Laboratory measurements of compression stockings

The effects of compression depend widely on the exerted pressure, which should be adapted to the underlying condition. Basically, the pressure of a stocking is calculated from the force–extension diagram of the elastic fabric on a wooden leg model with defined circular cross-sections using Laplace’s formula (Fig. 6.10). The range of the compression pressure indicated by the manufacturers is determined by the measurement of the force which is necessary to stretch the stocking at certain leg levels (B, B1, C, D, F, G) in a transverse direction. The proportion of stretch and force for each circumference level, which corresponds to the steepness of the so-called slope in the hysteresis curve, reflects the elasticity of the material of the stocking.

Figure 6.10 Hysteresis curve generated by a bobbinet elastic fabric.

(Courtesy of Beiersdorf-Jobst, Charlotte, N.C.)

Several industrial measuring systems for obtaining hysteresis curves are used, such as the Hosy method, the Hatra tester, the Instron method, the French ITF method, and others.

Measuring points, lengths, and girths defined by the European standardization proposal (CEN, Centre Européen de Normalisation)⁶⁹ are shown in Figure 6.11.

Figure 6.11 Measuring points, lengths, and girths on the human leg. Note: measurements should be taken of the patient’s leg in a standing position.⁶⁹

Table 6.1 gives a comparison of compression classes for ready-to-wear and custom stockings used in several countries. The range of compression pressures, and also the verbal description of these classes, are amazingly variable from one country to another. Additionally, it is important to realize that the given ranges are measured by different methods, so comparisons are problematic. These facts underline the necessity of in vivo pressure measurements on the individual leg, at least in future clinical studies. For a better universal understanding, it is recommended to use the pressure range in mmHg rather than compression classes in general.

The pressure values in Table 6.1 refer to level B. The European prestandard⁶⁹ defines the ranges of pressure profiles in comparison with the pressure at the smallest leg circumference (position B) as follows: for level B1 70% to 100%, for C and D 50% to 80%, and for F and G 20% to 40% for compression classes III and IV; 20% to 60% for compression classes A and I, and 20% to 50% for compression class II (Fig. 6.12). The producers of compression stockings recommend adjusting the compression class according to the clinical severity.

Figure 6.12 Diagram comparing the degree of compression exerted at various locations on the leg with different compression class stockings. B is the pressure generated at the ankle; D is the pressure generated at the knee; G is the pressure generated at the superior thigh. Note that there is a graduation of pressure with all classes of stockings, with the highest pressure exerted at the ankle. Also note that the most significant difference in pressure generated by the different classes of stockings is at the ankle.

(Courtesy of Juzo, Ohio.)

There is no American standard. Table 6.2 gives an example as recommended by one company (BSN-Jobst, Charlotte, N.C.).

Measurements of interface pressure on the leg

Compression therapy is a very effective treatment tool for which the ‘dosage’, which is the pressure on the individual leg, has been completely underestimated up to now. At least for clinical trials comparing different compression products, we need to measure the interface pressure on the individual leg and not just rely on the specifications of the producers. This is true not only for compression stockings whose pressure range is measured by different laboratory methods, making a comparison in treated patients problematic, but even more so for compression bandages. The pressure exerted by a compression bandage depends completely on the skill and experience of the bandager, and only single standards are available that are far away from clinical practice.

Several instruments are available, which should be calibrated on the leg according to a recent consensus recommendation.⁸¹ In this consensus paper, some prerequisites of an ‘ideal’ pressure sensor are summarized. One location that should always be included in future pressure measurements is B1. This is where the tendinous part of the gastrocnemius muscle changes into the muscular part, showing the most pronounced protrusion of the tendon and the most extensive enlargement of the leg circumference during dorsiflexion or by standing up from the supine position. Whenever in vivo measurements of interface pressure are performed, it is essential to indicate the exact measuring point, the main specifications of the instrument, including the dimensions of the probe, and the body position in which the measurements have been performed. Figure 6.13 shows a pressure measuring instrument which allows continuous pressure registration. The flat probe is inflated only when pressure is measured and can stay on the leg for several days. Figures 6.4 and 6.5 show pressure curves obtained with this instrument.

Figure 6.13 Instrument to measure interface pressure continuously. The flat probe is filled with 2 mL air and may be left deflated on the leg for several days.

(Picopress, Micolab, Italy.)

Resting and working pressure

Some probes allow measurements of interface pressure not only at rest but also continuously during movement. Figure 6.14 shows an example where the interface pressure on the distal leg was measured continuously in different body positions, both for an inelastic and for an elastic bandage. Starting with comparable resting pressure for both bandages, the inelastic bandage has a higher working pressure than the elastic bandage. This difference has a major impact on the efficacy of the compression device concerning edema reduction and improvement of venous pump. Stockings with high stiffness or slope value, even at the same compression level, are better for patients with edema from CVI or other causes.⁸² Inelastic bandages are more effective to reduce venous refluxes and ambulatory venous hypertension.^37,43

Figure 6.14 Differentiation between inelastic (<100% stretch) and elastic bandage material (>100% stretch) based on measurements in textile laboratories.

Measurements of intramuscular pressure have shown higher resting pressure with elastic than with inelastic material, suggesting that elastic compression applied over a long period in the recumbent posture may impede microcirculation and jeopardize tissue viability.⁸³

Measurement of stiffness

Stiffness is defined as the increase in compression per centimeter increase in the circumference of the leg, expressed in millimeters of mercury per centimeter.⁶⁹ This parameter characterizes the distensibility of a textile as well as the elastic property of a composite bandage, which plays an important role concerning the performance of a compression device during standing and walking. Stiffness may be measured in the laboratory, where it corresponds to the slope of the hysteresis curve. The fact that it can also be assessed by in vivo measurements on the individual leg will certainly achieve increasing practical importance in future trials.^80,81,84

Measurement of dynamic stiffness during walking requires sophisticated instrumentation and can therefore not be used in routine clinical practice.⁸⁰ In order to obtain valuable information on the elastic property of a compression device, which may be quite complex when several materials are combined, the so-called ‘static stiffness index (SSI)’ may be a useful alternative.⁷⁹ A calibrated pressure sensor is fixed to the medial aspect of the leg at B1. This is the area which will show the most extensive changes in local curvature and leg circumference when the body position is changed between supine and standing. The difference between the interface pressure in the standing and in the lying position, called SSI, is a valuable parameter for the stiffness of the compression system, which determines the relationship between resting and working pressure. As is shown in Figure 6.15, inelastic material produces a much higher pressure increase in the upright position than elastic material. It is important to note that different indices may be obtained with different sensors. Therefore, reliable comparisons of different compression devices will only be possible by testing using the same sensor on the same site.

Figure 6.15 Resting and working pressure of an inelastic bandage (left) and an elastic bandage (right), measured at B1. During movement (dorsiflexions in the sitting position, tip-toes in the standing position) the pressure fluctuations are much higher with the inelastic bandage compared to the elastic bandage. By standing up from the sitting position the pressure rises by 23 mmHg under the inelastic bandage, but by only 8 mmHg under the elastic bandage. This increase of pressure characterizes stiffness.

