Management of occlusion and thrombosis associated with long-term indwelling central venous catheters

Abstract

Long-term central venous catheters (CVCs) are important instruments in the care of patients with chronic illnesses, but catheter occlusions and catheter-related thromboses are common complications that can result from their use. In this Review, we summarise management of these complications. Mechanical CVC occlusions need cause-specific treatment, whereas thrombotic occlusions usually resolve with thrombolytic treatment, such as alteplase. Prophylaxis with thrombolytic flushes might prevent CVC infections and catheter-related thromboses, but confirmatory studies and cost-effectiveness analysis of this approach are needed. Risk factors for catheter-related thromboses include previous catheter infections, malposition of the catheter tip, and prothrombotic states. Catheter-related thromboses can lead to catheter infection, pulmonary embolism, and post-thrombotic syndrome. Catheter-related thromboses are usually diagnosed by Doppler ultrasonography or venography and treated with anticoagulation therapy for 6 weeks to a year, dependent on the extent of the thrombus, response to initial therapy, and whether thrombophilic factors persist. Prevention of catheter-related thromboses includes proper positioning of the CVC and prevention of infections; anticoagulation prophylaxis is not currently recommended.

Figure 1

The pinch-off syndrome. The catheter passes through the narrow angle between the first rib and the lateral portion of the clavicle (the pinch-off area), placing it at risk for compression or transection. In the left panel, a 3-dimensional computed tomography image, the catheter passes through the pinch-off area parallel to the subclavian vein then inserts into the superior vena cava. In the right panel, the catheter inserts into the subclavian vein and is intravenous when it passes through the pinch-off area. Catheters that are external to the subclavian vein when they pass through the pinch-off area, as in the left panel, have a greater risk of pinch-off syndrome and fracture.

Figure 2

Types of thrombotic occlusion.

Figure 3

Algorithm for management of a central venous catheter obstruction. CVC: central venous catheter; DVT: deep-vein thrombosis; MRI: magnetic resonance imaging; MRA: magnetic resonance angiography.

Figure 4

Mechanism of action of tissue plasminogen activator. Tissue plasminogen activator catalyzes the conversion of plasminogen to plasmin, which then cleaves fibrin into fibrin degradation products to dissolve the thrombus.

Figure 5

Cumulative incidence of catheter clearance after administering a thrombolytic agent. In the 16 studies represented in this figure, if the catheter did not clear within 120 min, a second dose of the agent was administered.–, –

Figure 6

Incidence of catheter-related thrombosis in patients who received prophylaxis with low-molecular-weight heparin or placebo in 7 randomized trials.– Only the study by Lagro et al included solely symptomatic patients.

Figure 7

Recommended algorithm for the management of catheter related thrombosis. CVC: central venous catheter, LMWH: low molecular weight heparin. *The duration of anticoagulation therapy required depends on a variety of clinical factors. In patients with no prothrombotic risk factors who’s CVC has been removed, most consider 3 months of anticoagulation sufficient. In patients with cancer, low molecular weight heparin is preferred over warfarin since the rate of recurrent thrombosis is twice as high with warfarin, and the duration of anticoagulant therapy should be at least 6 months, and possibly one year or longer. ** If the CVC is removed after development of catheter-related thrombosis, no prothrombotic risk factors remain, and the clot is small and does not completely obstruct the vein, 6 weeks of anticoagulation may be sufficient. A longer duration of anticoagulation is recommended for large, obstructing clots and when prothrombotic risk factors are present after CVC removal. *** In a patient with catheter-related thrombosis whose CVC is left in place after 3 to 12 months of anticoagulation therapy, prophylactic doses of anticoagulant therapy are recommended, especially if other prothrombotic risk factors are present, as is the case for most patients with cancer.