Practical guide of vascular ultrasound in arteriovenous fistulae.

The use of vascular ultrasound, especially with the increasing prevalence of percutaneous arteriovenous fistulas, has taken a central role as a diagnostic and therapeutic imaging procedure in vascular access creation. The current review article stresses the importance of vascular ultrasound in arteriovenous fistula, from planning to creation to maintenance. It summarises and gives practical guidance regarding sonographic criteria for vascular access procedure planning, the application of vascular ultrasound intraoperatively and during follow-up. Ultrasound education and training modalities to meet high standards of patient care in hemodialysis are presented.

Ultrasound-guided venous pressure measurement.

Current standard technique for venous pressure measurement is still invasive, requiring insertion of a catheter. Additionally, clinical estimation of central venous pressure (CVP) has proven unreliable compared to invasive methods. Meanwhile, different non-invasive ultrasound guided modalities may provide a valid alternative to invasive venous pressure measurement. Particularly promising is a novel compression ultrasound (CUS) which combines ultrasound properties with a tissue pressure manometer enabling even further future applications. This review provides an overview using ultrasound guided non-invasive venous pressure measurement (UGPni) in clinical trials so far and focuses on three objectives: (1) To summarize the main methods using UGPni for central venous pressure measurement (2) To outline the key findings of previous clinical trials for UGPni regarding CVP measurement with primary focus on novel compression ultrasound of a forearm vein (3) To point out limitations and possible future clinical implications of these ultrasound modalities UGPni represents an easy-to-perform and safe alternative to invasive "gold standard" diagnostic tools for measuring central venous pressure. After a brief introduction, non-specialist personnel using a portable ultrasound device can apply this method in a feasible way. Of all mentioned methods in this review CUS is the method of choice underscoring its ability to assess a patient's CVP categories correctly. Furthermore, detection of non-invasive central venous pressure in the emergency room represents an independent predictor for cardiac rehospitalization in patients with decompensated heart failure, thus helping in risk stratification as well as being an additive tool in general hemodynamic management of critically ill patients. This review concludes a significant role for ultrasound guided non-invasive venous pressure measurement suitable for a wide range of everyday clinical practice. However, further studies are warranted to proof a causal relationship in this regard.

Association of Intrarenal Resistance Index and Systemic Atherosclerosis After Kidney Transplantation.

BACKGROUND/AIM: Patients after kidney transplants are at risk of cardiovascular morbidity. An elevated resistance index (RI) is associated with renal graft failure, while a decreased RI can be due to a renal artery stenosis. The RI can also be measured in the carotid artery. Whether a correlation between intrarenal RI after kidney transplant in adult patients and the RI of the internal carotid artery exists is still unclear. PATIENTS AND METHODS: In this prospective cross-sectional study, RI of kidney transplants and of the internal carotid artery were measured with duplex sonography. Carotid intima-media thickness as well as the Framingham risk score and the Augmentation index, all known markers of atherosclerosis, were assessed. Correlations between the RI in Carotid artery and the RI of the kidney transplant were based on Spearmen test with the level of significance set at p<0.05. RESULTS: Ninety-eight consecutive patients [60% male, mean age of 48.7 (±15.6)] were included. The mean interval after transplantation was 27.5 (±8.5) months and mean serum creatinine was 308 (±220.3) mmol/ml The RI of the internal carotid artery and the renal transplant were significantly correlated (p<0.05). A correlation between the RIs and the Augmentation Index was found. CONCLUSION: The RI of the kidney transplant is correlated with the RI of the carotid artery and to markers of general atherosclerosis. This observation may be helpful to identify patients after kidney transplant with higher risk for cardiovascular events and gain indirect information on transplant renal artery stenosis.

External stenting and disease progression in vein grafts 1 year after open surgical repair of popliteal artery aneurysm.

OBJECTIVE: Open surgical repair remains the gold standard treatment for popliteal artery aneurysms (PAA). The objective of this study was to evaluate the safety of external stenting and its medium-term effect on vein graft disease after open PAA repair. METHODS: Between December 2017 and September 2019, 12 consecutive patients with PAA underwent open surgical repair with externally stented saphenous vein grafts. Duplex ultrasound scanning of the grafts was performed at discharge and at 3, 6, and 12 months after the procedure to evaluate graft patency, average lumen diameter and lumen uniformity. RESULTS: Eleven patients underwent aneurysm ligation and bypass grafting and one patient was treated with aneurysm exclusion and interposition of a venous segment. External stenting of the vein graft was successful in all patients. The mean follow-up time was 12 months (range, 7-17 months), with a primary patency rate of 100% and no graft revisions or reinterventions. The mean lumen diameters at 3, 6, and 12 months were 5.9 ± 1.2 mm, 5.7 ± 0.8 mm, and 5.7 ± 0.7 mm, respectively, with no significant changes between 3 and 6 (P = .34) and between 6 and 12 months (P = .34). The coefficient of variance at 3, 6, and 12 months was 8.2 ± 9.3, 9.4 ± 7.2, and 10.4 ± 8.9, respectively, with no significant change between 3 and 6 months (P = .78) or 6 and 12 months (P = .98). No mortality or amputations were recorded throughout the follow-up period. CONCLUSIONS: External stenting of vein grafts in open surgical repair of PAA is feasible and safe. This technique may potentially improve the outcomes of surgical repair in patients with PAA.

