Application of various power densities of ultrasound in the treatment of leg ulcers

Therapeutic ultrasound for venous leg ulcers

BACKGROUND

Venous leg ulcers are a type of chronic, recurring, complex wound that is more common in people aged over 65 years. Venous ulcers pose a significant burden to patients and healthcare systems. While compression therapy (such as bandages or stockings) is an effective first-line treatment, ultrasound may have a role to play in healing venous ulcers.

OBJECTIVES

To determine whether venous leg ulcers treated with ultrasound heal more quickly than those not treated with ultrasound.

SEARCH METHODS

We searched the Cochrane Wounds Specialised Register (searched 19 September 2016); the Cochrane Central Register of Controlled Trials (CENTRAL; the Cochrane Library 2016, Issue 8); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations, MEDLINE Daily and Epub Ahead of Print) (1946 to 19 September 2016); Ovid Embase (1974 to 19 September 2016); and EBSCO CINAHL Plus (1937 to 19 September 2016). We also searched three clinical trials registries and the references of included studies and relevant systematic reviews. There were no restrictions based on language, date of publication or study setting.

SELECTION CRITERIA

Randomised controlled trials (RCTs) that compared ultrasound with no ultrasound. Eligible non-ultrasound comparator treatments included usual care, sham ultrasound and alternative leg ulcer treatments.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the search results and selected eligible studies. Details from included studies were summarised using a data extraction sheet, and double-checked. We attempted to contact trial authors for missing data.

MAIN RESULTS

Eleven trials are included in this update; 10 of these we judged to be at an unclear or high risk of bias. The trials were clinically heterogeneous with differences in duration of follow-up, and ultrasound regimens. Nine trials evaluated high frequency ultrasound; seven studies provided data for ulcers healed and two provided data on change in ulcer size only. Two trials evaluated low frequency ultrasound and both reported ulcers healed data.It is uncertain whether high frequency ultrasound affects the proportion of ulcers healed compared with no ultrasound at any of the time points evaluated: at seven to eight weeks (RR 1.21, 95% CI 0.86 to 1.71; 6 trials, 678 participants; low quality evidence - downgraded once for risk of bias and once for imprecision); at 12 weeks (RR 1.26, 95% CI 0.92 to 1.73; 3 trials, 489 participants; moderate quality evidence - downgraded once for imprecision); and at 12 months (RR 0.93, 95% CI 0.73 to 1.18; 1 trial, 337 participants; low quality evidence - downgraded once for unclear risk of bias and once for imprecision).One trial (92 participants) reported that a greater percentage reduction in ulcer area was achieved at four weeks with high-frequency ultrasound, while another (73 participants) reported no clear difference in change in ulcer size at seven weeks. We downgraded the level of this evidence to very low, mainly for risk of bias (typically lack of blinded outcome assessment and attrition) and imprecision.Data from one trial (337 participants) suggest that high frequency ultrasound may increase the risk of non-serious adverse events (RR 1.29, 95% CI 1.02 to 1.64; moderate quality evidence - downgraded once for imprecision) and serious adverse events (RR 1.21, 95% CI 0.78 to 1.89; moderate quality evidence downgraded once for imprecision).It is uncertain whether low frequency ultrasound affects venous ulcer healing at eight and 12 weeks (RR 3.91, 95% CI 0.47 to 32.85; 2 trials, 61 participants; very low quality evidence (downgraded for risk of bias and imprecision)).High-frequency ultrasound probably makes little or no difference to quality of life (moderate quality evidence, downgraded for imprecision). The outcomes of adverse effects, quality of life and cost were not reported for low-frequency ultrasound treatment.

AUTHORS' CONCLUSIONS

It is uncertain whether therapeutic ultrasound (either high or low frequency) improves the healing of venous leg ulcers. We rated most of the evidence as low or very low quality due to risk of bias and imprecision.

Clinical and immunohistopathological aspects of venous ulcers treatment by Low-Intensity Pulsed Ultrasound (LIPUS)

The immunological mechanisms that are triggered by Low-Intensity Pulsed Ultrasound (LIPUS) in wound healing are unknown. In the present study, experimental groups were used to assess the treatment of chronic venous ulcers with 30mW/cm(2) SATA peripheral LIPUS three times per week compared to a daily treatment of 1% silver sulfadiazine (SDZ). The ulcers of the SDZ group (n=7) (G1) and LIPUS group (n=9) (G2) were photographed five times three months, and the images were analyzed using ImageJ software to quantify the total area (S), fibrin/sphacel area (yellow) and granulation area (red). The healing process was evaluated by the wound healing rate (WHR), granulation tissue rate (GTR) and fibrin/sphacel tissue rate (FTR). The ulcers were biopsied on days 1 and 45 and stained for collagen fiber quantification (picrosirius) and CD68(+) protein and VEGF (vascular endothelial growth factor) expression using HRP-streptavidin (horseradish peroxidase-streptavidin). On day 90, G2 had a mean 41% decrease in the ulcer area, while no decrease was observed in G1 (p<0.05). An increased tendency toward positive labeling of collagen fibers and VEGF (p>0.05) was observed in G2 compared to G1, and the number of CD68(+) cells was greater in G2 than in G1 (p<0.05). LIPUS presents superior activity compared to SDZ in stimulating the inflammatory and proliferative (angiogenesis and collagenesis, respectively) phases of chronic venous wound healing.

