Transureteral lithotripsy in pediatric practice

PURPOSE: The present study reviews ureteroscopy intervention for the treatment of ureteral stones in pediatric patients in the last 6 years at three institutions in Iran. PATIENTS AND METHODS: Sixty-six ureteroscopies were performed in 66 prepubertal patients (mean age 9 years; range 2-15 years) with a male/female ratio of 31/35. Ultrasonography, plain film, or intravenous urography was performed in all cases. The mean stone size was 8 mm (range 5-15 mm). All the interventions were performed under general anesthesia with semirigid ureteroscopes of 8F to 11.5F. The stone was located in the left ureter in 32 patients and in the right in 34 patients. Stones were located in the distal ureter in 59 patients, in the midureter in 5, and in the proximal ureter in 2. Before ureteroscopy, ureteral dilatation with a balloon was done to 12F if necessary. If the calculus could not be removed with the basket (stone.8 mm), lithotripsy using ultrasonic, electrohydraulic (EHL), or pneumatic equipment was performed. RESULTS: Ureteroscopy with an 11.5F, 9F, 8.5F, or 8F ureteroscope were performed in 26, 14, 5, and 21 patients, respectively, and ureteral dilatation was necessary in 23, 0, 0, and 2 cases, respectively. We were unable to introduce the ureteroscope into the ureter in three patients (two boys with an 11.5F ureteroscope and one girl with an 8.5F ureteroscope) with distal ureteral stones. The stones moved to the kidney in four patients. Stone management was with basketing alone in 14, EHL in 3, ultrasonic lithotripsy in 8, and ballistic lithotripsy in 34 patients. The stone-free rate was 88% (58 patients) at 48 hours postprocedure. The complication rate was 23% and included renal colic (1), gross hematuria (11), and pyelonephritis (3). No patient had obvious perforation or stricture of the ureter at 3-month follow-up. CONCLUSION: Our series demonstrates the high success rate that can be achieved with ureteroscopic removal of ureteral calculi in children. Ureteroscopic treatment, especially with a small-caliber ureteroscope, should be considered the first choice for treatment of calculi in the distal ureter in children.     

Ureteric calculi in children: preliminary experience with holmium:YAG laser lithotripsy

OBJECTIVE: To determine the efficacy and safety of holmium:YAG laser lithotripsy in children with ureteric calculi. PATIENTS AND METHODS: Between 1999 and 2003, 28 ureteroscopic laser procedures were carried out on 26 children (14 boys and 12 girls, mean age 6.5 years) with ureteric calculi. The mean (range) stone size was 1.21 (0.4-2.2) cm. At ureteroscopy the calculi were in the upper ureter in six (23%), mid-ureter in five (19%) and lower ureter in 15 (58%) patients. A rigid 8 F ureteroscope was used and the Ho:YAG laser energy delivered at 0.6-1.4 J and 6-10 Hz. All patients were evaluated after 3 months with intravenous urography to confirm stone clearance and to exclude ureteric stricture formation. RESULTS: The overall stone-free rate was 92% (24 children) after 28 ureteroscopic procedures. Stones were completely cleared in 83%, 80% and 100% of the procedures in the upper, mid- and lower ureters, respectively. In two children the procedure failed; they were salvaged by ureterolithotomy in one and extracorporeal shockwave lithotripsy in the other. During the procedures, a ureteric perforation was caused by several factors, including a technically difficult procedure and higher laser energy. At the mean (range) follow-up of 18 (3-39) months, low grade vesico-ureteric reflux was detected in two children, and there were no ureteric strictures in any. CONCLUSION: Holmium:YAG laser lithotripsy is an efficient and safe treatment for ureteric calculi in children.     

Electrohydraulic lithotripsy of ureteral calculi: the Stony Brook experience

We have used electrohydraulic lithotripsy for the treatment of ureteral calculi in a total of 29 patients. By combining the use of a 3.0 Fr electrode and a 9.5 Fr rigid ureteroscope, we have been able to successfully treat the majority of our patients with ureteral calculi. Bypass stenting of obstructing ureteral stones aided in access and effectiveness of ureteroscopy and endoscopic lithotripsy. The success rate in our series of 30 primary treatments was 80%; failures were primarily related to stone composition. In summary, we have found electrohydraulic lithotripsy of ureteral calculi to be a safe and effective treatment modality and routinely used it for stones throughout the length of the ureter that were either impacted or too large to extract primarily.     

