Techniques in Robotic Catheter Manipulation: Interview with Gregory Feld, MD

In this feature interview, we speak with Dr. Gregory Feld about his use of Catheter Robotics’ Amigo^® Remote Catheter System. Dr. Feld is a Professor of Medicine and the Director of the Cardiac Electrophysiology Program at UCSD Medical Center in La Jolla, California. 

Tell us about the Amigo Remote Catheter System and how it works. What are the components of the system?

The Amigo system is a remote catheter system that allows the operator to be located away from the table and x-ray, and to sit if they prefer. If desired, the physician can even sit in the control room. It consists of a mechanical arm that attaches to the table and has a fairly small profile, unlike some of the other robotic systems. 

Amigo manipulates the catheter in a manner that you’re used to, but there is no feedback because there is no built-in force contact sensor in the Amigo system. However, Amigo preserves the catheter’s built-in safety features such as bending and bucklingunder too much force. I think the risk of extra pressure and perforation is reduced with the contact force measuring catheters that are currently available for use. We identify force either using the recently approved contact force catheter manufactured by Biosense Webster, Inc., or by measuring tissue interface temperature with a non-irrigated large tip ablation catheter, for example, the 8 mm tip electrode Blazer catheter manufactured by Boston Scientific, Inc. The Amigo system manipulates the catheter like one would by hand; therefore, if you’re experienced with that, it becomes very simple to understand the controller. 

The catheter is placed into a docking station, which is specific to your catheter of choice. This docking station is seated into the arm and securely holds the catheter. The catheter is then guided by user inputs into the controller. These inputs correspond with 

insert, withdrawal, rotation and tip deflection. The motions are mechanical and can move in micro-increments. Amigo uses third party catheters, introducers and mapping systems allowing it to be fully compatible with any lab. 

How long have you been using the Amigo system? About how many cases approximately have you used them on?

At this point, I would say we’ve done at least 30-40 cases with the Amigo system. I’ve used it on virtually all types of atrial arrhythmia cases, including WPW syndrome, AV node reentry, atrial fibrillation, and atrial flutter. We haven’t yet used it much to treat ventricular tachycardias, but I think it’s certainly feasible to use it in the ventricle because the catheters are easily manipulated. 

What was the learning curve like with the Amigo system?

It’s very fast. As I mentioned before, it manipulates the catheter more or less the same as you would with manual manipulation, so there is no unusual skill set required. It’s very intuitive. During the U.S. clinical trial, Amigo was shown to have a learning curve of 3 patients. 

What is the setup procedure and how long does it take?

It probably takes an extra 10-15 minutes to set up, so not very much additional time. The staff places a sterile cover over the robotic system, and the operator puts the control handle in a sterile wand bag (similar to a pacemaker setup), and then the catheter is put through a sterile tunnel in the Amigo system. The setup takes only about 10 or 15 minutes, which is not significant for the staff. The other robotic systems are a little bit more involved, but the Amigo system is fairly straightforward.  

What are the benefits of the Amigo system?

There are several benefits with a robotic system. One is that it allows the operator to work some distance from the x-ray, which is a definite advantage with the Amigo system, since the controller has a cable up to 100 feet. The second aspect is that it allows the operator the option to sit down and do their case. Standing at a table for many years puts the operator at risk for developing orthopedic problems in their neck, back, hips, and knees. So reducing risk of orthopedic injuries and limiting exposure to fluoro are both advantages of the Amigo system. 

How does catheter tip stability compare?

The ability to hold the catheter stable is an important factor. When you hold a catheter in the heart tissue, the heart is moving, and you’re moving your hands a little too. It depends on how steady you are, but the catheters are a little unstable. We think this system allows you to get better catheter stability and produce a better ablation lesion.

In fact, we’re going to be doing a study comparing the ability to manually maintain contact force over time versus the robotic system. We’ll be comparing contact force produced by the robotic system versus manual catheter manipulation over the duration of the ablation of the cavotricuspid isthmus for atrial flutter. We’ll be getting that study done in the next couple of months. 

Is there anything else you’d like to add?

I think the improvements to the operator’s physical health as well as increased stability of the catheter system for ablation are very important. We’ve been quite pleased with the Amigo system. It’s a very easy setup, requires a short learning curve, and has proved to be useful for us. 

Disclosure: The author has no conflicts of interest to report regarding the content herein.