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The effects of elastic stockings on the venous hemodynamics of patients with chronic venous insufficiency *
(Portuguese PDF version)

Marcondes A. M. Figueiredo,¹ Augusto D. Filho,² André L. S. Cabral³

1. Angiologist and vascular surgeon, Uberlândia, MG, Brazil.
2. Associate professor, Department of General Surgery, Faculty of Medicine, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil.
3. Associate professor, Faculty of Medicine, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.

* This work is part of the thesis presented to Universidade Federal de Uberlândia, Faculty of Medicine, in fulfillment of the requirements for the degree of Master of Science in Medical Clinic.

Correspondence:
Marcondes A. M. Figueiredo
Rua General Osório, 544
CEP 38400-158 - Uberlândia, MG
Brazil
Phone: +55 (34) 3214.1885
Fax: +55 (34) 3231.3526
E-mail: marcondes@triang.com.br

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ABSTRACT

Objective: To asses the effects of elastic stockings (30-40 mmHg) on the venous hemodynamics of patients with chronic venous insufficiency by using an air plethysmograph.

Patients and method: 29 limbs in 16 patients (three men and 13 women), mean age 44.3 years. For the assessment of venous hemodynamic effects using air plethysmography SDV 2000 (Angiotec - Belo Horizonte - Brazil), 19 limbs with primary venous insufficiency and 10 with secondary venous insufficiency entered the study; from these,12 were CEAP 4 and 17 were CEAP 5. Measurements were taken at three moments: without stockings, using them, and 1 hour after removal. Reflux was detected on duplex scanning. Patients with ankle-brachial index < 0.8, and unable to perform the air plethysmography were excluded.

Results: Elastic stockings were more efficient in the control of venous volume, venous filling index, ejection fraction and residual volume fraction in patients with primary chronic venous insufficiency. When patients were wearing stockings, the vascularization flow index had a significant decrease, T0 - 6.03 ml/s to T1 - 4.84 ml/s (P < 0.05). The venous volume decreased from T0 - 137.11 ml to T1 - 104.52 ml (P = 0.004). By comparing moments T0 - 64.55% and T1 - 71.24% (P = 0.0126) we concluded that there was an increase in the ejection fraction while patients were wearing the stockings. The differences found in the residual volume fraction were statistically significant only for patients with primary chronic venous insufficiency.

Conclusion: Medical compression stockings were effective in improving venous hemodynamics of patients with chronic venous insufficiency, mainly in the group with primary chronic venous insufficiency, by reducing the venous reflux, improving the venous volume, the ejection fraction and the residual volume fraction. Beneficial effects were reported only at the moment patients were wearing the stockings.

Key-words: venous insufficiency, pletysmography, bandages.
Palavras-chave: insuficiência venosa, pletismografia, bandagens.

J Vasc Br 2004;3(3):231-7

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Chronic venous insufficiency (CVI) is a condition of long-term venous hypertension caused by valve leakage and/or vein blockage.¹ Symptoms include changes in the skin and subcutaneous tissue, specially in lower extremities.

According to Callam,² CVI affects 2 to 7% of the world population, and leg ulcer is present in 0.5 to 2% of cases. The importance of CVI is not limited to medical aspects, its socio-economic impacts have increased the interest in this ancient and complex disease. Silva³ points out that a 1983 report published by the Brazilian Department of Social Security showed CVI as the 14th cause of temporary work absences.

In order to unify the reporting standards of publications concerning venous diseases, including CVI, the CEAP classification system has been established, in which the letter C corresponds to the clinical findings, E stands for etiology, A refers to anatomic findings, and P to the pathophysiologic component.⁴

CVI treatment may be clinical or surgical, and elastic stockings are considered to be the best option for the clinical treatment of this disease.⁵ With the development of the Jobst compression gradient in 1950, elastic stockings were improved, by delivering maximum pressure at the ankle and gradually decreasing as the stocking extends up the leg. Compression helps blood to flow through the limb, as it is applied along the entire length of the leg. Since then, compression stockings have been widely employed in the clinical treatment of venous insufficiency.⁶

Although further studies on compression therapy are still required to better elucidate how it works, this therapy is highly used in the clinical practice, and it is still difficult to assess its beneficial effects in the treatment of the venous disease.

The objective of the present study is to assess the effects of compression hosiery in patients with severe CVI in lower extremities. By using the parameters of venous hemodynamics, plethysmographic measurements were performed on patients with and without stockings. Records of venous volume (VV), venous filling index (VFI), ejection fraction (EF), and residual volume fraction (RVF) were assessed. The assessment of the compression stockings effect, specially by using a non-invasive method, is considered to be of great importance, as the compression therapy may be the only therapeutic option in cases where venous insufficiency reaches an advanced stage.

