Feasibility of Coronary Angiography and Percutaneous Coronary Intervention via Left Snuffbox Approach

Distal Radial Access and Women: Implications for Access Site Outcomes in Coronary Procedures

BACKGROUND

We investigated the sex-specific variations in distal radial access (DRA)-associated outcomes, as well as the factors influencing these outcomes, by utilizing a comprehensive real-world registry.

METHODS

In this post-hoc analysis of the KODRA (Korean Prospective Registry for Evaluating the Safety and Efficacy of Distal Radial Approach) trial, we selected 4608 patients who underwent successful coronary procedures, including percutaneous coronary intervention or coronary angiography, via DRA. Primary end points were overall DRA site outcomes including bleeding, radial artery occlusion, tenderness, hand edema, numbness, perforation, and dissection. We performed both propensity score matching and multivariable logistic regression to evaluate sex-specific differences in DRA-associated outcomes. Moreover, a multivariable analysis using logistic regression was also performed to evaluate the independent associated factors of DRA site outcomes.

RESULTS

The mean age was 66.5±11.8 years, and 67.8% (3125 men and 1483 women) were male among 4608 enrolled patients. The incidence of overall DRA site outcomes was significantly higher in women than in men (7.5% versus 4.1%, P<0.001). However, there was no major bleeding in both groups. In the multivariable analysis, female sex was a significant risk factor of overall DRA site outcomes, along with body mass index, chronic kidney disease, percutaneous coronary intervention procedure, use of potent P2Y12 inhibitor, and unfractionated heparin dose.

CONCLUSIONS

This subgroup analysis of the KODRA trial by sex showed that overall DRA site outcomes following coronary procedures via DRA were more common in women than in men. However, no major bleeding was observed in either men or women.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT04080700.

Feasibility of Distal Radial Access in High Bleeding Risk Patients Who Underwent Percutaneous Coronary Intervention

BACKGROUNDS AND OBJECTIVES

The distal radial access (DRA), a potential alternative to the trans-radial approach (TRA), may offer advantages in terms of access site complications due to its smaller vessel diameter, especially for high bleeding risk (HBR) patients. This study aims to investigate the feasibility of DRA in HBR patients.

METHODS

Based on data from the KODRA registry, a prospective, multicenter cohort, this study analyzed 1,586 patients who underwent successful percutaneous coronary intervention (PCI) via DRA. Patients were categorized into HBR and non-HBR groups. The primary endpoint of the study is DRA-related bleeding, and the secondary endpoints of the study are overall access site complications and each component of the access site complications. To reduce the effect of potential confounders, a multivariable adjustment analysis was performed.

RESULTS

The mean age of the total population was 71.1±10.8 years, and 40.3% of patients were female. Both DRA-related bleeding (odds ratio [OR], 1.15; 95% confidence interval [CI], 0.67-1.97; p=0.616) and overall access site complications (OR, 1.08; 95% CI, 0.67-1.72; p=0.761) were not significantly different between the HBR group and non-HBR group after multivariable adjustment. No major bleeding before discharge was observed in both groups. Furthermore, the incidence of distal and conventional radial artery occlusion was less than 1% at 1-month follow-up in both groups.

CONCLUSIONS

Our study results showed the safety of DRA for both DRA-related bleeding and access site complications among HBR patients who underwent PCI.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04080700.

Efficacy and success rate of Distal Radial Artery Access at the Anatomical Snuffbox for Coronary Intervention at Central Chest Institute of Thailand

BACKGROUND

Distal radial artery access, which involves puncturing the radial artery at the anatomical snuffbox, is increasingly being adopted in interventional cardiology. This approach offers several advantages over traditional standard transradial access, including improved procedure positioning, a lower incidence of radial artery occlusion, and shorter hemostasis.

OBJECTIVE

To study the benefit of distal radial access during coronary angiography (CAG) or percutaneous coronary intervention (PCI) with palpation technique in terms of success rate, first attempt success, number of attempts, time to access, and complications.

METHOD

A prospective cohort study was performed between June 2022 and June 2023. Two hundred thirty-three patients received coronary intervention by three experienced transradial operators through right or left distal radial access.

RESULT

The mean age of patients was 62.9 years old. 58% of patients were male. Most patients had chronic coronary syndrome (35.6%), valvular heart disease (30.9%), and acute coronary syndrome (24.9%). The most used site was the right distal radial artery, and 6 Fr sheaths were mainly used. The median diameter of the distal radial artery measured by ultrasound was 0.26 (0.23-0.28) cm. First attempt success rate was 171 (73.4%). The median number of attempts was one (1.0-2.0). The median time to access the distal radial access was 1.15 (0.57-1.64) min. Puncture times were stabilized and improved after a higher number of procedures. Access site crossover was 25 (10.7%), mainly performed via the right radial artery 18 (7.7%). However, ultrasound guidance for bailout situations during puncture was done in 10 (4.3%), which achieved successful cannulation. The success rate of distal radial cannulation by palpation technique was 201(86.3%), and the overall success rate after the ultrasound-guided bailout situation was 211 (90.6%). There were 34 (14.6%) minor hematomas after the procedures, and one patient had thumb numbness.

CONCLUSION

Distal radial access at the anatomical snuffbox is an effective and viable alternative for coronary interventions in patients with a favorable radial pulse, demonstrating a high success rate. Ultrasound-guided puncture is an important bailout strategy when blind palpation appears difficult, significantly improving procedure success and reducing complications.

Can Distal Radial Access Replace Conventional Radial Access for Coronary Catheterization? A Study Comparing Puncture Time, Attempts, Patient and Operator Comfort

BACKGROUND

To compare distal (dTRA) and classical (cTRA) transradial approaches for coronary catheterization with respect to puncture attempts, puncture time, operator and patient comfort, and safety outcomes.

METHODS

In this prospective observational study, patients undergoing coronary catheterization for standard indications via dTRA or cTRA approaches from July 2019 to May 2020 were included. Clinicodemographic and laboratory characteristics were recorded. Puncture time, number of puncture attempts, operator and patient comfort on the visual analogue scale (VAS), and access site complications like hematoma and radial artery occlusion were recorded. Patients were analyzed in the same group as the initial puncture, even if there was a cross-over.

RESULTS

Of the 130 patients (40.8% women), 50.8% and 49.2% belonged to dTRA and cTRA groups, respectively. dTRA group required more than one puncture attempt more frequently than cTRA group (30.3% vs. 15.6%; P =.047); consequently, puncture time was longer (60s vs. 50s; P =.031, respectively). However, puncture time was comparable if the puncture was successful in the first attempt (47.5s vs. 45s; P =.492). Patient comfort was comparable (7.2 ± 0.9 vs. 7.2 ± 1.2; P =.852), but operator comfort was more with cTRA approach (8.3 ± 1.6 vs. 8.8 ± 1.2; P =.048). Post-procedure, cTRA had more minor bleeding than dTRA approach. There was no major bleeding in either group. The occurrence of radial artery occlusion was comparable in both groups.

CONCLUSION

Although dTRA needed more attempts for successful puncture, puncture time was comparable with cTRA when puncture was successful on the first attempt. Therefore, one attempt at dTRA puncture could be a reasonable approach in patients undergoing coronary catheterization.

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.

A narrative review of history, advantages, future developments of the distal radial access

This article presents a historical excursus and a review of modern literature on distal radial access for interventional surgery, discussing the anatomical and physiological substantiation of the use of this access point in endovascular surgery, its advantages and disadvantages. The main considerations directly related to distal puncture, choice of instrumentation, hemostasis, possible complications, and prevention are analyzed. The major areas of interventional surgery (coronary, vascular, oncological, and neurointerventional), where the distal radial approach is actively used, are reflected and their characteristics are highlighted. In general, it has been shown that with the development of technology, improved manual skills, the widespread use of hydrophilic introducers, and modern sheathless guiding catheters, the vessel diameter, and puncture site are not decisive factors when choosing access for any type of intervention.

