Physical laws of cholesterol gallstone fragmentation

Efficient fragmentation is the most important prerequisite for successful treatment of gallstones by extracorporeally induced shock waves. No data are available on the amount of energy necessary for stone disintegration and on the threshold energy below which no further fragmentation occurs. We therefore performed an in vitro investigation on human cholesterol gallstones to elucidate physical laws governing shock-wave lithotripsy. First, the focal pressure of the lithotripter was measured to calculate the energy traversing a stone. Second, 96 gallstones from 16 gall bladders were analysed with respect to physicochemical composition, radiological features and ultrasound before fragmentation was performed. Energy for stone disintegration was constant within each stone family but varied between 4.6 J mL^?1 and 36.8 J mL^?1 in different families. This energy correlated linearly with stone volume. None of the radiological and physicochemical factors revealed a clear-cut correlation of the different energies necessary for similar stone disintegration. The threshold energy differed between 0.26 mJ and 1.04 mJ per pulse. In conclusion, stone volume was the best parameter predicting stone fragmentation. However, in cholesterol stones with a similar composition the required energy per volume varies considerably together with the threshold energy. Radiological and ultrasound parameters appear to be of minor importance in explaining these differences.     

Three-dimensional assessment of urinary stone on non-contrast helical computed tomography as the predictor of stonestreet formation after extracorporeal shock wave lithotripsy for stones smaller than 20 mm

The incidence of stonestreet formation after extracorporeal shock wave lithotripsy (ESWL) rises with increasing stone burden. However, stonestreet after ESWL is often experienced even in stones smaller than 20 mm. To examine whether the non-contrast helical computed tomography (CT) data could predict stonestreet formation in these stones, 53 radiopaque stones of 5-20 mm treated with ESWL were evaluated. Maximal dimension was measured on plain radiograph. From an attenuation value histogram graphed from the CT data, total stone volume and mean attenuation value were calculated. Seven stonestreets longer than 25 mm developed. There was no significant difference in maximal dimension and total stone volume between stones that did and stones that did not develop stonestreet. Mean attenuation value was the sole significant predictive factor. Application of mean attenuation value with cut-off level of 650 HU would anticipate stonestreet formation with a sensitivity of 85.7% and a specificity of 71.7%. The estimated risk of stonestreet formation is high in the treatment of stones with higher mean attenuation value.     

单用体外震波碎石治疗尿路结石的体会

本文报道1988年6月～11月,单独应用上海交通大学电力工程系研制的JT—ESWL—Ⅱ型体外震波碎石机,治疗尿路结石506例,其中肾结石304例(双侧12例)输尿管结石199例(双侧5例),膀胱结石3例。冲击能量15～40焦耳,每次治疗冲击波次数为400～2800次。本组无开放手术、无肾脏丧失、无死亡。效果满意者96.44％。其并发症主要有血尿、结石串。作者认为单用ESWL治疗小于3Cm的尿路结石安全可靠、无严重并发症。文中对单用体外震波碎石(ESWL)治疗尿路结石病例选择,如何减少并发症,提高治疗效果进行了讨论。     

经皮肾穿气压弹道碎石联合体外冲击波碎石治疗上尿路结石

目的 探讨提高上尿路结石碎石成功率的微创治疗方法。方法 采用经皮肾穿微造瘘输尿管镜气压弹道碎石，术中放置双J管，术后配合体外冲击波碎石术(ESWL)治疗上尿路结石48例。结果 结石总排净率为89．1％，结石最小排净率79．2％，无严重并发症发生。结论 该方法结石排净率高，创伤较小，手术并发症少，是上尿路结石较为理想的微创治疗方法。     

肾盏切开联合经肾实质气压弹道碎石治疗复杂鹿角形结石

目的探讨肾盏切开联合经肾实质气压弹道碎石治疗复杂鹿角形结石的疗效。方法电刀切开积水较重的肾盏,气压弹道碎石杆对准结石碎石后分块取出。盏颈口狭窄但肾盏积水不严重者,将直径1 mm气压弹道碎石杆于肾实质处刺入结石位置,将肾盏内结石击碎后从盏颈口取出。结果19例均未阻断肾蒂,手术时间90-150 min,平均120 min。术中出血量100-250 ml,未输血。17例一次取石成功,术后无结石残余;1例术中残余泥沙状结石,术后经肾造瘘管冲洗引流排出;1例肾盏结石术中取石遗漏,术后经ESWL碎石后排净结石。15例随访10-60个月,平均18个月,结石复发2例,体外震波碎石后排净结石。结论肾盏切开联合经肾实质气压弹道碎石治疗复杂性鹿角形结石出血少,疗效可靠。     

