Catheter‑Directed Thrombolysis for Acute Femoral‑Popliteal Bypass Graft Occlusion

Indications & Patient Selection

Contraindications

Immediate Anticoagulation Protocol

Thrombolytic Regimens

Administration Technique

Mechanical Adjuncts

Post‑Thrombolysis Management

Decision Algorithm: When to Choose Surgery

Pitfalls to Avoid

Expected Outcomes

Acute Limb Ischemia Management

Immediate Actions

• The American College of Cardiology recommends immediate administration of systemic anticoagulation with unfractionated heparin unless contraindicated, to prevent thrombus propagation and provide anti-inflammatory effects that lessen ischemia 7, 8
• Assess limb viability using the Rutherford classification to determine urgency of intervention, and evaluate the "6 Ps": Pain, Pulselessness, Pallor, Poikilothermia, Paresthesias, and Paralysis 7, 8, 9
• Use handheld continuous-wave Doppler to assess arterial and venous signals, as pulse palpation alone is inaccurate, and loss of dopplerable arterial signal indicates the limb is threatened 7
• Contact a vascular specialist immediately for emergent evaluation, and consider immediate transfer to a facility with vascular intervention capabilities if local expertise is unavailable 7, 8

Diagnostic Imaging

• Obtain CT angiography of the entire lower extremity as the preferred initial imaging modality, which provides rapid, comprehensive anatomic detail including the level of occlusion, degree of atherosclerotic disease, and below-knee vessel patency 9, 10
• Patients with Category IIb or Category III may require immediate surgical intervention even before imaging, as presence of paralysis or motor weakness beyond the toes indicates need for urgent revascularization within 1-2 hours 7, 9, 10

Critical Time Constraints

• Skeletal muscle tolerates ischemia for approximately 4-6 hours before irreversible damage occurs, and delays beyond 6 hours dramatically increase risk of permanent tissue damage, amputation, and death 7, 8, 9, 10

Revascularization Planning

• For Category IIb limbs, proceed directly to revascularization within hours, and open surgical thromboembolectomy is often more time-effective than catheter-directed thrombolysis when motor deficits are present 7, 8, 10
• The revascularization strategy should be determined by local resources, patient factors, etiology of occlusion, and degree of ischemia, and both endovascular and surgical approaches have similar 1-year outcomes when appropriately selected 7, 9

Common Pitfalls to Avoid

• Do not delay vascular consultation or anticoagulation to obtain imaging studies, and do not rely on ankle-brachial index (ABI) for diagnosis, as it only confirms occlusion but provides no information about location, cause, or treatment planning 7, 9, 10
• Do not attempt revascularization in Category III limbs, as reperfusion can cause multiorgan failure from ischemic metabolite circulation 7, 10

Special Consideration for Coronary Artery Disease

• Optimize cardiac status while preparing for intervention, but do not delay limb-saving therapy, as the combination of CAD and acute limb ischemia is associated with increased all-cause mortality 7, 9