Doppler ultrasound studies of subclavian steal hemodynamics in subclavian stenosis

By means of ultrasound Doppler sonography it is shown that a proximal subclavian stenosis does not necessarily influence the blood flow of the vertebral artery in a subclavian steal syndrome (permanent retrograde flow in the vertebral artery) as is characteristic for subclavian occlusion. Depending on the peripheral resistance in the cranial and brachial circulation, the vertebral artery competes with the brachial artery for the poststenotic flow. Thus, a reduction of the vertebral flow during hyperemia within the brachial artery ststem, alternating vertebral flow, or a temporary steal syndrome may result in stenosis. Obviously the relation of the flow resistance may also change within one pulse beat, so that in the vertebral artery a characteristic flow pulse, i.e., an alternating flow, is detected with opposite direction in systole and diastole.     

臂踝指数检测对锁骨下动脉重度狭窄的诊断价值

目的探讨臂踝指数检测对锁骨下动脉重度狭窄的诊断价值。方法选择经数字减影血管造影和(或)CT血管成像证实的锁骨下动脉重度狭窄老年患者48例(狭窄组),另选择无锁骨下动脉病变患者50例(对照组)。采用无创伤全自动外周动脉检测仪测量臂踝指数、两侧肱动脉收缩压差、脉搏波上行时间和脉搏波形。结果狭窄组患侧肢体的臂踝指数明显低于健侧肢体和对照组;狭窄组患侧肢体的脉搏波上行时间较健侧肢体和对照组明显延迟,差异有统计学意义。狭窄组两侧肱动脉收缩压差与对照组比较差异有统计学意义(P<0.01)。狭窄组患侧肢体的脉搏波形呈低钝波40倒(83%),呈低平波8例(17%)。结论检测臂踝指数等参数有助于快速筛查和诊断锁骨下动脉重度狭窄,为临床寻找后循环缺血的原因和更深入研究缺血性脑血管病的发病机制提供重要依据。     

锁骨下动脉闭塞或重度狭窄血管内治疗疗效及安全性分析

目的研究症状性锁骨下动脉闭塞或重度狭窄血管内治疗的疗效和安全性。方法选择31例症状性锁骨下动脉闭塞或重度狭窄的患者行血管内自膨式支架成形术,分析其疗效及安全性。结果31例症状性锁骨下动脉闭塞或重度狭窄患者中,均用自膨式支架成功完成血管内支架成形术,术后锁骨下动脉狭窄率明显改善、锁骨下动脉盗血综合征和上肢缺血症状明显改善,无并发症出现。结论采用自膨式支架治疗症状性锁骨下动脉闭塞或重度狭窄是一种微创、安全、有效的治疗方法。     

介入治疗右侧锁骨下动脉盗血综合征

目的探讨介入治疗右侧锁骨下动脉盗血综合征的特点和疗效。方法回顾分析11例右侧锁骨下动脉盗血综合征患者行血管内介入治疗的临床资料。结果 11例右侧锁骨下动脉盗血综合征患者成功置入支架,术后锁骨下动脉残余狭窄小于20%,盗血现象消失,椎-基底动脉供血不足症状消失。随访1年未发现再狭窄。结论重视右锁骨下动脉狭窄和闭塞的特殊性和复杂性,仔细了解右侧锁骨下动脉结构特点,做好手术预案是取得介入治疗成功的必要条件。     

Endothelial dysfunction in cardiologists after 24 hours on call

The objective was to determine if the stress caused by 24 hours on call in a cardiology emergency room alters endothelial function assessed by high-resolution ultrasonography in the brachial artery.Fifteen young physicians were studied in a crossover design: a) after a normal night of sleep at home, and b) after 24 hours on call without sleeping in an emergency room. Both studies were made at rest, 5 minutes after forearm occlusion and 3 minutes after administration of sublingual nitroglycerin. High-resolution ultrasonography and a 7.5-MHz linear array transducer were used to measure the brachial artery lumen.After 24 hours on call, physicians had significantly higher resting systolic and diastolic blood pressure. They also had a non-significant increase in heart rate and a lower brachial artery diameter. Brachial artery dilatation caused by hyperemia was only 3.35%, while it increased to 11.34% after normal sleep (p < 0.001). Only 2 physicians showed more than 4.4% dilatation, which was considered a normal response, while 13 had more than 4.4% after a normal night of sleep at home (p < 0.01). The response to nitroglycerin was similar under control conditions and after 24 hours of duty oncall.In conclusion, stress caused by 24 hours on call in a cardiology emergency room depresses or abolishes endothelial function.     

