Tom Krigar was dedicated to staying healthy after open heart surgery 10 years ago. At first he had to make a job change and start driving a school van. In his time off, he would exercise on his treadmill and go hunting with his dogs.
But a little over a year ago, pain in his calves made walking unbearable. It took some time to diagnose his problem, known as claudication as a result of peripheral artery disease, but it was treated with new technology now being tested as a possibly safer alternative to other catheter-based plaque-removal tools.
Mr. Krigar, 64, of Adams in Butler County, said he had already experienced numbness in his feet, but doctors couldn’t find the cause of pain, which affected both legs.
“And then this past June I couldn’t go on the treadmill,” he said. “I was going 4.2 miles for 50 minutes on a 12 percent grade, but I couldn’t do it anymore.”
He was treated for neuropathy by a neurologist, checked by his cardiologist but continued to suffer pain.
“I was going hunting in the fall with my son and daughter… We have a black Lab and started hunting pheasant. I was crawling through the woods. I felt like a guy with two wooden legs.”
His family doctor said, “You don’t have a good quality of life, do you?” And Mr. Krigar had to agree. The doctor sent him to Bart Chess, vascular surgeon at Allegheny General Hospital, who found plaque build-up in his leg vessels through a test and then performed a catherization.
“They came up against 100 percent blockage,” Mr. Krigar said. “They couldn’t push it through.”
All blockages do not need sophisticated tools, according to Rabih Chaer, vascular surgeon at the University of Pittsburgh Medical Center. The goal is to get to the opposite side of the blockage, he said, and UPMC surgeons use wire leads on catheters to traverse it.
“Once it’s traversed, there are multiple devices that you can use to unplug the the artery,” Dr. Chaer said, Options include balloon angioplasty to push an opening in the plaque and, if needed, a stent to keep the vessel open. Cutting out the plaque is also an option, he said. In some cases bypass surgery is the best treatment.
Mr. Krigar was offered a new plaque-removal treatment, which differs from the wide use of X rays and a touch-and-feel technique to guide a catheter-based cutting tool through the arteries.
His surgeon, Dr. Chess, is part of a team of vascular surgeons at Allegheny Health Network testing the use of optical coherence tomography to light the path of the surgeons’ work. They use catheters, called Ocelot and Pantheris, made by Avinger, a medical device company. Ocelot creates a small channel through a completely blocked vessel, then Pantheris cleans out the blockage and stores the material in a chamber at the end of the catheter for removal.
With the laser-based imaging system showing progress in real time, artery walls are protected as the Pantheris tool inside the catheter rotates and removes the plaque. A balloon cushioning the non-cutting side of the tool pushes the blade toward the plaque.
The high-speed Pantheris replaces “blind cutting,” said Satish C. Muluk, director of the division of vascular surgery and vice chair of AHN’s department of thoracic and cardiovascular surgery.
“You can see the blockage,” he said. “Because you can stay inside the vessel, you can avoid damage to the other parts of the vessel.”
Mr. Krigar said his Pantheris/Ocelot procedure was on April 6, and he was told the plaque in that artery was completely removed and no stents were needed to keep the vessel open.
“By the end of April I started walking on the treadmill again… Now I’m up to a 9 percent grade, 4 miles per hour for 50 minutes. I’m almost back to where I was before.
“I still have neuropathy … but I walk pretty good now. I go out in the woods with the dog now and don’t have any pain.”
Dr. Muluk said patients with PAD who have no symptoms can be monitored with ultrasound. But, he said, if there is limping and pain because of lack of blood flow, it can interfere with a person’s quality of life.
Dr. Muluk said the most severe situation is when patients have ischemia — pain when they are at rest and some loss of tissue because of the lack of blood flow.
“That group of patients is in dire need of treatment. With vascular intervention, they can avoid limb loss.”
Often people discover they have PAD because they are being treated for heart disease, but Dr. Muluk said many people don’t get angiograms and don’t know there is plaque buildup in their arteries. People who smoke or have diabetes are at the greatest risk of getting PAD.
For some patients, Dr. Muluk said, the plaque-removal treatment is a springboard to take steps to change their lifestyle and get their health issues under control.
Highmark Health’s VITAL Innovation Program pays for the launch of the Ocelot and Pantheris systems at Allegheny Health Network, as part of its mission to study new technology after FDA approval and before full reimbursement by commercial insurers.
Dr. Chaer, the UPMC vascular surgeon, said he also anticipates future solutions to enable the unblocked blood vessels to stay open and give patients lasting improvement.
“We want to be able to make a procedure that is a durable procedure,” he said. “New technologies and new devices and stents will hopefully improve the durability of the intervention and allow [patients] to keep their limbs and be asymptomatic.”
Jill Daly: jdaly@post-gazette.com, 412-263-1596.
First Published: July 5, 2016, 4:00 a.m.
