Management of thrombotic catheter occlusion with urokinase

Management of thrombotic catheter occlusion with urokinase

Central venous access devices (CVADs) play an important role in modern healthcare, providing essential access for therapies including dialysis, chemotherapy, parenteral nutrition and critical care interventions. However, one of the challenges associated with CVADs is occlusion, which can disrupt treatments, increase infection risks1-3 and lead to costly catheter replacements.

Catheter occlusion can occur in various medical settings, with each application facing distinct challenges.

Catheter occlusion can occur in various medical settings, with each application facing distinct challenges.

Close-up of a patient undergoing intravenous blood treatment with vascular access lines

Haemodialysis

Renal patients rely on CVADs for regular life-sustaining treatments. Catheter dysfunction is a critical issue that can disrupt or delay routine haemodialysis sessions, with knock-on effects for patients, hospital staff and resources.
Nurse preparing a male patient for intravenous therapy using a dialysis machine

Drug administration

CVADs are used to administer a variety of medications in oncology, haematology, ICU and gastroenterology settings. However, fibrin formation can cause these catheters to become occluded, hindering care and negatively affecting patient experiences.

How common is catheter occlusion?

How common is catheter occlusion?

CVAD occlusion is a frequent and disruptive issue that occurs in 14 to 36 % of patients within the first 1 to 2 years of catheter placement.4 In fact, more CVADs are removed due to dysfunction (43 %) than infection (32 %) every year.5 Certain patient groups face even higher risks – oncology patients, for instance, are particularly vulnerable due to the pro-thrombotic effects of many chemotherapy drugs, and haemodialysis patients often experience catheter-related complications due to blood stasis and clot formation.

Illustration of progressive thrombus dissolution within a blood vessel

How to recognise an occluded catheter

How to recognise an occluded catheter

An occluded catheter may present with the following signs.6

  • Increased resistance during infusion
  • Increased resistance during withdrawal
  • Difficulty or inability to withdraw blood
  • A significant drop in blood flow rate (BFR) below 300 ml/min during haemodialysis
  • A decrease in BFR of 10 % or more from the optimal rate during haemodialysis
Early recognition of these signs enables timely intervention with a thrombolytic agent, helping to prevent complications and catheter failure.

Types of catheter occlusion

Types of catheter occlusion

Catheter occlusions can develop from various thrombotic formations, each affecting catheter function in unique ways.

  1. Intraluminal clots account for 5 to 25 % of occlusions,4 and may occur independently or in combination with other types of blockages. They occur when stagnant blood inside a CVAD forms a clot, often due to loss of locking solution pressure. This can allow blood cells and debris to infiltrate the catheter tip.
  2. Fibrin tails develop when a fibrin clot forms a tail-like extension on one side of the CVAD. This disrupts flow dynamics and can make blood withdrawal difficult or impossible if the tail obstructs the catheter tip.6
  3. Mural thrombi form when blood clots adhere to the vessel wall at the catheter tip, often due to endothelial injury from catheter movement within the vein. Over time, they can enlarge and contribute to significant complications, including catheter dysfunction and an increased risk of infection.
  4. Fibrin sheaths are among the most common causes of thrombotic obstruction, and may begin forming as early as 24 hours after catheter insertion.4 In severe cases, they can fully encase the catheter, leading to an intermittent or complete blockage. Catheter-related sheaths can cover 33 to 100 % of the intravascular length.7
Comparative 3D illustration of thrombus morphologies: intraluminal clot, fibrin tails, mural thrombus, and fibrin sheath

The real-world impact of catheter dysfunction

The real-world impact of catheter dysfunction

Catheter occlusion isn’t just a minor inconvenience – it has far-reaching consequences for both patients and healthcare providers.

Empty hospital bed in a clinical treatment room with IV stand and medical tray

Patients may experience:

  • Disruptions to essential treatments, including dialysis and chemotherapy
  • Increased infection risk, as clots create an environment for bacterial growth1-3
  • Repeated catheter removal and replacement procedures
Healthcare professional taking notes in a fast-paced hospital ward with medical staff attending to patients

Occlusions also cause significant challenges for healthcare providers:8

  • Treatment delays can prolong hospital stays, increasing costs and straining resources
  • Nurses spend extra time troubleshooting occlusions, delaying care for other patients
  • Frequent catheter replacements significantly raise healthcare expenses

Discover more about Syner-KINASE

Discover more about Syner-KINASE

Medical stent partially blocked by arterial plaque buildup with fibrous tissue

Learn about catheter thrombosis and why thrombolytic therapy is essential

Syner-Kinase® Human Urokinase vials and packaging in 10,000, 25,000, and 100,000 IU doses

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Syner-KINASE®

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Watch expert-led discussions on thrombolysis for catheter blockages

Have questions or need more information?

Have questions or need more information?

Adverse events should be reported. Reporting forms and information can be found at www.mhra.gov.uk/yellowcard. 

Adverse events should also be reported to Syner-Med (PP) Ltd. Tel: +44 (0)208 655 6380

For Syner-KINASE prescribing information, click here

References

  1. Faintuch S, Salazar GMM. Malfunction of dialysis catheters: Management of fibrin sheath and related problems. Tech Vasc Interventional Rad. 2008;11:195-200.
  2. Van Rooden CJ et al. Infectious complications of central venous catheters increase the risk of catheter-related thrombosis in hematology patients: a prospective study. Journal of Clinical Oncology. 2005;23(12):2655-2660.
  3. Larsen M KS, et al. Use of cultivation-dependent and –independent techniques to assess contamination of central venous catheters: a pilot study. BMC Clinical Pathology. 2008;8:10. doi:10.1186/1472-6890-8-10
  4. Baskin JL, et al. Management of occlusion and thrombosis associated with long-term indwelling central venous catheters. The Lancet. 2009;374(9684):159-169. doi:10.1016/s0140-6736(09)60220-8
  5. Pengloan, J. Obstructed central venous catheters in haemodialysis. Hospital Pharmacy Europe. Accessed 29th February 2025. Available at: https://hospitalpharmacyeurope.com/clinical-zones/haematology/obstructed-central-venous-catheters-in-haemodialysis/
  6. Chan MR, et al. Haemodialysis Central Venous Catheter Dysfunction. Seminars in Dialysis. 2008;21(6):516-521. doi:10.1111/j.1525-139X.2008.00495.x
  7. Forauer AR. Jugular vein catheter placement: histologic features and development of catheter-related (fibrin) sheaths in a swine model. Radiology. 2006;240(2):427-34. doi: 10.1148/radiol.2402031129
  8. Syner-Med. 2025. Data on file. Resource impact model evaluating Syner-Kinase® for catheter occlusion management in NHS settings. Model version 1.0.