Distal Versus Proximal Radial Arterial Access for Percutaneous Coronary Angiography and Intervention: Updated Meta-Analysis of Randomized Controlled Trials

Radial artery occlusion (RAO) is a major impediment to reintervention in patients who underwent proximal transradial access (p-TRA) for coronary catheterization. Distal transradial access (d-TRA) at the level of snuffbox distal to the radial artery bifurcation is a novel alternative to p-TRA. We conducted an updated meta-analysis of all available randomized controlled trials (RCTs) to compare the incidence of RAO between p-TRA and d-TRA, along with access site-related complications. PubMed, Web of Science, and Google Scholar were searched for RCTs published since 2017 to October 2023 comparing d-TRA and p-TRA for coronary angiography and/or intervention. Risk ratios (RRs) and mean differences (MDs) with 95% confidence intervals were calculated using the random-effects model for procedural and clinical outcomes for the 2 approaches. A total of 18 RCTs with 8,205 patients (d-TRA n = 4,096, p-TRA n = 4,109) were included. The risk of RAO (RR 0.31, 0.21 to 0.46, p ≤0.001) and time to hemostasis (minutes) (MD -51.18, -70.62 to -31.73, p <0.001) was significantly lower in the d-TRA group. Crossover rates (RR 2.39, 1.71 to 3.32, p <0.001), access time (minutes) (MD 0.93, 0.50 to 1.37, p <0.001), procedural pain (MD 0.46, 0.13 to 0.79, p = 0.006), and multiple puncture attempts (RR 2.13, 1.10 to 4.11, p = 0.03) were significantly higher in the d-TRA group. The use of d-TRA for coronary angiography and/or intervention is associated with a lower risk of RAO at the forearm and may preserve p-TRA site for reintervention in selective patients by reducing the incidence of RAO.

Efficacy and safety of sheathless guiding catheter for distal radial approach

OBJECTIVES

This study aimed to assess the efficacy and safety of a sheathless guiding system in patients who underwent percutaneous coronary intervention (PCI) with distal radial access (DRA).

BACKGROUND

Hyperion™ Sheathless® guiding catheter (Asahi Intecc, Japan), one of the latest 6-Fr guiding systems for transradial PCI characterized by novel outer dilator, is considered to facilitate smooth insertion of the catheter to the artery and may contribute to further reduction of access site complications in DRA.

METHODS

Between October 2018 and January 2023, 286 patients underwent PCI with a Hyperion™ Sheathless® guiding catheter with DRA at two Japanese hospitals. Procedural success, bleeding complications, and radial artery occlusion (RAO) detected by Doppler ultrasonography were assessed.

RESULTS

Mean age of the patients was 72.7 years, and 236 patients (82.5 %) were male. The target lesions were located in the right coronary artery, left anterior descending artery, left circumflex artery, and left main trunk in 81, 44, 50 patients, and 18 patients respectively. Procedural success rate was 99.7 % with no patients requiring conversion to conventional radial access. Two patients presented with a forearm hematoma equivalent to an Early Discharge After Transradial Stenting of Coronary Arteries Study hematoma classification Grade II and 23 with Grade I. No patient presented minor or major bleeding according to the Thrombolysis in Myocardial Infarction bleeding classification. RAO at 30-day follow-up was observed in 6 out of 277 patients (2.2 %).

CONCLUSIONS

6-Fr sheathless guiding system for PCI via DRA is feasible and associated with a low incidence of access site complications.

The distal radial artery: Versatile vascular access for transcatheter interventions

Conventional transradial access has been established as the gold standard for invasive coronary angiography and percutaneous interventions by the current European and American guidelines. The distal or snuffbox radial artery access represents an alternative transradial access site that allows radial sheath insertion with the patient's hand pronated. Firstly described 40 years ago, it exploded in popularity only recently. Promising additional benefits, the distal radial access is increasingly being adopted in various types of percutaneous interventions, being preferred by many interventional cardiologists and radiologists for its reduced vascular complications and time to hemostasis, and improvement of patient and operator comfort. Other centers consider it a fad, waiting for solid clear evidence and benefits. The evidence is dynamic and discrepant, depending on the center, the operator, and how it was collected (randomized controlled vs observational studies). Another essential aspect raised by "skeptics" was whether distal radial access, by its smaller diameter and more angled course, can support all types of interventions. The aim of this review is to gather all the scenarios where distal radial access has been utilized and to conclude whether this vascular access is feasible across all transcatheter interventions.

Distal Radial Access for Coronary Procedures in a Large Prospective Multicenter Registry: The KODRA Trial

BACKGROUND

Distal radial access (DRA) as an alternative access route lacks evidence, despite its recent reputation.

OBJECTIVES

The aim of this study was to evaluate the safety and feasibility of DRA on the basis of daily practice.

METHODS

The KODRA (Korean Prospective Registry for Evaluating the Safety and Efficacy of Distal Radial Approach) trial was a prospective multicenter registry conducted at 14 hospitals between September 2019 and September 2021. The primary endpoints were the success rates of coronary angiography (CAG) and percutaneous coronary intervention (PCI). The secondary endpoints included successful distal radial artery puncture, access-site crossover, access site-related complications, bleeding events, and predictors of puncture failure.

RESULTS

A total of 4,977 among 5,712 screened patients were recruited after the exclusion of 735 patients. The primary endpoints, the success rates of CAG and PCI via DRA, were 100% and 98.8%, respectively, among successful punctures of the distal radial artery (94.4%). Access-site crossover occurred in 333 patients (6.7%). The rates of distal radial artery occlusion and radial artery occlusion by palpation were 0.8% (36 of 4,340) and 0.8% (33 of 4,340) at 1-month follow-up. DRA-related bleeding events were observed in 3.3% of patients, without serious hematoma. Multilevel logistic regression analysis identified weak pulse (OR: 9.994; 95% CI: 7.252-13.774) and DRA experience <100 cases (OR: 2.187; 95% CI: 1.383-3.456) as predictors of puncture failure.

CONCLUSIONS

In this large-scale prospective multicenter registry, DRA demonstrated high success rates of CAG and PCI, with a high rate of puncture success but low rates of distal radial artery occlusion, radial artery occlusion, bleeding events, and procedure-related complications. Weak pulse and DRA experience <100 cases were predictors of puncture failure. (Korean Prospective Registry for Evaluating the Safety and Efficacy of Distal Radial Approach [KODRA]; NCT04080700).

Effectiveness and Safety of Left Distal Transradial Access in Coronary Procedures in the Caribbean

INTRODUCTION

This retrospective study investigated the effectiveness and safety of left distal transradial access (LDTRA) in patients with cardiovascular disease in Trinidad undergoing coronary angiography (CAG) or percutaneous coronary intervention (PCI).

METHOD

Procedural parameters, including technical success and safety outcomes such as vascular complications and radial artery occlusion (RAO), were assessed in 111 consecutive patients undergoing CAG or PCI from January 2023 to June 2023 at the Eric Williams Medical Sciences Complex, Trinidad and Tobago. Eighty-eight patients underwent LDTRA, while 23 received left transradial access (LTRA).

RESULTS

There was no difference in procedural success with LDTRA compared to LTRA, 90.9% vs. 100%, p-value 0.202, non-significant (ns). LDTRA was associated with shorter fluoroscopy times (8.4 ± 6.8 minutes vs. 12.4 ± 7.7 minutes, p-value = 0.02), procedural duration (26.7 ± 18 minutes vs. 35.8 ± 20 minutes, p-value = 0.04), and hemostasis time (142 ± 41 minutes vs. 186 ± 44 minutes, p-value < 0.05). There were no significant differences in procedural-related complications (8% for LDTRA vs. 4.3% for LTRA, p-value = 0.476, ns). There were no reported cases of RAO. In the subgroup of patients with prior coronary artery bypass grafting (CABG), the fluoroscopy and procedure times were similar for both access sites; however, LDTRA was associated with a shorter hemostasis time (128 ± 30 minutes vs. 194 ± 39 minutes, p-value = 0.01).

CONCLUSIONS

LDTRA is effective and safe for coronary procedures and is associated with a shorter hemostasis time. This study may prove clinically pertinent in a limited-resource Caribbean setting.

Randomized comparison of Glidesheath Slender with conventional 5Fr arterial sheaths for coronary angiography through the distal radial artery

BACKGROUND

The potential benefits of the thin-walled 5F Glidesheath Slender sheath in the distal transradial access (dTRA) have not been investigated. This study aimed to compare the Glidesheath Slender versus conventional 5Fr arterial sheaths in patients undergoing diagnostic coronary angiography (CAG) through the dTRA.

METHODS

A total of 352 consecutive patients with an indication for CAG were randomized (1:1) to Glidesheath Slender 5Fr versus a conventional 5Fr arterial sheath for dTRA. The primary endpoint was the rate of successful hemostasis at 30 minutes after sheath removal. Follow-up ultrasound of the right radial and distal radial artery was performed 7-10 days after the procedure.

