The dynamic response of human lungs due to underwater shock wave exposure

Since the 19th century, underwater explosions have posed a significant threat to service members. While there have been attempts to establish injury criteria for the most vulnerable organs, namely the lungs, existing criteria are highly variable due to insufficient human data and the corresponding inability to understand the underlying injury mechanisms. This study presents an experimental characterization of isolated human lung dynamics during simulated exposure to underwater shock waves. We found that the large acoustic impedance at the surface of the lung severely attenuated transmission of the shock wave into the lungs. However, the shock wave initiated large bulk pressure-volume cycles that are distinct from the response of the solid organs under similar loading. These pressure-volume cycles are due to compression of the contained gas, which we modeled with the Rayleigh-Plesset equation. The extent of these lung dynamics was dependent on physical confinement, which in real underwater blast conditions is influenced by factors such as rib cage properties and donned equipment. Findings demonstrate a potential causal mechanism for implosion injuries, which has significant implications for the understanding of primary blast lung injury due to underwater blast exposures.

Efficacy and safety of cardiac shock wave therapy for patients with severe coronary artery disease: A randomized, double-blind control study

BACKGROUND

Previous studies proved the efficacy of cardiac shock wave therapy (CSWT) for coronary artery disease (CAD) patients who are not candidate for reperfusion therapy. Randomized control trials are limited. We try to explore the efficacy and safety of CSWT for patients with severe CAD.

METHODS

Thirty patients with severe CAD who had obvious ischemia on myocardial perfusion imaging (MPI) were enrolled and randomly assigned to the CSWT group or the control group. They had received optimal medication treatment for at least three months. Nine sessions of shock wave therapy were conducted over 3 months. CSWT group received the real treatment, while the control group received the pseudo-treatment. Clinical symptom, imaging outcomes and safety parameters were compared between two groups.

RESULTS

After treatment, regional stress score (P = .023), improvement rate (IR) of ischemic area (IA) stress (P < .001) and IR of IA difference (P < .001) were significantly favor CSWT group. The interaction of summed rest score (P < .001), summed stress score (P = .004), summed difference score (P = .036) were significantly improved in the CSWT group compared to the control group. Seattle angina questionnaire, quality of life (QOL) and the distance of six-minute walking test (6MWT) were improved in both groups without significant difference between them. Hemodynamic parameters were stable during procedure. Myocardial injury markers showed no changes in two groups.

CONCLUSIONS

Our study demonstrated CSWT could effectively and safely improve myocardial perfusion in patients with severe CAD. Clinical symptom, QOL and 6MWT were all improved after treatment, but no significant difference between two groups.

The utilization of small non-mammals in traumatic brain injury research: A systematic review

Traumatic brain injury (TBI) is the leading cause of death and disability worldwide and has complicated underlying pathophysiology. Numerous TBI animal models have been developed over the past decade to effectively mimic the human TBI pathophysiology. These models are of mostly mammalian origin including rodents and non-human primates. However, the mammalian models demanded higher costs and have lower throughput often limiting the progress in TBI research. Thus, this systematic review aims to discuss the potential benefits of non-mammalian TBI models in terms of their face validity in resembling human TBI. Three databases were searched as follows: PubMed, Scopus, and Embase, for original articles relating to non-mammalian TBI models, published between January 2010 and December 2019. A total of 29 articles were selected based on PRISMA model for critical appraisal. Zebrafish, both larvae and adult, was found to be the most utilized non-mammalian TBI model in the current literature, followed by the fruit fly and roundworm. In conclusion, non-mammalian TBI models have advantages over mammalian models especially for rapid, cost-effective, and reproducible screening of effective treatment strategies and provide an opportunity to expedite the advancement of TBI research.

A novel mouse model of mild traumatic brain injury using laser-induced shock waves

Blast-induced mild traumatic brain injury (mild bTBI) has been a frequent battlefield injury in soldiers during the conflicts in Iraq and Afghanistan. Understanding the pathophysiology and determining effective treatments for mild bTBI has become an international problem in the field of neurotrauma research. Contributing to this problem is a lack of an experimental model that accurately mimics the characteristics of mild bTBI. To date, the "mild'' versions of common experimental models of TBI have simply been less severe degrees of traumatic injury; these animals do not necessarily exhibit the clinical characteristics of mild bTBI seen in humans. Therefore, our first objective was to develop a highly controlled mouse model of bTBI using laser-induced shockwaves (LISWs). We established the parameters necessary to cause a reproducible injury of very mild severity, the most important feature seen in clinical practice. We defined very mild bTBI as having no traumatic change on the head visible to the naked eye after the insult was applied using very mild shockwaves to the heads of mice. Our very mild bTBI mouse model exhibited neurobehavioral changes in the chronic phase, such as cognitive impairment and depression-like behavior. We also observed an increase in 5-bromo-2'-deoxyuridine-positive, proliferating cells in the dentate gyrus during the acute phase and a subsequent decrease during the chronic phase. This model appears to be an accurate representation of the damage occurring in actual mild bTBI patients. We also found that an increase in cell proliferation in the dentate gyrus during the acute phase is the most prominent feature after a TBI.

Survival of Extremotolerant Bacteria from the Mukundpura Meteorite Impact Crater

Carbonaceous meteorites provide clues with regard to prebiotic chemistry and the origin of life. Geological Survey of India recorded a carbonaceous chondrite meteorite fall in Mukundpura, India, on June 6, 2017. We conducted a study to investigate the microbial community that survived the meteorite impact. 16S rRNA metagenomic sequencing indicates the presence of Actinobacteria, Proteobacteria, and Acidobacteria in meteorite impact soil. Comparative phylogenetic analysis revealed an intriguing abundance of class Bacilli in the impact soil. Bacillus thermocopriae IR-1, a moderately thermotolerant organism, was isolated from a rock, impacted by the Mukundpura meteorite. We investigated the resilience of B. thermocopriae IR-1 to environmental stresses and impact shock in a Reddy shock tube. Bacillus thermocopriae IR-1 survived (28.82% survival) the effect of shock waves at a peak shock pressure of 300 kPa, temperature 400 K, and Mach number of 1.47. This investigation presents the first report on the effect of impact shock on B. thermocopriae IR-1. The study is also the first report on studying the microbial diversity and isolation of bacteria from impact crater soil immediately after meteorite impact event.

Effective testing of personal protective equipment in blast loading conditions in shock tube: Comparison of three different testing locations

We exposed a headform instrumented with 10 pressure sensors mounted flush with the surface to a shock wave with three nominal intensities: 70, 140 and 210 kPa. The headform was mounted on a Hybrid III neck, in a rigid configuration to eliminate motion and associated pressure variations. We evaluated the effect of the test location by placing the headform inside, at the end and outside of the shock tube. The shock wave intensity gradually decreases the further it travels in the shock tube and the end effect degrades shock wave characteristics, which makes comparison of the results obtained at three locations a difficult task. To resolve these issues, we developed a simple strategy of data reduction: the respective pressure parameters recorded by headform sensors were divided by their equivalents associated with the incident shock wave. As a result, we obtained a comprehensive set of non-dimensional parameters. These non-dimensional parameters (or amplification factors) allow for direct comparison of pressure waveform characteristic parameters generated by a range of incident shock waves differing in intensity and for the headform located in different locations. Using this approach, we found a correlation function which allows prediction of the peak pressure on the headform that depends only on the peak pressure of the incident shock wave (for specific sensor location on the headform), and itis independent on the headform location. We also found a similar relationship for the rise time. However, for the duration and impulse, comparable correlation functions do not exist. These findings using a headform with simplified geometry are baseline values and address a need for the development of standardized parameters for the evaluation of personal protective equipment (PPE) under shock wave loading.

