Predictors of Radial Artery Size in Patients Undergoing Cardiac Catheterization: Insights From the Good Radial Artery Size Prediction (GRASP) Study

Snuffbox distal transradial access (dTRA) for arteriovenous fistuloplasty in Singapore: Going distal is safe

AIM

Arteriovenous fistula (AVF) dysfunction resulting from stenosis or occlusion, is a prevalent issue in end-stage renal failure patients reliant on autogenous AVFs for dialysis. Recently, a distal transradial approach (dTRA) has emerged, offering advantages such as diminished access site complications, better patient comfort and reduced risk of radial artery occlusion. Our study seeks to assess the effectiveness, outcomes and complication rates of employing dTRA for arteriovenous fistuloplasty in Singaporean patients.

METHODS

A retrospective review of all dTRA fistuloplasties performed on dysfunctional or slow to mature AVFs from 2017 to 2023 in our institution was performed. Patients with a distal radial artery measuring 2 mm or more with no evidence of occlusion or thrombosis were included. Patients who required central venoplasty or cutting balloon angioplasty were excluded. Outcome measures included technical success, mean procedure duration, complications and post-intervention primary patency at 1, 3 and 6 months. Patients were followed up for 12 months post-intervention.

RESULTS

A total of 37 patients were included. 97.3% of patients undergoing dTRA fistuloplasty had radiocephalic fistulas while 2.7% had brachiobasilic fistulas. There was 100% technical success (defined as success in radial artery cannulation, sheath insertion and crossing of stenotic lesions) in our study as all patients successfully underwent fistuloplasty via dTRA approach. One-month patency rate was 97.4%, 3-month patency rate was 92.1% and 6-month patency rate was 86.8%. There were no immediate complications (haematoma, infection, bleeding, pseudoaneurysm, occlusion) of the radial artery post-intervention.

CONCLUSION

Our paper illustrates the safety and efficacy of utilising dTRA for arteriovenous fistuloplasty. This approach offers distinct benefits in addressing non-mature or dysfunctional distal forearm arteriovenous fistulas and should be taken into account in anatomically suitable cases.

Evaluation of the Relationship Between Radial Artery Intima Media Thickness and Complications at the Intervention Site After Radial Angiography

The present study investigated the relationship between pre-procedural radial intima-media thickness (rIMT) and radial artery thrombosis (RAO) in patients undergoing angiography using a transradial approach (TRA). Patients (n = 90) who underwent cerebral or peripheral arterial angiography using TRA were included in the study. Ultrasonographic evaluation was performed before and 12 h after the procedure. Preoperative rIMT measurement was performed at the distal radial artery. Presence of radial artery occlusion was evaluated by ultrasonography after radial catheterization and revealed occlusive thrombus in the radial artery in 13 patients. rIMT was found to be statistically significantly higher in patients with thrombus (P < .05). When it was evaluated whether there was a correlation between age and rIMT, a positive significant correlation was found (P < .01). Our study suggests that increase of rIMT may be a risk factor for RAO in the intervention area. Before the procedure, ultrasound (US) assessment of the radial artery may be useful in determining the risk of occlusion. Thus, RAO-related technical risk factors (procedure time, number of punctures, sheath thickness, etc.) can be managed more carefully in patients having radial angiography.

A Randomized Comparison of Radial Artery Intimal Hyperplasia Following Distal Versus Proximal Transradial Access for Coronary Angiography: PRESERVE RADIAL

BACKGROUND

Distal transradial access (dTRA) is an alternative to conventional forearm transradial access (fTRA) for coronary angiography (CAG). Differences in healing of the radial artery (RA) in the forearm have not been evaluated between these 2 access strategies. We sought to compare the mean difference in forearm RA intimal-medial thickening (IMT) in patients randomized to dTRA versus fTRA.

METHODS AND RESULTS

In this single-center randomized clinical trial, 64 patients undergoing nonemergent CAG were randomized (1:1) to dTRA versus fTRA. Ultra-high-resolution (55-MHz) vascular ultrasound of the forearm and distal RA was performed pre-CAG and at 90 days. The primary end point was the mean change in forearm RA IMT. Secondary end points included procedural characteristics, vascular injury, RA occlusion, and ipsilateral hand pain and function. Baseline demographics and clinical characteristics, mean forearm RA IMT, and procedural specifics were similar between the dTRA and fTRA cohorts. There was no difference in mean change in forearm RA IMT between the 2 cohorts (0.07 versus 0.07 mm; P=0.37). No RA occlusions or signs of major vascular injury were observed at 90 days. Ipsilateral hand pain and function (Borg pain scale score: 12 versus 11; P=0.24; Disabilities of the Arm, Shoulders, and Hand scale score: 6 versus 8; P=0.46) were comparable.

CONCLUSIONS

Following CAG, dTRA was associated with no differences in mean change of forearm RA IMT, hand pain, and function versus fTRA for CAG. Further investigation is warranted to elucidate mechanisms and predictors of RA healing and identify effective strategies to preserving RA integrity for repeated procedures.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT04801901.

Development and validation of a nomogram for predicting difficult radial artery cannulation in adult surgical patients

Background

Radial artery cannulation is an invasive procedure commonly performed in patients in the perioperative time, in the intensive care unit, and in other critical care settings. The current study aimed to explore the preoperative risk factors associated with difficult radial artery cannulation and develop a nomogram model for adult patients undergoing major surgery. This nomogram may optimize preoperative clinical decision-making, thereby reducing the number of puncture attempts and preventing associated complications.

Methods

This was a single-center prospective cohort study. Between December 2021 and May 2022, 530 adult surgical patients were enrolled. The patients were randomized into the training and validation cohorts at a ratio of 8:2. Radial artery cannulation was performed before the induction of anesthesia. Univariate and multivariate logistic regression analyses were performed to identify variables that were significantly associated with difficult radial artery cannulation. These variables were then incorporated into the nomogram. The discrimination and calibration abilities of the nomogram were assessed.

