Incidence of ultrasound-detected asymptomatic long-term central vein catheter-related thrombosis and fibrin sheath in cancer patients.

BACKGROUND

Most central venous catheter (CVC)-related deep vein thromboses (DVT) are asymptomatic and their incidence and clinical relevance are still under debate. Data on CVC-related fibrin sheaths are scarce. We investigated the incidence of asymptomatic DVT and fibrin sheaths in cancer patients with long-term CVC implantation who underwent Doppler ultrasound surveillance at 1, 6, and 12 months after implantation. Effects of low-weight molecular heparin (LWMH) therapy on DVT and fibrin sheaths were also analyzed.

MATERIAL AND METHODS

This prospective study was performed on a large cohort (n = 400) of patients with cancer aged >18 requiring long-term CVC implantation for chemotherapy infusion. CVC was implanted by a trained qualified staff, according to standardized protocol in a specific surgery. Patients underwent ultrasound examination at 1 and 6 months after CVC implantation to detect 'early' (1 month) and 'late' (6 months) asymptomatic DVT or fibrin sheaths incidence. Sixty-nine patients underwent US examination also 12 months after CVC implantation.

RESULTS

The incidence of CVC-related thrombosis was 0.10 events per 1000 catheter days. Anticoagulation therapy with LWMH resolved 50% of DVT, but no CVC needed removing. Incidence of new onset fibrin sheaths was 0.71 events per 1000 catheter days. Fibrin sheaths resolution occurred independently of LWMH therapy.

DISCUSSION

The incidence of asymptomatic DVT in our patients with long-term CVC is very low and does not represent per se an indication for removal of functioning CVC in patients with cancer. Fibrin sheaths are frequent (13%) and never associated with CVC dysfunction.

CONCLUSION

Asymptomatic DVT and fibrin sheaths do not represent per se an indication for removal of functioning CVC in cancer patients who need central vein access.