Comparison of radiation exposure associated with transradial and transfemoral access: An updated meta-analysis.

OBJECTIVES: To assess differences in radiation exposure between transradial access (TRA) and transfemoral access (TFA) for coronary procedures. BACKGROUND: TRA is associated with increased radiation exposure as compared to TFA. We compared radiation exposure between the two access sites. METHODS: Databases were searched from June 2014 to August 2021 for randomized controlled trials (RCTs) reporting coprimary outcomes of fluoroscopy time (FT) and/or dose area product (DAP) comparing TRA with TFA. Meta-regression was performed to assess the behavior of weighted mean difference (WMD) in FT from 1995 to 2021. Observational study data was used for corroborative evidence. RESULTS: Data from 8 RCTs (11,611 patients) showed the WMD of FT was 0.62 min (37 s) (95% confidence interval [CI]: [0.08-1.17], p = 0.023) in favor of TFA, WMD in DAP (9169 patients) was 1.94 Gy.cm2 (95% CI: [-2.1 to 5.9], p = 0.35) showing no significant difference. Pooled data from OBS and RCTs (83,990 patients) showed a similar trend. Studies from outside US between 1995 and 2021 showed WMD of FT between TRA and TFA of 0.88 min (52 s) (95% CI: [0.67-1.09], p = 0.005) versus 2.1 min (126 s) (95% CI: [1.38-2.8], p = 0.005) for US in favor of TFA. Meta-regression showed a declining WMD of FT between TRA and TFA from 1.6 min (96 s) in 1996 to 0.5 min (30 s) in 2020 with the lower limit of CI crossing the zero line in 2019. CONCLUSION: Radiation exposure between TRA and TFA continues to decrease overtime and is becoming clinically nonsignificant.

Safety and Efficacy of Robotic-Assisted PCI.

PURPOSE OF REVIEW: Robotics has been used in multiple areas of procedural medical intervention. Robotic percutaneous coronary intervention (PCI) has been available since 2004. Its adoption has been slow with initial application in simple cases. RECENT FINDINGS: With increasing adoption, robotic PCI has been applied to a broader variety of coronary substrates with demonstration of safety and efficacy. Improvements in the robotic console with future generation devices should add to the utility of this platform. Robotic PCI advances the innovations in endovascular space into a different dimension, removing the dependence of the procedure on patient-operator ergonomics and likely operator skill.

Association between distance from the radiation source and radiation exposure: A phantom-based study.

OBJECTIVES: The study evaluated the association between distance from radiation source and radiation exposure. BACKGROUND: Radiation exposure during medical procedures is associated with increased risk of cancer and other adverse effects. METHODS: An American National Standards Institute phantom was used to study the relationship between measured entrance surface exposure (MESE) and distance from the X-ray source in postero-anterior, left anterior oblique, and right anterior oblique projections. Three distance settings for table height were evaluated with "low" defined as 52 cm, "mid" 66 cm, and "high" 80 cm from the focal point of the X-ray source. Air-kerma and dose-area product measurements were recorded. Operator exposure with each of these conditions was measured, in a short operator (150 cm) as well as in a tall operator (190 cm). RESULTS: Aggregate results for the three projections were as follows. MESE (µGy/frame) significantly decreased as table-height increases (median, interquartile range, p-value) (low table-height 192.5 [122.4-201.2], mid table-height 105.8 [82.7-115.8], and high table-height 71.7 [58.4-75], p < .0005). The operator exposure (µGy/frame), significantly increased as the table-height increased (low table-height 0.0943 [0.0598-0.1157], medium table-height 0.1128 [0.0919-0.1397], and high table-height 0.158 [0.1339-0.2165], p < .0005). A shorter operator received higher radiation exposure compared to a taller operator (short operator 0.1405 [0.1155-0.1758] and tall operator 0.0995 [0.0798-0.1212], p < .0005). CONCLUSIONS: Increasing table-height is associated with a significant decrease in MESE. Operator radiation exposure increases with increasing table-height and shorter operators receive greater radiation exposure compared to taller operators.

SCAI expert consensus statement update on best practices for transradial angiography and intervention.

