Relationship between kidney size, renal injury, and renal impairment induced by shock wave lithotripsy.

The relationship between kidney size and impaired renal function induced by shock-wave lithotripsy (SWL) was examined in 6- and 10-wk-old anesthetized pigs. Each pig received 2000 shock waves, 24 kV, or sham SWL to the lower pole calyx of one kidney. Bilateral GFR, renal plasma flow (RPF), and para-aminohippurate extraction was measured 1 h before and 1 and 4 h after SWL. The kidneys were then removed for morphometric analysis. Mean kidney weights were 66.1+/-2.7 g (n = 9) and 103.1+/-3.3 g (n = 8) in the SWL groups, and 60.1+/-2.6 g (n = 9) and 82.3+/-4.0 g (n = 9) in the sham-SWL groups. SWL-induced lesions occupied a significantly greater volume of the small kidneys (6.1+/-1.7 vol % versus 1.5+/-0.2 vol% in the large kidneys). RPF was significantly reduced by SWL in small and large kidneys, but to a significantly greater extent in small kidneys. RPF was also significantly reduced in the contralateral kidneys of both groups, but only at 1 h after SWL. SWL significantly reduced GFR to similar degrees in both kidneys of both groups, regardless of kidney size. Para-aminohippurate extraction was likewise reduced to similar degrees in both groups, but this effect was evident only in the SWL-treated kidneys, and only in the pole to which the shock waves had been applied. The injury induced by SWL affected a larger fraction of small kidneys than large ones, and the renal vasoconstriction induced by SWL was greatest in small kidneys.     

Renal disease potentiates the injury caused by SWL

PURPOSE: The present study tested the hypothesis that renal disease potentiates the structural/functional changes induced by a clinical dose of shockwaves. MATERIALS AND METHODS: Experimental pyelonephritis was induced in 6- to 8-week-old pigs before treatment with 2,000 shocks at 24 kV. These pigs were divided into two groups according to whether they were infected with a highly virulent (Group 1) or less virulent (Group 2) inoculation of E. coli. All animals were imaged by MR prior to SWL as a means of documenting the extent of pyelonephritis and immediately after SWL to examine the lesion produced by the shockwaves. The glomerular filtration rate (GFR), renal plasma flow (RPF) and para-aminohippurate (PAH) extraction were determined bilaterally on day 30 (Group 1) or day 80 (Group 2). RESULTS: In group 2, urine flow and sodium excretion were reduced by 50% from baseline in the shocked kidneys at both 1 and 4 hours post-SWL. A sustained reduction in RPF through 4 hours post-SWL was noted in the shocked kidneys in Group 1, but RPF was significantly reduced only at the 1-hour determination in Group 2. Large, consistent reductions in GFR were evident at 1 and 4 hours post-SWL in shocked and unshocked kidneys of Group 2 and in the shocked kidneys of Group 1. No significant changes were noted in PAH extraction. CONCLUSION: Acute pyelonephritis exaggerated the effect of a clinical dose of shockwaves on renal hemodynamics. This effect suggests that renal disease may be risk factor for SWL-induced injury.     

Shockwave lithotripsy: dose-related effects on renal structure, hemodynamics, and tubular function