Angiographic prevalence and clinical predictors of left subclavian stenosis in patients undergoing diagnostic cardiac catheterization.

The angiographic prevalence, clinical predictors, and sensitivity and specificity of a bilateral arm blood pressure differential for predicting proximal left subclavian artery stenosis were established in 492 patients undergoing cardiac catheterization. Seventeen subjects (3.5%) in the overall population and nine subjects (5.3%) with potential surgical coronary disease had proximal left subclavian stenosis. Precatheterization evidence of peripheral vascular disease (PVD) was the only predictor of subclavian stenosis in the overall population (P < 0.001; OR = 7.9; 95% CI = 2.6-24.3) and in patients with potential surgical coronary disease (P = 0.04; OR = 5.4; 95% CI = 1.1-27.2). Both a bilateral blood pressure differential of > 10 mm Hg and of > or =20 mm Hg had a good specificity but a poor sensitivity for predicting left subclavian stenosis. Thus, left subclavian angiography should be performed in patients with surgical coronary disease with either an arm blood pressure differential of > 10 mm Hg or with other precatheterization evidence of PVD. Cathet Cardiovasc Intervent 2001;54:8-11.     

Subclavian balloon angioplasty in the management of the coronary-subclavian steal syndrome.

The syndrome of coronary-subclavian steal presenting with angina pectoris after coronary revascularization with the mammary arteries is not common. This disorder should be suspected in post LIMA patients with blood pressure differences between the arms and confirmed by angiography. PTA of the subclavian artery via the brachial approach, in appropriately selected patients, offers potential advantages over carotid subclavian bypass including an apparent lower complication rate with equally good results. Recurrences, which are apt to be more common after PTA versus carotid subclavian bypass, are easily managed with repeat dilatation. This course of management in our patient resulted in an excellent clinical outcome without complication. This report emphasizes the importance of considering subclavian stenosis in patients with prior LIMA bypass grafting, particularly when the ipsilateral arm blood pressure is reduced. In such cases, subclavian PTA offers a reasonable nonsurgical approach for correction.     

Clinical significance of inter-arm pressure difference and ankle-brachial pressure index in patients with suspected coronary artery disease

BACKGROUND: Although measuring blood pressure at the bilateral brachia is common in medical practice, its clinical significance in patients with suspected coronary artery disease (CAD) has not been fully clarified. METHODS: To define the significance of inter-arm systolic blood pressure difference in patients with suspected CAD, and to assess the relationship between inter-arm pressure difference and CAD, simultaneous brachial and ankle blood pressure measurements and stress myocardial single-photon emission computed tomography (SPECT) were performed in 386 consecutive patients with suspected CAD, excluding those with previous myocardial infarction or coronary revascularization. RESULTS: Subclavian artery stenosis, defined as > or = 15 mmHg inter-arm systolic blood pressure difference, was found in 27 patients (7%). Age (65 +/- 12 vs 65 +/- 11 years), male sex (21/27 vs 244/359), prevalence of hypertension(63% vs 56%), hypercholesterolemia (63% vs 62%), diabetes mellitus(33% vs 38%), cigarette smoking (44% vs 41%) and family history of CAD (15% vs 12%) were similar between patients with subclavian artery stenosis and those without. The incidence of decreased ankle-brachial pressure index (ABI) was higher (37% vs 12%, p = 0.001), and percentage ischemic myocardium as assessed by SPECT was greater (9.0 +/- 8.5% vs 5.6 +/- 6.6%, p < 0.05) in patients with subclavian artery stenosis than in those without. Furthermore, significant correlations were observed between inter-arm pressure difference and percentage ischemic myocardium (r = 0.13; p = 0.01), and ABI (r = -0.26, p < 0.0001). Among 386 patients, 283 underwent coronary angiography, and 63% of those who had inter-arm blood pressure difference had CAD. Furthermore, 83% of those CAD patients had multi-vessel CAD, which is regarded as a high-risk subset for subsequent cardiac events. CONCLUSIONS: Inter-arm pressure difference is often found in patients with suspected CAD, and is associated with significant CAD and peripheral artery disease. Thus, inter-arm pressure difference may be regarded as a simple marker for coronary and peripheral artery diseases.     