It has been shown that different padding materials may change the stiffness of the final bandage.⁸⁴

Standards for compression bandages

There is currently only the British standard, (BS) 7505:1995, for compression bandages. It contains four categories of compression bandages,⁷² which are summarized in Table 6.4.

Table 6.4 Classification of compression bandages by British Standard⁷²

By definition, the indicated pressure levels should be achieved on an ankle 23 cm in circumference, when applied with a 50% overlap. This classification was constructed entirely based on in vitro measurements and does not correspond to the clinical reality, according to which the resulting pressure of a bandage mainly depends on the sretch during application and far less on the material. Only a few measurements of compression pressure on the human leg have been reported, applying different materials with light, moderate, and high strength.⁸⁵ It could be demonstrated that the interface pressure of a bandage on the human leg was, on average, one class higher compared with the values in Table 6.1 for compression stockings. Even with intentionally very loose bandaging in an attempt to achieve ‘light compression’, the pressure of the 5-m-long bandage, short stretch and long stretch, was always higher than 20 mmHg with one bandage and higher than 30 mmHg with a multilayer technique.

Because of these dicrepancies, new proposals concerning a bandage classification were made in a consensus conference based on practical measurements in vivo.⁷⁰ The eponym ‘PLACE’ was proposed, containing the main characteristics to be considered when compression bandages are applied: P stands for pressure, LA for layers, C for components and E for the elastic property of the single bandage used. Table 6.5 shows the definition of different pressure ranges. Bandages are always applied with some overlap so that one layer bandages do not exist. The only one layer system is a compression stocking. Actually, the so-called four-layer bandage is applied with much more than four layers and should correctly be called a ‘four-component bandage’ since it contains four different bandage materials. It was proposed to use the terms ‘elastic’ and ‘inelastic’ only for single bandages based on their elastic properties, but not for a final bandage consisting of different single bandages. In fact, the elastic property of the final bandage cannot be predicted based on the elasticity of the single components. Adding several bandages does not only increase the sub-bandage pressure but enhances the stiffness of the final bandage as well.

Inelastic and short-stretch bandages

Bandages with an extensibility close to zero, such as zinc paste (Unna boot) and rigid Velcro-bands like Circ-Aid (CircAid Medical Products, San Diego, Calif.) or Hydroboot, (Incappe Inc, Brandon, Miss.) are examples of completely nonelastic material. Nonelastic bandages must be applied with skill and some knowledge. If light compression is indicated they should be applied without extension of the fabric by moulding the material to the leg without tension. When strong compression is indicated, completely rigid zinc paste bandages need to be applied with full extension of the material and adjusted to the configuration of the leg. Figure 6.16 shows a bandage applied with zinc paste on the lower leg, wrapped over with a short-stretch bandage and with adhesive bandages over the knee and thigh of a patient with a proximal deep vein thrombosis (DVT).

Fig. 6.16 Inelastic compression bandage with high stiffness consisting of a tightly applied zinc paste bandage, wrapped over by a short-stretch cotton wool bandage on the leg and of adhesive bandages over the knee and thigh in a patient with an acute proximal deep vein thrombosis. The initial interface pressure on the lower leg is between 50 and 60 mmHg in the supine position.

Short-stretch bandages can be extended 30% to 100% and should be applied with a pressure of more than 50 mmHg on the distal leg if strong compression pressure is indicated. Due to an immediate removal of edema, this pressure will fall down to pressure values which are also well tolerated in the supine position. After some hours they have a low to slight resting pressure but still a high and very effective working pressure. Short-stretch bandages exert little pressure when the calf muscles are relaxed but prevent expansion in calf diameter when the muscles are contracting during standing and walking (‘high working pressure’). They are, therefore, comfortable when patients are recumbent, and they act to decrease venous pressure with ambulation.³⁷ The main disadvantage is that they may become loose after a few hours of wear, especially when applied too loosely. In immobile patients, correctly applied short-stretch and inelastic bandages are even more effective than long-stretch material. Even minimal toe movement or passive ankle mobilization performed by physiotherapists will produce a much higher massaging effect compared to elastic material.

Nonelastic bandages made of cotton may be washed and re-used. Another category of short-stretch material is the cohesive or adhesive bandage. A cohesive bandage sticks only to itself, and not to skin or hair, whereas an adhesive bandage also sticks to the skin. These bandages cannot be reused after removal.

Stiff bandage material is not easy to handle. Most untrained persons apply inelastic bandages with too low a pressure. In order to obtain a resting pressure on the distal leg of about 40 mmHg, the initial pressure after application should reach about 60 mmHg. As can be seen from the example in Figure 6.17, the resting pressure in the supine position drops from 70 mmHg to 50 mmHg after 2 hours. This pressure exerted by an inelastic bandage is also well tolerated during night time. However, there is less pressure loss in the standing position, so an effective range of pressure values is still maintained after 24 hours (see Fig. 6.17). Especially in the first days after bandage application, the reduction of swelling may be so pronounced that the bandages will get loose and have to be renewed. When edema reduction is stabilized, inelastic bandages may stay on the leg for several days.

Figure 6.17 Interface pressure exerted by a multilayer short-stretch bandage (Rosidal sys, Lohmann) measured by an MST tester¹¹⁹ on the medial leg in the supine (A) and in the standing position (B). Measuring points: B = behind the inner ankle, B1 = 8 cm above, C = 19 cm above, D = 27 cm above the ankle. The pressure drop of this multilayer short-stretch bandage is more pronounced in the supine than in the standing position.

A study of elastic, minimal-stretch, and nonelastic orthoses (CircAid), demonstrated that 4 hours after application, elastic bandages had 94% of their initial pressure, compared with 70% for minimal-stretch and 63% for the nonelastic orthoses.⁸⁶ In the supine position, the decrease at 4 hours was 72% for elastic, 59% for minimal-stretch, and 44% for nonelastic compression. One of the advantages of this particular orthosis is the fact that it can be readapted by the patient when it gets loose (Figs 6.18 and 6.19). Smaller but significant decreases in pressure under short-stretch bandages were also found in studies on changes in pressure with exercising.^87,88 Measurement of compression after walking for 3 hours and then again 7 days later showed a decrease in pressure from 80.5 mmHg to 43.6 mmHg after 3 hours and to 26.3 mmHg after 7 days. In this study, Comprilan (Beiersdorf, Germany) with an extensibility of 70% was used.⁸⁷ In the second study, elastic bandages did not demonstrate a similar degree of compression loss after tip-toe exercise.⁸⁸ Although the authors speculate that the loss in pressure during exercise may be related to application technique of the short-stretch bandage with a maximum tension of 45% (Compridur, Beiersdorf, Germany), this could also be explained by an immediate volume reduction of the leg as shown in healthy volunteers and in lymphedema patients (Rosidal sys and Rosidal Lymphset, Lohmann & Rauscher, Germany).⁸⁹

Figure 6.18 CircAid (San Diego, Calif.) ready-to-wear compression garment, Flex model.

Figure 6.19 CircAid (San Diego, Calif.) ready-to-wear compression garment, Standard model.

