Gaining Insight Into Peripheral Interventions...Radial Access Can Play a Role

In this month’s edition, we welcome Terumo Medical Corporation’s new Chief Medical Officer, Dr. Michael Martinelli. Dr. Martinelli joins Terumo after a very successful career with St. Peter’s Hospital, in Albany, New York, where he practiced interventional cardiology, and held various positions of responsibility in the successful development and ongoing success of programs such as transcatheter aortic valve replacement (TAVR), peripheral intervention, and ST-elevation myocardial infarction (STEMI). It is in regard to the peripheral intervention program, and the treatment of peripheral arterial disease (PAD), that we talk to Dr. Martinelli today in order to gain his insights as to how his program not only addressed this disease process, but utilized the radial access approach. — Gary Clifton, Vice President, Terumo Business Edge

Welcome, Dr. Martinelli. Perhaps we could start with you telling us a little about your peripheral interventional experience.

In the early stages of our vascular program, we were primarily pursuing iliac, infrainguinal, and even visceral and upper extremity intervention via the femoral approach. At that time, alternate access via the transradial approach was in its infancy. Also, in regard to vessel access and closure, diagnostic catheters and therapeutic devices were primarily centered around the femoral artery.  As our radial experience began to grow and the advantages over femoral access, including access site complications, bleeding, patient comfort, and cost, were being demonstrated in coronary intervention¹, we began to consider radial access in the performance of peripheral interventions. Initially, we were limited by device length and could only pursue more proximal (primarily iliac and visceral) vessels. Industry is now quickly answering this growing demand and in fact, many peripheral interventions, in locations ranging from the aortoiliac space distally to the infrapopliteal vessels, are being performed via the transradial approach. Also, in distal lesions, the tibial/pedal approach has been gaining increased utilization.    

Your program was obviously hospital based. Can you tell us the pros and cons of a hospital-based program compared to what we have seen over the past 5 years with the rapid growth of these procedures being performed in an office-based lab (OBL) or an ambulatory surgical center (ASC)? 

The ability of the peripheral interventionalist to pursue a wide variety of upper and lower extremity procedures using radial (and pedal) access certainly lends itself to expedited discharge within the hospital setting, as well as in the outpatient setting. The significant experience in treating coronary artery disease (CAD) via the radial approach with regard to safety, reduced access site complications, reduced bleeding, early ambulation, and same-day discharge after percutaneous coronary intervention (PCI) certainly provides a springboard to the outpatient setting.² Of course, ultimately, case selection is of the utmost importance when transitioning to the outpatient setting. Patient co-morbidities such as renal function, cardiovascular issues, and the extent of vascular disease, as well as case duration, contrast volume, and patient compliance are just a few factors which may impact the need for inpatient observation post procedure. 

What is the expectation you have for medical device representatives who attend these procedures?

I have had a great deal of experience interacting with medical device representatives throughout my career, and have found many of them to be quite helpful and insightful. They may offer significant insight based on involvement in a variety of cases, and are often able to impart knowledge related to their experience with multiple cath lab procedures and protocols. I have met many representatives who are truly focused on patient care and successful outcomes, regardless of the device chosen. They are often willing to volunteer information regarding products from other companies which may work in synergy with their product or to suggest a device from another company which may perform better in specific clinical situations. These are the true professionals who are valuable and trusted members of the team.

Terumo now offers a radial to peripheral approach in terms of using a radial access approach to gain access to the periphery. What was your experience, and when and where do you feel this approach makes sense in the procedure? 

In my opinion, the radial to peripheral approach in performing diagnostic and therapeutic procedures offers advantages in addition to reduced access site complications and patient comfort. Use of the radial artery for selective imaging for diagnostic angiography or during intervention (from either a radial or femoral approach) can potentially decrease contrast use, as well as radiation exposure to the patient and physician.³ The available R2P Destination Slender Guiding Sheath and R2P SlenGuide Guiding Catheter (Terumo Interventional Systems) lengths (119 cm and 149 cm, and 120 cm and 150 cm, respectively) can be used to provide backup support for intervention at the iliac, femoral, and infrapopliteal levels. Also, when performing bilateral, simultaneous, iliac bifurcation stent intervention, the use of radial access and a single femoral access affords the operator the opportunity to perform a kissing balloon/stent procedure from above and below, thereby mitigating the risk of bilateral femoral access. A single radial access used to selectively cannulate the iliac vessels in succession affords the operator the ability to perform bilateral iliac intervention safely and at the same setting. The current radial to peripheral sheath or guide catheter once again can be positioned in the iliac or femoral system to address aortoiliac, infrainguinal, and infrapopliteal disease, and can improve support for the confident and successful use of longer platform devices (balloons, orbital atherectomy, self-expanding stents). In addition to potentially limiting contrast volume and radiation exposure, the use of a long sheath such as the R2P SlenGuide Guiding Catheter can reduce the need for long catheter exchanges and possibly mitigate radial artery vasospasm.  