Results

One hundred and seventy-three (41.7 %) patients in the training cohort had difficult radial artery cannulation. Based on multivariate analysis, the independent risk factors were wrist circumference, anatomical abnormalities, BMI <18.5 kg/m2, grade II hypertension, hypotension, and history of chemotherapy and stroke. The concordance indices were 0.765 (95 % confidence interval [CI]: 0.719-0.812) and 0.808 (95 % CI: 0.725-0.890) in the training and validation cohorts, respectively. The calibration curve showed good agreement between the actual and predicted risks.

Conclusions

A preoperative predictive model for difficult radial artery cannulation in adult patients undergoing surgery was developed and validated. This model can provide reliable data for optimizing preoperative clinical decision-making.

What Factors Are Associated With Arterial Line-Related Limb Ischemia in Patients on Extracorporeal Membrane Oxygenation? A Single-Center Retrospective Cohort Study

OBJECTIVES

The primary purpose of this study was to identify factors associated with the development of arterial line-related limb ischemia in patients on extracorporeal membrane oxygenation (ECMO). The authors also sought to characterize and report the outcomes of patients who developed arterial line-related limb ischemia.

DESIGN

Retrospective cohort study.

SETTING

A single academic tertiary referral ECMO center.

PARTICIPANTS

Consecutive patients who were treated with ECMO over 6 years.

INTERVENTIONS

Use of arterial line.

MEASUREMENTS AND MAIN RESULTS

A total of 278 consecutive ECMO patients were included, with 19 (7%) patients developing arterial line-related limb ischemia during the ECMO run. Postcannulation Sequential Organ Failure Assessment (SOFA) (adjusted odds ratio [aOR] 1.20, 95% CI 1.08-1.32), Acute Physiology and Chronic Health Evaluation-II (aOR 0.84, 95% CI 0.74-0.95), and adjusted Vasopressor Dose Equivalence (aOR 1.03, 95% CI 1.01-1.05) scores were independently associated with the development of arterial line-associated limb ischemia. A SOFA score of ≥17 at the time of ECMO cannulation had an 80% sensitivity and 87% specificity for predicting arterial line-related limb ischemia.

CONCLUSIONS

Arterial line-related limb ischemia is much more common in ECMO patients than in the typical intensive care unit setting. The SOFA score may be useful in identifying which patients may be at risk for arterial line-related limb ischemia. As this was a single-center retrospective study, these results are inherently exploratory, and prospective multicenter studies are necessary to validate these results.

A Randomized Comparison of Radial Artery Intimal Hyperplasia Following Distal vs. Proximal Transradial Access for Coronary Angiography: PRESERVE RADIAL Trial

Background

Distal transradial access (dTRA) is an alternative to conventional forearm transradial access (fTRA) for coronary angiography (CAG). Differences in healing of the radial artery in the forearm (FRA) have not been evaluated between these 2 access strategies. We sought to compare FRA intimal-medial thickening (IMT) in patients randomized to dTRA vs. fTRA for CAG.

Methods and Results

Sixty-four consecutive patients undergoing non-emergent CAG were randomized (1:1) to dTRA vs. fTRA. Ultrahigh resolution (55 MHz) vascular ultrasound) of the FRA and distal RA was performed pre-CAG and at 90 days. Primary endpoint was 90-day FRA IMT. Secondary endpoints included procedural characteristics, vascular injury, RA occlusion and ipsilateral hand pain and function. Baseline demographics and clinical characteristics, mean FRA IMT, time to RA access, procedure time, and radiation exposure were similar between the dTRA and fTRA cohorts. There were no between group differences in 90-day FRA IMT (0.37 mm vs 0.38 mm, respectively; p =0.73). No RA occlusions or signs of major vascular injury were observed at 90 days. Ipsilateral hand pain and function (Borg pain scale:12 vs 11, p =0.24; DASH scores: 6 vs 8, p =0.46) were comparable.

Conclusions

In this single center randomized clinical trial, similar patterns of FRA vascular healing at 90 days, procedural results as well as hand pain and function were observed following dTRA vs. fTRA for CAG. Further investigation is warranted to better understand the mechanistics and predictors of RA healing and to identify strategies aimed at preserving RA integrity for future procedures.

What is New?

DTRA has been proposed as an alternative to traditional fTRA in the wrist for CAG and PCI because of ergonomic and post-procedural recovery benefits to the patient, as well as potential reductions in occlusion of the FRA.There are gaps in knowledge, however, regarding potential differences in remodeling of the FRA in patients undergoing dTRA versus fTRA.In this randomized clinical trial, there were no differences in IMT and patterns of vascular injury and healing, using ultrahigh resolution (55 MHz) ultrasound, at 90 days in patients randomized to dTRA or FTRA for elective and non-emergent CAG and PCI.

What Are the Clinical Implications

Our findings highlight the need for further inquiry through large multicenter randomized clinical trials to better the understand the mechanistics and predictors of IMT and to identify strategies to mitigate the adverse effects of vessel remodeling in patients undergoing TRA across the entire severity spectrum of cardiovascular disease.

A Review of Epidermal Flexible Pressure Sensing Arrays

In recent years, flexible pressure sensing arrays applied in medical monitoring, human-machine interaction, and the Internet of Things have received a lot of attention for their excellent performance. Epidermal sensing arrays can enable the sensing of physiological information, pressure, and other information such as haptics, providing new avenues for the development of wearable devices. This paper reviews the recent research progress on epidermal flexible pressure sensing arrays. Firstly, the fantastic performance materials currently used to prepare flexible pressure sensing arrays are outlined in terms of substrate layer, electrode layer, and sensitive layer. In addition, the general fabrication processes of the materials are summarized, including three-dimensional (3D) printing, screen printing, and laser engraving. Subsequently, the electrode layer structures and sensitive layer microstructures used to further improve the performance design of sensing arrays are discussed based on the limitations of the materials. Furthermore, we present recent advances in the application of fantastic-performance epidermal flexible pressure sensing arrays and their integration with back-end circuits. Finally, the potential challenges and development prospects of flexible pressure sensing arrays are discussed in a comprehensive manner.

