[Surface changes of intravenous catheters after antineoplastic chemotherapy]

[Venous thrombosis on central catheters in oncology]

Central venous catheters have considerably improved the comfort and safety of chemotherapy in cancer patients. However complications as thrombosis could occur and their incidence vary from 3.7 to 42% in oncology. Catheter placement induces modifications of vascular system with formation of a fibrin sleeve and/or a mural thrombus. Thrombosis origin is linked with catheter itself, its position and the biomaterial used. Hypercoagulable state in cancer results from the perturbation of blood flow, the composition of blood itself and the vessel wall, and increases the iatrogenic effects of indwelling catheters. Finally chemotherapy used in the treatment of cancer has been associated with an increased incidence of thromboembolic events, suggesting the proposal of an antithrombotic prophylaxis in cancer patients receiving chemotherapeutic agents through indwelling catheter.

Alteration of the inner surface of venous catheters by antineoplastic drugs

Septic complications and thrombosis are frequent causes of long-term venous catheter implantation failure and tend to occur more frequently in oncology than in patients using catheters for hyperalimentation only. The purpose of this in vitro study was to study extensively the inner surface behaviour and the possible changes in their mechanical properties of various silicone and polyurethane catheters after exposure to a flow of the most common antineoplastic drugs. Silicone catheters appeared to be the best choice for cytostatic drug infusions because of their chemical stability, but the addition of an opacifier imposes a protective inner and outer layer to improve their surface properties for biocompatibility.

[Polyurethane catheters and antineoplastic chemotherapy. An experimental study]

An in vitro study of the effect of cytotoxic drugs on polyurethane catheters was carried out. The drugs used--vincristine, doxorubicin, cisplatin and carmustine--damage the surface of silicone elastomer catheters. The irregularities produced seem to be preferential sites for thrombus formation and adhesion of bacterial microcolonies. Electron microscopy examination of the catheters dipped in the drug solutions for different time intervals revealed the appearance of different patterns of damage. The irregularities produced seemed to be less pronounced than for silicone catheters. Polyurethane was highly sensitive to doxorubicin. These changes could well have clinical repercussions. The compatibility of catheters and drugs should be routinely tested before being put on the market.