Central line thrombosis in patients with cancer.

Central venous catheters are used frequently to care for patients with cancer and often serve as long-term venous access. Catheter-related central venous thrombosis is a serious and common complication in these patients. The incidence of this event ranges from 2 to 40%. Potential risk factors are catheter position, size of the catheter, and perhaps site of insertion. The diagnosis of catheter-associated deep venous thrombosis may be difficult. Doppler ultrasound has a lower accuracy in this setting than it does in symptomatic lower extremity venous thrombosis. No clinical management studies have validated the practice of withholding anticoagulant therapy in patients with a negative Doppler ultrasound. The practice of prophylaxis with low-dose warfarin or low-molecular-weight heparin has been recommended, although results from recent studies have called this into question. Larger, prospective, randomized trials with a uniform population of patients or stratification of risk factors will be essential to address this issue further.