Catheter with elongated side holes

#The present invention relates to catheters and more particularly to a catheter having one or more lumens therein and an elongated and generally slot-shaped side hole extending through the sidewall of the catheter.

#Single or multiple lumen catheters are well known in the medical field and are widely used in medical procedures such as hemodialysis or other procedures wherein it is desirable to inject or remove fluids through one or more lumens of the catheter. For example, in hemodialysis it is desirable to introduce blood into a vein or other vessel of a patient through a first lumen while simultaneously removing a corresponding amount of blood from the patient through a second lumen of the catheter. In certain situations, it may also be desirable to have a third lumen extending through the catheter to allow a medication to be injected therethrough without interfering with the operation of the first or second lumens.

#The currently available single or multiple lumen catheters frequently have an opening at the distal end thereof and one or more openings or holes along the sidewall of the catheter. During hemodialysis, the arterial or intake lumen is used to remove blood from the patient. This intake lumen typically opens along the sidewall of the catheter. In use, the side opening may occasionally become completely or partially occluded by the interior wall of the patient's blood vessel when the catheter has been inserted. The complete or partial occlusion of the side opening will significantly reduce the flow of blood through the intake lumen of the catheter and may also damage the interior wall of the patient's blood vessel.

#FIG. 1 is an elevated left side view of a catheter of the present invention;

#FIG. 2 is an enlarged elevated front side view of the distal portion of the embodiment shown in FIG. 1;

#FIG. 2B is an enlarged elevated front side view of an alternate embodiment of the distal portion of the embodiment shown in FIG. 1.

#As shown in the drawings, the preferred form of the overall catheter assembly 10 of the present invention is generally similar to the dual lumen hemodialysis catheter shown in U.S. Pat. No. 4,583,968 granted to Mahurkar on Apr. 22, 1986. The catheter assembly 10 generally includes an elongate and slightly oval-shaped body portion 12 having a tip member 14 on the distal end thereof and a Y-shaped connector hub 16 on the proximal end thereof. As shown in FIG. 1, the proximal end of the Y-connector includes extension members 18 and 20 thereon. As used herein, the term "proximal" is intended to refer to the end or portion of a member which is normally oriented or positioned away from the patient while the term "distal" refers to the end or portion of a member in use which is nearest to the patient. Although the preferred form of the present invention is described herein with respect to multiple lumen catheters, it is intended that the present invention may also be used with nearly any catheter having one of more lumens therein including angiographic or various diagnostic catheters.

#The body portion 12 of the preferred embodiment of the catheter assembly 10 is hollow except for a generally flat, longitudinal septum 22 which divides the interior of the hollow cylinder into two preferably parallel lumens 24 and 26, with each lumen, 24 and 26, having a generally D-shaped cross section as shown in FIG. 7. As illustrated by the arrows in FIG. 6, the lumen 24 is the blood intake or arterial lumen, and the lumen 26 is the blood return or venous lumen.

#At the distal end of the catheter assembly 10, the exterior surface of the body portion 12 merges into the smoothly tapered conical tip member 14. On the inside of the body portion 12, the blood return lumen 26 extends longitudinally all the way through the tip member 14, bending slightly as it passes through the tip member 14 so that it opens at distal opening 28 near the center of the distal end of the tip member as can be seen in FIG. 6. Within the tip member 14 the preferred cross-sectional shape of the lumen 26 gradually changes from D-shaped at the proximal end of the tip member 14 to circular at the distal end of the tip member 14 at the distal opening 28 as shown in FIGS. 7 and 8. The cross-sectional diameter of the distal opening 28 is preferably maximized so that the blood return lumen 26 may not require a side opening therein. In order to provide longitudinal spacing between the distal openings of the two lumens 24 and 26, the blood intake lumen 24 is terminated at side opening 30 in the sidewall of the catheter as described more fully below.