Remote Catheter Navigation Systems

Key Points

Remote catheter navigation systems currently comprise electromagnetic and electromechanical technologies. Four remote systems are currently available.
Each navigation system has both advantages and disadvantages with substantial variation in the cost, learning curve, and procedure applications.
Potential advantages of remote navigation system are reduced operator radiation exposure and physical stress, improved catheter stability, enhanced patient safety, and automated mapping (in some instances) and catheter navigation.
Remote catheter navigation systems have not yet been demonstrated superior to manual navigation in procedural success or total procedure times, although fluoroscopic times are generally shortened.

Introduction

The field of electrophysiology (EP) has evolved significantly over the last 3 decades. Before the advent of ablation procedures, EP procedures were diagnostic studies. These were usually tedious and time consuming, but with catheters remaining stationary in specific cardiac locations for the majority of the procedure. With the development of various ablation techniques, therapeutic endeavors involved precise, deliberate, and frequent catheter movements. Throughout this progression and increased complexity, procedure duration has increased and manual dexterity requirements have become ever more important. All of this was occurring in an environment that involves standing for hours in a lead apron, in a room with significant radiation exposure. The length of time required to master the skills and the physical toll from the day-to-day wear are onerous. The concept of remote catheter navigation has the advantage of allowing the operator to perform the procedures while sitting, away from the radiation source. Furthermore, robotic or other nonmanual manipulation techniques may theoretically offer improved and stable catheter movement as well as either shortening the learning curve or reaching locations that might be more difficult to reach manually. This chapter provides a description and comparison of four currently developed remote systems, namely, the Amigo Remote Catheter System (Catheter Robotics, Mount Olive, NJ), the Sensei Robotic System (Hansen Medical, Mountain View, CA), the Niobe Magnetic Navigation System (MNS; Stereotaxis, St. Louis, MO), and the Catheter Guidance Control and Imaging (CGCI; Magnetecs, Inglewood, CA).

Amigo Remote Catheter System, Catheter Robotics

Amigo ( Fig. 8.1 ) is a remote catheter manipulation system composed of a robotic arm mounted directly on the railing of the EP fluoroscopy table connected to a wired controller ( Fig. 8.2 ). Unlike other systems, Amigo incorporates minimal additional hardware beyond the equipment required for a standard manual procedure. Because it is self-contained, compact, and does not require calibration, Amigo can be moved from one room to another with relative ease. This system is an open-platform system that is designed to accommodate bidirectional catheters with the Blazer (Boston Scientific, Marlborough, MA) or EZ Steer (Biosense Webster, Diamond Bar, CA) handle platform. The catheter to be robotically controlled is placed on the docking station and is driven by the wired controller, which may be up to 30 m (100 ft) from the patient. Manual catheter movements are mimicked robotically at the bedside catheter using the controller, which emulates a bidirectional EP catheter handle. Unlike other technologies, only the catheter and a standard sheath are inside the patient. Catheter movements are distilled into three basic actions, namely, catheter-tip deflection, rotation, and advancement/withdrawal. Catheter-tip deflection is achieved by placing the catheter handle into the Amigo docking station, which controls the bidirectional steering element. Any deflection command performed on the controller is duplicated with the catheter through the docking station. Use of the catheter tension knob is not required as the system can hold a precise position indefinitely. Rotation of the catheter is accomplished by twisting the tip of the controller. This command causes the turret and the catheter to rotate. Because the nose cone and track of the Amigo do not actually rotate, rotation is not impeded by sheath rotation. Finally, catheter advancement and withdrawal are performed by pressing buttons on the side of the controller. This command causes the docking station to advance or withdraw on command along the track of the Amigo system at a rate of 13 mm per second (0.5 inches per second). Because Amigo manipulates only the mounted catheter, sheath placement is identical to that of a manual procedure. To avoid unintended catheter movement, an infrared (IR) beam and a receiver are incorporated into the controller. Only commands that are performed by the controller while being held by the operator (thereby interrupting the IR beam) are actuated. The Amigo does not further integrate into a mapping system. Therefore all 3-dimensional mapping products are used in an identical fashion to that of a manual procedure.

Fig. 8.1, Demonstration of the Amigo Remote Catheter System. The Amigo robotic arm connected to the side of a draped fluoroscopy table. The wired controller is shown in the operator’s hand.

Fig. 8.2, Close-up view of the Amigo wired controller.

Sensei Robotic System, Hansen Medical

The system consists of two primary components, namely, the Sensei Robotic System and the Artisan Extend Control Catheter, a remotely controlled steerable sheath ( Fig. 8.3 ). The physician remotely directs the movement of the steerable sheath through the Sensei Robotic System—an electronically controlled mechanical system for remotely controlling the Artisan. The Sensei consists of a physician workstation, an electronics rack, and a patient-side remote catheter manipulator (RCM; Fig. 8.4 ). The system allows the clinician to direct the catheter tip to a desired intracardiac location based on visual feedback from 3-dimensional maps, fluoroscopic images, and intracardiac echocardiography images while being seated at the workstation. The RCM electromechanically manipulates the steerable guide catheter in response to commands received from the physician through a special 3-dimensional joystick (intuitive motion controller, or IMC) at the physician workstation (see Fig. 8.4C ). The basic principle of the system is that operator input is intuitive relative to an image in the navigation window monitor, which is in the center of the monitor console. The Artisan sheath is a pull wire–actuated open-lumen steerable guide sheath system. It is comprised of a flexible inner guide sheath with an inner diameter of 8 F and steerable outer guide sheath that fits through a standard 14 F hemostatic introducer. The Artisan attaches to the RCM through a sterile drape barrier and the RCM in turn actuates the catheter pull wires in response to commands from the physician. The Artisan is a guide sheath and is not capable of therapy or diagnostics on its own. Rather, any commercially available ablation catheter can be placed into the Artisan, with just the distal two electrodes extending beyond the inner guide tip. The Artisan can articulate in any direction up to 275 degrees, with a minimal working curve diameter of 30 mm ( Fig. 8.5 ). Of note, in 2016 Hansen Medical was acquired by Auris Surgical Robotics (San Carlos, CA), and, as of June 2017, the future of this technology is uncertain.