Well’s Criteria for DVT

The Score

1. Active cancer (treatment within last 6 months or palliative) -- 1 point
2. Calf swelling >3 cm compared to other calf (measured 10 cm below tibial tuberosity) -- 1 point
3. Collateral superficial veins (non-varicose) -- 1 point
4. Pitting edema (confined to symptomatic leg) -- 1 point
5. Swelling of entire leg - 1 point
6. Localized pain along distribution of deep venous system—1 point
7. Paralysis, paresis, or recent cast immobilization of lower extremities—1 point
8. Recently bedridden > 3 days, or major surgery requiring regional or general anesthetic in past 4 weeks—1 point
9. Alternative diagnosis at least as likely—Subtract 2 points

Possible score -2 to 8

Interpretation

Score of 2 or higher - deep vein thrombosis is likely. Consider imaging the leg veins.
Score of less than 2 - deep vein thrombosis is unlikely. Consider blood test such as d-dimer test to further rule out deep vein thrombosis.

References

• http://en.wikipedia.org/wiki/Deep_vein_thrombosis
• http://emedicine.medscape.com/article/758140-overview
  

Lipodermatosclerosis (LDS)

• LDS literally means "scarring of the skin and fat" and is a slow process that occurs over a number of years.
• Occurs in patients with long-standing venous disease resulting in chronic venous insufficiency.
• Affects the skin just above the ankle, usually on the inside surface.
  
• Over time the skin becomes brown, smooth, tight and often painful.
  
• The precise mechanism of LDS is not fully understood, but we do know that it is caused by an excessively high venous pressure in the subcutaneous veins in the lower leg.

References:

• http://www.simondodds.com/Venous/LDS.htm
• http://www.bu.edu/woundbiotech/wounds/UncommonWounds%20Gallery/pages/19..htm
  

Chronic Venous Insufficiency (CVI)

Symptoms

• Varicose veins
• Ulceration or skin breakdown
• Lipodermatosclerosis
  
• Reddened or discolored skin on the leg
• Oedema

Risk factors

• Heredity
• Obesity
• Pregnancy
• Sedentary lifestyle
• Smoking
• Jobs requiring long periods of standing or sitting in one place
• Age and sex (women in their 50s are more prone to developing CVI)
• Incompetent valves
• previous DVT

Pathophysiology

• Increased venous pressure transcends the venules to the capillaries, impeding flow.
  

• Low-flow states within the capillaries cause leukocyte trapping.

• Trapped leukocytes release proteolytic enzymes and oxygen free radicals, which damage capillary basement membranes.

• Plasma proteins,such as fibrinogen, leak into the surrounding tissues, forming a fibrin cuff.
  

• Interstitial fibrin and resultant oedema decrease oxygen delivery to the tissues, resulting in local hypoxia.
  

• Inflammation and tissue loss result. Ulceration may occur.
  

Management

• Leg elevation
  
• Elastic compression therapy - especially with older patients you need to ensure they are actually able to put the compression stockings on for themselves.
  
• Sclerotherapy - chemically scarring the veins from the inside out so that they can then no longer fill with blood. Blood that would normally return to the heart through these veins returns to the heart through others. The body eventually absorbs the veins that received the injection.
• Vein stripping
• Deep vein surgery - note that surgical treatment is reserved for those with discomfort or ulcers refractory to medical management.
• Valve repair

Ankle-Brachial Index

The Ankle – Brachial Index (ABI) is a ratio of the systolic blood pressure measured simultaneously in the leg and arm. This test is done to screen for peripheral arterial disease (PAD) of the legs.

What the values mean:

• An ABI ratio less than 0.8 implies significant arterial obstruction.
• A ratio of 0.5 or less implies critical obstruction.
• A ratio of < 0.3 implies impending gangrene.
  

Patients with PAD should not wear compression stockings due to high risk of ischaemia.

References:

• Ankle-brachial index test, WebMD
  
• Facts about Intermittent Claudication, North Suburban Cardiology Group