BACKGROUND AND PURPOSE: Shockwave lithotripsy (SWL) predictably damages renal tissue and transiently reduces function in both kidneys. This study characterized the effects on renal function of a supraclinical dose of shockwaves (SWs) (8000) in porcine kidneys and tested the hypothesis that such excessive treatment would intensify and prolong the resulting renal impairment. MATERIALS AND METHODS: Pigs aged 6 to 7 weeks were anesthetized and assigned to one of three groups. Groups 1 (N=8) and 2 (N=6) each received 8000 SWs at 24 kV (Dornier HM3) to the lower-pole calix of one kidney. Group 3 (7 pigs) received sham treatment. Renal function was monitored for the first 4 hours after SW treatment in Group 1 and for 24 hours in Group 2. Plasma renin activity was measured in Groups 2 and 3. RESULTS: The renal lesions produced by 8000 SWs comprised 13.8%+/-1.4% of the renal mass. In the 4-hour protocol, this injury was associated with marked reduction of the glomerular filtration rate (GFR), renal plasma flow (RPF), and urinary sodium excretion in both kidneys, although fractional sodium excretion was reduced only in the shocked kidneys. In the 24-hour protocol, GFR and RPF remained below baseline in shocked kidneys at 24 hours. Evidence of progressive ischemic injury was noted in shocked tissue at 24 hours after SW treatment. CONCLUSIONS: These findings support the hypothesis that the severity of the renal injury caused by SWL is related to the number of SWs administered and demonstrate the connection in this relation between renal structure and function.     

Effects of Extracorporeal Shock Wave Lithotripsy to One Kidney on Bilateral Glomerular Filtration Rate and PAH Clearance in Minipigs

Purpose

This study examined the acute time course of effects of extracorporeal shock wave lithotripsy (ESWL)¹ on renal hemodynamics in anesthetized minipigs with and without pretreatment with verapamil.

Materials and Methods

We applied ESWL (2000 shocks, 24 kV, unmodified Dornier HM3), to the right kidneys of isoflurane-anesthetized female pigs. Urine flow and renal hemodynamics were monitored from each kidney via ureteral balloon catheters. Arterial blood pressure and bilateral urine flow, glomerular filtration rate (GFR, inulin clearance) and renal plasma flow (RPF, para-aminohippurate clearance) were monitored for 45 minutes before ESWL, and at 1, 4 and 24 hours after ESWL.

Results

Treatment with ESWL consistently caused unilateral hematuria and subcapsular renal hematomas in the shocked kidneys and significantly reduced GFR and RPF in those kidneys at 1 and 4 hours after ESWL. Urine flow was reduced through 24 hours in the shocked kidneys. Renal plasma flow, but not GFR, was significantly reduced in the contralateral (unshocked) kidneys at 1 and 4 hours after ESWL to the other kidneys. Verapamil blunted the ESWL-induced reductions of urine flow, GFR and RPF in the shocked kidneys and eliminated the reduction of RPF in the unshocked kidneys.

Conclusions

These experiments demonstrate that ESWL to 1 kidney acutely impaired hemodynamics in both kidneys and that verapamil attenuated the response in the shocked kidneys and eliminated it in the contralateral unshocked kidneys.     

体外冲击波碎石与输尿管软镜治疗肾结石对肾功能影响的研究

目的 探索体外冲击波碎石(SWL)与输尿管软镜治疗(RIRS)肾结石对肾功能的影响.方法 收集2014年6月至2015年6月来本院就诊的符合入选标准的肾结石病例70例,结石最大直径1.0～1.5 cm;随机分组,一组行SWL(35例),另一组行RIRS(35例),留取术前、术后2、6、12、24 h、1周、2周的尿液标本,测定NGAL的变化.结果 肾结石SWL和RIRS术后2、6、12、24h尿液NGAL浓度与术前比较均有不同程度升高(P＜0.05),其中,术后12 h尿液NGAL水平高于其他各时间点,呈峰值状态(P＜0.05),术后24h逐渐下降.其中术后一周μNGAL浓度与术前比较仍有显著性差异[(5.96±1.5) μg/L和(4.84±0.9) μg/L,P=0.0025],至术后2周基本降至术前水平[(5.01±0.8)μg/L和(4.84±0.9).μg/L,P=0.346].而RIRS术后一周尿液NGAL浓度与术前比较已无差异[(5.05±0.8) μg/1和(4.84±0.9)μg/L,P =0.445];肾结石SWL后6、12、24、48 h,一周与RIRS比较尿液NGAL均有不同程度升高,且有显著性差异(P＜0.05).结论 ESWL和RIRS治疗肾结石均引起早期急性肾损伤,并且随着时间呈现出一定的规律.相比较而言,RIRS较ESWL早期的肾损伤更小,且恢复时间快.     

