Doppler ultrasound for post-angioplasty follow-up in pediatric segmental branch renal artery stenosis: A case report

IntroductionSegmental branch renal artery stenosis is an important cause of renovascular hypertension in the pediatric population that is often managed with angioplasty and may require imaging multiple times pre- and post-procedure. Gold standard imaging is angiography, which exposes children to radiation and intravenous contrast. There is not a clear guideline for imaging during follow-up, but patients are monitored for symptom recurrence, which could then trigger repeat imaging. The following case highlights a method of follow-up that has not been broadly studied that may offer benefits over clinical monitoring alone, and how interprofessional cooperation could offer effective surveillance and reassurance for families through a cost-effective method that minimizes potential for harm.Case and outcomesThis report describes the clinical course of a child with hypertension secondary to segmental branch renal artery stenosis who was treated with angioplasty and who received follow-up imaging with renal Doppler ultrasound. This method allows the care team to ensure stability of the caliber of the repaired vessel and non-recurrence of stenosis at follow-ups through monitoring for intra-arterial velocity and waveform changes.DiscussionClose follow-up of children with renal artery stenosis is vital following intervention due to high risk of recurrence. Clinical follow-up alone could be sufficient for some patients, however many still require CTA, sometimes even more than once, when symptoms worsen or there is evidence of end-organ damage. During follow-up, collaboration with skilled sonographers to monitor post-repair velocities and waveforms using Doppler ultrasound presents several possible advantages. This includes providing reassurance to patient families, minimizing harmful radiation and contrast exposure, and the potential for early detection of recurrence of stenosis. Especially in cooperative, older pediatric patients with a normal BMI who have a main renal artery stenosis or even in those with a segmental branch stenosis identified through CTA such as in this case.ConclusionThis case demonstrates how coordination with sonographers and the use of ultrasound with Doppler could improve the follow-up of pediatric patients with segmental branch renal artery stenosis post-angioplasty to provide further reassurance to families, minimize harm to patients, and ensure post-procedure stability beyond just clinical parameters.     

Renovascular hypertension: can we identify a population at high risk?

Renovascular hypertension is a common cause of secondary hypertension. However, diagnostic tests are limited by lack of sensitivity and specificity, cost, or invasiveness. Selecting patients with hypertension for evaluation of renal artery stenosis can be challenging. This review focuses on the sensitivity and specificity of commonly used screening tests for renal artery stenosis and on the clinical variables that are most likely to distinguish patients with renal artery stenosis from patients with other causes of their hypertension. This approach allows for the rational screening of patients at high and moderate risk for renal artery disease.     

Renal artery stenosis: value of contrast-enhanced ultrasonography

Renal artery stenosis is the most common cause of potentially curable secondary hypertension. For a long time, angiography has been considered the gold standard in screening for renal arterial occlusive disease, but it is expensive and invasive. Magnetic resonance angiography and spiral computed tomography are safer alternatives to angiography but are expensive and not widely available. Due to the fact that duplex scanning is noninvasive, it has been advocated since the early 1980s as a screening test for renal vascular disorders. Factors that make duplex ultrasound an attractive screening measure for renovascular disease are its safety, suitability for outpatient use, and low cost. However, the frequency of artery variants, lengthy examination time, and technically inadequate test conditions limit the use of the direct duplex ultrasound detection of renal artery stenosis. Advances in Doppler technology may alleviate some of the current problems related to examination of renal arteries. One such technique is the use of echo-enhancing agents, which increase Doppler signal strength and can improve the sensitivity and specificity in Doppler ultrasound detection of renal artery stenosis.     

