Life After Thrombosis: What Is Post-Thrombotic Syndrome

When a patient tells me 「I had thrombosis a year ago, but my leg still isn't the same」 — that is almost always a reason for a serious conversation. Post-thrombotic syndrome (PTS) is one of the most common long-term consequences of deep vein thrombosis (DVT), and unfortunately patients are rarely warned about it. Yet knowing about it matters: the earlier monitoring and treatment begin, the lower the risk of serious complications.

What Happens to a Vein After Thrombosis

When a clot forms in a deep vein, the body initiates a process of dissolving it — recanalization. However, this process is rarely 「clean.」 The clot is partly replaced by connective tissue, the vein wall scars, and the valves — delicate structures that prevent blood from flowing downward — become damaged or fail to close completely.

The result is chronic venous insufficiency with impaired blood outflow. Pressure in the calf veins rises, fluid leaks into the tissues, causing swelling and heaviness, and over time — skin changes.

According to various data, PTS develops in 20–50% of patients who have had DVT, with higher risk associated with proximal (femoral-popliteal) thrombosis, recurrent episodes, and inadequate anticoagulation therapy.

Symptoms: What to Watch For

PTS is a clinical diagnosis — that is, based primarily on complaints and physical examination. Typical manifestations:

• Swelling — more often by evening, reduces after a night's sleep, but may become persistent over time. I wrote separately about the nature of leg swelling.
• Heaviness and pressure in the calf or the entire leg, worsening with prolonged standing or walking.
• Pain — ranging from a dull ache to sharp pain with exertion.
• Skin changes: hyperpigmentation (darkening), hardening of the subcutaneous tissue (lipodermatosclerosis), eczema.
• In severe cases — trophic ulcers in the area of the medial malleolus.

Symptoms are assessed using the Villalta scale: mild, moderate, and severe PTS. This helps me choose a monitoring and treatment strategy for each individual patient.

If a leg suddenly becomes swollen, red, and hot — that is a reason to rule out recurrent thrombosis, not to wait for a scheduled appointment.

Monitoring Recanalization: Why Vein Duplex Ultrasound Is Needed

After a DVT episode, I recommend dynamic ultrasound monitoring. Vein duplex ultrasound allows assessment of:

1. 1Degree of recanalization — how much the vein lumen has restored, whether residual thrombotic material remains.
2. 2Valve condition — detecting reflux (reverse blood flow), which is the primary mechanism behind PTS development.
3. 3Collateral status — the bypass pathways the body forms in partial or complete occlusion.

I typically schedule the first follow-up vein duplex ultrasound 3–6 months after the acute episode, then as the clinical situation requires. Complete recanalization occurs within a year in some patients; in others the vein remains partially obliterated permanently — and knowing this is important for planning ongoing management.

At our clinic in Tashkent, vein duplex ultrasound is performed during the appointment: I conduct the examination myself and immediately interpret the result in the context of the patient's complaints. This avoids a gap between 「what the device showed」 and 「what it means for this particular person.」

Compression: Unglamorous, but It Works

Medical compression hosiery is not an elegant solution, but it is one of the most evidence-based approaches for PTS. It reduces venous pressure in the upright position, decreases swelling, and slows the progression of skin changes.

A few important points:

• The compression class is selected individually — most often class 2 (23–32 mmHg), and sometimes class 3 for pronounced changes.
• Stockings or knee-highs should be put on in the morning, before getting out of bed — while swelling is minimal.
• Hosiery does not treat the underlying cause, but significantly affects quality of life — this is supported by clinical practice.
• Compression is contraindicated in severe arterial insufficiency — so it should not be self-prescribed.

What Modern Phlebology Can Offer

Treatment of PTS is not limited to compression. Depending on the clinical picture, the following are considered:

• Venoactive drugs (diosmin, troxerutin, and others) — help reduce swelling and heaviness, although the evidence base varies across different medications.
• Appropriate physical activity: walking is the best 「pump」 for the deep veins. Prolonged standing in one place, on the contrary, worsens symptoms.
• Skin care: for dermatitis and hyperpigmentation, topical agents are prescribed — in some cases under dermatologist supervision.
• Endovascular interventions: for significant iliac vein obstruction, stenting may be considered in selected cases — this is a specialized procedure discussed on an individual basis.

It is important to understand: the goal of treatment in established PTS is symptom control and prevention of progression, not 「erasing」 the consequences of thrombosis. I always try to explain this to patients honestly, without unnecessary promises.

If you have previously had deep vein thrombosis and are under observation or wish to begin — this is precisely the case where regular visits have a direct bearing on outcomes.

When to Make an Appointment

See a phlebologist if, after a previous DVT, you notice:

• persistent or worsening leg swelling;
• darkening or hardening of the calf skin;
• pain during walking or at rest;
• any changes that concern you — even if 「lab results are normal.」

If swelling suddenly worsens, redness appears, there is sharp pain or shortness of breath — seek medical attention immediately: these symptoms require ruling out recurrent thrombosis or pulmonary embolism.

I see patients at M-Clinic (Tashkent). If getting there is difficult — a home visit for an initial examination and consultation is possible. You can book by phone +998 99 883-93-21 — we will do our best to find a convenient time.

This article is for informational purposes only and does not replace a consultation with a qualified physician. If you are experiencing symptoms, please see a specialist.