PATIENTS AND METHODS

Patients

Sixteen patients (3 male and 13 female; mean age 44.3 years), clinical class 4 and 5, and with primary and secondary venous disease, according to CEAP standards, were included in the study.

Methods

After clinical examination, the patients were classified in classes 4 and 5 of CEAP. They were submitted to duplex ultrasound scanning, as described by van Bemmelen et al.⁷, and their CVI was classified as primary and secondary, according to the venous reflux.

Research protocol

Air-plethysmography (APG) was firstly carried out without stockings (T0). Then, patients went through an adaptation period of 7 to 10 days using the stockings. During this period, they were instructed to put the stockings on in the morning and use them for at least 6 hours. Another APG examination was performed, this time with patients wearing the stockings (T1). After this assessment, stockings were taken off, and 1 hour later (T2) APG was performed again.

Four quantitative variables were analyzed: VV - venous capacity in ml; VFI - rate of veins refilling expressed in ml/s; EF - volume of blood ejected by the calf muscle pump, after one tip-toe motion, and RVF - volume of blood that remains in the limb after 10 additional tip-toes.

All tests were performed in triplicate.⁸ The compression stockings used in the study were knee-length (strong compression Kendall, Sara Lee, Brazil, 30/40 mmHg) with 30% elastane and 70% nylon, and sheer toe. The stockings were analyzed by Instituto Hohenstein,⁹ which issued a technical report on the stockings compression profile. In this assessment, the compression profile is set in points recommended by the European Committee for Standardization,¹⁰ thus it is possible to establish the compression delivered along the full length of the leg.

Patients with ankle-brachial index < 0.8 and those unable to perform PGA were excluded.

Air plethysmography

The APG technique was introduced by Christopoulos et al.¹¹ The air plethysmograph (Model SDV2000, Angiotec, Belo Horizonte, Brazil) is composed of a 35 cm polyurethane cuff with capacity of 5 l. During examination, the cuff is placed around the leg, from knee to ankle.

The test was carried out at a room temperature of about 25 ^oC. Patients were placed in the supine position with the leg elevated and the knee slightly flexed, the foot was propped up on a 20 cm high support to empty veins. The cuff was automatically inflated to a selected pressure of 6 mmHg, providing a good contact with the skin and minimal vein occlusion.

Figure 1 shows the technique used for the APG examination.

Figure 1 - Graphic representation of the APG final result. A: patient in supine position, with the lower limb to be assessed elevated at an angle of 45º; B: the patient is asked to stand, keeping the limb under study at rest; C: the patient performs a dorsiflexion movement of the ankle; D: a series of ten consecutive movements is performed; E: the patient then returns to position B, resting the foot on a support, as in B (according to Christopoulos et al., ¹¹).

Statistics

Twenty-nine lower limbs in sixteen patients with CVI were studied. Data were entered in an Epi Info® 2000 database, and the BIOSTAT® 2.0. software provided means for the statistical assessment. The Kolmogorov-Smirnov goodness-of-fit test was used to ascertain that the data were normally distributed for each variable. The sign test was used to assess VV and VFI variables, and a paired t-test for related samples was applied to the EF and RVF variables. Significance was established at P < 0.05.

The ethical committee of Universidade Federal de Uberlândia approved the study, and all patients signed an informed consent form.

RESULTS

Results of the APG examinations at times T0, T1 and T2 were assessed, considering the group of 29 limbs. In stratification, 12 limbs were C4, and 17 were C5; 19 limbs had primary venous insufficiency; and 10 limbs had secondary venous insufficiency.

Table 1 shows mean values found in the general group with 29 limbs. Records for the VV were 130.60 - T0; 101.65 - T1; and 125.06 - T2. Both the comparison between T0 and T1 and between T1 and T2 were statistically significant (P < 0.05). In the assessment of the VFI of the same group, records were 5.69 ml/s - T0; 4.56 ml/s - T1 and 6.78 ml/s - T2, with P < 0.05 in both moments (T0 - T1 and T1 - T2). In the EF, elastic hosiery was also effective, improving EF while stockings were on, and decreasing when they were taken off . In RVF, P was statistically significant (< 0.05) only between T0 and T1 (31.29 - 25.25%).

