ABC | Volume 112, Nº6, June 2019

Statement Vascular Ultrasound Statement from the Department of Cardiovascular Imaging of the Brazilian Society of Cardiology – 2019 Arq Bras Cardiol. 2019; 112(6):809-849 Table 16 – Protocol for diagnostic examination and preoperative mapping Artery B-scan Pulsed Wave Doppler Color Imaging Normal Abnormal Normal Abnormal CFA Proximal SFA Mid SFA Distal SFA PA PTA ATA FA TFT Transverse: evaluate the diameter and aspect of the wall Longitudinal: evaluate the aspect of the wall and intraluminal diameter Transverse: measure the dilations and, if possible, the intraluminal stenosis Longitudinal: measure the lesion extent Longitudinal: use an angle ≤ 60 degrees, laminar flow, and multiphase curve (triphase) Longitudinal: evaluate the flow in the stenosis, and proximal and distal to the stenosis Use the peak systolic velocity in the site of highest velocity (V2), with angle ≤ 60 degrees, and 1 to 4 cm proximal to the lesion (V1) to calculate the velocity ratio (V2/V1) Flow in the post-stenotic segment: velocity turbulence or decrease Post-stenotic velocity curve of the parvus/tardus type indicates hemodynamic repercussion Assess vessel patency with intraluminal color filling Occlusion: lack of color filling Shows flow turbulence – mosaic aspect (aliasing) Guide the volume scan of the sample to detect the point of highest velocity FA: fibular artery; CFA: common femoral artery; DFA: deep femoral artery; SFA: superficial femoral artery; PA: popliteal artery; ATA: anterior tibial artery; PTA: posterior tibial artery; TFT: tibial-fibular trunk. Table 17 – Classification of the degree of stenosis in native arteries with pulsed wave Doppler Classification Systolic velocity ratio Stenosis < 50% V2/V1 < 2.0 Stenosis ≥ 50% V2/V1 ≥ 2.0 Stenosis ≥ 70% V2/V1 ≥ 4.0 Occlusion Lack of flow Aneurysm: report the identification and location of the aneurysm. Measure the largest diameter including the adventitial layer (out-out) with two-dimensional image in transverse plane. Investigate and document the presence of intraluminal thrombus with color flow imaging. Pseudoaneurysm: characterized by dilation that does not compromise all arterial layers and having a connecting channel with the arterial lumen. Evaluate all of these structures with two-dimensional image and color imaging, measuring the calibers. Use spectral Doppler in the connecting channel, where the typical “to-and-fro” flow can be found (Table 18). Therapeutic interventions should use color imaging and pulsed wave Doppler as a guide, evaluating blood flow in the native artery, aiding in the puncture – in cases of thrombin treatment –, and verifying the thrombosis of the pseudoaneurysm in all treatment modalities. 63 Table 18 presents the different patterns of arterial flow, with their names, clinical meanings, and main occurrence situations. 4.4. Essential Information to Include in the Medical Report • Report if there were technical difficulties during the examination. • Wall aspect and diameter of all arteries studied, when necessary. • Presence, aspect, location, and degree of stenosis of atherosclerotic plaques. • Stenosis velocity and characteristics of velocity curves in the post-stenotic segment. • Signs of segmental or complete arterial occlusion. 4.5. General Limitations of the Peripheral Artery Ultrasound • Examiner-dependent. • Equipment of low technical quality. • Lower-limb edema. • Unhealed ulcer. 5. Arteriovenous Fistulas for Hemodialysis 5.1. Introduction AVFs can be congenital, traumatic, or specifically created for hemodialysis. This guideline will cover only the technical aspects of VUS evaluation of AVF for hemodialysis (AVFH), which can be of two types: 1. Autogenous – radiocephalic or brachiocephalic (Brescia- Cimino) fistula. Figure 12 shows the latero-lateral connection between artery and vein in A; the terminal connection between the artery and lateral of the vein in B; the terminal connection between the vein and lateral of the artery in C; and the termino-terminal connection between artery and vein in D. 72 2. Polytetrafluorethylene (PTFE) grafts. Figure 13 shows an example of a straight PTFE graft between the basilic vein and 829