Stone measurement by volumetric three‐dimensional computed tomography for predicting the outcome after extracorporeal shock wave lithotripsy

OBJECTIVE

To evaluate the efficacy of stone volume measured using a three‐dimensional (3D) reconstruction of preoperative non‐contrast computed tomography (NCCT) as an independent predictor of success after extracorporeal shock wave lithotripsy (ESWL) of upper urinary tract calculi.

PATIENTS AND METHODS

We evaluated preoperative NCCT in 94 patients who had ESWL for solitary upper urinary tract calculi of 4–20 mm in diameter. Axial images were used to measure the skin‐to‐stone distance (SSD), Hounsfield Unit (HU) density and axial stone diameter. Stone volume was calculated on a volume‐rendered 3D image for each stone. Maximum stone length was determined by comparative measurements of each stone in coronal, sagittal and axial planes, and was also measured on a plain abdominal film before ESWL. For ESWL we used the DoliS lithotripter (Dornier Medical Systems, Marrietta, GA, USA). A plain film at 6 weeks was used to categorize patients as stone‐free (SF) or with residual stone.

RESULTS

In all, 58 (62%) patients were SF and 36 (38%) had RS; the mean stone volume was significantly different between these groups (274 vs 464 µL, P = 0.002). Logistic regression analysis showed that stone volume was the strongest predictor of SF status (P < 0.001), compared to peak HU (P = 0.015), mean HU (P = 0.04) and axial stone diameter (P = 0.006). The body mass index, SSD and maximum stone length on NCCT or a plain film did not predict success. A stone volume of <500 µL best predicted treatment success (P < 0.001) with 72% of patients with a stone volume of <500 µL having a successful outcome, vs only 27% with a stone volume of >500 µL.

CONCLUSION

Our study suggests that stone volume is an optimal predictor of SF status after ESWL of solitary upper urinary tract calculi.     

体外冲击波碎石术治疗肾感染石

作者采用体外冲击波碎石术连续性治疗72例肾感染石,观察其疗效。部分性鹿角结石69例,完全性鹿角结石3例.总共93枚,直径1.4～4.7cm,平均2.2 cm。在16例结石体积较大的患者中,术前15例放置双J管,1例放置Dormia支架、单次治愈者63.89％(46例),2次者19.44％(14例),3次者9.72％(7例),4次者2.78％(2例),5次者2.78％(2例),失败者1.39％(1例)。术后因尿路感染发热者9例,均用抗生素治愈。作者认为,采用体外冲击波治疗肾感染石是一种安全有效的方法。并侧重探讨了碎石过程中的定位技术和冲击方法以及有关尿路感染的预防和治疗。     

Efficacy of extracorporeal shock wave lithotripsy for solitary lower calyceal stone: a statistical model

OBJECTIVE: To evaluate the effect of inferior calyceal radiographic anatomy, number of extracorporeal shock wave lithotripsy (ESWL) sessions and stone size on the successful clearance of solitary inferior calyceal calculi after ESWL. PATIENTS AND METHODS: In a prospective study between January 2001 and November 2002, 66 renal units with a solitary inferior calyceal calculus of < or = 2 cm were treated with electrohydraulic ESWL. The infundibulopelvic angle (two definitions), infundibulovertebral angle, inferior calyceal infundibular diameter, infundibular length, cortical thickness over the lower pole, number of minor calyces and stone size were determined from intravenous urography before treatment. The number of ESWL sessions was also included in the analysis. Treatments which produced residual fragments not clearing within 3 months of satisfactory fragmentation were considered as failures. All patients in whom the treatment failed were treated successfully by percutaneous nephrolithotomy. The data were then analysed using two different statistical methods; first by intravariable differences using the test of proportion (Fisher's test) and then all the variables together using logistic regression. RESULTS: At 3 months 78.8% of the renal units were clear of stone. All intravariable differences were statistically significant except stone size (<1 cm, 1-2 cm). In a multivariate analysis of all variables, only stone size was the most important predictor for successful stone clearance (P = 0.03). CONCLUSIONS: ESWL is the initial treatment of choice in selected patients with inferior calyceal stones. The stone size appears to be the most important predictor for stone clearance.     

