Thrombus on indwelling central venous catheters: The histopathology of "fibrin sheaths"

Purpose: Central venous catheters (CVC) may fail for many reasons, though " fibrin sheaths" blocking catheter ports are usually implicated. We examined the sheaths removed from dialysis catheters to determine their histopathol ogy. Methods: Ten catheter strippings were performed and the removed material wa s studied grossly and microscopically. Results: The histologic specimens showed thrombus both with and without a p roteinaceous sheath. Conclusion: Dialysis catheters fail because of thrombus formation. This can occur in either the absence or presence of a protein coating on the cathet er, the so-called "fibrin sheath.".