What is Post-Thrombotic Syndrome (PTS)?

Post-Thrombotic Syndrome (PTS)

Post-thrombotic syndrome (PTS) is a chronic condition characterized by venous insufficiency that develops following deep vein thrombosis (DVT), manifesting as pain, swelling, skin changes, and in severe cases, ulceration of the affected limb. 1

Definition and Pathophysiology

• PTS is a syndrome of chronic venous insufficiency that occurs as a long-term complication after deep venous thrombosis (DVT) 1
• The pathophysiology primarily involves venous hypertension, which can result from:
  • Persistent thrombotic veno-occlusion
  • Venous valvular reflux due to damage from previous thrombosis
  • Other causes of impaired venous return 1
• Inflammation contributes significantly to venous valvular damage during the post-thrombotic process 1
• Ambulatory venous hypertension occurs from outflow obstruction due to residual thrombus and/or valvular incompetence (reflux) 1

Clinical Manifestations

Symptoms

• Pain, heaviness, and fatigue in the affected limb 1
• Cramping (often occurring at night) 1
• Swelling that worsens with prolonged standing or by the end of the day 1
• Itching and paresthesia 1
• Symptoms typically improve with rest or limb elevation 1

Signs

• Edema of the affected limb 1
• Dilated superficial collateral veins 1
• Hyperpigmentation (brownish discoloration) 1
• Venous ectasia (dilated veins) 1
• Lipodermatosclerosis (hardening of the skin and subcutaneous tissues) 1
• Stasis dermatitis 1
• Venous ulceration in severe cases 1

Epidemiology and Risk Factors

• PTS develops in 20-50% of patients within 1-2 years after symptomatic DVT 2
• Severe PTS, including venous ulcers, occurs in 5-10% of cases 2
• The estimated frequency of PTS following upper/lower extremity DVT in children is approximately 26% 1
• Principal risk factors include:
  • Anatomically extensive DVT (particularly iliofemoral) 2
  • Recurrent ipsilateral DVT 2
  • Persistent leg symptoms 1 month after acute DVT 2
  • Obesity 2
  • Older age 2
  • Residual thrombus after therapy 1

Diagnosis

• No single gold standard test exists to diagnose PTS 1
• Diagnosis is primarily clinical, based on characteristic symptoms and signs in a patient with prior DVT 1
• Diagnosis should generally be deferred until at least 3-6 months after the acute DVT to allow resolution of acute symptoms 1

Clinical Assessment Tools

• The Villalta scale is commonly used and incorporates:
  • 5 subjective symptoms (pain, cramps, heaviness, paresthesia, pruritus)
  • 6 objective signs (pretibial edema, skin induration, hyperpigmentation, redness, venous ectasia, pain on calf compression)
  • Presence or absence of ulcer 1
• Other assessment tools include:
  • Ginsberg measure
  • Brandjes scale
  • CEAP (Clinical-Etiologic-Anatomic-Pathophysiologic) classification
  • Venous Clinical Severity Score (VCSS) 1

Impact on Quality of Life

• PTS significantly reduces quality of life and is costly 2
• Generic physical quality of life for patients with PTS is worse than for people with chronic diseases such as osteoarthritis, angina, and chronic lung disease 1
• Quality of life scores worsen significantly with increasing severity of PTS 1

Upper Extremity PTS

• Upper extremity PTS occurs following upper venous system thrombotic events (UVSTE) 1
• Frequency ranges from 7% to 46%, with a weighted mean frequency of 15% 1
• Risk factors differ from lower extremity PTS due to mechanical differences (e.g., gravity, weight bearing) 1
• Central venous catheter-related UVSTE is associated with decreased risk of PTS compared to primary thrombosis 1

Prevention and Management

• Prevention of initial DVT through appropriate thromboprophylaxis is the best way to prevent PTS 3
• Adequate anticoagulation for the initial DVT and avoiding subtherapeutic INRs in patients treated with vitamin K antagonists is important 3
• Compression therapy with a minimum pressure of 20-30 mmHg may help manage symptoms 4
• Catheter-directed thrombolytic techniques may be considered on a case-by-case basis, particularly for patients with extensive thrombosis, recent symptom onset, and low bleeding risk 3
• For established PTS, daily use of 20-30 mmHg knee-length elastic compression stockings is recommended 3
• Supervised exercise training programs may improve PTS symptoms 3
• Management of post-thrombotic ulcers should involve a multidisciplinary approach 3

Pitfalls to Avoid

• Failing to consider PTS in patients with chronic leg symptoms and a history of DVT 4
• Using compression therapy in patients with significant peripheral arterial disease without appropriate vascular evaluation 4
• Delaying diagnosis by not waiting an appropriate time after acute DVT 1
• Not distinguishing PTS from recurrent DVT, which requires different management approaches 1