Graduated compression therapy for chronic venous insufficiency — from CEAP classification to venous ulcer healing
Chronic venous insufficiency (CVI) encompasses a spectrum of disease, from asymptomatic thread veins to non-healing ulceration. The CEAP classification (Clinical-Etiology-Anatomy-Pathophysiology), first adopted in 1994 and revised in 2020, gives clinicians a standardized vocabulary to describe severity, guide compression therapy selection, and compare outcomes across studies. The "C" (clinical) component, graded C0 through C6, is the axis most relevant to everyday management and is used throughout this simulator.
C0 — No visible or palpable signs of venous disease. C1 — Telangiectasia (spider veins, <1mm) or reticular veins (1–3mm). C2 — Varicose veins: dilated, tortuous superficial veins ≥3mm. C3 — Edema attributable to venous disease, typically worse by end of day. C4 — Skin changes: C4a pigmentation/eczema (hemosiderin staining from red-cell breakdown) or C4b lipodermatosclerosis/atrophie blanche (subcutaneous fibrosis). C5 — Healed venous ulcer. C6 — Active venous ulcer, the end stage of untreated venous hypertension.
Each class also carries an etiology (congenital, primary, secondary, or no venous cause identified), an anatomic descriptor (superficial, deep, or perforator veins), and a pathophysiology descriptor (reflux, obstruction, or both) — together forming the full CEAP score used in vascular clinics.
CEAP class is the single most important input for selecting compression strength. Mild disease (C1–C2) is managed with lower-pressure hosiery for symptom relief and cosmesis; moderate disease with edema (C3) or early skin change (C4) requires stronger graduated compression to control fluid accumulation and halt the inflammatory cascade that leads to lipodermatosclerosis; severe disease with healed or active ulceration (C5–C6) requires the highest tolerated compression, often as multi-layer bandaging in the acute phase, transitioning to a maintenance stocking once the wound closes. Reassessing CEAP class at each visit — not just measuring ankle circumference — keeps compression prescriptions matched to the true severity of the underlying venous hypertension.
Every visible sign of CVI, from a spider vein to an open ulcer, traces back to one physiological problem: ambulatory venous pressure (AVP) that fails to fall normally during walking. In a healthy leg, competent one-way valves and the calf muscle pump propel blood upward with each step, dropping AVP from a resting ~90 mmHg to below 30 mmHg. When valves fail, blood refluxes backward, AVP stays chronically elevated, and that pressure is transmitted directly to the capillary bed.
Venous valves are bicuspid folds of endothelium that permit flow only toward the heart. Reflux — retrograde flow lasting longer than 0.5 seconds on duplex ultrasound — occurs when valve cusps fail to coapt, whether from primary structural weakness, post-thrombotic scarring, or simple dilation of the vein wall that pulls the cusps apart. Once one valve fails, the column of refluxing blood adds hydrostatic load to the valve below, causing sequential failure down the leg — a self-propagating process that explains why untreated CVI tends to worsen over years rather than remain static.
Sustained ambulatory venous hypertension is transmitted to the postcapillary venules and capillary bed of the skin and subcutis. This drives fluid, fibrinogen, and red blood cells out of the capillaries into the interstitium — producing the edema of C3 disease. Extravasated red cells break down and deposit hemosiderin, causing the brown pigmentation of C4a. Chronic perivascular fibrin cuffing and leukocyte trapping impair oxygen diffusion to the skin, producing the woody induration of lipodermatosclerosis (C4b). Eventually, minor trauma to this fragile, poorly oxygenated tissue — often near the medial malleolus, the site of the highest perforator pressure — fails to heal and becomes a venous ulcer (C6).
The medial malleolus is the classic site for venous ulcers because it overlies the perforating veins with the greatest hydrostatic pressure exposure and the thinnest overlying soft tissue — the combination of maximal pressure and minimal cushioning makes it the weakest point in the system.
Graduated compression stockings apply their highest pressure at the ankle and taper to roughly 40% of that pressure at the thigh, mimicking the natural pressure gradient of upright venous flow and mechanically opposing reflux. Selecting the correct compression class — not simply "the tightest stocking available" — is central to both efficacy and patient adherence, since over-prescribing pressure a patient cannot tolerate leads to non-compliance and, in arterial disease, to tissue injury.
1. Confirm arterial sufficiency first — measure ankle-brachial index (ABI); compression is contraindicated or requires modification if ABI <0.8 (relative caution) or <0.5 (contraindicated). 2. Assign CEAP class from clinical exam ± duplex ultrasound reflux mapping. 3. Match compression class to severity: 15–20 mmHg for C1–C2 symptom control; 20–30 mmHg for C3 edema or C4 skin change; 30–40 mmHg for C5–C6 or recurrent ulceration, starting as inelastic multi-layer bandaging while the wound is open. 4. Choose the delivery format: below-knee stockings suffice for most isolated superficial disease; multi-layer bandaging (e.g., a four-layer system combining orthopedic wool, crepe, elastic, and cohesive layers) is preferred for active ulcers because it accommodates changing limb volume and provides sustained pressure for up to a week between changes. 5. Reassess and step down: once an ulcer heals (C6→C5), transition from bandaging to a maintenance stocking, generally 20–30 mmHg or the highest class the patient can reliably don, to prevent recurrence indefinitely.