Rationale and Design of the Rivaroxaban Post-Transradial Access for the Prevention of Radial Artery Occlusion Trial (CAPITAL-RAPTOR)

INTRODUCTION

Transradial access (TRA) has rapidly emerged as the preferred vascular access site for coronary angiography and percutaneous coronary intervention. Radial artery occlusion (RAO) remains as an important complication of TRA as it precludes future ipsilateral transradial procedures. While intraprocedural anticoagulation has been studied extensively, the definitive role of postprocedural anticoagulation has not yet been established.

METHODS AND ANALYSIS

The Rivaroxaban Post-Transradial Access for the Prevention of Radial Artery Occlusion trial is a multicentre, prospective, randomised, open-label, blinded-endpoint design study investigating the efficacy and safety of rivaroxaban to reduce the incidence of RAO. Eligible patients will undergo randomisation to receive either rivaroxaban 15 mg once daily for 7 days or to no additional postprocedural anticoagulation. Doppler ultrasound to assess radial artery patency will be performed at 30 days.

ETHICS AND DISSEMINATION

The study protocol has been approved by the Ottawa Health Science Network Research Ethics Board (approval number 20180319-01H). The study results will be disseminated via conference presentations and peer-reviewed publications.

TRIAL REGISTRATION NUMBER

NCT03630055.

Lower Patient Height and Weight Are Predisposing Factors for Complex Radial Arterial Catheterization

Background: Radial artery (RA) catheterization for invasive blood pressure monitoring is often performed via palpation, and an ultrasound is used secondarily only in case of multiple unsuccessful attempts. Although more elaborate, it has been shown that primary ultrasound-guided catheterization may be advantageous compared with palpation. The aim of this study was to identify factors associated with difficult RA catheterization. Methods: Left RA ultrasound assessments were performed in patients with indicated invasive blood pressure monitoring the day before surgery. RA catheterization was performed by personnel blinded to the ultrasound results. Based on the number of attempts needed for successful catheter placement, the cohort was divided into uncomplicated (group 1) and difficult (more than one attempt, group 2) catheterization cases. Cases subjected to primary ultrasound were excluded from the analysis. Results: Body weight, height and surface area (BSA) of patients in group 2 (n = 16) were significantly lower than those of patients in group 1 (n = 25), and internal RA diameters were significantly smaller in group 2 patients. In the whole cohort, BSA was significantly associated with distal and proximal internal RA diameters. In contrast, no differences were observed in the skin-to-artery distance, the longitudinal axis deviation (kinking) or blood flow velocity. Median time to successful catheterization was 77 (47–179) s. Prolonged time needed for cannulation was significantly associated with lower body weight, BMI and BSA, and with reduced distal and proximal internal RA diameter. Conclusions: RA catheterization performed through pulse palpation may be difficult, especially in adult patients with lower body weight and height, due to reduced arterial diameters. Initial use of ultrasound in these patients may reduce first-attempt failure, preventing procedural delays and patient discomfort.

Comparison of Safety of RADial comPRESSion Devices: A Multi-Center Trial of Patent Hemostasis following Percutaneous Coronary Intervention from Conventional Radial Access (RAD-PRESS Trial)

Although radial access is the current gold standard for the implementation of percutaneous coronary interventions (PCI), post-procedural radial compression devices are seldom compared with each other in terms of safety or efficacy. Our group aimed to compare a cost effective and potentially green method to dedicated radial compression devices, with respect to access site complications combined in a device oriented complex endpoint (DOCE), freedom from which served as our primary endpoint. Patients undergoing PCI were randomized to receive either the cost effective or a dedicated device, either of which were removed using patent hemostasis. Twenty-four hours after the procedure, radial artery ultrasonography was performed to evaluate the access site. The primary endpoint was assessed using a non-inferiority framework with a non-inferiority margin of five percentage points, which was considered as the least clinically meaningful difference. The cost-effective technique and the dedicated devices were associated with a comparably low rate of complications (freedom from DOCE: 83.3% vs. 70.8%, absolute risk difference: 12.5%, one-sided 95% confidence interval (CI): 1.11%). Composition of the DOCE (i.e., no complication, hematoma, pseudoaneurysm, and radial artery occlusion) and compression time were also assessed in superiority tests as secondary endpoints. Both the cost-effective technique and the dedicated devices were associated with comparably low rates of complications: p = 0.1289. All radial compression devices performed similarly when considering the time to complete removal of the respective device (120.0 (inter-quartile range: 100.0-142.5) for the vial vs. 120.0 (inter-quartile range: 110.0-180) for the dedicated device arm, with a median difference of [95% CI]: 7.0 [-23.11 to 2.00] min, p = 0.2816). In conclusion, our cost-effective method was found to be non-inferior to the dedicated devices with respect to safety, therefore it is a safe alternative to dedicated radial compression devices, as well as seeming to be similarly effective.

Effect of Different Anthropometric Body Indexes on Radiation Exposure in Patients Undergoing Cardiac Catheterisation and Percutaneous Coronary Intervention

Background: Patient factors, such as sex and body mass index (BMI), are known to influence patient radiation exposure. Body surface area (BSA) and its association with patient radiation exposure has not been well studied. Methods and Results: We analysed height, weight, BMI and BSA in consecutive patients undergoing cardiac catheterisation and percutaneous coronary intervention (PCI) at a high-volume Australian centre between September 2016 and April 2020 to assess their association with dose–area product (DAP, Gycm²). The mean age of the cohort was 64.5 ± 12.3 years with males comprising 68.8% (n = 8100, 5124 diagnostic cardiac catheterisation cases and 2976 PCI cases). Median male BMI was 28.4 kg/m² [IQR 25.2–32.1] versus 28.8 kg/m² [24.7–33.7] for females, p = 0.01. Males had higher BSA (2.0 ± 0.2 m²) than females (1.78 ± 0.2 m²), p = 0.001. Each 0.4 m² increase in BSA conferred a 1.32x fold change in DAP (95% CI 1.29–1.36, p ≤ 0.001). Each 5 kg/m² increase in BMI was linked to a 1.13x DAP fold change (1.12–1.14, p ≤ 0.001). Male sex conferred a 1.23x DAP fold change (1.20–1.26, p ≤ 0.001). Multivariable modelling with BMI or BSA explained 14% of DAP variance (R² 0.67 vs. 0.53 for both, p ≤ 0.001). Conclusions: BSA is an important anthropometric measure between the sexes and a key predictor of radiation dose and radiation exposure beyond sex, BMI, and weight.

