Offloading is key to diabetic foot ulcer management




VANCOUVER – Offloading of plantar pressures is the key component of successful management of plantar diabetic foot ulcers, Dr. Afsaneh Alavi asserted at the World Congress of Dermatology.

“Debridement to remove the callous is the most important part of local wound care, but debridement without offloading afterwards will rebuild callous,” explained Dr. Alavi, a University of Toronto dermatologist.

Dr. Afsaneh Alavi

Many options exist in terms of offloading devices. The total contact cast is recognized as the gold standard. It reduces pressures by 90%. Yet a national survey of more than 900 foot clinics found that less than 2% of centers utilized total contact casts for the majority of their patients with plantar diabetic foot ulcers. Only 15% of centers utilized another highly effective option, the removable cast walker, in the majority of patients (Diabetes Care. 2008 Nov; 31(11): 2118–2119). Cost is believed to be a major issue. Other options include custom orthotic inserts and forefoot and heel relief shoes.

The diabetic foot ulcer recurrence rate is extremely high: up to 83% within the first year.

“Counsel patients to use therapeutic shoes and insoles, engage in self-inspection, and get professional foot care. Shoes should be worn at all times, even in the house. Patients typically spend 30%-40% of their time at home,” Dr. Alavi continued.

The pathophysiology of diabetic foot ulcers is a vicious circle of immunopathy, neuropathy, and angiopathy. Callous formation secondary to sensory and motor neuropathy leads to subcutaneous bleeding, ulcer formation, and deeper infection, sometimes with life- or limb-threatening osteomyelitis.

“Detection of this chain of events at the stage of callous formation would make a huge difference,” according to the dermatologist. She pointed out that “Most of our health care system is focused more on management than prevention. We spend more on amputations due to diabetic foot ulcers than for prevention.”

Although many methods of callous removal are available, including autolytic therapy with hydrogels, whirlpools, and wet-to-dry dressings, Dr. Alavi said the best method is sharp surgical debridement. She highlighted a retrospective 12-week study of topical wound treatments in 310 diabetic foot ulcers and 366 chronic venous leg ulcers which found that venous leg ulcers showed a 34% greater median wound surface area reduction following office visits with surgical debridement compared with no surgical debridement. Serial surgical debridement in patients with diabetic foot ulcers was also associated with a 2.35-fold increased likelihood of wound closure (Wound Repair Regen. 2009 May-June;17(3):306-11).

She noted that it has been estimated that by 2030, at least 10% of the world’s adult population -- some 550 million people -- will have diabetes. And a diabetic individual’s lifetime risk of developing diabetic foot ulcers is up to 25%. The 5-year mortality rate following amputation related to a diabetic foot ulcer is nearly 50%, about the same as following diagnosis of colon cancer.

Dr. Alavi reported serving as a consultant to Acelity and Smith & Nephew.

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