Small Radial Artery Research Articles

Feasibility and radial artery occlusion rate of sheathless distal transradial access using balloon guide catheters.

Distal transradial access (dTRA), performed through an anatomical snuffbox, minimizes post-procedural burdens of endovascular treatments. However, despite the benefits of balloon-guide catheters (BGCs), their use in dTRA is limited by their small radial artery diameter. Herein, we evaluated the feasibility and radial artery occlusion (RAO) rate of 8Fr BGCs used in sheathless dTRA. This retrospective study reviewed patients treated with sheathless dTRA using an 8Fr Optimo at a single center between July 2023 and May 2024. dTRA procedures were performed under general anesthesia in patients not requiring urgent treatment. The RAO was assessed using ultrasonography 24h after the procedure. The demographic and procedural characteristics were compared between the radial artery patency and occlusion groups. Of 170 patients, 50 underwent dTRA, and 43 (86%) completed the procedure. RAO occurred in 12/43 (28%) patients with dTRA. Univariate and receiver operating characteristic curve analyses demonstrated that the median radial artery diameter was significantly smaller in the RAO group (P < 0.001), with an optimal cut-off value of 2.4mm to predict RAO. Complications included minor cerebral ischemia in two patients, but no severe ischemia was observed. Sheathless dTRA using an 8Fr Optimo BGC is feasible, but the risk of RAO should be noted, particularly in patients with small radial artery diameters. This study suggests a radial artery diameter cutoff value of 2.4mm to predict RAO, aiding access decisions for large-bore BGC. Further multicenter prospective studies are warranted to confirm these findings and assess long-term outcomes.

Enhancing Guidewire Efficacy for Trans-radial Access: The EAGER Randomized Controlled Trial.

Background: The 1.5mm 'Baby J' hydrophilic narrow J tipped wire is a development of the standard 0.035" 3mm J tipped peripheral guidewire, designed to improve efficiency of transradial coronary procedures by safely navigating small caliber radial arteries to the aorta. There is currently a lack of evidence comparing the procedural success and safety of different peripheral guidewires used in transradial cardiac procedures. We compared the efficacy and safety of a narrow J tipped hydrophilic 0.035" wire (intervention - Radifocus™ 'Baby J' guidewire, TERUMO Co., Tokyo, Japan). versus standard fixed core (FC) 0.035" J wire (control). Methods: Investigator initiated, blinded, Australian, multicenter randomized trial in patients undergoing clinically indicated coronary angiography and/or PCI. Randomized 1:1 via sealed envelope method to use either the control or the intervention guidewire. The primary endpoint (technical success) was defined as gaining aortic root access with the randomized guidewire. Results: 330 patients were randomized between October 2022 - June 2023 (median age 69 years, 36% female, BMI 29 kg/m²). The primary endpoint was achieved more frequently in the intervention group [96% v 84%; mean difference 12% (95% CI 5.7-18.3); p<0.001]. Women assigned to the control wire experienced a higher failure rate compared to men (31% v 8% in men; p<0.001). Fluoroscopy time was significantly shorter in the baby J group (median 344 versus 491 seconds; p=0.024). The main mechanisms of failure using the control wire were radial artery spasm (15/26; 57%) and subclavian tortuosity (5/26; 19.2%). There were no differences in overall procedure times, MACE, or vascular complications between guidewires. Conclusions: A narrow 1.5mm J tipped hydrophilic guidewire resulted in greater technical success and reduced fluoroscopy time compared to the standard 3mm J tip non-hydrophilic guidewire. The guidewire is safe and demonstrated key incremental benefits for the trans-radial approach particularly in women.

