Distal Radial Artery Access in the Anatomical Snuffbox for Neurointerventions: Case Report

Transradial access for the endovascular treatment of intracranial aneurysms using the Woven EndoBridge device: A systematic review and pooled analysis

BACKGROUND

The Woven EndoBridge (WEB) device is a minimally invasive endovascular treatment option for patients with cerebral aneurysms. Transradial access (TRA) is a technique that involves accessing the arterial system through the radial artery in the wrist rather than the femoral artery in the groin. Several studies have investigated the use of TRA for WEB device deployment in treating intracranial aneurysms.

METHODS

A systematic review was conducted to evaluate the TRA for WEB device deployment in treating intracranial aneurysms. The databases PubMed, Cochrane, Embase, Scopus, and Web of Science were searched. To reduce the risk of bias, this systematic review only included studies reporting on using TRA in WEB device deployment for intracranial aneurysm treatment with a minimum of four patients.

RESULTS

In this systematic review, 186 patients were included across five studies, with TRA used in 183 cases analyzed. The study population had a higher proportion of females (n = 118%-69%) than males, with a mean age of 62 years old. Among the aneurysms treated, 46 were ruptured, and 119 were located at bifurcation sites, with a mean maximum diameter/width of 6.6 mm and mean height of 5.9 mm. Adjunctive coiling was used in three cases, and adjunctive stenting was used in nine cases. In two cases, conversion to a femoral artery access was necessary.

CONCLUSION

The available results suggest TRA with the WEB device is a safe and effective alternative. However, using TRA versus TFA should be individualized based on patient factors and operator experience.

Distal Radial Access: Is There a Clinical Benefit?

For decades, the femoral artery has been the most common vascular access for diagnostic and therapeutic endovascular procedures. However, over the past 20 years, radial access has been gaining popularity, as it is a safer and allows practical access with more benefits. Recently, the new distal radial access has proven to be an equal or perhaps even safer vascular access for diagnostic and therapeutic coronary and noncoronary interventions. Today, this access should be in the arsenal of every interventional surgeon.

Transradial Access Failures During Neuroangiography for Patients With Moyamoya

BACKGROUND

Despite studies continuing to demonstrate the utility of transradial access (TRA) in neuroangiography, minimal data exist regarding predictors of TRA failure. Furthermore, although many patients with moyamoya disease/syndrome will require life-long angiographic evaluation, even less has been reported on the usage of TRA in this population.

OBJECTIVE

To perform a matched analysis at our high-volume moyamoya center to determine predictors of TRA failure in these patients.

METHODS

A total of 636 patients undergoing TRA for neuroangiography were identified from 2018 to 2020. Demographic and angiographic characteristics including radial artery spasm (RAS), radial anomalies, and access site conversion were compared between patients with moyamoya and the rest of the cohort. A 4:1 matched analysis, based on age and sex, was also performed to eliminate confounding variables.

RESULTS

Patients with moyamoya were younger (40 vs 57 years, P < .0001), had smaller radial diameters (1.9 vs 2.6 mm, P < .0001), more commonly had a high brachial bifurcation (25.9% vs 8.5%, P = .008), more frequently experienced clinically significant RAS (40% vs 8.4%, P < .0001), and more often required access site conversion (26.7% vs 7.8%, P = .002). Increasing age was associated with less TRA failures in patients with moyamoya (odds ratio = 0.918) but more failures in the rest of the cohort (odds ratio = 1.034). In the matched analysis, patients with moyamoya continued to experience more radial anomalies, RAS, and access site conversions.

CONCLUSION

Patients with moyamoya, when controlling for age and sex, have higher rates of TRA failure during neuroangiography. Increasing age in Moyamoya is inversely correlated with TRA failures suggesting that younger patients with moyamoya are at higher risk of extracranial arteriopathy.

Patient and procedure selection for mechanical thrombectomy: Toward personalized medicine and the role of artificial intelligence

Mechanical thrombectomy (MT) for ischemic stroke due to large vessel occlusion is standard of care. Evidence-based guidelines on eligibility for MT have been outlined and evidence to extend the treatment benefit to more patients, particularly those at the extreme ends of a stroke clinical severity spectrum, is currently awaited. As patient selection continues to be explored, there is growing focus on procedure selection including the tools and techniques of thrombectomy and associated outcomes. Artificial intelligence (AI) has been instrumental in the area of patient selection for MT with a role in diagnosis and delivery of acute stroke care. Machine learning algorithms have been developed to detect cerebral ischemia and early infarct core, presence of large vessel occlusion, and perfusion deficit in acute ischemic stroke. Several available deep learning AI applications provide ready visualization and interpretation of cervical and cerebral arteries. Further enhancement of AI techniques to potentially include automated vessel probe tools in suspected large vessel occlusions is proposed. Value of AI may be extended to assist in procedure selection including both the tools and technique of thrombectomy. Delivering personalized medicine is the wave of the future and tailoring the MT treatment to a stroke patient is in line with this trend.

Distal radial artery access in noncoronary procedures

Since the beginning of interventional cardiology and for decades, the femoral artery has been the access of choice for both diagnostic and interventional endovascular procedures. Due to an extensive evidence base accumulated over the last 20 years, the majority of interventional cardiologists around the world prefer classical radial artery access for both elective and emergency procedures. A similar trend has been observed for distal radial artery access over the last five years. Noncoronary endovascular surgery undergoes the same stages of improvement and optimization of access, but in a more accelerated way. The goal of this review is to analyze the literature on distal radial artery access in noncoronary procedures.