Tracking kidney stones in a homogeneous medium using a trilateration approach

Shock wave lithotripsy is a non-invasive procedure by which kidney stones are fragmented by thousands of shock waves. Currently, many shock waves are delivered to the body that do not impact the stone, but do result in tissue trauma. This motivates developing a monitoring system to locate kidney stones, with the goal of gating shock waves not aligned with the stone, and hence, reducing renal trauma during lithotripsy. The system consists of a circular array housing twenty-two 0.5 MHz transducers that can be mounted on a clinical lithotripter. It was deployed in a water tank and tested with two stone models made from gypsum cement and a stone model fragment. An algorithm consisting of threshold detection, automatic rejection of weak signals, and triangulation was developed to determine the location of stones. The results show that within ±15 mm of the focus of the lithotripter, the accuracy was better than 4 mm in the lateral directions and 2 mm in the axial direction. Using off-the-shelf hardware, the algorithm can calculate stone positions every 1 s allowing for real-time tracking during lithotripsy.

Impact of repeated extracorporeal shock wave lithotripsy on prepubertal rat kidney

This study aimed to investigate the effects of repeated extracorporeal shock wave lithotripsy (ESWL) on the kidneys of prepubertal and adult rats. Thirty rats were used: 15 were prepubertal (3 weeks of age) with an average body weight of 72.3 ± 3.3 g, and 15 were adults with of 265 ± 11.3 g. The prepubertal and adult rats were separately and randomly allocated to three groups, each consisting of five rats. Following anesthetization, the left kidney of each rat in each group received shock waves in one, two, or three sessions separated by 72 h. The rats in each group were killed 72 h after the last ESWL session, and both kidneys were harvested; the right kidney was used as the control. Renal injury was examined with histological analysis, immunohistochemistry, and Western blot to detecting the expression of heat-shock protein-70, tumor necrosis factor-alpha-α, intercellular adhesion molecule-1, and monocyte chemoattractant protein-1 as markers of renal damage. All of these markers were similarly increased with increased ESWL sessions in both age groups. Histological analysis revealed more serious fibrosis and inflammation in the ESWL-treated kidneys in both groups than in the controls, with the damage increasing with increasing numbers of sessions. ESWL on the kidney increased renal damage according to the number of sessions in both age groups of rats, and the effects of ESWL on renal injury were similar in the two groups. However, there were generally no significant differences in the effects of ESWL on molecular indicators of renal injury between prepubertal and adult rats.

Mechanical and Biological Effects of Ultrasound: A Review of Present Knowledge

Ultrasound is widely used for medical diagnosis and increasingly for therapeutic purposes. An understanding of the bio-effects of sonography is important for clinicians and scientists working in the field because permanent damage to biological tissues can occur at high levels of exposure. Here the underlying principles of thermal mechanisms and the physical interactions of ultrasound with biological tissues are reviewed. Adverse health effects derived from cellular studies, animal studies and clinical reports are reviewed to provide insight into the in vitro and in vivo bio-effects of ultrasound.

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Zusammenfassung. Wir berichten über einen 54-jährigen Mann, der sich wegen einer schmerzhaften Wadenschwellung notfallmässig in der Sprechstunde meldete. Der initiale Verdacht auf eine tiefe Venenthrombose konnte nicht bestätigt werden, es zeigte sich ein Hämatom in der Muskulatur der Wade. Die genaue Anamnese ergab, dass das Hämatom durch die Anwendung einer extrakorporalen Stosswellentherapie durch den Physiotherapeuten iatrogen bedingt war.

Safety and efficacy of extracorporeal shock wave therapy (ESWT) in calcinosis cutis associated with systemic sclerosis

OBJECTIVES

Calcinosis cutis is a frequent, difficult to treat manifestation of systemic sclerosis (SSc) associated with high morbidity. The aim of this prospective, controlled, monocentric study was to assess safety and efficacy of extracorporeal shock wave therapy (ESWT) for calcinosis cutis of the finger in SSc patients.

METHODS

A 12-week proof of concept study in which 4 SSc patients with calcinosis cutis were treated at one painful finger with high-energy, focused ESWT, in 3 sessions with one-week interval between each session. A second, untreated finger, served as control. The outcome parameters were: change in pain, change in size of calcification measured by ultrasound (US) and computed tomography (CT) and of the force by pressing the finger against a Dolorimeter.

RESULTS

Pain was reduced (by 91% and 60%) in the treated finger in two out of four patients. There was no change in the control fingers. The size of the calcinosis in the treated finger was reduced in three (US) and four patients (CT). Inter-assessor agreement was acceptable for US volume measures (ICC=0.863).

CONCLUSIONS

We could show promising evidence for safety and efficacy of ESWT for chronic, treatment resistant calcinosis cutis in SSc patients, thus justifying the initiation of larger multicentre controlled trials.

Thermomechanical effects caused by heavy ions propagating in tissue

The thermomechanical effects caused by ions propagating in tissue are discussed. Large energy densities in small regions surrounding ion paths cause shock waves propagating in tissue. The strength of the shock waves depends on the linear energy transfer. Molecular dynamics simulations help in determining the necessary strength of shock waves in order for the stresses caused by them to directly produce DNA strand breaks. At much smaller values of linear energy transfer, the shock waves may be instrumental in propagating reactive species formed close to the ion's path to large distances, successfully competing with diffusion.

Underwater blast injury: a review of standards

The first cases of underwater blast injury appeared in the scientific literature in 1917, and thousands of service members and civilians were injured or killed by underwater blast during WWII. The prevalence of underwater blast injuries and occupational blasting needs led to the development of many safety standards to prevent injury or death. Most of these standards were not supported by experimental data or testing. In this review, we describe existing standards, discuss their origins, and we comprehensively compare their prescriptions across standards. Surprisingly, we found that most safety standards had little or no scientific basis, and prescriptions across standards often varied by at least an order of magnitude. Many published standards traced back to a US Navy 500 psi guideline, which was intended to provide a peak pressure at which injuries were likely to occur. This standard itself seems to have been based upon a completely unfounded assertion that has propagated throughout the literature in subsequent years. Based on the limitations of the standards discussed, we outline future directions for underwater blast injury research, such as the compilation of epidemiological data to examine actual injury risk by human beings subjected to underwater blasts.

Dependence of thresholds for pulmonary capillary hemorrhage on diagnostic ultrasound frequency

Pulmonary ultrasound examination has become routine for diagnosis in many clinical and point-of-care medical settings. However, the phenomenon of pulmonary capillary hemorrhage (PCH) induction during diagnostic ultrasound imaging presents a poorly understood risk factor. PCH was observed in anesthetized rats exposed to 1.5-, 4.5- and 12.0-MHz diagnostic ultrasound to investigate the frequency dependence of PCH thresholds. PCH was detected in the ultrasound images as growing comet tail artifacts and was assessed using photographs of the surface of excised lungs. Previous photographs acquired after exposure to 7.6-MHz diagnostic ultrasound were included for analysis. In addition, at each frequency we measured dosimetric parameters, including peak rarefactional pressure amplitude and spatial peak, pulse average intensity attenuated by rat chest wall samples. Peak rarefactional pressure amplitude thresholds determined at each frequency, based on the proportion of PCH in groups of five rats, were 1.03 ± 0.02, 1.28 ± 0.14, 1.18 ± 0.12 and 1.36 ± 0.15 MPa at 1.5, 4.5, 7.6 and 12.0 MHz, respectively. Although the PCH lesions decreased in size with increasing ultrasonic frequency, owing to the smaller beam widths and scan lengths, the peak rarefactional pressure amplitude thresholds remained approximately constant. This dependence was different from that of the mechanical index, which indicates a need for a specific dosimetric parameter for safety guidance in pulmonary ultrasound.

