Post-thrombotic limb and post-thrombotic syndrome (PTS)

The post-thrombotic limb develops slowly, over a period of several years.

It is recognised by:

• chronic swelling of the limb with brawny oedema
• varicose veins with incompetent perforating veins
• varicose eczema with inflammation and haemosiderin deposition above the middle malleolus
• venous ulceration above the middle malleolus
• "beer-bottle leg"

Note that the term Post-thrombotic syndrome (PTS) is a term used to describe a group of leg symptoms (heaviness, chronic pain, cramps, itch) and signs (swelling and skin changes such as hyper-pigmentation, redness, ulceration) in the affected limb following a DVT (1).

• PTS is an under recognized, under diagnosed and under treated condition (2).
• one in every 2–3 patients with deep-vein thrombosis (DVT) of the lower extremity will develop PTS despite receiving anticoagulant therapy (1)
• the risk of developing PTS is markedly increased in recurrent DVT (2)

PTS results from deep venous valvular damage (ultimately incompetence) caused by DVT (1).

The following have been found to be associated with an increased risk of PTS:

• proximal DVT
• previous ipsilateral DVT
• older age
• obesity
• varicose veins (1)

There is evidence that elastic compression stockings reduce the occurrence of PTS after DVT (3):

• patients who have a proximal DVT can reduce the incidence of post-thrombotic syndrome by wearing graduated elastic compression stockings on the affected leg for at least two years after the initial event (optimal duration uncertain)(3)

Additionally maintaining an ideal body mass index (BMI) and regular exercise regime to maintain an adequate calf muscle pump function will also help in prevention of PTS (2).

Catheter-directed thrombolysis has been shown to prevent PTS in patients with acute deep vein thrombosis in the upper half of the thigh (5)

Reference:

• (1) Prandoni P, Kahn SR. Post-thrombotic syndrome: prevalence, prognostication and need for progress. Br J Haematol. 2009 May;145(3):286-95
• (2) Institute for Clinical System Improvement (ICSI) 2011. Health Care Guidelines: Venous Thromboembolism Diagnosis and Treatment
• (3) Cochrane Database Syst Rev. 2004;(1):CD004174.
• (4) MeReC Bulletin (2003); 13(4):13-16
• (5)Enden T et al. Long-term outcome after additional catheter-directed thrombolysis versus standard treatment for acute iliofemoral deep vein thrombosis (the CaVenT study): a randomised controlled trial. Lancet. 2012 Jan 7;379(9810):31-8.