The 2006 Kidney Disease Outcomes Quality Initiative (KDOQI) guidelines recommend that each institution should determine whether percutaneous thrombectomy with angioplasty or surgical thrombectomy with graft revision is preferred based on the expertise of the center.^6,11 Systemic thrombolysis or anticoagulation is not supported in this setting.

Clotted Vascular Access Catheters

Although many catheters are used on a temporary basis (Quinton catheter), a growing number of patients use vascular catheters as permanent hemodialysis access (permacath).¹² Thrombosis is a major cause of dysfunction in these catheters, likely secondary to activation of the contact coagulation cascade by a relatively bioincompatible device.¹³

The emergency physician should be familiar with the use of catheter-directed tPA as a solution to a mechanical malfunction of tunneled dialysis catheters.¹⁴ This is a simple technique that is easily done in any emergency department setting.

The minimum dose of tPA required to produce a clinically important thrombolytic effect is unknown. Success has frequently been achieved with administration of 2 mg tPA;¹³ however, there is some evidence that as little as 1 mg per lumen may be effective. Further investigation in this area is needed and would be quite feasible to perform.¹⁴

An example of catheter-directed tPA protocol is described in Table 1.¹⁵ The medication could be prepared in advance by the pharmacy department to be readily available for use in any emergency department.

Currently tPA is available only in 50-mg vials, so it must be divided into appropriately sized aliquots before use. Furthermore, these aliquots must be stored at –20°C until administration.

If the recommended treatments are unsuccessful or if the problem quickly recurs, a radiographic study using contrast should be performed and a catheter exchange should be done when appropriate. Although some institutions’ policy is to treat all catheters with poor blood flow rates with tPA as the initial intervention, the ultimate decision is made by the surgical or interventional radiology team.¹²