Stem Cell Therapy Treats CLI

Patients with severe critical limb ischemia (CLI) have an exciting new treatment option – autologous stem cell therapy. Karl Stark, MD, FACS, with Kansas City Vascular, PC, is currently running two clinical trials with "incredible results," he says.

Stem Cell"This new stem cell therapy is a game changer for patients at high risk for losing a limb and for whom nothing else works," says Dr. Stark. "We have been looking for a viable treatment for a long time, and these new trials show the greatest promise." He has been involved in four clinical trials. The first two involved IV infusion of prostaglandins and the second was hyperbaric oxygen therapy but the results were not as profound as what his patients are experiencing with the two current stem cell trials.

Severity of CLI

CLI is the most severe form of peripheral artery disease. It’s differentiated from acute limb ischemia in the duration of the process and the underlying etiology. Acute limb ischemia is usually embolic or thrombotic occlusion of the arteries of the leg.

Of patients with CLI, 25% will die within one year; 40% within 5 years. The one-year amputation rate is 25%, with the mortality risk 5-10% for BKA and 10-15% for AKA. In addition, quality of life and the ability to live independently decrease with an amputation.


Surgical revascularization involves using bovine carotid artery conduit when autologous vein is not available for bypass. It restores blood flow to the affected limb, and gives patients a better chance of survival than amputation. The same holds true for CLI patients, Dr. Stark reports.

Nondirect revascularization treatment options for patients with no reconstructable arteries include hyperbaric oxygen therapy. Clinical trial results  included higher limb salvage rates and lower mortality rates. Patients were also twice as likely to heal their ischemic wounds.

Stark ChartSurvival of patient with CLI and non-reconstructable arterial disease

Evolution of Cell Therapy

For a specific group of patients, cell therapy appeared to be an option when other modalities proved inadequate or not possible: 

  • Arterial reconstruction
  • Compression devices 
  • Infusion of prostaglandins 
  • Sympathectomy 
  • Spinal cord stimulation 
  • Vasodilators

The goal of cell therapy is angiogenesis. In Dr. Stark’s clinical trials, adult or autologous stem cells are used, which are harvested from bone marrow. Differentiated centrifugation separates cells into subgroups and then further separates them into tissue specific-types . An intra-arterial and/or intramuscular injection protocol then deposits cells in the neurovascular bundle.

Lifecells has developed the protocol Dr. Stark is using for harvesting and selecting the most effective stem cells. And  because the work is with autologous stem cells, the process is safer, avoids moral issues and has fewer complications.


It takes 4 to 6 weeks to see results. Since limbs must be healthy enough to withstand this time period, seeing patients early in their disease is important. Early results show improved limb salvage rates at 60%. There is also improved limb perfusion as measured by ankle brachial index and TC02. Interim data also show improvement in ischemic rest pain and ulcer healing.

"We are seeing a lot of interest from around the country in our stem cell clinical trials," Dr. Stark noted. "North Kansas City Hospital is at the forefront of this research, and it’s an honor to work with referrals from some of the leading vascular surgery centers."

Dr. Stark’s presentation

Dr. Karl Stark, MD, FACS

Karl StarkDr. Stark earned his medical degree from the University of Missouri-Kansas City. He completed his residency in general surgery at Truman Medical Center and a fellowship in vascular surgery at Middlesex General University Hospital, New Jersey. Dr. Stark is the Midwest medical director for Healogics and director of the Wound Healing Center at North Kansas City Hospital.

To learn more call, 816.872.1598.