Assessment and comparison of distal radial artery diameter in anatomical snuff box with conventional radial artery before coronary catheterization

Background

The distal radial artery (dRA) approach at anatomical snuff box has gained attention of the interventional cardiologist in last few years. The procedural success rate by this novel approach depends on size of the radial artery and therefore the study was planned to study the size of distal radial artery.

Methods

Total of 1004 patients of >18 years of age undergoing coronary catheterization were included in the study. The vessel diameter was measured from media to media in the anatomical snuff box a day prior to coronary catheterization.

Results

The mean diameter of right radial artery at conventional access site was 2.56 ± 0.35 mm and at distal access site 2.23 ± 0.39 mm (p < 0.001). Females had significantly smaller radial artery diameter as compared to males at right conventional access site (2.42 ± 0.36 mm vs 2.60 ± 0.34 mm; p < 0.001) and distal access site (2.09 ± 0.38 mm vs 2.27 ± 0.39 mm; p < 0.001). The diameter of the right dRA was not significantly correlated with age (r² linear = 0.002, p = 0.0475) but was positively correlated with height and weight (r² linear = 0.076, p = <0.001 and r² linear = 0.005, p = <0.001) and negatively correlated with BMI (r² linear = 0.076, p = 0.519).

Conclusions

This study has shown the size of right dRA 2.27 + 0.39 mm in males and 2.09 + 0.38 mm in females. Diabetes, hypertension, height and weight are important predictors of dRA diameter.

Toward a Better Understanding of Sex- and Gender-Related Differences in Endovascular Stroke Treatment: A Scientific Statement From the American Heart Association/American Stroke Association

There are many unknowns when it comes to the role of sex in the pathophysiology and management of acute ischemic stroke. This is particularly true for endovascular treatment (EVT). It has only recently been established as standard of care; therefore, data are even more scarce and conflicting compared with other areas of acute stroke. Assessing the role of sex and gender as isolated variables is challenging because they are closely intertwined with each other, as well as with patients' cultural, ethnic, and social backgrounds. Nevertheless, a better understanding of sex- and gender-related differences in EVT is important to develop strategies that can ultimately improve individualized outcome for both men and women. Disregarding patient sex and gender and pursuing a one-size-fits-all strategy may lead to suboptimal or even harmful treatment practices. This scientific statement is meant to outline knowledge gaps and unmet needs for future research on the role of sex and gender in EVT for acute ischemic stroke. It also provides a pragmatic road map for researchers who aim to investigate sex- and gender-related differences in EVT and for clinicians who wish to improve clinical care of their patients undergoing EVT by accounting for sex- and gender-specific factors. Although most EVT studies, including those that form the basis of this scientific statement, report patient sex rather than gender, open questions on gender-specific EVT differences are also discussed.

Spatiotemporal Measurement of Arterial Pulse Waves Enabled by Wearable Active-Matrix Pressure Sensor Arrays

Wearable pressure sensors have demonstrated great potential in detecting pulse pressure waves on the skin for the noninvasive and continuous diagnosis of cardiac conditions. However, difficulties lie in positioning conventional single-point sensors on an invisible arterial line, thereby preventing the detection of adequate signal amplitude for accurate pulse wave analysis. Herein, we introduce the spatiotemporal measurements of arterial pulse waves using wearable active-matrix pressure sensors to obtain optimal pulse waveforms. We fabricate thin-film transistor (TFT) arrays with high yield and uniformity using inkjet printing where array sizes can be customizable and integrate them with highly sensitive piezoresistive sheets. We maximize the pressure sensitivity (16.8 kPa^-1) and achieve low power consumption (10¹ nW) simultaneously by strategically modulating the TFT operation voltage. The sensor array creates a spatiotemporal pulse wave map on the wrist. The map presents the positional dependence of pulse amplitudes, which allows the positioning of the arterial line to accurately extract the augmentation index, a parameter for assessing arterial stiffness. The device overcomes the positional inaccuracy of conventional single-point sensors, and therefore, it can be used for medical applications such as arterial catheter injection or the diagnosis of cardiovascular disease in daily life.

[Transradial approach in neuroendovascular procedures]

OBJECTIVE

To evaluate safety and feasibility of transradial approach for neuroendovascular procedures and to familiarize neurosurgeons and neuroradiologists with the capabilities and limitations of this approach, as well as technical features influencing its effectiveness.

MATERIAL AND METHODS

A retrospective analysis was performed in 270 patients who underwent transradial neuroendovascular procedures between January 2015 and December 2019. Diagnostic and surgical interventions were performed in 203 (75.2%) and 67 (24.8%) patients, respectively. The authors comprehensively describe catheterization technique and choosing the instrument for effective and safe transradial access.

RESULTS

The right vertebral and both common carotid arteries were the most accessible for selective catheterization (100% of cases). The left common carotid artery was catheterized in all cases, the left internal carotid artery - only in 92% of cases. If catheterization of the left vertebral artery was necessary, we used the left-sided radial approach. Conversion to femoral approach was required in 2.6% of cases for the left internal carotid artery disease (n=7). Radial artery occlusion occurred in 3.7% of cases (n=10) and was asymptomatic in all cases. We present a video clip (https://youtu.be/3wZ6O8u-lpk) devoted to various surgical interventions through radial approach.

CONCLUSION

Radial approach is safe and feasible and may be used for neuroendovascular procedures.

