Acute Limb Ischemia: The Role of Duplex and Rutherford Categories
Clinical Assessment and the Role of the Specialist
According to ESVS 2020 (Recommendation 3, Class I, Level Consensus), in suspected acute limb ischemia, clinical assessment must be performed urgently by a vascular specialist, who is responsible for planning further examination and treatment.
Rutherford Classification in Acute Ischemia
ESVS 2020 (Recommendation 4, Class I) recommends using the Rutherford classification for acute limb ischemia (Rutherford et al., 1997) during clinical assessment. Historically, Rutherford categories (Rutherford, 0–6) have been used in English-speaking practice alongside the Fontaine classification, based on clinical and non-invasive tests.
Both systems have revealed a common shortcoming over time: the term “critical limb ischemia” implied rigid perfusion thresholds, whereas the real threat to the limb is a continuum, depending not only on pressure but also on wound and infection. Therefore, the Global Vascular Guidelines (2019) introduced and recommended the term chronic limb-threatening ischemia (CLTI), preferred over “critical ischemia”. [note: detailed categories 0–6 of Rutherford are not provided in the fragments]
The Role of Duplex Scanning
ESVS 2020 provides a summary of imaging methods for acute limb ischemia (Table 3), comparing them in terms of availability, accuracy, invasiveness, therapeutic potential, and the ability to assess the entire vascular tree and adjacent structures. [note: specific values of the table are not provided in the fragments]
Duplex scanning is used for diagnosing peripheral arterial emboli and characterizing velocities in tibial arteries in severe peripheral atherosclerosis (data cited in AIUM 2025 Revision: Crawford JD et al., J Vasc Surg 2016). Duplex is a primary detection and monitoring method, but it is limited in distal segments and lacks standardized percentage criteria for several conditions.
Principles of Assessing Ischemia Severity
Identifying stenosis is only half the task; the physician and surgeon need to understand how severe the ischemia is and whether the limb is at risk of loss (Blagodir B.V., 2026). Severity assessment relies on ABI/TBI, classifications, and pedal acceleration time (PAT). The degree of stenosis is assessed by spectrum (not in B-mode), using PSV ratio, phasicity, and gradations based on the principle “FLOW = FLOW = FLOW”.
Frequently asked questions
Which classification is recommended for acute limb ischemia?
ESVS 2020 (Class I) recommends the Rutherford classification for acute limb ischemia (Rutherford et al., 1997) during clinical assessment.
Who should perform the initial assessment in suspected ALI?
According to ESVS 2020 (Class I, Level Consensus), clinical assessment is urgently performed by a vascular specialist, who is responsible for planning examination and treatment.
Can duplex be used for diagnosing arterial emboli?
Yes, duplex is used for diagnosing peripheral arterial emboli (Crawford JD et al., J Vasc Surg 2016, cited in AIUM 2025).
Why was the term 'critical ischemia' replaced with CLTI?
“Critical ischemia” implied rigid perfusion thresholds, whereas the threat to the limb is a continuum, also depending on wound and infection. Global Vascular Guidelines (2019) introduced the preferred term CLTI.
What are the limitations of duplex in ischemia assessment?
Duplex is limited in distal and intracranial segments and lacks standardized percentage criteria for several conditions; confirmation is conducted with radiological methods.