Intravascular linear thrombus after catheter removal: Sonographic appearance mimicking retained catheter fragment

Background: A common complication of central catheters is vascular thrombosis. We have observed that the remaining thrombus can sonographically simulate the appearance of the catheter itself, suggesting that the catheter may have broken. Objective: To describe the difference in the sonographic appearance of an intravascular linear thrombus and a retained catheter. Patients and methods: The study comprised 11 infants who were born between 1 January 2000 and 31 December 2001 and had at least one sonographic examination after removal of a central venous or arterial catheter, in whom a residual thrombus had a sonographic appearance simulating the appearance of the catheter itself. Results: In all of our cases the thrombus appeared as two parallel hyperechoic lines. In comparison to the sonographic appearance of a true catheter, these lines were less sharply demarcated, not quite geometrically parallel, less echogenic, and did not shadow or have reverberation artifacts. Conclusions: Although the sonographic appearance of a residual linear thrombus may closely resemble the sonographic appearance of a retained catheter fragment, appreciation of the subtle differences between the two is important, and could obviate the necessity for more invasive procedures.