Feasibility, efficacy, and safety of mechanical thrombectomy via sheathless transradial access as a first-line strategy: A case series

ObjectiveAlthough mechanical thrombectomy (MT) is primarily performed via transfemoral access (TFA), transradial access (TRA) is a potential alternative in older patients or those with tortuous vessels. However, the small radial artery diameter restricts the use of large-bore balloon guides and aspiration catheters, a limitation that may be overcome using the sheathless technique. Thus, we aimed to explore the feasibility, efficacy, and safety of sheathless TRA-MT as a first-line treatment approach for acute ischemic stroke. MethodsThis single-center retrospective case series included patients who underwent TRA-MT as first-line treatment between September 2020 and June 2023. Per our MT protocol, TRA was not the first-line approach in cases of left anterior circulation lesions with a type 3 aortic arch. We evaluated treatment effectiveness based on the successful recanalization rate, puncture-to-recanalization time, and modified first-pass effect; access route effectiveness based on the puncture-to-first-pass time and switch-to-TFA rate; and procedure safety based on procedure-related and severe puncture site complications. ResultsSheathless 8-F guide catheters were used in 68 % and large-bore aspiration catheters in 70 % of the procedures. Successful recanalization was achieved in 98 % of the patients, with a modified first-pass effect in 54 % of them. The median puncture-to-first-pass and puncture-to-recanalization times were 20.5 and 33 min, respectively. The rate of procedure-related complications was low (4 %), with no severe puncture site complications. ConclusionSheathless TRA-MT enabled the use of large-bore guide and aspiration catheters, providing a swift approach to the target and satisfactory outcomes, and might be an effective first-line treatment for acute ischemic stroke.

Routine preprocedural ultrasound in palpation versus ultrasound guided radial access for cardiac catheterization.

The radial first approach in cardiac catheterization is preferred for its benefits in patient comfort and recovery time. Yet, challenges persist due to characteristics like small, deep, calcified, and mobile radial arteries. Utilizing ultrasound before and during procedures can improve success rates. However, the adoption of its use is still limited and subject to debate. To utilize routine preprocedural ultrasound (US) and compare US guided with palpation guided radial access, focusing on operator efficiency and outcomes. Consenting adult patients undergoing elective radial cardiac catheterization were divided into palpation and US groups. Routine preprocedural assessment of radial artery characteristics was performed using handheld US. Baseline data, US findings, procedural outcomes, and clinical outcomes were compared in 182 participants (91 in each group). US guided radial access had significantly higher first pass success rates (76.92% vs. 49.45%, p 0.0001), fewer number of attempts (1.46 ± 1 vs. 1.99 ± 1.46, p 0.004), and shorter amount of time (93.62 ± 44.04 vs. 120.44 ± 67.1, p 0.002) compared with palpation guidance. The palpation group hadsignificantly higher incidence of spasm (15.38% vs. 3.3%, p 0.0052). Subgroup analysis indicated consistent benefits of US guidance, especially in calcified radial arteries. This prospective, nonrandomized, single-center study demonstrated that real-time procedural US improved the operator's time and effort and enhanced patient comfort compared with palpation. US guidance use was particularly favorable in the presence of calcifications observed on baseline preoperative US.

Comparison of Glidesheath Slender and Subcutaneous Nitrate Administration in Terms of Radial Artery Complications: A Retrospective Single-Center Experience.

The transradial route is used in most coronary procedures today. Although this method seems to be advantageous in terms of bleeding complications and patient comfort, the small radial artery diameter brings with it complications such as radial artery spasm and occlusion. It has been demonstrated in previous studies that subcutaneous nitrate administration dilates the radial artery. The Glidesheath Slender, which has a thinner outer wall than conventional sheaths, is another method that has been shown to reduce complications by reducing friction on the radial artery wall. Our aim was to compare these two methods in terms of complications. We retrospectively reviewed patients with complete clinical and radial Doppler ultrasound records who had undergone transradial interventions. We compared procedures using subcutaneous nitrate application plus conventional sheaths with procedures using the Glidesheath Slender sheath in terms of procedural and post-procedural complications. Eighty-seven patients in the subcutaneous nitrate group and 35 patients in the Glidesheath Slender group were included in the study. There were no significant differences between the two groups in terms of procedural and postprocedural complications (p = 0.511 and p = 0.333, respectively). In cases where a thin-walled sheath such as a Glidesheath Slender is not available, subcutaneous nitrate administration seems to be similar, especially in terms of preventing radial artery spasm.

Sonographic diagnosis and evaluation in patients with superficial radial arteries.

