Traditional Transfemoral Access Research Articles

Trans-radial cerebral angiography for stereotactic radiosurgery treatment of arteriovenous malformations

The popularity of trans-radial access (TRA) for cerebral angiography is growing. Potential benefits of TRA over traditional trans-femoral access (TFA) are multitude. This study aimed to evaluate discharge outcomes and patient opinion of TRA compared to TFA in patients undergoing cerebral angiography prior to stereotactic radiosurgery (SRS) treatment for cerebral arteriovenous malformations. Consecutive patients treated at the National Centre for Stereotactic Radiosurgery (Sheffield, United Kingdom) over a 22-month period were included. All patients underwent cerebral angiography with either TRA or TFA as part of treatment planning prior to SRS. TRA patients who had previously undergone TFA in other centres were surveyed for their experience of cerebral angiography using a questionnaire. SRS staff at our centre was approached for their opinion. 492 patients were included (median age=43 years, 57.5% male, median lesions treated=1). More patients underwent angiography with TFA (75.2%) than TRA (24.8%). No difference was found in accumulated dose for angiography between the groups (p>0.05). There was 17.6% reduction in overnight stay between TRA and TRF, the proportion of patients requiring overnight admission was higher for the TFA (35.2%) than TRA (17.6%, p<0.05). 101 patients were surveyed, with a response rate of 47%. Most respondents (79%) indicated preference for TRA over TFA. Use of TRA in pre-SRS cerebral angiography is feasible and improves both patient and staff experience. The adoption of TRA could have important implications for department resources and costs by reducing the proportion of overnight admissions.

103 A Bifurcation Model Predicts Intravascular Catheter Herniation When Using Transradial Access in Neuroendovascular Procedures

INTRODUCTION: The speed and safety of acute ischemic stroke interventions can be improved with catheter-based revascularization performed via the transradial access versus the traditional transfemoral access. A critical source of delay and procedural failure is a phenomenon known as herniation where the catheter system suddenly buckles and deviates from the intended endovascular pathway as the surgeon attempts to track one device over or through another around a tight bend. METHODS: Recent modeling work suggests that herniation is associated with a bifurcation in strain energy. We hypothesized that herniation could be predicted by modeling the strain energy stored in a catheter based on its flexural rigidity and the vascular anatomy. To test our hypothesis, we developed a computational model using finite element analysis and an experimental benchtop model using 3D-printed patient-specific aortic arches. Our mathematical model was validated in vivo using observational data derived from patient and porcine endovascular surgeries. RESULTS: Vascular geometry and flexural rigidity were used to derive the bifurcation condition and predict catheter stability versus instability (herniation). Catheter instability criterion was predictive of herniation in our computational model (sensitivity 100.0%, PPV 93.5%, NPV 100.0%); experimental ex vivo model (sensitivity 92.3%, PPV 89.6%, NPV 90.0%); patient in vivo model (sensitivity 100.0%, PPV 80.0%, NPV 100.0%); and porcine in vivo model (sensitivity 100%, PPV 100%, NPV 100%). CONCLUSIONS: We validated a predictive model of catheter herniation based upon the hypothesis that bifurcation in strain energy drive the phenomenon. Key factors in the model are the curvature of the vascular pathway and the flexural rigidity of the coaxial devices. Results suggest that strategic selection of catheters and wires based on their known flexural rigidity can be used to prevent the bifurcation in strain energy that causes herniation.

A comparison of radial versus femoral artery access for acute stroke interventions.

In this study, the authors aimed to investigate procedural and clinical outcomes between radial and femoral artery access in patients undergoing thrombectomy for acute stroke. The authors conducted a single-institution retrospective analysis of 104 patients who underwent mechanical thrombectomy, 52 via transradial access and 52 via traditional transfemoral access. They analyzed various procedural and clinical metrics between the two patient cohorts. There was no difference between patient demographics or presenting symptoms of stroke severity between patients treated via transradial or transfemoral access. The mean procedural time was similar between the two treatment cohorts: 60.35 ± 36.81 minutes for the transradial group versus 65.50 ± 29.92 minutes for the transfemoral group (p = 0.451). The mean total fluoroscopy time for the procedure was similar between the two patient cohorts (20.31 ± 11.68 for radial vs 18.49 ± 11.78 minutes for femoral, p = 0.898). The majority of patients underwent thrombolysis in cerebral infarction score 2b/3 revascularization, regardless of access site (92.3% for radial vs 94.2% for femoral, p = 0.696). There was no significant difference in the incidence of access site or periprocedural complications between the transradial and transfemoral cohorts. Acute stroke intervention performed via transradial access is feasible and effective, with no significant difference in procedural and clinical outcomes compared with traditional transfemoral access. Larger studies are required to further validate the efficacy and limitations of transradial access for neurointerventional procedures.

