Morales Marcia M, Anacleto Alexandre, Filho Clewis Munhoz, Ledesma Sergio, Aldrovani Marcela, Wolosker Nelson
INVASE - Hospital Beneficência Portuguesa de São José do Rio Preto, Vascular Surgery, São José do Rio Preto, SP, Brazil.
INVASE - Hospital Beneficência Portuguesa de São José do Rio Preto, Vascular Surgery, São José do Rio Preto, SP, Brazil.
Ann Vasc Surg. 2019 Aug;59:1-4. doi: 10.1016/j.avsg.2018.12.086. Epub 2019 Feb 22.
Duplex ultrasonography (DUS), although consolidated as the primary tool for the estimation of carotid stenosis, may be impaired by calcified plaques that promote acoustic shadow (AcS). AcS seems to hamper the quantification of the main parameter used in the determination of percentage stenosis, that is, the maximal peak systolic velocity (PSV) at the lesion site. The aim of our study was to compare the degrees of carotid artery stenosis in DUS/PSV and computed tomography angiography (CTA) in the presence of AcS.
During 36 months, 1,178 carotid DUS tests were performed. A total of 164 carotids in 139 patients showed AcS resulting from calcified plaques. Carotids with AcS were referred for a second imaging examination; thus, 62 carotids were analyzed by both DUS/PSV and CTA. CTA measured the area reduction at the lesion site to calculate the percent stenosis. PSV was measured immediately after the end of the AcS. According to velocities-based DUS criteria, stenoses were classified as mild (PSV < 125 cm/s), moderate (125 ≤ PSV ≤ 230 cm/s), and severe (PSV > 230). CTA and DUS/PSV measurements were compared to determine the accuracy of PSV in characterizing the severity of carotid stenosis with AcS.
Of the 62 lesions, PSV characterized 10 as severe, 21 as moderate, and 31 as mild. According to the CTA study, there were 36 severe, 8 moderate, and 18 mild lesions. PSV underestimated in 27.79% the incidence of cases of severe carotid artery stenosis detected by the CTA. In addition, PSV overestimated the incidence of the cases of moderate and mild stenosis in 61.91% and 37.78%, respectively. The agreement ratio between the imaging examinations used in this study was 50%. DUS/PSV discretely correlated with CTA (r = 0.668, P < 0.0001, 95% confidence interval = 0.502-0.786). Using PSVs >125 and >230 as predictors of carotid lesions higher than 50% and 70%, respectively, the sensitivities were 63.3% and 27.8%, the specificities were 100%, the positive predictive values were 100%, and the negative predictive values were 71.9% and 50%.
PSV alone is inadequate to quantify carotid stenosis in the presence of calcified plaques and AcS. Another image tool, such as CTA, could be recommendable for clinical decision-making.
双功超声检查（DUS）虽已成为评估颈动脉狭窄的主要工具，但可能会受到导致声影（AcS）的钙化斑块的影响。声影似乎会妨碍用于确定狭窄百分比的主要参数的量化，即病变部位的最大收缩期峰值速度（PSV）。我们研究的目的是比较存在声影时DUS/PSV和计算机断层血管造影（CTA）评估的颈动脉狭窄程度。
在36个月期间，共进行了1178次颈动脉DUS检查。139例患者的164条颈动脉显示有钙化斑块导致的声影。有声影的颈动脉被转诊进行第二次影像学检查；因此，对62条颈动脉进行了DUS/PSV和CTA分析。CTA测量病变部位的面积缩小以计算狭窄百分比。在声影结束后立即测量PSV。根据基于速度的DUS标准，狭窄分为轻度（PSV < 125 cm/s）、中度（125≤PSV≤230 cm/s）和重度（PSV > 230）。比较CTA和DUS/PSV测量结果，以确定PSV在表征有声影的颈动脉狭窄严重程度方面的准确性。
在62个病变中，PSV将10个表征为重度，21个表征为中度，31个表征为轻度。根据CTA研究，有36个重度、8个中度和18个轻度病变。PSV低估了CTA检测到的重度颈动脉狭窄病例发生率的27.79%。此外，PSV分别高估了中度和轻度狭窄病例发生率的61.91%和37.78%。本研究中使用的影像学检查之间的一致率为50%。DUS/PSV与CTA存在离散相关性（r = 0.668，P < 0.0001，95%置信区间 = 0.502 - 0.786）。分别使用PSV>125和>230作为颈动脉病变高于50%和70%的预测指标，敏感性分别为63.3%和27.8%，特异性为100%，阳性预测值为100%，阴性预测值为71.9%和50%。
单独使用PSV不足以量化存在钙化斑块和声影时的颈动脉狭窄。对于临床决策，推荐使用另一种影像工具，如CTA。