The superficial radial artery (SRA) is a rare congenital anomaly in the forearm. However, it can be detected incidentally via trauma, intraoperative findings, angiography, or ultrasonography. In addition, intra-arterial infusion of intravenous medications and difficulties in radial artery catheterization may occur in cases of the SRA. Between December 2016 and July 2020, anomalous branches of radial arteries were found incidentally in nine patients at the preoperative visit and identified during ultrasound-guided radial artery puncture in 21 patients when radial artery catheterization using the palpation method proved difficult. Ultrasound examinations were performed for diagnosis and evaluation of these 30 patients. All anomalous branches of the radial artery were SRAs; 11 (37%), 13 (43%), 6 (20%) were present on the right side, on the left side, and bilaterally, respectively. All SRAs ran close to the cephalic vein. The vascular diameters of the radial arteries were the smallest in the radial artery distal to the SRA bifurcation (followed by in the SRA) and the largest in the radial artery proximal to the bifurcation (p < .001). In two cases, color Doppler study revealed that both the blood flow and color Doppler signal of the SRA disappeared with compression of the radial artery proximal to the SRA bifurcation. Because the SRA runs very close to the cephalic vein, a tourniquet applied to the arm may easily lead to intravenous catheter misplacement into the SRA. In addition, the small radial artery distal to the SRA bifurcation causes difficulty in radial artery catheterization. Furthermore, SRA cases may have falsely normal Allen's test results. Therefore, the authors recommend that the SRA must be identified before vascular puncture for safe vascular catheterization in the forearm.

Operative Technique of Autogenous Forearm Loop Fistula

Autogenous AV access are preferred in all CKD patients due to good patency rates and lower risks of infection. Radiocephalic fistulas (RCF) are the first preferred access, but most patients have diseased and small diameter radial arteries. We would like to describe a technique of creating a forearm loop fistula, utilising a good forearm vein in patients with diseased radial arteries and failed RCF.

MICROSURGERY FOR THE CREATION OF ARTERIOVENOUS FISTULAS IN PATIENTS WITH RADIAL ARTERIES DIAMETER SMALLER THAN 1.6 MM

In End-stage Renal Disease patients, the distal forearm is the preferred site for hemodialysis access, however forearm vessels have small diameter and according to Guidelines a radial artery internal diameter smaller than 1.6-2 mm is strongly predictive of early failure of the arteriovenous fistula (AVF) because of stenosis and obstruction. It could happen for some patients to not be considered suitable for distal forearm AVF because of poor peripheral vessels, so in these cases the micrusurgical technique can be very helpful in handling such “inadequates” vessels for lower-arm fistula creation. This study is an investigation of long-term patency of distal radio-cephalic AVFs created under microscopic guidance by using small radial arteries (less the 1.6 mm diameter) in adult patients with chronic renal failure and without severe comorbidities. In a sample of 31 patients, at 1 year postoperatively, the mean primary patency rate was 67.7% (21 functioning AVFs out of 31) and that is quite the same result of AVFs’ made with arteries larger than 2 mm.

A novel 3-Fr guiding sheath for transradial access in aneurysm embolization: Technical note.

Neurointervention via transradial access (TRA) is challenging when the radial artery is narrow. We performed aneurysm embolization via TRA using a novel 3-Fr guiding sheath (GS) (Axcelguide; Medikit, Tokyo, Japan) with an outer diameter of only 1.76 mm for patients with a radial artery of inner diameter less than 2 mm, and described the whole procedure and pitfalls as a technical note. Here, we present two patients with radial arteries less than 2 mm. One patient had a narrow neck intracranial aneurysm at the bifurcation of the left vertebral artery and posterior inferior cerebellar artery, which was embolized with the primary coiling technique. The other was a patient with a wide-necked extracranial aneurysm in the cavernous portion of the right internal carotid artery, which was embolized with the transcell technique with stent. We utilized a 3-Fr GS, distal access catheter, and a 0.0165-inch microcatheter for coil embolization. All aneurysms were completely occluded, without neurological or puncture site-related complications including subcutaneous hematoma, radial artery occlusion, and vasospasm. This report provides the first description of neurointervention using a 3-Fr GS. The 3-Fr GS contributed to successful completion of TRA aneurysm embolization without neurological or puncture site-related complications in patients with radial arteries narrower than 2 mm. The 3-Fr GS may be useful to accomplish aneurysmal embolization via TRA even in patients with a small radial artery.

