Subclavian venous thrombosis due to indwelling catheters: a prospective study on 52 patients.

Clinical occurrence of subclavian venous thrombosis due to indwelling catheters is rare, but there is some evidence that subclinical thrombosis frequently occurs. It is purpose of this study to report the results of a prospective investigation in patients with subclavian vein catheters. Fifty-two patients admitted to the Istituto Nazionale Tumori of Milan and candidate to infraclavicular percutaneous catheterization of the subclavian vein were evaluated. There were 26 polyvinyl chloride and 26 rubber silicone catheters, which were correctly positioned in the superior vena cava-atrium. Average duration of the intravenous stay was 12.8 days. Asymptomatic thrombosis was venographically demonstrated in 46.1% of the polyvinyl chloride catheters and in 11.5% of the silicone ones (p = 0.005). The average age of catheters with or without thrombosis was 10.8 and 13.8 days, respectively. Addition of heparin to the infusate (1 U/ml) did not reduce the thrombosis rate in polyvinyl chloride or in silicone catheters, but risk of thrombosis was significantly higher (p = 0.03) in polyvinyl chloride catheters without heparin in comparison to the silicone ones. Osmolarity of the infusional fluid, manipulation during the cannulation, colonization of the catheter tip, and duration of the intravenous stay of the catheter apparently did not influence the rate of thrombosis. Since the natural history of the thrombotic subclavian veins is not known, some caution must be paid to repeat the percutaneous cannulation of the same vein and the change the catheter over a guidewire.