Pretreatment with low-energy shock waves reduces the renal oxidative stress and inflammation caused by high-energy shock wave lithotripsy

Renal Protection Phenomenon Observed in a Porcine Model After Electromagnetic Lithotripsy Using a Treatment Pause

Purpose: Pretreating the kidney with 100 low-energy shock waves (SWs) with a time pause before delivering a clinical dose of SWs (Dornier HM-3, 2000 SWs, 24 kV, and 120 SWs/min) has been shown to significantly reduce the size of the hemorrhagic lesion produced in that treated kidney, compared to a protocol without pretreatment. It has been assumed that a similar reduction in injury will occur with lithotripters other than the HM-3, but experiments to confirm this assumption are lacking. In this study, we sought to verify that the lesion protection phenomenon also occurs in a lithotripter using an electromagnetic shock source and dry-head coupling. Materials and Methods: Eleven female pigs were placed in a Dornier Compact S lithotripter where the left kidney of each animal was targeted for lithotripsy treatment. Some kidneys received 2500 SWs at power level (PL) = 5 (120 SWs/min) while some kidneys were pretreated with 100 SWs at PL = 1, with a 3-minute time pause, followed immediately by 2500 SWs at PL = 5 (120 SWs/min). Lesion size analysis was performed to assess the volume of hemorrhagic tissue injury created by each treatment regimen (% functional renal volume). Results: Lesion size fell by 85% (p = 0.01) in the 100 SW pretreatment group compared to the injury produced by a regimen without pretreatment. Conclusions: The results suggest that the treatment pause protection phenomenon occurs with a Dornier Compact S, a machine distinctly different from the Dornier HM-3. This result also suggests that this phenomenon may be observed generally in SW lithotripters.

Low-energy shock wave pretreatment recruit circulating endothelial progenitor cells to attenuate renal ischaemia reperfusion injury

Low‐energy shock wave (LESW) has been recognized as a promising non‐invasive intervention to prevent the organs or tissues against ischaemia reperfusion injury (IRI), whereas its effect on kidney injury is rarely explored. To investigate the protective role of pretreatment with LESW on renal IRI in rats, animals were randomly divided into Sham, LESW, IRI and LESW + IRI groups. At 4, 12, 24 hours and 3 and 7 days after reperfusion, serum samples and renal tissues were harvested for performing the analysis of renal function, histopathology, immunohistochemistry, flow cytometry and Western blot, as well as enzyme‐linked immunosorbent assay. Moreover, circulating endothelial progenitor cells (EPCs) were isolated, labelled with fluorescent dye and injected by tail vein. The fluorescent signals of EPCs were detected using fluorescence microscope and in vivo imaging system to track the distribution of injected circulating EPCs. Results showed that pretreatment with LESW could significantly reduce kidney injury biomarkers, tubular damage, and cell apoptosis, and promote cell proliferation and vascularization in IRI kidneys. The renoprotective role of LESW pretreatment would be attributed to the remarkably increased EPCs in the treated kidneys, part of which were recruited from circulation through SDF‐1/CXCR7 pathway. In conclusion, pretreatment with LESW could increase the recruitment of circulating EPCs to attenuate and repair renal IRI.

Ultraslow full-power shock wave lithotripsy versus slow power-ramping shock wave lithotripsy in stones with high attenuation value: A randomized comparative study

OBJECTIVES

To compare the efficacy and safety of ultraslow full-power versus slow rate, power-ramping shock wave lithotripsy in the management of stones with a high attenuation value.

METHODS

This was a randomized comparative study enrolling patients with single high attenuation value (≥1000 Hounsfield unit) stones (≤3 cm) between September 2015 and May 2018. Patients with skin-to-stone distance >11 cm or body mass index >30 kg/m² were excluded. Electrohydraulic shock wave lithotripsy was carried out at rate of 30 shock waves/min for group A versus 60 shock waves/min for group B. In group A, power ramping was from 6 to 18 kV for 100 shock waves, then a safety pause for 2 min, followed by ramping 18-22 kV for 100 shock waves, then a safety pause for 2 min. This full power (22 kV) was maintained until the end of the session. In group B, power ramping was carried out with an increase of 4 kV each 500 shock waves, then maintained on 22 kV in the last 1000-1500 shock waves. Follow up was carried out up to 3 months after the last session. Perioperative data were compared, including the stone free rate (as a primary outcome) and complications (secondary outcome). Predicting factors for success were analyzed using logistic regression.

RESULTS

A total of 100 patients in group A and 96 patients in group B were included. The stone-free rate was significantly higher in group A (76% vs 38.5%; P < 0.001). Both groups were comparable in complication rates (20% vs 19.8%; P = 0.971). The stone-free rate remained significantly higher in group A in logistic regression analysis (odds ratio 24.011, 95% confidence interval 8.29-69.54; P < 0.001).