Abstract 10430: Radial First! Ulnar Next? Forearm Arterial Anatomy Study

Introduction: In patients with small Right Radial Artery ( RRA ), access site failure may result in a radial to femoral crossover. Methods: The arterial anatomy of the distal forearm was studied using ultrasound in 167 hospitalized patients. The radial and ulnar artery dimensions were imaged in triplicates. The average cross-sectional area (CSA) and average diameter (AD) were measured using open-source ImageJ software. Variations in distal forearm arterial anatomy (branches) were documented. Results: The mean CSA and AD for the largest of the bilateral radial and ulnar arteries - Largest Forearm Artery ( LFA ), were 5.4 ± 2.5 mm 2 (1.1 → 13.3 mm 2 ) and 2.6 ± 0.6 mm (1.2 → 4.1 mm) respectively. The mean CSA and AD for RRA were 4.8 ± 2.5 mm 2 (0.7 → 13.3 mm 2 ) and 2.4 ± 0.6 mm (0.9 → 4.1 mm). In 46% of patients, RRA was not the LFA. The ulnar artery was larger than the radial artery in 25% of patients in the right wrist and 29% in the left wrist. The left radial was larger than the right radial in 31% and the left ulnar was larger than the right ulnar in 42%. In 58% of patients, RRA was &lt; 2.5 mm (outer diameter of common radial access sheaths). In 24% of patients, RRA was &lt;2 mm. In patients with RRA &lt; 2.5 mm, 17% had another artery &gt;2.5 mm and 6% had another artery &gt; 3 mm. Men had 53% larger CSA compared to women. Smoking, intravenous drug use, diabetes, hyperlipidemia, peripheral vascular disease, chronic kidney disease (CKD), and hemodialysis predicted smaller-sized forearm arteries. CKD patients had 33% smaller CSA compared to patients without CKD. In 23 patients (14%), one or more of the forearm arteries had branches in the distal forearm. In 12 patients (7%), branches were seen in RRA. Conclusions: Right Radial Artery was not the largest forearm artery in almost half the patients. Right Radial Artery was smaller in size than common radial access sheaths in more than half of the patients. Of these patients, 17% had a different forearm artery &gt; 2.5 mm that could be accessed instead of Femoral Artery. Female sex and CKD predicted smaller forearm artery sizes increasing the risk of radial access failure. Ultrasound use is advisable to identify the best forearm artery for access and avoid accessing smaller accessory branches that were seen in 7% of right radial and 14% of one or more forearm arteries.

RailTracking: A Novel Technique to Overcome Difficult Anatomy During Transradial Approach.

We aim to investigate the safety and efficacy of a new technique, "RailTracking," in the management of challenging transradial routes during percutaneous coronary interventions (PCI). The transradial access (TRA) currently represents the access site of choice in PCI, but complex anatomy could lead to complications and access-site crossover. The assisted-tracking techniques described in the past (such as balloon-assisted tracking and pigtail-assisted tracking) are based on the concept of a "guiding tapered tip" to improve trackability. The RailTracking technique creates a tapered catheter tip using a dedicated device. We collected patient data from January 2021 to January 2022 in 2 high-volume centers using the RailTracking technique as a bail-out solution. A prospective analysis of the anatomical characteristics and outcomes of the study population was performed. Seventy-seven patients were included in the study. All patients presented with challenging anatomies; 35.1% of the patients (n = 27) had small radial arteries, 19.5% (n = 15) had significant radial tortuosity, 2.6% (n = 2) had significant brachial tortuosity, 2.6% (n = 2) had subclavian tortuosity, and 1.29% (n = 1) had a critical subclavian lesion. In addition, 38.9% presented with severe radial spasm. The procedural success rate of the RailTracking technique was 98.7% (76/77 patients). The only case of failure presented with calcifications and a critical lesion in the subclavian artery. However, no periprocedural vascular complications occurred. This new technique appears safe, with a radial artery occlusion rate of 3.89% (n = 3) at 1-month follow-up. The new RailTracking technique improves catheter crossing in challenging anatomies and seems safe and effective in cases of failure with currently available approaches.

