Effect of multilevel sequential stenosis on lower extremity arterial duplex scanning

Lower extremity arterial disease is commonly evaluated using duplex scanning. Prior research has shown that this technique is generally reliable for detecting significant stenoses. However, no prior work had resolved how well it performs in cases with multiple sequential stenoses. Established knowledge includes the use of peak systolic velocity as a key indicator of arterial narrowing. That uncertainty drove the need to compare duplex scanning results with arteriography in complex vascular anatomy. This gap motivated a study to clarify diagnostic accuracy in limbs with multiple stenotic segments. The goal was to determine whether the presence of multiple stenoses affects the reliability of duplex scanning. No prior work had resolved how sequential stenoses might influence diagnostic sensitivity. This paper's contribution is to address that specific uncertainty.

The aim of this investigation was to assess the impact of multilevel sequential stenosis on the diagnostic accuracy of lower extremity arterial duplex scanning. The specific problem addressed is the potential decrease in sensitivity when multiple stenoses are present in a single limb. The motivation stems from the need to improve diagnostic confidence in complex vascular anatomy. The study focused on comparing duplex scan results with arteriography in 80 extremities of 44 patients. The researchers sought to determine whether the presence of multiple stenoses affects detection rates. They categorized stenoses as first or second order based on their position in the arterial tree. The goal was to quantify diagnostic performance in both scenarios. This approach allowed for a direct comparison of sensitivity and specificity metrics.

The study compared duplex scanning results with arteriography in 80 lower extremities from 44 patients. The researchers analyzed specific arterial segments including the common femoral, upper and lower superficial femoral, above- and below-knee popliteal arteries, and tibioperoneal trunk. Stenoses were categorized as first order or second order based on their anatomical sequence. The team used standard duplex scanning protocols to detect stenoses exceeding 50% luminal narrowing. They calculated sensitivity, specificity, and positive predictive values for each arterial segment. Peak systolic velocity measurements were recorded at stenotic sites. The data were analyzed to compare diagnostic accuracy between first and second-order stenoses. This approach allowed for a detailed assessment of how sequential stenoses affect diagnostic outcomes.

Duplex scanning detected 18 of 23 first-order stenoses but only 1 of 8 second-order stenoses (P < 0.01). Sensitivity for first-order stenoses was 78% compared to just 13% for second-order stenoses. Peak systolic velocity was significantly higher in first-order stenoses (168 ± 54 cm/s) than in second-order stenoses (38 ± 13 cm/s, P < 0.00002). Sensitivity varied by arterial segment: 86% for the common femoral artery and 97% for the lower superficial femoral artery. Specificity was consistently high across all segments, reaching 98% in the upper superficial femoral artery. Positive predictive values ranged from 67% to 95%. The tibioperoneal trunk showed the lowest sensitivity at 25%. These findings suggest that sequential stenoses significantly reduce diagnostic accuracy in duplex scanning.

The authors propose that the presence of multilevel sequential stenosis reduces the sensitivity of lower extremity arterial duplex scanning. They suggest that second-order stenoses may be missed due to low peak systolic velocities. The study indicates that diagnostic accuracy is highest for first-order stenoses. The researchers propose that sequential stenoses alter hemodynamic patterns, affecting scan interpretation. They suggest that clinicians should be cautious when interpreting results in limbs with multiple stenoses. The findings may suggest the need for additional diagnostic tools in complex cases. The authors propose that peak systolic velocity is a key indicator of stenosis severity. They suggest that further research is needed to refine diagnostic protocols for multilevel disease.