尿石症住院患者1100例分析

目的了解近年来尿石症住院患者情况的变化。方法对1998年~2003年间的尿石症住院患者1100例进行分析。结果本组中,肾结石251例(22.8%)、输尿管结石742例(67.5%)、膀胱结石97例(8.8%)、尿道结石10例(0.9%)。上、下尿路结石的比例为9.28∶1。高钙尿患者27例(13.0%)、高钙血症91例(9.1%)、高尿酸血症167例(17.8%)。结石成分分析结果:草酸钙168例(62.7%);磷酸钙59例(22.0%);尿酸及尿酸盐25例(9.3%);磷酸镁铵10例(3.7%);碳酸盐5例(1.7%);胱氨酸1例(0.4%)。治疗:ESWL658例(59.8%)、肾切开取石术35例、肾切除术6例、输尿管切开取石术92例(占8.4%)、输尿管镜加气压弹道碎石52例(4.7%)、膀胱切开取石53例(其中前列腺摘除术加膀胱切开取石术26例);膀胱镜加气压弹道碎石20例;前列腺电切术加气压弹道碎石7例;膀胱镜加大力钳碎石术9例。尿道切开取石术1例;经尿道镜取石术2例;尿道镜加气压弹道碎石3例。结论本组尿石症患者以上尿路结石为主,含钙结石占绝大多数。尽管微创手术的普遍开展,ESWL仍不失为一种创伤小、效果好的治疗方法。     

Endoscopic sphincterotomy for common bile duct stones: Impact of recent technical advances

Technical improvements, such as mechanical lithotripsy, stenting or nasobiliary drainage, and wire-guided cannulation, have reduced the risk of complications in endoscopic sphincterotomy. To determine the extent of this reduction in risk, we assessed the medical records of 1352 patients with common bile duct stones in whom the procedure was conducted. Complications examined were: acute cholangitis and pancreatitis. Stone clearance was achieved in 1256 patients (92.8%), with an overall morbidity rate of 7.7% and a mortality rate of 0.15%. One hundred and forty-two patients had stones with a diameter greater than 20mm; 97 of these patients did not undergo lithotripsy. Cholangitis occurred in 10 of these 97 patients (10.3%), whereas, in the 45 patients who underwent lithotripsy, there were no cases of cholangitis (P=0.02). Stone removal was not immediately accomplished or attempted in 396 patients. In 82 of these patients in whom a stent or a nasobiliary drain was placed in the common bile duct, the incidence of cholangitis was 1.2%, significantly less (P=0.045) than the incidence of 6.4% in the other 314 patients given no stenting or nasobiliary drain. To overcome difficult cannulation, precut sphincterotomy was conducted in 134 patients and wireguided sphincterotomy, a recently introduced procedure, was conducted in 55 patients. When the precutting technique was used, the incidence of acute pancreatitis was significantly higher (8/134; 6.0%) than that in the patients in whom the standard procedure was conducted, i.e., neither the precut technique nor wire-guided ES was used (23/1218; 1.9%) (P=0.008). There were no cases of pancreatitis in the 55 patients in whom wire-guided sphincterotomy was performed, although the difference was not statistically significant because of the small number of patients (P=0.06). Based on these findings, we conclude that improved technologies have led to a significant reduction of complications in endoscopic sphincterotomy.     

ELECTROHYDRAULIC LITHOTRIPSY: AN EFFECTIVE AND ECONOMICAL MODALITY OF ENDOSCOPIC URETERIC LITHOTRIPSY

Background : Electrohydraulic lithotripsy (EHL) has been available for endoscopic treatment of urinary calculi since 1960, but the large probe size and concerns regarding safety had previously restricted its use to the treatment of bladder calculi. However, recent refinements have made it particularly suitable for the treatment of ureteric calculi. Methods : The authors report their initial experience using EHL in conjunction with mini-ureteroscopy in the treatment of 94 ureteric calculi in 89 patients. The size of the calculi ranged from 3 to 19 mm in diameter, with a mean of 8.2 mm. The mean operating time was 29 min, ranging from 10 to 120 min. Results : A complete fragmentation rate of 91.5% of the calculi was achieved. There were no major complications and a low incidence of minor complications: haematuria (2.2%), urinary tract infection (3.4%) and postoperative ureteric colic (2.2%). There were four cases of minor ureteric perforations (4.5%); all were successfully treated using conservative measures. Conclusions : It is concluded that EHL is a safe and effective method of treating ureteric calculi.     

输尿管镜治疗输尿管结石185例

目的探讨输尿管镜气压弹道碎石治疗输尿管结石的效果。方法2004年2月～2005年3月，我们对185例输尿管结石（其中伴肾绞痛96例）采用输尿管镜取石或气压弹道碎石进行总结和分析。结果失败12例，其中6例改开放手术，6例术后3d行体外冲击波碎石。一次碎石成功率93．5％（173／185），其中上段结石为75．0％（24／32），中段为95．8％（46／48），下段为98．1％（103／105）。肾绞痛者成功率为100％（96／96）。术中输尿管损伤率2．9％（5／173），其中3例（1．7％）中转开放手术。术后肾绞痛1例。全组随访6～12个月，平均10．2月，无复发。结论输尿管镜气压弹道碎石安全有效，并发症少，是治疗输尿管中下段结石的首选方法，尤其对肾绞痛者疗效更好。     

尿结石理化性质检测在体外冲击波碎石中的意义

对３２例的尿结石采用化学定量分析法进行化学成分分析，利用材料力学原理和方 法测定密度、硬度和抗压强度，并对其中１３例的尿结石作体外碎石试验。结果表明碎石所需 冲击次数与结石成分有关，尤其是草酸钙结石所需冲击次数明显增加；冲击次数与结石物理特 性有关，随结石硬度增加而增加。因此，检测尿结石理化性质在体外冲击波碎石中具有重要意 义。