A permanent arterial access system

Now that long-term survival can be achieved in animals with mechanical circulatory devices, reliable permanent arterial access for physiologic and pharmacologic studies has become important. A novel approach has been developed eliminating the need for repeated arterial cannulation. The arterial access system (AAS) consists of a 7Fr Silastic catheter, which is threaded into the internal mammary artery, and an attached access well, which is placed in the subcutaneous tissue over the sixth rib. The AAS is implanted during the initial operation. The access well is punctured percutaneously with a 23 gauge needle to obtain arterial blood or to measure arterial pressure, and patency is maintained by flushing the access well with 2,000 U of heparin each week. The AAS was implanted in six calves (three with a total artificial heart, three with a ventricular assist device) for a mean duration of 124 days (range, 20-323 days). There were no infections related to the AAS, and none of them thrombosed. All of the AAS had excellent arterial wave forms when punctured. The AAs is simple to implant, provides reliable long-term arterial access, and does not appear to increase the risk of infection.