Exercise induced leg pain due to endofibrosis of external iliac artery.

Due to monotonous movement patterns, muscular hypertrophy, and increased cardiac output peripheral vasculature of athletes are subject to extreme stresses during athletic performance. Individuals suffering from exercise induced non-traumatic lower leg pain may display underlying vascular pathology such as external iliac artery endofibrosis. Therefore, it is essential in the course of to discriminate vascular from non-vascular findings and prime the correct diagnostic path within the course of clinical examination. In this regard, interdisciplinary thinking and profound knowledge in exercise-associated pathologies of the musculoskeletal, nervous and vascular system is indispensable. Consequently, provocation testing displays an indispensable diagnostic tool and has to be continued until symptoms occur, or complete exhaustion is attained. Finally, selective assessment of conservative and surgical treatment options, as well as its ethical evaluation, are of major importance in order to protect, preserve and promote the health and physical integrity of our patients who are keen to perform.

PAD screening: why? whom? when? how? - a systematic review.

An estimated 237 million people suffer from peripheral arterial disease (PAD), which is associated with high morbidity and mortality, and prevalence is still increasing. Currently, we do not have any randomized trials that compare screening to no screening specifically for PAD in the general population. Presently, PAD screening is not generally established. This systematic review gives an overview of relevant literature and guidelines. Screening usually focuses on ankle-brachial index (ABI)-measurement, which enables detection of asymptomatic and symptomatic PAD, but has limitations in diabetics. There are no sufficient data on PAD screening. Guideline recommendations are heterogeneous. While some advocate no screening until better data are available, most recommend selective screening despite insufficient data on morbidity and mortality reduction in consequence of screening. We support the only evidence-based screening strategy for PAD: combined screening for abdominal aortic aneurysm (AAA), PAD and arterial hypertension in men aged 65-74 according to the VIVA study. We additionally suggest a new simple three-step screening strategy for symptomatic PAD in all individuals aged 40 and older, who see a general practitioner: Asking one question ("Do you have pain or cramps in the legs during normal walking?") followed by physical examination (normal lower extremity pulse status?) in those, whose answer is "yes", and ABI measurement unless all pulses are normal.

[Not Another Arm Vein Thrombosis - Memories of the Past]. / Nicht schon wieder eine Armvenenthrombose ­ Erinnerungen an die Vergangenheit.

Not Another Arm Vein Thrombosis - Memories of the Past Abstract. This article points out relevant differential diagnoses of a unilateral arm swelling that is a key clinical sign of an upper extremity vein thrombosis. The presented case is a patient with a symptomatic, iatrogenic arteriovenous fistula between the subclavian artery and vein due to central venous port system implantation.

Symptomatic type I endoleak following popliteal artery aneurysm repair.

A case of a symptomatic type Ib endoleak following popliteal artery aneurysm repair with successful interventional therapy introduces a short review of the limited literature to this relevant potential complication. Illustration of important factors supporting endoleak formation after endovascular popliteal artery repair and recommendation of a consequent surveillance are discussed.

Prevalence of carotid plaque stenosis after head and neck radiotherapy - an observational study of 156 survivors.

Background: Radiotherapy for head and neck cancer (HNC) represents a well-known predisposing factor for asymptomatic carotid artery lesions and acute cerebrovascular accidents. Our aim is to provide contemporary estimates on the prevalence, severity, and characteristics of carotid artery lesions in HNC survivors. Patients and methods: We prospectively included HNC patients who underwent radiotherapy and were free from the disease at the time of duplex ultrasound evaluation. Patients were re-contacted telephonically and those who agreed to participate were invited for an ambulatory visit when the investigators collected clinical information and performed duplex ultrasound examination based on a predefined protocol. Results: A total of 156 patients were included and underwent duplex ultrasound examination after a mean of 65.2 months from the last session of radiotherapy. A total of 36 patients (23.1%) had normal carotid arteries; mild, non-stenotic lesions were observed in 49.4% (n = 77) of patients; severe stenotic plaques were found in 27.5% (n = 43) of patients. One patient found with an asymptomatic occlusion of the left ICA. The prevalence of major cardiovascular risk factors and high radiation dose increased proportionally with plaque severity. Low echogenicity plaque was found in 59 (37.8%) patients on the right side and 57 (36.5%) on the left side; long segment plaque in 49 (31.4%) patients on the right side and in 47 (30.1%) on the left side; an atypical location of the lesions in 42 (26.9%) patients on the right side and in 48 (30.8%) on the left side. Conclusions: The prevalence of occlusion and severe stenosis after radiotherapy for HNC was very low in our study population. Low echogenicity plaque, long segment plaque, and an atypical location were common findings. Classic cardiovascular risk factors appear to have had a causative role: a routine screening of radiotherapy-treated patients might be necessary only in patients with concomitant cardiovascular risk factors or exposed to high-dose neck radiation.