Table 1 - Mean values of variables VV, VFI, EF, and RVF obtained through the APG, in patients with CVI (general group of 29 limbs) at moments T0, T1 and T2

Moment	VV	VFI	EF	RFV
T0	130.60	5.69	66.76	31.29
T1	101.6 *	4.56 *	71.96 *	25.25 *
T2	125.06 †	6.78 †‡	66.66 †	28.12

* Statistical significance between T0 and T1.
† Statistical significance between T1 and T2.
‡ Statistical significance between T0 and T2.

In the assessment according to the etiologic classification (Table 2), the use of stockings showed a better result in patients with primary CVI against patients with secondary CVI . In the VV, the use of stockings in patients with primary CVI was effective both at T0-T1 and T1-T2, remaining unaltered in patients with secondary CVI. In the reflux assessment (VFI), stockings improved conditions of patients with primary CVI as compared to those of the group with secondary CVI. The EF at T0-T1 and T1-T2 was statistically significant (P < 0.05) in patients with primary CVI, but in patients with secondary CVI there were not alterations. Eventually, the RVF decreased with the use of stockings in patients with primary CVI and returned to the basal value when stockings were taken off; in the group of patients with secondary CVI there were not alterations with the use of stockings.

Table 2 - Mean values of variables VV, VFI, EF and RVF obtained through the APG, in patients with primary and secondary CVI, at moments T0, T1 and T2

Moment	VV		VFI		EF		RVF
	PRIMARY CVI	SECONDARY CVI	PRIMARY CVI	SECONDARY CVI	PRIMARY CVI	SECONDARY CVI	PRIMARY CVI	SECONDARY CVI
T0	137.11	118.24	6.03	5.06	64.55	70.97	34.16	25.85
T1	104.52*	96.20	4.84*	4.02	71.24*	73.31	27.37 *	21.22
T2	130.66 †	114.41	7.25 †‡	5.88 †	62.93 †‡	73.75	29.90 ‡	24.74

* Statistical significance between T0 and T1.
† Statistical significance between T1 and T2.
‡ Statistical significance between T0 and T2.

Differences were not observed in the assessment of patients in classes C4 and C5 (Table 3). Stockings showed to be statistically effective in the improvement of the VV and the VFI, at T0-T1 and T1-T2, in both groups (P < 0,05). There were not alterations in the RVF and in the EF with the use of stockings.

Table 3 - Mean values of variables VV, VFI, EF and RVF obtained through the APG, in patients class C4 and C5 of CEAP classification, at moments T0, T1 and T2

Moment	VV		VFI		EF		RVF
	C4	C5	C4	C5	C4	C5	C4	C5
T0	118.88	138.88	5.19	6.04	65.32	67.78	29.60	32.48
T1	91.27 *	108.98 *	3.88 *	5.04 *	72.64	71.47	21.30	28.03
T2	108.53	136.73 †	5.57	7.63 †‡	71.59	63.18 †	23.38	31.46

* Statistical significance between T0 and T1.
† Statistical significance between T1 and T2.
‡ Statistical significance between T0 and T2.

In the assessment of the residual effect, comparing the patient at T0 and T2, we found a residual effect in the VFI in the group with primary CVI, class C5, and the general group of 29 limbs.

DISCUSSION

Elastic stockings have been used for over 200 years, and questioning whether they are effective on CVI and/or varicose ulcers treatment is still reported in the literature.⁵ A number of scientific investigations on the effects of compression stockings has already been carried out, but no real conclusion has been reached. Moneta et al.¹² claim that the use of elastic stockings is the best option in the clinical treatment of CVI.

The most common way of assessing elastic stockings effects is through clinical examination, based on what patients report about the development of symptoms and/or edema. Another way of assessing the effect of elastic stockings is based on hemodynamic parameters, specially those of the deep venous system.¹³

The effect of elastic stockings on the venous hemodynamics is controversial, and this may be assigned to the different methodologies used to assess the effects.¹⁴ As for the present study, we have used the AGP, as it is a non-invasive method considered to be the most efficient in the assessment of CVI.¹⁵ Patients in advanced stages of CVI entered the study. Assessment was performed with the APG in different moments: patients wearing the stockings, without the stockings and one hour after removal. Our aim was to assess the effects on the limb during the use of the stockings, and if there would be any residual effect after they had been taken off.