CONCLUSIONS

Ultraslow full-power shock wave lithotripsy for high attenuation value stones is associated with an improved stone-free rate without affecting safety. Further validation studies are required using other shock wave lithotripsy machines.

The protective effect of low-energy shock wave on testicular ischemia-reperfusion injury is mediated by the PI3K/AKT/NRF2 pathway

AIMS

Testicular ischemia-reperfusion (IR) injury is the primary pathophysiological consequence of testicular torsion. Low-energy shock wave (LESW) is an effective treatment for certain diseases. The present study investigated whether LESW could improve on testicular IR injury in rats and examined the involved mechanism.

MAIN METHODS

Testicular reperfusion was induced in rats after 1-h ischemia. The first LESW treatment was performed 30 min prior to testicular reperfusion, and then every other day for another 3 applications. LY294002 was applied to investigate the involved mechanism. Testicular morphological changes and malonaldehyde (MDA) level were respectively assessed by hematoxylin-eosin staining. Western blot and thiobarbituric acid method. Western blot, real-time quantitative PCR and immunohistochemistry were performed to assess the apoptosis, the activation of phosphatidylinositol-4,5-bisphosphate 3-kinase/protein kinase B (PI3K/AKT) pathway the nuclear factor erythroid 2-related factor 2 (NRF2) and vascular endothelial growth factor A (VEGF-A) level in the testis of rats.

KEY FINDINGS

LESW improved testicular IR injury in rats. Moreover, LESW upregulated the phosphorylation levels of AKT and glycogen synthase kinase 3β (GSK-3β). Also, it upregulated the levels of nuclear NRF2, heme oxygenase 1 (HO-1) and NAD(P)H quinone dehydrogenase 1 (NQO-1) in these rats. Nevertheless, LY294002 blocked these protective effects. LESW also upregulated VEGF-A level in rats with testicular IR injury.

SIGNIFICANCE

This study demonstrated that LESW could ameliorate testicular IR injury in rats, which might be attributed to the activation of PI3K/AKT/NRF2 pathway. These findings suggested the potential of LESW in the treatment of testicular torsion.

Evaluation and physiopathology of minor transient shock wave lithotripsy - induced renal injury based on urinary biomarkers levels

Introduction

Extracorporeal shock wave lithotripsy (ESWL) is one of the most useful methods available for the treatment of urolithiasis. However, despite its significant benefits, adverse effects can occur. Oxidative stress mediated by ischemia-reperfusion might contribute to kidney injury after ESWL. Moreover, an acute kidney injury (AKI) may develop. AKI is typically diagnosed by measuring serum creatinine level, yet serum creatinine does not allow for early detection of sub-clinical AKI. The latest report has investigated multiple ways to determine ESWL - induced renal damage through the evaluation of various urine biomarkers of renal injury.

Materials and methods

The Medline and Web of Science databases were searched without a time limit in November 2017 using the terms 'ESWL' in conjunction with 'kidney failure', 'kidney damage', 'renal injury' and 'inflammation markers', 'biomarkers'. Boolean operators (NOT, AND, OR) were also used in succession to narrow and broaden the search. In this review, we described all the up-to-date reported urine markers of ESWL-induced renal damage.

Results

In recent years, several studies demonstrated evaluation of ESWL - induced renal injury based on urinary biomarkers levels and its utility in clinical practice. They have a beneficial role in the early detection of AKI, as well as in observation of a transition of this acute illness into chronic kidney disease.

Conclusions

Different markers have been evaluated in the urine before and after the ESWL treatment, but their number is still limited and results remain inconclusive. Further investigations are mandatory.

Low-energy shock wave preconditioning reduces renal ischemic reperfusion injury caused by renal artery occlusion

Purpose:

To evaluate whether low energy shock wave preconditioning could reduce renal ischemic reperfusion injury caused by renal artery occlusion.

Methods:

The right kidneys of 64 male Sprague Dawley rats were removed to establish an isolated kidney model. The rats were then divided into four treatment groups: Group 1 was the sham treatment group; Group 2, received only low-energy (12 kv, 1 Hz, 200 times) shock wave preconditioning; Group 3 received the same low-energy shock wave preconditioning as Group 2, and then the left renal artery was occluded for 45 minutes; and Group 4 had the left renal artery occluded for 45 minutes. At 24 hours and one-week time points after reperfusion, serum inducible nitric oxide synthase (iNOS), neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), creatinine (Cr), and cystatin C (Cys C) levels were measured, malondialdehyde (MDA) in kidney tissue was detected, and changes in nephric morphology were evaluated by light and electron microscopy.