RESULTS

After exclusion of patients where a 6Fr sheath or crossover of access site was required, 108 patients in the Glidesheath Slender and 105 patients in the conventional 5Fr arterial sheath group were included in the analysis. The crossover rate to conventional radial access and the rate of successful hemostasis at 30 minutes after sheath removal were similar between the two groups (18.9% in the Glidesheath slender vs. 22% in the control group; P=0.460, and 62% vs. 51.4%; P=0.118, respectively). The level of pain associated with the procedure was significantly lower in the Glidesheath Slender group (2.69 vs. 3.29 in the control group; P=0.02). No significant difference was recorded between the two groups in the rate of access-related complications.

CONCLUSIONS

Use of Glidesheath Slender for dTRA did not increase the rate of early hemostasis compared with conventional arterial sheath.

Predictors of success and puncture site complications in the distal radial approach

The distal radial approach (DRA) has been proposed as an alternative approach for coronary angiography (CAG) and percutaneous coronary intervention (PCI); however, the predictors of DRA failure and puncture site complications are unclear. Among 7153 consecutive patients undergoing CAG or PCI between November 2018 and January 2021, 3610 patients undergoing CAG or PCI with DRA were analyzed. The primary endpoint of this study was the procedural success, and the secondary endpoint of this study was puncture site complications during procedure. Puncture site complications during procedure were defined as a composite of major bleeding, minor bleeding, arteriovenous fistula, pseudoaneurysm, and neuropathy. The DRA success rate and the puncture site complication rate were 90.4% and 7.7%, respectively. The predictors of DRA failure were low body weight and dual antiplatelet therapy; those of DRA success were PCI and ultrasonography-guided DRA; those of puncture site complications during procedure were low body weight, peripheral arterial disease, dual antiplatelet therapy, anticoagulant therapy, and PCI; and that of no puncture site complications were previous PCI and ultrasonography-guided DRA. The negative predictors of DRA success with no puncture site complication during procedure were low body weight and dual antiplatelet therapy. The positive predictor of DRA success with no puncture site complication during procedure was ultrasonography-guided DRA. We identified the predictors of DRA failure and puncture site complications during procedure in patients undergoing CAG and PCI with DRA. Ultrasonography-guided DRA was associated with a high DRA success rate and a low puncture site complication rate in patients undergoing CAG or PCI with DRA.

Feasibility of distal transradial access for coronary angiography and percutaneous coronary intervention: an observational and prospective study in a Latin-American Centre

BACKGROUND

Distal transradial access (dTRA) as a refinement of the conventional transradial access (TRA) has advantages in terms of risk of radial artery occlusion (RAO). In order to evaluate the real-world feasibility and safety of dTRA as the default access site for routine coronary angiography (CAG) and percutaneous coronary intervention (PCI) in a Latin-American centre, this prospective observational registry was conducted.

METHODS

Consecutive patients with a prior assessment for CAG and/or PCI were enrolled in this single-centre prospective registry from October 2018 to March 2019. The primary endpoints were the success rate of CAG and PCI. Secondary endpoints included the success rate of puncture of the distal radial artery, complications at the puncture site and puncture time.

RESULTS

The success rates of CAG and PCI were 100% (155/155) and 97% (69/71), respectively. Puncture time and fluoroscopic time were 52 ± 19 seconds and 16.3 ± 35.4 minutes, respectively. Haemostasis time was 142 ± 45 min. A total of 19 (12.5%) puncture site complications occurred, including 18 (11.6%) minor haematomas and one (0.6%) arterial perforation, in which the artery was patent at the one-month follow-up. Five patients complained of left thumb numbness at a one-month follow-up. No distal radial artery occlusion, pseudoaneurysm, or arteriovenous fistula occurred.

CONCLUSIONS

The success and complication rates of ldTRA support the feasibility and safety of this procedure using the appropriate materials in previously selected patients.

A randomized trial comparing left distal radial versus femoral approach for coronary artery bypass graft angiography: a pilot study

BACKGROUND

Left distal transradial angiography (ldTRA) is a new technique for radial coronary angiography and may be an alternative to conventional transfemoral angiography (TFA) in patients who had previously undergone coronary artery bypass graft (CABG) surgery. In this study we compared ldTRA with TFA in patients who had undergone CABG surgery in terms of procedural details.

METHODS

Fifty-seven consecutive patients with history of previous CABG among 459 patients who were admitted to coronary angiography unit (elective and acute coronary syndromes) in our center between October 2019 and February 2020 were included in the study. Consecutive patients were randomized to ldTRA (34 patients) and TFA (23 patients) group. The difference in total procedure times was defined as primary endpoint. The difference in sheat times, fluoroscopy times, contrast volume used and radiation exposure were designated as secondary endpoints. Post angiographic complications were compared between two groups.

RESULTS

Out of 34 patients, successful distal radial access was obtained in 25 patients (74%). Baseline demographics, contrast use and radiation exposure were similar between groups. Sheath times in ldTRA was significantly longer (P<0.001), but total procedure times were not different (18.4±7.8 vs. 14.6±6.1, P=0.07). Non-standard angiographic equipment usage was significantly higher in ldTRA procedures (80% vs. 13%, P<0.001). There was no major bleeding in neither of groups, and three minor bleedings in FA group (0% vs.13%, P=0.10).

CONCLUSIONS

ldTRA in patients with a palpable pulse and successful access might be used successfully for angiography in patient with previous CABG even early in an operator's experience.

Comparison of spasmolytic regimen for prevention of radial artery spasm during the distal radial approach: A single-center, randomized study

Background

The distal radial approach (DRA) for coronary catheterization is increasingly being used worldwide yet the optimal medication regimen to prevent radial artery spasm (RAS), an important factor for the success of the procedure, remains unclear. The aim of this study is to examine the effectiveness of medication for preventing RAS via the DRA.

Methods

This was a prospective, comparative randomized study including 400 patients who underwent coronary catheterization via DRA in single center by three experienced DRA operators. Patients were randomized to either nitroglycerin (NTG) injection (N = 200) or NTG plus verapamil (N = 200) to compare the effectiveness and safety of these regimens.

Results

There were no differences between the groups in the changes in radial artery diameter at most spastic area (0.34 ± 0.20 in the NTG group, 0.35 ± 0.20 in the NTG plus verapamil group; P = 0.73). There was no difference between the groups in the ratio of patients without arm pain during the procedure (95.0% in the NTG group, 93.5% in the NTG plus verapamil group; P = 0.67). However, there was a greater reduction in diastolic blood pressure in the NTG plus verapamil group (-8.3 ± 7.9 mmHg) than in the NTG group (-6.6 ± 7.6 mmHg) (P = 0.03).

Conclusion

Intra-arterial injection of NTG as a single agent is effective and safe in the prevention of RAS during coronary catheterization via the DRA compared with a cocktail regimen of NTG plus verapamil.

Clinical trial registration

https://cris.nih.go.kr, identifier KCT0005177.

Application of ultrasound in cardiovascular intervention via the distal radial artery approach: New wine in old bottles?

The distal radial artery (DRA) approach has emerged as a new approach in cardiovascular intervention. In recent years, ultrasound has been widely used in cardiovascular intervention via the DRA approach. This article systematically discusses the progress of ultrasound in the preoperative vascular assessment, intraoperative guided puncture and postoperative observation of complications via the DRA approach.

The technical features of the diagnosis or treatment of coronary artery disease through the distal radial artery approach at the anatomical snuffbox compared with the conventional radial artery approach

Background

To compare the surgical effects of coronary intervention through the transradial intervention (TRI) versus distal transradial intervention (dTRI) approach.

Methods

From September 2020 to April 2021, 302 patients undergoing coronary artery angiography (CAG) or percutaneous coronary intervention in our hospital were retrospectively included. Patients were divided into the TRI group and dTRI group with 151 cases in each group. The technique features, lesion features, and cannulation process were compared between the two groups.

Results

The number of patients who underwent CAG in the dTRI group (35.1%) was significantly greater compared with the TRI group (12.6%) (P < 0.01). The rates of triple vessel lesions, calcification lesions and chronic total occlusion lesions were increased in the TRI group compared with the dTRI group (P < 0.05). The average radial artery diameter (RAD) in the TRI group (2.550 ± 0.417 mm) was greater than that in the dTRI group (2.070 ± 0.360 mm) (P < 0.05). The hemostasis time of the dTRI group (173.272 ± 41.807 min) was lower than that of the TRI group (273.417 ± 42.098 min) (P < 0.05). The radial artery occlusion (RAO) rates in the dTRI group (2.6%) were lower than those in the TRI group (8.6%) (P < 0.05). The dTRI group had a higher satisfaction score than the TRI group (P > 0.05). RAD at the puncture site was a predictor of the overall cannulation success rate with an AUC of 0.747 (95% CI 0.663–0.860; P < 0.05).

