by Michael Richman, MD, FACS and Dorrie Emrick, RN
Venous disease occurs when a vein is not functioning properly causing a disturbance of normal one-way blood flow, usually causing venous insufficiency. When encountering a patient with a venous leg ulcer, you must first determine the cause. This begins with a history, physical examination and an ultrasound which provides detailed information about the venous system and will show sites where the reflux is occurring.
Most venous ulcers occur just above the ankle. It is important to remember that some patients with venous disease also have arterial disease which may hamper healing of the venous ulcer. A quick way to determine if significant arterial disease is present is to perform ankle-brachial indices in the office.
Clinically significant arterial disease is defined using a cut-off of the ABI of below 0.8. This may influence the need for further testing and influence the type of treatment for the venous ulceration.
Compression stockings are a mainstay in the treatment of venous ulcers caused by venous insufficiency. This is especially important in that venous ulcers represent the vast majority (80% to 85%) of all leg ulcers. (Moffatt, et al 2009). As stated in the Cochrane Review, the history of compression stockings, span from the 17th Century when they were applied as stiff lace-up stockings to the invention of elastic bandages in the middle of the 19th Century.
Treatment is ever evolving, however the current US gold standard of care continues to be the Unna Boot, which was developed by German dermatologist, Dr. Paul Gerson Unna in the late 1800s.
The Unna Boot
The Unna Boot is effective in that it places a firm pressure on the calf muscle in an ambulatory patient. This pressure is a priority in improving the venous return and decreasing associated edema, which facilitates the healing process. The boot may improve cutaneous and subcutaneous microcirculation in a manner similar to performing vein surgery to alleviate the reflux causing the ulcer (Bergan 2000). It is important to note that if the primary cause of the ulcer is not addressed, long term healing will be compromised.
The boot has a firm plastic-like consistency that is made of calamine and zinc oxide which has been proven to promote wound healing and is anti-bacterial. In order to apply the boot you must first dorsiflex the patient’s foot and wrap the medicated bandage firmly making sure to fully cover the heel, then continue wrapping upward overlapping 50% each to below the knee. It is of most importance that the boot be applied by a skilled and trained clinician as the application determines the effectiveness.
The components of the boot are for single use and should stay in place for one to two weeks. We wrap an ace bandage over the boot to keep it clean and dry.
The 3M Coban Two-Layer Compression System
The inability to self-apply and remove the Unna Boot may cause non-compliance. A new research study conducted by Dr. Giovanni Mosti, MD et al compared the Unna Boot to a new two-component compression system 3M Coban Two-Layer Compression System that is more user friendly. This new bandage includes two short stretch systems - one inner layer of foam and one outer compression layer that is a cohesive bandage. 100% of study participants agreed it was “very easy” to apply and remove the 3M Coban compared to the Unna Boot.
The median healing time for the 3M Coban Two-Layer Compression System was 49.5 days (compared to Unna Boot of 48 days) with effective pain control and elimination of leg edema. There was also no incidence of itching or sensation of tightness in the 3M Coban. (Mosti et al 2011). Overall this proves to be an effective option when application of therapy in healing venous ulcers is an issue.
The Coban 3M Two-Layer Compression System and the Unna Boot prove to both be effective in the treatment of venous ulcers. The downside is that both are stiff products and patients may resist usage. When patient compliance becomes an issue-you may recommend compression stockings; in our practice we use 30-40 mm Hg thigh high stockings and localized wound care.
This often facilitates the need for daily visits to a wound center or a home nursing visit for dressing changes. It is of utmost importance that patients are educated in order to fully manage ulcers. One must continue to wear compression stockings. It has been reported that some people believe that compression therapy will worsen their ulcer, therefore it is essential that you provide correct information to the patient.
Patient Education on the 3M Coban Compression System
Annells et al discusses the importance of having a nurse specialist educate the patient that compression therapy is the best practice, even creating community based ‘leg clubs.’ Building trust is a necessity and it is important not to rely on written information. Being knowledgeable about compression requires understanding the principles and theory of compression bandaging and competent application skill.
Studies have shown that patient barriers include pain, skin irritation, difficulty in applying compression, unesthethetic bandages, implications for foot wear and the impact on mobility and social isolation.
Compression systems in lieu of surgery are a necessity in the management of venous ulcer wounds. The favored choice is the Unna Boot or similar bandage, such as the 3M Coban Two-Layer Compression System which provides consistent pressure on the calf muscle. When patient compliance becomes an issue-some compression is better than none; a solid choice is a 30-40 mmHg thigh high stocking.