Clinical experience with a new pulsed dye laser for ureteral stone lithotripsy

We treated 45 patients (46 ureteral stones) with a new pulsed dye laser. A 250 mu. fiber was used through a rigid (40 stones) or flexible (6) ureteroscope. Stones were in the upper (5 cases), middle (5) or lower (36) third of the ureter. Stone composition was calcium oxalate dihydrate (34 patients) or monohydrate (7), struvite (2) or uric acid (2). Of the calculi 36 (78%) were fragmented, including 14 that also required simultaneous basket removal of fragments. Ten stones were not fragmented: 6 because of the pure monohydrate composition and 4 due to malfunction of the laser. No damage to the ureteral wall was noted. Retrograde rigid ureteroscopy with laser lithotripsy was effective for lower and middle third ureteral stones. Flexible ureteroscopy with laser lithotripsy was effective (impacted stones) but difficult for upper third ureteral stones.     

输尿管软镜钬激光碎石联合排石颗粒治疗肾结石的临床研究

目的 观察输尿管软镜钬激光碎石联合应用排石颗粒治疗肾结石的疗效.方法 将本科室2013年8月至2015年8月收治的192例行输尿管软镜钬激光碎石的肾结石患者随机分为观察组(101例)和对照组(91例).结石最大直径约<25 mm,术前均行泌尿系平片(KUB)+静脉尿路造影(IVU).对照组60例结石位于上盏、中盏或肾盂内,41例位于下盏或多个肾盏,采用输尿管软镜钬激光碎石.观察组60例结石位于上盏、中盏或肾盂内,31例位于下盏或者多个肾盏.采用输尿管软镜钬激光碎石术,术后联合排石颗粒治疗.术后4周KUB平片或者双肾CT平扫,评估结石清除率.结果 全部患者进镜顺利并成功碎石.观察组4周后总排石成功率为97.0% (98/101) ,下盏及多盏结石排净率为97.6%(40/41),肾中上盏及肾盂内结石的排石率为96.7%(58/60);对照组4周后总排石成功率为90.1% (82/91),下盏及多盏结石排净率为80.6%(25/31),肾中上盏及肾盂内结石的排石率为95.0%(57/60) .两组相比总排石率差异具有显著统计学意义(P<0.05),下盏及多盏结石排净率差异具有显著统计学意义(P<0.05),肾中上盏及肾盂内结石的排石率无明显差异(P>0.05).结论 输尿管软镜激光碎石治疗肾结石尤其是肾下盏结石术后联用排石颗粒可明显提高排石率.     

输尿管软镜联合钬激光碎石术治疗肾和输尿管上段结石:附86例报告

目的 评价输尿管软镜联合钬激光治疗上尿路结石的效果及影响碎石成功的因素和技巧.方法 2008年7月至2011年6月86例输尿管软镜钬激光碎石病例.共104枚结石,结石最大直径10~25 mm.术中使用输尿管硬镜探查患侧输尿管,放置输尿管软镜鞘并换用Storz Flex-X2 F7.5输尿管软镜.若输尿管鞘无法插入,可直接在导丝引导下插入输尿管软镜至肾盂.如果软镜仍不能直接插入,则在放置导丝后留置6 F双J管,1~2周后第二次试行输尿管软镜碎石.术后4周复查KUB或双肾CT平扫,评估碎石效果.结果 软镜一次进镜成功率87.2%(75/86),余11例第二次手术9例成功进镜,总的进镜成功率为97.6%(84/86),钬激光碎石成功率95.3%(82/86).4周后结石清除率为83.7%02/80.12例再次行输尿管软镜碎石,其中9例排净结石.总的结石清除率为94.1%(81/86).平均手术时间为45 min(18-75 min).无严重并发症.结论 输尿管软镜钬激光碎石是治疗10~25mm肾和输尿管上段结石的安全有效的方法.其结石排净率高、并发症低,可以作为体外冲击波碎石失败和经皮肾镜碎石术后残留结石的治疗选择.     

