Insufisiensi Vena Kronis

01Pathophysiology

Chronic venous insufficiency results from failure of the one-way valves within the veins of the lower extremities. These valves normally prevent retrograde flow and ensure that venous blood returns toward the heart against gravity. When they become incompetent, whether from primary degeneration, post-thrombotic damage, or congenital absence, blood refluxes downward and pools in the distal veins during standing and ambulation. The system most commonly involved is the great saphenous vein, though the deep veins and the perforating veins that bridge the superficial and deep systems can also be affected.

This persistent retrograde flow generates sustained venous hypertension in the capillary beds of the lower leg. The elevated pressure causes the capillaries to distend and become abnormally permeable. Fluid, plasma proteins, and red blood cells leak into the interstitial space. The extravasated red blood cells undergo degradation by tissue macrophages, releasing hemosiderin, which deposits in the skin and produces the characteristic brown-bronze pigmentation seen around the ankles and gaiter area. This is the hallmark skin change that connects pathophysiology directly to the clinical exam finding.

Simultaneously, leaked fibrinogen polymerizes into pericapillary fibrin cuffs, which act as a diffusion barrier for oxygen and nutrients. White blood cells become trapped in the sluggish, hypertensive capillaries and release inflammatory mediators, reactive oxygen species, and proteolytic enzymes. This cycle of chronic inflammation and tissue hypoxia leads to progressive fibrosis of the subcutaneous tissue, known as lipodermatosclerosis. Clinically, the lower leg becomes indurated and contracted, producing the classic "inverted champagne bottle" shape where the calf appears narrowed and firm while the ankle remains swollen.

If left untreated, the combination of tissue hypoxia, inflammation, and fragile skin eventually causes spontaneous skin breakdown or ulceration, most commonly over the medial malleolus. This location is important because it is where perforating veins are most concentrated and venous pressure is highest. The reason symptoms are worse at the end of the day and improve with elevation is straightforward: gravity exacerbates venous pooling when upright, and elevation reduces the hydrostatic column, lowering venous pressure.

02Classification and Clinical Manifestation

The internationally accepted classification system for chronic venous disease is the CEAP classification, which categorizes clinical severity from C0 to C6.

The key teaching point: CVI is clinically defined as C3 through C6. Classes C0 through C2 represent chronic venous disease but are not yet considered "insufficiency" because the functional consequences (edema, skin changes, or ulceration) have not developed.

03Diagnostic Workup

The best initial test for suspected CVI is duplex ultrasonography. This combines B-mode imaging (to visualize vein anatomy) with Doppler assessment (to detect the direction and duration of blood flow). The examination is performed with the patient standing or in a reverse Trendelenburg position, and the examiner uses provocative maneuvers such as the Valsalva maneuver or manual calf compression and release to elicit reflux. A reflux duration exceeding 0.5 seconds in the superficial veins or 1.0 second in the deep veins confirms valvular incompetence. Duplex ultrasound also serves to exclude acute DVT, which can present with similar swelling and must be ruled out before attributing symptoms to chronic insufficiency.

Before initiating compression therapy, it is essential to assess the arterial circulation using the Ankle-Brachial Index (ABI). This step is non-negotiable on the exam. The ABI is calculated as:

$$ABI=\frac{\text{Ankle systolic pressure}}{\text{Brachial systolic pressure}}ABI\; =\; \backslash frac\{\backslash text\{Ankle\; systolic\; pressure\}\}\{\backslash text\{Brachial\; systolic\; pressure\}\}$$

An ABI above 0.8 indicates sufficient arterial supply and confirms that compression can be safely applied. An ABI below 0.5 signals significant peripheral arterial disease, and compression is contraindicated because it could compromise already impaired arterial inflow and precipitate tissue ischemia. This is one of the most commonly tested safety checkpoints associated with CVI management.

Contrast venography, once considered the gold standard for mapping venous anatomy and reflux, has been almost entirely replaced by duplex ultrasound due to its non-invasive nature, reproducibility, and equivalent diagnostic accuracy. Venography is now reserved for complex pre-surgical planning or cases where ultrasound findings are inconclusive.