CT值对输尿管结石ESWL疗效的预测价值

目的：了解非增强螺旋CT的结石CT值对输尿管结石ESWL疗效的预测价值。方法：对34例结石长径在0．4～1．2cm之间拟行ESWL治疗的输尿管下段单发结石患者,先进行非增强螺旋CT检查,测定结石CT值,分为CT值〈700HU组和〉700HU组,ESWI,后经复查,计算两组结石清除率,统计学分析两组间的基本特征和冲击次数、结石清除率差异。结果：与结石CT值〉700HU组相比,〈700HU组所需冲击次数少,结石清除率高。结论：非增强螺旋CT的结石CT值能预测输尿管结石ESWL后的结石清除率。CT值低者易于粉碎和排空,CT值高者结石清除率低,可考虑首选输尿管镜下碎石或开放手术取石。     

超声联合气压弹道碎石术治疗复杂性肾结石(附78例报道)

目的:探讨经皮肾镜下超声联合气压弹道碎石术治疗复杂性肾结石的方法及疗效。方法:B超引导下穿刺并扩张建立F22经皮肾镜操作通道,在F20.8肾镜下采用瑞士第三代EMS超声气压弹道碎石机,争取一期粉碎结石并主动吸出体外。结果:78例83侧肾结石,单侧结石清除时间43~156min,平均89min。结石粉碎率100%,结石取净率85.6%(71/83)。术后随访1~9个月,平均5.6个月,均无严重并发症如出血及感染,亦无结石复发。结论:经皮肾镜超声联合气压弹道碎石术可以明显地提高复杂性肾结石取石的效率,降低结石的残余率,具有高效、安全、微创的特点,有较好的推广应用价值。     

An investigation of factors associated with failure of extracorporeal shock wave lithotripsy for ureteral calculi

In this study, we attempted to determine which patients with ureteral calculi are likely to have an unsuccessful outcome for extracorporeal shock wave lithotripsy (ESWL). The records of 388 patients with ureteral calculi treated with ESWL at Ijinkai Takeda General Hospital between January 1997 and December 1998 were retrospectively reviewed. Three hundred seventeen patients had been treated with ESWL alone (single session 156, multiple sessions 161) and 71 with transurethral ureterolithotripsy (TUL) due to failure of ESWL. We compared these two groups by multivariate logistic regression analysis, which revealed that (1) middle and lower ureteral calculi, (2) stones > 8 mm, (3) moderate to severe hydronephrosis and (4) failure of the first session ESWL were factors associated with poor outcome of ESWL. Although each predictive value of these factors was relatively low (29.6-38.6%), the rate of failure of ESWL was 85.0% when patients had all four factors. We therefore recommend an early change in treatment modality to TUL for patients with ureteral calculi when all four risk factors listed above are present.     

Laser lithotripsy of the difficult ureteral calculus: results in 122 patients.

We studied 122 patients with ureteral calculi who could not be treated by extracorporeal shock wave lithotripsy (ESWL) because the stones could not be localized or focused for treatment, the patient had failed prior ESWL, the stones were impacted and in situ ESWL was likely to fail or the stones were proximal to a ureteral stricture. These patients underwent laser lithotripsy using the Candela pulsed dye laser. In 107 patients (88%) the calculi were completely fragmented with the laser alone, while 10 (8%) needed another procedure (ESWL in 8 and stone fragment extraction by basket in 2), and 5 (4%) had failed laser therapy and needed some other form of treatment (ESWL in 4 and percutaneous antegrade extraction in 1). At 3 months 116 of 122 patients (95%) were stone-free. There were 2 immediate complications (ureteral perforations) and 1 late complication (ureteral stricture). Laser lithotripsy is a safe and effective method of intracorporeal fragmentation, even of the difficult ureteral calculus, and it is a useful adjunct to ESWL.     