Transradial angiography and intervention continues to become increasingly common as an access site for coronary procedures. Since the first "Best Practices" paper in 2013, ongoing trials have shed further light onto the safest and most efficient methods to perform these procedures. Specifically, this document comments on the use of ultrasound to facilitate radial access, the role of ulnar artery access, the utility of non-invasive testing of collateral flow, strategies to prevent radial artery occlusion, radial access for primary PCI and topics that require further study.

Radial versus femoral approach for saphenous vein grafts angiography and interventions.

BACKGROUND: Coronary angiography and intervention to saphenous venous grafts (SVGs) remain challenging. This study aimed to investigate the feasibility and safety of the radial approach compared to femoral access in a large cohort of patients undergoing SVG angiography and intervention. METHODS: Data from 1,481 patients from Canada, United States, and Spain who underwent procedures between 2010 and 2016 were collected. Patients must have undergone SVG coronary angiography and/or intervention. Demographics, procedural data, and in-hospital complications were recorded. RESULTS: Procedures were undertaken by either the radial (n = 863, 211 intervention) or femoral (n = 618, 260 intervention) approach. The mean number of SVGs per patient was similar between groups (radial 2.3 ± 0.7 vs femoral 2.6 ± 1.1, P = .61), but the radial group required a fewer number of catheters (2.6 ± 1.7 vs 4.1 ± 1.1, P < .001). Fluoroscopy time was comparable between groups, and there was a trend toward lower contrast volume in the radial group (P = .045). Overall, the total dose of heparin was significantly higher in the radial group (P < .001); however, radial patients experienced significantly less access-site bleeding complications (P < .001). Outpatients undergoing radial SVG interventions had a higher likelihood of a same-day discharge home (P < .001). CONCLUSIONS: Radial access for SVG angiography and intervention is safe and feasible, without increasing fluoroscopy time. In experienced centers, radial access was associated with fewer catheters used, lower contrast volume, and lower rate of vascular access-site bleeding complications. Moreover, outpatients undergoing SVG percutaneous coronary intervention though the radial approach had a higher likelihood of a same-day discharge home.

Contemporary transradial access practices: Results of the second international survey.

OBJECTIVES: To gain insight into current practice of transradial angiography and intervention in the United States and around the world. BACKGROUND: Transradial access (TRA) has grown worldwide. In a prior survey, there was significant practice variation and there was minimal US participation which limited the generalizability to US operators. METHODS: We used an internet-based survey software program to solicit input from practicing interventional cardiologists from the United States and around the world. US operators were compared with outside the United States (OUS) operators and respondent-level comparisons were made with the prior survey to assess for temporal changes in practice. RESULTS: Between August 2016 and January 1, 2017, 125 interventional cardiologists completed the survey representing 91 countries with the United States having 449 (39.9%) respondents. Preprocedure, noninvasive testing for collateral circulation is used more commonly in the United States (54.1%) than around the world (26.6%) but its use has decreased since 2010. In the US, 48.8% of operators never use ultrasound and 92.6% of OUS operators never use it; only 4.4% overall use ultrasound in >50% of cases. Use of bivalirudin has decreased in the US and OUS. Nearly, 30% of operators do not assess for radial artery patency following hemostasis. US respondents used TRA less commonly for primary PCI for STEMI than their global counterparts. CONCLUSIONS: There is wide variation in how TRA procedures are performed including relatively low rates of adherence to practices that are known to improve outcomes. Further education aimed at increasing use of best practices will impact patient outcomes.

Determinants of operator radiation exposure during percutaneous coronary procedures.