The VV decreases when the compression and size of the stockings are adequately prescribed. Thus, it is suggested that the compression delivered on the superficial varicose veins is mechanical, as it was confirmed by ascending phlebography in patients using elastic hosiery.¹⁶ Another fact that confirms this finding is that when patients with primary CVI were compared against those with secondary CVI, patients with primary CVI had their VV decreased, because only the superficial venous system is damaged. In patients whose deep venous system was severely damaged (classified as secondary CVI), the use of elastic stockings have not altered the VV statistically, thus making evident that the stockings do not act in the deep venous system, in agreement with the literature.¹¹ The findings show that during orthostatism, the VV of limbs of patients with varicose veins was reduced with the use of compression stockings.

It has been documented that the effect of the stockings is completely abolished within a day after their removal,¹⁷ and the literature does not report the effect in the period soon after the stockings are taken off, within 1 and 24 hours. Our assessment observed the VFI in the general group of 29 limbs (see Table 1), in patients class C5 (see Table 3) and with primary CVI (see Table 2). At T0 -T2 there was an increase in the venous reflux after the stockings were removed, this suggests either a reflex deficiency, mediated by sympathetic nerves and vasoactive substances which usually act in the smooth muscle,¹⁸ or lost of vein wall elasticity.¹⁷ Due to these structural changes, the varicose veins lack reflexes. After the stockings are removed, vasodilatation remains the same and venous reflux is increased. This residual effect remains, but a new study to asses VFI within 2 and 24 hours after the stockings removal is required.

During the use of the stockings, the patients of the general group (Table 1), classes C4 and C5 (Table 3), and with primary CVI (Table 2) had their reflux decreased. This suggests that the stockings exerted a mechanical effect on the limb, probably due to reduction of the superficial varicose veins diameter; in many cases, the venous cuspids became closer, decreasing the venous reflux.

The therapy of elastic compression showed better results in the VFI of patients with primary CVI, in agreement with what is reported in the literature.¹¹,^19-21 As the stockings deliver a mechanical pressure on the vein wall, the VV decreases and consequently reflux is reduced.

The EF provides an idea of the venous return, representing volume ejected from the leg during exercise, that is the reason why the calf muscle pump is also called "peripheral heart". The use of stockings potentialize the EF parameter. Other authors report that although there is not a significant change in the EF with the use of stockings, it is improved while they are worn. Data found in the present work are in accordance with the literature: in patients with primary CVI the action of the calf muscle pump was improved during the use of the elastic stockings; and when it was removed, the EF decreased, making evident that the stockings potentialize the effects of the calf muscle pump during use.

During physical activity, as the blood flows upwards, the distal venous pressure is reduced. During standing, pressure delivered by the venous blood is about 100 mmHg and, after calf muscle contraction, during the walking movement, it falls to 30 mmHg. This is the ambulatory venous pressure. The cyclic pressure reduction after muscles contraction during exercise is indirectly assessed by the RVF, which, on its turn is directly related to the invasive ambulatory venous pressure.¹¹ The effect of elastic stockings on the RVF is controversial. Some studies show good results and others could not demonstrate the action of stockings in this hemodynamic parameter.^11,14

In the general group of 29 limbs, we found that the use of stockings improved the RVF parameter of patients with primary CVI, in accordance with other studies^19-21 which employed the same non-invasive method and used different compression stockings.

On the other hand, when we assessed patients with secondary CVI and classes C4 and C5, there was not an improvement in the RVF with the use of stockings. These data agree with Mayberry et al.¹⁴ who, using the same methodology, obtained similar results.

As it has been demonstrated in the study and according to the literature, the use of elastic stockings in the RVF is controversial. Further studies are required, which compare different methods, with different stages of CVI and using different levels of compression, in order to establish what the action of stockings in the RVF parameter is.

The present study showed that the use of elastic stocking was more efficient in patients with primary CVI, with no or small effect in the group of patients with secondary CVI. The same result had already been reported by Guimarães et al.,²² who also assessed the use of elastic stockings (30-40 mmHg) in patients with CVI, with a non-invasive method (photoplethysmography). Thus, we conclude that the APG is a non-invasive method that can be used to assess the venous hemodynamics of lower limbs and that should be employed to monitor the effects of elastic stockings.

Once there are not many surgical options in the treatment of advanced stages of CVI, such as in patients with dermatofibrosis, hyperpigmentation and ulcer scars, the use of elastic stockings appears as a good therapeutic option, improving the hemodynamic patterns, and consequently improving life-quality, although this aspect has not been assessed in the present study.

REFERENCES

1. Maffei FH. Insuficiência venosa crônica: conceito, prevalência, etiopatogenia e fisiopatologia. In: Maffei FH, editor. Doenças Vasculares Periféricas. Rio de Janeiro: Medsi; 2001. p. 1581-90.

