1. Field of the Invention
This invention relates to implantable fluid conducting tubing for medical use, and more particularly to unitary drainage tubing having a variable outer dimension along its length which is useful for conducting fluids from and/or to a site within the body of a patient.
2. Prior Art
Drainage tubing is frequently used to drain fluids from a wound site following surgery. It may also be used to deliver fluids to a site within the body. Such drains may simply comprise a tubular member, such as a Penrose drain, which is more or less flaccid and biocompatible. One end of the drain is temporarily implantable within the area of the body to be drained while the other end of the tubing extends from the patient to drain into a reservoir such as a bandage or jar. Problems associated with prior art drainage tubes are collapsing and sealage of the drainage conduit due to a lack of structural integrity in the walls of the drainage tube. Another problem is insufficient fenestrations or openings in the collecting end of the drainage tube (the end of the drainage tube embedded in the site to be drained) to facilitate the removal of body fluids therefrom. Yet another problem with prior art drainage tubes is the occlusion of the drainage path by clotted blood or other cellular debris from the wound site.
To overcome these problems, a variety of drainage tubes have been devised. Such tubes include solid implantable members having a tubular or channeled exterior surface which facilitate the drainage of fluid therethrough. Representative of such drainage tubes is the drain catheter described by Blake in U.S. Pat. No. 4,465,481, the disclosure of which is incorporated herein by reference. Such drainage tubes are normally characterized by a substantially uniform outer diameter along their length. Such a construction limits the size of the site to be drained (or perfused) to a relatively small volume immediately surrounding implanted drainage portion of the drainage tube. Others, such as the Jackson-Pratt wound drain are composite structures fabricated by joining together separate parts.