Results:

Twenty-four hours after reperfusion, serum iNOS, NGAL, Cr, Cys C, and MDA levels in Group 3 were significantly lower than those in Group 4; light and electron microscopy showed that the renal tissue injury in Group 3 was significantly lighter than that in Group 4. One week after reperfusion, serum NGAL, KIM-1, and Cys C levels in Group 3 were significantly lower than those in Group 4.

Conclusion:

Low-energy shock wave preconditioning can reduce renal ischemic reperfusion injury caused by renal artery occlusion in an isolated kidney rat model.

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.

HMGB1/TLR4 signaling induces an inflammatory response following high-pressure renal pelvic perfusion in a porcine model

Percutaneous nephrolithotomy (PCNL) causes a rapid increase in renal pelvic pressure in the kidney, which induces an inflammatory response. High-mobility group box-1 (HMGB1) is known to trigger the recruitment of inflammatory cells and the release of proinflammatory cytokines following ischemia reperfusion injury in the kidney, but the contribution of HMGB1 to the inflammatory response following high-pressure renal pelvic perfusion has not been investigated. In this study, high-pressure renal pelvic perfusion was induced in anesthetized pigs to examine the effect of HMGB1 on the inflammatory response. HMGB1 levels in the kidney increased following high-pressure renal pelvic perfusion, together with elevated levels of inflammatory cytokines in the plasma and kidney and an accumulation of neutrophils and macrophages. Inhibition of HMGB1 alleviated this inflammatory response while perfusion with recombinant HMGB1 had an augmentative effect, confirming the involvement of HMGB1 in the inflammatory response to high-pressure renal pelvic perfusion. HMGB1 regulated the inflammatory response by activating Toll-like receptor 4 (TLR4) signaling. In conclusion, this study has demonstrated that HMGB1/TLR4 signaling contributes to the inflammatory response following high-pressure renal pelvic perfusion in a porcine model and has implications for the management of inflammation after PCNL.

Using 300 Pretreatment Shock Waves in a Voltage Ramping Protocol Can Significantly Reduce Tissue Injury During Extracorporeal Shock Wave Lithotripsy

PURPOSE

Pretreating a pig kidney with 500 low-energy shock waves (SWs) before delivering a clinical dose of SWs (2000 SWs, 24 kV, 120 SWs/min) has been shown to significantly reduce the size of the hemorrhagic lesion produced in that treated kidney, compared with a protocol without pretreatment. However, since the time available for patient care is limited, we wanted to determine if fewer pretreatment SWs could be used in this protocol. As such, we tested if pretreating with 300 SWs can initiate the same reduction in renal lesion size as has been observed with 500 SWs.

MATERIALS AND METHODS

Fifteen female farm pigs were placed in an unmodified Dornier HM-3 lithotripter, where the left kidney of each animal was targeted for lithotripsy treatment. The kidneys received 300 SWs at 12 kV (120 SWs/min) followed immediately by 2000 SWs at 24 kV (120 SWs/min) focused on the lower pole. These kidneys were compared with kidneys given a clinical dose of SWs with 500 SW pretreatment, and without pretreatment. Renal function was measured both before and after SW exposure, and lesion size analysis was performed to assess the volume of hemorrhagic tissue injury (% functional renal volume, FRV) created by the 300 SW pretreatment regimen.

RESULTS

Glomerular filtration rate fell significantly in the 300 SW pretreatment group by 1 hour after lithotripsy treatment. For most animals, low-energy pretreatment with 300 SWs significantly reduced the size of the hemorrhagic injury (to 0.8% ± 0.4%FRV) compared with the injury produced by a typical clinical dose of SWs.

CONCLUSIONS

The results suggest that 300 pretreatment SWs in a voltage ramping treatment regimen can initiate a protective response in the majority of treated kidneys and significantly reduce tissue injury in our model of lithotripsy injury.

Review on Lithotripsy and Cavitation in Urinary Stone Therapy

Cavitation is the sudden formation of vapor bubbles or voids in liquid media and occurs after rapid changes in pressure as a consequence of mechanical forces. It is mostly an undesirable phenomenon. Although the elimination of cavitation is a major topic in the study of fluid dynamics, its destructive nature could be exploited for therapeutic applications. Ultrasonic and hydrodynamic sources are two main origins for generating cavitation. The purpose of this review is to give the reader a general idea about the formation of cavitation phenomenon and existing biomedical applications of ultrasonic and hydrodynamic cavitation. Because of the high number of the studies on ultrasound cavitation in the literature, the main focus of this review is placed on the lithotripsy techniques, which have been widely used for the treatment of urinary stones. Accordingly, cavitation phenomenon and its basic concepts are presented in Section II. The significance of the ultrasound cavitation in the urinary stone treatment is discussed in Section III in detail and hydrodynamic cavitation as an important alternative for the ultrasound cavitation is included in Section IV. Finally, side effects of using both ultrasound and hydrodynamic cavitation in biomedical applications are presented in Section V.

