Unveiling the Science Behind Compression Stockings: A Comprehensive Guide

Compression stockings, or compression socks, are technically shaped hosiery that puts graduated pressure on the legs. The differentiated tights are tighter than usual socks and give off an intentional squeeze or pressure, therefore enhancing blood circulation and lessening discomfort in the lower extremities. The benefits of wearing compression stockings are numerous: pain and swelling relief, a lower risk of DVT, and other precluding circulatory abnormalities.

One of the major selling points of compression stockings over ordinary socks is the concept of graduated compression. This innovative design guarantees that the maximum pressure the stockings apply is in the ankle area while the compression level gradually decreases further up the thigh. As a result, the gradient of pressure plays a vital role—in encouraging blood flow toward the heart and discouraging any pooling or reflux of blood, which will flow into the feet or superficial veins.

This increases the velocity and volume of blood flow. The graded compression will promote this increment by intentionally varying the diameter of the larger veins.

Although acting not only against venous hypertension, the principle will also strengthen the effectiveness of the skeletal muscle pump to enable a much quicker venous return and lymphatic drainage.

Although compression stockings' main function is optimizing blood circulation dynamics, the physical mechanisms of their actions go further than mere compression. These specialist clothing items lead to a cascade of very difficult physiologic and biochemical events that together contribute to therapeutic efficacy.

It has been demonstrated that compression stocking therapy leads to amplified tissue oxygenation, as brought out by a rise in haemoglobin oxygenation and a drop in deoxygenated haemoglobin concentration in the affected limbs. This increase in oxygenation is more prominent when high-compression stockings are used.

Besides that, compression therapy has been associated with a reduction in the levels of pro-inflammatory cytokines, interleukin-1α, interleukin-6, and interferon-γ in the tissue of ulcers in active venous ulcer patients. This anti-inflammatory effect highlights that compression stockings are interdisciplinary and may have a role in modulating biochemical pathways other than their primary mechanical effect.

Compression stockings are available in various strengths of compression depending on an individual's specific need for therapy and preferences. They can be categorized by the level of sub-bandage pressure exerted at the ankle. General guidelines are developed for use and might need to be standardized.

Low compression:  Stockings in this category can exert pressure of less than 20 mmHg and below, or they are class 1 stockings.

Medium compression:  Stockings create a pressure between 20-30 mmHg or are graded as grade 2.

High compression:  Stockings create any pressure above 30 mmHg, generally graded as Class 3 or more.

This is important because the level of compression experienced in general will ultimately depend on different variables, including the stretchiness and rigidity of the stockings' material, the size and shape of the wearer's legs, and the activity of the person's legs when in stockings.

Definition Compression Stockings: Customized Clothing to Aid Circulation

Compression stockings are medical-grade hoses that apply uniform pressure to an individual's legs. These stockings, which fit tightly, are intended to help compress one's legs, promoting better circulation and less pain in the lower extremities. Relief from pain and swelling and prevention from DVT and other vascular problems are just some of the things people can expect to gain by wearing compression stockings.

Graduated Compression: Strategic Approach to Optimized Blood Flow

Graduated compression is one critical characteristic of compression stockings that differentiates them from regular stockings. This ingeniously designed stocking applies the highest pressure at the ankle region, and the compression gradually diminishes as it traverses up the leg. There is a good reason for this pressure gradient: it forces blood up toward the heart rather than pooling or refluxing down into the feet or laterally into the superficial veins.

Hence, graduated compression intentionally varies the diameter of the larger veins, thereby increasing the velocity and volume of blood flow. This also acts in opposition to venous hypertension, enhancing the action of the skeletal muscle pump and promoting faster venous return and lymphatic drainage.

A Multifaceted Mechanism: Physiological and Biochemical Impacts

While their primary function resides in optimizing circulatory dynamics, their mechanisms of action extend far beyond mere physical compression. Indeed, these specially designed garments elicit a cascade of complex physiological and biochemical processes that add to their therapeutic benefit.

