Br. J. Surg. 1987, Vol. 74, July, 626-627

C. M. Backhouse, S. D. Blair, A. P. Savage, Jackie Walton and C. N. McCollum

Department of Surgery, Charing Cross and Westminster Medical School, London, UK Correspondence to: Mr C. N. McCollum, Department of Surgery, Charing Cross and Westminster Medical School, St. Dunstan's Road, London W6 8RP, UK

Controlled trial of occlusive dressings in healing chronic venous ulcers

Fifty-six patients with chronic venous ulcers present for a mean of 2.4 years were randomized to either a new occlusive hydrocolloid dressing (GranuJex, Squibb Surgicare) or a porous non-adherent dressing ( N A , Johnson and Johnson). I n all patients, dressings were applied beneath a standard graduated compression bandage. There was no difference between the two groups, with complete healing in 21 out of 28 (75 per cent) of occlusive dressing patients and 22 out of 28 (78 per cent) with N A dressings by 12 weeks. Careful graduated compression bandaging achieves healing even in the majority of so-called resistant chronic venous ulcers; there was no additional benejit JFom applying occlusive dressings which tend to be expensive. Keywords: Venous ulcer, occlusive dressing, graduated compression

Venous ulcers are common and cause considerable morbidity in the adult population of this country'. As healing may be slow or never achieved ulcers create persistent and substantial demands on resources. A wide variety of treatments has been used but it is generally agreed that elevation of the legs and compression bandaging are of central importance. More rapid healing in large ulcers can be achieved, even as an outpatient, by some form of skin grafting' - 4 . This is, however, inappropriate for smaller ulcers which may usually be encouraged to heal within 2-3 months without surgical intervention5. Experimentally, occlusive dressings provide better conditions for rapid epithelialization of granulating wounds than exposure to air, and a new hydrocolloid dressing (Granuflex, Squibb Surgicare) performed particularly well6.'. In this study we compared Granuflex with a commonly used non-occlusive dressing (N A, Johnson and Johnson) beneath standardized graduated compression bandages. Both N A dressings and Granuflex may be left undisturbed for periods of 7 days or longer, allowing their use on outpatients with the minimum demand on nursing services and little disruption of the growing epithelium. This both simplifies and reduces the cost of venous ulcer management.

Materials and methods Fifty-six patients referred to a venous ulcer clinic were randomized to receive either the occlusive hydrocolloid dressing (Granuflex) or a non- adherent non-occlusive dressing (N A). All ulcers in consenting patients were consecutively included except those more than 10cm2 in area which we have previously shown to be better treated by grafting4. A full history and examination were performed with Doppler assessment of arterial pressure at the ankles to confirm that the ulcers were gravitational or venous. Swabs for bacterial culture were regularly taken but antibacterial therapy was used only for spreading cellulitis.

Dressing technique After washing with saline and removal of all loose slough, the allocated dressing was laid on the ulcer and then covered with an absorbant layer of Velband (Johnson and Johnson) which also served to distribute pressure from the bandages.

Bandage technique A standard below-knee graduated compression bandage was applied over the dressing in all patients. A layer of crepe bandage was used to compress the Velband, followed by a layer of Elset bandage (Seton Products Limited) and a final layer of Coban cohesive bandage (3M Health Care Limited). The pressure under this bandage was measured at four points between the medial malleolus and the knee using a Medical

Stocking Tester (Saltzman Limited, Switzerland) in 16 healthy volunteers and achieved a mean (fs.e.m.) at the medial malleolus of 41,8+_ 1.4mmHg with a gradual fall to 16.9 f 1.8mmHg just below the knee. When measured over a 24 h period the pressure on the ankle rose by 5 mmHg during the day, presumably due to foot swelling, and returned to the initial pressure by the following morning.

Follow-up and measurement of ulcer size All patients were recommended to walk whenever possible and to elevate their legs when at rest. The ulcers were inspected at weekly intervals unless infection or excessive exudate necessitated more frequent attention. The size of the ulcer was measured by tracing the margin onto cellophane, then transferring the outline to a card of known area to weight ratio. The excised tracing on the card was weighed and the area calculated.

Results On randomization 28 patients were allocated to each group, which were well-matched for age, sex, duration of ulceration, and previous history of venous disease (Table I). Furthermore, ulcer healing investigation by Doppler, PPG and direct foot vein pressure measurements has shown an equal distribution of superficial and deep venous incompetence between the treatment groups.