Modified long-axis in-plane ultrasound-guided radial artery cannulation in adult patients: A randomized controlled trial

IntroductionFor adults with small radial arteries, ultrasound-guided radial artery cannulation remains challenging and the relevant data is currently lacking. The study aimed to test the hypothesis that modified long-axis in-plane ultrasound guidance (M-LAIP) would improve success rates of radial artery cannulation in this population. Patients and methodsThis was a prospective, randomised, and controlled clinical study that enrolled 201 adult patients with diameters of the radial artery less than 2.2 mm. Patients were randomised to M-LAIP, short-axis out-of-plane (SAOP), or conventional palpation (C-P) group according to different approaches of radial artery cannulation (M-LAIP, SAOP, and C-P). Outcome measurements included the success rate, cannulation time, and cannulation-related adverse events. ResultsThe cannulation success rate was significantly higher in the M-LAIP group than in the SAOP or C-P groups (first success rate: 80.3% vs. 53.8% or 33.8%; P < 0.001; total success rate: 93.9% vs. 78.5% or 50.8%; P < 0.001). Total cannulation time in the M-LAIP group was shorter than that in the SAOP group (P = 0.002) or the C-P group (P < 0.001). The rates of posterior wall puncture and haematoma in the M-LAIP group were lower than that in the SAOP group or C-P group (P < 0.008). ConclusionThe use of the M-LAIP approach significantly improved the success rate of radial artery cannulation, shortened procedure time, and lowered the rates of posterior wall puncture and haematoma in adults with radial artery diameters less than 2.2 mm, compared with that achieved by the SAOP or C-P approach.

Angiographic evaluation of radial artery injury after transradial approach for percutaneous coronary intervention

The transradial approach for percutaneous coronary intervention (TRA-PCI) has been increasingly gaining popularity in clinical practice. However, its association with risk for long-term radial artery injury has not been yet thoroughly defined. We retrospectively examined the patients undergoing radial artery angiography (RAG) after TRA-PCI to determine the incidence and risk factors of radial artery injury. The study included 558 patients undergoing follow-up radial artery angiography at 12 month after TRA-PCI. Radial artery injury occurred in 140 patients (25%) with 3 distinct morphological patterns: focal radial artery stenosis (RAS) P.7,7: in 7 patients (1%), diffuse radial artery stenosis (RAS) in 78 patients (14%), and radial artery occlusion (RAO) in 55 patients (10%). Patients with RAS/RAO were more likely to be female, had smaller height and body weight, smaller body mass index and smaller body surface area (BSA) as compared with those without RAS/RAO. Multivariable logistic regression analysis identified BSA (odds ratio, 1.34 per 0.1 m2 increase; 95% confidence interval, 1.07–1.71; p = 0.01) and a history of TRA-PCI (odds ratio, 2.35; 95% confidence interval, 1.16–5.08; p = 0.017) as independent predisposing factors of radial artery injury. In a sub-analysis of 323 patients undergoing both pre-PCI RAG and follow-up RAG, pre-PCI radial diameter as well as BSA and a history of TRA-PCI were independently associated with radial artery injury. Long-term injury after TRA-PCI is considerably common and care should be paid for RAS/RAO, especially for those patients with lower BSA, history of TRA-PCI and small radial artery diameter.

Heparin-free distal radial artery approach to cardiac catheterisation and the small radial recurrent artery.

Radial artery access has transformed cardiac catheterisation, allowing it to be performed in a daycase setting, saving both hospital beds, and nursing care costs. However, there are two common and seemingly diametrically opposite complications. These are radial artery occlusion and forearm haematoma; the former could be reduced by heparin, but at the expense of precipitating the latter. These complications increase proportionally to the size of radial artery sheath used. Interestingly, by cannulating the radial artery more distally beyond its bifurcation in the hand, the distal radial approach appears to be the 'one stone, two birds' or the synchronous Chinese idiom, 'yīshí'èrniăo's' solution, reducing both complications at the same time. Extending this further and downsizing to a 4Fr catheter system, heparin use could be spared altogether, without complications, and haemostasis achieved with short manual pressure at the puncture site. Hence, further cost savings by foregoing commercial compression bands, and abolishing access site care for nurses. We illustrate the above strategy in a patient with challenging radial anatomy, made simple and easy.

Safety and feasibility of ulnar artery access for neuroangiography and neurointervention: a case series

BackgroundRadial access has become popular among neurointerventionalists because it has favorable risk profiles compared with femoral access. Difficulties in accessing or navigating the radial artery have been viewed as a...

