Central venous catheter-related thrombosis in clinically asymptomatic oncologic patients: a phlebographic study.

Fifty-seven oncologic patients with short- or long-term central venous catheters (CVCs) and without clinical signs of axillary-subclavian thrombosis were evaluated phlebographically. Different degrees of incomplete thrombosis were found in 26 patients (45.5%) and complete thrombosis, clinically silent, was found in six patients (10.5%). A fibrin sleeve around the CVC was radiologically demonstrated in 45 (78%) patients, 21 of them (46%) with negative standard venogram. Only in four patients there was no evidence of fibrin sleeve or parietal thrombosis. There were no significant differences between patients with long-term and short-term CVCs. We conclude that parietal thrombosis of the axillary-subclavian veins is a frequent event, even if there is no clinical evidence of flow obstruction and we confirm in vivo that a fibrin coating of the CVCs is present in the majority of the cases.