The tapering pressure gradient does two things simultaneously: it reduces the effective cross-sectional area of the superficial veins, raising local blood velocity and reducing venous pooling and reflux dwell time; and it raises interstitial hydrostatic pressure, directly opposing the outward capillary filtration pressure that produces edema. Because pressure is highest at the ankle — where hydrostatic column pressure and disease burden are greatest — and progressively lower toward the thigh, the stocking assists rather than obstructs the natural cephalad flow of blood, unlike a uniformly tight bandage which can paradoxically trap fluid distally.
CEAP severity to compression class quick reference — C1–C2: 15–20 mmHg · C3–C4: 20–30 mmHg · C5–C6: 30–40 mmHg (multi-layer bandage while ulcer is open, stepping down to hosiery once healed).
The calf muscle pump is often called the "peripheral heart": with each step, contraction of the gastrocnemius and soleus muscles compresses the deep veins within their fascial sheath, ejecting blood upward while competent valves prevent backflow. In CVI this pump is mechanically inefficient — valve failure lets ejected blood reflux right back down. Graduated compression restores much of the pump's effectiveness and simultaneously counteracts the capillary filtration driving edema.
Fluid movement across the capillary wall follows Starling's principle: net filtration is driven by the balance of capillary hydrostatic pressure, interstitial hydrostatic pressure, and the opposing oncotic pressures of plasma and interstitial fluid. Venous hypertension raises capillary hydrostatic pressure well above normal, tipping the balance toward net filtration and edema formation. A graduated compression garment raises interstitial hydrostatic pressure directly, subtracting from the net outward pressure gradient — the mechanical equivalent of turning down capillary leakage at its source, without any pharmacologic intervention.
Compression stiffness matters as much as resting pressure. A stocking or bandage with high "static stiffness index" changes its pressure substantially between the relaxed and contracted calf — rising sharply during muscle contraction (systole of the pump) to squeeze the deep veins harder, then relaxing between steps (diastole) to allow arterial inflow and refilling. This dynamic interaction amplifies the pressure gradient that drives blood centrally with each stride, functionally compensating for incompetent valves by relying on total limb compression rather than a single competent valve to prevent reflux. Ambulation with compression in place, not bed rest, is therefore central to therapy — walking activates the very pump the stocking is designed to reinforce.
Venous leg ulcers account for the majority of chronic lower-extremity wounds. Decades of trial evidence establish compression therapy — not any topical dressing or drug — as the single intervention most strongly associated with healing. Sustained graduated pressure reverses the pathophysiology described in earlier stages: it lowers ambulatory venous pressure, reduces edema, improves cutaneous microcirculation, and creates conditions in which chronic wounds can finally re-epithelialize.
Systematic reviews (Cochrane) consistently find that venous ulcers heal faster and more completely with compression than without, and that higher-pressure, multi-component systems outperform single-layer or lower-pressure alternatives. Multi-layer bandaging combining an absorbent/padding layer with elastic or cohesive outer layers achieves target sub-bandage pressures of roughly 30–40 mmHg at the ankle and is generally changed weekly, accommodating the substantial reduction in limb volume that occurs as edema resolves over the first weeks of treatment. Once the wound bed is clean and granulating and drainage has diminished, many patients transition to a two-component compression system or a compression stocking with an easy-don liner, which improves comfort and adherence while sustaining therapeutic pressure.
Ulcer healing is not the endpoint — the underlying venous hypertension persists indefinitely unless the causative reflux is corrected surgically or endovenously, and even after ablation of superficial reflux, compression is often continued because deep and perforator disease may remain. Without maintenance compression, roughly two-thirds of healed venous ulcers recur within a year; with consistent daily use of a well-fitted, appropriately graduated stocking (commonly 20–30 mmHg for maintenance, or the highest class the patient can reliably don and tolerate), recurrence falls substantially. Practical adherence strategies — donning aids, layering two lower-pressure stockings instead of one very stiff one, and replacing hosiery every 3–6 months as elastic recoil degrades — matter as much as the prescribed pressure number itself.
A patient who heals a venous ulcer with compression but discontinues maintenance hosiery is statistically more likely than not to develop a recurrent ulcer within 12 months. Lifelong graduated compression, not a finite course of treatment, is the standard of care for CEAP C5–C6 disease.