The ankle-brachial index in normal neonates and infants is significantly lower than in older children and adults

Vascular ageing: moving from bench towards bedside

Prevention of cardiovascular disease (CVD) remains one of the largest public health challenges of our time. Identifying individuals at increased cardiovascular risk at an asymptomatic, sub-clinical stage is of paramount importance for minimizing disease progression as well as the substantial health and economic burden associated with overt CVD. Vascular ageing (VA) involves the deterioration in vascular structure and function over time and ultimately leads to damage in the heart, brain, kidney, and other organs. Vascular ageing encompasses the cumulative effect of all cardiovascular risk factors on the arterial wall over the life course and thus may help identify those at elevated cardiovascular risk, early in disease development. Although the concept of VA is gaining interest clinically, it is seldom measured in routine clinical practice due to lack of consensus on how to characterize VA as physiological vs. pathological and various practical issues. In this state-of-the-art review and as a network of scientists, clinicians, engineers, and industry partners with expertise in VA, we address six questions related to VA in an attempt to increase knowledge among the broader medical community and move the routine measurement of VA a little closer from bench towards bedside.

Abnormal Lower Extremity Hemodynamics at Doppler US in Children with Sickle Cell Anemia

Background Children with sickle cell anemia (SCA) are predisposed to developing leg ulcers in early adolescence; however, the underlying physiologic mechanisms are not well understood, which hinders the development of prophylactic antiulcer interventions. Purpose To determine if occlusive arterial disease or abnormal hemodynamics exist in the lower limb peripheral arteries of children with SCA. Materials and Methods This was a prospective cross-sectional study conducted between July 2020 and May 2021. Two groups of participants were enrolled: children with SCA and healthy controls. Each child had their anthropometric measurements taken, followed by B-mode, color Doppler, and spectral Doppler US evaluation of the distal anterior and posterior tibial arteries. Ankle-brachial index evaluation was also performed. Hemodynamic values were compared between children with SCA and healthy controls, with statistical significance set at the P < .05 level. Results Forty-five children with SCA (mean age, 9.5 years ± 3.7 [SD]; 26 boys) and 45 healthy controls (mean age, 9.3 years ± 3.8; 25 boys) were evaluated. Children with SCA had higher peak systolic velocities, end-diastolic velocities, and blood volume flow in their distal anterior and posterior tibial arteries compared with the healthy participants (P < .001 across all 12 measurements). Children with SCA also had lower resistive index and pulsatility index values compared with healthy controls in at least one of the anterior and posterior tibial arteries bilaterally. Monophasic spectral patterns were exclusively observed in participants with SCA. The ankle-brachial index values for the participants with SCA (mean, 1.09 ± 0.08) and healthy participants (mean, 1.06 ± 0.02) were within normal range. Conclusion Abnormal peripheral hemodynamic characteristics were found in the lower limbs of children with sickle cell anemia. No evidence of occlusive peripheral artery disease was present. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Paltiel in this issue.

Pediatric peripheral vascular injuries and associated orthopedic considerations

Pediatric peripheral vascular trauma is a rare but highly morbid injury in children and is frequently associated with concomitant orthopedic injuries. These children require multidisciplinary care by pediatric, vascular, and orthopedic surgery. In this review, we describe elements of the complex care required for children with peripheral vascular trauma.

Normative and pathological values of hemodynamic and Doppler ultrasound arterial findings in children

Doppler ultrasound is an effective, useful and remarkably powerful tool in pediatric imaging. If possible, its use is always favored to avoid exposure to radiation or sedatives. By waveform spectrum analysis, Doppler ultrasound reveals information on blood flow and details on normal physiology and pathological processes undiscernible from gray-scale imaging alone. However, Doppler ultrasound remains underused, largely due to the difficult interpretation of changes in Doppler waveforms during childhood. This article provides a narrative review of the literature regarding the normative values and the physiological arterial changes through childhood according to age, weight or height, as well as frequent pathological arterial findings in children, classified by arterial territory.