Ureteroscopic management of ureteral calculi in children

PURPOSE: To evaluate the efficacy and safety of rigid ureteroscopy for the treatment ureteral calculi in children. PATIENTS AND METHODS: Between January 2002 and January 2006, 16 boys and 25 girls with an average age of 9.5 years (range 3-15 years) were treated with a 95F rigid ureteroscope for stones 4 to 10 mm (mean 5.6 mm) in 46 renoureteral units (RUUs), and the results were evaluated. The stones were located in the upper ureter in 4 RUUs, the middle ureter in 15, and the lower ureter in 27. Dilatation of a tight ureteral orifice was necessary in 17 cases (36.9%). RESULTS: On examination during ureteroscopy, all calculi were well fragmented, and in 33 patients (94%), stone fragments were removed directly. Stones were fragmented with pneumatic lithotripsy in 23 RUUs and removed by forceps with or without fragmentation in the remaining 23. Whereas the treatment was successful in 36 children (87.8%), it was unsuccessful in 5 (12.2%) secondary to bleeding and mucosal injury in 3 children (7%; 1 middle- and 2 upper-ureteral stones) and severe ureteral stenosis with kinking in 2 (4.8%; 1 middle- and 1 upper-ureteral stone) children. In two other cases, although the fragments in the upper portion of the ureter could be reached with the ureteroscope, the stones migrated into the renal collecting system during pneumatic lithotripsy and were treated successfully with subsequent SWL (4.8%). At the end of the procedure, a 4.8F Double-J stent was left in place in 9 cases. There were no serious complications, and the children were not specifically evaluated for postoperative vesicoureteral reflux. Follow-up ranged from 1 to 36 months with an average duration of 22.4 months. CONCLUSION: With the aid of the experience gained in the adult population and careful instrumentation, we believe that, in skilled hands, rigid ureteroscopy can be applied in a safe and efficient manner for stones located in different portions of the pediatric ureter.     

The impact of extracorporeal piezoelectric lithotripsy on the management of ureteric calculi: an audit

The presentation and management of 153 patients with ureteric calculi requiring active treatment over a 12-month period were reviewed; 74% of patients had primary ureteric calculi and 26% had ureteric calculi composed of fragments resulting from extracorporeal piezoelectric shockwave lithotripsy (EPL) to renal calculi; 32 patients (21%) had more than 1 calculus or a steinstrasse. The primary procedures included were in situ EPL (n = 54), push-bang (44), retrograde ureteroscopy (40), Dormia basket extraction (6), push-pull (1), antegrade ureteroscopy (1) and combinations of these (7). The success of the primary procedure could not be predicted from stone size, site or duration in the ureter, but upper tract dilatation was significantly less (p less than 0.01) in the successful group. The overall success rate for complete stone extraction was 97%, but 54 patients (35%) required more than 1 procedure to achieve this. In situ EPL and push-bang, as either primary or secondary procedures, were successful in treating 79 patients (52%); 2 patients required ureterolithotomy (1.3%). The overall complication rate was 18%. Since EPL is only successful in treating approximately half of ureteric calculi, a range of other treatments should be available to maintain a low rate of open surgery.     

Management of the impacted ureteral calculus

The management of 42 impacted ureteral calculi is reviewed. Impacted stones were defined by the inability to pass a guide wire or catheter on initial attempts. Stones were impacted in the upper ureter in 10 patients, mid ureter in 11 and lower ureter in 21. Upper ureteral stones were treated in 8 patients by extracorporeal shock wave lithotripsy after disimpaction by laser or other techniques. Mid ureteral stones were treated by laser alone in 7 patients and by extracorporeal shock wave lithotripsy after disimpaction in 4. Lower stones were treated by laser in 17 patients and ultrasound in 2. Complications included 3 major and 5 minor perforations, and 4 false passages. Treatment was successful without an open operation in 40 of 42 patients (95%). Our current approach to impacted ureteral calculi involves passing a rigid ureteroscope to the stone, with disimpaction performed by laser fragmentation or other dislodgement maneuvers. Proximal stones or large fragments then are treated by extracorporeal shock wave lithotripsy. Mid ureteral stones are treated similarly, unless they are so fragile that in situ fragmentation may be completed easily. Lower ureteral stones are fragmented in situ, with hard fragments extracted by basket. Alternative treatments for impacted calculi at all levels include unstented in situ extracorporeal shock wave lithotripsy, antegrade ureteroscopy and, finally, an operation.     

Extracorporeal lithotripsy of ureteric calculi using the Dornier HM-3 lithotriptor.