When the bandage gets loose, it should be renewed in order to prevent refilling of the extremity with edema and to avoid tourniquet effects from the down-gliding compression material. In patients with lymphedema who are best treated with short-stretch bandages in the initial phase, this may be necessary once a day.⁹⁰

Main indications for inelastic and short-stretch bandages are venous and mixed arteriovenous leg ulcers, DVT, superficial phlebitis, compression after surgery, sclerotherapy or endovenous therapy of varicose veins and lymphedema.

Elastic, long-stretch bandages

Elastic bandages or compression stockings are usually applied in the morning, preferably before getting up, and are removed before going to bed at night. These highly extensible devices are relatively easy to apply and accommodate changes in leg geometry, expanding and contracting during walking. They sustain applied pressure for extended time periods but may cause unpleasant feelings in the resting sitting or lying position.

Long-stretch bandages can be extended 140% to 200% and thus have a high resting pressure; that is, they exert pressure on the superficial venous system when the limb is at rest with a decreased working pressure as compared with short-stretch bandages (see Fig. 6.15). Because of their intrinsic high resting pressure, they can damage arterial, lymphatic, and venous flow if not applied carefully, so they are best used while patients are ambulatory. Their advantage is that they may be more easily molded around the heel and ankle and can sustain their pressure better than inelastic bandages.

Elastic leg compression applied over a long period in the recumbent position may impede microcirculation and jeopardize tissue viability. New materials have been developed which provide effective compression pressures for a wide range of varying stretch. They are applied as multilayer bandages and may stay on the leg for several days and nights (Proguide, Smith & Nephew, UK).

Such bandages can be used to maintain a decongested condition when inelastic bandages are no longer required and may replace elastic stockings if these cannot be put on.

Multilayer bandages

In the above-mentioned consensus paper it is stated that ‘multilayer bandages’ are actually multicomponent bandages consisting of different materials for padding retention and compression.⁷⁰

From these definitions it is quite obvious that many combinations of different materials are possible, which will lead not only to an increasing pressure with each layer but also to variable elastic properties of the final bandage. In a comparative trial with different brands of four-layer bandages it was found that, in fact, a bandage applied as part of a multilayered system achieves only about 70% of the pressure that it exerts when applied alone, thus challenging the commonly held assumption that the final pressure achieved by a multilayer bandaging system is the sum of the pressures exerted by each individual layer.⁹¹ The elastic property of the final bandage will change toward a more inelastic bandage due to the friction of several layers, so that it can also be tolerated in the supine position⁹² (Fig. 6.20). One example is the so-called four-layer bandage which consists of several components of different material (wool, crepe, elastic and self-cohesive) and which may be worn day and night (Profore, Smith & Nephew, Hull, UK).

Figure 6.20 Hysteresis curves of different bandage materials. A, To achieve the same pressure level on the leg (blue dashed line) elastic bandages (right) need more stretch than inelastic (left). B, Compared with one layer of elastic material (right), two layers lead to a shift of the hysteresis curve towards the left. The elastic property of the final bandages is similar to a short-stretch bandage (top).

(Redrawn from Partsch H, Rabe E, Stemmer R. Compression therapy of the extremities. Paris, 1999. Editions Phlébologiques Francaises.)

It had been claimed that such bandages have not lost pressure at 1-week follow-up.⁹³ Actually some of our own measurements revealed a pressure loss starting immediately after application which is less pronounced compared to short-stretch bandage systems.

One study compared eight different compression bandages under standardized conditions.⁹² Multilayer bandage systems composed of short and medium stretch bandages exhibit the smallest pressure loss with patient activity and have a significant pressure decrease when the patient is supine. These systems gave better postural and interface pressure changes than all types of single-layer bandages, obviously due to an increase of the stiffness of the final multilayer bandage.^79,85

There are also multilayer systems consisting of short-stretch material, which are equally effective in ulcer healing when applied correctly.^94,95 Examples are the Pütter bandage (Hartmann, Germany), Rosidal sys (Lohmann & Rauscher, Germany), the adhesive Actico bandage (Activa Healthcare, UK), the Coban 2 bandage (3M, Minnesota, USA) and the Fischer bandage, consisting of a tightly applied Unna boot with a short-stretch bandage on top. This latter bandage was recommended by Heinrich Fischer, the pupil of Unna, in 1910 for the treatment of DVT⁴ and is still one of the author’s favorites in patients with DVT, post-thrombotic syndrome, or venous leg ulcers (see Fig. 6.16). The tradition of using multilayer short-stretch bandages is rather restricted to central European countries and to the Netherlands, while many bandagers in the UK are more familiar with multilayer systems containing rather long-stretch material.

Several trials have compared multilayer long-stretch bandages with short stretch, some showing better results with the short stretch,^94,95 some with long-stretch multilayer systems.^96,97 Frequently unfair comparisons have been made comparing properly applied versus inadequately applied bandages. In future trials, sufficient training of the bandagers should be provided for both systems and interface pressure and stiffness should be measured.

One advantage of the multilayer bandages composed of short-stretch material is their reusability, in contrast to the single-use elastic multilayer systems. Short-stretch cotton wool bandages get stiffer with each washing procedure.

The principle of applying several compression layers over each other is also a promising concept for elastic stockings, with regards to an increase in both compression pressure and stiffness.^98,99

Training in the application of bandages

A major drawback of bandages is their non-uniform application. A comparison of the range in pressures measured during application of a long-stretch elastic bandage by skilled nurses versus nursing students demonstrated that the skilled bandager’s pressure ranged from 25 to 50 mmHg, and the unskilled bandager’s pressure ranged from 15 to 70 mmHg.¹⁰⁰

A recent study checking the sub-bandage pressure showed that especially nurses with long professional experience tend to apply short-stretch bandages much too loosely (< 20 mmHg) and that this can be greatly improved by training.¹⁰¹

Several elastic bandages are marked with geometrical figures, such as a rectangle that becomes a square when stretched to the proper length (e.g. Setopress, Seton Healthcare Group, Oldham, UK; Proguide, Smith and Nephew, UK; Velpeau, Lohmann & Rauscher, France) (Fig. 6.21). Setopress was studied in five skilled nurses and five unskilled assistants, who also applied an Elastocrepe (Smith and Nephew, UK) bandage to the opposite leg. The Setopress bandage applied by experienced nurses most closely approximated target sub-bandage pressures whereas the unskilled group differed significantly among themselves. As before, both groups differed significantly in applying sub-bandage pressure with the Elastocrepe bandage, with a significant difference noted between the skilled nurses and unskilled bandagers.¹⁰² An additional study of 18 nurses applying an adhesive compression bandage showed 10 nurses producing a tourniquet effect, 5 producing inadequate ankle pressure, 2 excessive ankle pressure, and 1 appropriate ankle pressure but with an improper gradient in the calf.¹⁰³ Training significantly improved performance. Another study of 48 trained community nurses that compared one inelastic and two elastic bandages showed similar results.¹⁰⁴ The most common problem was production of a calf tourniquet.

Figure 6.21 Appearance of a 30-mmHg, medium-stretch compression bandage without tension (Setopress, Seton Healthcare Group, Oldham, UK). A, Note rectangular boxes. B, Same bandage stretched to provide approximately 30 mmHg compression. Note that the rectangular boxes have now assumed a square shape.

