FOUR LAYER BANDAGINGFOR VENOUS ULCER
Vascular Surgeon, Lilavati Hospital,
Mumbai 400 050.
The successful management of venous leg ulcers represents a significant clinical
problem and a major drain on limited financial resources. Research has shown
that majority of the ulcers can be induced to heal by the application of adequate
levels of sustained graduated compression, although this technique is contraindicated
for the treatment of ischaemic ulcers.
Bandages vary greatly in their ability to provide sustained compression due
to differences in their structure and the content of elastomeric yarns. Other
factors such as limb circumference and shape will also have an important influence
on the pressure produced beneath the compression bandage.
Leg ulcers are a chronic condition and these incur a significant financial implication
on the patients. These ulcers can be caused by number of physiological or biochemical
disorders either individually in combination, but the majority, approximately
70% are associated with venous disease.
The prevalence of active venous ulcers in the United Kingdom is around 1.5/10,000
of the adult population, although the number of people who develop at least
one episode of ulceration may be 3-4 times greater than this. The prevalence
of venous ulcerations increases with age and is more common in women than in
Bandages have a history stretching back thousand of years to the time of the
ancient Egyptians, who used simple woven fabrics, often coated with adhesives,
resins, and other medicaments as dressing for a wound healing. Like some of
the bandages used today, these were made from non-extensible fabric and probably
required considerable skill on the part of the user to ensure correct application.
In the 17th century, Pierre Dionis who was surgeon-in-ordinary to the queen
of France and to the Empress Maria Theresa of Austria recommended the use of
rigid lace-up stockings made from coarse linen or dog skin to apply compression
in the treatment of leg ulcers. The bandages available at that time were not
suitable for the application of sustained, controlled compression because of
their inelastic nature. It was not until the middle of 19th century that the
first elasticated bandages containing natural rubber were manufactured. In 1878,
Calendar published a letter in the Lancet, which described the use of these
materials in the management of varicose veins.
ANATOMY AND PHYSIOLOGY OF VENOUS SYSTEM OF THE LEG
The veins of the leg are divided into superficial and deep systems. The deep
veins, which come together to form the popliteal and femoral veins lie within
the fascia and are responsible for the venous return from the leg muscle. Also
within the fascia, the soleus and gastrocnemius muscles have dilated valveless
sinusoids, which fill with blood when the leg is at rest. Together these deep
vascular structures, have a combined volume of about 100 to140 ml comparable
to that of one of the ventricles of the heart.
The long saphenous vein which runs along the medial side of the vein from foot
to groin and the short saphenous vein which runs at the back of the calf, from
foot to knee are the major vessels of the superficial venous system. These vessels
lie outside the fascia and are responsible for the venous return from the skin
and subcutaneous fat.
The two systems are joined by communicating veins, sometimes called perforators
as they perforate the deep fascia. The perforators, like the other veins in
the leg, contain valves that permit the flow of blood in one direction only,
from the outer or superficial system inwards to the deep veins. The venous pressure
at the ankle of the subject who is lying supine is around 10 mm Hg, but on standing
this will rise by about 80 mm Hg, due to an increase in hydrostatic pressure.
During walking, as the foot is dorsiflexed, the contraction of the calf muscle
compresses the deep veins and soleal sinuses to the point at which they become
almost totally collapsed, producing pressures of upto 250 mm Hg and emptying
them of blood. As the foot is plantar flexed, the pressure in the veins falls,
the proximal valves close, and the veins are refilled by blood passing through
the perforators from the superficial system. During this cycle, in a normal
leg, the distal valves of the deep veins and the valves of the perforators will
ensure that the expelled blood can go only in one direction i.e. upwards, back
to the heart.
The pumping action of the calf muscle causes the hydrostatic venous pressure
in the ankle region to gradually fall until it reaches a steady state, usually
about 30 mm Hg in the deep veins and 40 mm Hg in the superficial veins. If the
subject then stands still, the pressure in both systems will slowly return to
a stable value of about 90 mm Hg, a process that usually takes about 20-30 seconds.