Conclusions

Despite a steep learning curve, the dTRI approach had a shorter hemostasis time, reduced RAO rates, and notable preliminary safety results compared with the TRI approach. The dTRI approach can be used as a supplemental method to the TRI approach.

Distal versus conventional radial access for coronary angiography and intervention: Design and rationale of DISCO RADIAL study

BACKGROUND

Transradial access (TRA) has become the default access method for coronary diagnostic and interventional procedures. As compared to transfemoral access, TRA has been shown to be safer, cost-effective and more patient-friendly. Radial artery occlusion (RAO) represents the most frequent complication of TRA, and precludes future coronary procedures through the radial artery, the use of the radial artery as a conduit for coronary artery bypass grafting or as arteriovenous fistula for patients on hemodialysis. Recently, distal radial access (DRA) has emerged as a promising alternative to TRA, yielding potential for minimizing the risk of RAO. However, an international multicenter randomized comparison between DRA, and conventional TRA with respect to the rate of RAO is still lacking.

TRIAL DESIGN

DISCO RADIAL is a prospective, multicenter, open-label, randomized, controlled, superiority trial. A total of 1300 eligible patients will be randomly allocated to undergo coronary angiography and/or percutaneous coronary intervention (PCI) through DRA or TRA using the 6 Fr Glidesheath Slender sheath introducer. Extended experience with both TRA and DRA is required for operators' eligibility and optimal evidence-based best practice to reduce RAO systematically implemented by protocol. The primary endpoint is the incidence of forearm RAO assessed by vascular ultrasound at discharge. Several important secondary endpoints will also be assessed, including access-site cross-over, hemostasis time, and access-site related complications.

SUMMARY

The DISCO RADIAL trial will provide the first large-scale multicenter randomized evidence comparing DRA to TRA in patients scheduled for coronary angiography or PCI with respect to the incidence of RAO at discharge.

Intelligent Algorithm-Based Multislice Spiral Computed Tomography to Diagnose Coronary Heart Disease

In this study, dictionary learning and expectation maximization reconstruction (DLEM) was combined to denoise 64-slice spiral CT images, and results of coronary angiography (CAG) were used as standard to evaluate its clinical value in diagnosing coronary artery diseases. 120 patients with coronary heart disease (CHD) confirmed by CAG examination were retrospectively selected as the research subjects. According to the random number table method, the patients were divided into two groups: the control group was diagnosed by conventional 64-slice spiral CT images, and the observation group was diagnosed by 64-slice spiral CT images based on the DLEM algorithm, with 60 cases in both groups. With CAG examination results as the standard, the diagnostic effects of the two CT examination methods were compared. The results showed that when the number of iterations of maximum likelihood expectation maximization (MLEM) algorithm reached 50, the root mean square error (RMSE) and peak signal to noise ratio (PSNR) values were similar to the results obtained by the DLEM algorithm under a number of iterations of 10 when the RMSE and PSNR values were 18.9121 dB and 74.9911 dB, respectively. In the observation group, 28.33% (17/60) images were of grade 4 or above before processing; after processing, it was 70% (42/60), significantly higher than the proportion of high image quality before processing. The overall diagnostic consistency, sensitivity, specificity, and accuracy (88.33%, 86.67%, 80%, and 85%) of the observation group were better than those in the control group (60.46%, 62.5%, 58.33%, and 61.66%). In conclusion, the DLEM algorithm has good denoising effect on 64-slice spiral CT images, which significantly improves the accuracy in the diagnosis of coronary artery stenosis and has good clinical diagnostic value and is worth promoting.

Reference diameter and characteristics of the distal radial artery based on ultrasonographic assessment

BACKGROUND/AIMS

While distal radial artery (DRA) access is increasingly being used for diagnostic coronary angiography, limited information is available regarding DRA size. We aimed to determine the DRA reference diameters of Korean patients and identify the predictors of DRA diameter < 2.3 mm.

METHODS

The outer bilateral DRA diameters were assessed using a linear ultrasound probe in 1,162 consecutive patients who underwent transthoracic echocardiography. The DRA diameter was measured by the perpendicular angle in the dorsum of the hand, and the average values were compared by sex. DRA diameter < 2.3 mm was defined as unsuitable for routine diagnostic coronary angiography using a 5 Fr introducer sheath.

RESULTS

The mean DRA diameters were 2.31 ± 0.43 mm (right) and 2.35 ± 0.45 mm (left). The DRA was smaller in women than men (right: 2.15 ± 0.38 mm vs. 2.43 ± 0.44 mm, p < 0.001; left: 2.18 ± 0.39 mm vs. 2.47 ± 0.45 mm, p < 0.001). The DRA diameter was approximately 20% smaller than the radial artery diameter. A total of 630 (54.2%) and 574 (49.4%) patients had DRA diameter < 2.3 mm in the right and left hands, respectively. Female sex, low body mass index (BMI), and low body surface area (BSA) were significant predictors of DRA diameter < 2.3 mm.

CONCLUSION

We provided reference DRA diameters for Korean patients. Approximately 50% of the studied patients had DRA diameter < 2.3 mm. Female sex, low BMI, and low BSA remained significant predictors of DRA diameter < 2.3 mm.

Distal or Traditional Transradial Access Site for Coronary Procedures: A Single-Center, Randomized Study

OBJECTIVES

This study aimed to compare the efficacy and safety of the distal transradial approach (dTRA) versus the conventional transradial approach (TRA) for coronary angiography and percutaneous coronary interventions.

BACKGROUND

The recommended approach for coronary procedures is TRA. However, it is associated with radial artery occlusion (RAO). The dTRA could potentially decrease the incidence of RAO.

METHODS

One thousand forty-two consecutive patients were randomized (1:1) to right dTRA or TRA. The primary endpoint was the rate of RAO, which was evaluated by Doppler ultrasound at 60 days after randomization.

RESULTS

Five hundred eighteen and 524 patients were randomized to dTRA and TRA, respectively. Follow-up Doppler evaluation of the radial artery was accomplished in 404 (78.0%) patients in the dTRA group and 392 (74.8%) in the TRA group. The rate of RAO was significantly reduced in the dTRA group compared with TRA group (3.7% vs 7.9%, respectively; P = 0.014). The rate of successful sheath insertion was lower in the dTRA group compared with the TRA group (78.7% vs 94.8%, respectively; P < 0.001). More punctures (median = 2 [IQR: 1-3] vs median = 1 [IQR: 1-2]; P < 0.001) and a longer time (120 vs 75 seconds; P < 0.001) were required for sheath insertion in the dTRA group compared with the TRA group. The hemostasis time was shorter in the dTRA group compared with the TRA group (60 vs 120 minutes; P < 0.001). The dose area product was higher in the dTRA group (median = 32,729 in the dTRA vs 28,909 cGy/cm² in the TRA group; P = 0.02). No significant differences were observed in the secondary safety endpoints (bleeding [Bleeding Academic Research Consortium ≥ 2] and severe radial artery spasm).

CONCLUSIONS

According to our study, dTRA was associated with a lower rate of forearm RAO, a shorter time of hemostasis, a higher crossover rate and dose area product, and a longer procedural time compared with TRA.

Distal radial secondary access for transcatheter aortic valve implantation: The minimalistic approach

BACKGROUND

Although not yet recommended by the guidelines, distal radial access, a new site for cardiovascular interventions, has been rapidly acknowledged and adopted by many centers due to its high rate of success, safety and fewer complications. We present our experience using secondary distal radial access during transcatheter aortic valve implantation (TAVI), proposing a new, even more minimal approach.

METHODS

As of November 2020, a systematic distal radial approach as secondary access site for TAVI was adopted in our center. Primary endpoints were technical success and major adverse events (MAEs). Secondary endpoints: the access site complication rate, hemodynamic and clinical results of the intervention, procedural related factors, crossover rate to the femoral access site, and hospitalization duration (in days).