能量多普勒显像与彩色多普勒显像诊断13 例肾动脉狭窄意义的探讨

目的 研究能量多普勒显像（ＰＤＩ）在中型动脉的显示效果。探讨超声无创性诊断肾动脉狭窄的可能性。方法 使用彩色多普勒血流显像（ＣＤＦＩ）、能量多普勒显像及脉冲多普勒频谱分析（ＰＷＤ）对经血管造影证实的１３例肾动脉狭窄病人进行研究。结果 ＰＤＩ能够更好地反映狭窄血管的真实形态,明显增加肾动脉的显示长度和血流的稳定性。减少检查时间。结论 结合使用ＰＷＤ及其他超声新技术,ＰＤＩ可以很好的用来筛选和诊断肾动     

Diagnostic imaging evaluation of renovascular hypertension

Over 50 million people in the United States are hypertensive. Renovascular disease accounts for 3–5% of these hypertensive patients. Because renovascular hypertension is potentially curable, much effort has been devoted to detecting and treating renal artery stenosis. Conventional angiography has been traditionally used to diagnose renal artery stenosis. However, because of its invasiveness and cost, conventional angiography cannot be utilized as a screening test in all patients who may have renal artery stenosis. Several noninvasive studies have been advocated for screening in hypertensive patients who may have renovascular disease. However, the accuracy of these noninvasive studies is widely variable, and appropriate use of these noninvasive studies needs to be better defined. Appropriate use of diagnostic imaging examinations for hypertensive patients depends on the index of suspicion for renovascular disease and on the patient's renal function. If certain clinical findings suggest the possibility of renovascular disease, then conventional angiography/intraarterial digital subtraction angiography should be performed. Captopril renography or duplex Doppler sonography could also be utilized if angiography is not desired or is contraindicated because of impaired renal function or a contrast allergy. Magnetic resonance angiography appears to be most helpful in a small, select group of patients who are likely to have proximal renal artery stenosis.     

Clinical characteristics useful in screening for renovascular disease

In an effort to detect renovascular hypertension, clinical characteristics are used to select patients likely to have renal artery stenosis. We prospectively evaluated the ability of commonly used clinical features to predict the presence of renal artery stenosis in 100 hypertensive adults. All subjects had conventional renal arteriography. Renal artery stenosis was diagnosed if there was 50% or more stenosis of a main renal artery. Eighteen of the 100 had renal artery stenosis. The presence of a bruit was strongly associated with renal artery stenosis (P less than .0005). In patients without a bruit, only refractory hypertension was associated with the presence of renal artery stenosis (P = .051). These data suggest that a bruit and refractory hypertension are associated with renal artery stenosis, but that other clinical features investigated may not be and that other means of screening for renovascular disease are needed.     

彩色多普勒超声诊断肾动脉粥样硬化性狭窄

目的探讨彩色多普勒超声诊断肾动脉粥样硬化性狭窄的价值。方法61例患者共122支肾动脉同时行彩色多普勒超声及血管造影。结果彩色多普勒超声诊断肾动脉狭窄的敏感性为90％,特异性为96％;诊断显著狭窄的敏感性为86％,特异性为99％;诊断＜50％狭窄的敏感性为82％,特异性为96％;诊断狭窄位置准确率为97％。结论肾动脉彩色多普勒超声对于肾动脉狭窄、初筛诊断以及评价肾动脉狭窄介入治疗的近、远期疗效,是一种非常理想的选择。     

无创性检查在肾动脉狭窄中的诊断价值

目的探讨无创性检查对肾动脉狭窄的诊断价值。方法回顾性研究临床上怀疑肾血管性高血压(RVH)的患者所进行核素检查、彩色多普勒超声、螺旋CT(CTA)、磁共振血管成像(MRA)与肾动脉造影结果。结果 67例病人中经腹主动脉-肾动脉造影确诊肾动脉狭窄34例,腹主动脉狭窄3例,正常者30例。肾血流图的敏感度约为67.4%,特异度为53.1%;肾动态显像的敏感度约为67.3%,特异度为36.6%;肾脏超声的敏感度约为30%,特异度在91.9%以上;肾动脉彩色多普勒超声的敏感度为58.8%,特异度为83.7%;CTA或MRA的诊断结果与造影相符。结论彩色多普勒超声和核素检查可用于肾动脉狭窄的初步筛查,如果异常,可根据患者的年龄及肾功能状况选择CTA或MRA。肾动脉狭窄程度及下一步治疗方法的选择仍需依靠肾动脉造影。     

