The vascular access port has evolved from being an intravascular access port into a multi-purpose access port for use in intestinal, biliary, intraspinal, cranial, ventricular, and other applications. It is available in a variety of configurations for most species and catheter sizes. The catheter may be pre-attached during manufacture or attached intraoperatively by the surgeon. These ports are fabricated from the highest quality biomaterials.
Ports are entirely implanted catheter devices which do not exit through the animal’s skin. There is little concern about the animal disturbing the port thereby obviating the need for a jacket or other protective apparatus. Because there is no chronic exit site wound, infection risks associated with ports are considerably lower than with external catheters. The use of ports has provided many new research opportunities, and it represents a refined technique which has reduced animal use and minimized stress.
The port was originally intended for intermittent bolus infusions and periodic sampling and access, but it is now widely used in protracted and continuous infusions. The port is also used in a tethered model for longer boluses (one hour, for example) or for intermittent periods of blood pressure monitoring.
Catheter Biomaterials
The field of biomaterials for intravascular catheters has moved relatively slowly over the past three decades. Silicone rubber continues to be the most common material; however, polyurethanes have proven to be more hemocompatible than silicone. And the CBAS™ heparin coated polyurethane has proven to be the most thromboresistant material of all available technologies. This catalog offers a full range of silicone, polyurethane, and CBAS™-coated polyurethane catheters in sizes for all species.
Rounded Tips
Another vital catheter feature is the rounded distal tip. Both data and intuition confirm the benefits. The rounded tip is less traumatic to the intimal lining of blood vessels. Square cut or bevel cut catheters have sharp edges which irritate the blood vessel’s intimal lining thus hastening the host’s thrombogenic response. Rounded tips are available on polyurethane and CBAS™-coated polyurethane catheters.
CBAS™ Long-Term Heparin Coating
The Carmeda BioActive Surface (CBAS™) is the product of Carmeda AB in Stockholm, Sweden. Carmeda has an extensive bibliography of CBAS™ applications, particularly in human-use devices. CBAS™ applications in humans include central venous catheters, coronary stents, ventricular assist devices, extracorporeal blood circuits, blood sampling devices, and vascular grafts. CBAS™ is used to coat devices from J&J, Medtronic, and Gore. In lab animal research, CBAS™-coated catheters are used for arterial and venous access. Also, CBAS™ provides dramatic improvement in catheter patency for chronic lymphatic access.
CBAS™ is a patented process for applying heparin to the surfaces of biomaterials. Unlike TDMAC heparin, the CBAS™ covalent bonds last several months. The "active sequence" of the heparin molecule serves to halt the clotting cascade.
The endothelial lining of blood vessels contains a heparin-like substance which performs like CBAS™. The novel aspect of CBAS™ is that the active sequence remains available over and over to bind with antithrombin. No other coating can achieve this long-term function.
CBAS™ is the most respected thromboresistant coating available in the human-use medical device industry. Unlike hydrogels, CBAS™ is bioactive, not passive. It has been proven repeatedly to minimize the thrombogenecity of intravascular devices.
CBAS™ is not consumed. The heparin "active sequence" repeatedly binds to antithrombin to prevent clotting. As such, half-life is not an issue. CBAS™ is "end-point attached" to the catheter surface and does not elute into the bloodstream.