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Therapeutic Strategies

Venous Insufficiency and Venous Ulcers

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Saturday, January 01, 2011

Overview

Stasis dermatitis and ulcers are complications of chronic venous insufficiency. Sixty percent of leg ulcers are due to venous insufficiency, and 30% more are associated with a combination of arterial and venous insufficiency.

Stasis Dermatitis

Stasis dermatitis typically appears above the medial malleolus. It is complicated by xerosis and allergic contact dermatitis in many cases.

First Steps

If available, treatment is with paromomycin sulfate 15% and methylbenzethonium chloride 12% in white soft paraffin applied twice daily for 10 days.

Alternative Steps

  1. Control of edema is mandatory!
    1. Elevate the lower extremity by raising the foot above the level of the heart while the patient is sitting. When possible, encourage lower-extremity muscle-pump activity by having the patient walk; discourage standing, but encourage "toe-risers" when standing is unavoidable.
    2. Employ elastic stockings of at least 30 mmHg to firmly but gently compress the extremity.
  2. Prescribe a medium-potency topical corticosteroid cream twice daily to dermatitic skin. Compression stockings may be worn after steroid application. Expect resolution of dermatitis in 7-14 days.
  3. If cellulitis is present, treat with an appropriate oral antibiotic to cover streptococci and staphylococcus. If the patient fails to respond after 48-72 hours, is febrile, or has an elevated white blood cell count, hospitalize the patient, culture the blood, and treat the patient with intravenous antibiotics to provide coverage for staphylococcal and streptococcal infection.

Subsequent Steps

  1. Continue compression and elevation therapy.
  2. Xerosis and scaling frequently follow dermatitis; apply an emollient regularly as needed.

Control of edema by simple physical measures may not be possible in some individuals. For such patients, consider evaluation for another cause of the persistent edema (cardiac, hepatic, or renal disease).

Pitfalls

  1. Peripheral edema may be caused by mechanisms other than venous insufficiency. Consider congestive heart failure, lymphatic obstruction (cancer), renal failure, or hepatic disease.
  2. Dermatitis may be from contact dermatitis rather than stasis. Patients may have used topical preparations containing lanolin, parabens, ethylenediamine, neomycin, or other sensitizers. An adequate history and appropriate patch testing are keys to confirming this diagnosis.

Venous Insufficiency Ulceration/Stasis Ulcer

Stasis ulcers are the most common cause of leg ulceration. Evidence of venous insufficiency may be minimal, so in some cases vascular evaluation (Doppler) may be required to confirm venous insufficiency as the etiology of the leg ulcer. In all ulcerations, if appropriate and progressive healing does not occur, a biopsy is indicated. Patients with a tendency to lower leg ulcerations may have inherited or acquired defects in their fibrinolytic systems. Appropriate evaluation for these conditions is indicated, especially if there is a history of prior venous thrombosis. Arterial insufficiency may coexist. Determining the ratio of the diastolic blood pressure in the leg vs. the arm (ankle-brachial index, or ABI) is recommended in all patients, as standard methods for healing venous ulcerations may be ineffective in the presence of significant arterial disease (ABI <0.5-0.7).

First Steps

  1. Control edema and dermatitis as described above. Control of edema is essential to improvement of the leg ulcer.
  2. Treat infection: Excessive drainage, surrounding cellulitis, tenderness, and failure of a healing ulcer to continue to heal may be signs of infection. Wound cultures are recommended and appropriate antibiotic therapy should be given. NOTE: All leg ulcers will be colonized with bacteria, so finding bacteria by culture does not diagnose "infection". Cultures of leg ulcers are only of value if they are obtained in the setting of clinical findings of infection. The presence of infection is confirmed if treatment for infection improves the patient's symptoms and the appearance of the ulcer.
  3. Debride the ulcer: If there is firm adherent fibrinous exudate in the ulcer, debridement will accelerate healing. Apply 30% lidocaine in acid mantle base and wait 20 minutes before gently debriding with a curette. This can be repeated at each visit, until all necrotic debris has been removed from the ulcer bed.
  4. Apply a multilayered dressing and change on a weekly basis. A typical dressing would include the following:
    1. Metronidazole to control bacterial overgrowth.
    2. Becaplermin to stimulate granulation tissue (in slowly responding ulcers).
    3. Desiccated animal collagen (xenograft) if needed to accelerate wound healing (in slowly responding ulcers).
    4. Semipermeable dressing over the whole ulceration, sealed at the periphery. For exudative wounds, fenestrated dressings, or superabsorptive ones, may be used.
    5. Unna boot wrap of the whole leg from toes to just below the knee.
    6. Application of Coban dressing to apply appropriate pressure (30 to 40 mmHg). Multilayered elastic dressings may also be used.
  5. On a weekly basis, measure the ulcer (to document improvement), gently clean and debride the ulcer bed and reapply dressings.

Ancillary Steps

  1. If the ulcer is exudative or foul smelling, this is usually due to overgrowth by anaerobic bacteria. Put metronidazole gel 0.75% into the ulcer bed before applying the dressing to control bacterial overgrowth.
  2. Pentoxyphylline 400 mg 3 times daily results in more rapid healing of venous stasis ulceration.
  3. Venous ulcers can be very painful. Usually, the pain resolves once a granulating base is formed. Provide adequate oral analgesia, and monitor the severity of the pain. Often, pain reduction parallels or precedes ulcer healing.

Subsequent Steps

  1. After the ulcer heals, carefully continue the program of edema control. Support hoses with at least 30 mmHg compression are essential for all patients with healed leg ulcers.
  2. If the ulceration fails to heal, cultured human keratinocyte or human skin equivalent grafting can be considered. These grafts are not permanent, but are effective in converting nonhealing leg ulcers into healing ones. They are also very effective in pain control.

Pitfalls

  1. A nonhealing ulcer may be cutaneous carcinoma (basal cell, squamous cell, etc). Biopsy nonhealing ulcerations after 3 months of treatment.
  2. The topical antibiotics bacitracin and especially neomycin should not be applied to leg ulcers due to the high risk for allergic contact dermatitis.
  3. Oral antibiotics are overused in the management of leg ulcers. Many "exudative" ulcers represent appropriate exudation indicative of the early phase of wound healing. This will resolve over a few weeks as the ulcer bed is replaced with granulation tissue.
  4. Any ulceration that is deep and fails to heal, or that develops an undermined "pocket" at one edge, should be evaluated for underlying osteomyelitis with an appropriate radiological study.
  5. If arterial insufficiency coexists (especially ABI <0.7), vascular surgical intervention may be required before the ulcer will heal.
  6. Nonhealing venous insufficiency ulcerations frequently occur after surgeries for skin cancers below the knee in elderly persons. Before surgery in elderly persons, perform an ABI and evaluate the patient for venous insufficiency. If significant venous insufficiency exists, consider wrapping the extremity with a support wrap (as outlined above) during the healing period.
  7. Cholesterol emboli, sickle cell disease, polyarteritis nodosa, Buerger's disease, cocaine use, and antiphospholipid antibody syndrome may all cause lower leg ulcerations. If the ulcer is atypical or fails to heal, consider appropriate evaluation.

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