Over a 5-year period (November 1984-November 1989), we treated 356 patients with ureteric calculi; 170 were treated by extracorporeal shock wave lithotripsy (ESWL) on a Dornier HM-3 lithotriptor. The calculi (n = 176) were uniformly distributed along the length of the ureter: 44 were just below the pelviureteric junction, 59 were lumbo-iliac, 42 were in the upper bony pelvis and 32 in the lower bony pelvis. The mean diameter of the upper ureteric calculi was 10 mm and for the others it was 8 mm. Thirty-four patients with acute obstructive pyelonephritis required pre-ESWL drainage of the urine. X-ray localisation required intravenous urography during lithotripsy in 52 cases (30%). On plain X-ray the following day 170 stones (96%) were judged to have disintegrated. The 6 patients whose stones were not fragmented received further treatment (ureterotomy (4) and ureteroscopy (2)). Five patients required additional treatment because of pain or fever (catheterisation (3) and ureterotomy (2)) and 2 patients had a second lithotripsy owing to insufficient fragmentation. Four patients were lost to follow-up. In 153 patients (90%) the fragments were eliminated completely, 146 in the first month and the remainder before the sixth month. No serious sequelae were observed. In addition to the 5 patients who required supplementary treatment. 11 patients with pain or fever needed medical treatment. We recommend first intention in situ ESWL for all ureteric calculi.     

气压弹道碎石术治疗输尿管结石

目的 探讨输尿管镜下气压弹道碎石术治疗输尿管结石的效果。方法 应用输尿管镜下气压弹道碎石治疗输尿管结石180例。男127例，女53例，年龄14～62岁，平均38岁。输尿管上段结石18例，中段64例，下段98例。结石直径0．5～2．3cm，平均0．7cm。合并患侧肾积水89例，其中1例女性双侧输尿管下段结石并梗阻、双肾积水，肾功能不全。结果 180例输尿管结石粉碎率98．3％(177例)，1次彻底清除率91．7％(165例)，3例结石移至肾盂者未完成手术，12例术终输尿管壁残留结石粉末，术后4周IVU复查，残石已排空。67例(37．0％)术后有肉眼或镜下血尿，多于1～2d内消失。180例均无穿孔、感染等并发症。结论 输尿管镜直视下气压弹道碎石术治疗输尿管结石确切、安全、组织损伤小，清除彻底、并发症少，可作为输尿管中段和下段结石的首选治疗方法。     

Treatment of ureteral calculi with ballistic lithotripsy

BACKGROUND AND PURPOSE: Ballistic lithotripsy is one of the new intracorporeal lithotripsy methods. In this study, the efficacy and complications of this method in the management of ureteral calculi were evaluated. PATIENTS AND METHODS: From November 1999 to December 2001, 340 patients (mean age 39.8 years; range 1.5-82 years) with a total of 362 ureteral calculi (bilateral in 22 cases) were treated with an 8.5F rigid ureteroscope and the Swiss Lithoclast. Of the calculi, 115 (32%) were located in the upper ureter, 63 (17%) in the middle ureter, and 184 (51%) in the lower ureter. The mean stone size was 10.4 mm (range 5-22 mm). RESULTS: Nearly all (344; 95%) of the calculi were accessible with the ureteroscope, and 321 calculi (88.7%) were fragmented completely, either with no residual fragments or with residual fragments <3 mm. In 3 cases (0.8%), there were residual fragments of about 4 mm after the procedure that passed spontaneously. Twenty calculi (5.5%) migrated to the kidney during the procedure and were subsequently treated with adjuvant SWL. Major complications occurred in 2 cases (0.54%): ureteral perforation and stenosis in 1 patient each. The 2-week stone-free rate was 89.5% (324/362). CONCLUSION: Lithoclast ballistic lithotripsy is a safe and effective approach for the treatment of ureteral calculi regardless of composition.     

Anterograde ureteroscopy in the extraction of lumbar ureteral calculi

Antegrade ureteroscopy can be used to extract certain lumbar ureteric stones in which the only alternative treatment is surgery. The technique of caliceal puncture is that of percutaneous nephrostomy: the ureteroscope is introduced through the Amplatz tube. The ureteric stone is removed by a basket probe, two-pronged forceps or hydroelectric shattering, 16 patients have undergone antegrade ureteroscopy; a rigid ureteroscope was used in 9 cases (2 residual fragments including 1 which migrated) and a flexible ureteroscope was used in 7 cases (3 failures). The overall success rate for the technique of 68% should improve with better selection of the indications (stone with a maximum diameter of 12 mm without retraction of the adjacent ureter and without kinking of the excretory tract) and with greater experience of the operators.     