能量多普勒显像与彩色多普勒显像诊断13 例肾动脉狭窄意义的探讨

目的 研究能量多普勒显像(PDI) 在中型动脉的显示效果,探讨超声无创性诊断肾动脉狭窄的可能性。 方法 使用彩色多普勒血流显像(CDFI) 、能量多普勒显像及脉冲多普勒频谱分析(PWD) 对经血管造影证实的13 例 肾动脉狭窄病人进行研究。结果 PDI 能够更好地反映狭窄血管的真实形态,明显增加肾动脉的显示长度和血流的 稳定性,减少检查时间。结论 结合使用PWD 及其他超声新技术,PDI 可以很好的用来筛选和诊断肾动脉狭窄。     

Neurofibromatosis, hypertension, and renal artery aneurysms

A case of bilateral renal artery stenosis and aneurysms in association with neurofibromatosis and hypertension is discussed and the literature is reviewed. In patients with neurofibromatosis and hypertension, the association of pheochromocytomas is well known. The association of renal of renal vascular lesions must also be recognized. In children with neurofibromatosis and hypertension, renal artery stenosis is far more common than pheochromocytoma. In adults aneurysms often accompany the renal artery stenosis. Laboratory studies, as well as most intravenous pyelograms, have been normal and, therefore, unreliable for screening. Angiography is essential in the investigation of hypertension in patients with neurofibromatosis.     

房间隔膨出瘤的超声诊断价值

目的 了解房间隔膨出瘤(IVSBA)的超声特征，评价超声诊断IVSBA的价值。方法全部患者应用二维彩色多普勒超声诊断仪进行检查，共检出IVSBA患者24例，另4例为正常人。结果 24例IVSBA患者中，右室流出道狭窄4例，肺动脉狭窄7例，室间隔缺损并肺动脉高压8例，高血压5例。19例患者已经手术证实。结论 IVSBA需早期诊断，追踪观察，为临床提供合适的治疗时机。     

Renovascular disease: Doppler ultrasound

Color Doppler ultrasound (CDUS) seems to be an effective imaging technique for the diagnosis of renal vascular diseases. It is already the modality of choice for the detection of acute renal vein thrombosis and nonocclusive intrarenal vascular disorders including iatrogenic arteriovenous fistula and false aneurysm, particularly in patients with impaired renal function that precludes the use of iodinated contrast agents. Although proximal Doppler interrogation remains an important step in diagnosing renal artery (RA) stenosis, useful hemodynamic information can be obtained from the distal arterial bed. When CDUS fails in identifying proximal RAs, normal waveform velocity and morphology obtained from intrarenal arteries enable one to rule out RA occlusion and most of the severe stenoses (≥80%). Such information, which is not subject to a significant risk of technical failure, seems to be particularly useful in studying patients with acute renal failure of suspected vascular origin. Despite the extreme variability in reported performance between studies, CDUS has seemed to be a valuable tool compared with other noninvasive modalities in the diagnosis of RA stenosis. Whereas a CDUS-based strategy is already accepted in numerous specialized centers, a thorough evaluation of diagnostic criteria and extensive training of operators will allow CDUS to be widely accepted for the screening of patients at high risk for renovascular hypertension.     