In addition, even with physicians who are experts in applying bandages, a true graduation in pressure may not always be obtained. One study of five surgeons showed a range of 21.9 to 52.7 mmHg with application of a short-stretch bandage, with each individual surgeon having a range of 10 to 20 mmHg between bandage applications.¹⁰⁵ The coefficient of variation in each individual ranged from 9.9% to 25.2% with a mean (standard deviation) of 17.0 (4.9%).

Based on the information just presented, it is obvious that training in the application of bandages is very important.^101–107 This is especially true for inelastic bandages, which should be applied with a higher initial pressure compared to elastic material. Instruction of compression application with the use of interface pressure measurement has been shown to improve technique.¹⁰⁷ In teaching 156 persons at a wound healing course, the application of appropriate interface pressures required approximately 10 exercises with the use of interface pressure transducers.

Important points to consider when applying a bandage are:

Compression bandages or compression stockings?

In general, compression bandages are able to achieve higher pressure than compression stockings.⁸⁵ Therefore, in severe stages of venous disease, treatment may be initiated with compression bandages.

Bandages are best indicated when temporary compression is required, such as in the acute phase of DVT, superficial phlebitis, in patients with venous ulcers, and in lymphedema and phlebolymphedema. As soon as the inflammatory signs and symptoms and the swelling are improved, compression stockings should be used to maintain the effect. Another benefit of bandages is that they can be reapplied as necessary as the edema in the affected limb is reduced. In this way, the optimum compression needed for efficient therapy is obtainable.

Varying the strength of wrapping will alter pressure. The elasticity of bandages, although limited, changes somewhat according to the type used and functions as a fixed support. Stockings, however, with elastic properties and graduated pressures fixed at the time of manufacture, undergo no change until the stocking is worn out and no longer usable. In fact, stockings must be made of highly elastic materials to enable them to be pulled over the heel of the foot.

Elastic, long-stretch bandages and elastic stockings may be handled and reapplied by the patients daily. Usually they are removed overnight. In contrast, Unna boot bandages and short-stretch bandages stay day and night on the leg and should be changed by the bandager every few days. When they get loose, they may be wrapped over by the patient, preferably using washed short-stretch bandage.

Multilayer bandages consisting of several layers of long-stretch material obtain the elastic property of short-stretch bandages (see Fig. 6.20) and may also stay on the leg for several days.

Table 6.6 gives an overview of some practical characteristics of different products.

Characteristics of medical graduated compression stockings

Most compression stockings are more or less two-way stretch stockings – elastic in both the longitudinal and transverse directions. This provides the stretch needed to apply a stocking that has the smallest diameter at the ankle to be drawn over the heel. Two-way stretch stockings also have the characteristics of longitudinal bandages. The longitudinal elasticity of the stocking compensates for differences in limb length, thereby facilitating joint movements. In addition to the compression generated by the stocking, another important parameter is the stiffness, elasticity or slope value of the stocking.

Ready-made stockings

Ready-made or off-the-shelf stockings are manufactured in fixed sizes. Most manufacturers have several sizes, varying in both length and width at various points on the ankle, calf, and thigh (Fig. 6.24). Although the sizes are standardized to some degree by associations of stocking manufacturers, such as the Gütezeichengemeinschaft Medizinischer Kompressionsstrümpfe e.V. (Quality Seal Association for Medical Compression Stockings) in Germany,⁷³ there may be considerable variation between the sizings of different manufacturers. Therefore it may be prudent for distributors and physicians who dispense stockings to carry multiple brands in the event that some patients experience a poor fit with certain makes. It may be estimated that 80% to 90% of patients seeking treatment for venous disease can be fitted with some form of ready-made stockings.

Figure 6.24 Six types of graduated compression stockings widely available.

(Courtesy of Juzo.)

Custom-made stockings

Made-to-measure stockings are custom-made according to the length and circumference measurements of the patient’s leg. Adjustments are made either by hand on flat-knitting machines, in which shaping is achieved by altering the width of the knit, or by machine in a circular-knit manner, in which changes in the pressure and width are achieved by varying the tension of the weft and stitch size. Flat-bed knitted hosiery comes with a seam. Round-knitted stockings are seamless and can also be made to measure. For a good fit, it is essential to get precise and accurate measurements of the patient. Custom-made garments will fit better than ready-to-wear. Several companies provide garments from woven fabric for patients of all body shapes and required compression levels.

Made-to-measure stockings should be prescribed under the following circumstances:

Prescription of a stocking

Individual measurement of a compression stocking should be taken at the beginning of the day, when the leg is less edematous in the standing position. The most important measurement location is at the ankle, where a graduated stocking exerts the greatest degree of pressure. Therefore, all ready-made stockings include this as one of the measuring points. Measurements taken at various levels of the calf and thigh must also conform to the manufacturer’s guidelines. If a calf or thigh diameter does not conform to the manufacturer’s guide for that particular stocking size then a made-to-measure stocking should be used.

Recently, a biometrical scanner combined with an ‘intelligent ordering system’ was introduced by the Bauerfeind company. Instead of measuring the leg circumference with a tape, digital photographs of the legs are taken against a structured background, which are then sent to the manufacturer for the production of a stocking to fit that individual.

A common error made by the physician to avoid prescribing a made-to-measure stocking is that of prescribing the next larger size of a ready-made stocking. This results in a lower pressure being exerted at the ankle; in addition, the counter-pressures are altered because the wider stocking is designed at all levels for different leg measurements. Proper measurement and fit of a compression stocking becomes increasingly important when higher compression classes are required. Therefore, made-to-measure stockings have particular application for compression classes above 40 mmHg, as used, for example, in lymphedema.¹¹⁵

The physician should note that differences of more than 15 mmHg could occur among different stocking manufacturers, not only by virtue of different types and strengths of elastic materials, but also by different methods of measuring the stocking to fit the leg. Some manufacturers provide only three ankle sizes of stockings, whereas others provide up to six or more ankle sizes. Thus, there may be a large variation of applied pressure for different-sized legs among different stocking brands, as dictated by Laplace’s law.

All manufacturers of compression stockings use a ‘standard’ wooden leg (the so-called Hohenstein leg), whose circumferences in each segment are circular.¹ This is also true for the B segment (see Fig. 6.11), representing the ankle area, which is taken as the reference point for indicating the pressure class of the stocking. In real life, this B segment is the area in which the cross-section through a human leg shows the most extensive deviations from a circle.⁸⁰ Here, the radius varies dramatically, being small over the malleoli and the Achilles tendon and even ‘negative’ between the inner ankle and the tendon. According to the law of Laplace, the compression pressure will therefore also change considerably, which explains the discrepancy between in vitro and in vivo measurements of interface pressure especially in this segment. However, a good correlation could be shown between the pressure ranges declared by the producers of high-quality stockings and the actual interface pressure exerted on the human leg.¹¹⁶

Stocking lengths

Up to six styles of medical compression stockings are available, depending on the manufacturer: knee-length, mid-thigh or high-thigh pantyhose or leotard, one-legged pantyhose, thigh with waist attachment, and maternity pantyhose. Some manufacturers have open-toed kinds available for some of the types, especially the single leg, high-thigh variety. Regardless of the style, most stockings are available in three lengths: knee length, mid thigh, and high thigh. According to the standardized figure, a knee-length stocking is designated as ‘AD’, a mid-thigh stocking as ‘AF’, and a (high) thigh-length stocking as ‘AG’ (see Fig. 6.11).