Erratum to: Preventive effects of COX-2 inhibitor, celecoxib on renal tubular injury induced by shock wave lithotriptor

Our study was designed to investigate the protective effect of the COX-2 inhibitor, celecoxib, on renal tubules against shock wave lithotripsy (SWL). Sprague–Dawley rats were randomly divided into three groups: sham, control, and COX-2 groups. The control group was administrated normal saline. The COX-2 group was administered celecoxib (10 mg/kg). After administration for 1 week, the control and COX-2 groups received 1,000 shock waves. Before and after SWL, 24-h urine was collected. CCr was measured to assess renal function. To determine the renal tubular injury, N-acetyl glucosaminidase (NAG) and β-2 microglobulin levels in urine were quantified. The COX-2 gene expression was compared between the three groups. Prior to SWL, all groups had similar levels of NAG and β-2 microglobulin. After SWL, all groups showed similar CCr. Compared with the sham group, control and COX-2 groups produced increase of NAG and β-2 microglobulin excretion. However, NAG and β-2 microglobulin excretions were significantly lower in the COX-2 group than control group. The COX-2 gene expression did not increase in the sham group. However, the COX-2 gene expression was significantly increased in the control group, which was prevented by celecoxib in COX-2 group. Biochemical findings supported a renal protective effect of celecoxib on SWL. This study suggests that celecoxib would be useful prior and after SWL because of renal protective effects.     

Preventive effects of COX-2 inhibitor, celecoxib on renal tubular injury induced by shock wave lithotriptor

Our study was designed to investigate the protective effect of the COX-2 inhibitor, celecoxib, on renal tubules against shock wave lithotripsy (SWL). Sprague–Dawley rats were randomly divided into three groups: sham, control, and COX-2 groups. The control group was administrated normal saline. The COX-2 group was administered celecoxib (10 mg/kg). After administration for 1 week, the control and COX-2 groups received 1,000 shock waves. Before and after SWL, 24-h urine was collected. CCr was measured to assess renal function. To determine the renal tubular injury, N-acetyl glucosaminidase (NAG) and β-2 microglobulin levels in urine were quantified. The COX-2 gene expression was compared between the three groups. Prior to SWL, all groups had similar levels of NAG and β-2 microglobulin. After SWL, all groups showed similar CCr. Compared with the sham group, control and COX-2 groups produced increase of NAG and β-2 microglobulin excretion. However, NAG and β-2 microglobulin excretions were significantly lower in the COX-2 group than control group. The COX-2 gene expression did not increase in the sham group. However, the COX-2 gene expression was significantly increased in the control group, which was prevented by celecoxib in COX-2 group. Biochemical findings supported a renal protective effect of celecoxib on SWL. This study suggests that celecoxib would be useful prior and after SWL because of renal protective effects.     

Effect of initial shock wave voltage on shock wave lithotripsy-induced lesion size during step-wise voltage ramping

OBJECTIVE

To determine if the starting voltage in a step‐wise ramping protocol for extracorporeal shock wave lithotripsy (SWL) alters the size of the renal lesion caused by the SWs.

MATERIALS AND METHODS

To address this question, one kidney from 19 juvenile pigs (aged 7–8 weeks) was treated in an unmodified Dornier HM‐3 lithotripter (Dornier Medical Systems, Kennesaw, GA, USA) with either 2000 SWs at 24 kV (standard clinical treatment, 120 SWs/min), 100 SWs at 18 kV followed by 2000 SWs at 24 kV or 100 SWs at 24 kV followed by 2000 SWs at 24 kV. The latter protocols included a 3–4 min interval, between the 100 SWs and the 2000 SWs, used to check the targeting of the focal zone. The kidneys were removed at the end of the experiment so that lesion size could be determined by sectioning the entire kidney and quantifying the amount of haemorrhage in each slice. The average parenchymal lesion for each pig was then determined and a group mean was calculated.