Transradial approach and its variations for neurointerventional procedures: Literature review

Background:

The transfemoral approach (TFA) has been the standard in neuroradiology over the years. However, the transradial approach (TRA) and its variants offer several benefits over the TFA.

Methods:

Review of the literature about TRA and its variations. We present our results for different neurointerventional procedures at our institution between January 2018 and December 2019.

Results:

We wrote an educational review describing anatomical and technical aspects, advantages, and complications of this approach. In the past year we increased the percentage of neurointerventional procedures performed through radial or ulnar arteries.

Conclusion:

There are clearly proven benefits of employing a wrist approach in patients for neurointerventional procedures and its utilization should especially be considered on a daily basis.

Slender Sheath/Guiding Catheter Combination vs. Sheathless Guiding Catheter for Acute Coronary Syndrome: A Propensity-Matched Analysis of the Two Devices

A Glidesheath slender (Terumo, Tokyo, Japan) and a sheathless Eaucath guiding catheter (Asahi Intecc, Nagoya, Japan) are two major slender devices utilized in percutaneous coronary intervention (PCI). This study aimed to investigate the differences in access-site complications between these devices in PCI for acute coronary syndrome (ACS). A total of 1108 consecutive patients who underwent transradial PCI for ACS were enrolled. Transradial PCI was performed using either a 7-Fr Glidesheath slender/7-Fr guiding catheter combination (Glidesheath group) or a 7.5-Fr sheathless guiding catheter (Sheathless group); 1 : 1 propensity score matching was performed, and 728 patients (364 in each group) were included in the propensity-matched population. In the matched patients, univariate analysis revealed that the Glidesheath group had less radial artery occlusion (RAO) at 30 days (Glidesheath: 1.4% vs. Sheathless: 4.1%, odds ratio (OR) = 0.33, 95% confidence interval (CI) =  0.12-0.91, p=0.039), whereas no significant between-group differences were observed in severe radial spasm (Glidesheath: 1.4% vs. Sheathless: 1.9%, OR = 0.71, 95% CI = 0.23-2.22, p=0.58) or access-site major bleeding (Glidesheath: 1.4% vs. Sheathless: 1.6%, OR = 0.83, 95% CI = 0.26-2.71, p=1.00). Multivariate analysis revealed that the choice for Glidesheath was significantly associated with less RAO (OR = 0.32, 95% CI = 0.11-0.93, p=0.036). In conclusion, 7-Fr Glidesheath slender/7-Fr guiding catheter combination is obviously more advantageous than 7.5-Fr sheathless guiding catheters for decreased risk of RAO. The potential low risk of RAO in our findings supports the adoption of the 7-Fr Glidesheath slender sheath/7-Fr guiding catheter combination in transradial PCI for ACS.

Transradial access for arteriovenous fistuloplasty in Singapore

BACKGROUND

Endovascular balloon angioplasty is standard therapy for dysfunctional arteriovenous fistula in end-stage renal failure patients on hemodialysis. Venous antegrade or retrograde puncture of the fistula is typically performed to gain access for fistuloplasty. Transradial approach for brachiocephalic or brachiobasilic arteriovenous fistulas offers an alternative method of access with the advantage of addressing multi-focal juxta-anastomotic and venous stenosis from the same approach. We aim to review the efficacy, outcomes and complication rates of transradial access for arteriovenous fistuloplasty among patients in Singapore.

METHODS

A retrospective review of 195 endovascular fistuloplasties from September 2017 to August 2019, at a tertiary university hospital Vascular Surgery unit.

RESULTS

Of 195 fistuloplasties, 43 (22%) were transradial approach (23 brachiocephalic arteriovenous fistulas, 20 brachiobasilic arteriovenous fistulas) in 33 patients (67% male and mean age = 65 years). Of these 43 procedures, 11 (26%) were performed as balloon-assisted maturation fistuloplasties while 32 (74%) were performed for mature arteriovenous fistulas with multi-focal juxta-anastomosis and venous stenosis. Technical success rate was 95% with mean procedure duration at 43.5 ± 14.6 min. Mean pre- and post-fistuloplasty dialysis access flow rates increased from 502 to 952 ml/min (p < 0.001). Post-intervention primary patency was 100%, 66% and 20% at 1, 6 and 12 months, respectively. There were four patients with non-limb-threatening radial artery thrombosis (9.3%) while there was no radial artery pseudoaneurysm or post-procedural bleeding.

CONCLUSION

Transradial approach for arteriovenous fistuloplasty is a safe and feasible option in patients requiring balloon-assisted maturation or with multi-focal juxta-anastomotic and venous stenosis.

Can Children Be Considered for Transradial Interventions?: Prospective Study of Sonographic Radial Artery Diameters

BACKGROUND

Transradial intervention is increasingly replacing approaches, due to lower access complications, cost, and improved patient satisfaction. There are limited supporting data in the pediatric literature, largely due to concerns regarding arterial size. The objective of this study was to measure radial artery diameters in children across all age groups, to establish reference ranges for clinical use.

METHODS

This prospective study was carried out in children ≤18 years of age who underwent ultrasound for measuring radial artery diameters from November 2018 to November 2019. The cohort was divided into age groups: ≤2, 3 to 5, 6 to 8, 9 to 11, 12 to 14, 15 to 18 years, and into pre- and post-adolescent (≥12 years) groups.

RESULTS

One hundred thirty-four children (M:F=63:71) were included, with bilateral measurements resulting in 268 data points. Mean age was 8.9±5.8 years (range, 29 days to 18 years), mean weight 37.2±27.5 kg (range, 1.7-149.1 kg). Mean-corrected radial artery diameter was 1.86±0.44 mm. There was no difference in arterial diameters between males and females (1.90±0.50 versus 1.81±0.53 mm; P=0.73) or between right and left sides (1.87±0.46 versus 1.87±0.47, P=0.98). There was a strong correlation of diameter with age (R=0.75; P<0.00001) and weight (R=0.74; P<0.00001). There was linear increase in arterial growth rates in early childhood, followed by plateauing to adult sizes in adolescents. Inter-reader agreement was 0.95.

