Interventional Radiology: Venous
PICC Lines, Pasports, Tunnel Catheters and Central Lines

Also called: central venous access procedures

Central venous access procedures include ports (P.A.S.ports, a trade name), PICC lines, tunnel catheters and central lines. Venous access procedures are used to provide ready access to veins for the administration of medication and/or nutritional supplements. Central venous access procedures may be necessary for patients with veins too limited for normal IVs and for those undergoing a therapy where the drugs cannot be placed in the small veins of the arm, but require placement in the large veins near the heart. Generally, the interventional radiologist performs central venous access procedures, when placement of moderate, long term, permanent or perhaps indefinite venous access is needed. The type of catheter employed depends on the type and term of therapy to be performed.

PICC line (peripherally inserted central catheter) is the most commonly performed venous access procedure. PICC lines are used when daily acces to veins is needed over a long period of time (usually over two weeks, possibly 6 to 8 weeks). Placement of a PICC line involves insertion of a small tube into the upper arm. The PICC line is guided under fluoroscopic imaging through the veins to the superior vena cava (the largest vein near the heart). A portion of the tube is left accessible from the patient externally with one or two openings in the tube to administer medications. While not infusing medications, the exposed portion of the tube is covered under a dressing (gauze pad). PICC lines must be flushed before and after infusion.

Daily infusion (injection) into a PICC line does increase the risk of infection and therefore PICC lines are not considered a permanent alternative for venous access. If problems develop before treatment ends, PICC lines are generally simple to replace.

Ports (P.A.S. port, Port-a-cath trade names) are used when a therapy, such as chemotherapy, requires intermittent/interval high dose administration of drugs to the central veins (near the heart). Ports are used when infusion is needed for periods such as one week each month or once every other week as opposed to administration every day.

Radiologists typically implant a port (permanently) in the arm, chest or other areas completely under the skin. After the incision heals nothing but a small scar and a bump are visible on the patient allowing freedom of movement. A port is a small almond shaped device connected to a tube (catheter), which runs through the vein and ends near the heart. Medications and fluids may be administered directly into the bloodstream with a simple injection through the skin and into the port. Maintenance of the port is fairly limited. Ports require flushing with heparin (a saline solution) after infusion and about once a month to prevent clots when not in use.

Tunnel catheters (also called: tunnel cuffed catheters or Hickman catheters, Groshong Catheters or Perma-caths) prevent the spread of bacteria along the pathway of a catheter (access tract) and enable the "scarring in" of the catheter to help keep it in place. Tunnel catheters are most often employed in dialysis patients and those who require ongoing nutrition via veins for an indefinite period.

Tunnel catheters require daily flushing. A clot or tissue may develop around the exit end of a tunnel catheter or port impairing its function. In this circumstance, venous catheter / port contrast injection and stripping, can be performed by the radiologist without removing the catheter or port.