Ankle Brachial Pressure Index: An update for the vascular specialist and general practitioner

Objectives

Ankle brachial pressure index (ABPI) is an invaluable tool for assessing the severity of peripheral arterial disease. In addition, it can be used as an independent marker of cardiovascular risk, with a predictive ability similar to the Framingham criteria. Identification of an abnormal ABPI should therefore trigger aggressive cardiac risk factor modulation for a patient. Unfortunately, the significance of abnormal ABPIs is poorly understood within the general medical community. This is compounded by the influence of various comorbidities on accurate measurement of ABPI, potentially leading to a wide variability in readings that need to be considered before interpretation in these patient populations. We aim to address these issues by revealing several common misunderstandings and pitfalls in ABPI measurement, describing accurate methodology, and highlighting patient cohorts in whom additional or alternative approaches may be required.

Methods

We present a narrative review of the role of ABPI in both the community and hospital setting. We have performed a literature review, exploring the validity and reproducibility of methodology for obtaining ABPI, alongside the utility of ABPI in different clinical scenarios.

Results

The measurement of ABPI is often performed incorrectly. Common pitfalls include inadequate patient preparation, failure to obtain the blood pressure from the correct lower limb artery in patients with tibial disease, failure to account for differences in brachial blood pressure between the arms, inappropriately chosen equipment and patient factors such as highly calcified arteries. Standardisation of methodology greatly improves reliability of the test. Exercise ABPI can identify significant peripheral arterial disease in patients with normal resting ABPI. In addition to its role in peripheral arterial disease, ABPI measurement has a role in assessing venous ulcers, entrapment syndromes and injured extremities; conversely, it has a more limited utility in the diabetic population.

Conclusions

A thorough understanding of the correct technique and associated limitations of ABPI measurement is essential in accurately generating and interpreting the data it provides. With this knowledge, the ABPI is an invaluable tool to help manage patients with peripheral arterial disease. Perhaps more importantly, ABPI can be used to identify and risk stratify patients with asymptomatic peripheral arterial disease, itself a major indicator of significant underlying cardiovascular disease. With the emergence of best medical therapy, targeted pharmacotherapy and lifestyle changes can reduce the risk of major cardiovascular events in high-risk patients by approximately 30%, particularly in diabetic patients. Therefore, the utility of ABPI transgresses vascular surgery, with an essential role in general practice and public health.

Arterial tree anomalies in patients with clubfoot: an investigation carried out at Soba University Hospital

Vascular deficiencies and reduced perfusion of the anterior tibial artery and the dorsalis pedis artery were suggested as causes of congenital talipes equino varus (CTEV). In this study, we assessed the prevalence of arterial abnormalities in patients with CTEV (50 patients; 74 feet) compared with a normal control group (16 patients; 32 feet) by Doppler ultrasound and Ankle Brachial Index. The flow was normal in the control group and was deficient in 39.19% of clubfoot patients. In severe clubfoot cases, the deficiency was found to an extent of 76.67%. In conclusion, the anterior tibial artery and dorsalis pedis artery are deficient in CTEV patients; to avoid postoperative skin sloughing, arterial supply must be protected using a judicious incision.

Arterial reconstructions for chronic lower extremity ischemia in preadolescent and adolescent children

OBJECTIVE

Chronic lower extremity ischemia in pediatric patients is uncommon. The intent of this study was to better define the arterial reconstructive options and their long-term durability in preadolescent and adolescent children having clinically relevant arterial occlusions affecting the lower extremity.

METHODS

The medical records of 33 consecutive pediatric patients who underwent lower extremity revascularization for chronic ischemia at the University of Michigan from 1974 to 2016 were reviewed. Patients were categorized by age, clinical manifestation, surgical intervention undertaken, and outcomes.