Does it make sense that in an era where we can access via the radial and tibial/pedal arteries, that we could effectively eliminate the femoral approach for a majority of procedures? 

Although there is a strong movement to radial and pedal artery access in performing peripheral interventions, it remains extremely important for the radial operator to maintain skills for safe femoral access. Technology, however, is rapidly meeting the needs of the interventionalist by way of longer sheaths and interventional devices on longer shaft lengths, which can offer the operator more options to pursue state-of-the-art intervention. There are currently a wide variety of balloons which can be used in the infrainguinal and infrapopliteal space, as well as adjunctive devices such as orbital atherectomy (Diamondback 360 Peripheral Orbital Atherectomy System, CSI). We also now have access to self-expanding stents (R2P Misago RX Self-Expanding Peripheral Stent, Terumo Interventional Systems), making it possible to pursue stenting of the superficial femoral artery via the radial approach. Although there remain some unmet needs in the peripheral space, such as larger diameter, long access sheaths to assist in delivering large covered stents and a wider array of interventional devices deliverable from the radial artery, industry is rapidly recognizing these needs and “filling in the gaps.” Of course, as I have mentioned, many peripheral endovascular procedures such as aortic endografts will continue to require safe femoral access. Also, there will continue to be some patient-related difficulties with radial access, thus requiring femoral access. The ability to perform safe femoral access with the use of micropuncture needles, as well as imaging with fluoroscopy and ultrasound, is essential. It is also necessary for the operator to become facile in the use of large-bore closure devices.

For programs that have established strong radial access for coronary interventions, what recommendations do you have to prepare and begin deploying radial access for peripheral interventions? 

Certainly, a program with significant experience in radial coronary intervention is in excellent position to initiate a radial to peripheral program. Similar to access for coronary intervention, it is essential to mitigate pre- and intra-procedural radial artery vasospasm. The use of a “radial cocktail” consisting of nitrates and/or calcium blockers in addition to adequate sedation are mainstays in the avoidance and treatment of this problem.^6,7 The importance of recognizing and navigating radial loops, tortuous radial and subclavian anatomy, and recognizing anatomic variances such as accessory radial arteries is extremely important when moving to the peripheral vasculature. In order to successfully perform peripheral procedures via radial access using longer sheaths, it is very important to recognize and respond to post procedural vasospasm. This can be significant, but successfully treated in most cases with the judicious use of sedation augmented by intra-arterial vasodilators. 

You were involved with a hospital-based program. Do you see any differences in how these procedures should be approached via the ASC or OBL?  

I would reiterate that with thoughtful patient selection, to include careful attention to medical co-morbidities and social factors, a wide variety of peripheral interventions can be performed safely in an outpatient setting.⁴ The use of radial artery access and in many cases, tibial pedal access, has provided a safe and cost-effective way to achieve this goal.⁵ In addition, early ambulation, same-day discharge, and potential efficiencies of the outpatient environment will likely drive patient satisfaction. Radial artery access in coronary intervention has been demonstrated to reduce access site complications and bleeding, reduce cost, and improve patient satisfaction.^2,3 As peripheral interventionalists now have more access to devices designed for use from the radial approach, we can leverage what we have learned about the advantages of the radial approach, and enhance and accelerate the use of the outpatient setting for the treatment of peripheral arterial disease. 

R2P^™, DESTINATION SLENDER^™ Guiding Sheath, SLENGUIDE^™ Guiding Catheter, and MISAGO^® RX Self-Expanding Peripheral Stent are trademarks or registered trademarks of Terumo Medical Corporation. 

The Diamondback 360^® Peripheral Orbital Atherectomy System is a registered trademark of Cardiovascular Systems Inc. (CSI).