The mean size of the ulcers on presentation was 3.4+ 0.4 cm2 for Granuflex, and 3.1 k0.4 cm2 for N A. The healing rate was calculated as the percentage of the original area healed each week and was minimal over the first 2 weeks as the ulcer desloughed at 2.9 per cent for Granuflex and 2.1 per cent for N A. Over the next 4 weeks healing was rapid at 11.4 per cent for Granuflex, and 15.6 for N A, but this slowed as the ulcer size

Table 1 Comparability of treatment groups

Granuflex N A (n = 28) (n = 28)

Mean age (years) Age range (years) Time since first ulcer (years) Median duration of present ulcer (months) Males Females Previous DVT Previous surgery for varicose veins

69.9 3 4 9 2 12.9 22 11 17 7

11

67.5 3@90 13.4 21 12 16 7 5

DVT, deep vein thrombosis

626 N7-1323/87/070626-02$3.GIl 0 1987 Butterworth & Co (Publishers) Ltd

Chronic venous ulcer dressings: C. M. Backhouse et al.

100 r decreased in the final 6 weeks to Granuflex 3.7 per cent and N A 2.8 per cent (Figure 1). There was no difference in mean area or healing rate between the two groups at any time throughout the study period.

Fifteen in each group (54 per cent) had healed by 6 weeks. By 12 weeks, 21 (75percent) of the Granuflex group, and 22 (78 per cent) of the N A group had healed completely (Figure 2). Again, there was no important difference between the groups. The dressing type did not significantly influence bacterial contamination which had no effect on healing unless cellulitis developed. Streptococcal cellulitis was seen in seven cases (four with Granuflex and three with NA) of which three (two Granuflex and one NA) failed to heal by 12 weeks.

Discussion Complete healing was achieved with both types of dressing in more than 75 per cent of venous ulcers suggesting that factors other than the dressings are important in encouraging ulcers to heal. Although most would agree that graduated compression is essential in mobile patients, the ideal pressure and a form of bandaging capable of maintaining it have yet to be determined in clinical studies. Based on a combination of Starling's equation and the known range of venous pressures measured at the ankle in normal, varicose and post-thrombotic legs, an external pressure of 35-40 mmHg at the ankle is theoretically required to prevent capillary transudation in legs with severe venous disease'. The graduated compression bandaging used in this study exerted a mean of 41.8+ 1.4mmHg at the ankle healed 75 per cent of ulcers within 12 weeks.

The moist environment provided by occlusive dressings has been shown experimentally to promote more rapid epithelialization of granulating wounds6,'. Clinically, hydrocolloid dressing was reported to be effective at encouraging healing of pressure sores in an uncontrolled trial and in a study of 35 chronic venous ulcers produced 43 per cent complete healing in 12 weeks'.'. However, results are conflicting with one study comparing Granuflex and zinc oxide paste, showing no advantage for occlusive dressings, while in a similar study the mean ulcer size had reduced by 67 per cent in the Granuflex group compared with 22 per cent in the zinc oxide group".' '. As these results are no better than those achieved by both dressing materials in our study, the evidence of clinical advantage from the use of occlusive dressing for venous ulcers must be questioned.

$ 25

6 15 2

10 L I

0 5 L 0 I 2 3 4 5 6 7 8 9 10 II 12 13

Time (weeks)

Mean area of ulcers in the two treatment groups plotted over Figure 1 the 12-week study period: ---- Granuflex, ~ N A

I

Time (weeks)

Percentage of original 56 ulcers healed each week comparing Figure 2 Granuflex (- - - -) and N A (-)

Granuflex is simple and convenient to use but has a relatively high unit cost, and when applied beneath a four-layer compression bandage produces no faster healing than N A dressings. We have, therefore, failed to show any significant benefit from the use of occlusive dressings in the outpatient management of venous ulcers.

Acknowledgements We are grateful to the following companies who fund our venous research: Johnson and Johnson Limited, 3M Health Care, Sigvaris (Camp Limited), Zyma UK Limited and Squibb Surgicare, who generously supported this project. Jill Wallace prepared this manuscript to her usual high standard.

References 1 .

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Ryan TJ, Given HF, Murphy JJ, Hope-Ross M, Byrnes G. The use of a new occlusive dressing in the management ofvenous stasis ulceration. In: Ryan TJ, ed. An Environment for Healing: The Role ofOcclusion. London: Royal Society of Medicine, 1985: 99- 103. Eriksson G. Comparative study of hydrocolloid dressing and double layer bandage in treatment ofvenous stasis ulceration. In: Ryan TJ, ed. An Environment for Healing: The Role of Occlusion. London: Royal Society of Medicine, 1985: 111-13. Groenewald JH. Comparative effects of HCD and conventional treatment on the healing of venous stasis ulcers. In: Ryan TJ, ed. An Environment for Healing: The Role of Occlusion. London: Royal Society of Medicine, 1985: 105-9.

1984; 11: 102-5.

Paper accepted 9 January 1987

Br. J. Surg., Vol. 74, No. 7, July 1987 627