RESULTS

Operative treatments involved 26 preadolescent children (mean age, 6.1 years; range, 3-9 years) and 7 adolescent children (mean age, 13.9 years; range, 10-17 years). Occlusions were due to earlier injury related to catheter (14), cannula (2), or both catheter and cannula (14); penetrating trauma (2); and vasculitis (1). Preoperative manifestations included symptomatic extremity ischemia (25), growth retardation manifested by documented limb length discrepancies (21), and scoliosis (5). Primary arterial reconstructions were delayed after the precipitating vascular event an average of 5.3 and 11.2 years in the preadolescent and adolescent children, respectively. Primary procedures involved revascularizations of 36 extremities (in preadolescents and adolescents) including autologous vein (26/5), polyethylene terephthalate (Dacron; 1/0), and expanded polytetrafluoroethylene (0/3) bypasses and vein patch angioplasty (0/1). Vein grafts traversing the abdominal cavity (15) were wrapped with a synthetic mesh. Excluding one early graft occlusion, there were no major early postoperative complications after the primary procedures. Secondary operations followed 31% of the primary operations, being performed an average of 8.8 and 6.7 years later (in 8 preadolescent and 3 adolescent children, respectively) for late graft occlusions (6), graft stenoses (3), aneurysmal vein grafts (2), and anastomotic pseudoaneurysm (1). The unassisted primary graft patency rate was 69%, and the assisted secondary graft patency rate was 94%. Symptomatic ischemia resolved in all but two children. Mean postoperative ankle-brachial indices improved to 1.08 from 0.76 preoperatively. Among children having postoperative documentation of limb lengths, the limb length discrepancies became less (11), were unchanged (1), or progressed (3). Follow-up averaged 8.0 years. There was no operative mortality in this experience.

CONCLUSIONS

Primary lower extremity arterial reconstructions in children with chronic lower extremity ischemia can be successfully undertaken with excellent results. Nevertheless, the potential for late primary graft failures, evident in nearly a third of this experience, mandates careful long-term follow-up and may necessitate secondary interventions to maintain satisfactory outcomes.

Methods to evaluate arterial structure and function in children - State-of-the art knowledge

BACKGROUND

With increasing rates of hypertension, obesity, and diabetes in the pediatric population, wide available, and reproducible methods are necessary to evaluate arterial structure and function in children and adolescents.

METHODS

MEDLINE/Pubmed was searched for articles published in years 2012-2017 on methodology of, current knowledge on, and limitations of the most commonly used methods to evaluate central, proximal and coronary arteries, as well as endothelial function in pediatric patients.

RESULTS

Among 1528 records screened (including 1475 records from years 2012 to 2017) 139 papers were found suitable for the review. Following methods were discussed in this review article: ultrasound measurements of the intima-media thickness, coronary calcium scoring using computed tomography, arterial stiffness measurements (pulse wave velocity and pulse wave analysis, carotid artery distensibility, pulse pressure, and ambulatory arterial stiffness index), ankle-brachial index, and methods to evaluate vascular endothelial function (flow-mediated vasodilation, peripheral arterial tonometry, Doppler laser flowmetry, and cellular and soluble markers of endothelial dysfunction).

CONCLUSIONS

Ultrasonographic measurement of carotid intima-media thickness and measurement of pulse wave velocity (by oscillometry or applanation tonometry) are highly reproducible methods applicable for both research and clinical practice with proved applicability for children aged ≥6 years or with height ≥120cm. Evaluation of ambulatory arterial stiffness index by ambulatory blood pressure monitoring is another promising option in pediatric high-risk patients. Clearly, further studies are necessary to evaluate usefulness of these and other methods for the detection of subclinical arterial damage in children.

Ankle-Brachial Index, Toe-Brachial Index, and Pulse Volume Recording in Healthy Young Adults

OBJECTIVE

To clarify the characteristics of ankle-brachial index (ABI), toe-brachial index (TBI), and pulse volume recording (PVR) of the ankle with brachial-ankle pulse wave velocity (baPWV) in healthy young adults.

MATERIAL AND METHODS

We analyzed ABI, TBI, baPWV, and PVR in the ankle of healthy adults aged 20 to 25 years (median, 20 years) using an automatic oscillometric device between 2002 and 2013. The ABI, baPWV, and PVR in 1282 legs of 641 subjects (301 men and 340 women) and the TBI in 474 toes of 237 subjects (117 men and 120 women) were evaluated.