BACKGROUND: Radiation exposure is an important issue for interventional cardiologists that is often underevaluated. Our aim was to evaluate determinants of operator radiation exposure during percutaneous coronary procedures. METHODS: The RADIANT (NCT01974453) is a prospective, single-center observational study involving 4 expert operators and 2 fellows performing percutaneous coronary procedures. The operator radiation dose was evaluated using dedicated electronic dosimeters in 2,028 procedures: 1,897 transradial access (TRA; 1,120 right and 777 left TRA) and 131 transfemoral access (TFA). RESULTS: In the whole population, operator radiation dose at the thorax did not differ between TFA (9µSv [interquartile range 5-18µSv]) and TRA (9µSv [4-21µSv]), but after propensity score matching analysis, TFA showed lower dose (9µSv [5-18µSv]) compared with TRA (17µSv [9-28µSv], P<.001). In the whole transradial group, left TRA (5µSv [2-12µSv]) was associated with significant lower operator dose compared with right TRA (13µSv [6-26µSv], P<.001).The use of adjunctive protective pelvic drapes was significantly associated with lower radiation doses compared with procedures performed without drapes (P<.001). Among the operators, an inverse relation between height and dose was observed. Finally, left projections and the use of angiographic systems not dedicated for coronary and high frame rates were all associated with a significant higher operator radiation exposure. CONCLUSIONS: In a high-volume center for transradial procedures, TFA is associated with lower operator radiation dose compared with TRA. The use of adjunctive anti-rx drapes seems a valuable tool to reduce the higher operator radiation exposure associated with TRA.

Interosseous artery as an access artery in case of late radial artery occlusion.

We report a new technique of arterial access through the ipsilateral interosseous artery in a case of late radial artery occlusion (RAO). RAO, although not frequent, is a limiting iatrogenic complication after transradial intervention (TRI) and precludes repeat use of the same radial artery for future procedures. Our technique involves obtaining access to the ipsilateral radial artery (RA) in the distal postocclusion segment and use of collateral channel between this segment and the interosseous artery (IOA) for advancing a guidewire and sheath in the IOA lumen and in brachial artery thereafter. © 2017 Wiley Periodicals, Inc.

New technique for treatment of postcatheterization radial artery pseudoaneurysm.

We report a new technique for treatment of radial artery pseudoaneurysm (RAP) caused by transradial access (TRA) for coronary angiography. Traditional extrinsic compression with radial flow cessation leads to a local milieu likely associated with an increase in probability of radial artery occlusion (RAO). Our technique involves obtaining ipsilateral radial artery access distal to the neck of the RAP followed by a prolonged sheath dwell time covering the neck of the RAP which allows the RAP sac to thrombose and maintains radial artery lumen patency. © 2016 The Authors. Catheterization and Cardiovascular Interventions Published by Wiley Periodicals, Inc.

Radiation exposure in relation to the arterial access site used for diagnostic coronary angiography and percutaneous coronary intervention: a systematic review and meta-analysis.

BACKGROUND: Transradial access for cardiac catheterisation results in lower bleeding and vascular complications than the traditional transfemoral access route. However, the increased radiation exposure potentially associated with transradial access is a possible drawback of this method. Whether transradial access is associated with a clinically significant increase in radiation exposure that outweighs its benefits is unclear. Our aim was therefore to compare radiation exposure between transradial access and transfemoral access for diagnostic coronary angiograms and percutaneous coronary interventions (PCI). METHODS: We did a systematic review and meta-analysis of the scientific literature by searching the PubMed, Embase, and Cochrane Library databases with relevant terms, and cross-referencing relevant articles for randomised controlled trials (RCTs) that compared radiation parameters in relation to access site, published from Jan 1, 1989, to June 3, 2014. Three investigators independently sorted the potentially relevant studies, and two others extracted data. We focused on the primary radiation outcomes of fluoroscopy time and kerma-area product, and used meta-regression to assess the changes over time. Secondary outcomes were operator radiation exposure and procedural time. We used both fixed-effects and random-effects models with inverse variance weighting for the main analyses, and we did confirmatory analyses for observational studies. FINDINGS: Of 1252 records identified, we obtained data from 24 published RCTs for 19 328 patients. Our primary analyses showed that transradial access was associated with a small but significant increase in fluoroscopy time for diagnostic coronary angiograms (weighted mean difference [WMD], fixed effect: 1·04 min, 95% CI 0·84-1·24; p<0·0001) and PCI (1·15 min, 95% CI 0·96-1·33; p<0·0001), compared with transfemoral access. Transradial access was also associated with higher kerma-area product for diagnostic coronary angiograms (WMD, fixed effect: 1·72 Gy·cm(2), 95% CI -0·10 to 3·55; p=0·06), and significantly higher kerma-area product for PCI (0·55 Gy·cm(2), 95% CI 0·08-1·02; p=0·02). Mean operator radiation doses for PCI with basic protection were 107 µSv (SD 110) with transradial access and 74 µSv (68) with transfemoral access; with supplementary protection, the doses decreased to 21 µSv (17) with transradial access and 46 µSv (9) with transfemoral. Meta-regression analysis showed that the overall difference in fluoroscopy time between the two procedures has decreased significantly by 75% over the past 20 years from 2 min in 1996 to about 30 s in 2014 (p<0·0001). In observational studies, differences and effect sizes remained consistent with RCTs. INTERPRETATION: Transradial access was associated with a small but significant increase in radiation exposure in both diagnostic and interventional procedures compared with transfemoral access. Since differences in radiation exposure narrow over time, the clinical significance of this small increase is uncertain and is unlikely to outweigh the clinical benefits of transradial access. FUNDING: None.

