Table 3.1.

Comparison of methods of noninvasive testing in patients with chronic limb-threatening ischemia (CLTI)

Techniques	Advantages	Limitations
AP or ABI	• Simple, inexpensive, quick, widely applicable • Provides data to predict wound healing and limb survival • Useful to monitor efficacy of therapeutic intervention	• Because of incompressible tibial arteries, may be falsely elevated or normal in patients with diabetes, renal insufficiency, or advanced age • Does not provide localization of the disease
TP or TBI	• Simple, inexpensive, quick • Useful in the presence of small-vessel artery disease • Useful in noncompressible tibial arteries • Provides data to predict wound healing and limb survival • Useful to monitor efficacy of therapeutic intervention	• Generally requires a hallux • Does not provide localization of the disease
Segmental pressures	• Useful in initial anatomic localization of CLTI disease • Useful in creating therapeutic plan based on disease localization • Provides data to predict wound healing and limb survival • Useful to monitor efficacy of therapeutic intervention	• Not accurate in noncompressible tibial arteries
TcPo2	• Useful to assess microcirculation • Can predict wound healing • May be useful for monitoring efficacy of revascularization	• Limited accuracy in the presence of edema or infection • Requires skin heating to ≥40°C • Time-consuming • Limited data validation
Skin perfusion pressure	• Useful to assess microcirculation and wound healing potential • May be useful for monitoring efficacy of revascularization • Can be measured in a shorter time compared with TcPo2	• Probe size and shape may affect measurements • Limited data validation

ABI, Ankle-brachial index; AP, ankle pressure; TBI, toe-brachial index; TcPo₂, transcutaneous oximetry; TP, toe pressure.

Adapted from Hirsch AT, Haskal ZJ, Hertzer NR, Bakal CW, Creager MA, Halperin JL, et al. ACC/AHA 2005 Practice Guidelines for the management of patients with peripheral arterial disease (lower extremity, renal, mesenteric, and abdominal aortic): a collaborative report from the American Association for Vascular Surgery/Society for Vascular Surgery, Society for Cardiovascular Angiography and Interventions, Society for Vascular Medicine and Biology, Society of Interventional Radiology, and the ACC/AHA Task Force on Practice Guidelines (Writing Committee to Develop Guidelines for the Management of Patients With Peripheral Arterial Disease): endorsed by the American Association of Cardiovascular and Pulmonary Rehabilitation; National Heart, Lung, and Blood Institute; Society for Vascular Nursing; TransAtlantic Inter-Society Consensus; and Vascular Disease Foundation. Circulation 2006;113:e463–654.