Anesthetic techniques influence the induction of pulmonary capillary hemorrhage during diagnostic ultrasound scanning in rats

OBJECTIVES

Pulmonary capillary hemorrhage can be induced by diagnostic ultrasound (US) during direct pulmonary US scanning in rats. The influence of specific anesthetic techniques on this bioeffect was examined.

METHODS

Ketamine plus xylazine has been used previously. In this study, the influence of intraperitoneal injections of ketamine and pentobarbital, inhalational isoflurane, and the supplemental use of xylazine with ketamine and isoflurane was tested. A diagnostic US machine with a 7.6-MHz linear array was used to image the right lung of anesthetized rats in a warmed water bath at different mechanical index (MI) settings. Pulmonary capillary hemorrhage was assessed by measuring comet tail artifacts in the image and by morphometry of the hemorrhagic areas on excised lungs.

RESULTS

Pulmonary capillary hemorrhage was greatest for pentobarbital, lower for inhalational isoflurane, and lowest for ketamine anesthesia, with occurrence thresholds at MIs of about 0.44, 0.8, and 0.8, respectively. Addition of xylazine produced a substantial increase in hemorrhage and a significant proportion of hemorrhage occurrence for ketamine at an MI of 0.7 (P < .01) and for isoflurane at an MI of 0.52 (P < .01).

CONCLUSIONS

Ketamine plus xylazine and pentobarbital yield lower thresholds than ketamine or isoflurane alone by nearly a factor of 2 in MI. These results suggest that the choice of the anesthetic agent substantially modifies the relative risks of pulmonary capillary hemorrhage from pulmonary US.

Is quantitative diffusion-weighted MRI a valuable technique for the detection of changes in kidneys after extracorporeal shock wave lithotripsy?

OBJECTIVE

The aim of this study was to evaluate the capability and the reliability of diffusion-weighted imaging (DWI) in the changes of kidneys occurring after extracorporeal shock wave lithotripsy (ESWL) treatment for renal stones.

MATERIALS AND METHODS

A total of 32 patients who underwent ESWL treatment for renal stone disease between June and December 2011 were enrolled in this prospective study. Color Doppler ultrasonography (CDUS) and DWI were performed before and within 24 hours after ESWL. DWI was obtained with b factors of 0, 500 and 1000 s/ mm2 at 1.5 T MRI. Each of Resistive index (RI) and ADC values were calculated from the three regions of renal upper, middle and lower zones for both of the affected and contralateral kidneys. Paired sample t test was used for statistical analyses.

RESULTS

After ESWL, the treated kidneys had statistically significant lower ADC values in all different regions compared with previous renal images. The best discriminative parameter was signal intensity with a b value of 1000 s/mm2. The changes of DWI after ESWL were noteworthy in the middle of the treated kidney (p < 0.01). There were no significant difference between RI values in all regions of treated and contralateral kidneys before and after treatment with ESWL (p>0.05).

CONCLUSION

DWI is a valuable technique enables the detection of changes in DWI after ESWL treatment that may provide useful information in prediction of renal damage by shock waves, even CDUS is normal.

Characteristics of laser-induced shock wave injury to the inner ear of rats

Recently, the number of blast injuries of the inner ear has increased in the general population. In blast-induced inner ear injury, a shock wave (SW) component in the blast wave is considered to play an important role in sensorineural hearing loss. However, the mechanisms by which an SW affects inner ear tissue remain largely unknown. We aimed to establish a new animal model for SW-induced inner ear injury by using laser-induced SWs (LISWs) on rats. The LISWs were generated by irradiating an elastic laser target with 694-nm nanosecond pulses of a ruby laser. After LISW application to the cochlea through bone conduction, auditory measurements revealed the presence of inner ear dysfunction, the extent of which depended on LISW overpressure. A significantly lower survival rate of hair cells and spiral ganglion neurons, as well as severe oxidative damage, were observed in the inner ear exposed to an LISW. Although considerable differences in the pressure characteristics exist between LISWs and SWs in real blast waves, the functional and morphological changes shown by the present LISW-based model were similar to those observed in real blast-induced injury. Thus, our animal model is expected to be useful for laboratory-based research of blast-induced inner ear injury.

A heuristic model of stone comminution in shock wave lithotripsy

A heuristic model is presented to describe the overall progression of stone comminution in shock wave lithotripsy (SWL), accounting for the effects of shock wave dose and the average peak pressure, P+(avg), incident on the stone during the treatment. The model is developed through adaptation of the Weibull theory for brittle fracture, incorporating threshold values in dose and P+(avg) that are required to initiate fragmentation. The model is validated against experimental data of stone comminution from two stone types (hard and soft BegoStone) obtained at various positions in lithotripter fields produced by two shock wave sources of different beam width and pulse profile both in water and in 1,3-butanediol (which suppresses cavitation). Subsequently, the model is used to assess the performance of a newly developed acoustic lens for electromagnetic lithotripters in comparison with its original counterpart both under static and simulated respiratory motion. The results have demonstrated the predictive value of this heuristic model in elucidating the physical basis for improved performance of the new lens. The model also provides a rationale for the selection of SWL treatment protocols to achieve effective stone comminution without elevating the risk of tissue injury.

A pilot study to assess markers of renal damage in the rodent kidney after exposure to 7 MHz ultrasound pulse sequences designed to cause microbubble translation and disruption

Acoustic radiation force has been proposed as a mechanism to enhance microbubble concentration for therapeutic and molecular imaging applications. It is hypothesized that once microbubbles are localized, bursting them with acoustic pressure could result in local drug delivery. It is known that low-frequency, high-amplitude acoustic energy combined with cavitation nuclei can result in bioeffects. However, little is known about the bioeffects potential of acoustic parameters involved in radiation force and microbubble destruction pulse sequences applied at higher frequencies. In this pilot study, rat kidneys are exposed to high-duty cycle, low-amplitude pulse sequences known to cause substantial bubble translation due to radiation force, as well as high-amplitude short pulse sequences known to cause microbubble destruction. Both studies are performed at 7 MHz on a clinical ultrasound system, and implemented in three-dimensions (3-D) for entire kidney exposure. Analysis of biomarkers of renal injury and renal histopathology indicate that there was no significant renal damage due to these ultrasound parameters in conjunction with microbubbles within the study group.

