When to Refer a Patient with Non-Healing Foot Wound to Vascular Surgery
Refer immediately to vascular surgery if the patient has an ankle pressure <50 mmHg or ankle-brachial index (ABI) <0.5, as these indicate severe ischemia requiring urgent revascularization. 1
Immediate/Urgent Referral Criteria (Within 24 Hours)
Patients with peripheral artery disease (PAD) and foot infection require emergency vascular evaluation and treatment within 24 hours, as they are at particularly high risk for major limb amputation. 1
Additional urgent referral indicators include:
- Toe pressure <30 mmHg 1
- Transcutaneous oxygen pressure (TcPO2) <25 mmHg 1
- ABI <0.5 or ankle pressure <50 mmHg 1
Early Referral Criteria (Consider Vascular Imaging)
Refer for vascular imaging and potential revascularization when the ulcer fails to show signs of healing after 6 weeks of optimal wound care, regardless of bedside perfusion test results. 1
Consider earlier referral if:
- ABI <0.6, which indicates significant ischemia that impairs wound healing potential 1
- Both foot pulses are absent on palpation 1
- Absent or monophasic Doppler signals from one or both foot arteries 1
Initial Bedside Assessment to Guide Referral Timing
Perform these tests at initial evaluation:
- Measure ABI (abnormal if <0.9) - this is the primary screening test 1
- Assess toe-brachial index (abnormal if <0.75) 1
- Evaluate pedal Doppler arterial waveforms (triphasic waveforms largely exclude PAD) 1
Interpreting Perfusion Tests for Healing Potential
Tests that predict reasonable healing potential (may allow 6-week trial of optimal wound care in patients without infection):
- Skin perfusion pressure ≥40 mmHg 1
- Toe pressure ≥30 mmHg 1
- TcPO2 ≥25 mmHg 1
- ABI >0.6 with toe pressure >55 mmHg or TcPO2 >50 mmHg 1
Critical Pitfalls to Avoid
Do not delay vascular referral while attempting wound care optimization in patients with severe ischemia (toe pressure <30 mmHg or TcPO2 <25 mmHg), as "time is tissue" in these cases. 1
Never assume diabetic microangiopathy is the cause of poor wound healing—PAD is the primary vascular cause requiring intervention. 1
Do not rely solely on symptoms or physical examination to exclude PAD, as these are unreliable predictors of healing in diabetic foot ulcers. 1 Always perform objective vascular testing with ABI and toe pressures. 1
Ensure vascular assessment occurs before contemplating major (above-ankle) amputation, as revascularization may still be possible even in severe cases. 1
Optimal Referral Pathway
The patient should be evaluated by an interdisciplinary care team that includes vascular surgery expertise, with both endovascular and surgical bypass capabilities available. 1 This coordinated approach achieves excellent limb salvage rates (80-85%) and ulcer healing (>60% at 12 months) when revascularization is performed. 1