Patrick M. Hranitzky, MD, sits at the controls of the Hansen Medical Sensei X Robotic Catheter system.

Sponsored by Hansen Medical

The field of electrophysiology is increasingly moving toward performing more and more complex cardiac arrhythmia procedures. These procedures, which can last up to four hours, demand steady hands, a sturdy back and great concentration. Employing the latest technology, particularly robotic assistance, is helping electrophysiologists gain more catheter control, reduce overall procedure time and radiation exposure, and increase their clinical confidence.

In this issue of Cardiovascular Business, we’ve asked Patrick M. Hranitzky, MD, an assistant professor of medicine and director of the Clinical Cardiac Electrophysiology Fellowship Program at Duke University Medical Center, Durham, N.C., to discuss his use of the Hansen Medical Sensei Robotic Catheter system, which is cleared for mapping complex cardiac arrhythmias.

Instinctive motion control
When Duke initially purchased the Sensei system, the medical center was in the process of building new EP labs. The robotic system found a home in an old lab and was moved to a new lab upon completion. That portability of the system was a factor in the purchase of the technology. “We wanted the technology immediately, but we also knew we’d be moving it. The Sensei platform is very flexible in that regard,” Hranitzky says.

Hranitzky and his EP colleague, Tristram Bahnson, MD, have had the Sensei system for about two years. The robotic system operates by manipulating a steerable sheath at a workstation from outside the EP lab. More recently, the Duke team has upgraded to the Sensei X, the next-generation flexible, robotic platform that integrates advanced levels of 3D catheter control with 3D visualization.

The Sensei system has instinctive motion control technology that accurately translates the clinician’s hand motions at the workstation to the control catheter inside the patient’s heart. “When you have that kind of enhanced precision, there is less of a need to repeat steps. At this point it’s anecdotal, but I believe our overall procedure time has been reduced,” Hranitzky says.

Word has spread about the advanced technology at Duke. Cardiologists in the area without the robotic system will often call Hranitzky to discuss cases and determine whether they should be referred to Duke. He recounts mapping a few Wolff-Parkinson-White cases referred from outside institutions that found the cases problematic. Wolff-Parkinson-White can be particularly challenging for catheter stability when the accessory pathway is on the right free wall of the heart. “The Sensei system has been excellent for these,” he says. “These cases are a perfect example of how the ability of the system to keep a catheter stable is so important.” And the referrals help the bottom line.

Besides word of mouth advertising, Duke has positioned the Sensei system in its marketing campaign as a significant competitive advantage over facilities that do not offer it.

Studies of the Sensei robotic system generally mention a learning curve. Hranitzky says he became facile with the technology after about 10 to 12 cases. At first, he found himself doubting the stability of the catheter. He’d continuously watch the catheter to see how it was moving around on the heart. Once he realized he could trust the technology—that the catheter movements accurately reflected the motion controller movements—he assumed a clinical confidence that allowed him to proceed more quickly. “In addition, the excellent contact of the catheter helps complete the case faster, further reducing procedure and fluoroscopy time,” he says.

Reachability & CoHesion
The Sensei X system is designed to work with the newest generation Artisan Extend Control Catheter, which allows physicians to map in hard-to-reach anatomical locations. Hranitzky says he has found the Artisan Extend to be particularly useful in patients with small hearts. “With the previous-generation catheter, there was a significant area of the heart we couldn’t reach. With the Artisan Extend, our reachability—and bend—has increased, which I believe allows us to navigate much smaller areas easier,” he says.

The Artisan Extend also has a shorter setup time, the mechanism of flushing and priming being improved and streamlined from earlier-generation catheters. “It has helped to enhance our workflow,” Hranitzky says.

The EnSite advanced mapping system (St. Jude Medical) provides visualization and localization for detection of EP catheters in 3D space. The CoHesion 3D Visualization Module, available on the Sensei X platform, seamlessly integrates the EnSite mapping system with the robotic technology. “The CoHesion interface is truly innovative because it allows for very accurate 3D catheter manipulation and catheter stability,” Hranitzky says.

It’s fairly standard in the U.S. for EP patients to undergo a CT or MRI scan before their EP procedure. The purpose of the imaging is to get a 3D picture of the cardiac anatomy, especially the pulmonary veins, for mapping. But while most people have two pulmonary veins coming from the right and two from the left, there are all kinds of iterations, Hranitzky says. “Having those images gives us an idea pre-procedure of the origins of the pulmonary veins and if there might be small veins missed on pulmonary venography.”

CoHesion allows EPs to import the 3D anatomical model from the St. Jude Medical Ensite system directly into the Sensei system. The beauty of CoHesion, according to Hranitzky, is that it orients the 3D image in either the AP or lateral view. “We didn’t have that capability before CoHesion,” he says. “We had to mentally orient the images in at least one view.”

Good vibrations
The older generation technology only included a visible graph on the monitor that displayed the tissue contact force. “It was a little challenging,” Hranitzky says, “manipulating the catheter on one monitor and having to look at another monitor to see the force being measured.” The Sensei X has eliminated that problem by including IntelliSense Fine Force Technology with Tactile Vibration. Now, the operator can feel vibrations through the instinctive motion controller relative to the amount of force being measured, in addition to viewing the monitor.

“When I get that tactile feedback, I’m able to respond quicker than if I were looking at several screens,” Hranitzky says. “In addition, I get a better understanding of the force being measured and know immediately what the catheter contact is.”

Shed the lead
There is something to be said about increased physician comfort with the Sensei. One of the biggest advantages of the system, says Hranitzky, is the ability to do cases from a seated position outside the lab. Not only do you avoid radiation exposure, but you do not have to wear 20 pounds of lead for several hours. Older electrophysiologists often suffer from orthopedic problems, such as neck and back pain, as a result of wearing a lead apron for long complex procedures year after year.

“The Sensei system may end up extending our longevity,” Hranitzky says. “That was a big selling point for us at Duke. For younger physicians with years of practice ahead of them, this system may allow them to enjoy a long career without orthopedic problems. For older physicians who may already have neck and back problems, this system can allow them to stay off their feet and extend their careers as well.”

With the ability to reduce procedure time per case, coupled with sharper, less tired physicians in the afternoon, a facility could feasibly add more cases to their mix on any given day, Hranitzky says.

The Sensei X Robotic Catheter system offers many advantages for electrophysiologists and their facilities, including improved catheter control and platform flexibility. Hranitzky’s positive experience with the Sensei system is not unusual with those who have adopted this advanced technology. Most importantly, however, the technology assists patients with having a better quality of life.

Note: The safety and effectiveness of this system for use with cardiac ablation catheters in the treatment of cardiac arrhythmias, including atrial fibrillation, have not been established.