Thrombus on indwelling central venous catheters: the histopathology of "Fibrin sheaths".

Objective: 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 histopathology.

Methods: Ten catheter strippings were performed and the removed material was studied grossly and microscopically.

Results: The histologic specimens showed thrombus both with and without a proteinaceous sheath.

Conclusions: Dialysis catheters fail because of thrombus formation. This can occur in either the absence or presence of a protein coating on the catheter, the so-called "fibrin sheath."