超声造影对移植肾肾动脉狭窄的实验研究

目的探讨超声造影技术在观察犬移植肾动脉主干不同狭窄程度的应用价值。方法将8例正常移植肾犬暴露移植肾动脉,取硅胶管套在移植肾动脉上,造成轻、中、重度及完全闭塞的动脉狭窄程度;游标卡尺、彩色多普勒及超声造影分别测量其狭窄程度。结果超声造影对不同狭窄程度的肾动脉管径的测值与游标卡尺测值比较,差异无统计学意义（P≥0．091）。移植肾动脉不同程度狭窄的造影改变各不相同。结论声学造影技术能够直观完整地显示移植肾动脉及移植肾内的血流分布,并可辅助分析移植肾的血流灌注状态。     

Noninvasive Doppler assessment of renal artery stenosis and hemodynamics

We present a review of ultrasonic Doppler methods (duplex scanning) used in the noninvasive assessment of renal artery stenosis and hemodynamics. The clinically successful applications of ultrasonic Doppler methods to the noninvasive assessment of the peripheral and cerebral vasculatures have prompted investigators to apply these methods to the renal artery. Various Doppler criteria for the diagnosis of renal artery stenosis have given sensitivities and specificities that range from 31% to 91% and 88% to 100%, respectively. Furthermore, estimates of renal vascular flows and resistances can be made in echogenic subjects. The technical success rate of the method is operator dependent, consequently, reliable duplex scanning of the renal arteries may be limited to experienced ultrasound laboratories.     

Doppler ultrasound and renal artery stenosis: An overview

Renovascular disease is a complex disorder, most commonly caused by fibromuscular dysplasia and atherosclerotic diseases. It can be found in one of three forms: asymptomatic renal artery stenosis (RAS), renovascular hypertension, and ischemic nephropathy. Particularly, the atherosclerotic form is a progressive disease that may lead to gradual and silent loss of renal function. Thus, early diagnosis of RAS is an important clinical objective since interventional therapy may improve or cure hypertension and preserve renal function. Screening for RAS is indicated in suspected renovascular hypertension or ischemic nephropathy, in order to identify patients in whom an endoluminal or surgical revascularization is advisable. Screening tests for RAS have improved considerably over the last decade. While captopril renography was widely used in the past, Doppler ultrasound (US) of the renal arteries (RAs), angio-CT, or magnetic resonance angiography (MRA) have replaced other modalities and they are now considered the screening tests of choice. An arteriogram is rarely needed for diagnostic purposes only. Color-Doppler US (CDUS) is a noninvasive, repeatable, relatively inexpensive diagnostic procedure which can accurately screen for renovascular diseases if performed by an expert. Moreover, the evaluation of the resistive index (RI) at Doppler US may be very useful in RAS affected patients for predicting the response to revascularization. However, when a discrepancy exists between clinical data and the results of Doppler US, additional tests are mandatory.     

肾动脉狭窄超声诊断的研究进展

超声诊断肾动脉狭窄（RAS）依据为主肾动脉狭窄与狭窄远端肾内动脉血流动力学改变,主肾动脉狭窄处主要指标有峰值血流速度流速加快、主肾动脉狭窄处与主动脉峰值速度之比值升高、主肾动脉收缩峰值加速时间延长等,肾内动脉主要指标有收缩期早期加速时间延长,收缩期早期加速度降低,主肾动脉血与肾内动脉流峰值速度之比增大等。超声造影可以改善了肾动脉的血流显像,提高RAS的诊断率。超声检查为诊断RAS提供了新的有效方法,应多种指标联合应用,并结合临床表现分析诊断RAS,提高RAS的诊断率。     

彩色多普勒超声检测颈部动脉227例的结果分析

目的:通过彩色多普勒超声检测颈部动脉结果分析探讨其临床诊断价值。材料与方法:利用彩色多普勒超声诊断仪对227例患者进行颈总动脉、颈内动脉、椎动脉检查,观察血管壁结构、有无斑块、斑块的大小、类型、管腔狭窄率及血管走行情况。结果:227例患者颈部血管B超检测异常率为84.58%,且与患者年龄增长呈正相关,与性别无明显性差异。颈动脉系统血管病变主要为颈动脉粥样硬化及颈动脉狭窄,而椎动脉则主要为走行迂曲或内径变细,二者的动脉损害是有一定差异的。结论:在临床对脑血管病进行病理生理诊断时,应常规做颈部血管彩色B超,除进行中风筛查外,并根据检查结果及早采取防治措施,尤其重视颈椎病的防治。     

