Experience of extensive vascular surgery on defibrase-defibrinogenated patients

Enhancement of arterial thrombolysis with native tissue type plasminogen activator by pretreatment with heparin or batroxobin: an angioscopic study

The enhancement of canine arterial thrombolysis with native tissue type plasminogen activator (nt-PA) obtained from human-derived normal cells by pretreatment with heparin or the defibrinogenating agent, batroxobin, was evaluated with angioscopy. The nt-PA, 0.25 mg/kg, was infused intravenously to lyse 1-hour-old thrombus (eight thrombosed arteries without medication, seven with nt-PA alone, seven with nt-PA and heparin, and seven with nt-PA plus batroxobin). Angioscopy provided a cross-sectional view of the vessel lumen with clear visualization of the thrombus. Thirty minutes after nt-PA infusion, the percent luminal obstruction decreased from 74 to 61 in nt-PA alone (p less than .025), from 77 to 37 in nt-PA plus heparin (p less than .005), and from 79 to 25 in nt-PA plus batroxobin (p less than .005). Fifteen minutes after drug infusion, plasma fibrinogen levels decreased to 89% of preinfusion value in nt-PA alone, to 84% in nt-PA plus heparin, and to less than 5% in nt-PA plus batroxobin. Thus rapid infusion of nt-PA alone provided slight thrombolytic effects. However, heparin and batroxobin showed marked enhancement of thrombolytic effects of nt-PA.

Preventive effects of batroxobin on experimental canine coronary thrombosis

The thrombolytic effects of urokinase (UK) and preventive effects of batroxobin, heparin, and aspirin on the recurrence of thrombosis in the coronary artery were studied in 118 anesthetized dogs with severe endothelial denudation and luminal stenosis of the coronary artery. Occlusive thrombi developed in 68 (58%) preparations (dogs), accompanied by a decrease of coronary blood flow and pressure, an electrocardiographic ST elevation, and epicardial cyanosis. An intravenous infusion of 20,000 IU/kg of UK reopened the occluded coronary artery in all 32 preparations with 1-h-old thrombi, in 6 (86%) of 7 preparations with 2-h-old thrombi, and in 5 (83%) of 6 preparations with 3-h-old thrombi. However, recanalization was not observed in preparations with thrombi more than 4-h-old. Occlusion recurred within 6 h after recanalization in 2 (18%) of 18 preparations pretreated with batroxobin (1-2 BU/kg) (p less than .005 vs. control UK group), in 1 (14%) of 7 preparations administered a continuous infusion of 30 U/kg per h of heparin (p less than .05 vs. control UK group), in 4 (57%) of 7 preparations pretreated with 2 mg/kg of aspirin, and in 7 (64%) of 11 preparations not pretreated (control UK group). Complete prevention was observed only in the group administered 2 BU/kg of batroxobin. Histologically, these thrombi closely simulated clinical arterial thrombi. Myocardial hemorrhage and contraction band necrosis were observed in the reperfused hearts. In conclusion, experimental canine coronary thrombi more than 4-h-old were resistant to thrombolytic therapy, and batroxobin and heparin were effective in the prevention of coronary reocclusion.

Vein surgery during defibrinogenation

The effect of defibrinogenation on thrombosis after thrombectomy and on the patency of Dacron femoral vein grafts has been studied in dogs. In all experiments the defibrinogenation significantly reduced thrombosis. Bleeding from suture lines and through the Dacron prostheses was not increased.