Thrombin activity associated with indwelling central venous catheters

Area of Science:

• Biomedical Engineering
• Hematology
• Vascular Biology

Background:

• Indwelling central venous catheters are prone to thrombotic complications, causing dysfunction and infection.
• The exact mechanisms of catheter-related thrombosis are not fully understood but involve vessel damage, stasis, and thrombin generation.
• Thrombin plays a critical role in the pathogenesis of catheter-associated thrombosis.

Purpose of the Study:

• To quantify thrombin activity on removed central venous catheters.
• To assess the efficacy of hirudin in inactivating catheter-associated thrombin.
• To investigate the relationship between catheter material and thrombin deposition.

Main Methods:

• Collected 48 central venous catheters from 46 patients.
• Sectioned catheters (distal, 5 cm, 15 cm proximal) for analysis.
• Measured thrombin activity using a chromogenic assay and assessed inhibition by hirudin.
• Utilized scanning electron microscopy to visualize fibrin deposition.

Main Results:

• Thrombin activity was detected on 40 out of 48 catheters (100 out of 144 segments).
• Mean thrombin activity was 132 +/- 27 microU/cm, with significant variability.
• Hirudin treatment reduced thrombin activity by over 85% (p < .001).
• Scanning electron microscopy revealed fibrin deposition not visible to the naked eye.

Conclusions:

• Indwelling central venous catheters frequently harbor active thrombin.
• This thrombin activity can be effectively inhibited by direct-acting agents like hirudin.
• Targeting catheter-associated thrombin may offer a strategy to mitigate thrombotic complications.