Which PSV and EDV thresholds indicate flow-reducing stenosis in the superior mesenteric artery (SMA)?

• A. PSV > 260 cm/sec and EDV > 50 cm/sec
• B. PSV > 300 cm/sec and EDV > 60 cm/sec
• C. PSV > 275 cm/sec and EDV > 45 cm/sec
• D. PSV > 250 cm/sec and EDV > 40 cm/sec

Answer: (C)

When a lumen narrows in the superior mesenteric artery, blood must speed up to get through the tighter pass, so the peak systolic velocity rises. If diastolic forward flow remains appreciable (end-diastolic velocity is elevated) alongside that high systolic velocity, it indicates the stenosis is truly affecting flow over the whole cardiac cycle, not just a transient spike. The commonly cited duplex criteria for a hemodynamically significant SMA stenosis pair a peak systolic velocity of about 275 cm/s or greater with an end-diastolic velocity of about 45 cm/s or greater. This combination strongly suggests substantial narrowing (roughly 70% or more) and potential postprandial symptoms.

Other thresholds that deviate from this 275/45 pair are less consistently tied to clinically meaningful flow limitation, which is why the 275 cm/s and 45 cm/s values are the best choice.