RESULTS

From November 2020, 41 patients underwent TAVI using this strategy. Patients had a mean age of 76 ± 11.2 years, 41% were male. Six (14.63%) patients received a balloon-expandable valve and 35 (85.37%) received a self-expandable valve. TAVI was successful in all cases. No complications occurred due to transradial access. Puncture success, defined as completed sheath placement was maximum (N = 41/41,100%) and emergent transfemoral secondary access was not required in any case. Primary transfemoral vascular access site complications occurred in 7 cases (17%) of which 4 (13.63%) were resolved through distal radial access: one occlusion, two flow-limiting stenoses and four perforations of the common femoral artery. There were no additional major vascular complications at 30 days. Overall MACE rate was 2.4%.

CONCLUSION

The use of the distal radial approach for secondary access in TAVI is safe, feasible and has several advantages over old access sites.

Radial artery access anatomy: considerations for neuroendovascular procedures

Although enthusiasm for transradial access for neurointerventional procedures has grown, a unique set of considerations bear emphasis to preserve safety and minimize complications. In the first part of this review series, we will review important anatomical considerations for safe and easy neuroendovascular procedures from a transradial approach. These include normal and variant radial artery anatomy, the anatomic snuffbox, as well as axillary, brachial, and great vessel arterial anatomy that is imperative for the neuroendovascular surgeon to be intimately familiar prior to pursuing transradial access procedures. In the next part of the review series, we will focus on safety and complications specific to a transradial approach.

Distal radial artery approach for endovascular therapy

It has been reported that the distal transradial approach (dTRA) is safe and useful for percutaneous coronary intervention (PCI). In this study we evaluated the safety and efficacy of the dTRA for endovascular therapy (EVT). The dTRA for EVT was performed in 43 lesions from 35 patients. Approach site was determined at the discretion of the operator. Clinical data were analyzed retrospectively. Average patient age was 74.0 ± 6.5 years; 30 (86%) were male; average height was 161.1 ± 8.4 cm. Diabetes mellitus, hypertension, dyslipidemia, and smoking habit were present in 19 (54.3%), 31 (88.6%), 29 (82.9%), and 29 (82.9%) patients, respectively. Target lesions were iliac artery in 38 (88.4%) patients, superficial femoral artery in 4 (9.3%) and renal artery in the remaining patient (2.3%). Eight lesions (18.6%) were chronic total occlusions. Thirteen (30.2%), 2 (4.7%), and 28 (65.1%) lesions were treated using 4.5, 6, and 7 French long guiding systems, respectively. All lesions were successfully treated without any procedural or access site-related complications. No additional puncture sites were required. Ankle brachial index significantly improved from 0.62 ± 0.20 to 0.92 ± 0.17 (p < 0.0001) post-treatment for the lower limbs. There were no radial artery occlusions, target lesion revascularization, or complications 1 month later. Similar to PCI, the dTRA for EVT is safe and feasible without any specific complications in carefully selected patients.

Comparison of Distal Radial, Proximal Radial, and Femoral Access in Patients with ST-Elevation Myocardial Infarction

Recent studies have indicated that distal radial access (DRA) is feasible in patients undergoing percutaneous coronary intervention (PCI). The present study aimed to compare DRA, proximal radial access (PRA), and femoral access (FA) in patients with ST-elevation myocardial infarction (STEMI) undergoing PCI. Data were analyzed for 109 patients with STEMI treated via primary PCI from March 2020 to May 2021. The success rate of DRA was 83.3% (35/42), including seven cases of failed puncture (puncture failure = 5, severe radial artery spasm = 2). Primary PCI via the DRA was successful in all 35 patients. After classifying the patients requiring crossover into a separate group, the percentage of the puncture time in the door-to-wiring time was 2.7% [2.2–4.3], 3.3% [2.3–4.0], 2.6% [1.2–4.9], and 27.0% [13.5–29.3] in the DRA (n = 35), PRA (n = 24), FA (n = 26), and crossover (n = 9) groups, respectively (p < 0.01). Only two local hematomas (≤5 cm) occurred in the DRA group, while one patient in the FA group required surgical treatment and a transfusion for an access-site vascular injury. When performed by an experienced operator, DRA may represent a feasible alternative to other access routes in select patients with STEMI undergoing PCI, such as those with a high risk of bleeding.

Distal Transradial (Snuffbox) Access for Coronary Catheterization: A Systematic Review

Distal transradial access, through puncture of the radial artery at its course in the anatomical snuffbox, has emerged recently as an alternative approach for coronary catheterization. Several advantages of this approach seem promising and several studies are trying to elucidate its features. This review provides an overview of the snuffbox approach for coronary catheterization and summarizes the key results of the research conducted so far.

Optimal hemostasis duration for percutaneous coronary intervention via the snuffbox approach: A prospective, multi-center, observational study (HEMOBOX)

BACKGROUND

Percutaneous coronary intervention (PCI) via the distal radial access (DRA), called as snuffbox approach, recently has been increased worldwide due to fewer complications. Generally, since the diameter of distal radial artery is smaller than the radial artery, it is expected that the hemostasis duration can be shortened; however, there are no prospective studies. Furthermore, there is a lack of data about the feasibility of DRA for PCI.

METHODS

We prospectively collected data from 250 patients who were performed PCI via the DRA by three multi-center operators between March 2019 and December 2019. The primary outcome was hemostasis duration. Secondary outcomes were success rate of PCI, cannulation time, and puncture site complications.

RESULTS

Mean age of study population was 65.1 ± 10.3 years, success rate of PCI via the DRA was 99.2% (250/252) and 91.2% (228/250) patients was performed PCI via 6-French sheath. The cannulation time was 131 ± 98 s and the average hemostasis duration was 199 ± 50 min, and the median time was 180 [180-200] min. There are few minor hematomas (8.0%) and puncture site numbness (1.6%) with no radial artery occlusion.

CONCLUSIONS

HEMOBOX trial first reported hemostasis duration for PCI using the DRA, approximately 3 h, with 99.2% success rate and few minor complications.

TRIAL REGISTRATION

https://clinicaltrials.gov/ct2/show/NCT03863652.

The learning curve of the distal radial access for coronary intervention

Recently, coronary angiography (CAG) and percutaneous coronary intervention (PCI) via the distal radial access (DRA), are gaining attention owing to fewer complications. Despite the advantages of the DRA, there is difficulty to initiate this new vascular approach. The data from 1000 patients who underwent CAG and PCI via the DRA by a single experienced radial operator were retrospectively analyzed. The primary outcome was the success rate of the DRA per 100 cases. Moreover, the predictors of the failed DRA were analyzed. Overall, 952 (95.2%) of the total 1,000 patients underwent a successful DRA. After experiencing 200 cases, the DRA success rate was well maintained at > 94%, and there was no difference in success rate per 100 cases (P_trend = 0.216). The predictors of failure were female sex [odds ratio (OR) 1.84, 95% confidence interval (CI) 1.01–3.39, P = 0.049] and systolic blood pressure (SBP) of < 120 mmHg (OR 1.87, 95% CI 1.04–3.36, P = 0.036). For achieving a stable DRA with the success rate of > 94%, 200 procedures would be needed. Moreover, this new approach could fail in women and patients with low SBP.

Trial registration: https://cris.nih.go.kr/cris/index/index.do (Unique identifier: KCT0005349).

Efficacy and safety of distal radial approach for cardiac catheterization: A systematic review and meta-analysis

BACKGROUND

The traditional radial approach (RA) is recommended as the standard method for coronary angiography (CAG), while a distal RA (DRA) has been recently used for CAG.

AIM

To assess the efficacy and safety of the DRA vs RA during CAG.

METHODS

The following databases were searched through December 2020: MEDLINE, the Cochrane Central Register of Controlled Trials, EMBASE, the World Health Organization International Clinical Trials Platform Search Portal, and ClinicalTrials.gov. Individual randomized-controlled trials for adult patients undergoing cardiac catheterization were included. The primary outcomes were the successful cannulation rate and the incidence of radial artery spasm (RAS) and radial artery occlusion (RAO). Study selection, data abstraction and quality assessment were independently performed using the Grading of Recommendations, Assessment, Development, and Evaluation approach.

RESULTS

Three randomized control trials and 13 registered trials were identified. The two approaches showed similar successful cannulation rates [risk ratio (RR) 0.90, 95% confidence interval (CI): 0.72-1.13]. The DRA did not decrease RAS (RR 0.43, 95%CI: 0.08-2.49) and RAO (RR 0.48, 95%CI: 0.18-1.29). Patients with the DRA had a shorter hemostasis time in comparison to those with the RA (mean difference -6.64, 95%CI: -10.37 to -2.90). The evidence of certainty was low.