THE EFFECT OF DAMAGE TO THE VENOUS SYSTEM
Blockage or damage to venous system will cause disruption to normal blood flow,
which may manifest itself in a number of different ways according to the site
and extent of the damage. If the valves in the superficial system are affected,
venous return will be impaired and blood may accumulate in the veins causing
them to become distended leading to the formation of varicosities (varicose
If the function of the perforator valves is impaired the action of the calf
muscle pump will tend to cause blood to flow in the reverse direction into the
superficial system increasing the possibility of damage to the superficial vessels.
Following deep vein thrombosis that results in complete or partial obstruction
of a deep vein, the unrelieved pressure produced by the calf muscle pump on
the perforator valves may cause these to become incompetent. If this occurs,
there will be a large rise in the pressure in the superficial system which may
force proteins and red cells out of the capillaries and into the surrounding
tissue, Here, the red cells break down releasing red pigments which causes staining
of the skin called lipodermatosclerosis, an early indicator of ulcer formation.
DIAGNOSIS OF VENOUS ULCERATION
Ulcer characteristics - Its location is most often around the medial malleolus
(gaiter area). The ulcer base is usually pink with healthy granulation tissue
with an irregular border. There is usually a copious exudate from the ulcer.
Pain is usually not present but may occur if the superficial nerves are exposed.
The surrounding skin is pigmented with lipodermatosclerotic changes. The limb
is usually swollen thereby making peripheral pulses difficult to palpate.
1. Hand held Doppler
2. Colour Doppler scan
3. Ankle-brachial index
4. Venous plethysmography
1. Compression Bandaging
2. Corrective Venous Surgery
3. Maintenance treatment
For patients with venous disease, the application of graduated external compression
can help to minimise or reverse the skin and vascular changes described previously,
by forcing fluid from the interstitial spaces back into the vascular and lymphatic
compartments. As the pressure within the veins of a standing subject is largely
hydrostatic, it follows that the level of external pressure which is necessary
to counteract this effect will reduce progressively up the leg, as the hydrostatic
head is effectively reduced. For this reason it is usual to ensure that external
compression is applied in a graduated fashion, with the highest pressure at
FACTORS WHICH DETERMINE SUB-BANDAGE PRESSURE
The pressure developed beneath any bandage is governed by the tension in the
fabric, the radius of curvature of the limb and the number of layers applied.
Applying a bandage with a 50% overlap produces 2 layers of fabric which generates
a pressure twice that produced by a single layer. Sub bandage pressure can be
calculated using a simple formula derived from the Laplace equation as follows:
P = (TN x 4630)/CW where)
P = Pressure in mm Hg
T = Bandage tension in kgf
C = Circumference of the limb in cms.
W = Bandage width in cms
N = No. of layers applied
Sub-bandage pressure is therefore directly proportional to bandage tension but
inversely proportion to the radius of curvature of the limb to which it is applied.
This means, therefore, that a bandage applied with constant tension to a limb
of normal proportions will automatically produce graduated compression with
the highest pressure at the ankle. This pressure will gradually up the leg as
the circumference increases.
Effects of compression
Graduated compression has shown to
1.Increase blood velocity in the deep veins
2.Reduce oedema and therefore reduce the pressure differential between the capillaries
and the tissues.
3.Reduce distension of superficial veins and reverse venous hypertension
4.Improve the healing rate of chronic venous ulcers.
Sarin. S. in his recent research has indicated that external compression restores
valve function in a proportion of superficial and deep veins by decreasing vein
diameter and therefore improving overall venous function. The full physiological
effect of compression is still not fully understood and required further research.
Stemmer demonstrated theoretically that 40 mm Hg pressure at the ankle was required
to reverse chronic venous hypertension. The 4 layer bandage system was developed
to apply 40 mm Hg pressure at the ankle graduated to 17 mm Hg pressure at the
knee using bandages of different properties.
It is claimed that dressings influence ulcer healing. Following extensive randomised
control studies, involving different dressing types usedconjunction with the
4 layer bandage, it was found that dressings had little influence on ulcer healing.