RESULTS

Kidneys that received the standard clinical treatment had a mean (sem ) lesion size of 3.93 (1.29)% functional renal volume (FRV). The mean lesion size for the 18 kV ramping group was 0.09 (0.01)% FRV, while lesion size for the 24 kV ramping group was 0.51 (0.14)% FRV. The lesion size for both of these groups was significantly smaller than the lesion size in the standard clinical treatment group.

CONCLUSIONS

The data suggest that initial voltage in a voltage‐ramping protocol does not correlate with renal damage. While voltage ramping does reduce injury when compared with SWL with no voltage ramping, starting at low or high voltage produces lesions of the same approximate size. Our findings also suggest that the interval between the initial shocks and the clinical dose of SWs, in our one‐step ramping protocol, is important for protecting the kidney against injury.     

Pretreatment with low‐energy shock waves induces renal vasoconstriction during standard shock wave lithotripsy (SWL): a treatment protocol known to reduce SWL‐induced renal injury

OBJECTIVE

To test the hypothesis that the pretreatment of the kidney with low‐energy shock waves (SWs) will induce renal vasoconstriction sooner than a standard clinical dose of high‐energy SWs, thus providing a potential mechanism by which the pretreatment SW lithotripsy (SWL) protocol reduces tissue injury.

MATERIALS AND METHODS

Female farm pigs (6‐weeks‐old) were anaesthetized with isoflurane and the lower pole of the right kidney treated with SWs using a conventional electrohydraulic lithotripter (HM3, Dornier GmbH, Germany). Pulsed Doppler ultrasonography was used to measure renal resistive index (RI) in blood vessels as a measure of resistance/impedance to blood flow. RI was recorded from one intralobar artery located in the targeted pole of the kidney, and measurements taken from pigs given sham SW treatment (Group 1; no SWs, four pigs), a standard clinical dose of high‐energy SWs (Group 2; 2000 SWs, 24 kV, 120 SWs/min, seven pigs), low‐energy SW pretreatment followed by high‐energy SWL (Group 3; 500 SWs, 12 kV, 120 SWs/min + 2000 SWs, 24 kV, 120 SWs/min, eight pigs) and low‐energy SW pretreatment alone (Group 4; 500 SWs, 12 kV, 120 SWs/min, six pigs).

RESULTS

Baseline RI (≈0.61) was similar for all groups. Pigs receiving sham SW treatment (Group 1) had no significant change in RI. A standard clinical dose of high‐energy SWs (Group 2) did not significantly alter RI during treatment, but did increase RI at 45 min after SWL. Low‐energy SWs did not alter RI in Group 3 pigs, but subsequent treatment with a standard clinical dose of high‐energy SWs resulted in a significantly earlier (at 1000 SWs) and greater (two‐fold) rise in RI than that in Group 2 pigs. This rise in RI during the low/high‐energy SWL protocol was not due to a delayed vasoconstrictor response of pretreatment, as low‐energy SW treatment alone (Group 4) did not increase RI until 65 min after SWL.

CONCLUSIONS

The pretreatment protocol induces renal vasoconstriction during the period of SW application whereas the standard protocol shows vasoconstriction occurring after SWL. Thus, the earlier and greater rise in RI during the pretreatment protocol may be causally associated with a reduction in tissue injury.     

Damaging effects of high energy shock waves on cultured Madin Darby Canine Kidney (MDCK) cells

Summary Shock wave lithotripsy (ESWL) has become an almost non-invasive standard treatment modality for urolithiasis. Several investigations, however, demonstrated that ESWL is not completely free of side effects. Among others alteration of renal tubular function has been reported. To study the effect of shock waves on tubular cells directly an in-vitro model with cultured Madin Darby Canine Kidney (MDCK) cells was established. Suspensions of MDCK cells (7 groups of 6 containers each) were exposed to 0, 16, 32, 64, 128, 256 shock waves (Dornier HM4, 18 kV). Before and 0, 1, 3, 6, 9, 12, 24 h after ESWL the following parameters were measured in the nutrient medium: lactate dehydroxygenase (LDH), glutamate oxalacetate transaminase (GOT), electrolytes. LDH and GOT increased depending on the number of shock waves indicating a membrane damage of MDCK cells. The MDCK model seems suitable for further studies on the effect of shock waves on renal tubular cells.     

