Management of Monophasic Left Popliteal Waveform

Diagnostic Approach

• The American College of Cardiology recommends urgent vascular imaging (ultrasound, CTA, or MRA) to exclude popliteal artery aneurysm, thrombosis, or significant proximal stenosis in patients with an isolated monophasic waveform in the left popliteal artery, as this represents hemodynamically significant arterial disease 1, 2, 3
• Ultrasound imaging is the most rapid means to confirm or exclude a popliteal aneurysm, which commonly presents with thromboembolism rather than rupture 1, 3
• Approximately 50% of popliteal aneurysms are bilateral, so checking for a prominent popliteal pulse in the contralateral leg is a diagnostic clue 1, 4, 3

Diagnostic Criteria

• Popliteal aneurysms ≥2.0 cm in diameter require surgical repair to prevent thromboembolic complications and limb loss 2, 3
• Up to 50% of asymptomatic popliteal aneurysms become symptomatic within 2 years and 75% within 5 years 1, 4, 3
• The American College of Cardiology recommends measuring resting ABI on both legs; an ABI ≤0.90 is abnormal and confirms PAD 5, 6

Management

• If popliteal aneurysm ≥2.0 cm is identified, proceed with elective surgical repair even if asymptomatic, as the risk of thromboembolic complications is 36-70% over 5-10 years of observation 1, 2, 4, 3
• Saphenous vein bypass provides superior long-term patency and limb salvage rates compared to prosthetic grafts 3
• If acute thrombosis with absent runoff, perform catheter-directed thrombolysis or mechanical thrombectomy first to restore distal vessels, then definitive bypass 2, 3

Risk Assessment

• Thrombosed popliteal aneurysms account for approximately 10% of acute arterial occlusions in elderly men and are commonly mistaken for embolic events 1
• The absence of triphasic waveforms does not exclude PAD, but their presence (ABI 0.9-1.3 with triphasic pedal waveforms) largely excludes significant disease 7, 8, 5