Hear, hear for ultrasound

Ultrasound technology is finally being used outside of the hospital setting. The simple, non-invasive and radiation-free imaging modality is now a reality in the medical aesthetic clinic. Ultrasound has been recognised as a suitable investigation in aesthetic complications since 2008 and recommended in practice since 2013. Technological advances have enabled professionals to deliver imaging in any environment. In treatment planning, delivery and aftercare, patient outcomes can be optimised. Ultrasound imaging allows reliable dermal filler identification, vascular mapping, management of vascular compromise and nodules, real-time rheology and measurement in relation to treatment outcomes. The challenges that remain relate to underpinning availability and enthusiasm with education and support. At the time of writing, there are no such mechanisms or educational programmes.

Hemodialysis AV Fistula: What a Radiologist Should Know?

Hemodialysis works as a lifeline for end stage renal disease patients. Creation and maintenance of vascular access for dialysis is the mammoth task. Due to increased references related to vascular access; number of complications are faced in pre as well as post operative period of vascular access creation. Ultrasound and color Doppler study play a major role in imaging throughout this period. Pre operative vascular mapping is very crucial to help surgeon to determine the proper site and surgical technique for vascular access creation. Early and delayed post operative complications can also be diagnosed with ultrasound and color Doppler study. Here we have tried to cover all the important points which a radiologist should consider during pre operative vascular mapping and post operative evaluation of vascular access as well as any associated complications.

VAVASC study: Clinical trial protocol

Background: VAVASC study (Validation of Arterio Venous Access Stage Classification) is a multicentre, international, prospective study. The study aims to validate the AVAS classification, which is a classification system describing vascular status of patients indicated for creation of arteriovenous access on the upper limb. Methods: Observational, prospective, multicentre, international study starting in March 2021. Participant recruitment has commenced. Basic demographic data, risk factors and vascular mapping parameters are collected via an online platform. The outcome measures are class of AVAS, predicted arteriovenous access, final arteriovenous access that has been created and a functionality of the arteriovenous access. Predictive models will be used for statistical analysis. Current status: A total of 140 patients from 4 centres in Great Britain, Czech Republic, Brazil and Slovakia are already included and undergoing evaluation. Conclusions: The study is registered in the Clinical trials registry (NCT04796558), https://register.clinicaltrials.gov/ . Study is still open for collaboration with other centres that can register via www.vavasc.com .

MO774PREDICTIVE FACTORS FOR PROSTHESIC ARTERIOVENOUS FISTULA OPTION BY DUPLEX DOPPLER ULTRASOUND VASCULAR MAPPING

Background and Aims Vascular access (VA) remains the lifeline for hemodialysis (HD) patients. Arteriovenous fistulas (AVF) are recommended over prosthesic arteriovenous fistula (PAF). However, the choice of the type of VA still reflects local practice differences and patient-specific demographic and clinical factors. Duplex Doppler ultrasound (DDU) has been shown to be useful in evaluation of both structural and functional aspects of the peripheral vessels, and is emerging as the preferred method for VA planning. Our aim was to find predictive factors for PAF creation in our population, i.e. when AVF was not feasible. Method We retrospectively analysed a cohort of chronic kidney disease patients who underwent DDU vascular mapping for preoperative planning of HD access at a tertiary referral centre from 2019 to 2020. All the exams were performed by the same DDU operator. Demographic, clinical and DDU characteristics were studied. Continuous variables were recorded as means (±SD) for normally distributed data or as medians (interquartile ranges) for non-normally distributed data. Comparisons were made using t tests or Wilcoxon rank sum tests as appropriate. Categorical variables were evaluated by frequency distribution and recorded as proportions. Comparisons were made using the x2 test. Unadjusted and adjusted multivariate logistic regression models were fitted to identify risk factors to PAF creation due to not being a good candidate for AVF. Results A total of 252 patients were included. The mean age was 65±16 years, 144 (57%) were male, 211 (84%) where white, 40 (16%) were black and 1 (0.4%) was asian. Two hundred and thirty seven (94%) patients were right-handed and 186 (74%) were being evaluated for the first vascular access. The majority had arterial hypertension (HT) (205 (81%)); 98 (39%) had Diabetes Mellitus (DM), 89 (35%) were current or past smoker and 72 (29%) were obese. Most patients were considered appropriate candidates for AVF (207, 82%), whereas 45 (18%) were assigned to PAF. Figure 1 compares the DDU’s arterial indexes of each group. In a multivariate logistic regression model adjusted for age, sex, HT, DM and obesity, black race was found to be a predictor of being a candidate for PAV creation (OR 2.46; CI 95% 1.05-5.71; p-value 0.036). Conclusion Our study revealed that black race is an independent factor for PAV creation even after adjusting for classic risk factors as age, DM or HT. Long known insidious factors, such as poor socioeconomic status or poor access to medical care, have been pointed as justifiers to this disparity. However, facing the PAF-associated risks, we believe that further work must be done to clarify potential involved anatomical factors and potential reversible factors. Those patients have been described throughout the literature as presenting with higher risk of VA failure and severe peripheral arterial disease. In parallel we found that radial and ulnar arteries diameters and radial pulse wave velocity (PWV) in DDU were significantly lower in PAV-submitted patients, suggesting distal arterial compromise and stiffness. Our work has some limitations: neither vein parameters nor VA outcomes were analysed. However, it introduces a relationship between the black race and worse arterial indexes, and their impact on the choice of type of VA, as they seem not to be good candidates for AVF.