There are specific indications and contraindications for the various stocking lengths. Knee-length stockings should be prescribed only if the ‘C’ circumference is approximately 2 cm greater than the ‘D’ circumference; otherwise it will have no hold on the leg and tend to slide down. In addition, if the ‘A to D’ length is too great, the excessive length interferes with movement at the knee. The patient usually folds the excess stocking down below the knee; this doubles the counter-pressure at point ‘D’ and thus may reverse the ‘graduated pressure’. Likewise, if the ‘A to D’ length is too short, the patient will try to stretch the stocking beyond its natural point, thereby decreasing the effective circumferential pressure and thus defeating the purpose of wearing the stocking.

In patients with marked adiposity of the knee region, the upper edge of the stocking may produce skin bulging, which may be particularly bothersome on the inner aspect of the knee. In these cases, it may be necessary to fit the patient with a mid-thigh stocking. Alternatively, tumescent liposuction of the bulging knee corrects this deformity and is a simple procedure.

In order to prevent or treat ankle edema or skin changes due to CVI, the majority of patients can be fitted with below-knee, ready-to-wear stockings.

Pressure gradient

Graduation is not only a result of the leg circumference, it can also be added to a circular knit by altering the knitting construction from the ankle to the knee or thigh to reduce the tension from distal to proximal. Some studies have demonstrated that a pressure drop of 26% to 59% from the ankle to the thigh is desirable with graduated medical stockings.^117–119

As previously explained, it is postulated that compression of the leg should be applied in a graduated manner to ensure and aid the optimal unidirectional flow of blood toward the heart and to avoid a proximal tourniquet effect. The measurement of an ideal pressure profile on the human leg depends on several factors, especially on the shape of the measuring point.¹²⁰

It has to be considered that the pressure gradient postulated for compression hosiery is based on pressure readings on the smallest segment of a wooden leg model in the laboratory (B-point) presenting a circular cross-section. Owing to the fact that the human leg is flat or even concave at the corresponding medial ankle region, in vivo measurements at this point frequently show lower pressure values than at the B1-point 12 cm above (see Fig. 6.17).

There are many situations for which the dogma of a pressure gradient is unrealistic. Due to the changes of segmental circumferences and local curvatures that happen with every step, the local dynamic pressure fluctuations under a compression device may be very complex, and pressure peaks may occur which are higher at a proximal level than distally. In general, the necessity for a continuous gradient of pressure maximal at the ankle and diminishing up the limb is founded more on theory than on an evidence base.

New stockings have been introduced that exert a higher pressure over the calf than over the ankle area. These are easier to put on and are not only advocated in sports¹²¹ but also in venous patients.¹²²

Proper fit and position

Because the efficacy of a compression stocking is directly related to a proper fit, its adherence to the leg to prevent vertical movement is important. Pantyhose stockings are the most expensive method to ensure the stocking remains in place by virtue of the attachment at the panty line. The only disadvantages are increased constriction on the lower abdomen and increased temperature and moisture retention in the groin generated by an additional undergarment.

With single-leg, thigh, or calf stockings, various inexpensive methods, such as adhesive tape, glues, clips, or garter belts, serve to ensure proper positioning. Disadvantages of tapes or glues include the pain on removal of tape from hairy legs and the irritation of allergy caused by the adhesive portion of the tape. Various types of clips that secure the stocking to underwear are available. Disadvantages include tearing or stretching out the undergarment and cutaneous pressure and/or irritation by the clip itself.

Garter belts comprise a more elegant, practical, and perhaps fashionable method for ensuring correct stocking placement. These belts may be built into the stocking as a waist attachment or purchased separately in various styles. Disadvantages include the digging in of the belt into an obese thigh if the belt is too narrow and the possibility of the garter itself producing a tourniquet effect.

Finally, a new type of silicone top-band on high-thigh- or mid-thigh-length stockings is available from many manufacturers of graduated compression stockings. It keeps the stocking in place without the disadvantages of glues, clips, or garter belts.

Donning medical compression stockings

Before donning the stocking, the patient should be advised of the following considerations. Hand jewelry should be removed to avoid damaging the stockings. Fingernails should be smooth and relatively short. Rubber gloves are helpful and recommended both to prevent damage to the stockings from long fingernails and to grip the stocking. Talcum powder may be applied to the leg, or a light Perlon pantyhose or stocking may be worn under the compression stocking, to create a smoother leg over which to slide the stocking. Finally, satin foot ‘socks’ and foam-rubber foot pads provided by the stocking manufacturer are helpful in getting an open-toe stocking over the ankle (Fig. 6.25).

Figure 6.25 Foot sock, which is helpful for getting an open-toed stocking over the ankle.

After preparing the foot and leg, turn the stocking inside out with the foot from the heel to the toe tucked into the stocking (Fig. 6.26A). Stretch the foot opening with the fingers or thumbs of both hands and pull the stocking foot over the foot up to the instep. Draw the stocking upward over the heel until pulling becomes difficult (Fig. 6.26B). Push the fold that forms across the instep and heel of the stocking over the heel. Finally, pull the stocking up in sections, always remembering not to pull it over long distances all at once but to proceed in small steps (Fig. 6.26C). When the stocking is applied without folds over the calf, the thigh section is then pulled over the knee (Fig. 6.26D). Finally, remove the foot ‘sock’ (Fig. 6.26E).

Figure 6.26 Schematic diagram illustrating the proper method for donning the compression stocking. A, Turn the stocking inside out. Tuck in the foot from the heel to the toe. B, Using both hands, pull the stocking over the foot up to the instep, drawing it upward over the heel. C, Continue pulling the stocking up in small sections. D, Pull the thigh section over the knee. E, Remove the foot sock.

(Courtesy of Juzo.)

It is very important for the physician or nurse to instruct and observe the patient applying the stocking. Compression is effective only when a stocking that has been fitted correctly and is applied correctly. If the patient encounters difficulties in applying the stocking because of age, obesity, arthritis, etc., arrangements should be made to have an experienced helper on hand when needed. It is important to note that if patients have difficulty in applying higher-compression class stockings, wearing two layers of lighter stockings, one over the other, should be helpful. As discussed previously, the compressive effects of stockings are additive and stiffness increases exponentially. Zippers in stockings (available on some calf-length stockings) also make donning them easier.

An application aid for compression stockings is also available from various compression stocking companies. These devices are cleverly designed, simple metal supports that make donning compression stockings easier, even when the stockings must be placed over compression padding (Fig. 6.27). The compression stocking is pulled over the half-circle bracket located on the front (open) side of the device so that the heel portion of the stocking is 2 to 3 inches (about 5–7.5 cm) below the top on the half-circle bracket. The heel portion is positioned facing the user, and the toe of the stocking is facing toward the open side of the device. The patient’s foot is then placed into the foot of the stocking until the foot is completely on the floor or until the heel is in place. The metal grips on either side are then used to pull the rest of the stocking onto the leg. Once the stocking is above the calf, the device may be pulled away and the remainder of the stocking then can be easily pulled up.