Radial Long Sheath Angioplasty for Proximal Severe Flow Limiting Radial Artery Spasm Utilizing the Dotter Technique

BACKGROUND

Although studies continue to demonstrate the advantages of transradial access (TRA) for neurointerventions, radial artery spasm (RAS) remains a frequent cause of TRA failure. Dotter initially described a technique to dilate areas of peripheral vascular stenosis by advancing sequentially larger catheters across the lesion over a wire. We present our institutional experience performing a modified Dotter technique utilizing long radial sheaths to dilate areas of proximal flow limiting RAS.

OBJECTIVE

To review the use of the Dotter technique for alleviating RAS in patients undergoing TRA for neurointerventions.

METHODS

A retrospective review of all patients undergoing TRA for neurointerventions at our institution from 2018-2020 was performed to identify patients with proximal flow limiting RAS. In identified patients, a modified Dotter technique was employed to dilate the stenosis. Demographic and periprocedural data were assessed to identify any adverse outcomes.

RESULTS

Four patients with severe proximal flow limiting RAS were identified. In each case, a hydrophilic long radial sheath and vascular dilator were sequentially advanced through the stenosis. In all cases, repeat angiography demonstrated improvement of the spasm and final radial angiograms demonstrated persistent improvement in caliber and regularity of the vessel. Each procedure was also completed via TRA with no periprocedural complications.

CONCLUSIONS

Our modified Dotter technique is effective in bypassing areas of severe proximal flow limiting RAS thus obviating the need for access site conversion. Additional studies are warranted to understand the implication of the angioplasty-like effects seen within the radial artery following removal of the long radial sheaths.

Access Route for Endovascular Neurointervention - Transfemoral to Transradial: Is it Worth the Effort and are we Ready for the Change?

Transfemoral access for neurointerventions has been a time-tested technique of entering the vascular network of the body and reaching the intended targets. However, it has its own share of shortcomings in the form of long admission times leading to increased costs, patient inconvenience and local (though infrequent) adverse affects. Transradial route has taken the interventional cardiology domain by storm and is staring now at other vascular domains especially neurointervention. It has shown better outcomes than the transfemoral route in many aspects. The current article discusses the vascular access perspectives with an exhaustive overview of the transradial route concerning its historical perspectives, its requirement in the current clinical scenario, the procedure per se including the adverse effects and whether it has the real world charm to displace the transfemoral route into the backseat. Transradial access in neurointervention is here to stay, however it would require training, certain modifications in the standard catheters that one currently uses for cerebral procedures and constant practice by the operator to cross the learning curve and attain a certain level of competence before he becomes comfortable with the technique.

Initial experience of subcutaneous nitroglycerin for distal transradial access in neurointerventions

BACKGROUND

Transradial access (TRA) for diagnostic and interventional neuroendovascular procedures has gained significant popularity in recent years due to its improved safety profile and appeal to patients compared with transfemoral access. However, risks of TRA include hand ischemia in cases of poor ulnar collateral circulation and inability to cannulate the radial artery due to its relatively small diameter. By accessing the radial artery distal to the superficial palmar arch where ulnar collateral blood flow arises, in the anatomic snuffbox, the risk of hand ischemia is theoretically eliminated. The use of subcutaneous nitroglycerin and lidocaine to improve rates of success in radial artery access has been reported in the cardiac literature, however, has yet to be described for neurointerventional procedures. We discuss our technique and report our initial experience using subcutaneous nitroglycerin and lidocaine cocktail for access to the distal transradial artery in a variety of neuroendovascular procedures.

METHODS

A retrospective review of our institution's database of neurointerventional and diagnostic procedures performed using dTRA was conducted, and 64 patients were identified between February and December 2020. Patient demographics, clinical data, procedural details, and radiographic information were collected and analyzed.

RESULTS

A total of 64 patients underwent neurointerventional procedures using the subcutaneous injection for dTRA access. The procedures performed included diagnostic cerebral angiograms (n = 47), stent and balloon assisted aneurysm coiling (n = 5), flow diversion (n = 2), intra-saccular device placement (n = 1), mechanical thrombectomy (n = 1), tumor embolization (n = 1), middle meningeal artery embolization (n = 2), extracranial carotid stent placement (n = 2), and arteriovenous malformation embolization (n = 3). While no complications of hand ischemia were appreciated, the access site conversion rate was 3.1%; 2 cases required a switch to femoral artery access due to proximal vessel tortuosity and aortic anatomical variations, and not due to access site complication. Furthermore, on repeat angiograms by the same proceduralist, distal TRA (dTRA) was successful in 100% of the cases.

CONCLUSION

dTRA using subcutaneous nitroglycerin and lidocaine is a safe and effective method for neurointerventional and diagnostic procedures.

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.

The Rist radial access system: a multicenter study of 152 patients

BACKGROUND

Transradial access (TRA) for neurointervention is becoming increasingly popular as experience with the technique grows. Despite reasonable efficacy using femoral catheters off-label, conversion to femoral access occurs in approximately 8.6-10.3% of TRA cases, due to an inability of the catheter to track into the vessel of interest, lack of support, or radial artery spasm.