CONCLUSIONS

We provide a reference range for radial artery diameters across childhood ages, which can be used for decision-making. This could be the basis for designing a trial of transradial intervention in children, to establish clinical safety and efficacy.

Nursing-led ultrasound to aid in trans-radial access in cardiac catheterisation: a feasibility study

Background

Trans-radial access is increasingly common for cardiac catheterisation. Benefits include reduced bleeding complications, length of hospital stay and costs.

Aims

To determine the feasibility of implementing a nurse-led ultrasound programme to measure radial artery diameter before and after cardiac catheterisation; to determine radial artery occlusion (RAO) rates, risk factors for RAO and predictors of radial artery (RA) diameter.

Method

A prospective observational cohort study design for 100 consecutive patients undergoing cardiac catheterisation, using RA access. Pre- and post-procedural RA diameter were measured using ultrasound, by specialist nurses trained to do so. Logistic regression analyses were performed to determine risk factors for RAO and predictors of RA diameter with results reported as odds ratios (OR) and 95% confidence intervals (CI).

Results

There were no adverse events, supporting the feasibility of nurse led ultrasound programmes. A 4% (n = 4) rate of occlusion was observed. Haemostasis device application time of greater than 190 min was a predictor of RAO (OR 3.12, 95% CI 0.31-31). Male gender and height were predictors for a RA diameter of >2.2 mm.

Conclusions

Nurses can lead the assessment of RA occlusion using ultrasound to enhance planning and care, including monitoring compression times to reduce RAO.

Development of a Multi-Array Pressure Sensor Module for Radial Artery Pulse Wave Measurement

This study proposes a new structure for a pressure sensor module that can reduce errors caused by measurement position and direction in noninvasive radial artery pulse wave measurement, which is used for physiological monitoring. We have proposed a structure for a multi-array pressure sensor with a hexagonal arrangement and polydimethylsiloxane that easily fits to the structure of the radial artery, and evaluated the characteristics and pulse wave measurement of the developed sensor by finite element method simulation, a push–pull gauge test, and an actual pulse wave measurement experiment. The developed sensor has a measuring area of 17.6 × 17.6 mm² and a modular structure with the analog front end embedded on the printed circuit board. The finite element method simulation shows that the developed sensor responds linearly to external pressure. According to the push–pull gauge test results for each channel, there were differences between the channels caused by the unit sensor characteristics and fabrication process. However, the correction formula can minimize the differences and ensure the linearity, and root-mean-squared error is 0.267 kPa in calibrated output. Although additional experiments and considerations on inter-individual differences are required, the results suggested that the proposed multiarray sensor could be used as a radial arterial pulse wave sensor.

RadialFirst in CHIP and Cardiogenic Shock

This article highlights the advantages and disadvantages of transradial arterial (TRA) access for a variety of presentations including acute coronary syndromes; cardiogenic shock; unprotected left main, heavily calcified coronaries; bifurcations; and chronic total occlusions. It includes techniques for overcoming challenges of using TRA access, including spasm and the need for larger bore guides. In addition, the authors review the use of ultrasound for access, percutaneous hemodynamic support via axillary approach, and tips and tricks to performing right heart catheterizations from the antecubital vein.

[Radial approach in the elderly]

Due to the steady increase in life expectancy, the number of patients over 80 years of age proposed for coronary angioplasty is increasing significantly. The elderly patient is a patient at high cardiovascular risk and high risk of bleeding; whose severity of prognosis depends of comorbidities. The radial approach presents particularities and technical difficulties that have to be known in this part of the population, but reduce vascular and hemorrhagic complications, as well as mortality. Because of greater safety, the radial approach is therefore the first choice for the elderly.

Sheath size, radial occlusion, and ethnicity: Real or confounded?

Japanese participants experienced higher incidence of radial artery occlusion when compared to non-Japanese participants. The use of 6Fr Slender sheath was inferior for radial artery occlusion than 5Fr sheath in Japanese, but no different in non-Japanese participants. Is not clear if this apparent ethnical interaction is real versus confounded, warranting more research in the area.

Prevention of Radial Artery Occlusions Following Coronary Procedures: Forward and Backward Steps in Improving Radial Artery Patency Rates

Radial artery (RA) occlusion (RAO) remains the Achilles heel of transradial coronary procedures. Although of silent nature, RAO is relatively frequent, results in graft shortage for future coronary artery bypass surgery, and may occur even after short-lasting, 5F coronary angiography (CAG). The most frequent predictors of RAO are RA size, body size, female gender, and periprocedural anticoagulation intensity. Methods to detect RAO are variable, of which the Barbeau test and ultrasonography have similar diagnostic accuracy. Data indicate that late RAO recanalization may occur. Meticulous handling of RA and the use of appropriate hemostatic devices and techniques along with sufficient heparin dose appear important measures to reduce RAO rates. Recent contradictory studies indicate that the decreasing incidence of RAO overtime is not as uniform as previously thought. In 2 meta-analyses, the benefit of higher over lower anticoagulation intensity became evident. As “it may all be appropriate anticoagulation” for a simplified approach against RAO, the results of an ongoing trial comparing 100 with 50 IU/kg body weight in transradial CAG are eagerly awaited.

Impact of sheath size and hemostasis time on radial artery patency after transradial coronary angiography and intervention in Japanese and non-Japanese patients: A substudy from RAP and BEAT (Radial Artery Patency and Bleeding, Efficacy, Adverse evenT) randomized multicenter trial

Background

During transradial (TR) access, it remains unclear whether differences in baseline patients characteristics and hemostasis care impact the rate of radial artery occlusion (RAO). We sought to compare the rate of RAO after TR access with the 6 French(Fr) Glidesheath Slender (GSS6Fr, Terumo, Japan) or a standard 5 Fr sheath in Japanese and non‐Japanese patients.