CONCLUSION

For CAG, the DRA would be safer than the RA with comparable cannulation rates. Given the limited data, additional research, including studies with standard protocols, is necessary.

Feasibility and Safety of the Left Distal Radial Approach in Percutaneous Coronary Intervention for Bifurcation Lesions

Recently, the left distal radial approach (DRA) for percutaneous coronary intervention (PCI) has been shown to be a feasible option, but there are limited data regarding the feasibility of performing bifurcation PCI via the left DRA. Therefore, this study aimed to describe our experience with the contemporary left DRA to perform PCI of bifurcation lesions. Between December 2017 and December 2019, we identified 106 patients treated with bifurcation PCI via the left DRA. We evaluated the success rate of PCI, access-site complications including major bleeding requiring surgery or transfusion, hematoma, distal and forearm radial artery occlusion, and 30-day mortality. Eleven patients (10.4%) treated with left main bifurcation and true bifurcations accounted for 39.6% of cases, with the left anterior descending artery/diagonal branch being the most frequent bifurcation site (57.5%, 61/106). PCI was performed using a 6-French guiding catheter in 101 (95.3%) cases. Successful PCI for bifurcation lesions via the left DRA was achieved in all 106 patients without access-site cross-over. There was no major bleeding, distal and forearm radial artery occlusion, forearm hematoma, or mortality at 30 days. The left DRA is a safe and feasible alternative access site for bifurcation PCI in selected patients.

Feasibility and Safety of Chronic Total Occlusion Percutaneous Coronary Intervention via Distal Transradial Access

Aims: The current study aims to verify the feasibility and safety of chronic total occlusion (CTO)-percutaneous coronary intervention (PCI) via the distal transradial access (dTRA). Methods: Between April 2017 and December 2019, 298 patients who underwent CTO PCI via dTRA were enrolled in this study. The baseline demographic and procedural characteristics were listed and compared between groups. The incidences of access-site vascular complications and procedural complications and mortality were recorded. Results: The mean J-CTO (Japanese chronic total occlusion) score was 2.6 ± 0.9 points. The mean access time was 4.6 ± 2.9 min, and the mean procedure time was 115.9 ± 55.6 min. Left radial snuffbox access was performed successfully in 286 patients (96.5%), and right radial snuffbox access was performed successfully in 133 patients (97.7%). Bilateral radial snuffbox access was performed in 107 patients (35.9%). 400 dTRA (95.5%) received glidesheath for CTO intervention. Two patients (0.7%) developed severe access-site vascular complications. None of the patients experienced severe radial artery spasm and only 2 patients (0.5%) developed radial artery occlusion during the follow-up period. The overall procedural success rate was 93.5%. The procedural success rate was 96.5% in patients with antegrade approach and 87.7% in patients with retrograde approach. Conclusions: It is both safe and feasible to use dTRA plus Glidesheath for complex CTO intervention. The incidences of procedure-related complications and severe access-site vascular complications, and distal radial artery occlusion were low.

Transradial Interventions at the Forefront of Innovation

Interventional cardiology has witnessed tremendous changes over the years from a mainly diagnostic approach in an elective population to therapeutic strategies in critically ill patients. Currently, we can treat a broad spectrum of coronary artery, peripheral artery, and structural heart diseases with less invasive, percutaneous approaches that we did not anticipate to be possible just a decade ago. It is certain that the interventional techniques will see further development and we will be able to treat by percutaneous methods more conditions previously thought beyond our reach. Regardless of the advances in catheter-based diagnostic and therapeutic techniques, one thing remains constant. They all require vascular access. And, vascular access is the first technical part of any percutaneous cardiovascular procedure that can determine its overall success. High-quality data together with the availability of training courses for interventional cardiologists and fellows-in-training ensure systematic use of the transradial approach (TRA) which has demonstrated a considerable benefit compared to transfemoral approach both in chronic and acute coronary syndromes. Constant improvement of TRA techniques will further facilitate transradial endovascular and structural interventions, and the growing use for high-risk and complex percutaneous coronary interventions. A continuously growing body of evidence is focused on surpassing current TRA limitations (specifically radial artery occlusion) and expanding alternative vascular accesses such as transulnar approach or distal TRA ("snuff-box" technique). Should this downsizing trend continue, we could see a further paradigm shift toward using the snuff-box technique.

Distal Transradial Access for Coronary Angiography and Interventions in Everyday Practice: Data From the TRIANGLE Registry (TwitteR Initiated registry for coronary ANgiography in Germany via distaL radial accEss)

Introduction

Transradial access (TRA) has become the primary route for coronary angiography (CAG) and percutaneous coronary interventions (PCI). Recently a new puncture site more distally in the area of the anatomical snuffbox has been described. With this multicenter registry, we wish to demonstrate the feasibility and safety of the distal radial access (dRA).

Methods

Between December 2018 and May 2019 all patients with a planned CAG or PCI via dRA in three cardiology centers in Germany were entered into this registry. Procedural data, puncture success, crossover rate and complications were registered. Proximal and distal radial artery patency were examined by ultrasound within 48 h.

Results

A total of 327 patients were enrolled (mean age: 69 ± 12 years, 69% male gender, 49% PCI), in 5 cases bilateral distal puncture was performed. Puncture success, defined as completed sheath placement was high (N = 316/332, 95%) and the crossover rate was low (27/332, 8%). The rate of proximal radial artery occlusion after 1–48 h was low (2/332 1%), the rate of occlusion at the distal puncture site was also very low (3/332, 1%). Major complications were not encountered.

Conclusion

Coronary angiography and interventions via the distal transradial access in the area of the anatomical snuffbox can be performed with a high rate of success and safety. This data suggests a reduced rate of radial artery occlusion compared to previously reported data after cannulation via the standard forearm radial artery puncture site. Randomized studies are needed to further investigate these results.

Trial Registration

This study was registered in the German registry for clinical trials: DRKS00017110, retrospectively on 07.May 2019

Distal Radial Access: Consensus Report of the First Korea-Europe Transradial Intervention Meeting

Among patients undergoing percutaneous coronary procedures, transradial access, compared with transfemoral access, is associated with a reduced risk for complications including mortality, especially in higher risk patients. However, transradial access is limited by radial artery occlusion (RAO) that despite being mostly asymptomatic because of the extensive anastomoses between the forearm arteries restricts future use of the same radial artery. Distal radial access (DRA) in the anatomic snuffbox or on the dorsum of the hand has recently gained global popularity as an alternative access route for vascular procedures. A strong anatomic and physiological rationale yields potential for significantly reduced risk for RAO and positive impact on procedural outcome for better patient care. Indeed, currently published studies buttress very low rates of RAO after DRA, hence supporting its development. The authors provide an analysis of the foundation of DRA, provide historical background, and offer a critical review of its current status and future directions. Also, given the limited evidence currently available to properly perform DRA in the real world, consensus opinion on what is considered optimal practice is also presented to supplement this document and enhance the implementation of DRA while minimizing its complications.

Safety of arterial catheterization using the distal radial approach in intensive care unit management: A pilot study

BACKGROUND

Arterial catheter (A-line) is essential for managing severely ill patients, and the radial artery is the most common insertion site in the intensive care unit (ICU). However, many accidental removals occur because the insertion site of A-line in the traditional radial approach (TRA) overlaps with the joint flexion. Recent reports have shown no significant difference in the complication rates between coronarography using the distal radial approach (DRA) and that using TRA. However, to date, no report has examined accidental removals of DRA in the ICU. This study aimed to retrospectively evaluate the safety of the DRA A-line in ICU management.

METHODS

This retrospective, descriptive, and observational study enrolled patients who underwent A-line insertion using the DRA at the authors' facility, which is a university hospital with approximately 1100 beds, from January 1, 2019 to August 31, 2019. The participants' clinical data were extracted from their medical records. The primary outcome was the number of accidental removals.

RESULTS

The study included 20 patients with a median age of 70 (interquartile range (IQR): 58.5-77) years: 10 patients with traumas, 6 with cerebral hemorrhages, 2 with gastrointestinal perforations, and 2 with other diagnoses. The number of punctures was 1 in 15 patients, 2 in 4 patients, and 3 in 1 patient. Only 1 patient required ultrasound guidance, whereas 12 patients required the use of guidewires. The median duration after insertion was 3 (IQR 2.5-5.5) days. Accidental removal was noted in only one patient. No other complications were observed during the period from insertion to removal.

CONCLUSIONS

DRA may be a safe option for insertion of a new A-line in the ICU.