METHODS

This is a multicenter, retrospective case series of patients undergoing neurointerventions using the Rist Radial Access System. We also present our institutional protocol for using the system.

RESULTS

152 patients were included in the cohort. The most common procedure was flow diversion (28.3%). The smallest radial diameter utilized was 1.9 mm, and 44.1% were performed without an intermediate catheter. A majority of cases (96.1%) were completed successfully; 3 (1.9%) required conversion to a different radial catheter, 2 (1.3%) required conversion to femoral access, and 1 (0.7%) was aborted. There was 1 (0.7%) minor access site complication and 4 (2.6%) neurological complications.

CONCLUSIONS

The Rist catheter is a safe and effective tool for a wide range of complex neurointerventions, with lower conversion rates than classically reported.

Lessons Learned After 760 Neurointerventions via the Upper Extremity Vasculature: Pearls and Pitfalls

BACKGROUND

The radial approach has been gaining more widespread use by neurointerventionalists fueled by data from the cardiology literature showing better safety and overall reduced morbidity.

OBJECTIVE

To present our institution's experience with the radial approach for neuroendovascular interventions in 614 consecutive patients who underwent a cumulative of 760 procedures.

METHODS

A retrospective analysis was performed and identified neuroendovascular procedures performed via the upper extremity vasculature access site.

RESULTS

Amongst 760 procedures, 34.2% (260) were therapeutic, and 65.7% (500) were nontherapeutic angiograms. Access sites were 71.5% (544) via a conventional radial artery, 27.8% (211) via a distal radial artery, 0.5% (4) via an ulnar artery, and 0.1% (1) via the brachial artery. Most of the procedures (96.9%) were performed via the right-sided (737), 2.9% (22) via the left-sided, and 0.1% (1) via a bilateral approach. Major access site complications occurred at a rate of 0.9% (7). The rate of transfemoral conversion was 4.7% (36). There was a statistically higher incidence of transfemoral conversion when repeat procedures were performed using the same access site. Also, there was no significant difference between nontherapeutic procedures performed using the right and left radial access, and conventional versus distal radial access. Procedural metrics improved after completion of 14 procedures, indicating a learning curve that should be surpassed by operators to reach optimal outcomes.

CONCLUSION

Radial artery catheterization is a safe and effective means of carrying out a wide range of neuroendovascular procedures associated with excellent clinical outcomes and an overall low rate of periprocedural complications.

Dual-center study comparing transradial and transfemoral approaches for flow diversion treatment of intracranial aneurysms

BACKGROUND

The transfemoral approach (TFA) has been the traditional approach for neurointerventional cases. While the TFA allows for triaxial support in flow diverting stent cases, it is associated with access site complications. Recently, the transradial approach (TRA) has emerged as a safer alternative to the TFA. To the best of our knowledge, there have only been single-center studies comparing outcomes in flow diverter cases for these approaches. We demonstrate the safety and feasibility of the TRA for placement of flow diverting stents in the treatment of unruptured intracranial aneurysms at two high-volume centers.

MATERIALS AND METHODS

We performed a retrospective review of prospectively collected institutional databases at two high-volume neuroendovascular centers. Cases from 2016 to 2018 of unruptured intracranial aneurysms treated by flow diverting stenting accessed through either the TRA or the TFA were compared. Patient demographics, procedural and radiographic metrics including location and size of the aneurysm, size, and length of the flow diverter implant, and fluoroscopic time were recorded. Puncture site complications and length of hospital stay were also included in the data analysis.

RESULTS

There were three out of 29 TRA cases which were converted to the TFA. None of the TRA patients experienced site complications, whereas three TFA patients experienced site complications. While TRA and TFA patients did not differ significantly in their exposure to radiation, TRA patients experienced shorter hospital stays.

CONCLUSIONS

While long-term studies are still lacking regarding this approach, we demonstrate that the TRA is a safe and feasible approach for flow diverter stent placement.

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.

Distal Transradial Access for Diagnostic Cerebral Angiography and Neurointervention: Systematic Review and Meta-analysis

BACKGROUND

Radial artery access for cerebral angiography is traditionally performed in the wrist. Distal transradial access in the anatomic snuffbox is an alternative with several advantages.

PURPOSE

Our aim was to review the safety and efficacy of distal transradial access for diagnostic cerebral angiography and neurointerventions.

DATA SOURCES

We performed a comprehensive search of the literature using PubMed, Scopus, and EMBASE.

STUDY SELECTION

The study included all case series of at least 10 patients describing outcomes associated with distal transradial access for diagnostic cerebral angiography or a neurointervention.

DATA ANALYSIS

Random-effects models were used to obtain pooled rates of procedural success and complications.

DATA SYNTHESIS

A total of 7 studies comprising 348 (75.8%) diagnostic cerebral angiograms and 111 (24.2%) interventions met the inclusion criteria. The pooled success rate was 95% (95% CI, 91%-98%; I² = 74.33). The pooled minor complication rate was 2% (95% CI, 1%-4%; I² = 0. No major complications were reported. For diagnostic procedures, the combined mean fluoroscopy time was 13.53 [SD, 8.82] minutes and the mean contrast dose was 74.9 [SD, 35.6] mL.

LIMITATIONS

A small number of studies met the inclusion criteria, all of them were retrospective, and none compared outcomes with proximal transradial or femoral access.

