Lower Complications Lead Neurosurgery Toward 'Radial First'

Nancy A. Melville

June 30, 2020

The latest evidence on the safety of switching from transfemoral access to transradial access in neurosurgery indicates important benefits through a reduction in complications once a notable learning curve is overcome.

"After propensity-adjusted analysis, transfemoral access procedures were found to be a major risk factor for a complication compared with transradial approaches," said first author Joshua Catapano, MD, in reporting on the experience with a "radial first" policy at the Barrow Neurological Institute, in Phoenix, Arizona. His presentation was part of the virtual American Association of Neurological Surgeons (AANS) 2020 Annual Meeting.

"Although a steep learning curve is initially encountered when using the transradial approach, our results suggest that the transition to a 'transradial first' practice can be performed safely, with a minimal loss in efficiency," he said.

The ability to access arteries through transradial catheterization, which involves entry through the wrist, as opposed to transfemoral catheterization, which involves entry through the groin, has gained favor in cardiology, where the approach allows for an optimal angle into the coronary arteries. The approach has been shown to improve outcomes and patient satisfaction and to reduce cost.

In light of evidence showing reduced bleeding, fewer vascular complications, reduced adverse events, and shorter hospital length of stay, the American Heart Association recommends a "radial first" strategy for acute coronary syndrome patients in its guidelines.

However, in the neurointerventional arena, the shift from the transfemoral to the transradial approach has been somewhat more challenging. For cerebrovascular access via the transradial approach, catheters must be reconfigured to catheterize major neck vessels, coauthor Andrew Ducruet, MD, also of the Barrow Neurological Institute, explained to Medscape Medical News.

"The transradial approach for neurointervention is relatively new, and many practitioners still lack experience with these techniques," he said.

"The major reservations are mostly from a lack of experience and familiarity with techniques of access, as well as issues regarding size and compatibility of larger guide catheters with radial access," he said.

Evidence has shown key benefits of the radial approach in neurology, however, including improved access to the vertebrobasilar system, ease in navigating complex arch anatomies, such as bovine and type III arches, and reductions in ischemic complications owing to robust collateral circulation from the ulnar artery, Catapano said in his presentation.

Transfemoral vs Transradial

To compare outcomes with the two approaches in neuroendovascular procedures, the authors conducted a propensity-matched analysis of the use of these approaches during the initial period in which a transradial-first approach was adopted in neuroangiographic procedures performed between October 2018 and June 2019.

During the study period, 844 (80%) transfemoral procedures and 206 (20%) transradial procedures were performed. In October 2018, at the beginning of the study period, the radial approach was used for only 1% of cases; by June 2019, they were used for about 70% of cases.

Overall, the complication rate was significantly higher with the transfemoral procedures (transfemoral: 7%, 60 complications; transradial: 2%, four complications; P = .003).

The rate of minor complications was 6% (47) in the transfemoral group, vs 2% (three) in the transradial group (P = .01). Major complications occurred in 2% (13) in the femoral group and 0.5% (one) in the transradial group, which was not statistically different.

Diagnostic vasospasm complications occurred in 30% (six) of the transfemoral group, vs just 1% (one) in the transradial group (P = .007).

After propensity-score matching that adjusted for age, sex, sheath size, catheter size, procedure, and angiographic pathology, the odds of complication with the transfemoral approach were more than three times higher (odds ratio [OR], 3.6; P = .01).

Interestingly, the fluoroscopy times were significantly lower with the transfemoral procedure compared to the transradial (OR, –4.0; P = .003), and the transfemoral group received 10 cc less contrast (P = .09).

The average age of the patients in the study was about 60 years. In the majority of cases, and procedures were diagnostic for vasospasm (62% of femoral and 72% of radial procedures).

A much higher percentage of thrombectomy procedures was performed in the transfemoral group (16% vs 4%). The rate of diagnostic procedures, such as for vasospasm, was higher in the transradial group (72% vs 62%), the authors noted.

In the transradial group, the percentage of normal pathology was higher (20% vs 14%), there were more aneurysms (42% vs 36%), and the percentage of acute strokes was lower in comparison with the transfemoral group (1% vs 10%).

"There were no life-threatening complications with the transradial procedures, while five major complications were found with the transfemoral approach that were life-threatening," Catapano said.

"These included two occlusive/near occlusive femoral arteries, one retroperiotoneal bleed, and two large intracranial hemorrhages.

"Diagnostic procedures with transfemoral approaches were found to have an increased complication rate as well," he said. "These are relatively benign procedures, and transradial access makes them even safer."

All of the complications that resulted with the radial approach occurred among the first 60 transradial cases; none occurred afterward.

Furthermore, the mean transradial fluoroscopy time was greatest in the first 40 cases. It dropped from 41 minutes to 36 minutes in the remaining cases.

Proximal vs Distal Access

There were no significant differences in access site crossovers or complication rates between the proximal and distal radial approaches. The mean fluoroscopy time was 5 minutes shorter in the distal radial access group.

"This is likely due to the distal procedures being performed during the latter part of the study and greater operator expertise," Catapano said.

Although sheaths and catheters of larger size were used in the proximal transradial approaches compared to the distal, those differences likely occurred because a larger number of treatments were performed with those procedures.

Key Strategies Can Reduce Complications

Ducruet noted that most complications in the study period were the result of inexperience in achieving access to the radial artery and use of manual compression for closure. He suggested key measures for preventing such events.

"Strategies to minimize complications include eliminating drips on the sheath, obtaining radial artery angiogram following access, the use of nonocclusive closure bands for both proximal and distal radial access, and the judicious use of long sheaths for intervention cases," he said.

With such strategies, the transradial approach can be safely utilized, Ducruet said.

"Currently, we have implemented a radial artery–first practice, and virtually all procedures are being performed via transradial access," he said. He noted that patients who are familiar with the approaches typically prefer the transradial approach.

"We have had several patients who have read about radial access through various sources, including social media, who request radial access," Ducruet said.

"Patients who have had experience with both types of access unilaterally prefer and request radial access."

Anatomic Navigation a Key Skill

Robert H. Rosenwasser, MD, the Jewell Osterholm Professor and chair of the Department of Neurological Surgery at Thomas Jefferson University, Philadelphia, Pennsylvania, noted that the primary challenges with the radial approach in neurology are in anatomic navigation.

"Intracranial navigation is somewhat more tortuous than cardiac intervention per se, and so, therefore, sometimes that is an issue," he told Medscape Medical News.

"About 18% of the time, there is a crossover from the radial to the femoral route, particularly for cervical and intracranial carotid revascularization, again due to the anatomy."

Rosenwasser added that, as was the case at the Barrow Neurological Institute, the initial contrast load was higher at his center, "but that is really a nonissue now, [as we are] approaching 1000 transradial cases for diagnosis and therapeutic intervention," he said.

Patients are requesting the radial approach at his center, Rosenwasser said.

"And we are certainly offering [transradial access] to them for virtually 100% of the outpatient procedures unless there is an anatomical or physiologic contraindication," he said.

The authors and Rosenwasser have disclosed no relevant financial relationships.

American Association of Neurological Surgeons (AANS) 2020 Annual Meeting: Abstract 200.

For more Medscape Neurology news, join us on Facebook and Twitter.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.