Impact of access site choice on outcomes of patients with cardiogenic shock undergoing percutaneous coronary intervention: A systematic review and meta-analysis.

BACKGROUND: The benefit of transradial access (TRA) in patients with cardiogenic shock (CS) is uncertain. We sought to determine the benefits of TRA in patients with CS undergoing coronary angiography/intervention. METHODS: MEDLINE, Embase, Cochrane Central, and electronic databases were searched for studies that assessed the following: (1) patients with CS who underwent percutaneous coronary intervention (PCI) and (2) the association between choice of arterial access, 30-day all-cause mortality, and 30-day major adverse cardiac and cerebral events (MACCEs) using random-effects model. RESULTS: From 3,652 retrieved citations, 8 studies involving 8,131 patients with CS undergoing PCI (via TRA: 2,321 patients, via TFA: 5,810 patients) were included. Transradial access was associated with significantly reduced risk for all-cause mortality (unadjusted: risk ratio [RR] 0.60, 95% CI 0.52-0.71, P < .001, I(2) = 29%, 8 included studies; adjusted: RR 0.55, 95% CI 0.46-0.65, P < .001, I(2) = 0%, 6 included studies) and MACCE (unadjusted: RR 0.68, 95% CI 0.63-0.73, P < .001, I(2) = 0%, 6 included studies; adjusted: RR 0.63, 95% CI 0.52-0.75, P < .001, I(2) = 0%, 4 included studies) at 30 days when compared with TFA. CONCLUSIONS: Transradial access is associated with reduced mortality and MACCE at 30 days in patients with CS undergoing PCI. Considering the possible influence of selection bias on the effect estimate in our analysis, randomized controlled trials are needed to better assess this association.

A novel nonpharmacologic technique to remove entrapped radial sheath.

Radial artery access for performance of coronary and peripheral diagnostic as well as interventional procedures is on the rise. With increasing adoption comes the expected increase in procedural complications. We describe a novel, simple, and effective nonpharmacologic solution for sheath entrapment related to pharmaco-resistant radial artery spasm. © 2014 Wiley Periodicals, Inc.

4Fr in 5Fr sheathless technique with standard catheters for transradial coronary interventions: technical challenges and persisting issues.

OBJECTIVES: To evaluate the feasibility and potential benefits of performing sheathless 5Fr transradial percutaneous coronary interventions (PCI) using 4Fr diagnostic catheters as dilators. BACKGROUND: There is a direct association between artery-catheter mismatch and risk of radial artery occlusion. METHODS: We recruited 130 patients who underwent 4Fr sheathless diagnostic angiography with super torque (Cordis Corporation, USA) catheters followed by ad hoc PCI. To facilitate skin and vessel penetration, the Judkins right catheter (110 cm) was inserted inside the 5Fr guiding catheter (100 cm) as dilator. RESULTS: The mean age of patients was 63±12 years with 74% of males. Unfractionated heparin monotherapy was used in 84%, bivalirudin in 12%, and platelet glycoprotein 2b/3a inhibitors in 13%. Right radial artery was used in 99%. In three cases, no PCI was performed (FFR) and in two (1.5%) cases, a sheath was required after guiding catheter insertion due to local bleeding. In six cases (4.6%), upscale to 6Fr sheathed approach was required. No spasm occurred. Overall procedural success was achieved in 114/119 (96%) cases, including left main PCI, bifurcation PCI in 10 (8%) cases, CTO in 5 (4%) and IVUS use in 6 (5%) cases. Immediately after hemostasis completion, duplex ultrasound showed normal flow in 76%, occlusive thrombus in 13%, pseudo-aneurysmal dilatation in 11% and local hematoma surrounding puncture site in 20%. Hemoglobin dropped from 138±19 g/l to 131±16 g/l 4-6 hours after PCI. CONCLUSION: Using 4Fr diagnostic catheters as dilators, simple and complex PCI can be performed with standard 5Fr guiding catheters as sheathless techniques. However, suboptimal transition between diagnostic and guiding catheters likely creates radial artery trauma leading to frequent occlusive thrombus and hematoma surrounding the radial artery.

