Evaluation of effect and distribution of heparin administered in vascular reconstructive surgery

Background. The aim of this study was to find out whether intravenously adm inistered heparin is distributed equally not only proximal but also distal to the arterial occlusion level in vascular reconstructive surgery, Methods. Ten consecutive patients (7 men and 3 women) with an average age o f 69.9 years (range, 51 to 76 years) who underwent graft replacement for ao rtic abdominal aneurysm from April to December 1994 were studied, Mean aort ic damp time was 76 minutes. Heparin sodium (100 U/kg) was administered int ravenously to keep activated clotting time (ACT) over 250 sees and was neut ralized by protamine sulfate (1 mg/kg) just after reperfusion. ACT, blood l actate and CPK-MM in the brachial and dorsal pedis artery were measured bef ore heparin administration (control), just after arterial occlusion, just b efore reperfusion and 10 minutes after protamine administration, Results. ACT was significantly prolonged after arterial occlusion and recov ered after protamine administration with no significant differences between proximal and distal values at each point. Lactate showed significant incre ase after arterial occlusion which was more remarkable distally, CPK-MM was all the way within the normal range. Conclusions, In vascular reconstructive surgery which requires temporary ar terial occlusion for as long as 80 minutes, the effect of heparin is excell ent and equal throughout the body by collateral vessels, and the metabolic influence due to blockade of the blood flow is not so critical as to lead t o cellular damage although anaerobic glycolysis is promoted distally due to hypoxia.