Shockwave lithotripsy and protective role of inosine: early and late evaluation in an experimental model

PURPOSE: Extracorporeal shockwave lithotripsy (SWL) is one of the most common treatments for urinary stones. Despite technological improvements, it may cause side effects varying from minor reversible microscopic damage to severe large renal hematomas. The aim of our experimental study is to assess the efficacy of inosine in avoidance of acute renal damage after SWL. MATERIALS AND METHODS: We used 25 Wistar rats that had previously had left nephrectomy. The rats were divided into three groups: group A consisted of 10 rats undergoing renal SWL; group B consisted of 10 rats that received adjunctive treatment with IP injection of inosine 40 minutes before SWL; and group C consisted of 5 rats that served as controls. N-acetylglucosaminidase (NAG) and lactate dehydrogenase (LDH) concentrations were evaluated 24 hours before and 24 hours after SWL. All the rats were subsequently sacrificed (4 rats in group A and 4 in group B at 48 hours post-SWL, and the remaining rats were sacrificed 30 days post-SWL). Renal tissue was submitted to histologic and electron microscopic examination to assess early and late alterations. RESULTS: NAG and LDH values were significantly increased after SWL in group A (P<0.001), while no significant NAG and LDH differences were detected in group B (P<0.16). Early histologic examination revealed a considerable amount of cellular degeneration in group A with ultrastructural vacuolization and disruption of lysosomal membranes; the tubular features and cellular structures appeared to be well preserved in group B. No late histologic alterations were evident in any of the specimens. CONCLUSIONS: Inosine is helpful and protective in the prevention of early microscopic damage to renal parenchyma due to SWL.     

Effect of shock wave number on renal oxidative stress and inflammation

What’s known on the subject? and What does the study add? Oxidative stress and inflammation are tissue‐ and cell‐level components of shock wave lithotripsy (SWL)‐induced acute renal injury, which we recently showed to be localized principally to the medulla within the focal zone of the lithotripter. This study reports that the magnitude of the oxidative stress and inflammation observed in the medulla after SWL is dependent on the number of shock waves delivered to the kidney, indicating that this is a sensitive measure of renal injury caused by shock waves. OBJECTIVE To determine if the magnitude of the acute injury response to shock‐wave lithotripsy (SWL) depends on the number of SWs delivered to the kidney, as SWL causes acute renal oxidative stress and inflammation which are most severe in the portion of the kidney within the focal zone of the lithotripter. MATERIALS AND METHODS Pigs (7–8 weeks old) received 500, 1000 or 2000 SWs at 24 kV from a lithotripter to the lower pole calyx of one kidney. At 4 h after treatment the kidneys were removed, and samples of cortex and medulla were frozen for analysis of the cytokine, interleukin‐6, and for the stress response protein, heme oxygenase‐1 (HO‐1). Urine samples taken before and after treatment were analysed for the inflammatory cytokine, tumour necrosis factor‐α. For comparison, we included previously published cytokine data from pigs exposed to sham treatment. RESULTS Treatment with either 1000 or 2000 SWs caused a significant induction of HO‐1 in the renal medulla within the focal zone of the lithotripter (F2, 1000 SWs, P < 0.05; 2000 SWs, P < 0.001). Interleukin‐6 was also significantly elevated in the renal medulla of the pigs that received either 1000 or 2000 SWs (P < 0.05 and <0.001, respectively). Linear dose–response modelling showed a significant correlation between the HO‐1 and interleukin‐6 responses with SW dose (P < 0.001). Urinary excretion of tumour necrosis factor‐α from the lithotripsy‐treated kidney increased only for pigs that received 2000 SWs (P < 0.05). CONCLUSION The magnitude of renal oxidative stress and inflammatory response in the medulla increased with the number of SWs. However, it is not known if the HO‐1 response is beneficial or deleterious; determining that will inform us whether SWL‐induced renal injury can be assessed by quantifying markers of oxidative stress and inflammation.     