Electromagnetic extracorporeal shock wave lithotripsy in children

Extracorporeal shock wave lithotripsy (ESWL) was performed for the treatment of urinary tract calculi in 28 children. All treatments were done with the standard Siemens Lithostar device in situ: no special adaptations for adequate positioning of children are required to target the stone precisely. A total of 42 calculi in 30 renal units was treated, requiring 50 ESWL sessions. The mean energy used was 16.4 kv. and the number of shock waves averaged 3,188. Mean fluoroscopy time per session was 1.5 minutes. In 26 of 50 sessions (52%) general anesthesia was needed for the child to remain perfectly still. A complete stone-free rate was achieved in 38 of 42 calculi (90.5%): after 1 session in 30 (71.4%), after 2 sessions in 6 (13.7%) and after 3 sessions in 2 (4.8%). Five staghorn calculi were treated with ESWL monotherapy. A complete stone-free result was obtained after 3 treatments in 2 patients, while 2 had residual fragments in the lower pole (5 mm. after 6 sessions and 11 months of followup in 1, and 7 mm. after 3 sessions and 3 months of followup in 1). A cystine staghorn stone necessitated open nephrolithotomy after 3 sessions without any fragmentation. One impacted sacroiliac ureteral stone required endoscopic laser lithotripsy. Except for these 2 failures no adjuvant procedures were needed. There were no intraoperative or postoperative complications and minor skin bruising at the coupling site after 3 treatments did not require any therapy. We conclude that electromagnetic ESWL with the standard Lithostar unit is a safe and effective method to treat calculi throughout the urinary tract in children.     

Extracorporeal shock wave lithotripsy for cystine urolithiasis in children: Outcome and complications

The Siemens Lithostar Litotriptor was used to treat 6 children withcystine nephrolithiasis, previously treated by open surgery. Fivechildren had renal calculi (3 multiple caliceal, 2 pelvis) and one hadureteral calculus. Stone size ranged from 0.2–2.5 cm in diameter,and stone burden was from 0.24 to 10.81 cm³ per kidney. Fromone to 4 ESWL sessions per unit were applied, with a total of 1,800 to12,000 shock waves. The stone free rate at 3 months was 50%. Acomplete elimination was obtained with cystine stones in renal pelvisand ureter, however, up to 4 ESWL treatments failed in caliceal stones.Rather location of cystine calculi than previous surgery was associatedwith ESWL success rate. Two patients with positive urine cultures weresuccessfully treated with appropriate antibiotics before ESWL wasattempted. Perirenal hematoma was major complication demonstrated byradionuclide scintigraphy in one patient, and resolved spontaneously by3 months. In the combined treatment of cystine urolithiasis in childrenESWL, as auxillary procedure, was safe and effective in pelvis stone butfailed in caliceal stones. Medical dissolution for retained fragmentswas found effective.     

Atrophy of kidney following extra corporeal shock wave lithotripsy of renal calculus in a paraplegic patient with marked spinal curvature

OBJECTIVES: To discuss a rare complication of extra corporeal shock wave lithotripsy (ESWL) of renal calculus in a paraplegic patient, who had marked curvature of thoracic and lumbar spine. DESIGN: A case report of a paraplegic patient, who developed renal atrophy and hypertension after undergoing ESWL of staghorn calculus. SETTING: Regional Spinal Injuries Centre, Southport and Mersey Regional Lithotripsy Unit, Royal Liverpool University Hospital, Liverpool, UK. PARTICIPANT: A 28-year-old male with spina bifida, paraplegia at L-1 level and considerable curvature of spine and tilting of pelvis. METHOD: ESWL was carried out in three sessions by delivering 1934, 1876, and 2025 shock waves respectively. Localisation of the staghorn calculus was difficult because of spinal curvature and pelvic tilt. RESULTS: A follow-up IVU, performed 3 months after last ESWL treatment, revealed no residual stone in the left kidney, apart from a little low-density calcification in the renal parenchyma adjacent to the lower pole calyx. There were no calculi in the left ureter. The left kidney had become small, though still functioning. MAG-3 isotope renogram showed the left kidney to be markedly atrophic. Relative renal function: right kidney, 94%; and left kidney, 6%. He developed hypertension and a laparoscopic left nephrectomy was performed at another hospital. CONCLUSION: Difficulty in localisation of renal calculi for ESWL must be anticipated in spinal bifida and spinal cord injury patients, who have significant spinal curvature. Because of problems in the positioning of a patient with marked curvature of spine and pelvic tilt, and consequent difficulties in accurate localisation of renal calculi for lithotripsy, these patients may be at increased risk of developing renal parenchymal and vascular damage following ESWL.     

