Venous and Lymphatic Disorders
Acute venous thromboembolism
Use the Wells score to guide testing: low or intermediate probability with a negative D-dimer excludes DVT (age-adjust the threshold above age 50). Duplex shows loss of compressibility, absent phasicity, and failure to augment. Anticoagulate for three months after provoked events, longer for unprovoked, recurrent, or cancer-associated thrombosis. Catheter-directed thrombolysis with stenting is reserved for iliofemoral thrombosis with limb threat (phlegmasia cerulea dolens) or May-Thurner anatomy, where the left common iliac vein is compressed by the right common iliac artery. Place IVC filters only when anticoagulation is contraindicated, and retrieve them when feasible.
Chronic venous disease
CEAP classifies disease from C0 to C6. Reflux is defined as over 0.5 seconds in superficial and over 1 second in deep veins. Saphenous incompetence is treated with endovenous ablation or stripping; intervention is inappropriate when the deep system is occluded. Venous ulcers sit near the medial malleolus with sloping edges, and compression is the mainstay - but check the ABI first. Compression is generally safe above 0.8, modified between 0.6 and 0.8, and avoided below 0.6. Early mobilization and elastic compression reduce post-thrombotic syndrome.
Lymphedema and upper limb
Lymphedema is non-pitting, involves the dorsum of the toes (Stemmer sign), and is managed with complex decongestive therapy. Paget-Schroetter effort thrombosis in an overhead athlete is treated with thrombolysis and thoracic outlet decompression. Superficial thrombophlebitis longer than 5 cm merits prophylactic anticoagulation.
Rule of thumb: before you wrap a leg ulcer, measure the ABI - compression is a drug with a contraindication.