[A clinical study of thrombus formation associated with central venous catheterization].

Septic complication is one of the major problems associated with central venous catheterization. Thrombi produced around a catheter are regarded to a predisposing factor. However, few reports have focused on thrombus formation in clinical settings. We studied prospectively thrombus formation associated with central venous catheterization in 56 patients. Thrombus formation was identified in 39 cases (70%). In most cases, this thrombi formed around a catheter and were released into stream when the catheter was removed. However, complications attributable to the thrombi, such as pulmonary embolism were not observed. Then we tested four materials of catheters including vinylchloride, vinylchloride coated with heparine, polyurethane, and silicone to compare the incidence of thrombus formation. Thrombi were found regardless the catheter material when they were placed for more than 10 days. Cultures of blood, catheter tips and parts of catheters placed under the skin were performed to clarify the relation between thrombus formation and catheter-related sepsis. Positive culture was obtained only five cases but they were all associated with thrombus formation. These results suggest that central venous catheterization frequently results in thrombus formation, which would lead to catheter-related spesis.