title: Optimising Radial Access Site Management in Patients Undergoing Transradial Cardiac Procedures
Creators: name: Proscia, Claudio
Publisher: name: University of Liverpool Repository
Year: 2024

description: Objectives:
This project presents novel and original research seeking to develop the management of the radial arterial access site in coronary interventions. It aims to improve the procedural success rate, enhance the patient experience, and reduce access site complications, the use of healthcare resources, and associated costs.
Background:
Transradial access is currently the recommended access in cardiovascular interventions, and it has significant clinical, logistical, and financial benefits over the traditional femoral route. Despite consensus documents on transradial access, the optimal management of the access site remains a significant gap in our knowledge. The physics of extrinsic compression governing the performance of radial compression devices has not been fully explored. In small, randomised trials, using haemostatic dressings (HD) with radial compression devices has significantly shortened the post-procedural haemostatic times. However, data from large randomised controlled trials (RCTs) are scarce. Finally, the radial artery can be a challenging target for successful puncture and cannulation due to its small calibre and tendency to spasm. There is a need for non-pharmacological strategies that can facilitate radial puncture and cannulation, thus improving transradial access success rates.
Methods:
Following a series of three preliminary tests that assessed the feasibility of electronic data recording and the ideal level of securement of the market-leading radial device (TR Band®), three separate in vitro studies explored the change in the TR Band compression force (CF) associated with variation in band tightness, incremental inflations and deflations, duration of inflation, and using a haemostatic dressing underneath the band. Changes in the TR Band balloon contact area at different inflation levels were also assessed. These studies consisted of a series of tests performed using the technology provided by the Biolife LCC laboratory (Sarasota, FL), which included a load cell mounted on a silicone mannequin arm for continuous electronic data collection.
I performed an RCT (“Assessment of Radial Artery Complications Whilst Achieving Rapid Haemostasis” [ARCH] trial) evaluating a radial haemostatic dressing, randomising patients to three radial compression strategies with the TR Band: 120-min with conventional dressing (C2) vs 60-min with conventional dressing (C1) vs 60-min with an HD (H1). The primary outcome was failure to achieve haemostasis at the planned time. The secondary endpoints included total time-to-final haemostasis (TTH), radial artery occlusion (RAO), puncture-related haematoma and vascular injury requiring repair, and incidence of delayed discharge due to prolongation of radial care. 
Finally, a series of pilot studies explored whether a short period of handgrip exercise (HE) would promote ipsilateral radial artery vasodilation (measured as the change in cross-sectional area, XSA) in healthy volunteers.
Results:
A tighter securement of the TR Band increased the mean CF achieved for a given inflation volume. Adding an HD significantly increased CF independent of band tightness level. Following TR Band inflation, there was an initial rapid fall in the CF followed by a plateau – with a more substantial drop at lower CF levels (2,767-2,631 g [6% drop]; 363-227 g [40%]). Similarly, following TR Band deflation, CF increased spontaneously to reach a plateau - larger increase at lower CF (1,814-1,905 g [3% increase]; 136-272 g [49%]). The post-deflation rebound effect was significantly smaller in the groups with the HD (11% vs 27%, p&lt; 0.001). The TR Band balloon contact area decreased with increasing volume of inflation. 
In the RCT, 2114 patients were randomised to the three strategies (C1=703, C2=703, H1=708). 62% of patients in C1 and 50% in C2 failed to achieve haemostasis at the planned time vs 5.2% in H1. The difference between the haemostatic strategies was statistically significant in all paired comparisons: C1 vs C2 12% (95% CI: 5.8%, 18.2%), OR 1.6, P &lt; 0.0001; C1 vs H1 56.8% (CI 95%: 52.0%, 61.5%), OR 26.7, P &lt; 0.0001; C2 vs H1 44.8% (95% CI: 40.0%, 49.6%), OR 16.7, P &lt; 0.0001. Median [IQR] TTH was 72 mins [68, 81 mins] in H1, 136 mins [80, 189] in C1, and 166 minutes [133, 213] in C2 (P&lt;0.0001). No significant differences were seen in access-site complications, with low rates of haematomas &gt; 5 cm (H1: 2.3%, C1: 1.6%, C2: 2.0%) and RAO (0.4% in H1, 1.0% in C1 and 0.4% in C2). 16.2% of patients in C2 and 15.8% in C1 experienced delayed discharge exclusively due to prolonged radial care vs 2.0% in H1: C1 vs C2 -0.4% (95% CI: -5.1%, 4.2%), OR 1, P = 1.0; C1 vs H1 14% (95% CI: 10%, 17%), OR 9.5, P &lt; 0.0001; C2 vs H1 14% (95% CI: 11%, 18%), OR 9.5, P &lt; 0.0001.
The short period of HE generated maximum vasodilatation of the radial artery within 15 minutes of exercise, with a mean 16-29% XSA increase from baseline, depending on the exercise regime and resistance of the therapy ball used.
Conclusions:
Understanding radial compression mechanisms may help refine haemostasis techniques, increasing the safety and efficacy of current protocols. Using HD allows for more rapid, consistent, and safe haemostasis, improving patient experience and reducing nursing care requirements and the incidence of delayed discharge. Non-pharmacological strategies to generate radial artery vasodilation are feasible and may increase patient comfort and the success rate of transradial access in cardiovascular interventions