Compression stockings are designed to provide support to the legs and veins, assist with circulation, and minimize swelling. The compression is graduated, with the strongest support starting at the ankles and gradually decreasing towards the top of the garment. This gradual support works in conjunction with the pumping action of the calf muscles, which also assist with circulation.
Compression garments offer many benefits, such as reducing swelling, decreasing the chance of a blood clot, and provide post-surgical support. By increasing blood flow, compression garments also assist in flushing harmful fluids out of the body during post-surgical recovery. The purpose of compression garments for Lymphedema is to maintain the decongestive effect achieved during therapy, to prevent reaccumulation of fluid into the tissues. By providing external compression, fluid is forced in a proximal direction, improving the function of the valves contained in our veins. Compression garments also provide a counterforce on our muscles, thus improving its efficiency.
Compression Garments for Lymphedema
There is a wide array of compression garments to choose from and deciding which one is suitable can be daunting. Having the right fit is the most important aspect - compression garments are effective only if they are worn consistently and the patient is satisfied. Therapeutic benefit is lost if the garment is stored away.
The “grades” for compression are measured in mmHg (millimeters of mercury just like the pressure of a blood pressure cuff):
- 15-20mmHg – no prescription required; preventative; for tired achy legs; good for mild swelling experienced on airplane flights
- 20-30 mmHg (class I) – no prescription required; for mild lymphedema in upper or lower extremity
- 30-40 mmHg (class II) – prescription required; for moderate lymphedema in upper or lower extremity
- 40-50 mmHg (class III) – prescription required; for severe lymphedema especially of lower extremity
- 50-60 mmHg (class IV) – prescription required; for severe lymphedema of lower extremity
Flat knit vs Circular Knit Material
Circular knit garments are manufactured on a cylindrical knitting machine, which allows for them to be seamless. The same number of needles is used throughout the length of the garment. The size of the needles as well as the degree of pre-stretch of the elastomer, provides for a smaller circumference on the distal and a larger circumference on the proximal portion of the garment.
In flat knit garments, the number of needles varies in accordance with the patient’s measurements, which provides these garments with the same density throughout the length of the garment. These garments can be manufactured in any shape or size.
Most ready made garments are circular knit and flat knit are generally custom made.
Higher levels of pressure (>50mmHg) can only be achieved with flat knit garments Circular knit fabrics are less expensive and cosmetically more attractive because they do not have a seam and can be produced using finer and sheerer materials. Flat knit garments are more dense but provide a more precise fit, and because of their construction when stretched over a limb there are more holes for the skin to breathe.
Off the Shelf/Pre-Made vs. Custom Measure
Custom fitted garments are made for limbs that have an unusual shape such as where the top of the limb is much larger than the bottom, or the limb does not fit into the manufacturer sizing charts – ie. too small or too large. Since the greatest compression needs to be at the distal end (lower arm or leg) of the limb, if the garment fits the top of the limb and is loose at the bottom, this will probably cause the fluid to travel down to the hand or foot. If the limb is symmetrical in shape and fits into the manufacturer size chart, the person may be able to fit into a ready made “off the shelf” garment.
At no time should the garment have a tourniquet effect, which will cause more swelling below the level of the tight area.