171 may be made by any methods known to one of ordinary skill in the art, including but not limited to extrusion, pultrusion, injection molding, transfer molding, flow encapsulation, fiber winding on a mandrel, or lay-up with vacuum bagging. A variety of suitable materials may be used, so long as the materials provide desired flexibility of the shaft 171. For example, suitable materials include surgical stainless steel or biologically compatible metals, polymers, plastics, alloys (including super-elastic alloys), or composite materials that are either biocompatible or capable of being made biocompatible. Other suitable materials (natural, synthetic, plastic, rubber, metal, or combination thereof) are preferably strong yet flexible and resilient comprising, for by way of illustration and not by way of limitations, elastomeric materials such as and including any latex, silicone, urethane, thermoplastic elastomer, nickel titanium alloy, polyether ether-ketone (“PEEK”), polyimide, polyurethane, cellulose acetate, cellulose nitrate, silicone, polyethylene terephthalate (“PET”), polyamide, polyester, polyorthoester, polyanhydride, polyether sulfone, polycarbonate, polypropylene, high molecular weight polyethylene, polytetrafluoroethylene (“PTFE”), or mixtures or copolymers thereof, polylactic acid, polyglycolic acid or copolymers thereof, polycaprolactone, polyhydroxyalkanoate, polyhydroxy-butyrate valerate, polyhydroxy-butyrate valerate, or another polymer or suitable material.
In one embodiment, the shaft 171 or at least a distal portion therealong may comprise an optional anisotropic material that is, or can be made to be, relatively compliant in an axial direction as compared to a transverse direction. This characteristic is known generally as “anisotropy” (in contrast to “isotropy” where the material characteristics are uniformly independent of direction or orientation within the material). In one embodiment of the invention that uses optional anisotropic material, the specific anisotropic behavior would be achieved by circumferentially reinforcing the shaft 171 so that its “hoop” stiffness (e.g., circumferential stiffness) is higher than its axial stiffness. This could be accomplished by a variety of methods, one of which would be to wrap or wind reinforcing fibers around the shaft 171, or to embed them circumferentially within the material. Consequently, selective inflation of one or more of the balloons 111, 121, 131, and 141 would generate forces within the material of shaft 171 that result in a desired deflection force.
In the axial direction, the specific type of elastic behavior used in formation of shaft 171 may have an impact on the extent to which deflection of shaft 171 along its distal end 170 is created. For example, if an elastomeric material is used (e.g., rubber), which by definition has a distensibility in the range of 200%-800%, then inflation of one or more of the balloons 111, 121, 131, and 141 may generate forces sufficient to generate a relatively large angular deflection, resulting in a sharp (short radius) turn. If a substantially non-elastomeric material is used (e.g., conventional catheter materials) then relatively smaller angular deflections will be created, resulting in a less sharp turn (i.e., large-radius bend). Accordingly, selection of a suitable material may depend, at least in part, on the degree of bending desired when navigating balloon catheter 100 within a particular branched body passageway.
The distal end 170 of shaft 171 may comprise a greater durometer (i.e., harder, more stiff) relative to the proximal portion of shaft 171 so as to enable the distal end 170 to bend but resist kinking during deflection of shaft 171 therealong. Means for achieving the greater durometer include, but are not limited to, affixing an internal or outer reinforcement member to distal end 170, such as a spring, coil, mesh, wire, fiber, or cannula.
A method for maneuvering a balloon catheter 100 within a selected branch of a body passageway will now be described in conjunction with
After the balloon catheter 100 has been advanced through the papilla 450, inflation fluid is introduced into inflation port 120. The fluid may be introduced from any pressurized fluid source. The inflation fluid flows into port 120 (
With balloon 111 remaining in the expanded configuration and the distal end 170 in the desired bent configuration, the wire guide 230 is advanced distally beyond the distal end 170 (
Although the above method has been described using a conventional wire guide as known in the art, the balloon catheter 100 of the present invention may also be used to direct other elongate member members. For example, an elongate fiber having light propagating properties, along its length, such as an optical fiber, may extend through the wire guide lumen 231 of the balloon catheter 100 so as to selectively advance the distal end of the elongate fiber through the biliary duct 430 or pancreatic duct 420. Transmission of light along the optical fiber may further enable the physician to view its advancement into the desired duct 420 or 430.
It should be understood that selected navigation and maneuverability of the catheter 100 within the biliary duct 420 or pancreatic duct 430 are merely exemplary methods and that the balloon catheter 100 may be used to maneuver within other branched body passageways.
The above methods as explained in conjunction with
While preferred embodiments of the invention have been described, it should be understood that the invention is not so limited, and modifications may be made without departing from the invention. The scope of the invention is defined by the appended claims, and all devices that come within the meaning of the claims, either literally or by equivalence, are intended to be embraced therein. Furthermore, the advantages described above are not necessarily the only advantages of the invention, and it is not necessarily expected that all of the described advantages will be achieved with every embodiment of the invention.