Parâmetros diretos do duplex scan no diagnóstico da estenose da artéria renal: estudo de validação e otimização dos pontos de corte

Abstract

OBJECTIVETo test the efficiency of the direct duplex scanning parameters in the diagnosis of renal artery stenosis (RAS), and verify whether or not the cut-off points recommended by medical literature are the most appropriate means to distinguish lesion severity. METHODSProspective study, including 62 patients with RAS, submitted to a duplex ultrasound scan and selective arteriography. The peak systolic velocity (PSV) and the renal-aortic ratio (RAR) were measured. Statistical analysis included the ROC (receiver operating characteristic curve), unpaired student's t-test, sensitivity, specificity, positive and negative predictive values and accuracy. RESULTSThe arteriography revealed RAS 0-59% in 31 arteries (24%); RAS 60-99% in 91 arteries (72%) and 5 occlusions (4%). ROC analysis demonstrated that the lesion detection efficiency of PSV and RAR were similar with areas below the curves of 0.96 and 0.95, respectively. Considering the cut-off points recommended by medical literature, PSV of 180 cm/sec presented a sensitivity of 100% and specificity of 81%, while the RAR of 3.5 presented a sensitivity of only 79%, with a specificity of 93%. These parameters were analyzed in conjunction (direct criteria) revealing a sensitivity of 79% and specificity of 97%. The optimized cut-off points were: PSV of 189 cm/sec and RAR of 2.6, demonstrating sensitivity and specificity rates of 100%, 87%, 96% and 87% respectively.

Accuracy of Duplex Ultrasound for Detecting Renal Artery Stenosis: A Systematic Review

“…Most studies reported sensitivity (n = 24/25) 3,5,12,14,24-29,30-39,40-43 and specificity (n = 24/25). 3,5,12,14,24-29,30-39,40,41,43,44 Nine of 24 studies reported exclusively high sensitivity (range: 90%-100%) 29,33,34,37,38,40,41,45 and 13 of 25 reported high specificity (range: 81%-100%). 3,14,24,29-31,33,34,37,38,40,…”

“…Twelve of 25 studies reported accuracy as a main outcome. 12,14,[24][25][26][27][28][29][30][31]32,33 Six of those 12 studies reported high agreement with CVA, 14,30,33 SRA, 25,29 and MRA 24 (range: 81-98%). The remaining 6 of 12 studies reported either moderate, 28 low, 31 or a combination of the degree of agreement depending on the DUS parameter.…”

“…12,27,32 These studies were generally conducted using similar criterion measures (eg, MRA, SRA, and CVA). Most studies reported sensitivity (n = 24/25) 3,5,12,14,[24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43] and specificity (n = 24/25). 3,5,12,14,[24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39]40,41,43,44 Nine of 24 studies reported exclusively high sensitivity (range: 90%-...…”

“…Eighteen studies reported PPV and/or NPV. 3,5,12,[24][25][26][27][28][29][30][31][32][33][34][35][39][40][41] Five of 18 studies reported high PPV (range: 83%-100%) 24,29,30,33,45 and 9 of 18 studies reported high NPV (range: 83%-97%). 3,24,26,29,30,[33][34][35]41 Six of 18 studies reported moderate (range: 60%-76%) 3,28,31,41 and low PPV (range: 55%-57%) 34,39 and 2 of 18 reported moderate (67%) 39 and low (50%) NPV.…”

Analysis of peripheral artery velocity tracing in a porcine model

“…Therefore, hemodynamics can be monitored with ultrasound through the velocity tracing. Apart from pulsatility index (PI) and resistant index (RI)15–18, peak systolic velocity (PSV) and ratio of PSV at stenosis to PSV at proximal artery are generally regarded as the important indexes in predicting stenosis and its severity 19–24. However, the valve of velocity is related to many factors such as the site of sampling and the correction angle.…”