Therapeutic ultrasound for venous leg ulcers

BACKGROUND

Venous leg ulcers pose a significant burden for patients and healthcare systems. Ultrasound (US) may be a useful treatment for these ulcers.

OBJECTIVES

To determine whether US increases the healing of venous leg ulcers.

SEARCH STRATEGY

We searched the Cochrane Wounds Group Specialised Register (searched 24 February 2010); The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 1, 2010); Ovid MEDLINE (1950 to February Week 2 2010); In-Process & Other Non-Indexed Citations (searched 24 February 2010); Ovid EMBASE 1980 to 2010 Week 07; EBSCO CINAHL 1982 to 24 February 2010.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing US with no US.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the search results and selected eligible studies. Details from included studies were summarised using a data extraction sheet, and double-checked. We tried to contact trial authors for missing data.

MAIN RESULTS

Eight trials were included; all had unclear, or high, risks of bias, with differences in duration of follow-up, and US regimens. Six trials evaluated high frequency US and five of these reported healing at 7 - 8 weeks. Significantly more patients healed with US than without it at 7 - 8 weeks (pooled RR 1.4, 95% CI 1.0 to 1.96), but later assessments at 12 weeks showed the increased risk of healing with US was no longer statistically significant (pooled RR 1.47, 95% CI 0.99 to 2.20). One poor-quality study of high-frequency US found no evidence of an effect on healing after three weeks' treatment.Two trials evaluated low frequency US and reported healing at different time points. Both trials reported no evidence of a difference in the proportion of ulcers healed with US compared with no US: both were significantly underpowered.

AUTHORS' CONCLUSIONS

The trials evaluating US for venous leg ulcers are small, poor-quality and heterogeneous. There is no reliable evidence that US hastens healing of venous ulcers. There is a small amount of weak evidence of increased healing with US, but this requires confirmation in larger, high-quality RCTs. There is no evidence of a benefit associated with low frequency US.

The use of therapeutic ultrasound in venous leg ulcers: a randomized, controlled clinical trial

Objectives

To estimate the usefulness of therapeutic ultrasound for healing of venous leg ulcers.

Methods

Eighty-one patients were included in this study. Patients in groups 1 and 2 were treated surgically. Patients in groups 3 and 4 were treated conservatively. Patients in groups 1 and 3 were additionally treated with the ultrasound (1 MHz, 0.5 W/cm2) once daily, six times a week for seven weeks.

Results

Comparison of the number of complete healed wounds indicated statistically significant differences between groups 1 and 4 ( P = 0.03), 2 and 4 ( P = 0.03), 3 and 4 ( P = 0.03) in favour of groups 1, 2 and 3. Comparison of the other parameters also demonstrated more efficient therapy effects in groups 1, 2 and 3 than in group 4. There were no statistical differences in all examined parameters between groups 1, 2 and 3 ( P > 0.05).

Conclusions

The ultrasound is an efficient and useful method only in conservatively treated venous leg ulcers. There are no special reasons for application of the ultrasound in surgically treated patients. A well-conducted surgical operation is much more effective for a healing process than conservative pharmacological procedures.

Therapeutic ultrasound for venous leg ulcers

BACKGROUND

Venous leg ulceration is a common problem, representing a significant burden on the patient and the healthcare system. They are caused by venous insufficiency and tend to be chronic and recurring. Management usually includes use of wound dressings plus compression stockings or bandages. It has been suggested that therapeutic ultrasound may have an adjuvant effect and promote healing however its effects are unclear.

OBJECTIVES

To determine whether therapeutic ultrasound increases the healing of venous leg ulcers.

SEARCH STRATEGY

We searched the Cochrane Wounds Group Specialised Register (August 2007), The Cochrane Central Register of Controlled Trials (CENTRAL) - The Cochrane Library Issue 3, 2007, Ovid MEDLINE - 1950 to July Week 4 2007, Ovid EMBASE - 1980 to 2007 Week 31, Ovid CINAHL - 1982 to August Week 1 2007.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing therapeutic ultrasound with placebo (sham) ultrasound, or other (standard) treatment.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the results of the searches for eligible RCTs and obtained full reports. A third author assessed the results of the update searches for eligible RCTs. Details from the eligible studies were extracted and summarised by a review author using a data extraction sheet. Attempts were made to contact trial authors to obtain missing data or for clarification.

MAIN RESULTS

A total of eight eligible trials were identified and were all of either medium or high risk of bias. Five trials compared ultrasound therapy with placebo (sham) ultrasound, three trials compared ultrasound therapy with standard treatment. Trials varied in terms of ulcer size, regimen and duration of follow up. No trials individually found a statistically significant difference in the number of ulcers healed between any of the therapies, however on pooling trials (different durations of follow up) for the outcome of risk healing, significantly more ulcers were completely healed with ultrasound (RR 1.49, 95% CI 1.07 to 2.09). Some trials also found that ultrasound increases the rate of change of wound size and/or reduces the size of existing ulcers, whilst other trials did not find this effect to be significant. When all trials reporting percentage ulcer area remaining were pooled there was a significant benefit associated with ultrasound (WMD -5.34%, 95% CI -8.38 to -2.30).

AUTHORS' CONCLUSIONS

The available evidence suggests that ultrasound may increase healing of venous leg ulcers. These conclusions are based on the results of only eight small studies of generally poor quality and therefore should be interpreted with caution.