Isolated coronary ostial stenosis associated with coronary vasospasm

A 50-year-old woman was brought to the emergency room in a preshock condition. An emergency coronary angiogram revealed 90% ostial stenosis of the left coronary artery with delayed distal filling. After intracoronary nitrate, the degree of stenosis was reduced to 75%; no other coronary lesions were evident. The patient was found to have hyperthyroidism and she became euthyroid after a 2-month regimen of methimazole. A follow-up coronary angiogram showed that the left coronary artery had 50% ostial stenosis without delayed distal filling. At the same time, an aortogram showed complete occlusion of the right subclavian artery in its proximal site, a slight dilatation of the truncus brachiocephalic artery, and a diffuse wall irregularity of the abdominal aorta, suggestive of Takayasu's arteritis.     

症状性锁骨下动脉狭窄或闭塞的腔内治疗效果分析

目的 探讨症状性锁骨下动脉窃血综合征患者血管腔内技术治疗的临床有效性和安全性。方法 选取首都医科大学附属北京朝阳医院血管外科2011年1月至2015年8月收治的症状性锁骨下动脉狭窄或闭塞患者38例,其中男27例,女11例;平均年龄为（66.2±10.8）岁。患者均表现为头晕等神经系统症状,部分合并上肢缺血症状。运用血管腔内技术,对锁骨下动脉进行球囊扩张成形及支架植入术。结果 36例患者均成功植入球扩式支架,术后双上肢收缩压差显著改善,神经系统症状消失或改善33例,无效2例,1例术中发生脑梗死,经康复锻炼后好转;2例操作没成功,保守治疗。随访期间再狭窄3例,支架断裂1例。结论 严格掌握适应证,采用腔内技术治疗锁骨下动脉狭窄或闭塞的神经系统症状安全有效,操作简单。     

Iatrogenic subclavian steal syndrome

New complications are resulting from percutaneous transluminal angioplasty (PTA) and stent deployment. A 43-year-old female, admitted with weakness in the right arm, was diagnosed with right subclavian stenosis. Following PTA and a Palmaz stent deployment, her condition worsened, and symptoms spread. A corrective surgical procedure found the Palmaz stent to be almost completely compressed. The stent and plaques were carefully extracted. The etiology of compressed stent was probably due to an insufficient radial force or Hoop strength of stent. If an occlusion of the subclavian artery occurs at the segment proximal to the orifices of vertebral artery and internal mammary artery, a vertebral-subclavian steal syndrome may occur. This can be diagnosed in patients manifesting symptoms that include vertebral-basilar arterial insufficiency and a difference in brachial systolic blood pressure of at least 30 mm Hg between the two arms, with a bruit at the base of the neck or in the supraclavicular area.     