CONCLUSIONS

Early experience with distal transradial access suggests that it is a safe and effective alternative to proximal radial and femoral access for performing diagnostic cerebral angiography and interventions. Additional studies are needed to establish its efficacy and compare it with other access sites.

Upper extremity transvenous access for neuroendovascular procedures: an international multicenter case series

BACKGROUND

Radial artery access for transarterial procedures has gained recent traction in neurointerventional due to decreased patient morbidity, technical feasibility, and improved patient satisfaction. Upper extremity transvenous access (UETV) has recently emerged as an alternative strategy for the neurointerventionalist, but data are limited. Our objective was to quantify the use of UETV access in neurointerventions and to measure failure and complication rates.

METHODS

An international multicenter retrospective review of medical records for patients undergoing UETV neurointerventions or diagnostic procedures was performed. We also present our institutional protocol for obtaining UETV and review the existing literature.

RESULTS

One hundred and thirteen patients underwent a total of 147 attempted UETV procedures at 13 centers. The most common site of entry was the right basilic vein. There were 21 repeat puncture events into the same vein following the primary diagnostic procedure for secondary interventional procedures without difficulty. There were two minor complications (1.4%) and five failures (ie, conversion to femoral vein access) (3.4%).

CONCLUSIONS

UETV is safe and technically feasible for diagnostic and neurointerventional procedures. Further studies are needed to determine the benefit over alternative venous access sites and the effect on patient satisfaction.

Navigating radial artery loops in neurointerventions

BACKGROUND

Although studies continue to demonstrate lower complications in neurointerventions using transradial access (TRA) compared with transfemoral approaches, anatomic radial variants can be difficult to navigate and remain one of the frequent causes of access site conversion.

OBJECTIVE

To evaluate predictors of TRA failure in neuroendovascular patients with radial loops and suggest a protocol for managing these anomalies.

METHODS

A prospective collection of patients undergoing TRA at participating institutions from July 2018 to September 2020 was reviewed. Patients with a radial loop were identified. Patient demographics and procedural characteristics were evaluated to determine predictors of both TRA failure and successful reduction of the radial loop.

RESULTS

We identified 32 transradial neurointerventions in which patients had radial loops. Twenty-two (68.8%) were identified by diagnostic angiography, and the majority were performed for evaluation or treatment of an aneurysm (56.3%). TRA failure occurred in 13 (40.6%) of the cohort and happened more frequently in patients over 60 years of age (p=0.01) and those with recurrent radial artery diameters ≤2 mm (p=0.02). Of the 19 patients who had successful TRA, 12 (63.2%) procedures were performed through the recurrent radial artery.

CONCLUSION

Although radial loops are associated with high transradial failure rates, our results suggest that the presence of a loop is not an absolute contraindication to TRA. Therefore, we recommend attempting loop navigation using our protocol. Patient age, vascular tortuosity, and recurrent radial artery size should help dictate when to convert to an alternative access site.

Safety and feasibility of the distal transradial approach: A novel technique for diagnostic cerebral angiography

PURPOSE

We aimed to evaluate the safety and feasibility of the distal transradial approach (DTRA) as a novel technique for cerebral angiography based on our institutional initial experience.

METHODS

We retrospectively analyzed our institutional database of consecutive diagnostic cerebral angiographies performed with DTRA from December 2018 to August 2019. Patient demographics and clinical and procedural data were recorded.

RESULTS

In total, 51 diagnostic cerebral angiographies in 51 patients (age, 15-83 years; mean age, 59.4 years, SD 13.5; 35 (69%) females) were performed or attempted with DTRA. Ultrasound evaluation showed that the mean inner distal radial artery diameter was significantly smaller than the mean inner forearm radial artery diameter (2.19 mm vs. 2.56 mm, P < 0.001). Cannulation via the distal radial artery was successful in 47 (92%) procedures. In the four procedures that failed, operators converted to the ipsilateral transradial approach without repositioning or redraping. Selective catheterization of the intended vessel was achieved in 64 (91%) of 70 vessels. In the remaining six, operators achieved the objective of the examination with angiography injecting from proximal and conversion to another approach was not required. One patient experienced temporary numbness around the puncture site after the procedure. No radial artery occlusion was identified in the patients who underwent ultrasound evaluation.

CONCLUSION

Our results demonstrate that DTRA could become a standard approach for diagnostic cerebral angiography owing to the low complication rate and the high cannulation success rate.

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

OBJECTIVE

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Trans-Radial Approach: technical and clinical outcomes in neurovascular procedures

Background

To evaluate efficacy and safety of Trans-Radial Approach (TRA) in cerebral angiography for diagnostic and therapeutic purpose.

Methods

We retrospectively included consecutive patients eligible for TRA cerebral angiography at our Institution between September 2019 and January 2020. Cerebral DSA was classified in diagnostic (one-vessel imaging) or therapeutic (emergency/elective). Technical and clinical outcome were recorded for each group.

Results

A total of 61 TRA angiographies were evaluated. Right-sided TRA was obtained in 85,2% of all cases. Interventional procedures included 11 strokes, 2 ruptured aneurysms, 2 unrupted aneurysms, 1 DAVF and 3 symptomatic atheromatous intracranial stenosis. Successful TRA angiographies were obtained in 97,6% and 94,7% for diagnostic and therapeutic group, respectively. No major radial artery complications were recorded. Mean puncture-to-final angiogram was 11 and 62 min for diagnostic and therapeutic groups, respectively. Mean radial compression maintenance was 4 h, allowing patients discharge within 6 h in all cases undergone diagnostic angiography.

