Prevalence of Tibial Artery and Pedal Arch Patency by Angiography in Patients With Critical Limb Ischemia and Noncompressible Ankle Brachial Index.

BACKGROUND: Approximately 20% of patients undergoing ankle brachial index testing for critical limb ischemia have noncompressible vessels because of tibial artery calcification. This represents a clinical challenge in determining tibial artery patency. We sought to identify the prevalence of tibial artery and pedal arch patency by angiography in these patients. METHODS AND
RESULTS: One hundred twenty-five limbs (of 89 patients) with critical limb ischemia and ankle brachial index ≥1.4 who underwent lower extremity angiograms within 1 year were included. Reviewers of angiography were blinded to results of physiological testing. Tibial artery vessels were classified as completely occluded, significantly stenosed (≥50%), or patent (<50% stenosis). The sensitivity of toe brachial index and pulse volume recording to predict tibial artery disease was also determined. Of 125 limbs with noncompressible ankle brachial index, 72 (57.6%) anterior tibial and 80 (64%) posterior tibial arteries were occluded. Another 23 (18.4%) anterior tibial and 13 (10.4%) posterior tibial arteries had ≥50% stenosis. Pulse volume recording was moderate to severely dampened in 54 of 119 (45.4%) limbs. Toe brachial index <0.7 was found in 75 of 83 (90.4%) limbs. Moderate to severe pulse volume recording dampening was 43.6% sensitive, whereas toe brachial index <0.7 was 89.7% sensitive in diagnosing occluded or significantly stenotic tibial artery disease. The pedal arch was absent or incomplete in 86 of 103 (83.5%) limbs.
CONCLUSIONS: Among patients with critical limb ischemia and noncompressible ankle brachial index results, the prevalence of occlusive tibial and pedal arch disease is very high. Toe brachial index <0.7 is more sensitive in diagnosing occluded and significantly stenotic tibial artery disease in these patients compared with ankle pulse volume recording.