Ultrasound-guided access to the distal radial artery at the anatomical snuffbox for catheter-based vascular interventions: a technical guide

Conventional radial access has been shown to have many advantages over the transfemoral approach. The risk of potential radial artery occlusion and subsequent hand ischaemia can be reduced further by accessing the vessel distally at the anatomical snuffbox, allowing maintenance of antegrade flow to the hand by the superficial palmar arch branch. Additional potential advantages of distal radial access in comparison to the conventional radial approach at the wrist include fewer puncture-site complications and faster post-procedural haemostasis as the vessel is very superficial. Furthermore, it provides another safe, non-femoral option for vascular access. The use of ultrasound guidance enables the operator to identify important anatomical landmarks and avoid injuring adjacent structures. We provide a detailed step-by-step guide for performing distal radial access using sonographic and anatomical correlation, thereby facilitating safe access and optimising technical success.

Manual versus mechanical compression hemostasis approach after coronary angiography via snuffbox access

OBJECTIVE

Distal radial artery access or trans-snuffbox access (TSA) is a novel, safe, and feasible technique for coronary artery interventions wherein its vascular hemostasis is still concerned. So, this study aimed to compare two homeostasis methods comprising manual and mechanical compression approaches in patients undergoing coronary angiography (CAG) via TSA.

METHODS

In a prospective nonrandomized clinical trial, a total of 80 patients undergoing diagnostic CAG by TSA were divided into two equal groups: manual compression and mechanical compression (using radial TR band), the main end point of which was primary hemostasis time. Other variables were patient satisfaction, puncture site pain severity, hospitalization time, and local neurovascular complication during the 30-day follow-up.

RESULTS

The mean age of the patients was 57.1±8.0 years, with 40 of them (54.1%) being male. The primary hemostasis time was significantly shorter in the manual compression approach [15.0±5.9 minutes with median 15 (9-20)] than in the TR band group [25.7±4.9 minutes with median 25 (20-30)] (p<0.001). No significant difference was noted in the patient's satisfaction and puncture site pain severity as well as hospitalization time between the two methods (p>0.050). The neurovascular complication, including hematoma, numbness, and dRA occlusion, rates had also no significant difference between the two groups (p>0.050).

CONCLUSION

The manual compression approach on the puncture site reduces hemostasis time in patients undergoing CAG via TSA when compared with the mechanical compression method.

Feasibility of primary percutaneous coronary intervention via the distal radial approach in patients with ST-elevation myocardial infarction

BACKGROUND/AIMS

Recently, distal radial approach (DRA), called as snuffbox approach, has gained the interest of interventional cardiologists, but there is a lack of data about the feasibility of DRA as an alternative route for primary percutaneous coronary intervention (PCI).

METHODS

A total of 138 patients presenting with ST-elevation myocardial infarction (STEMI) in whom primary PCI via the DRA was attempted at three hospitals from October 2017 to September 2019 were analyzed.

RESULTS

The success rate of snuffbox puncture in the setting of STEMI was 92.8% (128/138). Successful primary PCI via the DRA was achieved in all 128 patients. The snuffbox puncture time, defined as the time interval from local anesthesia induction to successful sheath cannulation, was 2.7 ± 1.6 minutes, and snuffbox puncture was performed within 5 minutes in 95.3% of patients. Moreover, the percentage of the puncture time in the door-to-balloon time was 3.3%. The left DRA was selected in 103 patients (80.5%), and primary PCI via the DRA was performed using a 6-Fr guiding catheter in 125 patients (97.7%). There was no major bleeding; however, there were four cases (3.1%) of access-site complications, including three cases of local hematoma (≤ 5 cm diameter) and one case of local numbness, which improved 3 months later.

CONCLUSION

In the setting of STEMI, the DRA could be a feasible alternative access route for primary PCI.

Applicability of left distal radial artery access site in ST-segment elevation myocardial infarction; A comparative evaluation with the conventional transfemoral approach

BACKGROUND

Left distal radial artery (LDRA) has got high popularity as an alternative safe access site in coronary angiography. However, little is known about its applicability in primary percutaneous coronary intervention (PPCI) in ST-segment elevation myocardial infarction (STEMI) patients. We aimed to assess the convenience of LDRA access in STEMI patients and make the comparative evaluation with the transfemoral (TF) route.

MATERIALS AND METHODS

A total of 91 consecutive STEMI patients who underwent PPCI from January to June 2019, were analyzed. Experienced operators, unaware of the study were left free of access site decision. Comparative demographic features and clinical outcomes were recorded during hospitalization.

RESULTS

LDRA was used in 30 patients, whereas 61 patients underwent a TF approach. Successful PPCI was achieved in high rates in both groups (LDR: 90% vs TF: 91.8%: p = 0.795). On admission, KILLIP (II, III) class was higher in the LDRA group (23.3% vs 3.4%), whereas stent thrombosis, arhythmias were higher in the TF group (0% vs 6.6% p = 0.151; 6.7% vs 18% p = 0.355 respectively). Puncture time was relatively similar between groups (28.63 vs 28.93 s p = 0.767). Fluoroscopy time, total radiation exposure and hospital duration was found lower in the LDRA group (10.11 vs 13.75 min p < 0.001; 917.87 vs 1940.91 mGy p < 0.001; 4.2 vs 6.2 days p = 0.024 respectively). In-hospital mortality was found higher in the TF group (0% vs 18% p = 0.013).

CONCLUSION

In the acute management of STEMI, LDRA access site can be a convenient alternative to TF approach with shorter hospital duration and complication rates.

Feasibility and Safety of the Distal Transradial Artery for Coronary Diagnostic or Interventional Catheterization

Background

This prospective study compared the success rate and safety of a distal transradial artery (dTRA) approach to that of the conventional transradial artery (TRA) for coronary angiography or percutaneous coronary intervention.

Methods

From January 2019 to April 2020, nine hundred consecutive patients (height < 190 cm) scheduled for coronary angiography or percutaneous coronary interventions were randomly and equally assigned to receive either dTRA or conventional TRA catheterization.

Results

Successful access was achieved in 96.00% and 96.67% of the dTRA and conventional TRA groups, respectively (P=0.814). Compared with the TRA group, patients in the dTRA experienced significantly less hemostatic band removal time (150.5 ± 50.5 cf. 210.6 ± 60.5 min, P=0.032); minor bleeding of the access site (2.44% cf. 6.44%, P=0.038); hemostatic band cost (USD; 0.1 cf. 59.4, P=0); and postprocedural radial artery occlusion (1.56% cf. 3.78%, P=0.035). A lower body mass index was a higher risk factor for dTRA access failure (odds ratio = 0.79, P=0.024), with a cutoff of 22.04 kg/m².

Conclusion

Compared to conventional TRA, dTRA had a comparable high success rate, with fewer associated complications. Clinicians should use the dTRA with caution in patients with low body mass index.

Distal transradial access for cardiac catheterization: A systematic scoping review

OBJECTIVE

Systematically review the literature for cardiac catheterization and coronary angiography via distal transradial access (dTRA) and its outcomes.

BACKGROUND

dTRA, via anatomical snuffbox, may have several advantages over conventional transradial access (cTRA) for percutaneous cardiac procedures, including easier left-sided access for aorto-coronary grafts, future proximal radial artery preservation, and patient and operator comfort. However, its procedural characteristics and safety profile remain unclear.

METHODS

Ovid MEDLINE and EMBASE were searched from inception to September 2018. Two authors independently performed two-stage selection and data extraction. Reports assessing the dTRA approach for cardiac intervention in adults reporting any outcomes were eligible. Descriptive summary statistics were calculated from pooled data.

RESULTS

A total of 19 publications comprising 4,212 participants undergoing dTRA were included. Mean age was 63.8 years, and 23.0% were female. dTRA was primarily undertaken for assessment of stable coronary artery disease (87.6%), with 41.7% for diagnostic procedures and 46.9% undergoing percutaneous coronary intervention. The overall success rate for undertaking the dTRA approach was 95.4% (69-100%). Complications occurred in 2.4% of cases, of which the leading complications were bleeding/hematoma (18.2%). Complication rates did not significantly differ between dTRA and cTRA. The occurrence of radial artery occlusion in patients undergoing dTRA was low (1.7%).

CONCLUSIONS

Observational data demonstrate that dTRA is a safe and feasible method for percutaneous cardiac procedures, with high rates of procedural success and low rates of complication. As data comparing dTRA with cTRA remain limited, future high-quality randomized comparative studies are required.