RESULTS

The measured values showed no bilateral differences. ABI and baPWV were higher in men than in women, but TBI was similar in both sexes. ABI <1.0 was observed in 18.1% of the legs in men and in 25.6% in women. TBI <0.7 was observed in 16.2% of the toes in men and 19.1% in women. For ankle PVR, the % mean arterial pressure was higher in women than in men. The upstroke time was <180 ms in most subjects.

CONCLUSIONS

For young people, ABI <1.0 or TBI <0.7 may not always indicate vascular abnormalities. When evaluating circulatory indexes, age and sex should be considered.

Acute Limb Ischemia in Pediatric Population Secondary to Peripheral Vascular Cannulation

Introduction:

In this article, we discuss published literature on the management of pediatric patients with acute limb ischemia and also present our center’s experience.

Results:

Literature review suggests that in the absence of imminent risk of limb loss, noninterventional management with anticoagulants and systemic thrombolysis is preferable and associated with better clinical outcomes than surgery such as reduced per operative morbidity and mortality. In selected more severe cases, surgery may be required. We propose an algorithm for improved clinical outcomes based on the published literature and the American College of Chest Physicians’ recommendations for antithrombotic management in the pediatric population.

Conclusion:

Literature review suggests an inverse relationship between age and surgical success, particularly in preschool pediatric population. Conservative management as a preliminary strategy seems most beneficial. It is hoped that the proposed intercalated algorithm of medical and surgical management of these patients can further improve clinical outcomes.

A high normal ankle-brachial index is associated with proteinuria in a screened cohort of Japanese: the Okinawa Peripheral Arterial Disease Study

OBJECTIVES

We hypothesized that ankle-brachial index (ABI) increased with age as a result of arterial stiffness, and decreased when flow-limiting atherosclerotic stenosis occurred in the lower limbs. As arterial stiffness is associated with proteinuria, we investigated the relationship between ABI and prevalence of proteinuria.

METHODS

A cross-sectional study of ABI and proteinuria with 13,193 participants aged 21-89 years (53% women) from health checkups between July 2003 and March 2010 was conducted. ABI was measured using the automatic oscillometric method, and stratified into four groups: ABI ≤ 0.9 (low); 0.9 < ABI <1.0 (borderline low); 1.0 ≤ ABI <1.2 (normal); and 1.2 ≤ ABI <1.4 (high normal).

RESULTS

In participants with ABI at least 1.0, ABI was positively correlated with SBP, pulse pressure, and brachial-ankle pulse wave velocity. In participants with ABI less than 1.0, all indices were negatively correlated with ABI. The prevalence of proteinuria, defined as ≥ 1+ by dipstick, was significantly higher in low (23%) and high normal ABI (10%) compared with borderline low (6%) and normal ABI (7%). In participants at least 60 years, proteinuria was significantly associated with only low ABI [odds ratio (OR) 3.22, 95% confidence interval 1.34-7.41] compared with normal ABI before and after multivariable adjustment. In participants less than 60 years, adjusted OR for proteinuria was only significantly associated with high normal ABI (OR 1.32, 95% confidence interval 1.01-1.74).

CONCLUSION

High normal ABI in younger participants may be a result of arterial stiffness and associated with proteinuria.

Paediatric extremity vascular injuries - experience from a large urban trauma centre in India

INTRODUCTION

Paediatric extremity vascular injuries are infrequent, and management protocols draw significantly from adult vascular trauma experience necessitating a continuous review of evidence.

MATERIALS AND METHODS

A retrospective registry review of all consecutive patients younger than 18 years age treated for extremity vascular trauma from 2007 to 2012 was carried out. Diagnostic algorithm relied little on measurement of pressure indices. Data was collected about demographics, time since injury, pattern of injury, ISS, initial GCS and presence of shock, results of diagnostic modality and treatment given with associated complications. Patients completing 2 years follow up were assessed for functional disability and vascular patency. A multivariable regression model was used to evaluate effects of - ISS, presence of orthopaedic injury, soft tissue injury, neural injury and arterial patency at the end of 2 years - on outcome of functional disability.