Radial artery diameterand and age related functional maturation of the radio-cephalic arteriovenous fistula

BackgroundPrevious studies have not described the relationship between reducing radial artery diameter as well as increasing age and functional maturation of the radio-cephalic arteriovenous fistula (RCAVF) and no data identify these as linear relationship. The objective of this study was to perform trend analysis to assess these aspects.MethodsOur retrospective cohort study enrolled and analyzed 353 follow-up cases that underwent first AVF creation. The artery and vein sizes were measured by ultrasound. We performed follow-up, a minimum of 3 months after surgery. Multivariable logistic regression analysis was used to identify independent risk factors inmaturation. Participant age was categorized into four groups (age ≤ 29, 30–49, 50–69, and 70–90 years). Radial artery diameter was categorized into four groups (≤ 1.9, >1.9 and ≤ 2.1, >2.1 and ≤ 2.4, >2.4 mm) according to median and interquartile ranges. We adjusted for confounders in four logistic models, and primary analyses were based on building ordered category models and tested P values for trends to estimate the relationship of radial artery diameter and each 20-year increase in age with risk of maturation.ResultsThe mature RCAVF group included 301 cases, and the immature group included 52 cases. Radial artery diameter, age, and diabetes were independent risk factors of maturation. Odds ratios (ORs) associated with maturation reduced with increasing age, while ORs increased with increasing radial artery diameter. P values for trends(<0.05) were observed in all four models. A reduction in radial artery diameter and higher age were significantly associated with a higher incidence of immaturity after adjusting the multivariate models. The risks of immaturation were increased by more than 1.54 fold for each 20-year increase and increased by more than 1.34 fold for the smaller radial artery diameter group.ConclusionOur findings suggest that a significantly higher immaturity risk of RCAVF was associated with increasing age and a reduction in radial artery diameter. Our study identified a linear exposure-response relationship of age and radial artery diameter with immaturity incident. A careful selection of patients will be helpful in improving AVF functional maturation.

P6522Overcoming anatomic challenges to transradial access in STEMI patients

Abstract Background Transradial access is associated with fewer access-related complications, earlier discharge and lower mortality, being the preferred route to perform coronary angiogram and interventions due to its safety and cost effectiveness in STEMI patients. However, the radial artery is smaller, more superficial and thinner than the femoral artery and a percentage of patients ranging from 14% to 27% have a radial artery that is smaller than a 6-French introducer, which sometimes makes angioplasty difficult. Purpose This study reports our initial experience with the 5F straight (STR) flush catheter, which can be used as a “child” type rapid exchange catheter inside the 6F guiding catheter, creating a distal tip transition, facilitating angioplasty in transradial coronary interventions when the radial artery is small, tortuous or as severe spasm that impedes advancement of guiding catheter after successful angiography with 5F catheter. Methods We analysed, retrospectively, 1510 STEMI patients (pts) admitted in our catheterization laboratory, from August of 2010 to October 2017. Of these patients, 95 (6.3%) pts with problems in advancing a 6F guiding catheter, were submitted to this technique and a direct crossover to a femoral approach was performed in 36 pts (2.4%). This technique consists in the use of longer 5F STR flush catheter in order to overcome the larger distal tip of the 6F guiding catheter through the radial access, employing a 5-in-6 F technique. Results In 89 of 95 patients (93.7%), this new technique was successful, with a mean reperfusion time since arrival to the catheterization laboratory of 24.5±9.9 minutes. Of the pts submitted to this technique the majority were female 51 (57.3%) and the mean age was 67±14.3 years. Angioplasties were performed in the left main (2; 2.3%), left anterior descending (36; 40.4%), left circumflex artery (8; 9.0%), right coronary artery (40; 44.9%), right posterior descending artery (1; 1.1%) and obtuse marginal branch (2; 2.3%). No complications in arterial access were seen. Throughout these years of study, the need for crossover to femoral approach has decreased with the learning of this technique. The time until reperfusion since catheterization laboratory arrival was 29.3±9.5 minutes when there was a crossover, being statistically higher than with the radial procedure with the STR technique (p&lt;0.017). Conclusion This new technique may be a simple and useful approach to perform primary PCI through transradial access in patients with small diameter radial arteries, allowing a reduction of crossover to femoral access, which translates into a lower risk of vascular complications and shorter reperfusion time, that may influence the prognosis of STEMI patients.