肾脂肪囊内注射黄芪和多巴胺对大鼠内毒素休克所致急性肾衰竭的防治作用

目的:探讨肾脂肪囊内联合应用黄芪和多巴胺对大鼠内毒素休克所致急性肾衰竭的防治作用及其机制.方法:SD大鼠随机分为对照组、内毒素组、静脉应用与肾脂肪囊内应用黄芪和多巴胺组,分别测定平均动脉压(MAp)、肾血浆流量(RPF)、肾小球滤过率(GFR)、尿量(UO)、滤过钠排泄分数(FENa)以及肾组织一氧化氮(NO)和内皮素(ET)浓度,光镜及电镜观察病理改变.结果:内毒素组MAp和RPF、GFR、UO显著降低,FENa初4 h极度减少,随后增高,至12 h后接近或大于2%,肾组织NO和ET浓度明显升高;黄芪和多巴胺联合应用可稳定MAp,提高RPF和GFR,增加UO,改善FENa,降低肾组织NO和ET水平,减轻组织病理损害,尤以肾脂肪囊内给药组肾脏保护效果显著,实验后期作用更为明显.结论:黄芪和多巴胺联合应用可纠正大鼠内毒素休克低血压状态,改善肾脏功能,减轻病理损害,可能与作用于NO和ET系统有关.     

Is intravenous urography a prerequisite for renal shockwave lithotripsy?

PURPOSE: To determine whether intravenous urography (IVU) is a prerequisite for shockwave lithotripsy (SWL) of renal stones by addressing whether using non-contrast-enhanced CT (NCCT) instead of IVU for delineating urinary tract anatomy is associated with post-SWL complications. PATIENTS AND METHODS: Thirty-eight patients treated by SWL (Econolith 2000) for radiopaque renal stones underwent either IVU or NCCT. Twenty patients with normal urinary tracts or with mild hydronephrosis proximal to the stone on urography comprised the IVU group. Eighteen patients who underwent NCCT and plain abdominal (KUB) films and had urinary tract systems similar in appearance to the IVU group comprised the NCCT group. The two groups were of similar mean age (45.75 years, range 24-73 years; and 49.0 years, range 26-72 years, respectively) and had a similar mean stone size (10.1-10.2 mm). Patients with internal ureteral or nephrostomy catheters were excluded. Information on episodes of intractable renal colic, urinary tract infections, and hospitalization was recorded at follow-up 2 to 6 weeks post-SWL. RESULTS: The IVU and NCCT patients had similar mean stone fragmentation rates (80% and 74%, respectively) at 2 to 6 weeks post-SWL. Four IVU patients (20%) had intractable renal colic. One NCCT patient (5.5%) had a urinary infection. Complication and hospitalization rates in the two groups were not significantly different (P = 0.34; Fisher' exact test). CONCLUSIONS: Using only NCCT before SWL was not associated with higher complication rates. Thus, IVU is not a prerequisite for SWL of radiopaque renal stones in patients with a normal urinary tract anatomy as seen on NCCT.     

Extracorporeal shock wave lithotripsy at 60 shock waves/min reduces renal injury in a porcine model

OBJECTIVE

To determine if extracorporeal shock wave lithotripsy (ESWL) at 60 shock waves (SWs)/min reduces renal damage and haemodynamic impairment compared to treatment at 120 SWs/min.

