The present invention relates generally to medical instrumentation and more specifically to a method for inserting a multi-lumen catheter with a selectively attachable hub assembly that allows the catheter tip to be accurately positioned prior to subcutaneous tunneling.
Catheters, generally, are hollow, flexible tubes for insertion into a body cavity, duct, or vessel to allow the passage of fluids or distend a passageway. Catheters are often used for temporary or long-term dialysis treatment. Dialysis treatment provides for blood to be withdrawn from the patient, purified, and then returned to the patient. Thus, in dialysis treatment, catheters are used to allow passage of a patient""s blood into and out of the patient""s body. For optimal performance during dialysis treatment, the catheter tips, both in-flow and out-flow, should be placed in close proximity to the heart. Typically, medical personnel use either a double lumen catheter or two single lumen catheters. Both types, however, present certain deficiencies.
While double lumen catheters (e.g., U.S. Pat. No. 4,895,561) allow for a single venous insertion of the catheter into the desired vein, double lumen catheters typically do not provide for accuracy of catheter tip placement. Due to differences among patients, optimal tip position accuracy of catheter tip placement. Due to differences among patients, optimal tip position varies from patient to patient. Non-optimal tip position may significantly lower flow values, resulting in less effective dialysis treatment. For current double lumen catheters, a physician must make an estimate regarding the appropriate catheter tube length prior to beginning the procedure of catheterization. Then, a subcutaneous tunnel is made from the preferred end position of the hub assembly, namely, away from the neck of the patient in order to allow for more convenient access to the dialysis treatment equipment. The double lumen catheter tube is then tunneled forwardly into the patient""s vein. The initial estimate and subsequent forward tunneling may result in less than optimal tip placement.
With the use of two independent catheters (e.g., U.S. Pat. Nos. 5,776,111 and 5,624,413) the problem of tip placement is addressed. The hub assembly of each catheter is removable from the tube and tip portion of the catheter, thereby allowing the catheter tip to be placed directly into the vein and advanced into the desired position. Then, the proximal end of the catheter can be reversed tunneled and trimmed to a desired length. Thereafter, the hub assembly is attached. Deficiencies, however, exist in this method of catheterization as well. One problem associated with this method is that this method requires two separate venous insertions, namely, two tunnels and two of each accessory instrument used for the procedure. Therefore, there is increased surgical time required to place two catheters, there are two wound entry sites which doubles the risk of post-surgical infection, and the two catheters together are significantly larger in diameter than one double lumen catheter.
The present invention is a method for inserting a multi-lumen catheter assembly into an area to be catheterized The multi-lumen catheter assembly is comprised of (a) a multi-lumen catheter tube with a distal portion and a proximal portion, the catheter tube having a first lumen and a second lumen, (b) an attachable hub assembly, the hub assembly having a (i) a hub body with a distal portion and a proximal portion, the proximal portion of the hub body being externally threaded, the hub body being formed about a first cannula and a second cannula, each of the cannula having a proximal portion and a distal portion, (ii) a connection cover having a proximal portion and a distal portion, the connection cover fitting axially about the distal portion of the catheter tube, the distal portion of the connection cover being internally threaded, and (iii) a compression sleeve, the compression sleeve fitting axially about the distal portion of the catheter tube and the proximal portions of the first and second cannulae. The first lumen and the first cannula each have first indicator associated therewith, and the second lumen and the second cannula each have a second indicator associated therewith.
The method comprising the steps of making an incision near the area to be catheterized; inserting the proximal portion of the multi-lumen catheter tube into the area to be catheterized; creating a subcutaneous tunnel, wherein a first end of the subcutaneous tunnel is the incision near the area to be catheterized; routing the distal portion of the catheter tube through the subcutaneous tunnel beginning at the first end and exiting through a second end of the subcutaneous tunnel; and attaching the proximal portion of the hub body to the distal portion of the catheter tube.
The step of attaching the hub body to the catheter tube is further comprised of the steps of backfitting the connection cover over the distal portion of the catheter tube; backfitting the compression sleeve over the distal portion of the catheter tube; matching the first indicator associated with the first lumen with the first indicator associated with the first cannula, and inserting the proximal portion of the first cannula into the first lumen of the distal portion of the catheter tube, to create fluid communication between the first cannula and the first lumen; and matching the second indicator associated with the second lumen with the second indicator associated with the second cannula, and inserting the proximal portion of the second cannula into the second lumen of the distal portion of the catheter tube, to create fluid communication between the second cannula and the second lumen; compressing the connection between the first and second cannulae and the first and second lumens of the catheter tube by sliding the compression sleeve over the proximal portion of the first and second cannulae that have been inserted into the first and second lumens of the distal portion of the catheter tube, and connecting the distal portion of the connection cover to the proximal portion of the hub body by turning the connection cover so that the female threaded portion of the connection cover engages the male threaded portion of the hub body, such that the catheter tube is securely attached to the hub body.
These and other aspects of the present invention as disclosed herein will become apparent to those skilled in the art after a reading of the following description of the preferred embodiments and drawings. The description and drawings are for the purpose of describing a preferred embodiment of the invention and are not intended to limit the present invention.
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