Background: Peripheral arterial occlusive disease (PAOD) influences the mortality of patients on hemodialysis therapy. Although the ankle-brachial pressure index (ABI) is used widely to detect PAOD, it yields false-negative results because of calcifications of vascular walls. To more accurately assess the prevalence of PAOD, we investigated which noninvasive method, among ABI, toe-brachial pressure index, transcutaneous Po(2), and skin perfusion pressure (SPP), had superior sensitivity and specificity to the others.
Methods: Multidetector-row computed tomography was performed in 36 hemodialysis patients. We then compared the 4 noninvasive methods with findings of multidetector-row computed tomography and calculated the sensitivity and specificity of each method by means of receiver operating characteristic analysis. Irrespective of symptoms, PAOD is defined as the presence of complete obstruction in the case of lesions below the knee or more than 75% stenosis for lesions above the knee.
Results: Seven of 36 patients (19.4%) had an ABI less than 0.9. Sensitivity of the ABI was only 29.9%, whereas an SPP set at 50 mm Hg was more accurate, with sensitivity of 84.9% and specificity of 76.9%. A total of 41.4% of patients had an SPP less than 50 mm Hg. For lesions located above the knee, toe-brachial pressure index provided sensitivity of 91.7% and specificity of 86.7%.
Conclusion: SPP is the most useful tool for detecting PAOD in hemodialysis patients, with accuracy of 84.9%. There is a strong possibility that more patients than previously expected have early PAOD.