MATERIALS AND METHODS

One kidney in each of 19 juvenile pigs (7–8 weeks old) was treated at 120 or at 60 SWs/min (2000 SWs, 24 kV) with an unmodified HM‐3 lithotripter (Dornier Medical Systems, Kennesaw, GA, USA). Renal function was determined before and after ESWL treatment by inulin clearance, extraction and clearance of para‐aminohippuric acid. Both kidneys were then removed to measure parenchymal lesion size by sectioning the entire kidney and quantifying the size of the haemorrhagic lesion in each slice.

RESULTS

ESWL at 60 SWs/min significantly reduced the size of the acute morphological lesion compared to 120 SWs/min (0.42% vs 3.93% of functional renal volume, P = 0.011) and blunted the decrease in glomerular filtration rate and renal plasma flow normally seen after treatment at 120 SWs/min.

CONCLUSIONS

Treatment at a firing rate of 60 SWs/min produces less morphological injury and causes less alteration in renal haemodynamics than treatment at 120 SWs/min in the pig model of ESWL‐induced renal injury.     

Hepatic haematoma after shockwave lithotripsy for renal stones

Extracorporeal shock wave lithotripsy (SWL) is a non-invasive procedure for urolithiasis. Only a very small portion of patients suffer from post-SWL haematoma and most of them have perinephric haematoma formation. We present two patients who developed subcapsular hepatic haematomas after SWL, followed by a review of the literature on the condition.     

Pyrrolidine dithiocarbamate attenuate shock wave induced MDCK cells injury via inhibiting nuclear factor-kappa B activation

Shock wave lithotripsy (SWL)-induced renal damage appears to be multifactorial. Recent data indicated that the mechanism of renal tissue damage secondary to SWL is similar to that of ischemia reperfusion injury. Nuclear factor-kappa B (NFκB) and its target genes, inducible nitric oxide synthase (iNOS) and cyclooxygense-2 (COX-2), have been demonstrated to play a very important role in a variety of cells or tissues ischemia reperfusion injuries. Thus in the present study, using an in vitro model MDCK cells, we investigated the role of NFκB and its target cytotoxic enzyme in shock wave-induced renal cellular damage. We also examined whether inhibition this pathway by pyrrolidine dithiocarbamate (PDTC) is contributed to alleviate SWL-caused cell damage. Suspensions of MDCK cells were placed in containers for shock wave exposure. Three groups of six containers each were examined: control group, no shock wave treatment and SWL group, which received 100 shocks at 18 kV; 3 SWL + PDTC group. PDTC were added to the suspensions before shock wave exposure. After shock wave 0, 2, 4, 6 and 8 h, respectively, the cell supernatants were detected for the level of MDA and release of LDH. At post-shock wave 8 h, cells were harvested to detect the nuclear translocation of NFκBp65 by immunofluorescence staining. Degradation of IκB-а (an inhibitor protein of NFκB) and expression of iNOS and COX-2 were also examined by western blotting. Our results indicated that shock wave initiated the apparent activation of NFκB, which in turn induced high expression of iNOS and COX-2. Blocking degradation of IκB-а by PDTC was contributed to decrease the expression of iNOS. And the level of MDA and the release of LDH were also significantly reduced by using PDTC. However, the degree of COX-2 expression does not differ significantly between SWL and SWL + PDTC groups. Activation of NFκB and subsequent expression of its target cytotoxic enzyme have been demonstrated to be a potential and crucial mechanism in SWL-induced renal cell damage. Blocking this pathway by PDTC is contributed to protect against cellular damage from shock wave.     

Extracorporeal shock wave lithotripsy for ureteral stone in patient with implanted cardiac pacemaker: a case report

We report a case of extracorporeal shock wave lithotripsy (SWL) for ureteral stone in patient with implanted cardiac pacemaker. A 68-year-old woman was admitted to our hospital for left back pain due to left single ureteral stone (13 x 7 mm) in 2002. A permanent cardiac pacemaker has been implanted for sick sinus syndrome in 1997. After evaluation for cardiac function and pacemaker function by a cardiologist and a pacemaker technician, SWL (MFL 5000, Dornier) was performed without changing pacemaker mode (DDD mode). Shock waves were incorrectly exposed a few time triggered by arterial pacing amplitude, but no cardiovascular event or malfunction of the pacemaker was occurred during or after SWL. The ureteral stone was successfully fragmented with 2,400 shock waves (24 kV) and the fragments were delivered immediately.     

