Feasibility Study of Cryotherapy for Chronic Venous Disorders

Chronic venous disorders (CVDs) often cause long-term disability for those who experience the worst manifestations of CVDs: disabling pain and non-healing leg ulcers. Such disabilities have significant socioeconomic implications in terms of lost work days and wages, decreased productivity,and ultimately increased health care costs that deteriorate the well-being and quality of life for those who have CVD-induced illnesses. Because no reliable preventive mechanisms exists for CVDs, this study proposes a preventive, self-management cryotherapy intervention that targets inflamed skin of populations with CVDs at highest risk of developing chronic leg ulcers. The proposed cryotherapy intervention will utilize a randomized controlled clinical trial to develop a method to reduce clinical symptoms by improving existing therapy - it is not a treatment for CVDs itself. In the proposed pilot feasibility study, subjects will be randomized to two groups; the cryotherapy intervention group (n=30) who will receive a four-week, cryotherapy gel wrap applied daily to the affected skin of the lower legs in addition to the standard of care (usual care). The control group (n=30) will receive the usual care of compression wraps or stockings applied to the lower legs and daily leg elevation. With this method, improvement of skin microcirculation, reduced leg pain, and improvement in quality of life will be observed. The following aims will test the hypothesis:

Aim 1: Evaluate the feasibility of the novel intervention including treatment fidelity, subject training, safety, and side effects associated with equipment and recruitment efforts and further refine the intervention protocol, including questionnaires used in our previous studies.

Aim 2: Estimate variability of outcome measurements and effect sizes needed to calculate sample size for a subsequent larger, adequately powered, randomized clinical trial of the efficacy of the novel cryotherapy intervention.

Aim 3: Investigate the presence of a preliminary "signal" of clinical efficacy of the experimental treatment by evaluating trends toward statistical significance for the hypothesis that the experimental group will experience greater reduction in skin temperature and blood flow, greater improvement in pain, and greater improvement in quality of life.

Inclusion criteria

• Aged 45 years and older
• CEAP classification: stage C4 (changes in skin and subcutaneous tissue secondary to CVDs)4a (pigmentation or eczema) 4b (lipodermatosclerosis or atrophie blanche) C5 (healed venous ulcers)
• Ankle brachial index (ABI) 0.9 - 1.3mm Hg 0 absence of peripheral arterial disease
• Intact skin sensation measured with 10 gram monofilament
• Intact thermal sensation measured with thermal sensory tester at lower leg skin and foot surfaces
• Agreement to wear compression garments such as wraps or stockings during waking hours
• Phone, e-mail, or mail accessible
• Working freezer

Exclusion criteria

• ABI < 0.8 mm Hg or > 1.3 mm Hg -presence of lower extremity arterial disease (reduces skin temperature)
• Active systemic or localized infections such as cellulitis (raises skin temperature)
• Autoimmune disorders that reduce blood flow such as Raynaud's phenomenon
• Body temperature > 37.6 degrees C (febrile state raises skin temperature)
• CEAP classification c6: active venous ulcer (cooling ulcerated skin might impair healing)
• Known peroneal nerve injury
• Impaired skin sensation
• Unable to detect light touch measured with a 10 gram monofilament at lower leg skin surfaces
• Unable to detect not/cold sensation measured with thermal sensory tester at lower leg skin surfaces
• Not wearing compression or not agreeing to wear compression wraps or stockings
• Phone, e-mail, or mail inaccessible
• No working freezer