See also: Blow-by-blow account of robotic heart operation, “Joystick plays central role in new heart repair.”
New robotically controlled catheter tracks down heart abnormalities
Craig Schumacher’s heart operation was routine at first, but then it began to resemble a video game.
In the catheter lab at St. Jude Medical Center in Fullerton, Calif., the 56-year-old heart patient was stretched out on the operating table, draped, medicated, and anesthetized.
Cardiac electrophysiologist Dr. Rahul Doshi oversaw the placement of a slender cardiac catheter, which entered through Schumacher’s groin and snaked upward through his veins to the heart. It’s a procedure that Doshi has performed hundreds of times in operations to correct patients’ irregular heartbeats.
But this time the doctor stepped away from the operating table to sit at a bank of computer monitors. From there, he controlled the catheter with a joystick.
“This is pretty darn cool,” Doshi exclaimed after his first operation using St. Jude’s new Sensei robotic catheter system, made by Hansen Medical Inc. of Mountain View.
Schumacher’s procedure was two weeks ago, on July 31, the first day of operation for the $750,000 system. The device at St. Jude’s is the first of its kind in southern California and one of 21 installed nationwide.
“We now have hope again,” Schumacher’s wife, Ruby Cook, said after the operation. “We feel very blessed.”
That contrasts with their predicament three months ago, before Blue Shield and St. Jude worked through insurance problems and medical issues to clear the way for Schumacher’s latest high-tech treatment.
“It’s been a rough three years,” said Schumacher’s wife, Ruby Cook. Her husband has suffered from irregular heartbeats since surgery for cancer of the esophagus three years ago. He has repeatedly collapsed and been hospitalized.
Three times he has undergone a cardiac treatment called ablation, which is used to deaden portions of the heart where irregular electrical signals are causing irregular heartbeats.
Last year, during a trip to Yosemite National Park, he was evacuated by medical helicopter at a cost of $20,000. He has been hospitalized for seven months out of the past 12, including stays at hospitals near Yosemite, in Fresno and in Modesto, at USC Medical Center in Los Angeles, Placentia Linda Community Hospital in Placentia, Western Medical Center in Santa Ana, and UCI Medical Center in Orange, Cook said.
Schumacher is a carpenter, but he hasn’t been able to work and he couldn’t walk more than a few feet.
For a while, he had no prospects of further treatment because three ablations is typically the limit that doctors and health insurers set, she said.
But Doshi uses a different, sophisticated method of tracking electrical signals in the heart, so he and St. Jude, with support from Blue Cross, were willing to take on Schumacher for a fourth ablation procedure despite his prior history. That operation might have been done with a traditional catheter, but timing was such that Schumacher had the benefit of the new Sensei system.
FOUR-HOUR OPERATION
Doshi downed a can of Rock Star energy drink, then began the operation shortly after 2 p.m., starting by inserting the catheter deep inside the patient.
In the past, for the duration of the operation Doshi would have held the catheter at the end where its movement controls were located. Now the new Hansen catheter was attached to a computerized movement-control device that looked like a small vacuum cleaner suspended from a mechanical arm. (Pictured at right)
By 2:30 p.m., Doshi was seated at the new system’s work station (above left), holding the Sensei catheter’s joystick.
There, as he tracked down and eliminated electrical abnormalities in Schumacher’s heart, he sounded a bit like a computer gamer. It was his way of keeping spirits up in the operating room as he tackled a complex procedure that would determine Schumacher’s health for years to come.
On one screen Doshi could see the location of the catheter inside the chest, recorded by a five-foot C-shaped fluoroscope that encircled Schumacher’s upper body.
Everyone in the operating room wore lead-lined garments as protection against the X-rays the fluoroscope used to create its moving image of the patient’s heart.
A second screen showed the patterns of electrical signals inside the heart.
For nearly four hours, Doshi seemed glued to the screen as he hunted for abnormalities. Whenever he found one, he pressed a control lever with his foot. In response, the tip of the catheter emitted a blast of radio waves to deaden that spot.
The 3D image of Schumacher’s heart became dotted with dozens of white ovals that marked his newest ablation sites.Finally Doshi said, “We’re done.” The time was 6:07 p.m.
For a full account of the operation, see the post “Joystick plays central role in new heart repair” on Biomedication Innovation blog at innovation.freedomblogging.com.
THREE VIEWPOINTS
From Doshi’s viewpoint, the new robotic catheter is better for doctors and for patients.
By replacing manual control with computerized control, it will allow more accurate placement, he said.
“We can tackle more difficult situations and harder-to-reach places,” he said.
That should also help doctors cut down on errors, he said. Doctors will also be exposed to less radiation, because they will be working in front of the video screens instead of beside the X-ray-emitting fluoroscope.
From the viewpoint of some of the first medical researchers to test the Hansen device, the robotic catheter promises to be as good as manually controlled catheters. In medical journals, they gave it good grades, though not as high as Doshi did.
They also said some practical problems still need to be worked out, including occasional damage to the heart – at a rate that’s equivalent to the complications that occur with manual catheters.
Dr. Prapa Kanagaratnam of London and his co-authors wrote that they would have preferred to be able to feel in their hands how much force the catheter was applying to the heart, instead of just seeing its position on a monitor.
So far, the robotic system has proved to be “safe, feasible and effective,” although its long-term safety and effectiveness remains to be seen, they said.
The system might cut the length of ablation operations, which would reduce patients’ exposure to X-rays, Kanagaratnam said.
Dr. Walid Saliba of the Cleveland Clinic in Ohio and his co-authors reached a preliminary conclusion that the Sensei system does as well as conventional catheters, based on their experience operating on 40 heart patients.
Dr. Sabine Ernst, also of London, compared the Sensei system to a competing technology, the Niobe system from Stereotaxis Inc. of St. Louis, which uses powerful magnets to control the movement of the catheter. (Pictured at left) The Sensei system’s control mechanism consists of wires located inside the catheter sheath.
Both technologies are promising, Ernst said, but more data is needed to determine their relative strengths and weaknesses.
From the viewpoint of the patient, the surgery was a success.
Schumacher’s heart rate is more regular, he said, though it isn’t back to normal yet.
He was looking forward to returning home soon, after he recovers from a lung infection that he contracted after the surgery.
Then he hopes he can resume a more normal life.
“The obstacles I faced used to be the size of city blocks,” he said. “Now they’re just like cutting a hole in barbed wire.”
From the 7/4/2007 Biosense filing
In summarizing the patient injury, Biosense stated that
“The hansen robotic system is not 510(k) cleared for use with ablation catheters, therefore, this case was an off-label use.”
I looked up the FDA clearance letter and in it, the FDA commissioner asked that a warning label be prominently displayed on the Hansen robot as follows ” The safety and effectiveness of this device for use with cardiac ablation catheters, in the treatment of cardiac arrhythmias including atrial fibrillation, have not been established. ”
So why is Dr. Doshi using this robot for ablation when the FDA has a warning label on its usage for ablation? Do safety warnings from the FDA have any meaning or purpose?
Being an AFib patient myself, I would be interested in how the patient in the article is doing and whether his lung inflammation was a result of the procedure.