Conclusions

TRA could be a valid technique in terms of efficacy and safety both for diagnostic and therapeutic cerebral angiographies, with low complication rate.

Distal Transradial Access for Coronary Angiography and Interventions

Coronary angiography is one of the most common procedures done in the United States and in other developed countries. For decades, the femoral artery has been the most common vascular access site utilized for this procedure. However, the radial access has been gaining popularity for being a safer and yet practical vascular access with substantial benefits. More recently, the novel distal transradial approach has proven to be an equally or perhaps safer vascular access for diagnostic and interventional coronary and noncoronary procedures. This technique should be in every interventional cardiologist's arsenal.

Distal radial artery (snuffbox) access for carotid artery stenting - Technical pearls and procedural set-up

PURPOSE

To report use of distal radial artery (dRA) access for carotid artery stenting (CAS) and to discuss procedural setup and technical considerations for a successful intervention.

METHODS

A retrospective review of our prospective neurointerventional database of CAS was conducted between May 2019 and March 2020. All CAS cases via dRA in the anatomical snuffbox were identified. Patient demographics, clinical information, procedural and radiographic data was collected.

RESULTS

22 CAS procedures in 20 patients via dRA were identified. Patients' mean age was 69.4 years (range 53-87 years). 3 patients were female. Mean radial artery diameter was 2.1 mm (range 1.6-2.8 mm). dRA access was achieved in all cases. Conversion to femoral access was required in 2 cases (9.1%) due to persistent radial artery vasospasm resulting in patient discomfort despite multiple additional doses of intraarterial vasodilators and added intravenous sedation as well as tortuous vessel anatomy and limited support of the catheters in a type 3 aortic arch for left CAS.

CONCLUSION

Our preliminary experience with dRA access for CAS suggests this approach to be feasible and safe for patients. Technical considerations are important and preprocedural planning is necessary for a successful intervention. Catheter systems and devices specifically designed for radial access are needed to enable more interventionalists to safely perform neurointerventional procedures via wrist access.

Distal radial artery (snuffbox) access for carotid artery stenting - Technical pearls and procedural set-up

PURPOSE

To report use of distal radial artery (dRA) access for carotid artery stenting (CAS) and to discuss procedural setup and technical considerations for a successful intervention.

METHODS

A retrospective review of our prospective neurointerventional database of CAS was conducted between May 2019 and March 2020. All CAS cases via dRA in the anatomical snuffbox were identified. Patient demographics, clinical information, procedural and radiographic data was collected.

RESULTS

22 CAS procedures in 20 patients via dRA were identified. Patients' mean age was 69.4 years (range 53-87 years). 3 patients were female. Mean radial artery diameter was 2.1 mm (range 1.6-2.8 mm). dRA access was achieved in all cases. Conversion to femoral access was required in 2 cases (9.1%) due to persistent radial artery vasospasm resulting in patient discomfort despite multiple additional doses of intraarterial vasodilators and added intravenous sedation as well as tortuous vessel anatomy and limited support of the catheters in a type 3 aortic arch for left CAS.

CONCLUSION

Our preliminary experience with dRA access for CAS suggests this approach to be feasible and safe for patients. Technical considerations are important and preprocedural planning is necessary for a successful intervention. Catheter systems and devices specifically designed for radial access are needed to enable more interventionalists to safely perform neurointerventional procedures via wrist access.

Implementation of a radial long sheath protocol for radial artery spasm reduces access site conversions in neurointerventions

BACKGROUND

Many neurointerventionalists have transitioned to transradial access (TRA) as the preferred approach for neurointerventions as studies continue to demonstrate fewer access site complications than transfemoral access. However, radial artery spasm (RAS) remains one of the most commonly cited reasons for access site conversions. We discuss the benefits, techniques, and indications for using the long radial sheath in RAS and present our experience after implementing a protocol for routine use.

METHODS

A retrospective review of all patients undergoing neurointerventions via TRA at our institution from July 2018 to April 2020 was performed. In November 2019, we implemented a long radial sheath protocol to address RAS. Patient demographics, RAS rates, radial artery diameter, and access site conversions were compared before and after the introduction of the protocol.

RESULTS

747 diagnostic cerebral angiograms and neurointerventional procedures in which TRA was attempted as the primary access site were identified; 247 were performed after the introduction of the long radial sheath protocol. No significant differences in age, gender, procedure type, sheath sizes, and radial artery diameter were seen between the two cohorts. Radial anomalies and small radial diameters were more frequently seen in patients with RAS. Patients with clinically significant RAS more often required access site conversion (p<0.0001), and in our multivariable model use of the long sheath was the only covariate protective against radial failure (OR 0.061, 95% CI 0.007 to 0.517; p=0.0103).

CONCLUSION

In our experience, we have found that the use of long radial sheaths significantly reduces the need for access site conversions in patients with RAS during cerebral angiography and neurointerventions.

Clinical experience with distal transradial access for endovascular treatment of various noncoronary interventions in a multicenter study

Background

Transradial access is a well-known alternative to conventional transfemoral access for interventional procedures. Recently, transradial access through the “snuffbox”, which lies in the radial dorsal aspect of the hand, has been introduced as a new technique with positional versatility. In this study, we aimed to evaluate the clinical feasibility and safety of distal transradial access for interventional procedures in a retrospective, multicenter study.

