Feasibility of Transradial Access Through Chronically Occluded Radial Arteries

Distal Versus Proximal Radial Artery Access for Cardiac Catheterization: 1-Year Outcomes

Transradial access is increasingly utilized in neurointerventional procedures; however, due to the narrow diameter of the radial artery, puncture may induce radial artery spasm, and postoperative radial artery occlusion is a relatively common complication following transradial access. Although often asymptomatic, it poses challenges for subsequent radial artery access. In this instance, the patient experienced proximal radial artery occlusion subsequent to radial artery angiography, coupled with severe stenosis at the origin of the right vertebral artery. The patient strongly preferred radial artery access. Proximal radial artery puncture proved unsuccessful, so after puncturing the distal right radial artery, recanalization of the proximal radial artery was conducted, followed by stent placement in the right vertebral artery. The surgery was successful, and no complications arose postoperatively, offering a reference for future studies on proximal radial artery occlusion, distal radial artery access, and neurointerventional treatment.

Randomized comparison of proximal and distal radial access for coronary angiography and interventions

The present study aimed to quantitatively measure the pressure-derived function of the palmar arch and forearm arterial collateral circulation during transradial access. Palmar arch and forearm collateral function was determined using radial artery pressure signals in the nonobstructed vessel and during brief manual occlusions of the more proximal radial artery and of the radial plus ulnar arteries. Collateral flow index (CFI), the ratio of mean occlusive divided by mean nonocclusive arterial blood pressure, both subtracted by central venous pressure, was determined for CFI during radial artery occlusion (CFIrad) and CFI during radial plus ulnar artery occlusion. Before invasive CFI measurements, arterial palmar arch and forearm function was tested noninvasively by the modified Allen test (MAT). Two hundred fifty patients undergoing transradial access coronary angiography were included in the study. CFIrad was equal to 0.802±0.150 (95% CI, 0.783-0.820). CFI during radial plus ulnar artery occlusion was equal to 0.424±0.188 (95% CI, 0.400-0.447). There was an inverse linear relation between CFIrad and MAT in seconds (s): MAT=64-63×CFIrad ( r2=0.229; P<0.0001). Two hundred eleven patients had a normal and 39 patients an abnormal (>15 seconds) MAT. The group with normal MAT had a CFIrad of 0.830±0.111, and patients with abnormal MAT had a CFIrad of 0.648±0.224 ( P<0.0001). Direct invasive hemodynamic assessment of the palmar arch and forearm arterial function reveals collateral supply to the briefly occluded in comparison to the patent radial artery of 0.802. During external occlusion of both radial and ulnar artery, CFI amounts to an unexpectedly high value of 0.424.

LB-2 | Distal versus Proximal Radial Artery Access for Cardiac Catheterization and Intervention: 1-Year Results of The DIPRA study

The prevalence and implications of radial artery occlusion (RAO) after transradial catheterization are an intensely discussed topic, resulting in numerous preventive strategies such as adjusted anticoagulation, residual-patency hemostasis, or distal puncture site. The present study aimed at assessing an association of palmar arch, in particular radial artery collateral function and RAO after transradial access (TRA) catheterization. Radial artery collateral function was determined using radial artery pressure signals in the nonobstructed vessel and during brief manual occlusion of the more proximal radial artery. Collateral flow index, the ratio of mean occlusive divided by mean nonocclusive arterial blood pressure, both subtracted by central venous pressure, was determined during manual RAO (radial artery collateral flow index [CFIrad]). The presence or absence of RAO was determined by Doppler ultrasound at least 3 months after TRA. A total of 630 patients with TRA coronary angiography underwent palmar arch, that is, radial and radial plus ulnar artery collateral function assessment. CFIrad was equal to 0.808 ± 0.144 (95% confidence interval 0.797 to 0.819). A total of 200 patients underwent Doppler ultrasound examination of their forearm arterial circulation 301 ± 140 days after TRA. Eight (4%) patients showed signs of RAO, 4 of whom (2%) had a complete RAO and 4 (2%) a stenosis above 30%. Patients with RAO showed a higher CFIrad than those without RAO: 0.900 ± 0.074 versus 0.801 ± 0.154 (p=0.006). In conclusion, complete RAO as determined by Doppler ultrasound later than 3 months after TRA is rare (2%). In the long run, RAO appears to be related to a very well-developed radial artery collateral function.