RESULTS

Paediatric extremity vascular injuries accounted for 0.68% hospital admissions with a median delay of 8h from injury. 82 patients were included with 50 cases examined for long term outcome. Patient cohort was overwhelmingly male, with 'fall', 'road traffic injury' and 'glass cut' being most common injury mechanisms. CT angiography and duplex scan based diagnostic algorithm performed satisfactorily further identifying missed injuries and aiding complex orthopaedic reconstruction. Brachial and femoral vessels were most commonly injured. Lower extremity vascular injury was found associated with significantly higher ISS and requirement for fasciotomy. Upper extremity vascular injury was associated with higher odds of neural injury. Younger children were at higher risk of combined radial and ulnar vessel injury. No patient satisfactorily complied with post-operative anticoagulant/antithrombotic prophylaxis. 28 patients had good functional outcome with unsatisfactory functional outcome found associated with significantly higher ISS, presence of orthopaedic and neural injury, along with absence of arterial patency.

CONCLUSION

The epidemiology of paediatric peripheral vascular injury differs in India compared to west. Certain traditional management principles of extremity vascular trauma may stand uniquely challenged in the paediatric population.

Cross-talk between macro- and microcirculation

Physiologically, macro- and microcirculation differ markedly as macrocirculation deals with pulsatile pressure and flow and microcirculation with steady pressure and flow. Various such haemodynamic aspects correspond to a large heterogeneity in the structure and function of the vascular tree. In the past, diseases such as hypertension and diabetes mellitus were classified on the basis of the structure and function of small and large arteries. The purpose of this paper is to review the cross-talk between the micro- and macrocirculation. We shall discuss this cross-talk from the perspective of the development, physiology and pathology of the entire arterial tree.

Measurement, calculation, and normal range of the ankle-arm index: a bibliometric analysis and recommendation for standardization

Since its introduction in 1950, a variety of methods of measurement and calculation have been used to establish the ankle-arm index (AAI). This has resulted in variations of its normal range and difficulty in comparing study results. Hence, the objective of our study was to analyze the disparate methods used to assess AAI and its normal range and to recommend a standardized method to assess AAI based on that analysis. We made an inventory of the disparate AAI methods and its normal range reported in 100 randomly selected publications and recommend the means of such standardization. We recommend that an experienced observer assess AAI with the patient at rest in the supine position. The width of the sphygmometer cuffs should be 1.5 times that of the extremity to be measured, and brachial and crural pulses should be detected using a Doppler device. Systolic pressures should be measured at both arms and over the anterior and posterior arteries of both legs, with the cuff placed just proximally to the malleoli. The left arm pressure ought to be used as denominator and the mean of pressures of both crural arteries of each leg ought to be used for the numerator of the AAI for that leg. We advocate 0.90 as the cut-off value to distinguish patients who need further arterial assessment.

The Validity, Reliability, Reproducibility and Extended Utility of Ankle to Brachial Pressure Index in Current Vascular Surgical Practice

BACKGROUND

Despite the increasing sophistication of vascular surgical practice, more than three decades after its introduction to clinical practice, the ankle to brachial pressure index (ABPI) remains the cornerstone of non-invasive assessment of the patient with symptomatic peripheral arterial disease (PAD).

AIM

To summarise what is known about ABPI and critically appraise its validity, reliability, reproducibility and extended utility.

METHODS

A MEDLINE (1966-2004) and Cochrane library search for articles relating to measurement of ABPI was undertaken; see text for further details.

RESULTS

There is considerable disagreement as to how ABPI should be measured. Furthermore, various factors, including the type of equipment used, and the experience of the operator, can result in significant inter- and intra-observer error. As such, care must be taken when interpreting data in the literature. ABPI is valuable in the assessment of patients with atypical symptoms, venous leg ulcers and after vascular and endovascular interventions. However, absolute pressures are probably more valuable in patients with critical limb ischaemia. ABPI is also useful in subjects with asymptomatic PAD where it correlates well with, and may be used in screening studies to quantify, cardiovascular risk.

CONCLUSIONS

While its apparent simplicity can beguile the unwary, ABPI will continue to have a key role in the assessment of symptomatic PAD. ABPI is also likely to have extended utility in health screening and institution of best medical therapy in asymptomatic subjects.