Blocked Blood Flow Increases Risk of PAD
"PAD is caused by atherosclerosis that narrows and blocks arteries in various critical regions of the body," says Raja Ramaswamy, MD, an interventional radiologist at MIR. It usually occurs after age 50, and is most often seen in the legs.
"Blocked blood flow raises the risk of getting an infection in the affected limbs," Ramaswamy says. In very serious cases it can lead to leg amputation.
Woods was diagnosed with multiple blockages in her superficial femoral artery — the main artery that runs alongside the thigh. Inadequate blood flow caused her leg to ache.
"The most common symptoms of PAD involving the lower extremities are cramping, pain or fatigue in the affected leg or hip muscles when walking or climbing stairs," continues Ramaswamy. "The pain goes away with rest, but returns when you resume walking." This is called claudication and most patients who come to see Ramaswamy and his MIR colleagues present with it. So did Woods.
"Her blood flow was so bad that her leg wasn’t perfusing adequately," he says. It wasn’t flowing down into her leg or foot. "That’s why she was having issues with walking."
Underdiagnosed and Undertreated
Many people mistake PAD for something else. What’s worse, because other conditions share similar symptoms many healthcare professionals underdiagnose it. "The most common test for PAD is the ankle-brachial index (ABI), a painless exam in which ultrasound is used to measure the ratio of blood pressure in the feet and arms," says Ramaswamy. ABI exam results, together with one’s symptoms and risk factors, help determine the diagnosis.
Above: Raja Ramaswamy, MD, in one of the MIR interventional suites at the Center for Advanced Medicine.
PAD risk factors include a history of smoking, diabetes, high blood pressure or high cholesterol, and advanced age. Woods had three of these risk factors: she was 69, and had diabetes and high blood pressure. Peripheral arterial disease can also be diagnosed with a magnetic resonance angiogram (MRA) or computed tomography angiogram (CTA), says Ramaswamy. An MRA or CTA is also a noninvasive study that produces detailed images of the blood vessels, and can be performed in areas of concern.
Although Ramaswamy strongly suspected an arterial problem upon examining Woods, a CTA confirmed it. "He told me 'I'm going to fix that leg for you,'" says Woods. "He was so nice. He made all the difference." Relieved, Woods nonetheless still had reservations. "She asked me if I was going to 'cut her open,' " says Ramaswamy. "I told her 'No,' and that everything we do here is through minimally invasive techniques."
Woods' life dramatically improved when she underwent a new type of balloon angioplasty to open the blocked artery, followed by a stent insertion to keep the artery open.
First-Line Treatment for Arterial Occlusions
Interventional radiology and its minimally invasive imaged-guided procedures are gaining momentum as the treatment of choice for many conditions — including peripheral arterial disease.
"Early randomized trials have shown interventional therapy to be as effective, and with less complications, when compared to surgery for arterial occlusions," says Ramaswamy.
There currently are three options for a minimally invasive image-guided procedure, each with specific patient parameters.
"In an atherectomy, a tiny catheter is inserted into the artery at the site of blockage to 'shave' or 'cut' the plaque from the inside of the artery and remove it," says Ramaswamy. "A stent-graft is a tiny scaffold-like device covered with synthetic fabric that’s inserted into the blood vessels to bypass diseased arteries."
Ramaswamy performed the third option on Woods — an angioplasty and stenting.
"Balloon angioplasty and stenting have generally replaced invasive surgery as the first-line treatment for PAD," says Ramaswamy. Using imaging for guidance, the interventional radiologist threads a catheter through a tiny nick in the femoral artery in the groin to the blocked artery in the legs, then inflates the balloon to open the blood vessel where it is narrowed or blocked.
Ramaswamy used a new drug-coated balloon on Woods. "Once you inflate it, the drug penetrates the walls of the artery and helps the walls of the vessel stay open. It's a relatively new technology and the whole point to it is so that you don’t have to put a metal stent inside the vessel," he says. Metal stents can 'catch' debris, such as fatty deposits of plaque in the bloodstream, and occlude.
To Stent or Not to Stent
The decision to stent or not depends upon the case. Woods’ peripheral arterial disease was compounded by other conditions and severe enough to still warrant a stent. "We put Ms. Woods under moderate sedation with pain and anti-anxiety medication through an IV," says Ramaswamy. "We rarely perform these procedures under general anesthesia."
They accessed the blocked vessel with a catheter through skin and arterial nicks the size of a pencil point. Contrast dye was injected to highlight the targeted vessel. Then the drug-coated balloon was inserted, inflated and removed.
Dye was injected again, immediately after the balloon angioplasty, allowing Ramaswamy to see in real time howthe vessels reacted. Within an hour, Woods' artery was re-opened and all blockages were gone, says Ramaswamy. A precautionary stent was inserted, however.
"The best thing about this (case) is that Ms. Woods is able to walk and do her normal activities again," he says. "We brought her here to one of our interventional suites, did the procedure in an hour, watched her for two hours after the procedure, and then let her go home the same day. It's a very streamlined process as opposed to open surgery, and the patient recovers much quicker."
Left: Raja Ramaswamy, MD, looks at ultrasound images during one of his interventions.