Effect of extracorporeal shockwave treatment on the melanogenic activity of cultured melanocytes

In addition to the traditional lithotripsy treatment, extracorporeal shockwaves (ESWs) have been shown to be effective in the treatment of certain musculoskeletal disorders and in enhancing skin flap neovascularization. However, relatively little is known about its effect on melanocytes. To investigate its effect on the melanogenic activity of cultured melanocytes, mouse B16F10 melanocytes were treated with defocused ESWs of different energies (15, 21, and 27 kV) and at different doses (300 and 600 impulses). Cell viability was measured 1 and 24 h after treatment. Melanin content was measured and compared against a standard curve generated with fungal melanin. Cellular tyrosinase activity was calculated with the 3,4-dihydroxyphenylalanine (DOPA) oxidase assay. The results demonstrated that ESW treatment reduced cell viability. Our results also indicated that the overall decrease in cell viability lasted for 6 days. After ESW treatment with 300 or 600 impulses at 21 kV, no significant change in melanin content or tyrosinase activity of the B16F10 melanocytes was noted as compared to those of the control. The present study suggests that ESW treatment does not alter the melanogenic activity of the cultured melanocytes.

A multi-mode shock tube for investigation of blast-induced traumatic brain injury

Blast-induced mild traumatic brain injury (bTBI) has become increasingly common in recent military conflicts. The mechanisms by which non-impact blast exposure results in bTBI are incompletely understood. Current small animal bTBI models predominantly utilize compressed air-driven membrane rupture as their blast wave source, while large animal models use chemical explosives. The pressure-time signature of each blast mode is unique, making it difficult to evaluate the contributions of the different components of the blast wave to bTBI when using a single blast source. We utilized a multi-mode shock tube, the McMillan blast device, capable of utilizing compressed air- and compressed helium-driven membrane rupture, and the explosives oxyhydrogen and cyclotrimethylenetrinitramine (RDX, the primary component of C-4 plastic explosives) as the driving source. At similar maximal blast overpressures, the positive pressure phase of compressed air-driven blasts was longer, and the positive impulse was greater, than those observed for shockwaves produced by other driving sources. Helium-driven shockwaves more closely resembled RDX blasts, but by displacing air created a hypoxic environment within the shock tube. Pressure-time traces from oxyhydrogen-driven shockwaves were very similar those produced by RDX, although they resulted in elevated carbon monoxide levels due to combustion of the polyethylene bag used to contain the gases within the shock tube prior to detonation. Rats exposed to compressed air-driven blasts had more pronounced vascular damage than those exposed to oxyhydrogen-driven blasts of the same peak overpressure, indicating that differences in blast wave characteristics other than peak overpressure may influence the extent of bTBI. Use of this multi-mode shock tube in small animal models will enable comparison of the extent of brain injury with the pressure-time signature produced using each blast mode, facilitating evaluation of the blast wave components contributing to bTBI.

[The disguised face of blast injuries: shock waves]

BACKGROUND

The increase in terrorist attacks has brought a profound and new knowledge of blast injuries. In order to improve our knowledge regarding the mechanisms of blast injuries, we analyzed the effects of shock waves.

METHODS

100 g TNT and 1000 g C4 were detonated and recorded by high-speed camera. Blast wind, shock wave and shrapnel speeds were calculated, and final condition of the target was examined.

RESULTS

A flash ball appeared first followed by the shock wave. Finally, blast wind occurred and shrapnel was distributed. The macroscopic structure of targets was not affected by the shock wave but was affected by shrapnel and blast wind. Shock waves created a transparent ballistic gel inside the target mat by changing its microscopic structure. The speed of the shock wave was 6482-7194 m/sn and shrapnel speed was 1420-1752 m/sn.

CONCLUSION

Shock waves especially affect the air-filled organs and cause lung injury, acute respiratory distress syndrome, and intestinal and eardrum perforation. Blast wind destroys targets due to its high speed and high density. The main cause of mortality is shrapnel injury. The high temperature created by the explosion causes thermal injuries. Being informed of the mechanisms of blast injuries will assist in providing better treatment. Additionally, consideration of all mechanisms of blast injuries will facilitate lower mortality and morbidity rates.

The effect of antibacterial acting extracorporeal shockwaves on bacterial cell integrity

BACKGROUND

Antibacterial effects of extracorporeal shockwaves (ESWs) have been demonstrated in vitro against bacteria under static and dynamic growth conditions. This study assessed the effects of ESWs on the cell wall integrity of bacteria.

MATERIAL/METHODS

Standardized suspensions of Staphylococcus aureus were exposed to various shockwave impulses (2000-12,000) of different energy flux densities (EFD, 0.38-0.96 mJ/mm(2)). Bacterial suspensions of equal concentration that had been permeabilized (to >99%) with isopropanol were used as positive controls. The bacteria of all groups were stained with Sytox Green nucleic acid stain. The fluorescence of the shockwave-treated, permeabilized, and untreated suspensions was measured and compared for bacterial survival, quantified by colony-forming units after plating.

RESULTS

Although ESWs showed a significant energy-dependent antibacterial effect that reduced CFUs in the treated suspensions by between 56% and 99%, only maximum energies (4000 impulses at 0.96 mJ/mm(2) and 12,000 impulses at 0.59 mJ/mm(2)) were followed by a significant increase in fluorescence compared with the untreated control (p<0.05). However, the fluorescence of these treated groups was still far less than that of the alcohol-permeabilized positive control groups (p<0.05). Lower energies and impulse rates did not show increased intracellular uptake of the fluorescent dye (p>0.05).

CONCLUSIONS

This is the first study to assess bacterial cell wall permeability after ESW treatment. It was found that the permeabilization of bacterial cells after ESW treatment was far less than expected due to the corresponding antibacterial effect. Other mechanisms, such as intracellular effects, might be involved in bacterial killing after ESWs and still must be elucidated.

Primary Osteoblasts Response to Shock Wave Therapy Using Different Parameters

Over the past decade extracorporeal shock-wave therapy (ESWT) has been increasingly applied to orthopaedic and musculoskeletal pathologies, the aim of this study was to assess how the energy density of the shock waves and the number of impulses affect viability, differentiation and synthetic activity of osteoblasts. Primary sheep osteoblasts cultures were treated with ESWT with an electro-hydraulic shock wave generator by selecting three different energy levels (14-21-28 kV corresponding at 0.15-0.31-0.40 mJ/mm2) and two different total numbers of impulses (500, 1000) for each level. At the end of treatment, cell counts and viability were recorded. Cells were then cultivated for 48 hours starting from a concentration of 1 x 10(4) cells/ml. The biological activity and viability were evaluated at 24 and 48 hours after treatment. No cytodestructive effects were observed in Group A, while a cytodestructive effect of ESWT was seen in cultures receiving the highest energy treatments. The different shock wave treatment induced differences in MTT assays after 24 and 48 hours, in particular the highest level showed a detrimental effect on cell respiration at both experimental times as compared to the Control Group and the protein metabolism was generally depressed by ESWT with impulses at the highest energy level. After 24 hours such effect further increased with the growing number of impulses. The lowest energy level appeared to significantly improve the metabolic parameter in primary cell cultures as compared to controls when 500 impulses were selected. The current study has demonstrated that one of the most important aspects to be considered is not the total number of impulses used but the energy level of the shock waves, thus confirming that ESWT has a dose-dependent effect on cells.

