[Role of low molecular weight heparins in prophylaxis of thromboembolic events on oncological patients with indwelling central venous catheter].

Background And Objective: Our study was designed to assess the incidence of thrombosis in the upper limbs and of pulmonary embolism in oncological patients with indwelling central venous catheters, and to evaluate, also, the potential role of LMWH to prevent these events.

Patients And Methods: Oncological patients undergoing placement of a central venous acccess (port-a-cath type) were treated with or without bemiparin in a non-randomized fashion. Assessment included clinical and radiological follow-up. A phlebography on the first day and ecodoppler on days 1th, 45th and 90th were performed. Patients received or not prophylactic bemiparin (3500UI/day) in a non-randomized way. The incidence of thrombosis in both groups was assessed as well as its relation with some risk factors.

Results: One hundred and forty eight patients were eligible; 19 thrombotic events were found. The incidence of symptomatic upper extremity thrombosis was 5.41%, asymptomatic thrombosis in 2.03% ; there was one case of pulmonary embolism ( 0,68%); catheter failure occurred in 2.70%; incidence of lower extremities deep venous thrombosis was 2.03%. There was a higher percentage of events in the group of patients treated with bemiparin than in the not treated individuals (9.4%), although the difference did not reach statistical significance (p=0.27). The only risk factors reaching statistical significance were the prothrombin time, high blood pressure and overweight.

Conclusions: Central venous catheters are very useful in oncology. The procedure was related with a low percentage of thrombotic complications. Sodic bemiparin does not reduce the thrombotic risk in these patients.