Figure 6.27 Medi Butler. A, After putting the compression stocking on the bracket, insert the foot. B, Continue until the foot is completely on the floor and the heel is in place. C, Pull up on the metal side grips until the Butler is above the calf, then remove it and continue until the stocking is in place.

(Courtesy of Medi USA, Whitsett, N.C.)

Patient compliance

Noncompliance is the most important factor limiting the use of compression stockings. The reasons for noncompliance can be grouped into two interdependent major categories: (1) wear-comfort factors and (2) the intangible sense of restriction imposed by the stockings.¹²³

In addition to a measurable improvement in multiple parameters of CVI, a study on symptoms of CVI has demonstrated an improvement after 1 and 16 months of wearing graduated compression stockings.¹²⁴ In this study, 112 patients with CVI and significant CEAP classification (clinical state [C], etiology [E], anatomy [A], and pathophysiology [P]) were treated with a 30- to 40-mmHg graduated compression stocking. Patients rated on a five-point scale the degree of swelling, pain, skin discoloration, cosmetic problems, activity tolerance, depression, and sleep problems caused by CVI. There were statistical improvements in all scores at 1 month, with continued improvement at 16 months. Most importantly, 70% of patients were still wearing their stockings at 16 months, demonstrating their comfort over the symptoms of CVI. This is in contrast with the impression of poor compliance and indicates improved comfort with modern compression stockings. Similar degrees of improvement were also demonstrated in 31 patients with CVI wearing low- or medium-grade stockings.¹²⁵ There was no significant difference in symptoms in these patients despite the difference in graduated compression. Therefore, patients who cannot tolerate class II stockings should be fitted with class I stockings. Mild compression is better than no compression.

Patients’ compliance in wearing their compression stockings is frequently underestimated by the physicians. In a Canadian survey, physicians estimated that 50% of patients after DVT would wear compression stockings daily, 30% occasionally, and 20% would never wear them.¹²⁶ In this study the most important reasons for noncompliance were thought to be discomfort (74%), hard to put on (71%), and high costs (53%). When the patients were asked, daily use was reported by 87%, once or twice weekly by 3%, less than once a week by 6%, and never or rarely by 4%. In a European follow-up of patients, it was shown that there is less swelling of the thrombosed leg when the stockings are still being worn 2 years after DVT compared to in those patients who stop compression therapy before this time and that most of those patients who still suffer from pronounced residual swelling use them.¹²⁷

Care of the medical compression stocking

Because these stockings are worn on a daily basis in extremely close contact with the skin, they are subjected to considerable wear and tear. The chemical stresses from sweat, soaps, creams, and body oils, in addition to the physical stresses of the nearly continuous stretch and relaxation with movements of the leg, result in a gradual decline in the compressive effect of the stockings. This decline was measured in class II and class III stockings. Flat-knitted and round-knitted European class II stockings showed a mean pressure decrease from 29.3 to 26.5 mmHg after 3 months of daily wear. Strong stockings had a similar rate of decreasing pressure from 47.5 to 44.2 mmHg.¹²⁸ Compression stockings, therefore, have a limited effective life. To ensure that they last as long as possible, special care is required.

The first lesson in proper stocking care is to avoid excessive trauma. Therefore, rubber gloves should be worn when the stocking is put on, to avoid tearing the threads with fingernails. Likewise, toenails should be trimmed, and hard calluses, verrucas, or other rough spots on the feet should be softened or removed. Also, the stocking should be eased onto the leg, not pulled.

The stocking should not come into contact with ointments, creams, stain removers, or other solvents, especially if it is composed of rubber threads. These substances can damage the fine elastic yarns by causing them to swell, thus reducing the strength and elasticity of the fabric. Some chemical components of topical steroid creams (chlorocresol and glyceryl mono-oleate) may have a negative influence on Lycra yarns, causing a decrease in elasticity as well as discoloration.

Regular and careful washing is necessary to maintain the elastic properties of the fabric. This is because of the harmful effects of sweat, skin oils, and environmental dirt that accumulate in the fabric while the stocking is worn. These substances will penetrate deeper into the elastic yarns if allowed to remain on the fabric for long intervals between washings. Environmental dust is damaging to the yarn by virtue of its abrasive action when the elastomers are stretched and relaxed.

Ideally, compression stockings should be washed every day. In fact, a study of six stocking types machine washed 15 times at 40°C demonstrated no decrease in resting pressure or elasticity.⁹³ Therefore, if long-term use is required, it is best to provide the patient with two pairs of stockings that can be alternated between washings. Most compression stockings incorporating spandex can be machine washed on a fine-gentle cycle with warm (40°C) water. This gives a better cleansing action than hand washing. (Consult the manufacturer’s guidelines for specific instructions.) Gentle detergents without bleach or alkali are best. Gentle spinning after the washing cycle is harmless to compression stockings and quickens the drying process. Rather than being hang-dried from a line, compression stockings should be laid flat on a drying rack or towel. Low heat may be used in the drying process with most brands of compression stockings. With normal wear and proper care, compression stockings should have an effective life of 4 to 6 months.

If compression stockings are worn intermittently (during airplane flights or only after sclerotherapy or surgical treatments), they should be stored in a cool place after washing. Exposure to heat for prolonged periods can degrade the yarn and eliminate compression.

How much pressure is necessary for varicose veins?

The optimum interface pressure required to compress the varicose vein after sclerotherapy has yet to be defined.

Initial compression measurements taken during manual wrapping of the leg with Crevic crepe bandages by multiple surgeons using the technique of Fegan¹⁴⁰ show an average between 20 and 100 mmHg with a mean of 54 mmHg at calf level.¹¹⁷ In addition, experimental varicose vein models have shown this level of compression to cause a reduction of the vessel lumina by 94%.¹¹⁷ Thus, the classic technique for compression sclerotherapy is theoretically sound.

The physician should consider the posture of the patient when prescribing compression stockings. If higher compression pressures are used (e.g. through the use of double stockings), care must be taken to inform patients to remove the outer stocking when not ambulatory. A sustained external pressure above 30 mmHg with elastic material applied to the leg of supine patients may impair peripheral blood circulation and skin temperature.¹⁰⁰ Patients may perceive this as achiness in the ankle area that occurs during sleep and resolves with walking after 30- to 40-mmHg compression stockings have been worn to bed following sclerotherapy.

By having compression of 30 to 40 mmHg at the ankle, the compressive strength at other locations on the leg may be between 10 and 20 mmHg, depending on the site and amount of underlying bone, adipose tissue, and muscle.³¹ Experimental models have demonstrated that external pressures of 10 to 15 mmHg reduce the capacity of the underlying varicose vein only minimally.^21,39,117 Therefore, with the use of this degree of compression, one does not attempt to completely empty intravascular blood from the treated veins.

Local pads and rolls

In order to occlude a vein completely, the external pressure should exceed the intravenous pressure. In the standing position, the intravenous pressure is about 70 mmHg at the lower leg and about 30 mmHg at thigh level, depending on the body height. The pressure exerted by a compression stocking at thigh level is about 10 to 15 mmHg, which is too low to occlude the vein.^21,110

By applying small rolls with different materials over the injected vein, this difficulty may be overcome, as demonstrated in Figure 6.30. When the injected vein is covered by a small rubber roll, a thigh-length compression stocking with a pressure of 15 to 20 mmHg may compress the vein even in the standing position.

