For Rat Catheters, I’ll Have The CBAS® (Not The Fish)
Posted on Feb 18, 2012 by SolomonScientific
Infusion of test articles via a rat catheter in the jugular or femoral vein is a central procedure in drug safety testing. The most common premature endpoint of intravenous infusion models in rodents is tip occlusion. The most proven material-based solution to this problem is use of the CBAS® (Carmeda BioActive Surface from Gore Medical) coating on a polyurethane substrate. In addition to volumes of published papers documenting the benefits of CBAS in myriad blood-contacting device applications (e.g., stents, vascular grafts, artificial hearts, and hemodialysis catheters), Foley et al describe that CBAS-coated devices “can significantly prolong patency and cause less pathologic damage to the catheterized vessel”(1) in rat catheters.
In the 30-day Foley study, 9/9 subjects in the CBAS-coated polyurethane group were patent for both infusion and blood aspiration versus 3/8 in the uncoated polyurethane group. Additionally, 0/9 subjects in the CBAS-coated group yielded positive blood cultures, while 3/8 positive cultures were collected from subjects in the uncoated group. Finally, on necropsy, the CBAS-coated polyurethane “generally appeared to retard progressive development of the more advanced, often obstructive pathologic vascular changes observed microscopically in specimens from subjects of the uncoated…group.”(1)
CBAS-coated polyurethane tubes have benefits extending beyond lab animal intravenous infusion studies (i.e., in rodents, dogs, rabbits, pigs, and monkeys). Take, for example, peritoneal dialysis. Zareie et al report, “Our data clearly indicate that peritoneal catheters with a heparin coating reduce drop-out in a well-established PD [peritoneal dialysis] rat model.”(2) The control group used silicone tubes.
Gore-Tex® grafts with the Carmeda coating also showed improved patency in a chronic dog model compared to the uncoated grafts as reported by Begovac et al--“these results support the conclusion that a stable, CBAS-ePTFE surface provides improved thromboresistance and improved patency in canine interposition models.”(3)
(1) Foley P, Barthel C, Brausa H. Effect of covalently bound heparin coating on patency and biocompatibility of long-term indwelling catheters in the rat jugular vein. Comparative Medicine. 52(3):243-8. 2002.
(2) Zareie M, Keuning E, ter Wee P, et al. Improvement of a chronic rat model for peritoneal dialysis by using heparin-coated catheters. Advnaces in Peritoneal Dialysis. 20:150-4. 2004.
(3) Begovac P, Thomson R, Fisher J, et al. Improvements in GORE-TEX® vascular graft performance by Carmeda® BioActive Surface heparin immobilization. Eur J Vasc Endovasc Surg. 25:432-7. 2003.