Background: Compared to trans-femoral access (TFA), trans-radial access (TRA) decreased mortality in the 1990s. It became common practice to use proximal radial access (PRA), which is 2-3 cm above the styloid: Radial artery occlusion (RAO) (no pulse + no Doppler), hematoma, and spasm. Although RAO is frequently asymptomatic, it poses a risk of ischemia and restricts future access. Patency is frequently not evaluated after the surgery. Usability of the ulnar artery is impacted by RAO. Due to fewer difficulties than PRA, distal radial artery access (DRA) is increasingly preferred. Assessing the proximal and DRA patency following percutaneous coronary intervention was the goal of this study. Methods: 200 patients who were referred for coronary angiography with potential percutaneous coronary intervention (PCI) via radial artery access were the subjects of this prospective study. Additionally, patients were split into two equal groups: Group I received PCI or coronary angiography (CAG) by proximal radial artery access, and Group II received PCI or CAG via DRA. Results: Overall complication rates, procedural success, and baseline characteristics did not significantly differ between the two groups. However, Group I suffered more radial artery spasm, RAO, and access-site pain, and their first-attempt puncture success was higher, but their hemostasis duration was longer. Group II needed more second tries but had quicker cannulation and hemostasis times. In both groups, patient satisfaction was excellent and comparable. Conclusions: Distal radial access offers a promising alternative to proximal access in coronary procedures, with notable benefits, though wider adoption requires overcoming technical challenges and further validation through large-scale studies.

Background: Recanalization of occluded radial arteries via distal transradial access is being increasingly performed. However, few studies have focused on the long-term follow-up of patients undergoing this procedure. This study investigated the long-term effects of recanalization of the occluded radial artery on vascular and hand function. Methods: In this retrospective cohort study, long-term follow-up of patients who had successfully undergone recanalization of an occluded radial artery was conducted over six months using a portable ultrasound and a hand function test kit. Results: A total of 40 patients were included in the study; 57.5% (23/40) were male, and the mean age was 65.9 years. During the follow-up period of 29.6 ± 15.4 months, 72.5% (29/40) of patients experienced radial artery reocclusion, of which 82.8% (24/29) had distal radial artery occlusion. A history of coronary heart disease (82.76% vs. 18.18%, P &lt; 0.001) and multiple interventions via the radial artery (34.48% vs. 0.0%, P = 0.038) were more prevalent in the reocclusion group than in the patency group. The follow-up ultrasound results indicated that the diameters of the proximal and distal radial arteries in the patency group was significantly greater than those in the reocclusion group. In addition, the diameters of the proximal and distal radial arteries on the patent side were also significantly larger than those on the reocclusion side. The intima thickness of the proximal radial artery on the reocclusion side was significantly greater than that on the contralateral side (0.44 ± 0.08 mm vs. 0.34 ± 0.05 mm, P = 0.003). There were no significant differences in the Quick DASH scale score or hand sensorimotor function between the reocclusion group and the patency group. Two-point discrimination on the reocclusion side was worse than that on the patent side (11.30 ± 3.25 mm vs. 10.39 ± 3.27 mm, P = 0.035). Conclusion: It is technically safe and feasible to recanalize an occluded radial artery via the distal radial artery. However, the long-term reocclusion rate is high after recanalization. More importantly, this procedure can lead to distal radial artery occlusion. Hence, a strategy of "leave it alone unless necessary" is recommended.

Background/Objectives: The distal transradial approach (dTRA) is increasingly used in interventional cardiology. Doppler Ultrasound (DUS) effectively assesses radial artery (RA) characteristics. This study aims to identify specific RA DUS characteristics in patients undergoing coronary procedures via dTRA. Methods: Participants from the ANTARES trial who completed the intervention per-protocol and retained RA patency were included. DUS was performed at baseline, 1 day, and 60 days post-procedure. Results: Among 400 participants, 348 had either dTRA (n = 169) or conventional transradial access (cTRA) (n = 179). Distal RA lumen diameter was 12% smaller than that of the proximal RA (p < 0.001). Men had a 14% larger distal RA diameter than women (2.33 ± 0.31 mm vs. 2.04 ± 0.27 mm, p < 0.0001), similar to the proximal RA relationship. Peak flow velocities were similar between the sexes. Univariate linear regression showed that height, weight, body mass index, and body surface area (BSA) predicted arterial size, with BSA remaining significant in multivariate analysis (beta coefficient 0.62; confidence interval 0.49-0.75; p < 0.0001). Distal RA diameter correlated positively with palpable pulse at the snuffbox and wrist. The dTRA resulted in an immediate 14% and 11% increase in distal and proximal RA diameter, respectively (both p < 0.05). Sixty days after dTRA, the distal RA remained slightly dilated (p < 0.05), while the proximal RA returned to baseline. Conclusions: Distal RA diameter is significantly associated with sex, measuring smaller than the forearm segment. A strong palpable pulse correlates with larger distal RA size. The dTRA induces RA lumen expansion. A thorough understanding of distal RA anatomy is essential for optimizing patient selection and refining techniques for transradial procedures.