2. Callam MJ. Epidemiology of varicose veins. Br J Surg 1994;81:167-73.

3. Silva MJC. Insuficiência venosa crônica: diagnóstico e tratamento clínico. In: Maffei FH, editor. Doenças Vasculares Periféricas. Rio de Janeiro: Medsi; 2002. p. 1591-1602.

4. Porter JM, Moneta GL. An International Consensus Committee on Chronic Venous Disease. Reporting standards in venous disease: an update. J Vasc Surg 1995;21:635-45.

5. Nicoloff AD, Moneta G, Porter JM. Compression treatment of chronic venous insufficiency. In: Glovizki P, Yao JST, editors. Handbook of Venous Disease. New York: Arnold; 2001. p. 303-8.

6. Bergan JJ. Conrad Jobst and the development of pressure gradient therapy for venous disease. In: Bergan JJ, Yao JS, editors. Surgery of the Veins. Orlando: Grune & Stratton; 1985. p. 529-40.

7. van Bemmelen PS, Bedford G, Beach K, Strandness DE. Quantitative segmental evaluation of venous valvular reflux with duplex ultrasound scanning. J Vasc Surg 1989;10:425-31.

8. Yang D, Vandongen YK, Stacey MC. Variability and reliability of air plethysmography measurements for the evaluation of chronic venous disease. J Vasc Surg 1997;26:638-42.

9. Hohenstein Research Institute [site na Internet]. Boennigheim, Alemanha [atualizado em agosto de 2004; citado em 24 de agosto de 2004]. Disponível em: http://www.hohenstein.de/englisch/abt4.htm.

10. European Committee for Standardization. Adapted European Prestandard. Medical compression hosiery. ENV 12718. Brussels, 2001.

11. Christopoulos DG, Nicolaides AN, Szendro G, Irvine AT, Bull ML, Eastcott HH. Air-plethysmography and the effect of elastic compression on hemodynamics of the leg. J Vasc Surg 1987;5:148-59.

12. Moneta LG, Nehler MR, Chitwood RW, Porte JM. The natural history, pathophysiology, and nonoperative treatment of chronic venous insufficiency. In: Rutherford RB. Vascular surgery. Philadelphia: Saunders; 1995. p. 1837-50.

13. Mayberry JC, Moneta GL, DeFrang RD, Porter JM. The influence of elastic compression stockings on deep venous haemodynamics. J Vasc Surg 1991;13:91-100.

14. Nicolaides AN, Cardiovascular Disease Educational and Research Trust, European Society of Vascular Surgery, The International Angiology Scientific Activity Congress Organization, International Union of Angiology, Union Internationale de Phlebologie at the Abbaye des Vaux de Cernay. Investigation of chronic venous insufficiency: a consensus statement (France, March 5-9, 1997). Circulation. 2000;102(20):E126-63.

15. Bays RA, Healy DA, Atnip RG, Neumyer M, Thiele BL. Validation of air plethysmography, photoplethysmography, and duplex ultrasonography in the evaluation of severe venous stasis. J Vasc Surg 1994;20:721-7.

16. Husni, EA, Ximenes JOC, Goyette EM. Elastic support of the lower limbs in hospital patients: a critical study. JAMA 1970;214:1456-62.

17. Labropoulos N, Leon M, Volteas N, Nicolaides AN. Acute and long-term effect of elastic stockings in patients with varicose veins. Int Angiol 1994;13:119-23.

18. Browse NL, Burnand KG, Irvine AT, Wilson NM. Fisiologia e anatomia funcional. In: Browse NL, Burnand KG, Irvine AT, Wilson NM. Doenças venosas: Dilivros; 2001. p. 47-62.

19. Zajkowski PJ, Proctor MC, Wakefield TW, Bloom J, Blessing B, Greenfield LJ. Compression stockings and venous function. Arch Surg 2002;137:1064-8.

20. Ibegbuna V, Delis KT, Nicolaides AN, Aina O. Effect of elastic compression stockings on venous hemodynamics during walking. J Vasc Surg 2003;37:420-5.

21. Christopoulos DG, Nicolaides NA, Belcaro G. The effect of elastic compression on calf muscle pump function. Phlebology 1990;5:13-9.

22. Guimarães PC, Neto BM, Aun R, Fortunato FJ, Langer B. Avaliação da eficácia da compressão elástica nos membros inferiores através da fotopletismografia. Cirurgia Vascular e Angiologia 1993;9(3):7 Supl.