Current management of calculi in horseshoe kidneys

OBJECTIVES: To assess treatment options for calculi in horseshoe kidneys and the impact of extracorporeal shockwave lithotripsy (ESWL) on the management of renal stones. MATERIAL AND METHODS: From June 1971 to January 1998, 52 patients with horseshoe kidneys and calculi received treatment at our Urologic Stone Unit. There were 40 men (77%) and 12 women (23%). Average patient age was 41 years (range: 10-70 years). Clinical onset, treatment received and outcome were evaluated retrospectively. A successful outcome was defined as a patient without residual calculi or with fragments <0.4 cm in size. RESULTS: Clinical onset was mainly low back pain in 37 patients (71%). Eighty-nine stones were treated, i.e. an average of 1.7 treatments per patient. Before the ESWL era (May 1987), we performed two heminephrectomies, 16 pyelolithotomies, 12 pyelolithotomies combined with ureteropyeloplasty and one percutaneous nephrolithotomy. Since the advent of ESWL, seven pyelolithotomies and three pyelolithotomies combined with ureteropyloplasty have been done. ESWL was used to treat 48 calculi. In three cases the patient was placed in the prone position due to difficulties in stone focusing. In 37 cases (77%) patients were either rendered stone-free or had residual fragments <0.4 cm in size. Urinary diversion for obstruction was carried out in two cases (4%). CONCLUSIONS: At present ESWL is the first-choice treatment for calculi in horseshoe kidneys. It involves no significant focusing difficulties and is associated with a low incidence of obstructive complications. Open surgery is indicated in cases of stone-related pyeloureteral stenosis and in the presence of calculi >2-2.5 cm in size.     

小儿肾结石的ESWL和PCNL治疗

目的　总结小儿肾结石ESWL和经皮微造瘘输尿管镜取石术 (mini PCNL)治疗经验。　方法　回顾性分析 10 5例小儿肾结石诊治资料 ,男 72例、女 3 3例 ,平均年龄 8.7岁。其中伴尿路畸形 2 1例 (2 0 .0 % )。ESWL治疗 68例 ;mini PCNL治疗 3 3例 ,4例联合ESWL ;改行开放手术 4例。　结果　 68例ESWL治疗 92次 ,结石完全排空 57例 (83 .8% ) ,1次ESWL治疗成功 47例 (69.1% ) ,2次治疗 18例 (2 6.5% ) ,3次治疗 2例 (4.4% ) ;2例石街经输尿管镜治疗成功。 3 3例mini PCNL治疗者 ,一期PCNL成功 2 4例 (72 .7% ) ,二期PCNL治疗 9例 (2 7.3 % ) ;3例伴肾盂输尿管连接部梗阻者同时行顺行肾盂输尿管内切开术 ,一期结石清除率 2 4例 (72 .7% ) ,二期结石清除率 2 9例(87.9% ) ,联合ESWL 4例 ,总结石清除率为 97.0 %。 4例开放手术中 2例同时行肾盂输尿管成形术 ,1例多发结石术后有残余结石。　结论　ESWL是治疗小儿肾结石安全、有效的首选方法 ;选择PCNL治疗应根据结石和设备技术情况 ,联合ESWL成功率更高     

Extracorporeal Shock Wave Lithotripsy in L-shaped Kidneys: Report of Two Cases

The L-shaped or tandem kidney is a type of crossed ectopia with fusion in which the crossed kidney assumes a transverse position during its attachment to the inferior pole of the other kidney. Calculus formation is a well-known sequel of congenital abnormalities of the urinary tract and we like to present two patients harbouring calculi in L-shaped kidneys treated by extracorporeal shock wave lithotripsy (ESWL). The first patient had a calculus in renal pelvis of the transverse kidney. The second case had multiple calculi in renal pelvis and calices of the vertically positioned kidney. After three sessions, first patient was stone free, whereas no fragmentation in the second case. As a conclusion, ESWL might be an option for L-shaped kidneys.     

Laparoscopic assisted percutaneous nephrolithotomy in ectopic pelvic kidneys

Abstract:   Three patients underwent laparoscopic assisted percutaneous nephrolithotomy (PNL). A kidneys, ureter and bladder (KUB), and intravenous pyelogram (IVP) of the first patient showed a 3 cm calculus in a right side ectopic pelvic kidney overlying on the sacrum. The second patient had bilateral ectopic kidneys. The right kidney was located in the true pelvis without calculi and the left kidney was located in the iliac cavity with a 2.5 cm calculus in the renal pelvis. The third one had a 4 cm stone in the infundibulum of the upper calyx of the left pelvic ectopic kidney. All of them had a history of failed shock wave lithotripsy after two sessions.
Then the patients were scheduled for laparoscopic assisted percutaneous removal of calculi. Under fluoroscopic control the best access route was located and the kidney was punctured. A 24F nephroscope was introduced and all calculi were disintegrated and removed. Operating time was 150, 120 and 110 min in cases 1, 2 and 3, respectively. Complete stone clearance was documented with a plain X-ray KUB film and ultrasonography.
Finally the patients underwent IVP three months following the operation. They were all well and there were no early or late complications.     

