Hemodialysis access system

Abstract

A medical blood access system used for hemodialysis treatment to enable blood withdrawal for processing of blood by an external apparatus and return the same blood to a patient, comprising an interfacial fluid conduit between the machine and patient's blood supply which is repeatedly connectable along a guided pathway passing through epidermis and subcutaneous tissue via a naturally formed tissue tract to enter blood space, providing improved patient safely, convenience, effective prophylaxis, without bleeding or tissue trauma or pain, and is executable by the patient to precisely connect and disconnect with minimal disfigurement or life restrictions, and is useable on virtually all patients soon after placement and is robust and safe to high blood flow.

1 . A medical blood access system used for hemodialysis treatment to enable blood withdrawal for processing of blood by an external apparatus and return the same blood to a patient, comprising an interfacial fluid conduit between the machine and patient's blood supply which is repeatedly connectable along a guided pathway passing through epidermis and subcutaneous tissue via a naturally formed tissue tract to enter blood space, providing improved patient safely, convenience, effective prophylaxis, without bleeding or tissue trauma or pain, and is executable by the patient to precisely connect and disconnect with minimal disfigurement or life restrictions, and is useable on virtually all patients soon after placement and is robust and safe to high blood flow. 
     
     
         2 . A system according to  claim 1  wherein the system comprises a totally implanted port, with catheter and a tubular conduit called a needle assembly which couples with the port by inserting along a permanent passage through the subcutaneous tissue and into the port aperture and which is mechanically stopped at the proper docking position, creating an open transcutaneous flow path from the exterior of the patient to patient's vasculature, and a lock mechanism which can engage the needle assembly to hold the needle assembly within the port after insertion of the needle assembly. 
     
     
         3 . A system according to  claim 1  wherein the naturally formed tissue tract guides insertion of the needle assembly to engage precisely with the port. 
     
     
         4 . A system according to  claim 1  wherein prophylaxis is provided by a gel composition comprising antimicrobial action and lubricating action which can be instilled within the port blood passage and the tissue tract after hemodialysis treatment, during the disconnection procedure, to protect against microbial colonization within the blood pathway and the needle tract to prevent bloodstream and subcutaneous tissue infections and also provide easy penetration of the needle assembly along the tissue tract and during subsequent docking of the needle assembly with the port. 
     
     
         5 . A system according to  claim 1  wherein the tissue tract is induced to form in situ, and in alignment with the implanted port aperture, by the implanting surgeon during the port placement procedure, under full visualization and with freedom to select best pot/tract positioning, considering patient accessing needs and other surgical and medical concerns, using special tools to facilitate a precise alignment path and tissue formation which is fixed to the port and which is the means to help maintain proper alignment between the tissue tract and the aperture in the port. 
     
     
         6 . A system according to  claim 2  wherein the port comprises a housing, an internal passage with a septum closure which seals the distal side of the passage from the proximal side of the passage, a means for connecting the distal end of the passage with a catheter which is conventionally inserted into the vascular system at the time of placement, and a mechanical stop which blocks needle insertion at the correct position which is tactile sensed by the patient for positive feedback. 
     
     
         7 . A system according to  claim 6  wherein the port comprises a simple valve closure comprising a conventional port septum installed and positioned in the port housing such that the needle assembly is confined to penetrate the septum precisely, in a single path coincident with a slit or multiple intersecting slits formed in the septum, with a special needle comprising a non-cutting blunted tip which separates the slit or slits as the needle penetrates through the slit or slits without cutting or tearing the septum until the needle reaches a needle stop shoulder integral to the port housing, which provides exceptional puncture life with large needles. 
     
     
         8 . A system according to  claim 7  wherein the septum slit can be produced by several techniques including, for example, mechanical cutting, molding in place and laser cutting, to achieve an installation condition of alignment with the port aperture and sufficient compressive stresses to maintain fluid tightness in use and during quiescent periods. 
     
     
         9 . A system according to  claim 6  wherein the port housing comprises a feature on its outer surface similar to tube bead geometry which enables the tissue tact to form and become fixed in coincident alignment with the port aperture. 
     
     
         10 . A system according to  claim 6  wherein the port comprises a shape and surface fairing configured to enable tight membrane tissue encapsulation formation around the port and conjoin with the tissue tract. 
     
     
         11 . A system according to  claim 6  wherein the port comprises an aspect ratio which minimizes tensile stress in the epidermis and subcutaneous tissue and comprises means to fix the port to the body of a patient so as to minimize relative displacement between the tissue tract and the port. 
     
     
         12 . A system according to  claim 6  wherein the port enables retrograde passage of a flexible probe through the port and valve closure to exit the port's needle entry aperture, which is utilized as a template to create a precisely-pierced line through subcutaneous tissue and aligned with the implanted port. 
     
     
         13 . A system according to  claim 6  wherein the port comprises either (i) one flow path within the housing, along with other functional components including a septum closure, catheter dock, tissue tract fixing bead and needle lock, or (ii) more than one flow path in the same housing. 
     
     
         14 . A system according to  claim 13  wherein the port is used for hemodialysis and comprises two flow passages and functional means which enable a blood withdrawal circuit and a blood return circuit, and which enable lower blood flow through each corresponding catheter and tubular conduit which improves patency and provides a simple means to overcome bleed out from needle dislodgement. 
     
     
         15 . A system according to  claim 2  wherein the needle assembly comprises an stiff hyperemic cannula, a housing and a flexible fiber-like rod which can enter the cannula and protrude from the distal end thereof and be locked in place so that during insertion through the tissue tract, the rounded or conical shaped tip acts to spread apart the tissue tract without cutting as the needle assembly penetrates the tract and without bleeding or pain. 
     
     
         16 . Tools for initiating tissue tract formation to facilitate best alignment and fixation with a port aperture during surgical port placement, comprising:
 a piercing tool which is used in conjunction with the port to establish precise alignment; and   a “foreign body” tool which provides surface and establishes position within subcutaneous tissue to effect a tissue tract formation conjoined with the membrane capsule forming around the port under full visual access and allowing port position adjustment if necessary while the patient is somewhat less alert and to enable a contiguous conjoined membrane encapsulation with the port.   
     
     
         17 .- 20 . (canceled) 
     
     
         21 . A construct comprising a port implanted in a body beneath the surface of the skin, the port being connected to the interior of a vascular structure by a catheter and the port being connected to the surface of the skin by a tissue tract, with a septum being interposed between the catheter and the tissue tract, wherein the septum is selectively penetrable. 
     
     
         22 . A construct according to  claim 21  wherein a biocidal lock is disposed in the catheter between the septum and the vascular structure. 
     
     
         23 . A construct according to  claim 21  wherein a biocidal lock is disposed in the tissue tract between the septum and the surface of the skin. 
     
     
         24 . A construct according to  claim 23  wherein the tissue tract is selectively closed adjacent to the surface of the skin. 
     
     
         25 . A construct according to  claim 24  wherein the tissue tract is selectively closed with a bandage. 
     
     
         26 . A construct according to  claim 24  wherein the tissue tract is in the form of a slit.