Prevention of shockwave induced functional and morphological alterations: an overview

Experimental as well as clinical findings reported in the literature suggest that treatment with shock wave lithotripsy (SWL) causes renal parenchymal damage mainly by generating free radicals through ischaemia/reperfusion injury mechanism. Although SWL-induced renal damage is well tolerated in the majority of healthy cases with no permanent functional and/or morphologic side effects, a subset of patients with certain risk factors requires close attention on this aspect among which the ones with pre-existing renal disorders, urinary tract infection, previous lithotripsy history and solitary kidneys could be mentioned. It is clear that in such patients lowering the number of shock waves (per session) could be beneficial and has been applied by the physicians as the first practical step of diminishing SWL induced parenchymal damage. On the other hand, taking the injurious effects of high energy shock wave (HESW) induced free radical formation on renal parenchyma and subsequent histopathologic alterations into account, physicians searched for some protective agents in an attempt to prevent or at least to limit the extent of the functional as well as the morphologic alterations. Among these agents calcium channel blocking agents (verapamil and nifedipine), antioxidant agents (allopurinol, vitamin E and selenium) and potassium citrate have been used to minimize these adverse effects. Additionally, therapeutic application of these agents on reducing stone recurrence particularly after SWL will gain more importance in the future in order to limit new stone formation in these cases. Lastly, as experimental and clinical studies have demonstrated, combination of anti-oxidants with free radical scavengers may provide superior renal protection against shock wave induced trauma. However, we believe that further investigations are certainly needed to determine the dose-response relationship between the damaging effects of SWL application and the protective role of these agents.

High-energy extracorporeal shock wave therapy as a treatment for chronic noninsertional Achilles tendinopathy

BACKGROUND

High-energy extracorporeal shock wave therapy has been shown to be an effective treatment for chronic insertional Achilles tendinopathy. The results of high-energy shock wave therapy for chronic noninsertional Achilles tendinopathy have not been determined.

HYPOTHESIS

Shock wave therapy is an effective treatment for noninsertional Achilles tendinopathy.

STUDY DESIGN

Case control study; Level of evidence, 3.

METHODS

Thirty-four patients with chronic noninsertional Achilles tendinopathy were treated with a single dose of high-energy shock wave therapy (shock wave therapy group; 3000 shocks; 0.21 mJ/mm(2); total energy flux density, 604 mJ/mm(2)). Thirty-four patients with chronic noninsertional Achilles tendinopathy were treated not with shock wave therapy but with additional forms of nonoperative therapy (control group). All shock wave therapy procedures were performed using regional anesthesia. Evaluation was by change in visual analog score and by Roles and Maudsley score.

RESULTS

One month, 3 months, and 12 months after treatment, the mean visual analog scores for the control and shock wave therapy groups were 8.4 and 4.4 (P < .001), 6.5 and 2.9 (P < .001), and 5.6 and 2.2 (P < .001), respectively. At final follow-up, the number of excellent, good, fair, and poor results for the shock wave therapy and control groups were 12 and 0 (P < .001), 17 and 9 (P < .001), 5 and 17 (P < .001), and 0 and 8 (P < .001), respectively. A chi(2) analysis revealed that the percentage of patients with excellent ("1") or good ("2") Roles and Maudsley scores, that is, successful results, 12 months after treatment was statistically greater in the shock wave therapy group than in the control group (P < .001).

CONCLUSION

Shock wave therapy is an effective treatment for chronic noninsertional Achilles tendinopathy.

A cumulative shear mechanism for tissue damage initiation in shock-wave lithotripsy

Evidence suggests that inertial cavitation plays an important role in the renal injury incurred during shock-wave lithotripsy. However, it is unclear how tissue damage is initiated, and significant injury typically occurs only after a sufficient dose of shock waves. Although it has been suggested that shock-induced shearing might initiate injury, estimates indicate that individual shocks do not produce sufficient shear to do so. In this paper, we hypothesize that the cumulative shear of the many shocks is damaging. This mechanism depends on whether there is sufficient time between shocks for tissue to relax to its unstrained state. We investigate the mechanism with a physics-based simulation model, wherein the basement membranes that define the tubules and vessels in the inner medulla are represented as elastic shells surrounded by viscous fluid. Material properties are estimated from in-vitro tests of renal basement membranes and documented mechanical properties of cells and extracellular gels. Estimates for the net shear deformation from a typical lithotripter shock (approximately 0.1%) are found from a separate dynamic shock simulation. The results suggest that the larger interstitial volume (approximately 40%) near the papilla tip gives the tissue there a relaxation time comparable to clinical shock delivery rates (approximately 1 Hz), thus allowing shear to accumulate. Away from the papilla tip, where the interstitial volume is smaller (approximately 20%), the model tissue relaxes completely before the next shock would be delivered. Implications of the model are that slower delivery rates and broader focal zones should both decrease injury, consistent with some recent observations.

The repeated extracorporeal shock waves and the renal parenchyma injury on normal and diabetic rats

PURPOSE

To assess the effect of repeated extracorporeal shock waves (ESW) on renal parenchyma of normal and diabetic rats.

METHODS

40 normal rats (A) and 40 diabetic rats (B) were assigned for ESW (Direx Tripter X1 - 14 KVA) as follow: A1/B1 and A3/B3 no ESW; A2/B2 one ESW (2,000 SW); A4/B4 two ESW (4,000 SW) in an elapsed 14 days. All the animals were sacrificed 3 days after the ESW and samples of renal parenchyma were histological prepared, stained by H&E. For each animal the frequency of hemorrhage focus (HF) in the subcapsular, interstitial and glomerulus area was calculated (percentage) on 20 randomly histological sections.

RESULTS

No one HF was identified in all normal or diabetic animals without ESW (A1, A3 and B1, B3). In the normal rats the HF frequency was similar to one ESW (subcapsular =15%; interstitial =20% and glomerular =10%) or repeated ESW (subcapsular =25%; interstitial =20%; glomerular=10%). In diabetic rats the occurrence of HF with repeated ESW was more frequent (subcapsular =40%; interstitial =30% and glomerular =10%) than with a single ESW (subcapsular =25%; interstitial =15% and glomerular =15%).

CONCLUSION

A single ESW or a repeated ESW caused a mild and similar damage on renal cortex of normal rats. In diabetic rats the repeated ESW may result in an accumulated damage, especially with focus of hemorrhage in subcapsular and interstitial tissue and glomerulus edema.

Pressure-dependent effect of shock waves on rat brain: induction of neuronal apoptosis mediated by a caspase-dependent pathway

OBJECT

Shock waves have been experimentally applied to various neurosurgical treatments including fragmentation of cerebral emboli, perforation of cyst walls or tissue, and delivery of drugs into cells. Nevertheless, the application of shock waves to clinical neurosurgery remains challenging because the threshold for shock wave-induced brain injury has not been determined. The authors investigated the pressure-dependent effect of shock waves on histological changes of rat brain, focusing especially on apoptosis.

METHODS

Adult male rats were exposed to a single shot of shock waves (produced by silver azide explosion) at overpressures of 1 or 10 MPa after craniotomy. Histological changes were evaluated sequentially by H & E staining and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL). The expression of active caspase-3 and the effect of the nonselective caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (Z-VAD-FMK) were examined to evaluate the contribution of a caspase-dependent pathway to shock wave-induced brain injury. High-overpressure (> 10 MPa) shock wave exposure resulted in contusional hemorrhage associated with a significant increase in TUNEL-positive neurons exhibiting chromatin condensation, nuclear segmentation, and apoptotic bodies. The maximum increase was seen at 24 hours after shock wave application. Low-overpressure (1 MPa) shock wave exposure resulted in spindle-shaped changes in neurons and elongation of nuclei without marked neuronal injury. The administration of Z-VAD-FMK significantly reduced the number of TUNEL-positive cells observed 24 hours after high-overpressure shock wave exposure (p < 0.01). A significant increase in the cytosolic expression of active caspase-3 was evident 24 hours after high-overpressure shock wave application; this increase was prevented by Z-VAD-FMK administration. Double immunofluorescence staining showed that TUNEL-positive cells were exclusively neurons.

