What is the management approach for a heel ulcer in a patient without detectable pulses, likely indicating Peripheral Artery Disease (PAD)?

Work-up for Heel Ulcer Without Detectable Pulses

A heel ulcer with absent pedal pulses requires immediate objective vascular assessment with ankle-brachial index (ABI), toe-brachial index (TBI), and pedal Doppler waveform analysis, as absent pulses alone are insufficient to confirm or exclude significant peripheral artery disease (PAD). 1

Initial Bedside Vascular Assessment

Perform the following non-invasive tests immediately:

• Ankle-Brachial Index (ABI): Measure bilateral ankle systolic pressures and calculate ABI; values <0.9 indicate PAD 1, 2

  • Critical caveat: ABI may be falsely elevated (≥1.3) due to arterial calcification from medial wall sclerosis (Mönckeberg sclerosis), particularly in diabetic patients, rendering the test unreliable 1

• Toe-Brachial Index (TBI): If ABI is >1.3 or unreliable, measure TBI; values <0.75 suggest significant PAD 1, 2

• Pedal Doppler Arterial Waveforms: Assess waveform patterns with handheld Doppler; absence of triphasic waveforms strongly suggests PAD even when other measurements are ambiguous 1, 3

• Toe Pressure or Transcutaneous Oxygen Pressure (TcPO₂): Consider these measurements as ABI can be falsely elevated; toe pressure provides more reliable assessment in calcified vessels 1

Clinical Examination Beyond Pulse Palpation

Look for these specific PAD indicators:

• Cool lower limb temperature compared to contralateral side 1
• Femoral bruits on auscultation 1
• Prolonged venous filling time (>20 seconds) 1
• Ulcer location: heel ulcers are more commonly ischemic or neuro-ischemic rather than purely neuropathic 1

Advanced Vascular Imaging Indications

Proceed to vascular imaging if any of the following are present:

• ABI <0.5 or ankle pressure <50 mmHg 2
• Non-healing ulcer despite optimal wound care 1, 4
• Absent or monophasic Doppler waveforms 1
• TcPO₂ <30 mmHg at perilesional area 5

Imaging modality selection: Arrange CT angiography, MR angiography, or conventional angiography to define arterial anatomy for revascularization planning 1, 4

Critical Management Priorities

Up to 50% of patients with foot ulcers have coexisting PAD, and these patients face significantly increased risk of amputation and mortality. 1, 2

Immediate Actions:

• Offload the heel completely: Non-weight bearing is essential; use appropriate devices to eliminate pressure 1, 6

• Assess for infection and osteomyelitis: Deep heel infections require urgent surgical debridement 7, 8

• Do NOT debride ischemic heel ulcers without infection: Unlike neuropathic ulcers, ischemic ulcers should not undergo aggressive debridement unless infected 1

Revascularization Considerations:

Revascularization should be strongly considered when:

• Ankle pressure <50 mmHg or ABI <0.5 2, 4
• Patent posterior tibial artery to the ankle is critical for heel perfusion (angiosome concept) 4, 5
• Healing may require up to 6 months post-revascularization; short-term graft patency alone is insufficient 4

Revascularization may be inappropriate when:

• Patient is severely frail, bed-bound, or has short life expectancy 1
• Large volume of tissue necrosis renders foot functionally unsalvageable 1
• Risk-benefit ratio is unfavorable due to severe comorbidities 1

Cardiovascular Risk Management:

All patients with ischemic heel ulcers require aggressive cardiovascular risk reduction:

• Smoking cessation support 1, 2
• Statin therapy 1, 2
• Low-dose aspirin or clopidogrel 1, 2
• Blood pressure control 1, 2
• Glycemic control in diabetic patients 1, 2

This reduces 5-year mortality from 58% to 36% in patients with neuro-ischemic foot ulcers. 1

Common Pitfalls to Avoid

• Never assume PAD is absent based solely on palpable pulses: Even skilled examiners can detect pulses despite significant ischemia 1, 2

• Never rely on ABI alone in diabetic patients: Arterial calcification causes falsely elevated readings; always obtain TBI or waveform analysis 1

• Never delay vascular assessment: Clinical examination sensitivity is too low to rule out PAD; objective testing is mandatory in all heel ulcers 1

• Never forget the posterior tibial artery: The heel's blood supply depends primarily on the posterior tibial artery; ensure this vessel is patent or revascularized 4, 5

Prognosis Factors

Poor healing predictors include:

• Impaired renal function (creatinine >1.5 mg/dL or dialysis dependence) 4, 8
• Serum albumin <3 g/dL 8
• Presence of gangrene 8
• Occluded bypass graft 4

Favorable healing predictors include:

• Normal renal function 4
• Palpable pedal pulse post-revascularization 4
• Patent posterior tibial artery past the ankle 4
• Multiple patent tibial arteries after bypass 4