September 2012

Study: Long-Term Survival Of DFU Patients Is Poor

By Brian McCurdy, Senior Editor

A new study in Diabetes Care notes that despite favorable results in long-term limb salvage for patients with diabetic foot ulcers, long-term survival rates remain unfavorable with peripheral arterial disease (PAD) and renal insufficiency making for an especially poor prognosis.

   Researchers focused on 247 patients with diabetic foot ulcers without previous major amputation who consecutively presented to a single diabetes center between June 1998 and December 1999.

   The study authors note that during follow-up, a first major amputation occurred in 38 patients (15.4 percent), 51.4 percent of whom had severe PAD. Age and PAD were significant predictors for first major amputation, according to the study. Furthermore, the authors note that cumulative mortalities at one, three, five and 10 years were 15.4, 33.1, 45.8 and 70.4 percent respectively.

   Study co-author David G. Armstrong, DPM, PhD, MD, notes evidence that modifying certain risk factors early on can reduce the progression of vascular disease in general and also potentially reduce the risk of PAD. Desmond Bell, DPM, says smoking cessation would be the most vital step to prevention. For those who require invasive intervention, lower extremity bypass surgery and endovascular procedures, such as angioplasty, atherectomy and stenting, “are having a profound impact on limb preservation,” notes Dr. Bell.

   “In my opinion, one of the real issues patients are facing is that PAD is under-diagnosed and under-recognized among practitioners,” says Dr. Bell, the Co-Founder and Executive Director of the Save a Leg, Save a Life Foundation in Jacksonville, Fla. “If more providers were aware of the five-year mortality rate associated with PAD, which is approximately 64 percent, I believe we would see a greater sense of urgency surrounding PAD.”

   By way of comparison, Dr. Bell cites the five-year mortality rates of prostate cancer at 9 percent and breast cancer at 14 to 18 percent. “One has to wonder why there is such a general lack of recognition of (PAD),” notes Dr. Bell.

   “We’ve seen now in this study and in others that mortality for people with wounds — and especially for people with wounds, vascular disease and other end-stage complications of diabetes — is at least as bad as a bad form of cancer, well over 50 percent at five years or even worse than that,” says Dr. Armstrong, the Director of the Southern Arizona Limb Salvage Alliance (SALSA).

   Dr. Bell calls for greater screening of those who are at high risk for PAD, especially when considering the link among PAD, heart attack and stroke. Similarly, Dr. Armstrong advises talking to patients and emphasizing aggressive risk factor modification and patient appropriate treatment.

   Dr. Bell also suggests a “major public awareness campaign” to make the public and primary care providers aware that that PAD is likely present in patients in diabetes. As he points out, most of the general population have never heard of PAD, let alone know that September is PAD awareness month.

   Dr. Armstrong stresses the importance of the interdisciplinary team and SALSA’s “toe and flow” philosophy.

   “We believe now that since more than half of our patients have wounds that we would now classify as neuroischemic … that these two specialties, those interested in the toe and those that are interested in the flow, get together — really get together — to make a difference,” adds Dr. Armstrong.

CMS Offers Limited Coverage For PRP Treatment Of Chronic Wounds

By Danielle Chicano, Editorial Associate

The Centers for Medicare and Medicaid Services (CMS) recently announced that it will now cover treatment with autologous platelet-rich plasma (PRP) gel for patients with chronic, non-healing, diabetic, pressure and venous wounds who are enrolled in CMS-approved clinical studies.

   The ruling came after a request from Cytomedix earlier in the year to cover its PRP product, AutoloGel.

   Kazu Suzuki, DPM, CWS, notes that he is intrigued by the CMS ruling and recalls similar PRP products throughout the years.

   Dr. Suzuki notes the trend in orthopedic settings to use autologous PRP injections, “especially within sports medicine, where the treatment cost can be overlooked” because these patients are willing to pay out of pocket for it.

   In addition to the lack of reimbursement associated with PRP gel, prior to the CMS ruling, Dr. Suzuki was unaware of any convincing clinical evidence to show its efficacy specific to wound care, which fueled his decision to use cell-based therapy over PRP products.

   “Even though several times I was offered a chance to try out various PRP centrifuge systems for the treatment of chronic wound care, I have always passed up the opportunity and used clinically proven cell therapy products such as Apligraf (Organogenesis) and Dermagraft (Advanced BioHealing),” explains Dr. Suzuki, the Medical Director of the Tower Wound Care Center at the Cedars-Sinai Medical Towers in Los Angeles.

   Although he welcomes any additions to his treatment armamentarium for chronic wound care, Dr. Suzuki hopes clinicians will use caution when adopting new modalities, such as PRP gel.

   “We don’t have enough randomized, controlled trial data at this time to say PRP treatment is the best treatment for chronic wound care or better than the various cell therapies and extracellular matrix products that have existed for many years,” says Dr. Suzuki.

Is MRI The Best Imaging Modality For The Diabetic Foot?

By Brian McCurdy, Senior Editor

A new study in the European Journal of Radiology notes that magnetic resonance imaging (MRI) is highly accurate in evaluating the bone derangements that occur in the diabetic foot.

   Researchers evaluated 90 feet in 85 patients with radiographs and MRI. The inclusion criteria were clinical diagnosis of diabetes and bone changes on radiographs and MRI. Of the 90 feet, the study notes 17 presented with vascular changes, of which 11 feet had infarct and six feet had necrosis. Twenty feet had traumatic changes, 10 of which had edema on MRI. Five feet had occult fracture on MRI and five had visible fractures on both X-ray and MRI, notes the study. In addition, bone destruction was present in eight feet and bony debris was visible in three of them. Bone dislocation was visible in 11 feet while 24 feet had evidence of osteochondritis, according to the study. Researchers diagnosed osteomyelitis in 10 feet.

   Michelle Butterworth, DPM, says the literature does confirm that overall, MRI is the most specific imaging modality for infection. She will use MRI for preoperative planning to help identify the extent of an infection. Dr. Butterworth says MRI shows the anatomy very clearly and it is relatively easy to distinguish between soft tissue and bone infection. In comparison, she has found bone scans are very sensitive but non-specific for infection.

   “They are simply markers for metabolic activity so they will light up for any inflammatory response, not just infection,” she notes.

   Imaging the diabetic foot does become more complicated, particularly when trying to distinguish Charcot arthropathy from osteomyelitis, says Dr. Butterworth, the President of the American College of Foot and Ankle Surgeons. In such cases, although she feels MRI is still superior to bone scans, even the white blood cell tagged scans, bone biopsy is still the gold standard for diagnosis of osteomyelitis.

In Brief

Healthpoint Biotherapeutics announces that the results of its Phase 2b clinical trial investigating the efficacy of HP802-247 in venous leg ulcers will be published this month in The Lancet. The company notes HP802-247 is an investigational allogeneic living cell bioformulation containing keratinocytes and fibroblasts, and is under development for the treatment of venous leg ulcers.

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