Design and rationale of the TOTAL trial: a randomized trial of routine aspiration ThrOmbecTomy with percutaneous coronary intervention (PCI) versus PCI ALone in patients with ST-elevation myocardial infarction undergoing primary PCI.

BACKGROUND: A major limitation of primary percutaneous coronary intervention (PPCI) for the treatment of ST-elevation myocardial infarction (STEMI) is impaired microvascular perfusion due to embolization and obstruction of microcirculation with thrombus. Manual thrombectomy has the potential to reduce distal embolization and improve microvascular perfusion. Clinical trials have shown mixed results regarding thrombectomy. OBJECTIVE: The objective of this study is to evaluate the efficacy of routine upfront manual aspiration thrombectomy during PPCI compared with percutaneous coronary intervention alone in patients with STEMI. DESIGN: This is a multicenter, prospective, open, international, randomized trial with blinded assessment of outcomes. Patients with STEMI undergoing PPCI are randomized to upfront routine manual aspiration thrombectomy with the Export catheter (Medtronic CardioVascular, Santa Rosa, CA) or to percutaneous coronary intervention alone. The primary outcome is the composite of cardiovascular death, recurrent myocardial infarction, cardiogenic shock, or new or worsening New York Heart Association class IV heart failure up to 180 days. The trial uses an event-driven design and will recruit 10,700 patients. SUMMARY: The TOTAL trial will determine the effect of routine manual aspiration thrombectomy during PPCI on clinically important outcomes.

Operator's procedure volume and not years of experience, determine needle to balloon time in primary percutaneous coronary intervention.

OBJECTIVE: This study aimed at evaluating operator and procedural variables affecting needle to balloon time in primary percutaneous coronary intervention. BACKGROUND: The relationship between operator's variables with needle to balloon time is unknown. METHODS: A total of 399 consecutive patients from 06/2010 to 03/2012 presenting with ST-elevation myocardial infarction in a community medical center were included in the study. Operator experience was calculated in number of years in interventional practice and operator procedure volume in number of percutaneous coronary intervention procedures performed annually. The time of arrival was divided into regular hours (7 am to 4 pm) and off hours (4 pm to 7 am) on weekdays and the entire duration on weekends and holidays. RESULTS: The average patient age was 65 years and 59% were males. The mean needle to balloon time was 18.53 ± 8 min. There was no difference in needle to balloon time between patients presenting during regular hours compared to those presenting during off hours (18.19 ± 6.88 vs. 18.93 ± 9.13, P > 0.5). Operator experience (coefficient = -0.10, P = 0.03) and procedure volume (coefficient = -0.63, P < 0.0001) showed negative correlation with needle to balloon time. In multivariate analysis after adjusting for access sites and operator experience, procedure volume was the only independent predictor of needle to balloon time (P < 0.001). CONCLUSION: Operator procedure volume and not the years of experience, determine the needle to balloon time in patients undergoing primary percutaneous coronary intervention. Operator performance as assessed by needle to balloon time is not affected by the time of the day.

Strategies to prevent radial artery occlusion after transradial PCI.

Radial artery occlusion (RAO) is the most common structural consequence of transradial access (TRA) with an estimated incidence ranging from 2-10 %. Its occurrence is free of any major clinical consequences, especially at rest, with most if not all cases of digital ischemia occurring as a result of embolization, rather than RAO. The incidence of RAO is unacceptably high if "best practices" are not followed. Strategies to prevent RAO need to be implemented to preserve radial artery patency in order to exploit other benefits of TRA.

