New Technology Enables Better “Feel” for Catheter

Father John Coleman noticed during his recent electrophysiology procedure that while attentive nurses were by his side, his physicians, Paul Wang, MD and Amin Al-Ahmad, MD, were usually working some 15 feet away. It took Coleman a bit of time to realize that the doctors’ distance from the catheter moving inside him was a signature feature of the new robotic arrhythmia ablation procedure he had signed on for.

“Everything seemed to go like a piece of cake,” Coleman recalled in July, two months after his May 19 procedure at SHC’s Cardiac Electrophysiology Laboratory.

Within weeks of Stanford Hospital and Clinics’ first procedure using the catheter-controlled console, Coleman was back on the golf course, usually shooting just a few strokes over his age of 83, and back at his duties as a retired but still active priest at East Palo Alto’s Saint Francis of Assisi Church.

For Wang, director of the Cardiac Arrhythmia Service and Cardiac Electrophysiology Laboratory, the procedure and Coleman’s enthusiasm is emblematic of his team’s belief that “when we deploy a new procedure we rejoice in the things we have and then move on to find a better way. We don’t look to new technology, we look for an enabler.”

Hansen Medical’s Robotic Catheter Control System became a reality because Al-Ahmad, associate director of the Arrhythmia Service, helped conceptualize and design the system after he observed the benefits of robotic surgical technology in urological and gynecological surgery.

“I asked myself and colleagues, why can’t the technology used so successfully in surgical procedures be adapted to the electrophysiology lab,” Al-Ahmad recalls, noting that some of the patient care delivery issues were similar. Both procedures required delicate control of instruments in situations where tactile cues were not definitive in guiding the instrumentation. That was particularly true in ablation, where indirect controls and a beating heart converge.

The robotic technology, say Wang and Al-Ahmad, is the latest but surely not the final step in solving a fundamental problem of “feeling” the catheter.

“Catheters require a lot of experience and a lot of skill,” says Wang, “so what we are moving toward here is a device that we can control with true precision. In 2009, the robotic catheter with a control console offering tactile feedback, is as close as you can get to holding the tip of the catheter in your hand right on the worksite, which in this case happens to be a beating heart. But we’re always looking ahead.”

While the system is still being fine-tuned, Al-Ahmad says that the robotic system provides haptic feedback through the console, offering a more objective measure of contact force and tissue parameters via the system’s robotic tracking than even the most experienced cardiologist can achieve while manipulating a catheter a meter away from the doctor’s hand in a beating heart. The console-operated controls provide real time force-sensing quantification as the catheter moves within the heart.

“The robotic arm can follow a ‘roadmap’ more precisely than any physician manipulating a catheter by ‘feel’. It’s really that simple,” Wang explains.

Currently, Wang says patients with complex atrial arrhythmias are potential candidates for a robotic procedure. The next step, he says will be ventricular arrhythmias, “a complex arena where we believe Stanford has developed significant expertise.”

And the next generation, says Al-Ahmad, will put the controls on autopilot, providing physicians with truly objective data. Patients can be “measured,” says Al-Ahmad, using fluoroscopy and 3-Dimensional CT scan technology, so the device can be programmed to follow a precise roadmap to complete the procedure.

Moreover, road mapping offers important benefits in education, say Wang and Al-Ahmad.

 “We can plug a patient’s anatomy into a simulator and rehearse the procedure. Trainees at a variety of levels can practice a procedure on a real patient’s computer-generated anatomy, bringing the level of practice throughout the country to new heights,” Wang says.

When he talked to Hansen in 2004, both the company and Al-Ahmad saw the potential that cardiologists who perform a relatively small number of procedures each year would benefit immediately from the predictability of computer-based controls.

“And beyond that,” says Wang, “the ultimate benefits of the user friendly technology will be seen when you push the envelope and use the system to go where you haven’t been able to go before.”

Put simply, Wang said the tracking device will allow highly experienced cardiologists such as his team to offer procedures to patients who before might not have been viable candidates for a minimally invasive procedure. Centers like Stanford can use this technology to pave the way for the future of ablation.

“Robotics allows the user to concentrate and focus his or her attention more closely on the patient during the ablation procedure rather than on how to get a manual instrument to move around in the heart.  This change of focus allows us to step back and tackle the complexity of the patient’s rhythm problem,” Wang says.

Despite the benefits of robotic ablation, both Wang and Al-Ahmad see the system as “something to be integrated into our overall program. “Technology doesn’t drive what we do. We pick the technology that solves the patient’s problem,” Wang says.

Wang and Al-Ahmad are quick to point out that at nationally recognized centers such as Stanford, there are a number of new technologies being pioneered and tested.  Stanford, for example, has been at the forefront of the development of balloon ablation technologies, such as cryoablation technologies, which show enormous promise for the treatment of atrial fibrillation.

Wang also notes that the team continues its search to find better ways to treat arrhythmias.

And among their current dreams is a totally robotic system that will replace hand-manipulated catheters that like a moon rover can enter the vascular system and perform ablation without catheters as we now know them: “A little guy who moves around inside the heart.”

That technology is down the road, admits Wang. “But our mantra is that in our quest for a better way to do things, we never stop.”

 

The Arrhythmia Service and Cardiac Electrophysiology Lab faculty include Paul Wang, MD ; Amin Al-Ahmad, MD ; Henry H. Hsia, MD ; Karen Friday, MD;   Paul C. Zei, MD, PhD; and Mintu Turakhia, MD, MS. A highly experienced group of arrhythmia nurse specialists, technicians and support staff round out the team.

• Atrial fibrillation and atrial flutter

• Supraventricular tachycardias

• Ventricular tachycardias

• Arrhythmias in heart failure and cardiac dysfunction

• Arrhythmias in hypertrophic cardiomyopathy

• Inherited rhythm disorders

• Arrhythmias in congenital heart disease

• Syncope and autonomic dysfunction

• Arrhythmias in women

• Arrhythmias after heart transplantation

• Device infections

• Catheter ablation of atrial fibrillation, atrial flutter, supraventricular tachycardias and ventricular tachycardias

• Cardiac electrophysiologic testing

• Implantation of pacemakers, implantable defibrillators, resynchronization devices, implantable loop recorders

• Device and lead extraction

• Cardioversion and tilt table testing