It was documented that tissue oxygenation increased when compression stockings were applied. This effect is characterized by an increase of oxyhemoglobin and a reduction of concentrations of deoxyhemoglobin in the limbs at intensive compression. This effect is strongest with high-compression stockings.

Compression therapy has also been associated with reduced levels of pro-inflammatory cytokines, such as interleukin-1α, interleukin-6, and interferon-γ, in ulcer tissue from patients with active venous ulcers. This provides a background for the versatile action of compression stockings and their possible modulation of biochemical pathways rather than just mechanical housing.

Patients entrusted to us have varied therapeutic needs and personal preferences. Graduated compression stockings are manufactured with different compression strengths, which have been relatively prescribed based on the sub-bandage pressure given at the ankle level. Though there are calls for standardization, the following are general concepts being used:

1. Low compression refers to stockings with a strength of less than 20 mmHg (millimetres of mercury) or those classified as Class 1.

Mild compression: Socks and stockings graded between 20 to 30mmHg or Class 2.

Moderate compression:  Stockings issuing more than 30mmHg of graduated pressure are generally graded as Class 3 or higher.

Other factors that affect the overall level of compression on the wearer include the material stiffness and elasticity of the stockings, the size and shape of the person's legs, and their physical activity levels while the stockings are on.

Chronic Venous Insufficiency

Treating patients with CEAP class C4 venous skin changes typically includes compression stockings if the patient tolerates them. However, the best evidence for the effectiveness of compression stocking is in the setting of healing a venous ulcer.

High-quality research has definitively shown that compression therapy does increase the rate of venous ulcer healing compared with no compression or placebo. Meta-analyses show a statistically more significant proportion of ulcer healing and a shorter average healing time in cases treated using graduated compression stockings.

Evidence also exists that high-compression stockings measuring 30-40 mmHg might be more effective than medium or low-compression stockings in healing venous ulcers and preventing their recurrence.

Postsurgical or Interventional Treatment of Varicose Veins

Compression in the form of bandages or stockings is most commonly practised immediately after surgical or interventional treatment for varicose veins. This practice helps reduce thrombi formation, prevents pigmentation and matting, and minimizes inflammation and angiogenesis.

Although it remains unclear which compression modality is superior to another, graduated compression stockings may improve patient acceptance and compliance compared to bandages. Further studies are needed to give definite guidelines in this regard.

Prevention of Venous Thromboembolism

Hospitalized Patients

The role of graduated compression stockings in preventing venous thromboembolism and profound vein thrombosis has been well studied, although the strength of the evidence varies across different patient populations.

One systematic review of hospitalized patients excluded those with stroke. It showed that graduated compression stockings reduced the risk of DVT, especially when combined with other prophylactic measures like heparin or sequential compression devices.

In contrast, the seminal CLOTS trial 1 examined the effectiveness of thigh-length graduated compression stockings in reducing the risk of DVT after stroke and found nonsignificant differences in the rates of symptomatic and asymptomatic DVT between patients who wore and did not wear the stockings.

These findings further underline the need for future studies to help establish the exact efficacy of compression stockings in preventing VTE in a broad range of medical and surgical patient populations.

Travel-Related Venous Thromboembolism

Several studies have shown an increased risk for the development of VTE following prolonged travel, particularly by air. Specifically, a dose-response relationship has been found between the duration of travel and the magnitude of risk. Several studies have investigated the potential of graduated compression stockings in mitigating this travel-related risk.

A meta-analysis concluded that compression stockings might reduce asymptomatic DVT and leg oedema during prolonged air travel. Still, more extensive trials are required to assess their effect on more severe outcomes, such as pulmonary embolism or symptomatic DVT.

Postthrombotic Syndrome

Prevention

Postthrombotic syndrome is a common complication of DVT, ranging from mild leg pain and swelling to severe skin changes with ulceration. Meta-analysis showed that graduated compression stockings decrease the incident cases of severe postthrombotic syndrome and any postthrombotic syndrome after a proximal DVT event.