输尿管镜气压弹道碎石术治疗输尿管结石

目的评价输尿管镜气压弹道碎石术（URSL）治疗输尿管结石的临床疗效。方法使用输尿管镜下气压弹道碎石术治疗输尿管结石170例，输尿管上段结石10例，输尿管中段结石42例，输尿管下段结石118例，结石最大直径2．2cm，平均1．0cm，合并患侧肾积水80例，伴肾绞痛77例，平均病史为24周。结果一次性碎石成功率90．5％（154例）；10例输尿管壁残留小结石，术后1个月复查静脉肾盂造影（IVU），残石已排净；2例较大残余结石上移至肾盂行体外冲击波碎石（ESWL），1个月内结石排净；4例改开放手术，2例为结石被息肉严重包裹碎石失败，2例结石远端严重狭窄；均无输尿管穿孔、撕裂、假道、撕脱等并发症；随访9—12个月，肾积水病例积水情况明显改善；伴肾绞痛病例症状消失；未见结石复发病例。结论输尿管镜气压弹道碎石术治疗输尿管结石疗效确切、安全。     

Extracorporeal shock wave lithotripsy with the Storz Modulith SL20: the first 500 patients.

Our initial experience of extracorporeal shock wave lithotripsy (ESWL) with the Storz Modulith SL20 is reported. A total of 500 patients with 551 renal and 120 ureteric stones, mean diameter 11.9 mm, underwent 746 treatments; 68.2% of patients required a single treatment. The mean treatment rate for renal calculi was 1.4 and for ureteric calculi it was 1.5, rising to 4.2 for staghorns; 62.2% of treatments were performed on an out-patient basis. Analgesia (intravenous fentanyl) was required in 60.9% of treatments for renal calculi but in only 38.2% of those for ureteric calculi. The overall stone-free rate at 3 months was 77.6%, with a further 14.7% of patients having fragments less than 3 mm in diameter that required no further treatment. The stone-free rate was dependent on the site of the stone, with the majority of residual fragments lying in a lower pole calix. There were few complications. The Modulith is an efficient and safe lithotripter capable of treating stones in the kidney and throughout the ureter.     

Use of the holmium:YAG laser for ureterolithotripsy in children

OBJECTIVE: To review our experience with rigid ureteroscopy and holmium:YAG laser for treating ureteric calculi in children. PATIENTS AND METHODS: The study included 35 children who were treated with rigid ureteroscopy for ureteric calculi between November 1997 and June 2003 (15 boys and 20 girls; mean age 6.2 years, range 1-14). The mean (range) stone size was 8 (4-15) mm and the duration of anaesthesia 46.6 (15-90) min. The stone was in the distal third of the ureter in 33 children and in the proximal third in two. We used a 7.5/8/10 F rigid ureteroscopes with routine dilatation of the ureteric orifice. For lower ureteric stones, lithotripsy was carried out with holmium:YAG laser in 29 cases, a pneumatic impactor in two and forceps extraction in two. Both stones in the proximal ureter were pushed back into the collecting system. All the ureters were stented using JJ stents in 31 and ureteric catheters in four cases. The mean postoperative follow-up was 12 (2-30) months. RESULTS: Excluding the two stones pushed back, the stone-free rate after a one-stage procedure was 82% (27/33). With repeated procedures in the six (ESWL in two) remaining cases the success rate was 97% (32/33). The ureter was perforated in two patients within the first five in the series. There was no pyelonephritis or gross haematuria after surgery. CONCLUSION: Ureteroscopy and lithotripsy using the holmium:YAG laser is effective and safe for treating ureteric stones in children, in experienced hands. The results would be even better using smaller and flexible ureteroscopes.     