The effect of treatment strategy on stone comminution efficiency in shock wave lithotripsy

PURPOSE: The comminution of kidney stones in shock wave lithotripsy (SWL) is a dose dependent process caused primarily by the combination of 2 fundamental mechanisms, namely stress waves and cavitation. The effect of treatment strategy with emphasis on enhancing the effect of stress waves or cavitation on stone comminution in SWL was investigated. Because vascular injury in SWL is also dose dependent, optimization of the treatment strategy may produce improved stone comminution with decreased tissue injury in SWL. MATERIALS AND METHODS: Using an in vitro experiment system that mimics stone fragmentation in the renal pelvis spherical BegoStone (Bego USA, Smithfield, Rhode Island) phantoms (diameter 10 mm) were exposed to 1,500 shocks at a pulse repetition rate of 1 Hz in an unmodified HM-3 lithotripter (Dornier Medical Systems, Kennesaw, Georgia). The 3 treatment strategies used were increasing output voltage from 18 to 20 and then to 22 kV every 500 shocks with emphasis on enhancing the effect of cavitation on medium fragments (2 to 4 mm) at the final treatment stage, decreasing output voltage from 22 to 20 and then to 18 kV every 500 shocks with emphasis on enhancing the effect of stress waves on large fragments (greater than 4 mm) at the initial treatment stage and maintaining a constant output voltage at 20 kV, as typically used in SWL procedures. Following shock wave exposure the size distribution of fragments was determined by the sequential sieving method. In addition, pressure waveforms at lithotripter focus (F2) produced at different output settings were measured using a fiber optic probe hydrophone. RESULTS: The rate of stone comminution in SWL varied significantly in a dose dependent manner depending on the treatment strategies used. Specifically the comminution efficiencies produced by the 3 strategies after the initial 500 shocks were 30.7%, 59% and 41.9%, respectively. After 1,000 shocks the corresponding comminution efficiencies became similar (60.2%, 68.1% and 66.4%, respectively) with no statistically significant differences (p = 0.08). After 1,500 shocks the final comminution efficiency produced by the first strategy was 88.7%, which was better than the corresponding values of 81.2% and 83.5%, respectively, for the other 2 strategies. The difference between the final comminution efficiency of the first and second strategies was statistically significant (p = 0.005). CONCLUSIONS: Progressive increase in lithotripter output voltage can produce the best overall stone comminution in vitro.     

Acute physiological changes in canine kidneys following exposure to extracorporeal shock waves

Nine anesthetized dogs were studied for four to five hours after administration of extracorporeal shock waves to one kidney, the contralateral organ serving as control. Urinary excretion of electrolytes, N-acetyl-beta-glucosaminidase (NAG) and kallikrein, clearances of creatinine, inulin and para-amino-hippuric acid (PAH), serum aldosterone level and plasma renin activity (PRA) were determined. On the exposed side there was a significant increase in urinary flow and urinary NAG excretion, and a significant fall in urinary osmolality. Effective renal plasma flow (ERPF) was reduced and glomerular filtration rate (GFR) unchanged, thus filtration fraction (FF) was increased. Extraction of PAH was significantly reduced compared with the control kidney. On the control side there was a significant increase in urinary flow and excretion of electrolytes, and a significant fall in urinary osmolality. GFR was increased and ERPF unchanged. FF therefore increased also on this side. The mean rise of PRA in the exposed kidney was higher than in the control kidney, the difference being not significant (p = 0.09). Our results may indicate a triggering of the renin-angiotensin system, and an effect on proximal tubular function following exposure of extracorporeal shock waves.