Methods and Results

The Radial Artery Patency and Bleeding, Efficacy, Adverse evenT (RAP and BEAT) trial randomized 1,836 patients undergoing TR coronary angiography and/or interventions to receive the GSS6Fr or the standard 5 Fr Glidesheath (GS5Fr, Terumo, Japan). Out of this study population, 1,087 were Japanese patients and 751 non‐Japanese patients. The overall incidence of RAO was significantly higher in Japanese patients (3.6% vs. 1.2%, P = 0.002). Use of GSS6Fr was associated with higher rates of RAO than GS5Fr in Japanese patients (5% vs. 2.2%, P = 0.02) and with similar RAO rates in non‐Japanese patients (1.3 vs. 1.1%, P = 1). The mean hemostasis time was significantly longer in Japanese patients (378 ± 253 vs. 159 ± 136 min, P < 0.001) and more Japanese patients had a hemostasis time of more than 6 hr (16.2% vs. 4.9%, P < 0.0001). Longer hemostasis time was an independent predictor of RAO (OR per additional hour 1.070, 95% CI 1.008–1.136, P = 0.03).

Conclusions

Use of GSS6Fr was associated with a higher rate of RAO than a standard 5 Fr sheath in Japanese patients but not in non‐Japanese patients. Whether improvement in post‐procedural care and reduced hemostasis time could impact the incidence of RAO in Japanese patients should be further assessed.

Complications Following Transradial Cerebral Angiography : An Ultrasound Follow-Up Study

OBJECTIVE

The feasibility and usefulness of transradial catheterization for coronary and neuro-intervention are well known. However, the anatomical change in the catheterized radial artery (RA) is not well understood. Herein, we present the results of ultrasonographic observation of the RA after routine transradial cerebral angiography (TRCA).

METHODS

Patients who underwent routine TRCA with pre- and post-procedure Doppler ultrasonography (DUS) of the catheterized RA were enrolled. We then recorded and retrospectively reviewed the diameter and any complicated features of the RA observed on DUS, and the factors associated with the diameter and complications were analyzed.

RESULTS

A total of 223 TRCAs across 181 patients were enrolled in the current study. The mean RA diameter was 2.48 mm and was positively correlated with male gender (p<0.001) and hypertension (p<0.002). The median change in diameter after TRCA was less than 0.1 mm (range, -1.3 to 1.2 mm) and 90% of changes were between -0.8 and +0.7 mm. Across 228 procedures, there were 12 cases (5.3%) of intimal hyperplasia and 22 cases (9.6%) of asymptomatic local vascular complications found on DUS. Patients with abnormal findings on the first procedure had a smaller pre-procedural RA diameter than that of patients without findings (2.26 vs. 2.53 mm, p=0.0028). There was no significant difference in the incidence of abnormal findings for the first versus subsequent procedures (p=0.68).

CONCLUSION

DUS identified the pre- and post-procedural diameter and local complications of RA. Routine TRCA seems to be acceptable with regard to identifying local complications and changes in RA diameter.

First-in-Human Study of Acoustic Angiography in the Breast and Peripheral Vasculature

Screening with mammography has been found to increase breast cancer survival rates by about 20%. However, the current system in which mammography is used to direct patients toward biopsy or surgical excision also results in relatively high rates of unnecessary biopsy, as 66.8% of biopsies are benign. A non-ionizing radiation imaging approach with increased specificity might reduce the rate of unnecessary biopsies. Quantifying the vascular characteristics within and surrounding lesions represents one potential target for assessing likelihood of malignancy via imaging. In this clinical note, we describe the translation of a contrast-enhanced ultrasound technique, acoustic angiography, to human imaging. We illustrate the feasibility of this technique with initial studies in imaging the hand, wrist and breast using Definity microbubble contrast agent and a mechanically steered prototype dual-frequency transducer in healthy volunteers. Finally, this approach was used to image pre-biopsy Breast Imaging Reporting and Data System (BI-RADS) 4 and 5 lesions <2 cm in depth in 11 patients. Results indicate that sensitivity and spatial resolution are sufficient to image vessels as small as 0.2 mm in diameter at depths of ~15 mm in the human breast. Challenges observed include motion artifacts, as well as limited depth of field and sensitivity, which could be improved by correction algorithms and improved transducer technologies.

Risk Factors for Radial-to-Femoral Artery Pressure Gradient in Patients Undergoing Cardiac Surgery With Cardiopulmonary Bypass

OBJECTIVE

To identify risk factors associated with radial-to-femoral pressure gradient during cardiac surgery with cardiopulmonary bypass (CPB).

DESIGN

This is a retrospective, observational study.

SETTING

Single specialized cardiothoracic hospital in Montreal, Canada.

PARTICIPANTS

Consecutive patients that underwent heart surgery with CPB between 2005 and 2015 (n = 435).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A radial-to-femoral pressure gradient occurred in 146 patients of the 435 patients (34%). Based on the 10,000 bootstrap samples, simple logistic regression models identified the 17 most commonly significant variables across the bootstrap runs. Using these variables, a backward multiple logistic model was performed on the original sample and identified the following independent variables: body surface area (m²) (odds ratio [OR] 0.08, 95% confidence interval [CI] 0.030-0.232), clamping time (minutes) (OR 1.01, 95% CI 1.007-1.018), fluid balance (for 1 liter) (OR 0.81, 95% CI 0.669-0.976), and preoperative hypertension (OR 1.801, 95% CI 1.131-2.868).

CONCLUSION

A radial-to-femoral pressure gradient occurs in 34% of patients during cardiac surgery. Patients at risk seem to be of smaller stature, hypertensive, and undergo longer and more complex surgeries.

Radial Artery and Ulnar Artery Occlusions Following Coronary Procedures and the Impact of Anticoagulation: ARTEMIS (Radial and Ulnar ARTEry Occlusion Meta-AnalysIS) Systematic Review and Meta-Analysis

Background

Incidence of radial artery occclusions (RAO) and ulnar artery occclusions (UAO) in coronary procedures, factors predisposing to forearm arteries occlusion, and the benefit of anticoaggulation vary significantly in existing literature. We sought to determine the incidence of RAO/UAO and the impact of anticoagulation intensity.