CONCLUSIONS

The threshold for shock wave-induced brain injury is speculated to be under 1 MPa, a level that is lower than the threshold for other organs. High-overpressure shock wave exposure results in brain injury, including neuronal apoptosis mediated by a caspase-dependent pathway. This is the first report in which the pressure-dependent effect of shock wave on the histological characteristics of brain tissue is demonstrated.

Immunohistochemical evaluation of substance P and calcitonin gene-related peptide in skin and periosteum after extracorporeal shock wave therapy and radial pressure wave therapy in sheep

OBJECTIVE

To evaluate the effect of focused extracorporeal shock wave therapy (ESWT) and radial pressure wave therapy (RPWT) on immunohistochemical staining for substance P and calcitonin gene-related peptide (CGRP) in the skin and periosteum of sheep.

ANIMALS

36 sheep.

PROCEDURES

All 4 limbs of 36 sheep were treated with ESWT, RPWT, or a sham treatment. For 14 days after treatment, at least 2 sheep were euthanized daily and tissue was harvested for histologic evaluation of nerves via staining for substance P and CGRP in the skin and periosteum.

RESULTS

No effects of ESWT or RPWT were observed on the number of nerves with stain uptake for substance P or CGRP in the skin or periosteum.

CONCLUSIONS AND CLINICAL RELEVANCE

Substance P- and CGRP-containing nerve fibers are not disrupted by EWST or RPWT. Further studies are needed to identify the mechanism of analgesia observed in association with these treatment modalities.

Extracorporeal shock wave treatment for chronic lateral epicondylitis (tennis elbow)

(1) Electrohydraulic, electromagnetic, or piezoelectric devices are used to translate energy into acoustic waves during extracorporeal shock wave treatment (ESWT) for chronic lateral epicondylitis (CLE) of the elbow (elbow tendonitis or tennis elbow). These waves may help to accelerate the healing process via an unknown mechanism. (2) Results from randomized controlled trials have been conflicting. Half of the studies showed statistically significant improvement in pain in the treatment group, and half of the studies had data showing no benefit over placebo for any measured outcomes. (3) Limited evidence shows that ESWT is cheaper than arthroscopic surgery, open surgery, and other conservative therapies, such as steroid infiltrations and physiotherapy, that continue for more than six weeks. (4) The lack of convincing evidence regarding its effectiveness does not support the use of ESWT for CLE.

Extracorporeal shock wave treatment for chronic rotator cuff tendonitis (shoulder pain)

(1) Electrohydraulic, electromagnetic, or piezoelectric devices are used to translate energy into acoustic waves during extracorporeal shock wave treatment (ESWT) for chronic rotator cuff tendonitis (shoulder pain). The acoustic waves may help to accelerate the healing process of chronic rotator cuff tendonitis via an unknown mechanism. (2) ESWT, which is performed as an outpatient procedure, is intended to alleviate the pain due to chronic rotator cuff tendonitis. (3) Limited evidence from a German study indicates that the cost of ESWT for rotator cuff tendonitis is one-fifth to one-seventh the cost of surgical treatment, with longer recovery time and time off work in the surgical treatment group accounting for about two-thirds of the overall cost. (4) The evidence reviewed for this bulletin supports the use of high-energy ESWT for chronic calcific rotator cuff tendonitis, but not for non-calcific rotator cuff tendonitis. High-quality RCTs with larger sample sizes are needed to provide stronger evidence.

Extracorporeal shock wave treatment for chronic plantar fasciitis (heel pain)

(1) Electrohydraulic, electromagnetic, or piezoelectric devices are used to translate energy into acoustic waves during extracorporeal shock wave treatment (ESWT) for chronic plantar fasciitis (or heel pain). These waves may help to accelerate the healing process via an unknown mechanism. (2) ESWT, which is performed as an outpatient procedure, is intended to alleviate the pain due to chronic plantar fasciitis. (3) Results from randomized controlled trials have been conflicting. Six trials reported data that favour ESWT over placebo or conservative treatment for efficacy outcomes, while three trials showed no significant difference between the ESWT group and the placebo group. (4) The lack of convergent findings from randomized trials of ESWT for chronic plantar fasciitis suggests uncertainty about its effectiveness. The evidence reviewed in this bulletin does not support the use of this technology for this condition.

Extracorporeal shockwave therapy versus placebo for the treatment of chronic proximal plantar fasciitis: results of a randomized, placebo-controlled, double-blinded, multicenter intervention trial

Extracorporeal shockwave therapy (ESWT) has demonstrated efficacy in the treatment of recalcitrant proximal plantar fasciitis. The objective of this investigation was to compare the outcomes of participants treated with a new ESWT device with those treated with placebo. A total of 172 volunteer participants were randomized in a 2:1 active-to-placebo ratio in this prospective, double-blind, multicenter trial conducted between October 2003 and December 2004. ESWT (n=115) or placebo control (n=57) was administered on a single occasion without local or systemic anesthesia or sedation, after which follow-up was undertaken. The primary outcomes were the blind assessor's objective, and the participant's subjective assessments of heel pain during the first 3 months of follow-up. Participants were also followed up to 1 year to identify any adverse outcomes that may have been related to the shockwave device. On the visual analog scale, the blind assessor's objective assessment of heel pain displayed a mean reduction of 2.51 in the shockwave group and 1.57 in the placebo group; this difference was statistically significant (P=.045). On the visual analog scale, the participant's self-assessment of heel pain displayed a mean reduction of 3.39 in the shockwave group and 1.78 in the placebo group; this difference was statistically significant (P<.001). No serious adverse events were observed at any time. It was concluded that ESWT was both efficacious and safe for participants with chronic proximal plantar fasciitis that had been unresponsive to exhaustive conservative treatment.

A novel antioxidant agent, astragalosides, prevents shock wave-induced renal oxidative injury in rabbits

Extracorporeal shock-wave lithotripsy (ESWL)-induced renal damage can occur as a result of multiple mechanisms, including small vessel injury and free radical formation. Our previous studies have demonstrated that Astragalus membranaceus (AM), a traditional Chinese herb, could significantly alleviate shock wave-induced renal oxidative injury, and its renoprotective effects were superior to those of varapamil, a calcium antagonist, which were considered to be a powerful agent in treating renal damage during ESWL. However, the effective antioxidant ingredient of this herb in the setting of lithotripsy remains unclear. Astragalosides, the major components of AM, was demonstrated to have superior antioxidation properties both in vitro and in vivo. Therefore, in this study we further investigate the potential effects of astragalosides on the shock wave-induced oxidative stress in rabbit kidney. Thirty male rabbits were randomly assigned to two groups, each consisting of 15 rabbits: (1) control group, (2) astragaloside-treated group. Each group of animals underwent 1,500 shock waves to the right kidney. Peripheral blood, urine and kidney tissue samples were collected pre- and post-ESWL. The level of urinary N-acetyl-beta-glucosaminidase (NAG), serum creatinine, serum or homogenates malondialdehyde (MDA) and superoxide dismutase (SOD), respectively, were detected. Histological alterations were also examined through light microcopy and transmission electron microscopy. In the control group, shock wave significantly increased the level of MDA and decreased SOD activity in both blood and renal homogenates (P<0.05, respectively). The comparison between the control and astragalosides group demonstrated that astragalosides could significantly decrease the level of MDA (P<0.05) and inhibit the decline of SOD activity (P<0.05). After exposure to shock waves, the activity of urinary NAG increased significantly in the control group (P<0.05). However, the concentration of serum creatinine did not change significantly. The comparison between the control and astragalosides group demonstrated that astragalosides significantly reduced the shock wave-induced leakage of NAG into the urine (P<0.05). Histological examination also showed that renal morphological impairments were much milder in astragaloside-treated rabbits than those of the control group. Our results indicated that astragaloside treatment provided significant protection against shock wave-induced renal oxidative injury.

