Northwestern Medicine Investigates Using Stem Cells to Save Limbs from Amputation

Northwestern Medicine
Clinical Trials and Research April 02, 2015
Dr. Karen Ho (left) and Dr. Melina Kibbe investigate a potentially breakthrough treatment for those suffering from peripheral artery disease (PAD), a condition affecting 20 percent of Americans where cholesterol and fatty plaque pool in blood vessels, restricting blood flow to the limbs.
After surgery failed to relieve extreme pain caused by peripheral artery disease in her right leg, Denise Hopkins-Glover was facing a bleak outlook — she might never walk again.

“They said they had done everything they could and the only option was amputation of the right leg from the knee down,” she said.

Undeterred, Hopkins-Glover chose to participate in an investigational trial at Northwestern Medicine called the MOBILE Study, which makes use of a device called the MarrowStim™ PAD Kit. In the trial, a randomized group of patients receive injections of their own stem cells retrieved through a bone marrow extraction to try to restore blood flow to the leg.

“MarrowStim offers a new approach for patients with a grim prognosis,” said principal investigator Melina Kibbe, MD, a vascular surgeon at Northwestern Memorial Hospital and Edward G. Elcock Professor of Surgical Research at Northwestern University Feinberg School of Medicine. “We’re pleased to be part of this national trial to see if there might be a significant chance of improving treatment for patients with few choices left for treatment.”

Hopkins-Glover, a 55-year-old grandmother of two, suffers from peripheral artery disease (PAD), a condition affecting 20 percent of Americans where cholesterol and fatty plaque pool in blood vessels, restricting blood flow to the limbs. In its most severe form, PAD causes critical limb ischemia (CLI), which can cause pain in resting legs, sores or ulcers that don’t heal, thickening of the toenails and gangrene, which can eventually lead to amputation.

The Chicago resident worked as a phlebotomist before her PAD worsened, and had to stop working because she could no longer walk or stand for extended stretches of time.

“I can walk only a certain distance before the circulation stops getting to certain parts of the body,” she said. “It feels like a terrible leg cramp, like a jabbing, stabbing pain.”

During the procedure, patients are put under general anesthesia as bone marrow is harvested through a needle from the hip. The bone marrow is loaded into the MarrowStim™ PAD Kit, an investigational device, where it is processed in a centrifuge. This spinning separates the marrow into different layers, with one of the layers containing the stem cells.  Immediately following the separation, the stem cells are injected in 40 different spots on the affected limb, delivering concentrated bone marrow in each one. The entire procedure takes about 90 minutes. Patients follow up with investigators at different intervals in the year following the injections. 

Karen Ho, MD, a Northwestern Medicine vascular surgeon who is also an investigator on the trial, said the exact reason the bone marrow injections might help chronic limb ischemia is still a mystery.

“Nobody really knows the exact mechanism,” said Dr. Ho, who is also an assistant professor in vascular surgery at Feinberg. “The idea is that it might improve or enhance new blood vessels in the calf.”

Dr. Ho said patients that suffer amputation experience not just the loss of a limb but also significant loss of quality of life. Often, though, patients have tried every other available treatment and amputation is the only option left, which is why the MarrowStim™ PAD Kit might offer significant promise.

“There’s a lot of morbidity; people end up with wound healing issues,” Dr. Ho said of amputees. “They suffer from depression, and many find they can’t live at home and end up in nursing homes.”

Three out of four people in the MOBILE study group receive the stem cell injections. Hopkins-Glover does not know if she was part of that group or if she received a placebo.

She said she dreams of regaining the active life she once lived.

“I just want to go to the park, the zoo, just walk around the neighborhood,” Hopkins-Glover said. “Even if I didn’t get the stem cells this is helping me to psychologically motivate. If it doesn’t help me maybe it will help someone else.”

To learn more information about the MOBILE Study at Northwestern, call 312.926.4801.

To learn more about Northwestern’s Center for Vascular Disease, part of the Bluhm Cardiovascular Institute, or call 312.NM.HEART.
Northwestern Medicine’s cardiology and heart surgery program, the Bluhm Cardiovascular Institute, ranked 13th nationally in the 2014-15 U.S. News & World Report “Best Hospitals” list released in July 2014. For the seventh consecutive year, the report ranked BCVI the top heart program in Chicago, Illinois and the Midwest. 

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