Speaking at the Leipzig Interventional Course (LINC; 22–25 January, Leipzig, Germany), Katja Mühlberg of the University of Leipzig, Germany, called for an improvement in the evidence base around the role of compression in healing venous leg ulcers (VLU). Mühlberg outlined the need for more studies to determine the efficacy of different strategies on healing and recurrence, and their impact on patients and budgets.
She argued: “There is an urgent need for education, and for adequately powered high-quality randomised controlled trials comparing different diagnostic and treatment options, with reporting outcomes including time to ulcer healing, ulcer recurrence, adverse events, quality of life, and cost-effectiveness.”
Mühlberg outlined several shortcomings in the current understanding of compression therapy, including the optimum method of compression and its impact on larger ulcers and on long standing ulcers—as well as whether an exercise regimen adjuvant to compression therapy improves outcomes, and the role of debridement. Mühlberg also pointed to a lack of uniformity across countries in how compression strength is classified, likening it to “comparing apples and pears”.
To this point, the EVRA trial published in 2018 compared improvements in ulcer healing between compression therapy plus early intervention (within two weeks) and compression therapy alone plus deferred intervention (after six months). It was concluded that early intervention led to shorter times to ulcer healing, with higher rates of healing and a longer duration of an ulcer-free period.
“But,” Mühlberg asked, “are the effects the same on larger ulcer size and on long-standing ulcers? Larger and long-standing ulcers are negative prognostic markers for healing, and the ulcers which were included in this study were small ones and had a short duration of only three months. We do not know about long-term results because we have only one-year follow up. And, which method is the best choice? We do not know, because all the endovenous methods were permitted in the study. The effect of conventional venous surgery was not studied.”
Although ambulation is known to improve venous healing, Mühlberg queried whether an “exercise regimen adjuvant to compression therapy increases ulcer healing too [compared with compression alone]?” and pointed to a study that analysed the impact of progressive resistance exercise and physical activity: “The meta-analysis could show that the combination of seated heel raising with physical activity had the strongest association with venous leg healing, so we can say the evidence base is growing for incorporation of exercise into venous ulcer treatment.
“We know too, debridement is necessary, effective, and improves ulcer healing. What we do not know is, is there really good evidence, and how do different methods compare? We have surgical ones, mechanical methods, the biosurgical use of maggots, and so on.” However, Mühlberg pointed to a Cochrane review of 10 randomised controlled trials with 715 participants that were unable to perform a meta-analysis, “revealing a very limited evidence base for debridement”.
Research has also failed to determine the most effective method of treatment, as Mühlberg maintained there is no difference in outcomes on ulcer healing and time to healing in studies looking at compression stockings versus bandages, and no reliable data on ulcer recurrence is available. “We have at least moderate-quality evidence that supports compression over non-compression therapy, but without significant difference between the methods. And, until now, we have low-quality evidence that supports the compression effect on ulcer recurrence.”
A prospective randomised five-year follow-up study that compared compression class (CCL) 2 and CCL3 therapy showed a much lower ulcer recurrence for patients treated with CCL3 than CCL2. However, a lack of clear recommendations about the intensity of compression required makes interpretation of any results difficult, and, according to Mühlberg, could be “one reason for the low evidence of compression therapy in most of our trials”.
As compression class definitions vary internationally and across different healthcare systems, comparing research is complicated by the lack of standardisation. More than 50mmHg in the lower leg and 30–40mmHg in the thigh is needed in order to occlude a vein in the standing or sitting position, Mühlberg explained. However, the range between 30 and 50mmHg could be classified in Germany as either CCL 3 or 4, in France as CCL 4, and in Spain as CCL 2 or 3.
A lack of awareness about how to administer compression therapy also contributes to the problem. A German study that evaluated the knowledge and practical skills of healthcare professionals produced “very alarming numbers”, Mühlberg noted, leading to the question, “How many of our patients are correctly treated? We, physicians, have low knowledge about compression therapy, and only 31% of our venous leg ulcer patients receive any compression therapy at all.”
One possible solution, she suggested, “could be telemedicine”, describing a system that is capable of reporting instantaneous changes in bandage pressure, moisture level and local temperature at the wound site. But in the meantime, she advised, information and understanding require further development.