Assessment of scintigraphic and thermographic changes after focused extracorporeal shock wave therapy on the origin of the suspensory ligament and the fourth metatarsal bone in horses without lameness

OBJECTIVE

To monitor the effect of focused extra-corporeal shock wave therapy (ESWT) on bone and bone-tendon junction of horses without lameness by use of nuclear scintigraphy and thermography.

ANIMALS

6 warmblood horses without lameness.

PROCEDURE

The origin of the suspensory ligament at the metacarpus (OSL-MC) and the fourth metatarsal bone were treated at 2 time points (days 0 and 16) with 2,000 shocks applied by a focused ESWT device at an energy flux density of 0.15 mJ/mm2. One forelimb and 1 hind limb were treated, and the contralateral limbs served as controls. To document the effect of focused ESWT, nuclear scintigraphy was performed on days -1, 3, 16 (before second ESWT), and 19. Thermography was performed on days -1, 0 (1 hour after first ESWT), 1, 3, 8, 16 (twice; before and 1 hour after second ESWT), and 19. On days 3, 16 (first scans), and 19, thermography was performed before scintigraphy.

RESULTS

Scintigraphically, significant variations in radiopharmaceutical activity at the OSL-MC were detected in treatment and control limbs. No significant differences, however, in mean temperature or radiopharmaceutical activity could be detected by use of thermography or nuclear scintigraphy, respectively, between the treatment and control limbs at any time point in response to ESWT.

CONCLUSIONS AND CLINICAL RELEVANCE

After 2 treatments of focused ESWT, no physiologic effect on the studied structures could be demonstrated by use of nuclear scintigraphy or thermography. Results of this study indicate that at currently used ESWT settings, no damage to the bone or bone-tendon junction should occur.

The isolated perfused kidney: an in vitro test system for evaluation of renal tissue damage induced by high-energy shockwaves sources

Most of our knowledge of shockwave-induced renal damage is based on animal experiments and clinical observation. We developed a tissue model using isolated porcine kidneys perfused with Berliner Blau dye in physiologic saline using a Ureteromat Perez-Castro peristaltic pump connected to the renal artery. Reproducible results were obtained under a variety of experimental conditions. Further refinements of the model might consist of interposition of tissue layers in the shockwave path or simulation of ventilatory movements.

The role of extracorporeal shock wave on plantar fasciitis

Extracorporeal shock wave therapy for chronic plantar fasciitis has been under investigation since its advent in the early 1990s. Its use has been approved by the U.S. Food and Drug Administration; however, much controversy exists surrounding its mechanism of action, treatment protocols, and clinical efficacy. This article reviews some of the existing theories, opinions, and data in an attempt to summarize the current role that shock wave therapy plays in the treatment of plantar fasciitis.

Osseous lesion of the calcaneus following the use of shock wave therapy in a horse

An 8-year-old Dutch warmblood gelding was presented with a mechanical lameness (2/10) because of the presence of a soft tissue injury on the top of the right tuber calcanei. Plain radiographs of the tarsus demonstrated the presence of soft tissue swelling caudal to the right tuber calcanei, without osseous involvement, and ultrasonography revealed excessive scar tissue within and around the superficial digital flexor tendon. Extra-corporeal shock wave therapy was applied on the right hock to decrease the amount of scar tissue. One month after the therapy the lameness was greater (3/10) and a marginal increase in the size of the swelling was found. Periosteal new bone formation associated with an ill-defined radiolucent area and two bony fragments were detected radiographically at the caudo-proximal aspect of the right tuber calcanei. A blister containing oil of croton, camphor, pine and thyme, turpentine and cantharides was applied on the right calcaneus. Twenty days after blister application, the size of the swelling had been reduced by 50% and the degree of lameness had also been decreased (1/10). On clinical re-evaluation 6 months after treatment, the degree of lameness was stable (1/10) and flexion test of the limb was negative.

Shock wave therapy for chronic Achilles tendon pain: a randomized placebo-controlled trial

Shock wave therapy has been used for treatment of several soft tissue disorders that are characterized by chronic pain. We sought to determine if shock wave therapy reduces chronic Achilles tendon pain. Forty-nine patients were enrolled in a double-blind randomized placebo-controlled trial. Each patient was treated once a month for 3 months. The primary outcome measure was a reduction in Achilles tendon pain during walking. At the end of the trial, we found no difference in pain relief between the shock wave therapy group and the control group. There were two patients (62 years and 65 years) with tendon ruptures in the treatment group, suggesting caution when treating older patients. These results provide no support for the use of shock wave therapy for treatment of patients with chronic Achilles tendon pain. However, the confidence intervals include the potential for a clinically relevant treatment effect.

LEVEL OF EVIDENCE

Therapeutic study, Level I (systematic review of Level I RCTs-and study results were homogenous). See the Guidelines for Authors for a complete description of levels of evidence.

Extracorporeal shock wave therapy without local anesthesia for chronic lateral epicondylitis

BACKGROUND

The use of extracorporeal shock wave therapy for the treatment of lateral epicondylitis is controversial. The purpose of this study was to evaluate the use of extracorporeal shock wave therapy without local anesthesia to treat chronic lateral epicondylitis.

METHODS

One hundred and fourteen patients with a minimum six-month history of lateral epicondylitis that was unresponsive to conventional therapy were randomized into double-blind active treatment and placebo groups. The protocol consisted of three weekly treatments of either low-dose shock wave therapy without anesthetic or a sham treatment. Patients had a physical examination, including provocation testing and dynamometry, at one, four, eight, and twelve weeks and at six and twelve months after treatment. Radiographs, laboratory studies, and electrocardiograms were also evaluated prior to participation and at twelve weeks. A visual analog scale was used to evaluate pain, and an upper extremity functional scale was used to assess function. Crossover to active treatment was initiated for nonresponsive patients who had received the placebo and met the inclusion criteria after twelve weeks.

RESULTS

A total of 108 of the 114 randomized patients completed all treatments and the twelve weeks of follow-up required by the protocol. Sixty-one patients completed one year of follow-up, whereas thirty-four patients crossed over to receive active treatment. A significant difference (p = 0.001) in pain reduction was observed at twelve weeks in the intent-to-treat cohort, with an improvement in the pain score of at least 50% seen in 61% (thirty-four) of the fifty-six patients in the active treatment group who were treated according to protocol compared with 29% (seventeen) of the fifty-eight subjects in the placebo group. This improvement persisted in those followed to one year. Functional activity scores, activity-specific evaluation, and the overall impression of the disease state all showed significant improvement as well (p < 0.05). Crossover patients also showed significant improvement after twelve weeks of active treatment, with 56% (nineteen of thirty-four) achieving an improvement in the pain score of at least 50% (p < 0.0001).

