Selective venous thrombolysis with the nipple-balloon catheter: Comparative evaluation in vivo

PURPOSE: To compare in an animal model of deep vein thrombosis, an intramur al drug delivery catheter, the nipple-balloon catheter, with an occlusion b alloon-infusion guide wire system, MATERIALS AND METHODS: Ten juvenile pigs were used for the study. Deep vein thrombosis was induced in both hind limbs by using a previously described technique. Heparin was administered 30 minutes later (2,500 IU intravenousl y) and bilateral thrombolysis was attempted with use of 8 mg of alteplase a s a 0.25 mg/mL solution containing heparin 50 IU/mL (n = 10) and sodium/meg lumine ioxaglate 40 mgI2/mL (n = 5), In one limb, the external iliac vein w as endoluminally occluded, and 0.8 mL of alteplase was administered every 3 minutes through a multisideport infusion wire placed coaxially through the balloon catheter, On the other side, a nipple-balloon catheter was used: a lteplase was injected as two 0.4-mL aliquots every 3 minutes in overlapping segments of the vessel, flood samples were taken at predetermined interval s to determine the partial thromboplastin time and plasma fibrinogen concen tration. At autopsy, the thrombus mass in the iliofemoral veins was measure d, and the extent of residual thrombosis in the venous tributaries was grad ed at four sites. The heart and the lungs were also examined for thromboemb oli (n = 5), Venous specimens were then subjected to X-ray fluorescence spe ctrometry to determine iodine content (n = 5), RESULTS: Bilateral thrombolysis could be successfully completed in all anim als. No procedural problem associated with the use of the nipple-balloon ca theter was encountered, The mass of residual thrombus in the axial veins wa s significantly lower in this group (P = .005), The drug delivery system us ed did not appreciably influence thrombolysis in the tributaries. Signs of macroscopic damage to the veins were not observed in any animal. None of th e venous specimens had detectable levels of iodine. Small thromboemboli wer e found in the pulmonary circulation in three of five animals, Fibrinogen l evels did not decrease during the procedure, CONCLUSIONS: The significantly lower residual thrombus burden associated wi th use of the nipple-balloon catheter suggests that the device may have the potential to be an effective delivery system for selective thrombolysis in veins.