What is the recommended treatment for a thrombosed popliteal arterial aneurysm?

Treatment of Thrombosed Popliteal Arterial Aneurysm

For thrombosed popliteal arterial aneurysms, the recommended treatment is initial catheter-directed thrombolysis or mechanical thrombectomy to restore distal runoff, followed by definitive surgical bypass with autologous saphenous vein graft. 1, 2

Initial Management

• Immediate administration of unfractionated heparin and appropriate analgesia upon diagnosis 2
• Urgent imaging with ultrasound to confirm the diagnosis - this is the most rapid means to confirm a thrombosed popliteal aneurysm 1, 2
• Check for a prominent popliteal pulse in the opposite leg, as approximately 50% of popliteal aneurysms are bilateral 2

Step 1: Restore Distal Runoff

• Catheter-directed thrombolysis or mechanical thrombectomy (or both) is strongly recommended to restore distal runoff and resolve emboli in patients with acute ischemia and absent runoff 1, 2
• Preoperative thrombolytic therapy has been shown to be a valuable adjunct for restoring runoff in the presence of recent thromboembolic events 1
• Studies show significantly better graft patency (p<0.005) and limb salvage (p<0.01) in patients who receive thrombolytic therapy compared to those who undergo emergency operations without prior thrombolysis 3
• Complete clearing of thrombus from runoff vessels can be achieved in most patients with thrombolytic therapy 3

Step 2: Definitive Treatment

• After restoration of runoff, surgical bypass is the standard treatment 2
• Bypass options include:
  • Saphenous vein grafts - provide superior long-term patency and limb salvage rates 1, 2
  • PTFE grafts - approximately twice as likely as polyester filament grafts to remain patent when autologous vein is unavailable 1, 2
• Consider fasciotomy in cases with prolonged ischemia to prevent compartment syndrome 2

Important Considerations

• Failure to attain runoff with catheter-directed thrombolysis suggests that atheroemboli are involved and/or that a fasciotomy should be considered due to high muscular compartment pressures 1
• Limb salvage rates correlate directly with the number of available runoff vessels, so clearing as much thrombus as possible from the tibioperoneal and plantar arteries is crucial 1
• Without proper treatment, up to 19% of patients with symptomatic popliteal aneurysms may require amputation despite surgical repair 2
• Early diagnosis and intervention are critical - amputation rates for untreated thrombosed popliteal aneurysms have been reported from 16% to 69% 4

Endovascular Options

• While endovascular stent-grafting has been used in selected cases of thrombosed popliteal aneurysms, there is limited evidence for its use in emergency settings compared to the well-established thrombolysis followed by surgical bypass approach 5

Prevention of Future Complications

• For asymptomatic popliteal aneurysms, repair is strongly recommended for aneurysms ≥2.0 cm in diameter to reduce thromboembolic complications and limb loss 1, 2
• Screen for other aneurysms, as approximately 50% of popliteal aneurysms are bilateral and 50% are associated with other aneurysms, particularly abdominal aortic aneurysms 2

The evidence strongly supports a two-step approach of thrombolysis to restore runoff followed by definitive surgical bypass, as this approach has demonstrated superior outcomes in terms of graft patency and limb salvage compared to emergency surgery alone 3, 6, 4.