A novel compression solution for chronic venous insufficiency

Charles McCollum

Compression therapy is the mainstay of treatment for the symptoms of chronic venous insufficiency (CVI). CVI is treated with compression stockings or multilayer bandaging. However, as most compression stockings are supplied in standard sizes, they frequently failed to deliver the required pressure to treat CVI. What is more, multilayer bandaging is bulky and can be time consuming and inconvenient as it needs to be applied and then reapplied by a specially-trained nurse, often more than once a week, writes Charles McCollum.

Isobar, working in collaboration with the University of Manchester, has developed a unique technology that enables an individual’s leg to be scanned. 3D images of the legs are then generated, enabling a specially-developed computerised knitting machine to produce a precisely fitted and durable compression stocking. The main benefits of this technology are that precisely fitted compression garments are proven to be better at treating conditions such as CVI as the precise levels of pressure are consistently delivered to the individual’s leg. As they fit perfectly, they are also far more comfortable.

Isobar’s stockings fit perfectly due to 3D scanning of the limb and our proprietary yarn feed device that will ensure the specified pressure profile is delivered accurately throughout the affected limb. The accurate measurement and precise pressure profile enables the treatment system to provide garments for limbs of all shapes and sizes, even when deformed by previous injury or plastic surgery reconstruction.

The effect of these stockings on calf venous transit times has been reported following research carried out at University Hospital of South Manchester, where 20mmHg of compression at the ankle was found to reduce venous transit times by 38%. Isobar stockings delivering 25mmHg compression more than halve venous transit times increasing the flow of blood back to the heart.  This reduces blood pooling, swelling and the risk of deep vein thrombosis.

Since more than 50% of ulcers remain unhealed at 12 weeks (C Iglesias, et al on behalf of the Venous Team Health Technology Assessment 2004), there is considerable scope for savings, particularly since the stocking can continue to be worn after the ulcer has healed to prevent recurrence.

Isobar stockings are indicated to treat the symptoms of CVI in categories C2 to C6 inclusive (Eklof et al 2004):

  • C2: Varicose veins
  • C3: Oedema
  • C4: Pigmentation or eczema
  • C5: Healed venous ulcer
  • C6: Active venous ulcer

Further, Isobar stockings have been shown to be durable due to the way they are knitted and the quality of yarn used. They continue to deliver the specified pressure after more than 100 wash cycles. This enduring compression performance makes them cost-effective when compared with four-layer bandage if the treatment lasts for more than eight weeks (based on a weekly bandage change or less if bandages are changed more frequently).

Meta-analysis by the Cochrane Centre has shown that flight socks cut the risk of deep vein thrombosis by 90%. The analysis demonstrated a stronger link between the risk of developing a deep vein thrombosis and or/pulmonary embolism and long-haul flying than had been previously thought. Taking more than two flights of eight or more hours per month quadruples the risk; while taking more than four flights increases the risk sevenfold.

Compression garments should be worn for all long journeys, whether by plane, car or coach. Blood can pool in the lower limbs when sitting immobile, greatly increasing the risk of deep vein thrombosis. With its bespoke fit, Isobar socks are more comfortable and standard stockings and more effectively reduce the risk for frequent travellers. There is increasing awareness of this duty of care, with Isobar flight socks being increasingly used by global businesses and sportspeople, including the Olympic medal-winning Brownlee brothers, who want to mitigate their deep vein thrombosis risk during frequent flying.

Charles McCollum is the head of Academic Surgery and professor of Vascular Surgery in the Institute of Cardiovascular Research, University of Manchester, Manchester, UK