Coronary catheterization by a distal radial approach at the site of the anatomical snuffbox has recently been reported to be both safe and useful. No data are available on the diameter of the distal radial artery (DRA) in Japan, and it is unclear whether the DRA is large enough to withstand the insertion of a conventional sheath by a traditional radial approach. We enrolled 142 patients who underwent coronary catheterization and evaluated the vessel diameter of the DRA using ultrasound. The vessel diameter of the DRA in the anatomical snuffbox (2.6 ± 0.5mm) was significantly smaller than that of the proximal radial artery (PRA) at the conventional puncture site (3.1 ± 0.4mm). The difference in vessel diameter between the DRA and PRA was 0.5 ± 0.4mm, and the DRA/PRA ratio was 0.8 ± 0.1. Although the vessel diameter of the DRA was positively correlated with that of the PRA (r = 0.66, p < 0.0001), in some cases the DRA was extremely small compared to the PRA. When the vessel diameter of the DRA is smaller than the outer diameter of the sheath scheduled for use, we should puncture the PRA at the outset. We could perform coronary catheterization by a distal radial approach without major bleeding or adverse events, and there was no radial artery occlusion at the site of the anatomical snuffbox or the forearm. For coronary catheterization by a distal radial approach, we should evaluate whether there is sufficient vessel diameter using ultrasound before the procedure. In addition, this approach can be an effective option from the viewpoint of radial artery preservation.

Morpho-Functional Features of the Radial Artery: Implications for Use as a Coronary Bypass Conduit

Ultrasonographic and functional evaluation of forearm circulation with occluded radial artery

Transradial approach is the classical access for coronary angiography and percutaneous coronary intervention (PCI). With the increase in the number of interventional procedures, some disadvantages of the transradial approach have also been found, it is easy to lead to various complications, such as radial artery occlusion, radial nerve injury, and puncture difficulties after radial artery spasm. Therefore, some experts put forward the approach of distal radial artery approach for interventional therapy, which has the advantages of convenient positioning, easy postoperative hemostasis, less damage to the proximal radial artery and improving patients' comfort. However, there is no special distal radial artery hemostat in clinic, which limits the development of this approach to a certain extent. Therefore, based on the principles of anatomy and physics, cardiovascular physician at Jiading District District Central Hospital in Shanghai designed and invented a distal radial artery hemostatic device, which is convenient for clinical hemostasis of distal radial artery puncture, and obtained the National Utility Model Patent (patent number: ZL 2021 2 2097829.6). The hemostatic device consists of a glove body with a silicone gasket protruding towards the skin on the inner surface and a binding component. The patient's hand is inserted into the glove body, and after being fixed by the restraint component, the silicone gasket can effectively compress the location of the radial artery puncture point, and play a good hemostatic effect with less pressure, avoid the common complications of proximal radial artery hemostatic, and reduce the discomfort of the patient. Has good application value.

The aim of this study was to evaluate the patency of the proximal and distal radial artery after coronary procedures performed via the distal radial artery (DRA). Ultrasound (US) as the most reliable method was used to diagnose radial artery occlusions (RAO). We evaluated 115 patients who underwent catheterization via distal radial access (dTRA). Following the procedure and after successful hemostasis (80 ± 36min), arterial patency and diameter at conventional transradial access (cTRA) and distal puncture sites (either in the anatomical snuffbox or the dorsal distal RA) were assessed. No RAO were found in the proximal or distal RA and there were no significant other complications. The mean diameter of the radial artery at conventional puncture site was 2.86 ± 0.49mm and at distal puncture site 2.31 ± 0.47mm (p < 0.001). Postprocedural compression time of dTRA was very short. In conclusion distal radial access was associated with the absence of early arterial occlusion, significant local bleeding and other relevant complications.

Histopathology and Morphometry of Radial Artery Conduits: Basic Study and Clinical Application