Systemic fat and thrombus embolization in patients undergoing total knee arthroplasty with regional heparinization

A double-blind, randomized, controlled study was undertaken to determine if a technique of intraoperative anticoagulation would decrease the incidence or severity of venous embolization after tourniquet release during total k nee arthroplasty. Sixty-six patients were randomized to receive either the heparin or placebo treatment. Transesophageal echocardiography was performe d before and after tourniquet release to detect embolic material in the rig ht atrium. Transient opacification of title right atrium was observed in al l patients within the first 30 seconds after tourniquet release. Regional l imb heparinization is not effective in reducing the intensity of right atri um opacification because much of the echogenic material was composed of fat rather than thrombus.