A leg ulcer clinic: audit of the first three years

Resistant Chronic Venous Leg Ulcers: Effect of Adjuvant Systemic Hyperbaric Oxygen Therapy Versus Venous Intervention Alone

The aim of this study was to assess the adjuvant efficacy of adding systemic hyperbaric oxygen therapy (HBOT) to definitive venous intervention for healing of resistant chronic venous leg ulcers (VLUs). From 97 chronic VLUs, 63 were subjected to a pre-study standard wound care. Thirty three ulcers failed to achieve 50% size reduction, after the 4-weeks standard care, and were allocated to be treated with: HBOT plus venous intervention (n = 17), or venous intervention alone (n = 16). Primary outcomes were the change in ulcer area, complete healing frequency and time, as well as ulcer recurrence. There was a history of recurrent ulcer (82.3% vs. 69%) in HBOT versus venous intervention groups, respectively. The comparison between both groups with regard to area change showed non-significant difference after 3 months of therapy, while there was a significant difference at 6 and 12 months. A significant positive correlation was found between the HBO sessions numbers (20-40) and the rate of ulcer size reduction. Ulcer complete closure after 3 months was observed in (41.7%) of HBOT group, versus (23%) in venous intervention group; (p = 0.33). After 12 months, complete closure was observed in (83.3%) of HBOT group, versus (53.8%) in venous intervention group; (p = 0.02). The mean time of complete closure was significantly shorter in HBOT group, (p = 0.001). HBOT may be effective as adjuvant to venous intervention in treatment of chronic resistant VLUs, it should be reserved for persistent ulcer. Randomized controlled trials with larger numbers is still needed to elucidate its exact role and specific indications.

Chronic wounds in Australia: A systematic review of key epidemiological and clinical parameters

Chronic wounds are a significant problem in Australia. The health care-related costs of chronic wounds in Australia are considerable, equivalent to more than AUD $3.5 billion, approximately 2% of national health care expenditure. Chronic wounds can also have a significant negative impact on the health-related quality of life of affected individuals. Studies have demonstrated that evidence-based care for chronic wounds improves clinical outcomes. Decision analytical modelling is important in confirming and applying these findings in the Australian context. Epidemiological and clinical data on chronic wounds are required to populate decision analytical models. Although epidemiological and clinical data on chronic wounds in Australia are available, these data have yet to be systematically summarised. To address these omissions and clarify the state of existing evidence, we conducted a systematic review of the literature on key epidemiological and clinical parameters of chronic wounds in Australia. A total of 90 studies were selected for inclusion. This paper presents a synthesis of the evidence on the prevalence and incidence of chronic wounds in Australia, as well as rates of infection, hospitalisation, amputation, healing, and recurrence.

Upregulation of inducible nitric oxide synthase (iNOS) expression in faster-healing leg ulcers

OBJECTIVE

Chronic leg ulcers represent a growing clinical problem in the light of today's ageing population. Nitric oxide (NO), which is mostly produced by inducible nitric oxide synthase (iNOS) in healing wounds, exerts beneficial effects on many processes of healing, including bactericidal effects, angiogenesis, epithelialisation and ECM formation. This study sought to investigate whether iNOS expression in chronic leg ulcers can be correlated with the healing process.

METHOD

Sixteen patients with chronic leg ulcers were recruited and attempts were made to take punch biopsies at two separate time points (however, a second biopsy could not be obtained on seven patients). A linear healing rate was derived using the obtained ulcer area and perimeter. The iNOS levels in the biopsy samples were assessed using immunoblotting.

RESULTS

The mean linear healing rate of patients with high iNOS levels was significantly higher (p < 0.01) than that of patients with low iNOS levels. An incidental finding was that the linear healing rate was significantly higher (p < 0.05) post-biopsy than before biopsy in the same patients.

CONCLUSION

This study therefore shows for the first time that high iNOS levels are associated with higher healing rates and have the potential to be used in prognostication. This also opens the possibility of augmentation of ulcer healing through the manipulation of wound NO levels.

Abnormal Extracellular Matrix Metabolism in Chronically Ischemic Skin: A Mechanism for Dermal Failure in Leg Ulcers

Extracellular matrix (ECM) metabolism and homeostasis is sensitive to changes in oxygen tension manifest in ischemia. We hypothesize that in chronically ischemic limbs, abnormalities in uninjured skin, secondary to hypoxia, predispose to dermal breakdown. Paired biopsies of uninjured distal ischemic and proximal non-ischemic skin were harvested at below knee amputation from 14 patients with peripheral vascular disease following quantification of ischemia. Age- and site-matched controls were taken at total knee replacement (TKR) and varicose vein (VV) operations. Matrix metalloproteinase (MMP)-2 and -9 expression was determined using gelatin zymography, MMP-1 by western blotting and ELISA and tissue inhibitor of MMP (TIMP) by reverse zymography. Collagen content was measured by determining hydroxyproline levels, and collagen type I synthesis by ELISA. Collagen type I synthesis was upregulated in ischemic tissue compared with non-ischemic matched pairs (p<0.001) and both TKR and VV controls, however, there was no increase in collagen deposition. Levels of MMP-2 (p<0.0005) and TIMP-2 (p<0.01), were elevated in ischemic samples. MMP-9 was unaltered, signifying no inflammatory changes. Tissue ischemia was linked to elevated ECM turnover, associated with matrix failure when compounded with problems of matrix stabilization, likely in ischemia. This represents a potential mechanism for ulcer formation.