04Management and Treatment

Compression therapy is the cornerstone of CVI management at every stage. For patients with mild symptoms and early skin changes (CEAP C2 to C3), stockings delivering 20 to 30 mmHg are appropriate. For patients with advanced disease, lipodermatosclerosis, or active ulceration (C4 to C6), stockings delivering 30 to 40 mmHg are recommended. Stockings should be applied first thing in the morning before the patient stands and be worn throughout the day. The most critical step before prescribing compression is confirming that the ABI is above 0.8 to exclude significant arterial compromise.

For patients with active venous ulcers, multilayer compression bandaging or an Unna boot is the treatment of choice. The Unna boot is a semi-rigid, zinc oxide-impregnated gauze wrap applied from the toes to just below the knee. It provides sustained compression, protects the wound, and creates a moist healing environment. It is typically changed every one to two weeks.

Pentoxifylline (400 mg orally, three times daily) is the most well-supported pharmacologic adjunct for venous ulcer healing. It works as a methylxanthine derivative that decreases blood viscosity, inhibits platelet aggregation, and reduces inflammatory cytokine release. Studies show that adding pentoxifylline to compression significantly improves ulcer healing rates compared to compression alone. Aspirin at 300 mg daily has also been studied as an adjunct for venous ulcers, though the evidence base is less robust.

Lifestyle modifications are part of long-term management for all patients. Regular walking activates the calf muscle pump, which is the primary driver of venous return in the lower extremity. Patients should be counseled to avoid prolonged standing or sitting, maintain a healthy weight, and elevate their legs above the level of the heart for 30 minutes several times a day.

For patients whose symptoms persist despite conservative measures, or who have significant saphenous vein reflux documented on duplex ultrasound, endovenous ablation (laser or radiofrequency) is the current first-line procedural intervention. This has largely replaced open surgical stripping due to its lower morbidity, faster recovery, and equivalent long-term efficacy. Sclerotherapy with liquid or foam agents is used for smaller varicose and reticular veins. Surgical ligation and stripping is now reserved for anatomic configurations unsuitable for endovenous techniques.

Contraindications to note: Compression must not be applied if ABI is below 0.5 (absolute contraindication) and should be used with caution if ABI is between 0.5 and 0.8 (modified, reduced-pressure compression under close supervision). Pentoxifylline is contraindicated in patients with recent cerebral or retinal hemorrhage.

05Differential Diagnosis and Distractors

06Traps and High-Yield Pearls

The single most common way students lose points on CVI questions is by confusing venous ulcers with arterial ulcers. The exam will present a patient with a lower extremity ulcer and ask for either the diagnosis or the next step in management. The distinguishing details are often embedded subtly in the vignette: the location of the ulcer (medial malleolus vs. lateral malleolus or toes), the character of the wound base (moist granulation vs. pale/necrotic), surrounding skin changes (hemosiderin staining vs. shiny, hairless skin), and symptom timing (worse at end of day vs. worse with walking/claudication). If you see "brown discoloration around the ankles" and a shallow ulcer near the medial malleolus, you are looking at venous disease, not arterial.

The second major trap involves management. Students correctly identify CVI but then jump to an interventional or surgical answer. Compression therapy is always the first-line treatment for CVI, and on the exam, the "next best step" for a patient with a venous ulcer is compression (such as an Unna boot), not referral for ablation or surgery. However, there is an essential safety step: you must check the ABI before applying compression. A vignette that mentions absent pedal pulses, claudication, or a low ABI is testing whether you recognize that compression is contraindicated in the setting of severe arterial insufficiency. Applying compression to an ischemic limb is a dangerous error, and the exam expects you to catch this.

A third tested concept is distinguishing CVI-related edema from lymphedema. The vignette may describe chronic bilateral leg swelling and ask for the most likely diagnosis. The presence of hemosiderin staining, varicose veins, and a positive response to elevation points to venous insufficiency. Non-pitting edema, involvement of the toes and dorsal foot, a positive Stemmer sign, and the absence of skin discoloration points to lymphedema. The exam tests your ability to recognize these patterns rather than defaulting to a generic "edema" answer.

The core competency being tested across CVI questions is your ability to integrate history, physical exam findings, and the correct sequencing of diagnostic and therapeutic steps into a coherent clinical reasoning chain. The vignette gives you the clues; the question tests whether you can assemble them into the right diagnosis and avoid the management pitfall of skipping the ABI check before compression.