From the Guidelines
Catheter-directed thrombolysis is indicated for patients with acute limb ischemia (Rutherford categories I and IIa) of less than 14 days’ duration. This recommendation is based on the highest quality evidence available, which suggests that catheter-based thrombolysis is an effective and beneficial therapy for these patients 1. The procedure involves administering a thrombolytic agent, such as recombinant tissue plasminogen activator (rtPA, alteplase), directly into the thrombus via a multi-sidehole catheter.
Key Considerations
- The treatment typically continues for 24-48 hours with regular angiographic assessments to evaluate progress.
- Patients require close monitoring in an ICU setting with frequent neurovascular checks and laboratory monitoring (fibrinogen, PT/PTT, CBC).
- Catheter-directed thrombolysis is contraindicated in patients with immediately threatened limbs (Rutherford IIb or III) requiring urgent revascularization, those with absolute contraindications to thrombolysis (recent stroke, active bleeding, intracranial pathology), or when the ischemia has been present for more than 14 days.
Mechanism of Action
- Catheter-directed thrombolysis works by activating plasminogen to plasmin, which degrades fibrin clots, and is particularly effective for acute arterial occlusions where the thrombus is fresher and more susceptible to lysis.
- This approach allows for identification of underlying arterial lesions that may require additional intervention such as angioplasty or stenting once the thrombus is dissolved. The evidence from 1 and 1 supports the use of catheter-directed thrombolysis for acute limb ischemia, but the most recent and highest quality study 1 is given priority in making this recommendation.
From the Research
Indications for Lower Extremity Lysis for Acute Limb Ischemia
The indications for lower extremity lysis for acute limb ischemia include:
- Acute limb ischemia with a high risk of limb loss or significant morbidity 2, 3
- Decreased arterial perfusion resulting in inadequate tissue perfusion 3
- Patients with a suspicion of acute ischemia based on history and physical examination, who may benefit from heparin administration and vascular surgery consultation 2
- Etiology, duration, and location of vascular occlusion, which can influence the decision for endovascular thrombolysis or standard surgery 2
Treatment Options
Treatment options for acute limb ischemia include:
- Thrombolysis, which has been widely utilized and can be effective in restoring blood flow to the extremity 4
- Endovascular procedures, such as thromboaspiration, mechanical thrombectomy, and stent implantation, which can provide results at least as good as traditional surgical approaches 5, 6
- Surgical revascularization, including Fogarty thrombembolectomy, bypass, endarterectomy, patch angioplasty, or combinations, which can be used to restore blood flow to the extremity 6
- Pharmacological therapy, such as thrombolysis, which can be used to dissolve blood clots and restore blood flow to the extremity 6
Patient Selection
Patient selection for thrombolysis versus open surgery is a clinical challenge, and the decision should be based on individual patient factors, such as the severity of symptoms, the status of collateral circulation, and the presence of comorbidities 4