CONCLUSIONS

These results demonstrate that low-dose shock wave therapy without anesthetic is a safe and effective treatment for chronic lateral epicondylitis.

[Focused extracorporeal shock wave therapy in an isolated calcification in the equine ligamentum nuchae--case report]

In recent years extracorporeal shock wave therapy (ESWT) is used in veterinary medicine especially in equine orthopedics. Different ESWT generators are commonly used in equine medicine with varying energy density and depth of penetration. The presented case report described the treatment of a ligamentum nuchae calcification with focused extracorporeal shock wave therapy with SONOCUR Plus generator combined with SONOLINE Prima ultrasound. Negligible adverse effects, the non-invasive character of the treatment, the time-saving therapy, and the positive results make the focused extracorporeal shock wave therapy to an useful application.

Astragalus membranaceus reduces free radical-mediated injury to renal tubules in rabbits receiving high-energy shock waves

BACKGROUND

Recent studies have revealed the important role of free radicals in renal damage induced by high-energy shock waves (HESW). This study aimed at investigating the effects of Astragalus membranaceus, a traditional Chinese medicinal herb, on free radical-mediated HESW-induced damage to renal tubules in a live rabbit model.

METHODS

Forty-five healthy male New Zealand white rabbits were randomly divided into three groups: control group (n = 15), sham group (n = 15), and herb-treated group (n = 15). Three days prior to HESW application, the controls received verapamil (0.4 mg/kg), the shams received physiological saline (20 ml), and the herb-treated animals received Astragalus membranaceus (2.4 g/kg) intravenously. HESW (1500 shocks, 18 kV) was applied to the right kidneys of all anesthetized rabbits. We measured superoxide dismutase (SOD) and malondialdehyde (MDA) levels before and after shock treatment in blood and kidney homogenates. Histopathological changes were also observed.

RESULTS

MDA levels increased and SOD activity decreased significantly in the sham group (P < 0.05 for both) after shock treatment. MDA levels showed a much less increase in the controls (P < 0.05) and did not increase to statistically significant levels in the group receiving Astragalus membranaceus (P > 0.05). SOD values were significantly higher in the controls than in the shams (P < 0.05). By contrast, SOD levels recovered rapidly in the rabbits receiving Astragalus membranaceus, reaching a nadir within 24 hours, and returning to baseline more quickly than in control and sham rabbits (P < 0.05). Histopathological examinations showed that renal tubular damage in the controls was less severe than in the shams, while damage in the Astragalus membranaceus group was even more mild, with rapid recovery in comparison with the controls.

CONCLUSION

This study provides preliminary evidence indicating that Astragalus membranaceus has strong protective effects on free radical-mediated renal tubular damage induced by HESW and that these effects are superior to the effects of verapamil.

The effects of extracorporeal shock waves on the rat Achilles tendon: is there a critical dose for tissue injury?

INTRODUCTION

Extracorporeal shock waves (ESW) have been extensively studied in the field of orthopedics. Experimental and focused, well-designed clinical studies have suggested the clinical utilisation of ESW in several pathologies including delayed bone union, tennis elbow, and plantar fasciitis. However, the unwanted detrimental effects of ESW on various tissues have been questioned by some authors. In this experimental study, the effects of ESW were investigated at different intensity applications on the Achilles tendons of rat.

MATERIALS AND METHODS

A total of 32 adult Wistar albino rats was divided into four groups. The first three groups received 1000 impulses of 0.15 mJ/mm2, 1500 impulses of 0.15 mJ/mm2, and 2000 impulses of 0.20 mJ/mm2, respectively. The last group was kept as the control group. Subsequently, Achilles tendons were harvested for histological studies from all rats at the 3rd week after a single application of ESW.

RESULTS

There were no histological abnormalities observed in the Achilles tendons of the first two groups compared with the control group. No alteration in the histological configuration was observed, and consequently the pathologist who had been blinded could not differentiate these rats from the control group by light microscopy. However, in the high intensity group (2000 impulses of 0.20 mJ/mm2), grade II and III disorganisation of collagen fibers was noticed in 7 out of 8 rats, which was not detected in any of the rats from the first two groups (p<0.05). Consequently, the pathologist could distinguish the majority of the rats (7 out of 8) of this group from the remaining ones. Meanwhile, grade I lymphocyte infiltration was observed in some sections of the rats receiving the highest ESW dose.

CONCLUSION

This study confirms that ESW application at high intensity is associated with detrimental tissue effects. Additionally, it was suggested that the extent of tissue injury caused by ESW is dose-related.

Cavitation bubble cluster activity in the breakage of kidney stones by lithotripter shockwaves

BACKGROUND AND PURPOSE

There is strong evidence that cavitation bubble activity contributes to stone breakage and that shockwave-bubble interactions are involved in the tissue trauma associated with shockwave lithotripsy. Cavitation control may thus be a way to improve lithotripsy.

MATERIALS AND METHODS

High-speed photography was used to analyze cavitation bubble activity at the surface of artificial and natural kidney stones during exposure to lithotripter shockwaves in vitro.

RESULTS

Numerous individual bubbles formed on the surfaces of stones, but these bubbles did not remain independent but rather combined to form clusters. Bubble clusters formed at the proximal and distal ends and at the sides of stones. Each cluster collapsed to a narrow point of impact. Collapse of the proximal cluster eroded the leading face of the stone, and the collapse of clusters at the sides of stones appeared to contribute to the growth of cracks. Collapse of the distal cluster caused minimal damage.

CONCLUSION

Cavitation-mediated damage to stones is attributable, not to the action of solitary bubbles, but to the growth and collapse of bubble clusters.

Does shock wave lithotripsy of renal stones cause cardiac muscle injury? A troponin I-based study

OBJECTIVES

To investigate whether shock wave lithotripsy (SWL) causes cardiac muscle injury that alters the levels of troponin I plasma, a cardio-specific enzyme shown to be useful in diagnosing cardiac muscle injury because of its high specificity.

METHODS

Patients treated by SWL for renal stones participated in the study. They had undergone a baseline 12-lead electrocardiogram (ECG) a few days earlier. One day after SWL, they were queried about any chest discomfort, blood was drawn for evaluation of troponin I and creatine kinase with isoenzymes (CK-MB), and an ECG was carried out.

RESULTS

Thirty-two patients (21 men and 11 women, mean age +/- SD 51.0 +/- 10.6 years) comprised the study group. Fourteen SWL treatments were on the right side and 18 on the left. The mean number of shock waves was 2859 +/- 202. The mean time to evaluation after SWL was 22.3 +/- 1.3 hours. None of the patients reported chest discomfort. The mean value was 6.6 +/- 9.2 mU/mL for CK-MB and 0.02 l +/- 0.04 ng/mL for troponin I. No ECG changes suggestive of myocardial injury were evident. None of the 5 patients who experienced ventricular extrasystoles during SWL had any evidence of cardiac muscle injury.

CONCLUSIONS

We evaluated the symptoms, perioperative ECG changes, and cardiac troponin I and CK-MB plasma levels in patients who underwent SWL for renal stones and did not identify any myocardial damage. Troponin I plasma levels were not elevated after this procedure and, therefore, remain suitable for evaluation of patients complaining of chest pain after SWL.