Figure 6.30 A blood pressure cuff (‘RR cuff’) is applied on the thigh and inflated in a stepwise fashion from 20 to 60 mmHg (x axis). The local pressure over the great saphenous vein is measured using a small Kikuhime pressure transducer (MediTrade, Soro, Denmark), which is placed under a 2-cm-thick gauze roll (top) and then under a rubber roll with the same dimension (bottom). With the soft padding material (top), the local pressure over the vein (y axis) can be doubled; with the rubber pad (bottom), a cuff pressure of 20 mmHg will increase the local pressure under the pad close to 60 mmHg.

The increase of pressure in a localized area by using narrow foam rubber pads under compression stockings has been described by several authors.^151–156 Foam Sorbo pads (STD Pharmaceuticals, Hereford, England) (Fig. 6.31) are widely used in Great Britain.¹⁴³ A new wedge-like rubber foam device (postop device, Medi, Bayreuth, Germany) has been developed specifically for compressing the great saphenous vein on the thigh (Fig. 6.33) and a very satisfying outcome after stripping operation was reported.⁴⁵

Figure 6.31 Foam Sorbo pads (STD Pharmaceuticals, Hereford, UK).

Figure 6.33 A, A flat piece of cotton wool is twisted into a firm roll with a diameter of approximately 2 cm. B, The cotton wool roll follows the course of the varicose vein and is secured to the skin with 5-cm-wide Leukopore bandage (BSN-Jobst, Charlotte, N.C.). C, Appearance after application of a 30- to 40-mmHg compression stocking. D, Appearance after stocking and cotton wool are removed in 2 weeks. Note compression of both the varicose vein and overlying tissues.

Figure 6.32 A wedge-like foam pad (Postop device, Medi, Germany) is attached to the thigh by crosswise taping after endovenous laser ablation of the great saphenous vein.

(Courtesy M. Lugli and O. Maletti, Modena, Italy.)

Different types of pads do provide different pressures. A study by Hirai et al¹⁵⁴ demonstrated pressure over the anterior tibia with a moderate-pressure stocking to be 20.3 mmHg without pads, 59.1 mmHg with a cotton pad or gauze pad, 73.5 mmHg with a foam rubber pad, and 76.5 mmHg with a hard rubber pad.

In addition to producing an increase in cutaneous pressure, their use, especially in the popliteal region, has decreased the incidence of abrasions from pressure stockings and tape, thereby improving patient comfort. In one physician’s practice,¹⁵⁵ foam rubber pads have been noted to produce minor skin irritation (erythema) in up to 28% of patients. Another device for increasing local pressure is Molefoam (Scholl UK). This product comes in sheets of 7-mm thickness that may be cut easily to size. The adhesive side is covered with paper that is peeled away. Molefoam has a decreased incidence of local irritation (14% versus 28% for Sorbo pads). One study that compared the efficacy of sclerotherapy with Sorbo versus Molefoam showed no difference between the two groups.¹⁵⁵

Another clever method for increasing local pressure is the use of rolls of cotton wool.¹⁵⁶ The roll is secured with a nonelastic material. This method is advantageous for compressing long lengths of veins. A study of 100 patients (120 legs) with varicose veins treated with sclerotherapy, followed with long cotton wool rolls under compression stockings, found good results in all patients.¹⁵⁶ Compression was given by a combination of European class I (daytime and night-time) and class II (daytime only) compression hosiery. Only three patients developed intravascular blood clots. The mean pressure under the pads was 84 mmHg (68–122 mmHg). In this study, cotton rolls and class I stockings were removed at 1 week and patients continued to wear class II stockings for an additional 3 weeks.

Local padding of the injected vein may considerably improve the emptying of the vein. Especially in the thigh region, a satisfactory compression of the veins by compression stockings may be a problem due to a markedly low pressure. In such cases, compression bandages with adhesive material applied over the local pressure rolls may be a good alternative.^45,157

How long should compression be maintained?

In addition to the degree of compression needed to effect optimal sclerotherapy, the duration needed to maintain compression is also open for debate.¹⁵⁸ The classic technique for sclerosis of varicose veins described by Fegan^140,141 and used by Hobbs¹⁵⁹ and Doran and White¹⁶⁰ is to continue compression for 6 weeks. This period was not arrived at randomly but through multiple histologic examinations of sclerotherapy-treated varicose veins at intervals of 30 seconds; 1 and 5 minutes; 12, 24, and 36 hours; 6, 8, 12, and 14 days; 3, 4, 7, 10, 16, and 20 weeks; and 0.5, 1, and 5 years.¹⁶¹ Fegan concluded that organization of the fibrous occlusion required at least 6 weeks. However, a randomized study found no difference in clinical results at 2 years when compression was maintained for 3 weeks as compared with 6 weeks.¹⁶² Thus, many phlebologists recommend a maximum of 3 weeks of compression for varicose veins.

A review on RCTs regarding this question was recently published.¹³³ Studies have shown that compression bandages maintain significant compression for only 6 to 8 hours while patients are ambulatory and lose up to 50% of their initial compression pressure in recumbent patients at 24 hours,¹⁵¹ thus questioning the rationale for prolonged use. After phlebectomy, bandaging for 1, 3, and 6 weeks did not show a difference in efficacy at 2 months postoperatively.¹⁶³ However, in this study, compression with an elastic bandage was given to all groups for only 1 week, with the variable being a Tubigrip tube gauze (Seton Products, Montgomeryville, Pa., USA) applied only during the day, which provided minimal compression. Finally, a randomized study of the use of compressive bandages in the treatment of varicose veins with a 3-month follow-up was reported.¹⁶⁴ The study demonstrated through both subjective and objective findings that 3 days of compression equaled the results at 6 weeks. This study used a Coban bandage dressing that may not maintain effective pressure beyond 8 hours.

A corollary to the amount of time necessary to effect adequate compression is whether it is necessary to continue compression while the patient is lying down or asleep. The authors recommend that some degree of compression be maintained at all times to ensure optimal contraction of the treated vein. In fact, studies have demonstrated that veins become more distensible during sleep.¹⁶⁵ This has been postulated to occur as a result of respiratory factors or emotional factors during dream states. In addition, thrombogenesis after the sclerotherapy-induced injury to vascular endothelium is maximal 8 hours after treatment, which may be when the patient wishes to lie down (see Chapter 8). Compression here speeds deep venous blood flow to prevent thrombosis in the deep system after treatment. Finally, it may be impractical for patients to remove and reapply the stocking at night if they must get out of bed for any reason. Therefore, if a high degree of compression is required after treatment, the use of double stockings appears practical, since one of the stockings can be removed while the patient is lying down.

Some anatomic sites necessitate inventive measures to effect compression of the underlying varicose veins. Perhaps the most difficult area to compress on the leg is the vulvar region. The authors have found the ‘vulvar pad’ described by Nabatoff,¹⁶⁶ as well as the V2-Supporter (Prenatal Cradle Inc, Hamburg, Mich.) described by Ninia,¹⁶⁷ to be useful in this area.