24小时动态血压监测与冠状动脉病变的关联性研究

目的研究患者24h动态血压与冠状动脉病变严重程度的关联性。方法回顾性分析我院2008年10月—2010年12月收治的127例冠心病患者临床资料,对全部患者应用冠状动脉造影术。患者冠状动脉病变严重程度以冠状动脉病变的Gensini积分与血管支数来表示。全部患者在术前与术后对肱动脉血压进行测量,术后监测24h动态血压。结果高血压组患者冠状动脉三支血管的病变患病率显著高于非高血压组,差异有统计学意义(P<0.01)。冠状动脉发生狭窄的患者,脉压与收缩压均明显高于非高血压组,差异有统计学意义(P<0.05),并且脉压与收缩压均随着患者狭窄血管其支数的增加进行增加。结论脉压是冠心病患者冠状动脉狭窄发生与发展的相关性因素,并且患者24h动态血压具有较大的预测价值,值得临床普遍推广。     

A novel approach using atherectomy for chronic total occlusion of the brachial artery: a case report

Chronic upper limb ischemia is uncommon, and is most often secondary to subclavian artery stenosis. Percutaneous intervention for subclavian stenosis usually includes balloon angioplasty and stent implantation. Brachial artery stenosis is even more scarce and accounts for approximately 12% of symptomatic upper extremity ischemia. Because it is rare, the optimal treatment strategy for brachial artery stenosis remains uncertain. We describe a case of chronic brachial artery ischemia due to atherosclerotic disease treated with the SilverHawk plaque excision system and review the available data regarding its use.     

Emergency renal artery stenting in acute anuric renal failure in children with Takayasu's arteritis

We report on emergency percutaneous renal artery stenting in two children who developed acute anuria due to bilateral renal artery stenosis and near-total occlusion. In both children, urine output could be reestablished following the procedure. One patient died from persistent severe cardiac failure. Emergency stenting is feasible, and may buy time for future procedures.     

Complete resolution of acute renal failure after left renal artery angioplasty and stent placement for total renal artery occlusion

A 25-year-old female, 17 weeks pregnant presented to our hospital with complaints of progressively increasing dyspnea. She was hypertensive with creatine of 1.0; she was transferred to ICU with multiple medications to control her blood pressure, without success. The patient continued to decompensate, which required intubation. The patient developed acute renal failure, part of her work-up suggested bilateral renal artery stenosis. She was taken to the catheterization lab and was found to have bilateral total renal artery occlusion. The left renal artery was successfully opened. The patient recovered and her blood pressure was controlled after the procedure. In the past, surgery was the preferred treatment in cases of acute renal artery occlusion. This approach has been replaced increasingly by renal artery angioplasty, which is less invasive and is at least as effective as surgical reconstruction. Our case demonstrates a percutaneous approach can be tried for totally occluded renal artery with a successful outcome.     

Flash Pulmonary Edema

Flash pulmonary edema (FPE) is a general clinical term used to describe a particularly dramatic form of acute decompensated heart failure. Well-established risk factors for heart failure such as hypertension, coronary ischemia, valvular heart disease, and diastolic dysfunction are associated with acute decompensated heart failure as well as with FPE. However, endothelial dysfunction possibly secondary to an excessive activity of renin-angiotensin-aldosterone system, impaired nitric oxide synthesis, increased endothelin levels, and/or excessive circulating catecholamines may cause excessive pulmonary capillary permeability and facilitate FPE formation. Renal artery stenosis particularly when bilateral has been identified has a common cause of FPE. Lack of diurnal variation in blood pressure and a widened pulse pressure have been identified as risk factors for FPE. This review is an attempt to delineate clinical and pathopysiological mechanisms responsible for FPE and to distinguish pathophysiologic, clinical, and therapeutic aspects of FPE from those of acute decompensated heart failure.     

Symptomatic angina secondary to coronary-subclavian steal syndrome treated successfully by percutaneous transluminal angioplasty of the subclavian artery.

Subclavian artery stenosis causing severely symptomatic angina in a patient with a previous left internal mammary artery bypass to the left anterior descending artery was treated successfully with percutaneous transluminal angioplasty. Baseline arteriography clearly revealed subclavian and coronary steal by evidence of competitive flow of nonopacified blood from the left vertebral artery. Although there was a difference of only 15 mm Hg between the right and left brachial arteries, there was a palpable difference in the upstroke of these pulses. The stenosis in the subclavian artery was successfully dilated with percutaneous transluminal angioplasty. Angiographic evidence of subclavian steal resolved following balloon dilatation, and the patient's angina was completely resolved.     