Influence of remote ischemic conditioning on radial artery occlusion.

This study aimed to explore the influence of remote ischemic conditioning (RIC) on radial artery occlusion (RAO) and distinguish the risk factors for RAO. A total of 640 consecutive patients who prospectively underwent transradial artery coronary angiography (TRACA) (322 patients received RIC before TRACA) were enrolled. RIC was not performed in 318 patients. RAO was estimated using Doppler ultrasonography after the procedure. Patients were divided into two groups according to the protocol of RIC: RIC and non-RIC. The rate of RAO was significantly lower in the RIC group than in the non-RIC group. Patients were divided into two groups according to the patency of radial artery: radial artery patency (RAP) and RAO. The radial artery diameter was significantly narrower in the RAO group (2.31 ± 0.53) than in the RAP group (2.59 ± 0.47). The rate of applying β-blocker was significantly higher in the RAP group (69%) than in the RAO group (41%). The rate of applying trimetazidine was significantly higher in the RAP group (49.1%) than in the RAO group (17.6%). The multiple logistic regression analysis using radial artery diameter, RIC, β-blocker, and trimetazidine treatments revealed that small radial artery diameter, lack of β-blockers, and RIC were independent predictors of RAO. RIC might help in improving the rate of RAO. The multiple logistic regression analysis showed that the lack of β-blockers, RIC, and small radial artery diameter were independent predictors of RAO.

Effect of transient ulnar artery compression on radial artery diameter.

The transradial approach is widely preferred in coronary procedures. A small radial artery diameter (RAD) is the most important factor affecting successful access. Various maneuvers and medications have been used to increase the RAD and thereby facilitate RA cannulation. Ulnar artery compression (UAC) for 30 min has been indicated to be effective in increasing the RAD and facilitating RA access. The aim of the present preliminary study was to assess the effect of transient UAC for 1 min on the RAD. A total of 151 patients were included in the present study. RA ultrasonography was performed at the level of the wrist. The UA was compressed for 1 min. The RAD was measured at baseline, at the end of UAC and at 1 min thereafter. The results indicated that the RAD was significantly smaller in diabetic vs. non-diabetic patients (2.35±0.43 vs. 2.50±0.39 mm, P=0.024) and in women vs. men (2.25±0.38 vs. 2.56±0.38 mm, P<0.001). At the end of UAC, the RAD was increased compared with that at baseline (2.45±0.41 vs. 2.62±0.41 mm, P<0.001), but it started to decrease thereafter, and the RAD measured at 1 min after stopping UAC was significantly smaller (2.62±0.41 vs. 2.55±0.40 mm, P<0.001), while remaining significantly larger than that at baseline (P<0.001). The RA peak systolic flow velocity also increased significantly during UAC (35.3±8.9 vs. 60.3±19.2 cm/sec; P<0.001). In conclusion, Transient UAC for 1 min significantly increased the RAD and the peak systolic flow velocity. Further studies with clinical endpoints are required for further exploration of the feasibility of this approach.

Transulnar cardiac catheterization and percutaneous coronary intervention: techniques, transradial comparisons, anatomical considerations, and comprehensive literature review.

Ulnar arterial access for cardiac catheterization and intervention is an alternative approach compared with radial or femoral access. Ulnar access is infrequently performed since the radial artery is readily palpable and is commonly used worldwide to minimize vascular complications from femoral access. Nevertheless, ulnar access provides a suitable access site in patients who are poor candidates for femoral access, have pre-existing radial occlusion, radial artery hypoplasia or hyperplasia from prior radial artery procedures, radial stenosis, radial loops, radial tortuosity, small radial arteries, and/or have future need for radial graft for dialysis or coronary artery bypass graft. Furthermore, femoral access is the standard default option if radial access fails. Consequently, learning ulnar access provides a suitable forearm alternative to avoid femoral access when deemed high risk or undesirable. This review discusses the techniques of ulnar access, advantages and disadvantages of ulnar versus radial access, the clinical trials on ulnar cardiac catheterization and its associated complications.