Especially in France, there are colleagues who do not perform any compression after sclerotherapy of large veins.¹⁶⁸ Based on a comparative study the general recommendation of using compression after foam-sclerotherapy of the great saphenous vein as a routine has recently been questioned.¹⁶⁹

Rationale for the use of compression in the treatment of telangiectasias

Although compression sclerotherapy is now standard practice in the treatment of varicose veins, its use in the treatment of smaller abnormal leg veins and telangiectatic ‘spider’ veins has never been adopted uniformly. Many European colleagues do not use any kind of compression after sclerotherapy of small veins.¹⁶⁸ However, the same justification for the use of compression in larger veins should hold true for its use in smaller veins. Convincing results from a randomized controlled study are favouring the use of compression 23 to 32 mmHg hosiery for 3 weeks after sclerotherapy of small veins.¹⁷⁰

Duffy¹⁷¹ has classified unwanted leg veins into six types based on clinical (and possibly functional) appearance (see Box 2.6). Types 1, 1A, and 1B are probably dilated venules, possibly with intimate and direct communication to underlying larger veins from which they are direct tributaries.¹⁷² Both Bodian¹⁷³ and de Faria and Moraes¹⁷⁴ have found on biopsy examination that such ‘telangiectasias’ are actually ectatic veins. Therefore, because a significant percentage of smaller spider veins occur in direct communication with larger varicose or reticular superficial veins, compression of the ‘feeder’ vein should decrease, if not eliminate, the blood flow to the smaller connected vessels. Thus, in addition to the effects of compression on the treated vessels themselves, compression of the entire leg should lead to a relatively stagnant blood flow in the feeder veins, which should allow for more effective endosclerosis of the treated vessel and a subsequent decreased risk of recanalization.

How much pressure is necessary to compress telangiectasias?

The only reported study measuring the pressure necessary to empty superficial ‘capillaries’ (telangiectasias) on the leg demonstrated that a sudden emptying of superficial cutaneous capillaries occurred between 40 and 60 mmHg at a point 5 cm above the medial malleolus while the patient was recumbent.¹⁷⁵ However, 80 mmHg was required to produce a complete emptying of blood with the patient in a standing position. This degree of pressure can be obtained with a bandage wrapped over a local pad but not with graduated compression stockings on areas of the leg above the ankle.

One limitation to the use of compression stockings in treating leg telangiectasias is the lack of complete emptying of the treated telangiectasias when only one stocking is used. Theoretically, the incorporation of foam pads directly over the injected vessels and a double layer of compression stockings for daytime use, with one stocking removed on recumbency, should produce a more complete vascular occlusion (Fig. 6.34).

Figure 6.34 A, Clinical appearance of venules and telangiectasia on the anterior thigh of a 42-year-old woman, measuring 0.2 to 0.6 mm in diameter, without evidence of an obvious feeding reticular or perforating vein. B, Immediately after sclerotherapy with polidocanol 0.5%, STD foam pads were applied over the injected veins and secured with Microfoam tape under a 30- to 40-mmHg graduated compression stocking. C, Three days after treatment, immediately after the removal of both the stocking and the pads. There is significant thrombosis of the treated veins even with a high degree of compression, as noted by the indentation of the foam pad on the skin overlying the vessel.

As shown in Figure 6.35 even very high pressure applied by a circular compression device is not able to compress small skin veins.

Figure 6.35 Using a blood pressure cuff with an acetate window (Echocuff, VNUS, USA) the effect of compression on the diameter of spider veins on the thigh was investigated. A, loosely applied cuff (6 mmHg), Fig. B, cuff inflated to 100 mmHg. The experiment shows that small skin veins cannot be compressed by circular compression devices.

(Courtesy B. Partsch, Vienna)

Based on serial biopsies performed by L. Wenner after sclerotherapy of small veins, Staubesand and Seydewitz were able to demonstrate by electron microscopy less thrombus formation using powerful local compression.¹⁷⁶

A multicenter, bilateral comparative study through the North American Society of Phlebology (now the American College of Phlebology) examined the necessity for the use of a class II (30- to 40-mmHg) single stocking when treating leg telangiectasias.¹⁷⁷ Thirty-seven women with bilaterally symmetric telangiectatic leg veins of less than 1 mm in diameter were evaluated. One set of vessels was compressed for 3 days with a 30- to 40-mmHg compression stocking (MediUSA, Arlington Heights, Ill.) over a cotton ball dressing. The alternate set of vessels had a cotton ball dressing applied for 2 hours with paper tape without an overlying compression stocking. With the stocking, a greater clinical resolution occurred after treatment with one sclerotherapy injection on vessels located on the distal leg, or when vessels were greater than 0.5 mm in diameter. Vessels located elsewhere or less than 0.5 mm in diameter showed no significant difference when this form of compression was used.

The main benefit of compression treatment was noted in the evaluation of adverse sequelae (Table 6.7).¹⁷⁷ The most significant finding in this study was that 20 to 30 mmHg compression produced a relative decrease in postsclerotherapy hyperpigmentation, which fell from an incidence of 40.5% to 28.5% with the use of compression. In addition, ankle and calf edema were lessened if a graduated compression stocking was worn immediately after sclerotherapy.

An additional, nonrandomized study of 386 patients with leg telangiectasias was conducted without bilateral paired comparison. In this study, 436 legs received graduated elastic stockings (compression class not stated) for 48 to 96 hours, and 182 legs were not compressed. Disappearance of more than 70% of telangiectasias occurred in one treatment in 85.7% of patients who wore compression stockings versus 72.5% of patients without compression (P < 0.01). In addition, compression reduced the incidence of pigmentation from 12.2% to 6.7%.

How long should compression be maintained after sclerotherapy of small veins?

Formal studies on the use of compression in the treatment of leg telangiectasias are rare. A 3-day period for compression of leg telangiectasias is common based on the empirical report of Ouvry and Davy,¹⁴⁷ who advised a minimum of 3 days to limit the development of peripheral inflammation and intravascular thrombosis. Without supporting information, Harridge¹⁷⁸ recommended a 1-week period of compression for spider veins, using a local pressure band of elastic adhesive only.

A review concerning compression and its effects on compression sclerotherapy of reticular and telangiectatic legs veins has been reported.¹⁷⁹ Forty patients were treated with sclerotherapy in three centers, followed by no compression or compression with 20- to 30-mmHg graduated stocking for 3 days, 1 week, or 3 weeks. A statistically significant improvement in hyperpigmentation and resolution was seen in patients treated with 3 weeks of compression. Patients treated with compression for 3 days or 1 week also had a greater degree of improvement than patients not treated with compression. Patients treated with compression for 1 or 3 weeks had the least amount of postsclerotherapy hyperpigmentation. The full benefits of compression were seen when patients were examined 6 months after a single treatment. The authors concluded that patients are best treated with either 1 or 3 weeks of compression after sclerotherapy, but that even 3 days of compression offers some improvement over no compression.

In another randomized controlled trial, the outcome of sclerotherapy with subsequent Elastoplast bandages was compared with the results after 35- to 40-mmHg stockings.¹⁸⁰ After 3 to 6 weeks, the stocking group showed a higher success rate, less thrombosis, and less pigmentation.