组合式输尿管软镜联合钬激光治疗上尿路结石

目的评价组合式输尿管软镜联合钬激光治疗上尿路结石的安全性及临床疗效。 方法收集2015年4月至2017年4月我院采用组合式输尿管软镜治疗433例上尿路结石患者的临床资料。单发性结石178例,多发性结石255例;肾中上盏132例,肾下盏结石97例,输尿管上段及肾盂结石204例。结石直径为0.8～4.0 cm。 结果一次性进镜成功率100%,手术时间30～280 min,术后住院时间1.0～5.0 d。1例结石未寻及,改为体外冲击波碎石。3例光纤无法触及结石,均改为经皮肾镜术。其他429例均实施组合式输尿管软镜术。术后2周复查腹部平片或泌尿系CT平扫,结石排净率84.4%（362/429）,二次手术37例,最终结石清除率为89.9%（386/429）。未发生输尿管穿孔、撕脱及大出血等严重并发症。 结论组合式输尿管软镜联合钬激光治疗上尿路结石临床应用安全,疗效理想,可作为输尿管上段结石及肾结石的理想治疗方案,具有很好的临床应用价值。     

输尿管镜用于中下段输尿管结石治疗的临床分析

目的探讨输尿管半硬镜联合钬激光碎石、套石蓝取石在输尿管中下段结石治疗中的安全、有效性。方法回顾分析2004～2011年间800例输尿管中下段结石患者的临床资料并比较各类输尿管镜联合不同碎石、取石技术的治疗效果,其中气压弹道碎石340例,钬激光碎石460例。结果输尿管半硬镜下钬激光碎石联合套石蓝取石术放镜成功率100%、平均手术时间（34.2±10.3）min、结石移位率1.3%、管壁损伤率1.1%、中转开放术率0.4%、术后残石率0.9%,主要技术指标均优于传统输尿管镜气压弹道碎石术。结论输尿管半硬镜联合钬激光碎石、套石蓝取石技术治疗输尿管中下段结石便捷、安全、高效,值得临床推广。     

预示输尿管镜碎石手术上镜失败的临床因素分析

目的探讨输尿管镜碎石手术时因管腔细小造成输尿管镜上镜失败的相关临床因素。 方法回顾性分析我院2018年5月至2019年8月同一术者行输尿管镜碎石手术病例的临床资料，手术使用8/9.8 F输尿管硬镜，根据上镜成功或失败分组并进行相关资料的比较。 结果输尿管镜碎石手术患者共102例，其中上镜成功91例，失败11例，一次上镜失败率10.8%。两组在年龄、性别、身高、体重及体质量指数（BMI）、糖尿病发生率、术前ESWL史、自然排石史和输尿管镜操作史、结石纵径等方面比较差异均无统计学意义（P>0.05）。成功组结石横径显著大于失败组[（7.7±1.4）mm vs （5.8±1.1）mm，P<0.001]；上段结石患者失败率最高，为30%（9/30），显著高于中段3.7%（1/27）和下段2.2%（1/45） （P<0.001）；而上段结石患者中，失败组横径显著小于成功组[（5.9±1.2）mm vs （8.4±1.4）mm，P<0.001]。进一步行多因素逐步Logistic回归分析表明结石横径（P=0.027）和结石位置（P=0.042）是上镜失败的危险因素。 结论结石位于输尿管上段且结石横径较小预示管腔细小导致输尿管镜上镜失败的可能性大，术前应充分预估。     

输尿管硬镜钬激光治疗输尿管结石

目的:通过分析输尿管硬镜钬激光输尿管结石的治疗效果,评价其临床应用价值。方法:应用WolfF8/9.8输尿管硬镜,德国Wavelight Auriga钬激光治疗仪,365～600μm光纤,激光能量500～1 200mJ,频率5～12Hz治疗406例输尿管结石患者,随防1～30个月,分析总结治疗效果。结果:除9例输尿管镜检查时结石回流入肾内,无法碎石,10例因输尿管结石远端狭窄,输尿管镜未能到达结石部位改其它方法治疗,余病人均一次成功。手术时间8～63min,平均21min。术后合并症有血尿304例,多3天内消失,最长1例血尿13天;尿痛316例,1～6天消失;发热18例,多3天后正常。术后放置双J管14～150天,平均30天。4例肾内结石行体外冲击波碎石(ESWL)。结石排净率上段89.29%(100/112),中段95.10%(136/143),下段98.68%(149/151)。结论:输尿管硬镜钬激光治疗输尿管结石创伤小,效果好,采用高频率低能量可降低上段输尿管结石返流肾内的的发生率。