Material & methods

Distal transradial access was attempted in 46 patients (36 men and 10 women; mean age, 64 years) who underwent 47 consecutive procedures from January 2018 to December 2019. Procedures included chemoembolization (19/47, 40.4%), bronchial artery embolization (7/47, 14.9%), renal intervention (3/47, 6.4%), arteriovenous fistula angioplasty (7/47, 14.9%), subclavian artery stenting (5/47, 10.6%), other embolization (5/47, 10.6%), and uterine artery embolization (1/47, 2.1%). We recorded the success rate of the procedures, complications, and postprocedural hemostasis time during the follow-up period.

Results

The technical success of distal transradial access without major complications was 97.9% (46/47). Of the 46 patients, one patient (2.2%) had a minor complication, which was a thrombotic segmental occlusion of the distal radial artery. Of the enrolled patients, only one patient did not complete the transradial access procedure via the snuffbox because the left proximal subclavian artery was occluded and a crossover to conventional transfemoral access was performed. The mean postprocedural hemostasis time was 131.7 minutes (range, 120–360 minutes).

Conclusion

Distal transradial access can be a valid option for the endovascular treatment of various noncoronary interventions with technical feasibility and safety.

Predicting the degree of difficulty of the trans-radial approach in cerebral angiography

BACKGROUND

To evaluate anatomical and clinical factors that make trans-radial cerebral angiography more difficult.

METHODS

A total of 52 trans-radial diagnostic angiograms were evaluated in a tertiary care stroke center from December 2019 until March 2020. We analyzed a number of anatomical variables to evaluate for correlation to outcome measures of angiography difficulty.

RESULTS

The presence of a proximal radial loop had a higher conversion to femoral access (p<0.03). The presence of a large diameter aortic arch (p<0.01), double subclavian innominate curve (p<0.01), left proximal common carotid artery (CCA) loop (p<0.001), acute subclavian vertebral angle (p<0.01), and absence of bovine aortic arch anatomy (p=0.03) were associated with more difficult trans-radial cerebral angiography and increased fluoroscopy time-per-vessel.

CONCLUSION

The presence of a proximal radial loop, large diameter aortic arch, double subclavian innominate curve, proximal left CCA loop, acute subclavian vertebral angle, and absence of bovine aortic arch anatomy were associated with more difficult trans-radial cerebral angiography. We also introduce a novel grading scale for diagnostic trans-radial angiography.

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.

Access Through the Anatomical Snuffbox for Neuroendovascular Procedures: A Single Institution Series

BACKGROUND

Distal transradial catheterization in the anatomic snuffbox is an alternate route of access that has started to gain consideration for neuroendovascular procedures.

OBJECTIVE

To assess the feasibility and outcomes and present our institution's experience in performing neuroendovascular procedures via distal transradial access (dTRA).

METHODS

We conducted a retrospective analysis and identified 120 patients who underwent consecutive neuroendovascular procedures via dTRA in the anatomic snuffbox. Data collection was performed on indication for procedure, sheath size, number of vessels selectively catheterized, fluoroscopy time, procedure duration, radiation exposure, conversion to femoral approach, access site complication, and procedure success.

RESULTS

Of 120 patients with an average age of 54.7 yr ± 14.7, 73 (60.8%) underwent diagnostic angiograms, 38 (31.7%) underwent follow-up angiograms, and 9 (7.5%) underwent therapeutic procedures. The overall mean number of vessels catheterized was 2.5 ± 0.1 per procedure, the mean procedure time was 68.3 min ± 43.4, the mean fluoroscopy time was 10.8 min ± 7.6, the mean contrast dose was 70.6 mL ± 39.1, and the mean radiation exposure was 27 672.2 mGycm2 ± 42 728.4. Successfully completed therapeutic procedures included aneurysm 1 (0.8%), arteriovenous malformation (AVM)/arteriovenous fistula/carotid cavernous fistula 7 (5.8%), and 1 (0.8%) other treatment. Three patients (2.5%) required adjunct transfemoral endovenous access for AVM embolization. Two minor complications (1.67%) were a local wrist hematoma and a radial artery vasospasm without any sequelae.

CONCLUSION

Distal radial artery catheterization in the anatomic snuffbox is a safe and effective access site to perform neuroendovascular procedures. Complications and conversion rate are low making it a safe alternative.

Distal transradial access in the anatomical snuffbox for balloon guide-assisted stentriever mechanical thrombectomy: Technical note and case report

Recent trends in neuroendovascular surgery have seen a rise in alternative access utilization. Social media feeds such as #RadialFirst or #RadialForNeuro are the beacons of a growing movement among more and more endovascular neurosurgeons, as they venture away from the traditional femoral access gravitating toward radial access. We have previously shown our distal radial access technique utilizing the snuffbox to be a reliable means of endovascular access and in addition to traditional ventral radial access provides access to the entire cerebrum. Stroke thrombectomy often encounters reticence from those who prefer transfemoral access over the radial access. Thrombectomy has been performed radially in a few series and only once previously in a case report of distal radial access for thrombectomy. Hesitance to adopt radial access for mechanical thrombectomy is often related to perceived increased access times and a lack of suitable balloon guide catheters for radial techniques. Here, we present one of the first descriptions of a distal transradial access with balloon guide flow arrest for stentriever thrombectomy.