Distal radial approach: a review on achieving a high success rate

INTRODUCTION

The transradial approach is the standard for percutaneous coronary intervention (PCI). Moreover, to lead to the evolution of PCI, a new approach site was developed, namely the distal radial approach (dRA).

ANATOMY AND VESSEL DIAMETER

The vessel diameter of the distal radial artery is smaller than that of the forearm radial artery; hence, use of 1 Fr size or a sheath with a thinner outer diameter is recommended. Ultrasound examination before the procedure provides useful information on this matter.

PUNCTURE

There are two approaches to puncture: proximal site puncture of the distal radial artery and distal site puncture. Based on anatomical characteristics, the puncture angle is large on the former and small on the latter. Although a learning curve for the dRA puncture is needed, the use of ultrasound facilitates the process.

HEMOSTASIS

Using a hemostatic device dedicated to the dRA simplifies observation after PCI. Hemostatic devices for the conventional radial approach or simple bandage with an elastic band can be useful. Usually, less hemostasis time is needed for the dRA compared with the conventional radial approach.

SUCCESS RATE

Studies have shown high success rates of the dRA (approximately 88-99.5%).

ADVANTAGES AND DISADVANTAGES

Advantages of the dRA are patient comfort, short hemostasis time, less restraint for the patients after PCI, and easy observation at the ward. Disadvantages are the learning curve required for the puncture and the small diameter of the distal radial artery.

CONCLUSION

The dRA is a new approach site for PCI. Further research is warranted for the selection of suitable patients to undergo PCI through the dRA.

A comparative assessment of Dorsal radial artery access versus classical radial artery access for percutaneous coronary angiography-a randomized control trial (DORA trial)

OBJECTIVES

This is an open-label randomized control trial with a parallel assignment with single masking comparing patients undergoing coronary angiography via dorsal radial and classical radial access.

METHODS

Study done at three tertiary cardiac care centers for two years. A total of 970 patients were finally recruited for the study. Patients were randomly selected for dorsal radial artery access Group A (485 patients) and classical radial artery access Group B (485 patients) without any bias for age & sex.

RESULTS

On comparative assessment both techniques are found to be equal in terms of procedural success rate. While dorsal access was superior in terms of fewer incidences of forearm radial artery occlusion, radial artery spasm, less post-procedure persistence of pain, and hand clumsiness. In comparison to this, the number of puncture attempts and time to achieve post-procedure hemostasis is less in classical radial access.

CONCLUSION

So both techniques have pros and coins and it is the discretion of interventionists to adopt which technique.

Distal transradial access: a review of the feasibility and safety in cardiovascular angiography and intervention

BACKGROUND

Transradial access (TRA) has been considered as the default choice in cardiac catheterization. Although infrequent, vascular complications of this approach remain. Recently, the distal transradial approach (dTRA) in cardiac catheterization was reported by interventionalists.

METHODS

We retrieved the relevant literatures and reviewed the safety and feasibility of this novel approach in cardiac catheterization.

RESULTS

The dTRA for cardiac intervention has superior safety and satisfaction. As a novel approach for cardiac catheterization, access related complications should also be considered by operators, such as RAO, radial spasm, bleeding and haematoma, and injury of the superficial branch of the radial nerve.

CONCLUSIONS

The dTRA in cardiovascular angiography and intervention was safe and feasible.

Assessment of the conventional radial artery with optical coherent tomography after the snuffbox approach

BACKGROUND

This study aimed to evaluate acute injuries of the radial artery (RA) using optical coherence tomography (OCT) in patients who underwent coronary intervention via the snuffbox approach.

METHODS

Forty-six patients, who underwent coronary intervention and assessment of the conventional RA using OCT via the snuffbox approach, were enrolled from two university hospitals between August 2018 and August 2019.

RESULTS

The mean age of the patients was 65.1 years. In this study population, 6-French (Fr) sheaths were used. The mean diameter of the conventional RA was 2.89 ± 0.33 mm, and the mean lumen area of the conventional RA was 6.68 ± 1.56 mm2. Acute injuries of the conventional RA, after the snuffbox approach, were observed in 5 (10.9%) patients. Intimal tear was observed in the RA in 1 (2.2%) case. Intraluminal thrombi, without vessel injuries, were detected in the RA in 4 (8.7%) cases. However, medial dissection was not observed in the OCT analysis.

CONCLUSIONS

This retrospective OCT-based study showed that the diameter of the conventional RA was 2.89 mm and acute vessel injury of the conventional RA was rare in patients who underwent coronary intervention via the snuffbox approach.

An observational comparison of distal radial and traditional radial approaches for coronary angiography

Background

Several studies have recently reported regarding feasibility and safety of distal transradial access (d-TRA) in the anatomical snuff-box (ASB); however, literature comparing it with the conventional TRA at the wrist (w-TRA) is sparse. This study compares the technical efficiency and safety of ASB and wrist approaches for TRA for coronary angiography (CAG) and evaluates the radial artery (RA) anatomy at these sites.

Methods

Two hundred consecutive patients undergoing CAG via w-TRA or d-TRA (100 in each group) were investigated. The primary endpoint was comparison of procedural efficiency of the two methods, defined as CAG completion from the intended access site. The secondary endpoints assessed d-TRA approach in terms of achievement of successful cannulation, arterial puncture, access time (AT), and total procedure time (TPT) in comparison with the conventional method. Safety endpoints included radiation parameters and complications. Furthermore, in 112 normal adults, RA anatomy was assessed at wrist and at ASB.

Results

In d-TRA group, 77% patients achieved primary endpoint compared with 93% in w-TRA group (p = 0.004). The success of arterial puncture was comparable for d-TRA and w-TRA (93% and 99%, respectively; p = 0.065), but the cannulation rate was lower for d-TRA. Safety endpoints were similar in both the groups. AT and TPT were longer for d-TRA.

Conclusions

The ASB approach for CAG lowers the success rate and prolongs AT and TPT. The RA at ASB is smaller, has a curved course, and more anatomical variations than the RA at the wrist.

Distal Versus Conventional Transradial Artery Access for Coronary Angiography and Intervention: A Meta-Analysis

BACKGROUND

Distal transradial artery access (dTRA) through the anatomical snuffbox is a novel approach for performing coronary angiography and interventions. However, the safety and efficacy of dTRA as compared to conventional TRA (cTRA) remains unknown. We aim to evaluate the outcomes of dTRA versus cTRA for coronary angiography and intervention.

METHODS

Electronic search of the National Library of Medicine PubMed and Cochrane Library databases was performed until April 2019 for studies comparing the clinical outcomes of dTRA approach versus conventional TRA (cTRA) approach in coronary angiography and interventions. Random-effects DerSimonian-Laird risk ratios (RR) were calculated. The main outcome was failure of access site utilization. Other outcomes included access site hematoma, radial artery spasm, dissection, and occlusion.

RESULTS

Five studies (4 observational and 1 randomized controlled) with a total of 6746 patients (dTRA n = 3209 and cTRA n = 3537) were available for analysis. The failure rate was similar in dTRA and cTRA groups (5.26% versus 3.75%; RR = 1.36; 95%CI 0.41-4.48; p = 0.62). Similarly, no difference was observed between dTRA and cTRA in regards to access site hematoma (1.20% versus 1.24%, RR = 1.01; 95%CI 0.49-2.07; p = 0.99), radial artery spasm (1.42 versus 3.84%, RR = 0.91; 95%CI 0.32-2.62; p = 0.86), or radial artery dissection (0.11 versus 0.20%, RR = 0.63; 95%CI 0.18-2.16; p = 0.46). The rate of radial artery occlusion was lower with dTRA (2.30 versus 4.86%, RR = 0.51; 95%CI 0.32-0.81; p = 0.004) as compared to cTRA.

CONCLUSION

Distal TRA appears to be a safe and effective alternative to conventional TRA. The outcomes of this novel technique warrant further randomized studies.

Distal Radial Artery Access: The Future of Cardiovascular Intervention

Access sites for coronary intervention have been changing over the last several decades, from the femoral artery to the radial artery and then to the distal radial artery. Distal radial access, which was first used in 2017 and is still not recommended by the guidelines, shows a higher success rate and less complications than other sites; therefore, it might be the future for cardiovascular intervention. In this study, we reviewed almost all of the articles that are related to the distal radial access, from 2017 to present, and summarized the technique, success rate, advantages, disadvantages, and noncardiac use of this access site.