Venous access devices (VADs) include ports and indwelling catheters such as peripherally inserted central catheters (PICCs) that include flexible tubes used to supply fluids to internal body structures (e.g., nutrients, medications, blood products, etc.) over extended periods of time. Indwelling catheters may also be used to aspirate fluids such as blood from the patient for diagnostic procedures or to drain fluids for other therapeutic purposes. An indwelling catheter may, for example, include a proximal portion extending outside the skin or inside a pocket under the skin, while a distal tip extends through the body often along a tortuous path to enter a target body structure—e.g., the superior vena cava. To reduce trauma to tissue along this path, indwelling catheters are often made smaller in diameter, resulting in reduced flow rates. Additionally, the implanted portion of the catheter may be susceptible to fibrin sheath adherence and encrustation, which may reduce the mobility of the implanted portion.
The present invention is directed to venous access devices that include branches at the distal end to enhance device flexibility and to minimize the risk of fibrin sheath adherence and encrustation by blood or other bodily fluids.
In one embodiment, the present invention is a venous access device that comprises a catheter portion extending longitudinally from a proximal end to a distal end. The catheter portion includes a first lumen extending in a proximal portion thereof. At its distal end, the device comprises a plurality of branches separated from one another and extending distally from the catheter proximal portion. Each of the plurality of branches includes a lumen that extends between the lumen that extends within the proximal portion of the catheter portion, and a distal end that opens to an exterior of the device.
In another embodiment, the present invention is a venous access device that comprises a multi-lumen catheter portion extending longitudinally from a proximal end to a distal end. The catheter portion includes a plurality of lumens, each extending in a proximal portion thereof. At its distal end, the device divides into sections, with each section containing at least one of the plurality of lumens, and each section further comprising a plurality of branches separated from one another and extending distally therefrom. Each of the plurality of branches includes a lumen that extends between the lumen(s) that extends within each section and a distal end that opens to an exterior of the device.
The present invention may be further understood with reference to the following description and the appended drawings, wherein like elements are referred to with the same reference numerals. The present invention relates to devices for the transfer of fluids to and from a target structure within a patient's body over an extended period of time. In particular, exemplary embodiments of the present invention describe a venous access device that includes a branched distal tip for improved mobility, flexibility and flow.
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The inventors have found that the use of branches 112 enhance the mobility and flexibility of the indwelling portion of the catheter portion 102 as compared to a single tube catheter. For example, in embodiments where the outer diameter of each of the branches 112 is smaller than the outer diameter of the proximal portion 118, it will be understood by those of skill in the art that the distal end 110 of the device is more flexible than the proximal portion 118. This enhanced flexibility allows for greater movement of the device 100 at its distal end 110 while implanted, such as with normal cardiovascular flow and pulse. The added flexibility and motion of the branches 112 inhibits fibrin sheath adherence and encrustation by blood or other bodily fluids, as sometimes encountered with single tube catheters.
In use, fluid flowing distally through the first lumen 114 splits into the lumens 116 as it leaves the proximal portion 118 and enters the distal end 110 of the device 100. In one embodiment, one or all of the lumens 116 taper toward the distal end 110 (i.e., a cross-sectional area of the lumen may grow gradually smaller from the proximal end of the corresponding branch 112 toward the distal end thereof). In addition, any or all of the branches 112 may be angled relative to one another, depending upon a desired performance aspect. That is, longitudinal axes of the branches 112 may be set at any desired angle relative to a longitudinal axis of a distal end of the proximal portion of the shaft 106 to achieve a desired orientation of the branches 112 relative to one another. Preferably, this angle is minimized to between 0 and 45 degrees, and more preferably between 0 and 15 degrees, such that the branches are in-line with the catheter longitudinal axis. As an example, the proximal portion 118 near the distal end 110 can define a first longitudinal axis and the first and second branches 112 can define second and third longitudinal axes, respectively. The a preferred embodiment, the second axis extends at an angle of less than 45 degrees from the first axis and the third axis is substantially co-axial with the first axis.
Those skilled in the art will understand that, for a catheter portion 102 including more than two branches 112, the various branches 112 may be located in a single plane or a plurality of planes. The length of each branch is preferably less than about eight centimeters from most venous access applications.
The distal end 110, including the branches 112 may be delivered to a target area of the body in the same manner used for conventional split tip catheters as will be understood by those skilled in the art. The branches 112 may be temporarily bonded to one another or held together by an insertion device to facilitate the passage of the catheter portion 102 through intervening tissue with a minimum of trauma thereto.
It will be understood by those skilled in the art that a catheter according to the present invention may include multiple lumens through a proximal part thereof so long as at least one of these proximal lumens opens to a plurality of lumens in separate distal branches of the catheter. That is, a catheter having a proximal part including two lumens will include at least three branches at a distal end thereof with each branch including a lumen open to one or more of the lumens of the proximal part.
It will be apparent to those skilled in the art that various modifications and variations can be made in the structure and methodology of the present invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided that they come within the scope of the appended claims and their equivalents.