Comparison of Transradial vs Transfemoral Access in Neurovascular Fellowship Training: Overcoming the Learning Curve.

The transradial access (TRA) is rapidly gaining popularity for neuroendovascular procedures as there is strong evidence for its benefits compared to the traditional transfemoral access (TFA). However, the transition to TRA bears some challenges including optimization of the interventional suite set-up and workflow as well as its impact on fellowship training. To compare the learning curves of TFA and TRA for diagnostic cerebral angiograms in neuroendovascular fellowship training. We prospectively collected diagnostic angiogram procedural data on the performance of 2 neuroendovascular fellows with no prior endovascular experience who trained at our institution from July 2018 until June 2019. Metrics for operator proficiency were minutes of fluoroscopy time, procedure time, and volume of contrast used. A total of 293 diagnostic angiograms were included in the analysis. Of those, 57.7% were TRA and 42.3% were TFA. The median contrast dose was 60 cc, and the median radiation dose was 14 000 μGy. The overall complication rate was 1.4% consisting of 2 groin hematomas, 1 wrist hematoma, and 1 access-site infection using TFA. The crossover rate to TFA was 2.1%. Proficiency was achieved after 60 femoral and 95 radial cases based on fluoroscopy time, 52 femoral and 77 radial cases based on procedure time, and 53 femoral and 64 radial cases based on contrast volume. Our study demonstrates that the use of TRA can be safely incorporated into neuroendovascular training without causing an increase in complications or significantly prolonging procedure time or contrast use.

Transradial Endovascular Intervention: Results From the Radial accEss for nAvigation to Your CHosen Lesion for Peripheral Vascular Intervention (REACH PVI) Study

Background/PurposeThe transradial approach has been proposed as an alternative to traditional transfemoral access for diagnostic and therapeutic purposes in several catheterization procedures. Historically, extended length devices for lower limb endovascular interventions have been limited. The aim of this study was to investigate the acute clinical outcomes of orbital atherectomy (OA) via transradial access (TRA) for the treatment of lower extremity peripheral artery disease (PAD). Methods/materialsREACH PVI was a multicenter, prospective, observational study (NCT03943160) including subjects with PAD and target lesion morphology appropriate for OA. All patients were followed post-procedure through the first standard of care follow-up visit. ResultsA total of 50 patients were enrolled. In most cases the indication for intervention was disabling claudication (74.0%). Overall, 50 target lesions were treated, 92.0% of lesions were femoropopliteal and 8.0% were infrapopliteal. The average lesion length was 98.3 ± 87.5 mm and 78.0% of the lesions were severely calcified. Balloon angioplasty was performed in 98.0% of target lesions, while a stent was deployed in 16.0%. Treatment success was 98.0%; in only one case the result was sub-optimal (>30% stenosis with stent placement) and a significant dissection was reported. No serious distal embolization, serious thrombus formation or serious acute vessel closure were observed intra- or post-procedurally. ConclusionsTransradial OA followed by percutaneous transluminal angioplasty for lower extremity PAD is feasible and demonstrates a favorable safety profile. Extended length devices such as the Extended Length Orbital Atherectomy System could further facilitate transradial endovascular procedures by increasing its spectrum of application.

Transradial Access: A Comprehensive Review

Transradial access (TRA) via the left radial artery is an alternative to traditional transfemoral access for catheter-based procedures that is becoming increasingly more relevant in all types of arterial vascular interventions. First investigated in the realm of cardiology, TRA has been proven to provide many benefits (such as lower complication rates, lower cost, and improved patient comfort during and after the procedure) when compared with traditional femoral access while maintaining efficacy. This article provides an in-depth summary of the technical aspects of radial access while incorporating more recent data to explain patient preference for TRA, and the ways that TRA can improve peri-procedure workflow and compensation. It also describes potential complications, such as radial artery spasm, difficult anatomic variants and radial artery occlusion, and then gives techniques for mitigating and treating these complications. The article explains why TRA has become an important option for vascular and interventional radiology physicians, and why it is likely that this will continue to grow in relevance.

Transradial Approach for Aortoiliac and Femoropopliteal Interventions: A Systematic Review and Meta-analysis

Purpose: To present a systematic review and meta-analysis comparing the transradial approach for aortoiliac and femoropopliteal interventions to the traditional transfemoral access. Methods: A search of the public domain databases MEDLINE, SCOPUS, Web of Science, and Cochrane Library Databases was performed to identify studies related to the use of the transradial approach for infra-aortic procedures. Meta-analysis was used to compare the transradial to the transfemoral route in terms of procedure success, complications, procedure parameters, and hospital length of stay. Results are presented as the odds ratio (OR) and 95% confidence interval (CI). Results: Nineteen studies containing 638 patients with transradial access for lower limb interventions were selected. Lesions were treated from the aortic bifurcation down to the popliteal artery. The mean technical success rate was 90.9%, conversion to a transfemoral approach was necessary in 9.9%, and complications were reported in 1.9%. The meta-analysis included 4 comparative studies involving 114 transradial and 208 transfemoral procedures. There was no significant advantage of either approach in terms of procedure success (OR 5.0, 95% CI 0.49 to 50.83, p=0.17), but the risk of developing a complication was significantly lower (OR 0.25, 95% CI 0.07 to 0.86, p=0.03) with the transradial approach. Conclusion: Transradial access for lower limb endovascular interventions can be performed with comparable technical success and a lower overall complication profile compared to transfemoral access.