Farbkodierte Duplexsonografie der Gefässe in der Praxis: Pitfalls.

Color Doppler ultrasound is the diagnostic cornerstone of vascular assessment. Almost all arteries and veins of the human body are accessible to this diagnostic imaging, which as a result is very often used as first-line diagnostic test. Recent technological developments in high-end ultrasound machines enable us to optimize image quality in color-coded duplex ultrasound of arteries and veins. To obtain an optimal instrument setting, all relevant adjustments of imaging must be considered. In B-Mode ultrasound, the basic vascular imaging method, the most important settings to optimize are ultrasound frequency, gain, dynamic range, and focus, whereas color Doppler depends on angle supersonic sounding and its application in clinical practice. Most mistakes in measuring blood flow velocities, a frequent cause of misinterpretation, result from insufficient angle correction. Cardiac pathologies may result in typical changes of arterial and venous Doppler curves.

[Vascular Color-Coded Duplex Ultrasound in Practice: Artifacts]. / Farbkodierte Duplexsonografie der Gefässe in der Praxis: Artefakte.

Vascular Color-Coded Duplex Ultrasound in Practice: Artifacts Abstract. Ultrasound artifacts are technical phenomena which may cause diagnostic mistakes and do not correlate with the real target organ. These optical and acoustic phenomena of color-coded duplex ultrasound are very common in the real world and may lead to misinterpretations and diagnostic errors. The twinkling artifact, for example, imitates high-flow velocities and turbulences, which may lead to the misdiagnosis of a high-grade stenosis or of vascularization. Mirror image artifacts may irritate the sonographer and cause an impression of an additional - really not existing - vessel. The "seagull cry", whose origin is not well understood, is usually found in the region of a high-grade stenosis.

[Non-Invasive Diagnostics of Arteriosclerotic Manifestations]. / Nicht invasive Diagnostik bei Manifestationen der Arteriosklerose.

Arteriosclerosis is a generalized disease and manifests in different vascular regions: the most important manifestations are the coronary artery disease, the peripheral artery disease and the cerebrovascular arteriosclerosis. The challenges of modern ultrasound systems to detect early vascular damage are reviewed in this article. Colour coded duplex ultrasound is the first line method for screening and diagnostic imaging in vascular disease. Indications for further imaging as CT-angiography, MR-angiography and digital subtraction angiography will be discussed in the different sections.

Non-invasive ultrasound-based imaging of atherosclerosis.

Early detection of vascular damage in atherosclerosis and accurate assessment of cardiovascular risk factors are the basis for appropriate treatment strategies in cardiovascular medicine. The current review focuses on non-invasive ultrasound-based methods for imaging of atherosclerosis. Endothelial dysfunction is an accepted early manifestation of atherosclerosis. The most widely used technique to study endothelial function is non-invasive, flow-mediated dilation of the brachial artery under high-resolution ultrasound imaging. Although an increased intima-media thickness value is associated with future cardiovascular events in several large population studies, systematic use is not recommended in clinical practice for risk assessment of individual persons. Carotid plaque analysis with grey-scale median, 3-D ultrasound or contrast-enhanced ultrasound are promising techniques for further scientific work in prevention and therapy of generalized atherosclerosis.

[Contrast-Enhanced Ultrasound (CEUS) for Surveillance after Endovascular Aortic Aneurysm Repair (EVAR)]. / Kontrastmittelverstärkter Ultraschall (CEUS) in der Verlaufskontrolle nach endovaskulärer Aneurysmaausschaltung (EVAR).

Contrast-Enhanced Ultrasound (CEUS) for Surveillance after Endovascular Aortic Aneurysm Repair (EVAR) Abstract. Minimally invasive endovascular aneurysm repair is the most common technique for symptomatic and larger aortic aneurysms. Possible complications, e.g. endoleaks, may occur any time, therefore the patients need a life-long surveillance program after aneurysm repair. This article gives an overview of the surveillance of endografts with a special focus on contrast-enhanced ultrasound.