Risk factors for non-healing ulcers with compression treatmentDragan J. Milic, MD, PhD
Clinic for Vascular Surgery, Clinical Center Nis, Bulevar Zorana Djindjica 48, 18 000 Nis, Serbia
Correspondence:
Dr Dragan J. Milic,
Bulevar Nemanjica 72A/25, 18 000 Nis, Serbia
Tel. (+381 18) 204 004
Fax: (+381 18) 531 950
E-mail:
drmilic@beotel.netVenous leg ulcers (VLUs) have a huge social and economic impact, with the annual health care costs estimated at £300 million in the UK, €250 million in Germany, and $1 billion in the US. The overall incidence of VLUs in patients older than 45 years is 3.5 per 1000 per year and an estimated 1.5% of European adults will have a VLU at some point in their lives.1
Compression therapy remains the most widely used treatment for VLUs and has been utilized in different forms for more than 400 years. Although the mechanism of action of compression therapy is not completely understood it has been suggested that the application of external pressure to the calf muscle raises the interstitial pressure resulting in improved venous return and reduction in the venous hypertension. The goals of compression therapy in the treatment of VLUs are ulcer healing, reduction of pain and edema, and prevention of recurrence. Published healing rates for VLUs obtained with compression therapy range from 40% to 95%. Unfortunately, a significant number of VLUs remain refractory to compression treatment. A possible way to predict nonhealing VLUs is to examine prognostic risk factors that are consistently found in a number of published studies.
Margolis et al2 found that venous stripping and the presence of fibrin on more than 50% of the wound surface were the factors associated with the failure of a VLU to heal. Venous ulcers showing a tendency not to heal in many published studies were those with deep presentation (>2 cm in depth) and ulcers with history of surgical debridement.3 The reason for this is probably complete destruction of skin structures and lack of growth factors in the dermis, which makes the healing process more difficult. On the other hand, the emergence of new skin islets on the wound surface after the beginning of compression treatment is favorable for ulcer healing.
In obese patients more time is needed for ulcer healing and high BMI (> 30 kg/m2) is an indicator of slow healing. Physical inactivity and short walking distance during the day are also indicators of slow healing. The main reason for this is immobility of these patients and inactivity of their muscle pump.3 It may be prudent to introduce intermittent pneumatic compression in the treatment of these patients in order to stimulate the muscle pump and to improve ulcer healing.
Independent parameters associated with nonhealing of VLUs when treated with compression therapy in most studies are large ulcer surface, ulcer of long duration,4 fixed ankle joint with reduced ankle range of motion (ROM)5 and calf:ankle circumference (CAC) ratio <1.3.3
Fixed ankle joint and reduced ankle ROM were significantly correlated with ejection fraction and residual volume fraction measured by air plethysmography, which indicates the importance of calf pump function in the development of venous ulceration. One of the main contributors to decreased ankle ROM in patients with VLUs is probably inactivity. Bed rest and prolonged inactivity may lead to muscle atrophy, contracture, and degenerative joint disease. Pain with ankle motion could also cause a decrease in voluntary ankle flexion and extension.5
A CAC ratio <1.3 was also an indicator of nonhealing venous ulcers. Low CAC ratio is an indicator of diminished calf muscle pump efficacy and if low CAC ratio develops during the compression treatment it could mean that excessive pressure has been implemented for too long, leading to calf muscle atrophy. In these cases a compression system with lower interface pressure should be used.
Taking into account published studies, all monitored parameters for ulcer healing when treated with compression therapy can be classified into 4 groups:
1. Factors with no influence on ulcer healing (gender, previous operations),
2. Factors indicative of a favorable prognosis for ulcer healing (ulceration surface < 5 cm2, short ulcer duration < 12 months, emergence of new skin islets on wound surface after the beginning of compression treatment, younger age).
3. Indicators of slow healing (high BMI, short walking distance during the day, history of surgical wound debridement, >50% of wound covered with fibrin, depth of the wound > 2 cm), and
4. Risk factors associated with nonhealing (ulceration surface > 20 cm2, ulcers of long duration, fixed ankle joint and reduced ROM, CAC ratio <1.3.
References:
1. Baker SR, Stacey MC, Jopp-McKay AG, Hoskin SE, Thompson PJ. Epidemiology of chronic venous ulcers. Br J Surg. 1991;78:864-867.
2. Margolis DJ, Berlin JA, Strom BL. Risk factors associated with the failure of a venous leg ulcer to heal. Arch Dermatol. 1999;135:920-926.
3. Milic DJ, Zivic SS, Bogdanovic DC, Karanovic ND, Golubovic ZV. Risk factors related to the failure of venous leg ulcers to heal with compression treatment. J Vasc Surg. 2009;49:1242-1247.
4. Margolis DJ, Berlin JA, Strom BL. Which venous leg ulcers will heal with limb compression bandages? Am J Med. 2000;109:15-19.
5. Back TL, Padberg FT, Araki CT, Thompson PN, Hobson RW. Limited range of motion is a significant factor in venous ulceration. J Vasc Surg. 1995;22:519-523.