Abstract and Introduction
Abstract
The most common underlying etiologic factors responsible for chronic delayed healing among lower extremity wounds encountered in the outpatient clinic are chronic venous insufficiency (CVI), diabetic neuropathy, and arterial insufficiency (AI). One or more of these factors can be identified in more than 90% of chronic lower extremity ulcers, and treatment protocols have been designed to manage wounds of each type to maximize healing potential. It is important to remember that multiple factors may coexist in any individual patient with a chronic wound, complicating management and hindering the healing process. Recently, it has been reported that the neuroischemic diabetic foot ulcer is now more common than nonischemic neuropathic diabetic foot ulcers, as arterial insufficiency promoted by poorly controlled diabetes complicates already impaired healing present in patients with diabetes. This article will discuss the management of patients with leg ulcers and both arterial and venous insufficiency, including identification, diagnostic methods, and treatment protocols to maximize the potential for wound healing.
Introduction
Neuroischemic diabetic foot ulcers are now more common than nonischemic neuropathic diabetic foot ulcers, as arterial insufficiency promoted by poorly controlled diabetes complicates already impaired healing present in the diabetic patient.
Arterial insufficiency complicating a patient with a venous leg ulcer (VLU) leads to difficulties in treatment due to the standard protocols for leg ulcers associated with venous hypertension. Obstruction and/or reflux in the venous system, either from a primary or secondary etiology, results in elevated venous pressures in the lower extremity. This venous hypertension must be addressed to eliminate inflammation and allow wound healing to commence. Two general methods are available to eliminate venous hypertension: correction of the underlying venous dysfunction by endovenous ablation, venous stenting or other interventions, or the application of external compression strong enough to eliminate venous hypertension.
The amount of compression required to eliminate venous hypertension and allow venous ulcers to begin to heal remains debatable, but it appears that higher strength compression is better than lower strength compression. In a review of the available literature on compression for CVI ulcers, the Cochrane review found that evidence clearly favored outcomes for strategies employing higher strength compression, which is typically defined as a minimum of 30 mmHg to 40 mmHg of compression at the ankle. In a string of well documented studies, Partsch and colleagues have reported excellent results with higher applied pressures using inelastic compression systems that have the potential to apply higher pressures to the limb while ambulating and lower resting pressures to avoid patient discomfort or other complications. All treatment guidelines for venous ulcers include the use of high-strength compression therapy as mainstays of treatment. The American Venous Forum rated compression a 1B (strong) recommendation for CVI ulcer healing. The Wound Healing Society venous ulcer guidelines advised the use of Class 3 high-compression systems with a Level 1 recommendation.
Patients with significant arterial obstruction in the lower extremity vasculature may not be able to tolerate high strength compression as this may reduce forward flow in the arterial system to the point where the patient experiences severe pain or tissue necrosis. A recent Cochrane review on compression for venous ulcers found that an ABPI < 0.8 was considered an exclusion criterion for compression therapy in 23 of 33 reviewed studies. The Wound Healing Society guidelines state that the degree of compression must be modified when mixed venous/arterial disease is identified during diagnostic work-up, but the level of arterial disease requiring compression reduction and the amount of modification are not defined.