彩色多普勒超声对动脉粥样硬化性肾动脉狭窄的诊断价值

目的评价彩色多普勒超声对动脉粥样硬化性肾动脉狭窄(ARAR)的诊断准确性,并确定其最有效的诊断方法。方法 86例ARAR患者,超声检测其172个肾脏形态学及172条肾动脉血流动力学指标:动脉狭窄处峰值血流速度(PSV)、肾动脉与腹主动脉峰值流速比值(RAR)及叶间动脉加速时间(AT);以肾动脉造影为标准,评价超声诊断ARAS的准确性。结果 172条肾动脉造影:肾动脉37条正常,36条狭窄60%,92条狭窄60%～95%,5条狭窄96%～99%,2条闭塞。超声诊断狭窄≥60%符合率为98.0%。对狭窄≥60%的病变,肾动脉PSV≥180 cm/s的敏感性95.9%,RAR≥3.0的敏感性56.7%,AT0.07 s的敏感性69.1%,肾脏长径的ROC曲线下面积为0.504。肾动脉狭窄96%～99%时,肾动脉PSV180 cm/s,而AT均0.07 s,患处血流较对侧明显变细。闭塞时,肾动脉主干内未见彩色血流信号,如肾内能显示动脉血流,AT0.07 s。结论对于诊断肾动脉狭窄60%～95%的ARAS,肾动脉PSV是最佳指标;对于高度狭窄及闭塞者,两侧动脉的彩色血流对比显示联合AT0.07 s,较单纯血流动力学指标更可靠。     

Renal artery PTA and stent implantation: immediate and late clinical and morphological outcome

BACKGROUND: Renal artery stenosis (RAS) is a potentially curable cause of secondary hypertension, but the indications for interventional treatment of renovascular hypertension are still a matter of debate. The aim of the study was to investigate immediate and long-term results of percutaneous renal artery revascularization (PTRA). Primary technical success, peri-intervention complications, patency, the course of arterial hypertension and renal function were analyzed. METHODS: 32 renal interventions in 24 consecutive patients (15 PTA, 17 stents) were investigated in a retrospective cohort study. Comorbidities, interventional data and serum creatinine were recorded. Patients were followed for a median period of 45 months (IQR, 32 to 68). Clinical evaluation of the course of blood pressure, serum creatinine, Doppler ultrasound evaluation and multi-slice spiral-CT angiography were performed at follow-up. RESULTS: Primary technical success was achieved in 30 interventions (94%), and in 2 patients during a secondary intervention. The rate of complications was 16% (n = 5). Three major complications were encountered (9%): 1 renal artery thrombosis and 2 acute renal failures. Three patients developed late renal failure after 1, 4 and 37 months, but the overall serum creatinine levels remained stable during the observation period. Hypertension was improved after intervention in 17 patients (71%). However, recurrent hypertension was found in 9 patients (38%) after a median period of 49 months (IQR, 47 to 96). Patency rates at 12, 24 and 72 months were 94%, 94% and 64%, respectively. CONCLUSION: Renal artery PTA can be performed with an acceptable rate of major complications and good long term morphological results. However, clinical outcome in terms of sustained improvement of hypertension is moderate.     

椎动脉狭窄性病变的超声诊断

目的探讨椎动脉狭窄性病变的超声表现及其诊断价值。方法回顾性分析55例经彩色多普勒超声检查并诊断为椎动脉狭窄患者的超声资料,根据超声声像图表现进行分型。结果55例患者根据其超声表现分为以下五型：椎动脉先天性发育细小型16例,内膜增厚型11例,斑块狭窄型20例,闭塞型7例,外源性压迫型1例。椎动脉狭窄性病变彩色多普勒超声有特异性表现。结论彩色多普勒超声对椎动脉狭窄性病变有较高诊断价值,并可为临床诊断提供准确资料。