For people who suffer with peripheral artery disease, the pain that comes just from a stroll around the block may be uncomfortable or it may be downright debilitating. As plaque clogs hip or leg arteries, the results can be painful cramping, leg numbness or weakness, and coldness in the lower leg or foot.
That’s when Daniel Wunder, MD, a board certified vascular and interventional radiologist, steps in. One of his most effective tools to tackle the problem is the SilverHawk™ Plaque Excision System. Wunder has been with Premier Radiology, an affiliate of the Saint Thomas Imaging Network, for 13 years and said he’s one of Middle Tennessee’s most frequent users of the SilverHawk device.
Wunder uses imaging guidance for all his procedures, and X-ray is what guides his work with the SilverHawk. “I describe it to my patients as a Roto-Rooter,” he said. “That’s not exactly how it works, but they understand it.” Wunder explained that the SilverHawk is “a re-innovation of a catheter that used to exist, but it’s been refined.”
A tiny blade on the tip of the SilverHawk catheter rotates when activated and removes the plaque from the arterial wall. Adding to the SilverHawk’s effectiveness is that it’s not like other solutions for plaque buildup, such as angioplasty and stenting, which push the plaque to the sides where it can re-grow and eventually re-block the artery. Instead, the SilverHawk tool allows the surgeon to collect the plaque and remove it from the artery entirely.
“It’s like opening up your pipes,” Wunder said. The surgeon works through a sheath, a tiny sterile tube into which the catheter is inserted. After the procedure, the ⅛-inch hole in the artery wall after the sheath is removed is sealed with a stitch that dissolves in two or three months, Wunder said. Patients are up and about within an hour or two. Should patients need work on both legs, Wunder recommends a period of two to three weeks between procedures.
Wunder said he has encountered arterial blockages 5 to 7 inches long. “We’ve had a lot of success treating complete blockages that aren’t severely calcified,” he noted. Now the makers of the SilverHawk, ev3 Endovascular based in Plymouth, Minn., have begun offering the TurboHawk™, which is designed to remove moderately- to severely-calcified lesions in varying vessel diameters. The TurboHawk combines the spinning cutter tool with an improved counter-wound drive shaft that allows for smoother passes with less effort through the calcified plaque.
Wunder described the SilverHawk and TurboHawk as “a lot less brutal” than angioplasty. “You get back to the normal-size artery that you once had,” he said, “and you don’t destroy it in the process.” He noted that angioplasty opens an artery, too, but the balloon “basically rips the artery in a controlled fashion.”
Wunder said there’s “an art and skill” to using the SilverHawk, since the surgeon is looking at the artery and instrument inside it two dimensionally and then operating using that three-dimensional piece of equipment. “You’re trying to make it [the artery] round again, but you can only see two dimensions,” he said.
However, Wunder predicted that advances on the horizon will remedy that problem. Under research and development is the imaging technology necessary to attach a miniscule camera to the device “so we can see the plaque as we cut it. It’s going to become more virtual, like you’re driving a little mining car down that artery,” said Wunder, who has been asked by the manufacturers to help evaluate the instrument’s improvements. “We are involved in those discussions,” he said.
Premier Radiology offers the SilverHawk and TurboHawk procedures on an outpatient basis at its center on Briarville Road in Madison. That facility was the first comprehensive outpatient interventional radiology center in Middle Tennessee.