MO773THE VASCULAR REALITY BEHIND ULTRASOUND VASCULAR MAPPING: WHICH FACTORS PREDICT THE BEST CANDIDATES FOR RADIOCEPHALIC ARTERIOVENOUS FISTULA?

Background and Aims Vascular accesses (VA) are key components for efficient hemodialysis. Arteriovenous fistulas (AVF) are recommended over arteriovenous graft (AVG), but deciding the type and location of a VA is challenging. Preoperative vascular mapping before surgical creation of VA, especially trough ultrasound (US), is helpful in this decision, contributing to improve AVF e AVG outcomes. Our study aims to identify patient factors associated with appropriate arterial US parameters that predict feasibility for radiocephalic fistula creation. Method We analyzed a cohort of chronic kidney disease patients who underwent US vascular mapping for preoperative planning of dialysis access from 2019 to 2020, in a tertiary referral center. Patients were characterized based on its demographical characteristics, and the presence of diabetes, hypertension, obesity, and smoking. Arterial indicators were analyzed by ultrasound techniques in both upper arms, including radial, ulnar and brachial arteries. Those indicators included arterial diameter, calcification, doppler wave form, and pulse wave velocity. Continuous variables were recorded as means (±SD) for normally distributed data and as medians (interquartile ranges) for nonnormally distributed data. Comparisons were made using t tests or Wilcoxon rank sum tests as appropriate. Categorical variables were examined by frequency distribution and recorded as proportions. Comparisons were made using the x2 test. Unadjusted and adjusted multivariate logistic regression models were fitted to identify predictors for a good candidate for radiocephalic arteriovenous fistula. Results A total of 252 patients were included. The mean age was 65±16 years, 144 (57%) were male, 211 (84%) where white, 40 (16%) were black, and 1 (0.4%) was asian. Most had arterial hypertension (205, 81%), 98 (39%) had diabetes mellitus, 89 (35%) were smokers, and 72 (29%) were obese. The majority of patients were attending for the first VA (186; 74%). Most patients were considered appropriate candidates for arteriovenous fistula creation (207, 82%), whereas 45 (18%) were assigned to PTFE graft. Obesity and male sex were found to be predictors for being a good candidate for radiocephalic arteriovenous fistula in a multivariate logistic regression model adjusted for age, hypertension, and diabetes (OR 3.21, CI 95% 1.63-6.32, p-value 0.001 and OR 2.09, CI 95% 1.07-4.08, p-value 0.031, respectively). Figure 1 presents the arterial indicators analyzed during ultrasound mapping, including both upper limbs. Conclusion Our results show that obesity and male sex are predictors for radiocephalic arteriovenous fistula creation. While female sex has long been known to be a risk factor for VA failure, possibly because of worse arterial indicators, an association between obesity and higher probability of distal AVF creation has not been established yet. Comparison between arterial indicators in obese and nonobese patients shows that obese patients generally have better arterial indicators, especially higher pulse wave velocities, and less arterial calcification. Given that some studies show an association between obesity and shorter fistula survival (due to higher secondary failure rate), our results may come as. A possible explanation for this difference is that obesity may exert a physical protective effect of the forearm vascular bed against iatrogenic damage (blood sampling and vessel cannulation). Besides that, factors other than vascular indicators may contribute to ulterior VA failure, like the proinflammatory state in obese patients and its consequent myointimal hyperplasia. However, our conclusions are based on preoperative findings, and not on VA outcomes, especially its patency and complications. Moreover, which further help to determine the better location for a VA creation, were not evaluated in this study.

Diagnostic possibilities of the method of elastography and shear wave steatorei patients with non-alcoholic fatty liver disease

The steady increase in the number of patients with chronic diff use liver diseases, including non-alcoholic fatty liver disease, leads to the need to introduce non-invasive methods of diagnosis and monitoring changes in the structure of the organ into clinical practice.Objective. To evaluate the possibility of using shear wave steatometry and elastography in the diagnosis of fi brosis stage and degree of steatosis in patients with non-alcoholic fatty liver disease.Materials and methods of research. The study involved 52 patients of the I. I. Mechnikov NWSMU clinic with NAFLD, 28 of them men and 24 women, the average age was 51-+11.2 g, the average BMI-30,7-+5,4 kg / m2. The control group consisted of 20 healthy volunteers. All patients underwent complex ultrasound on the Angiodin-Sono/P-Ultra device (Bioss, Russia) with a 1–6 MHz convexic sensor (B-mode, Doppler modes—vascular mapping and spectral pulse, shear wave elastometry, elastography (active and natural compression—Active / Natural Strain)).