Long-Term Follow up of the Effects of Extracorporeal Shockwave Therapy (ESWT) on Microcirculation in a Denervated Muscle Flap

Focused shockwave therapy in diabetic foot ulcers: secondary endpoints of two multicentre randomised controlled trials

OBJECTIVE

The objective of this paper is to present the secondary safety and efficacy outcomes from two studies of focused extracorporeal shockwave therapy (ESWT) used adjunctively with standard care in the treatment of neuropathic diabetic foot ulcers (DFU) (1A or 2A on the University of Texas grading scheme), compared with sham treatment and standard care.

METHOD

We carried out two multicentre, multinational, randomised, sham-controlled, double-blinded, phase III clinical studies using standard care with adjunctive focused ESWT compared with sham treatment and standard care in patients with a DFU. DFUs that did not reduce in volume by at least 50% over two weeks' standard treatment were included. DFUs were randomised and managed with standard care and focused ESWT (pulsed acoustic cellular expression; dermaPACE System, SANUWAVE Health, Inc.) active therapy, or with standard care and sham treatment, four times over a two-week treatment phase in study 1 and up to eight times over 12 weeks in study 2. Standard care continued in both studies throughout the 12-week treatment phase. Secondary outcomes were indicators of wound closure and progression, pain, infection, amputation and recurrence, and device reliability. Efficacy-related secondary endpoints were measured at 12, 20 and 24 weeks. The studies were analysed separately and following statistical comparison to justify the method, as a pooled data set.

RESULTS

Wound area reduction (48.6% versus 10.7%, p=0.015, intention to treat (ITT) population with last observation carried forward (LOCF)) and perimeter reduction (46.4% versus 25.0%, p=0.022, ITT population with LOCF) were significantly greater in the active therapy group compared with the sham-treated group, respectively. The difference in time to wound closure in the pooled ITT population was significantly in favour of the active therapy group (84 days versus 112 days for 25% of subjects to reach wound closure in the active and sham-treated groups, respectively; p=0.0346). The proportion of subjects who achieved wound area reduction (WAR) from baseline at week 12 of ≥90% was significantly higher in the active therapy group. The incidence and nature of infection were consistent with previously published studies, and pain was not increased in the active therapy group. Amputation was insignificantly higher in the sham-treated group and recurrence did not differ. The ESWT device was found to be reliable.

CONCLUSION

The outcomes for the primary and secondary endpoints from these studies show that ESWT administered adjunctively with standard care is an effective advanced therapy for neuropathic DFUs (grade 1A and 2A) that do not respond to two weeks' standard care alone by reducing wound volume by at least 50%.

The effect of low intensity shockwave treatment (Li-SWT) on human myoblasts and mouse skeletal muscle

Background

Transplanting myogenic cells and scaffolds for tissue engineering in skeletal muscle have shown inconsistent results. One of the limiting factors is neovascularization at the recipient site. Low intensity shockwave therapy (Li-SWT) has been linked to increased tissue regeneration and vascularization, both integral to survival and integration of transplanted cells. This study was conducted to demonstrate the response of myoblasts and skeletal muscle to Li-SWT.

Method

Primary isolated human myoblasts and explants were treated with low intensity shockwaves and subsequently cell viability, proliferation and differentiation were tested. Cardiotoxin induced injury was created in tibialis anterior muscles of 28 mice, and two days later, the lesions were treated with 500 impulses of Li-SWT on one of the legs. The treatment was repeated every third day of the period and ended on day 14 after cardiotoxin injection.. The animals were followed up and documented up to 21 days after cardiotoxin injury.

Results

Li-SWT had no significant effect on cell death, proliferation, differentiation and migration, the explants however showed decreased adhesion. In the animal experiments, qPCR studies revealed a significantly increased expression of apoptotic, angiogenic and myogenic genes; expression of Bax, Bcl2, Casp3, eNOS, Pax7, Myf5 and Met was increased in the early phase of regeneration in the Li-SWT treated hind limbs. Furthermore, a late accumulative angiogenic effect was demonstrated in the Li-SWT treated limbs by a significantly increased expression of Angpt1, eNOS, iNOS, Vegfa, and Pecam1.

Conclusion

Treatment was associated with an early upregulation in expression of selected apoptotic, pro-inflammatory, angiogenic and satellite cell activating genes after muscle injury. It also showed a late incremental effect on expression of pro-angiogenic genes. However, we found no changes in the number of PAX7 positive cells or blood vessel density in Li-SWT treated and control muscle. Furthermore, Li-SWT in the selected doses did not decrease survival, proliferation or differentiation of myoblasts in vitro.

Electronic supplementary material

The online version of this article (10.1186/s12891-017-1879-4) contains supplementary material, which is available to authorized users.

The dose-effect relationship in extracorporeal shock wave therapy: the optimal parameter for extracorporeal shock wave therapy

BACKGROUND

Extracorporeal shock wave therapy (ESWT) has been demonstrated to have the angiogenic effect on ischemic tissue. We hypothesize that ESWT exerts the proangiogenesis effect with an energy density-dependent mode on the target cells.

MATERIALS AND METHODS

Endothelial progenitor cells (EPCs) of rats were obtained by cultivation of bone marrow-derived mononuclear cells. EPCs were divided into five groups of different energy densities, and each group was furthermore subdivided into four groups of different shock numbers. Thus, there were 20 subgroups in total. The expressions of angiogenic factors, apoptotic factors, inflammation mediators, and chemotactic factors were examined, and the proliferation activity was measured after ESWT.

RESULTS

When EPCs were treated with low-energy (0.04-0.13 mJ/mm(2)) shock wave, the expressions of endothelial nitric oxide synthase, angiopoietin (Ang) 1, Ang-2, and B-cell lymphoma 2 increased and those of interleukin 6, fibroblast growth factor 2, C-X-C chemokine receptor type 4, vascular endothelial growth factor a, Bcl-2-associated X protein, and caspase 3 decreased. stromal cell-derived factor 1 changed without statistical significance. When cells were treated with high-energy (0.16 mJ/mm(2)) shock wave, most of the expressions of cytokines declined except the apoptotic factors and fibroblast growth factor 2, and cells lead to apoptosis. The proliferation activity and the ratio of Ang-1/Ang-2 reached their peak values, when cells were treated with ESWT with the intensity ranging from 0.10-0.13 mJ/mm(2) and shock number ranging from 200-300 impulses. Meanwhile, a minimal value of the ratio of Bax/Bcl-2 was observed.

CONCLUSIONS

There is a dose-effect relationship in ESWT. The shock intensity ranging from 0.10-0.13 mJ/mm(2) and shock number ranging from 200-300 impulses were the optimal parameters for ESWT to treat cells in vitro.