First case series of the transradial approach for neurointerventional procedures in pediatric patients

OBJECTIVE

The transradial approach (TRA) has been widely adopted by interventional cardiologists but is only now being accepted by neurointerventionalists. The benefits of the TRA over the traditional transfemoral approach (TFA) include reduced risk of adverse clinical events and faster recovery. The authors assessed the safety and feasibility of the TRA for neurointerventional cases in the pediatric population.

METHODS

Pediatric patients undergoing cerebrovascular interventions since implementation of the TRA at the authors' institution were retrospectively reviewed. Pertinent patient information, procedure indications, vessels catheterized, fluoroscopy time, and complications were reviewed.

RESULTS

There were 4 patients in this case series, and their ages ranged from 13 to 15 years. Each patient tolerated the procedure performed using the TRA without any postprocedural issues, and only 1 patient experienced radial artery spasm, which resolved with the administration of intraarterial verapamil. None of the patients required conversion to the TFA.

CONCLUSIONS

The TRA can be considered a safe alternative to the TFA for neurointerventional procedures in the pediatric population and provides potential advantages. However, as pediatric patients require special consideration due to their smaller-caliber arteries, routine use of ultrasound guidance is advised when attempting the TRA.

Transradial versus transfemoral approaches for diagnostic cerebral angiography: a prospective, single-center, non-inferiority comparative effectiveness study

Background

Interventional cardiology produced level 1 evidence recommending radial artery-first for coronary angiography given lower vascular complications. Neuroendovascular surgeons have not widely adopted the transradial approach. This prospective, single center, non-inferiority comparative effectiveness study aims to compare the transradial and transfemoral approaches for diagnostic cerebral angiography with respect to efficacy, safety and patient satisfaction.

Methods

Consecutive patients presenting for diagnostic cerebral angiography were selected to undergo right radial or femoral access based on date of presentation. Primary outcome was ability to answer the predefined diagnostic goal of the cerebral angiogram using the initial access site and was assessed with a non-inferiority design. Secondary outcomes included technical success per vessel, complications, procedure times and patient satisfaction.

Results

A total of 312 patients were enrolled, 158 and 154 for right radial and femoral access, respectively. The diagnostic goal of the angiogram was achieved in 152 of 154 (99%) patients who underwent attempted femoral access compared with 153 of 158 (97%) patients who underwent radial access, confirming non-inferiority of the transradial approach. Secondary outcomes showed equivalent technical success by vessel, no major complications, and similar frequency of minor complications between the two approaches. In-room time was similar between approaches, though post-procedure recovery room time was significantly shorter for transradial patients. Patient satisfaction results significantly favored the radial approach.

Conclusions

In patients undergoing diagnostic cerebral angiography, transfemoral and transradial access achieve procedural goals with similar effectiveness and safety, though patients strongly prefer the radial approach. Findings support consideration of adopting a radial-first strategy for diagnostic cerebral angiography.

Distal radial access in the anatomical snuffbox for neurointerventions: a feasibility, safety, and proof-of-concept study

PURPOSE

To report the first use of distal radial artery (dRA) access for a variety of neurointerventions and to demonstrate the safety and feasibility of this approach.

METHODS

A retrospective review of our prospective neurointerventional database of endovascular interventions was conducted and, between May and October 2019, all patients in whom the intervention was performed via dRA in the anatomical snuffbox were identified. Patient demographics, clinical information, procedural and radiographic data were collected.

RESULTS

48 patients with a mean age of 64.4 years (range 35-84 years) were included. 27 patients were female. dRA access was achieved in all cases. Conversion to femoral access was required in five cases (10.4%) due to tortuous vessel anatomy and limited support of the catheters in the aortic arch. Interventions performed included aneurysm treatment (with flow diverters, Woven EndoBridge device placement, coiling or stent-assisted coiling), arteriovenous malformation and dural arteriovenous fistula embolization, carotid artery stentings, stroke thrombectomy, thrombolysis for central retinal artery occlusion, intracranial stenting, middle meningeal artery embolization, vasospasm treatment, and spinal angiography with embolization. Radial artery vasospasm was seen in two cases and successfully treated with antispasmolytic medication. No symptomatic radial artery occlusion or ischemic event was observed.

CONCLUSION

dRA access is safe and effective for a variety of neurointerventions. Our preliminary experience with this approach is very promising and shows high patient satisfaction.

Complications of femoral versus radial access in neuroendovascular procedures with propensity adjustment

BACKGROUND

The transradial artery (TRA) approach for neuroendovascular procedures continues to gain popularity, but neurointerventionalists still lag behind interventional cardiologists in the adoption of a TRA-first approach. This study compares the complications and efficiency of the TRA approach to the standard transfemoral artery (TFA) approach at our institution during our initial phase of adopting a TRA-first approach.

METHODS

A retrospective analysis was performed on all consecutive neuroangiographic procedures performed at a large cerebrovascular center from October 1, 2018 to June 30, 2019. The standard TFA approach was compared with TRA access, with the primary outcome of complications analyzed via a propensity-adjusted analysis.