Methods and Results

Meta‐analysis of 112 studies assessing RAO and/or UAO (N=46 631) were included. Overall, there was no difference between crude RAO and UAO rates (5.2%; 95% confidence interval [CI], 4.4–6.0 versus 4.0%; 95% CI, 2.8–5.8; P=0.171). The early occlusion rate (in‐hospital or within 7 days after procedure) was higher than the late occlusion rate. The detection rate of occlusion was higher with vascular ultrasonography compared with clinical evaluation only. Low‐dose heparin was associated with a significantly higher RAO rate compared with high‐dose heparin (7.2%; 95% CI, 5.5–9.4 versus 4.3%; 95% CI, 3.5–5.3; Q=8.81; P=0.003). Early occlusions in low‐dose heparin cohorts mounted at 8.0% (95% CI, 6.1–10.6). The RAO rate was higher after diagnostic angiographies compared with coronary interventions, presumably attributed to the higher intensity of anticoagulation in the latter group. Hemostatic techniques (patent versus nonpatent hemostasis), geography (US versus non‐US cohorts) and sheath size did not impact on vessel patency.

Conclusions

RAO and UAO occur with similar frequency and in the order of 7% to 8% when evaluated early by vascular ultrasonography following coronary procedures. More‐intensive anticoagulation is protective. Late recanalization occurs in a substantial minority of patients.

Racial and Gender Differences in Arterial Anatomy of the Arm

Prior studies have shown racial and gender differences with respect to maturation of arteriovenous fistulas. Women and minorities have lower maturation rates for unclear reasons. Small arterial diameter and high brachial artery bifurcation (HBB) are also implicated in reduced maturation rates. We sought to correlate differences in upper extremity arterial anatomy to race and gender. All upper extremity vascular mapping ultrasounds from 2013 to 2014 were retrospectively reviewed. A total of 509 arms in 284 patients were evaluated. Men had significantly higher mean arterial diameters than women at the elbow brachial (4.7 vs 3.9 mm, P < 0.01) and wrist radial arteries (2.1 vs 1.9 mm, P = 0.03). There were 20 (7%) patients with HBB of at least one arm, and 7 (2.5%) patients with bilateral HBB. African-American patients had significantly higher rates of both unilateral HBB (15.9% vs 5.4%, P = 0.02) and bilateral HBBs (9.1% vs 1.3%, P = 0.01). In conclusion, men had significantly larger arteries than women, and African-Americans had a higher rate of HBB than non-African-Americans. Consideration should be given for routine preoperative ultrasound to assess arterial anatomy before arteriovenous fistulas creation, particularly in women and in African-Americans.

Ulnar artery: The Ulysses ultimate resort for coronary procedures

Despite the increasing worldwide adoption of the transradial access site, the ulnar artery (UA) only very infrequently serves as a primary option for coronary procedures. In contrast to the uncertainty surrounding previous reports regarding the feasibility and safety, recent data from larger registries and randomized trials provide more conclusive evidence that the transulnar route may be safely selected as an alternative arterial access approach. However, a default transulnar strategy appears time-consuming and is associated with higher crossover rates compared with the radial artery (RA). Once arterial access is obtained, the likelihood of a successful coronary procedure is high and similar between the two forearm arteries. The UA has similar flow-mediating vasodilating properties with and seems at least as vulnerable as the RA with regard to incident occlusion, with UA occlusion (UAO) rates being probably higher than previously anticipated. A learning curve effect may not be apparent for crossover rates among experienced radialists, but increasing experience is associated with reduction in the fluoroscopy time, contrast volume and frequency of large hematoma formation. The UA may represents an important alternative access site for coronary procedures, and experienced radial operators should obtain additional skills to perform the transulnar approach. Nevertheless, in view of this method's lower feasibility compared to the RA, an initial ulnar access strategy should be reserved for carefully selected patients to ensure satisfactory cannulation rates.

Radial artery occlusion after transradial approach to cardiac catheterization

Radial artery occlusion (RAO) is the most common complication of the transradial approach (TRA) to cardiac catheterization, with a reported incidence between 0.8 % and 30 %. RAO is likely the result of acute thrombus formation and complicated by neointimal hyperplasia. Most RAO are asymptomatic with rare cases of acute hand or digit ischemia reported in the literature. The role of testing for dual circulation to the hand in determining the safety of TRA as it relates to symptomatic RAO is controversial; however, modifiable risk factors like low sheath-to-artery ratio, adequate anticoagulation, and non-occlusive ("patent") hemostasis are likely to prevent RAO. This review examines the incidence of RAO, potential mechanisms leading to RAO, and strategies to prevent and treat RAO.

Cephalic vein and radial artery diameter in formation of radiocephalic arteriovenous fistula: a systematic review

PURPOSE

The aim of this study is to determine the optimal range of cephalic vein and radial artery diameter following preoperative duplex imaging to enhance maturation and primary patency of Brescia-Cimino radiocephalic arteriovenous fistula.

METHODS

A systematic review and meta-aggregation of literature from 1966 to January 2015 in English language and adult subjects in Pubmed, OVID, CINHAL and Cochrane database was conducted.

RESULTS

This search produced a total of thirty-six (n = 36) articles. Following the application of recruitment criteria, only twelve articles (n = 12) were found eligible. Their quality was assessed by Oxford Critical Appraisal skills Programme (CASP) and their recommendation for practice was examined through National Institute for Health and Care Excellence (NICE).

CONCLUSIONS

The current literature suggests that the optimal range of radial artery for maximum performance (maturation and primary patency) of RCAVF is at least 2 mm (level 2, grade a). The cephalic vein diameter of at least 2 mm (non-augmented) can result in best maturation and primary patency outcomes (level 2, grade a) and threshold below 1.5 mm is not advocated (level 2, grade b).