Chronic Leg Ulcer - Causes, Types, Diagnosis, and Treatment

Introduction:

A chronic lower leg ulcer is a common condition among adults, causing pain and social distress. A chronic leg ulcer is defined as a defect in the skin below the knee level for more than six weeks and shows no healing even after three months. There are various factors leading to lower leg ulceration. Hence, an interdisciplinary health professional's approach to the systematic assessment of the pathogenesis, diagnosis, and treatment is required.

What Causes Leg Ulcers?

Leg ulcers can be caused by various factors,

• Vascular disturbances in the veins, arteries ,or both.

• Neuropathic disorders such as diabetes, tabes, and syringomyelia.

• Metabolic disorders like diabetes, gout, and prolidase deficiency.

• Blood disorders like sickle cell disease, or cryoglobulinemia.

• Trauma caused by pressure, injury ,or burns.

• Cancerous growth like Basal cell carcinoma or squamous cell carcinoma.

• Any bacterial, fungal, or protozoan infection.

• Pyoderma gangrenosum.

• Special cases like hypertensive ulcers.

What Are the Types of Chronic Venous Ulcers?

Common lower extremity ulcers are:

Venous Ulcer:

Venous ulcers occur under any of the following conditions:

1. Venous circulation of the lower extremities flows from the superficial to deep veins reaching the inferior vena cava, valves to ensure unidirectional blood flow. Alteration in these pathways leads to venous insufficiency and ulcer.

2. Valvular incompetence occurs when the valves cannot close properly, resulting in increased blood flow and leakage of fluid into the tissue. This leads to the deposition of a brownish or red pigment in the leg's gaiter (above the ankle to below the knee) area.

3. Calf muscle pump failure also leads to venous ulcers. When the calf muscle fails to contract and relax, the blood flow back to the heart through the veins is altered, causing blood stasis and increased venous pressure. It happens in paralysis, immobility, sleeping in a chair with legs down for a long time, and fixed ankle joints.

Venous ulcers are superficial, painful ulcers over bony prominences, particularly the gaiter area (above the ankle to below the knee); swelling, varicosities, venous dermatitis, and lipodermatosclerosis. It persists from weeks to months. Venous ulcers are the most common ulcer which mainly affects women more than men and is common in elders.

Arterial Ulcer:

Arterial ulcer occurs when the artery occlusion decreases blood flow and tissue perfusion leading to an ulcer. It is associated with cardiac or cerebrovascular disease.

Arterial ulcers are yellow, round, or punched out well defined deep over bony prominences exposing the tendons. Patients may present with pain in the thigh, calf, or buttocks when walking, impotence, and pain in the distal foot. Associated findings include abnormal led pulses, relaxed limbs, and increased venous filling time.

Neuropathic Ulcer:

Neuropathic ulcers are the most common foot ulcers usually occurring as a result of diabetes mellitus. Ulcers develop primarily due to trauma or prolonged pressure. Hyperglycemia acts secondary to neuropathy impairment of sensory, motor, and autonomic function, usually in the hand and foot, or "stocking and glove" distributions.

Clinically neuropathic ulcers usually occur on the bottom of feet in patients with diabetes, neurologic disorders, or Hansen disease.

Pressure Ulcer:

Pressure ulcers are commonly seen in patients with limited mobility. The areas under prolonged constant pressure cause decreased blood supply leading to tissue death. Pressure ulcers are clinically located over bony prominences, and their risk factors include excessive moisture and altered mental status.

What Are the Investigations of Chronic Venous Ulcers?

1. Clinical Examination - The ulcer examination includes site, size, appearance, wound base, exudate level, and surrounding skin.

2. The Ankle Brachial Pressure Index (ABPI) - a handheld Doppler ultrasound and sphygmomanometer can be carried out to assess arterial perfusion accurately. When detailed anatomic information is needed, magnetic resonance angiography, computer tomographic angiography, or digital subtraction angiography is obtained.

3. Blood investigations include complete blood count (CBC), erythrocyte sedimentation rate (ESR), lipid profile, blood sugar, renal function tests, and liver function tests.

4. Radiographs - A plain radiography and CT and MRI of the foot to rule out osteomyelitis and malignancy.

5. Laboratory Screening Tests - Urine analysis for proteinuria, cylindruria, hematuria, routine and immunohistopathology of skin biopsies, antinuclear antibodies, rheumatoid factor, complement C4, circulating immune complexes, paraproteins, immunoglobulin fractions, antineutrophil cytoplasmic antibodies, serological tests, and cultures for underlying infections.

6. Laboratory Screening Tests for Clotting Disorders- thrombin time, prothrombin time (PT), activated partial thromboplastin time (APTT).

7. Venography to investigate prior valvular surgery. Lower extremities arteriography in patients with ischemic rest pain, impending gangrene, intolerable claudication, or the presence of non-healing ulcers of suspected arterial origin.

8. Color duplex ultrasound scanning to evaluate venous obstruction in venous ulcers.

9. Plethysmography and venous pressure data - for surgical bypass or valve replacement.

10. A quantitative bacterial culture when wound infection is suspected. A biopsy is also taken for experimental protocols: (A) to obtain details of the wound bed or edge. (B) In vitro culturing from the non-healing wound.

11. The Leg Ulcer Measurement Tool (LUMT) is used to validate leg ulcers and track wound changes over time.

How Is Chronic Venous Ulcer Treated?

The treatment of chronic leg ulcers presents a therapeutic challenge. The basic principles of treatment are as follows:

• Remove or treat the precipitating caused by surgical intervention to enhance circulation and improve venous return or compression therapy to promote healing.

• Wound care is a mainstay.

• Lifestyle changes have to be adopted.

• Symptomatic management of the ulcer can relieve pain and discomfort.

• Promote preventative care.

• Health education should be given to the patient.

• Current treatments for CLU include surgery, sclerotherapy, conventional therapy, and adjuvant pharmacotherapy.

  • Neurovascular interventions include lumbar sympathectomy or spinal cord stimulation.

  • Systemic therapy with Hyperbaric oxygen.

  • Intravenous therapy with Prostaglandins.

  • Local mechanical therapy with negative pressure wound therapy (NPWT).

• Localized oxygen therapy, topical application of growth factors ,or tissue-engineered skin products can enhance the healing process.

Recent advances in management include:

• miRNAs to regulate wound healing.

• The activation or inhibition of integrin receptors may provide excellent wound healing.

• Allogeneic neonatal keratinocytes and fibroblasts spray.

• Stem cell regenerative medicine promotes skin regeneration.

• A natural latex biomembrane extracted from Hevea brasiliensis as a dressing for hypersensitivity patients.

• The topical application of peptides helps in diabetic wound closure.

Conclusions:

Chronic leg ulcers are a result of venous insufficiency and arterial ulcers. Managing patients with chronic ulcers has to be multidisciplinary and should include a detailed history, physical examination, investigations, basic and newer treatment modalities, and educating patients on issues of correct foot care and the importance of seeking early medical advice.