RESULTS

A total of 1050 consecutive procedures were performed on 877 patients during this 9-month period; 206 (20%) procedures were performed via TRA and 844 (80%) via TFA. The overall complication rate was significantly higher with the TFA procedures than with the TRA procedures (7% (60/844) vs 2% (4/206), respectively; p=0.003). A propensity-adjusted analysis showed that the TFA approach was a significant risk factor for a complication (OR 3.6, 95% CI 1.3 to 10.2, p=0.01). However, the propensity analysis showed that fluoroscopy times were on average 4 min less for TFA procedures than for TRA procedures (p=0.003).

CONCLUSION

The TRA approach for neuroendovascular procedures appears to be safer than the TFA approach. Although a steep learning curve is initially encountered when adopting the TRA approach, the transition to a TRA-first practice can be performed safely for neurointerventional procedures and may reduce complications.

Transarterial and transvenous access for neurointerventional surgery: report of the SNIS Standards and Guidelines Committee

The purpose of this publication is to provide a comprehensive review on the techniques and tools used for vascular access in neurointerventional procedures. Using published literature, we reviewed data on access methods, sites, tools, and techniques for neurointerventions. Recommendations are provided based on quality of data/levels of evidence and, where appropriate, expert consensus. While tools and techniques continue to be developed, current literature and experience supports certain principles regarding vascular access for neurointerventional procedures.

Distal Transradial Access in the Anatomic Snuffbox for Diagnostic Cerebral Angiography

The aim of this study was to describe the feasibility, technique, and safety of distal transradial access in the anatomic snuffbox for diagnostic cerebral angiography. A retrospective review of diagnostic cerebral angiograms obtained during a 6-month period with distal transradial access was performed. Thirty-four successful procedures were performed via distal transradial access. There were 4 failed attempts. This single-center experience using distal transradial access suggests that this technique is safe and effective.

Placement of the Woven EndoBridge (WEB) device via distal transradial access in the anatomical snuffbox: A technical note

The distal transradial access in the anatomical snuffbox for neurovascular procedures is a modification of the radial access with an improved safety profile and patient comfort compared to the conventional transradial access. However, its use has been limited to diagnostic cerebral angiography, but not aneurysm treatment. We present the first case of a 53-year-old female whose work-up for headaches showed an anterior communicating artery aneurysm. The patient underwent distal transradial cerebral angiography and subsequent placement of a Woven EndoBridge (WEB) device for treatment of the aneurysm through the same access site. The procedure was uneventful and the patient was discharged home neurologically intact. Her hand remained warm, well-perfused, and with no visible or palpable hematoma. Our report illustrates the feasibility of the distal TRA for the treatment of cerebral aneurysms using the WEB device. Further studies are necessary to confirm the additional benefits of the distal TRA over TRA for neurovascular access.

Transradial access for neurointerventions: management of access challenges and complications

Background

Numerous large randomized trials have shown a significant morbidity and mortality benefit with the transradial approach (TRA) over the transfemoral approach (TFA) for endovascular procedures. However, this technique is routinely avoided or aborted due to unfamiliarity with the technique and the associated anatomical difficulties that may be faced in this approach. The objective of this review is to identify both the common and uncommon challenges that may be encountered during a transradial approach for cerebrovascular catheterization and to provide tips and tricks to overcome the transradial learning curve.

Method

A careful review of the literature and of all our transradial cases was carried out to identify the common challenges and complications that are encountered when using TRA for diagnostic cerebral angiography and neurointerventions.

Results

A stepwise approach is provided to prevent and manage common challenges including radial artery access failure, radial artery spasm, radial artery anomalies and tortuosity, radial artery occlusion, radial artery perforation and hematoma, subclavian tortuosity and anomalies, and catheter knots and kinks.

Conclusion

The ability to recognize and navigate anatomical variations and complications unique to TRA will accelerate learning, decrease unnecessary morbidity and mortality, and further advance the neurovascular field.

Distal transradial access in the anatomical snuffbox for diagnostic cerebral angiography

BACKGROUND

The transradial approach for endovascular angiography and interventional procedures is superior to the traditional transfemoral approach in several metrics, including lower access-site complication rates, higher patient satisfaction, and lower hospital costs. Interventional cardiologists have begun to adopt the distal transradial approach (dTRA) for coronary interventions as it has an improved safety profile and improved procedural ergonomics. Adaptation of dTRA for neuroendovascular procedures promises similar benefit, but requires a learning curve.

OBJECTIVE

To report the first use of dTRA for diagnostic cerebral angiography and demonstrate the feasibility and safety of a dTRA.

METHODS

A retrospective review of our prospective institutional database of consecutive cases of cerebral DSA performed via dTRA between August 2018 and December 2018 was performed. Patient demographics, procedural and radiographic metrics, and clinical data were recorded.

RESULTS

85 patients were identified with an average age of 53.8 years (range 18-82); 67 (78.8%) patients were female. 78 patients underwent successful dTRA diagnostic cerebral angiography, with a mean of five vessels catheterized and average fluoroscopy time of 12.0 min, or 2.6 min for each vessel. Seven patients required conversion to transfemoral access, with the most common reason being inability to advance the wire and radial artery spasm. There were no complications.

CONCLUSION

dTRA is associated with decreased rates of radial artery occlusion, ischemic hand events, as well as improved patient comfort, faster periprocedural management, and cost benefits. Our preliminary experience with dTRA for diagnostic cerebral angiography demonstrates excellent feasibility and safety in combination with relative efficiency.