Therefore, in the majority of ulcers a simple non-adherent dressing is used.
Viz. Sofratule, Adaptic, lnadine, etc. It is very important to choose a dressing
that will not aggravate the patientís ulcer or surrounding skin.
All bandages used are 10 cms in width and should be applied from the base of
the toes to the knee joint.
Layer 1 - Orthopaedic wool such as Velband or Softban. This is used to absorb
exudate and redistribute pressure around the ankle, protecting the bony prominences
from excessive pressure. It also fills in the troughs behind the malleoli where
little pressure is exerted. The bandage is applied without tension in a loose
Layer 2 - Cotton crepe bandage. This is arguably the least effective layer in
the combination. Its function is to increase absorbency and to smooth the orthopaedic
wool layer, thereby preserving the elastic energy of the main compression layers.
The cotton crepe bandage is also applied in a spiral.
Layer 3 - Elasticated crepe bandage. This is a highly elastic, conformable compression
bandage. It is applied at mid stretch in a figure of 8 with a 50% overlap. This
weaves a mean pressure of 17 mm Hg on ankles measuring 18-25 cms.
Layer 4 - Coban. This is a light weight, elastic, cohesive bandage. When applied
at mid stretch with 50% overlap to an ankle measuring 15-25 mm, it gives an
ankle pressure of 23 mm Hg. Coban maintains the 4 layers in place until removal
and adds durability to the system.
The combined pressure of these bandages is 40 mm Hg at the ankle graduated to
17 mm Hg pressure at the knee. This system has been further developed to accommodate
differing limb circumferences. As the limb circumferences is variable, and may
decrease considerably in the first few weeks, owing to a reduction of oedema
following application of compression, the measurement of ankle should be repeated
at frequent intervals.
Each limb must be assessed carefully and individually before applying compression
and the bandager must be aware of potential problems that each limb may present,
In particular, very thin legs need extra padding to prevent excessive pressure
over the bony prominences and the tendinous area over the dorsum of the foot,
which may cause pressure necrosis. This extra padding can be achieved in a variety
of ways, e.g., by pleating the orthopaedic wool layers, thus protecting the
Conversely, a large or oedematous limb will need a stronger elastic bandage
to achieve adequate compression. In ankles measuring more than 25 cms, a stronger
elasticated crepe bandage is used in place of dynaflex to achieve 40 mm Hg pressure.
Ulcer lying behind the malleoli may not receive adequate compression. A pressure
pad is placed over the primary dressing to apply direct pressure to the ulcer
bed. Many chronic leg ulcer patients who have been bandaged for long periods
of time are immobile and loose a proportion of their calf muscle bulk. Effective
graduated compression relies on the natural gradient of the leg, which is decreased
in these patients. This is simply rectified by padding the calf area and thus
redefining the shape of the leg.
HAZARDS OF COMPRESSION BANDAGING
* Arterial disease is a contra indication. Patient with an ABI of less than
0.8 should not receive full compression. Application of compression to a limb
with poor circulation may lead to pressure necrosis and may even necessitate
* Compression can cause pressure necrosis in absence of arterial disease in
patients with narrow ankles and thin calves. Excessive pressure may beapplied
over bony prominences and the malleoli.
* Compression should be used with caution for patient with rheumatoid arthritis
or diabetes mellitus, as these patients are susceptible to microvessel disease.
Application of compression can cause further occlusion of these vessels and
result in pressure necrosis.
* Patients with oedema secondary to heart failure should not receive compressions
to reduce oedema as this may produce a sudden increase in venous return, which
may further exacerbate the heart failure.
Following healing of venous ulcer, the underlying cause should be corrected
surgically if possible viz; varicose veins surgery, subfascial endoscopic perforator
ligation, deep venous valve repair.
This is the most important treatment modality that prevents recurrence of ulceration.
A class II compression stockings should be worn life long.
Sustained compression of over 40 mm Hg achieved with a 4 layer bandage results
in rapid healing of chronic venous ulcers that have failed to heal in many months
of compression at lower pressures with more conventional bandages.