Preserving Radial Patency: Multiple Prior Radial Procedures and Now Large-Bore Access.

6 French percutaneous coronary intervention (PCI), has become widely adopted. We describe a case of successful 8 French transradial access (TRA) coronary intervention using state of the art hemostasis technique with preservation of radial patency after the procedure.

Effect of duration of hemostatic compression on radial artery occlusion after transradial access.

OBJECTIVES: To evaluate the effect of duration of hemostatic compression on the incidence of radial artery occlusion (RAO) after transradial coronary intervention. BACKGROUND: RAO occurs in 2-10% of patients after transradial access. The effect of duration of hemostatic compression on occurrence of RAO is unknown. METHODS: Four hundred consecutive patients undergoing transradial coronary intervention were retrospectively analyzed. Group I (n = 200) patients received hemostatic compression for 6 hr after completion of the procedure, and group II (n = 200) patients for 2 hr after completion of the procedure. TR band was used for hemostasis. Demographic and procedural variables as well as early (24 hr) and chronic (30 days) RAO as well as bleeding events were recorded. RESULTS: Demographic as well as procedural variables were similar between group I and group II. Early radial artery occlusion (ERAO) occurred in 12% of patients in group I and 5.5% of patients in group II, the difference was statistically significant (P = 0.025). Chronic radial artery occlusion (CRAO) occurred in 8.5% of patients in group I and 3.5% of patients in group II, the difference was statistically significant (P = 0.035). Occlusive compression was the only independent predictor of radial artery occlusion [Odds ratio = 13.1, P = 0.001]. Two patients in group I and one in group II developed small hematoma (P = 0.161). CONCLUSIONS: Shorter duration of hemostatic compression is associated with a lower incidence of early and chronic RAO, without increase in bleeding complications, although maintaining radial patency during hemostatic compression, eliminates the adverse effect of duration of compression.

Radial artery access technique evaluation trial: randomized comparison of Seldinger versus modified Seldinger technique for arterial access for transradial catheterization.

BACKGROUND: Radial artery access for transradial catheterization is obtained using either Seldinger or modified Seldinger technique. There is no comparative evaluation of the safety and benefits of these two techniques. METHODS: Four hundred twelve patients undergoing transradial catheterization were randomized to group I (n = 210) Seldinger technique, and group II (n = 202) modified Seldinger technique. Demographic and procedural data were collected at the time of the procedure. Data on hematoma and radial artery occlusion (RAO) were recorded at 24 hr and 30 days after the procedure. RESULTS: Age, gender, weight, height, and history of diabetes mellitus were comparable between groups I and II. Access time (78.3 ± 37.7 sec vs. 134.2 ± 87.5 sec, P < 0.001), procedure time (17.1 ± 6.4 min vs. 19.3 ± 7.1 min, P < 0.01), number of attempts to get access (1.7 ± 0.8 vs. 2.2 ± 0.8, P < 0.001), were significantly different favoring group I. Access was obtained at first attempt in 53% of patients in group I compared with 16% in group II (P < 0.001). Change in technique (crossover) was required in 10.8% of group II patients, compared with no crossover in group I (P < 0.0001). Incidence of hematoma (0.5% vs. 1.5%, P > 0.2) and 30-day RAO (4.3% vs. 3.9 %, P > 0.5) was similar between groups I and II. CONCLUSIONS: Seldinger technique is a faster and more predictable radial artery access technique compared with modified Seldinger technique with no increase in bleeding or RAO.

Simultaneous Measurement of Left Ventricular and Aortic Pressures Using a Dual-Catheter System With Single Arterial Access.

Although echocardiography remains the key tool for evaluation of aortic valve stenosis severity, in a fair minority of patients invasive evaluation is still needed. Dual-lumen catheters allow for simultaneous trans-aortic pressure measurements with single arterial access. We describe a technique where traditional hardware using non-dedicated catheters can be used to obtain simultaneous pressure measurements using a 6 French single arterial access.