Subclavian artery stenosis: prevalence, risk factors, and association with cardiovascular diseases

OBJECTIVES: The objective was to assess the prevalence of subclavian artery stenosis (SS) in four cohorts (two free-living and two clinical populations) and determine both risk factors for this condition and the association with other cardiovascular conditions. BACKGROUND: The prevalence of SS in the general population is unknown, and its association with risk factors and other cardiovascular diseases is not well-established. METHODS: A total of 4,223 subjects (2,975 from two free-living cohorts and 1,248 from two clinical cohorts) were included in this cross-sectional analysis. Subclavian artery stenosis was defined as > or =15 mm Hg interarm pressure difference. RESULTS: The prevalence of SS was 1.9% in the free-living cohorts and 7.1% in the clinical cohorts; SS was significantly (p < 0.05) associated with past smoking (odds ratio [OR] = 1.80), current smoking (OR = 2.61), and higher levels of systolic blood pressure (OR = 1.90 per 20 mm Hg). Higher levels of high-density lipoprotein (HDL) cholesterol were inversely and significantly associated with SS (OR = 0.87 per 10 mg/dl). In regression analyses relating SS to other cardiovascular diseases, the only significant finding was with peripheral arterial disease (PAD) (OR = 5.11, p < 0.001). CONCLUSIONS: Significant SS is present in approximately 2% of the free-living population and 7% of the clinical population. Additionally, SS is correlated with current and past smoking histories, systolic blood pressure, HDL levels (inversely), and the presence of PAD. These findings suggest that bilateral brachial blood pressure measurements should routinely be performed in patients with an elevated risk profile, both to screen for SS, and to avoid missing a hypertension or PAD diagnosis because of unilateral pressure measurement in an obstructed arm.     

Renal artery stenosis

Among the indications for renal artery revascularization, either surgical or endovascular, in patients with renal artery stenosis are poorly controlled hypertension, ischemic nephropathy (preservation of renal function), or recurrent episodes of "flash" pulmonary edema and congestive heart failure. Pharmacologic treatment is the first-line therapy to control blood pressure. If the disease is unilateral, the blood pressure regimen should include an angiotensin-converting enzyme inhibitor. Guidelines published in the Sixth Report of the Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of high blood pressure should be followed. Revascularization is recommended if patients have at least 75% stenosis of one or both renal arteries, combined with resistant or poorly controlled hypertension; recurrent flash pulmonary edema; dialysis-dependent renal failure resulting from renal artery stenosis; chronic renal insufficiency and bilateral renal artery stenosis; or renal artery stenosis to a solitary functioning kidney. To treat fibromuscular disease of the renal arteries, percutaneous transluminal angioplasty is the revascularization procedure of choice. Ex vivo surgical repair of the renal artery may be required if there is significant branch renal artery stenosis. To treat atherosclerotic renal artery stenosis, the revascularization procedure of choice is percutaneous transluminal angioplasty and stent implantation, especially if there is concomitant ostial or proximal renal artery disease. Surgical revascularization is performed if concomitant aortic surgery is required, such as for abdominal aortic aneurysm.     

Stent PTA in secondary symptomatic proximal subclavian artery obstruction

Stent-PTA of secondary symptomatic proximal subclavian artery stenosis In comparison with conventional surgical revascularisation, percutaneous transluminal angioplasty (PTA) is an alternative treatment for short stenoses or occlusions involving the origin of the subclavian artery. If there is clinical suspicion of subclavian artery obstruction (e.g. blood pressure difference in both arms), digital subtraction angiography of the aortic arch and upper limb should be performed prior to creating radial haemodialysis shunts or coronary bypass crafting involving the internal mammary artery. PTA and stenting can be successfully carried out in symptomatic secondary proximal subclavian artery stenosis, e.g. in radial haemodialysis fistulas with distal ischaemia.