Shock wave induces biological renal damage by activating excessive inflammatory responses in rat model

The study was aimed to investigate the potential mechanism of inflammatory renal damage induced by shock wave. A total of 48 rats, with the right kidney cut, are randomly assigned into control group, ESWL group and ESWL + PDTC group. Rats were treated with shock wave at the left kidney. At post-shock wave 3 and 105 days, all the animals were sacrificed for detecting the expression of tumor necrosis factor (TNF)-α, intercellular adhesion molecule (ICAM)-1, and monocyte chemoattractant protein (MCP)-1. The inflammatory responses were evaluated by detecting the level of myeloperoxidase (MPO) and ED-1. The histological renal injury was also examined. Before the animals were sacrificed, the urine samples were collected for measuring the values of malondialdehyde (MDA), β2-microglobulin, interleukin (IL)-6, and IL-18. At post-shock wave 3 days, the higher expression of ICAM-1 and TNF-α were observed in shock wave-treated kidneys. The level of urine TNF-α, IL-6, and IL-18 were also increased significantly. Using PDTC obviously decreased the expression of ICAM-1 and TNF-α. It also effectively inhibited the degree of oxidative stress and neutrophil infiltration. At post-shock wave 105 days, the expression of MCP-1 and the level of urine β2-microglobulin and IL-18 were increased significantly. The histological analysis also indicated more ED-1-positive cells and serious fibrosis in shock wave-treated kidneys. PDTC significantly suppressed MCP-1 and IL-18 expression, decreased monocyte infiltration, and alleviate the degree of interstitium fibrosis. Shock wave triggered excessive inflammatory responses and aggravated renal biological damage. Several inflammatory factors including ICAM-1, MCP-1, and TNF-α were considered to play important role in this type of renal damage.

Low-intensity shock wave therapy and its application to erectile dysfunction

Although phosphodiesterase type 5 inhibitors (PDE5Is) are a revolution in the treatment of erectile dysfunction (ED) and have been marketed since 1998, they cannot restore pathological changes in the penis. Low-energy shock wave therapy (LESWT) has been developed for treating ED, and clinical studies have shown that LESWT has the potential to affect PDE5I non-responders with ED with few adverse effects. Animal studies have shown that LESWT significantly improves penile hemodynamics and restores pathological changes in the penis of diabetic ED animal models. Although the mechanisms remain to be investigated, recent studies have reported that LESWT could partially restore corpus cavernosum fibromuscular pathological changes, endothelial dysfunction, and peripheral neuropathy. LESWT could be a novel modality for treating ED, and particularly PDE5I non-responders with organic ED, in the near future. However, further extensive evidence-based basic and clinical studies are needed. This review intends to summarize the scientific background underlying the effect of LESWT on ED.

Is there a difference in percutaneous nephrolithotomy outcomes among various types of pelvicaliceal system?

PURPOSE

During PNL procedures, stone clearance can be achieved by single access or multiple accesses for same stone size and configuration. At this point, we believed that pelvicaliceal system type may play a significant role on stone clearance. In our study, we aimed to investigate the effect of pelvicaliceal system type on PNL outcomes.

METHODS

A total of 498 patients who had preoperative intravenous urography were enrolled in our study. PCSs of the patients were classified as A1, A2, B1, and B2 according to Sampaio system after evaluation of IVU images. The exclusion criteria were unclassified pelvicaliceal system due to the presence of exaggerated renal hydronephrosis, IVUs with poor quality, radiolucent renal stones, and absence of CT or IVU in postoperative period.

RESULTS

There was no clinically significant difference for patient gender, history of open surgery, and history of previous SWL. Success rates of PNL were 79.5, 82.0, 74.3, and 80.3 % in Sampaio type A1, A2, B1, and B2 PCS, respectively (p 0.61). Multiple accesses were required for 35 (18.8 %), 14 (17.9 %), 55 (30.1 %), and 6 (11.8 %) patients according to Sampaio classification type A1, A2, B1, and B2, respectively (p 0.008). There was no clinically significant difference for stone size, stone configuration (simple or complex), and complications.

CONCLUSION

Sampaio type B1 PCSs require increased number of access for achieving stone clearance. Therefore, surgeons should be aware and also inform patients that treatment of patients with Sampaio type B1 PCS may need high number of access during PNL procedure.