Background: Central venous catheters are essential to management of cancer patients. Thrombotic complications are potentially severe, but it is difficult to prescribe systematically a prophylactic treatment. So it is necessary to identify the higher risk patients who need a prophylaxis.
Aim: To identify factors associated with the development of clinically significant venous thrombosis in cancer patients with long-term catheters.
Methods: Monocentric prospective study about 5447 long-term central venous catheters inserted into patients receiving treatment for solid tumours (50% of breast cancers). Clinically significant catheter-related thromboses are confirmed by ultrasonography, phlebography or scanner.
Results: The median duration of catheter use is 147 days. There are 135 clinically significant catheter-related thromboses. The risk for thrombosis is 0.1149 events per 1000 device days. The incidence of symptomatic thrombosis is 0.9% at 30 days, 1.36% at 60 days, 1.83% at 90 days and 2.25% at 120 days. The multivariate analysis shows that female sex, duration of insertion procedure (more than 25 minutes) and place of insertion (femoral place) are factors associated with clinically significant venous thrombosis. The right subclavian insertion causes less risk. The catheters with their tip too "high" in the superior vena cava are systematically changed, so that the position of the catheter tip does not appear as a risk factor in our study. The disease stage and the type of treatments are not well examined.
Conclusions: A predictive score can be made with the three risk factors that have been identified. Thanks to this score it is possible to determine the patients with higher risk for clinically significant catheter-related venous thrombosis. These patients must be more frequently watched over and must receive a prophylactic treatment. The best prophylaxis has to be determined.