Based on this evidence, authoritative guidelines—such as those published by the National Institute for Health and Care Excellence in the UK—recommend that a below-knee graduated compression stocking with an ankle pressure greater than 23 mmHg be used for at least two years after the diagnosis of proximal DVT, provided that there are no contraindications.

This recommendation was recently challenged by the double-blind, multicenter randomized controlled trial SOX trial of 806 patients, which found no significant difference in the incidence or severity of postthrombotic syndrome between patients treated with compression stockings compared to those receiving placebo stockings for two years following their first proximal DVT event.

Treatment

The evidence for graduated compression stockings in treating established postthrombotic syndrome is limited and of low quality. Two RCTs had conflicting results: one found an overall nonsignificant difference in treatment failure rates between the graduated compression stockings and placebo stocking groups, and the second RCT detected no clear differences in symptom improvement or worsening among all treatment arms that included compression stockings, vasoactive drugs, or combination treatment.

Lymphedema and Chronic Leg Edema

Lymphedema is an impairment of lymphatic drainage, resulting in the chronic accumulation of fluid and subsequent swelling in limbs. Internationally, it is generally accepted that the standard of care for lymphedema involves two phases of treatment: an intensive reduction phase, during which swelling is reduced through the use of various modalities, such as compression bandaging, and a long-term maintenance phase, often employing the use of graduated compression stockings.

Evidence indicates high compression stockings of 30-40 mmHg successfully reduce lymphedema during the maintenance phase, with suggestions for the highest level of compression—20-60 mmHg—tolerable by the patient for optimum therapeutic benefit. Lower compression may be appropriate for milder lymphedema or general leg oedema cases.

Superficial Thrombophlebitis

In most cases, superficial thrombophlebitis mandates complex management, which may involve topical therapy, anticoagulation, and nonsteroidal anti-inflammatory drugs; surgical intervention may be necessary in some patients. In this respect, graduated compression stockings are of additional benefit for alleviating local symptoms and possibly preventing an extension of venous thrombosis.

A systematic review has revealed that surgical treatment using graduated compression stockings was associated with lower VTE rates and the progression of superficial thrombophlebitis than stocking use alone.

Pregnancy

Although evidence is limited, some studies suggested that graduated compression stockings convey subjective alleviation from common pregnancy-related leg symptoms, including swelling, tiredness, and pain, by improved venous emptying. However, a Cochrane systematic review has concluded that compression stockings are ineffective in reducing leg oedema in pregnancy.

Also, in a small randomized controlled trial, although compression stockings did not prevent the formation of varicose veins during pregnancy, they indeed improved general leg symptomatology in these patients.

Compression stockings have become one of the most versatile and valuable therapeutic tools for managing various vascular and lymphatic conditions. Their worth in maintaining proper blood flow, decreasing discomfort, and promoting healing makes them invaluable tools for improved overall vascular health.

While the evidence for their use varies across different clinical indications, high-quality data firmly supports the application of compression stockings in chronic venous insufficiency, particularly for healing venous ulcers. The prophylactic potential of compression stockings in preventing DVT, postthrombotic syndrome, and travel-related VTE is well documented; however, there are some conflicting findings.

As in any medical intervention, the wise application of compression stockings considers the possibilities of absolute and relative contraindications, proper fitting and measurement by a trained professional, and ongoing monitoring for adverse effects. Addressing patient concerns, education, and tailoring the required compression level with the type of stocking material used will go a long way to ensure better compliance and therapeutic effect.

Further research is warranted in refining optimal compression pressures, stocking lengths, and specific clinical scenarios in which compression stockings can benefit the most. With the adoption of these specialized garments and their integration into a holistic vascular health approach, healthcare professionals can empower their patients toward better circulation, reduced discomfort, and improved quality of life.