Training the next generation of invasive cardiologists: Feasibility of implementing a trans-radial access program at an academic hospital.

Slow adoption of trans-radial access (TRA) for left heart catheterization (LHC) in the U.S. may be related to concerns about procedural complexity and a steep learning curve. However, TRA acceptance among novice operators remains poorly characterized. We initiated a 1-year TRA learning period among lower-risk outpatients, followed by a "radial-first" policy for all LHC patients beginning year 2. By year 3, all fellows prospectively collected diagnostic LHC data as part of a quality improvement study. TRA procedural characteristics were compared with patients undergoing trans-femoral access for the 3months prior to the TRA program, and trends over time were evaluated. Between 7/2009 and 6/2012, we identified 960 patients undergoing LHC via TRA by 23 rotating cardiology fellows supervised by 5 interventional cardiologists. When evaluated against the 160 trans-femoral comparator patients, TRA patients had lower procedural success through the initial access site (88% vs. 99%, p<0.001) and longer fluoroscopy times (9.5 [5.8-15.9] vs. 6.5 [3.1-12.7] min, p<0.001), with similar contrast volumes and fewer catheters used. Despite tackling more complex patients during years 2-3, there were improvements in fluoroscopy times, catheter utilization, contrast volumes, and procedural success rates over time (all p<0.001). The dedicated adoption of TRA by an academic catheterization laboratory demonstrated improvements in efficiency and resource utilization over a relatively short period of time. Additional exposure to TRA during training may help facilitate acceptance of this approach among the next generation of invasive cardiologists. When initiating a trans-radial access program for cardiac catheterization at an academic training hospital, procedural success rates were lower and fluoroscopy times were higher than traditional trans-femoral access. Nonetheless, other procedural variables were similar between the 2 approaches, and improvements over time were consistent with the learning curves reported among experienced cardiologists in prior studies. Exposure to trans-radial access during training may help facilitate acceptance of this approach among the next generation of invasive cardiologists.

A systematic review of transcatheter aortic valve implantation via carotid artery access

BackgroundThe carotid artery is a novel access route for transcatheter aortic valve implantation (TAVI). This may represent a viable alternative in patients unsuitable for TAVI via traditional transfemoral access, up to 20%, as well as other access routes such as subclavian, transapical and aortic. This systematic review summarises the current evidence for its safety and feasibility. MethodsA systematic review was conducted as per the Preferred Reporting Instructions for Systematic Reviews and Meta-analysis (PRISMA) guidelines using five electronic databases. Results16 studies were identified, including three prospective cohort studies, one retrospective cohort study, three case series and eight case reports. Data on 74 patients (mean age 76.9years) was extracted including pre-operative work-up, technical procedure details and outcomes.This found 1 intraoperative death, 2 further deaths within 30days, two incidences of transient ischaemic attack, no incidences of stroke, myocardial infarction, carotid access site complications or infection, 1 patient required new dialysis and 1 patient had an intraoperative dissection which resolved. Follow-up from 30days to 1year showed symptomatic improvement and echocardiographic improvement in line with those seen in transfemoral TAVI. ConclusionsThe available data on TAVI via carotid access demonstrate technical feasibility with comparable outcomes to other traditional access routes. A low number of patients, heterogeneous clinical endpoints and relatively short follow-up periods limit formal meta-analysis and firmer conclusions. For patients in which other access routes are impossible, TAVI via carotid access represents a viable and potentially crucial alternative in patients who might otherwise be untreatable.

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

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). 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. 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. 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. None.

A review of radiation exposures associated with radial cardiac catheterisation

Transradial (TR) cardiac catheterisation is thought to be associated with an increased exposure to radiation compared with the traditional transfemoral (TF) access. This paper provides a review of current literature describing these reported associations. Although several studies have reported an increase in radiation exposure to both operator and patient with TR compared with TF access, others have reported findings suggesting no significant difference, even reporting decreased exposure with TR access. Ultimately, increased radiation exposure appears likely with TR access; however, in consideration of the many benefits associated with TR access, radiation exposure remains only one of many considerations when deciding between routes of access.