B超引导下经皮肾镜取石术治疗上尿路结石1289例临床总结

目的 探讨B超引导下PCNL治疗上尿路结石的有效性与安全性. 方法 2004年6月至2009年7月行超声引导下PCNL 1289例.其中输尿管上段结石386例;肾单发结石463例,多发结石355例,鹿角形结石85例.结石大小0.8 cm×1.2 cm～9.0 cm×5.3 cm,平均2.1 cm×3.1 cm.伴不同程度肾积水935例. 结果 1289例无中转开放及死亡.平均手术时间90(55～220)min,平均术中出血量175(60～800)ml.术中、术后输血31例,术后因出血行超选择性肾动脉栓塞术14例(1.09%).一期单通道取石1105例,二通道取石108例,三通道取石76例.一期结石取净率85.03%(1096/1289);193例结石残留者中,67例行ESWL,126例行二期PCNL,其中85例结石取净.总结石取净率91.62%(1181/1289).结论 B超引导下PCNL治疗上尿路结石具有定位准确、工作通道建立安全简便、结石取净率高、创伤小、并发症少等特点,手术适应证选择、手术技巧掌握、相应配套设施的保障是PCNL成功的关键.     

多发性多部位肾结石的体外冲击波碎石后加用经皮肾穿刺造瘘取石(附34例报告)

目的:探讨提高多发性多部位肾结石疗效的方法.方法:对34例多发性多部位肾结石采用ESWL治疗,对其中的未排净残石或未碎结石再联用PCNL治疗.结果:34例中,29例ESWL治疗3～6次排净结石,排净率为85.3%;4例经联用PCNL Ⅰ期清除残石或未碎结石,结石总排净率达97.1%.结论:经ESWL治疗后,再联用PCNL取净肾内残留结石来治疗多发性多部位肾结石,具清除率高、损伤少、安全性好、并发症少等优点,是一种经济而有效的治疗方法.     

输尿管镜碎石术联合体外冲击波碎石治疗较大肾盂结石疗效分析

目的：本研究旨在比较输尿管镜钬激光碎石术或气压弹道碎石术合并体外冲击波碎石术（ESWL）与单一使用ESWL两种方法处理较大肾盂结石（2～3cm）的手术效果和并发症。方法：治疗肾盂结石为2～3cm的总共42例患者。被随机分为两组,其中1组为18例,2组为24例。对l组患者首先行钬激光或气压弹道碎石治疗,并于术后置双J管,于2～4周后行ESWL。2组患者,置双J管后行ESWL。3个月后评估两组间结石清除率、并发症和总治疗费用。结果：1组患者中,6例患者（33．3％）行输尿管镜碎石术后,结石被完全击碎,无需继续ESWL处理;7例患者（38．8％）输尿管镜碎石术后需一期ESWL,2例患者（12．5％）术后需二期ESWL,结石才能被完全清除。2组患者一期ESWL成功处理结石为5例（20．8％）,二期ESWL成功处理结石为7例（29．1％）。两组结石清除率,1组明显高于2组（83．3％与50．0％,P〈O．05）。l组输尿管镜手术时间平均为27min,2组输尿管镜置输尿管导管平均用时15min。两组间均未出现严重并发症。两组平均治疗费用分别为3200元和2800元。结论：输尿管镜碎石术联合ESWL治疗肾盂较大结石是一种合理而且有效的治疗方法。     

Does further extracorporeal lithotripsy promote clearance of small residual fragments?

Small persistent fragments (less than or equal to 4 mm) following extracorporeal shock wave lithotripsy have been termed clinically insignificant residual fragments (CIRF), but their presence may be associated with an increased rate of development of recurrent symptomatic renal calculi. We have adopted a policy of further extracorporeal piezoelectric shock wave lithotripsy (EPL) for patients with CIRF in an attempt to promote complete clearance. A series of 22 patients with a mean initial stone burden of 16 mm (range 7-48) developed CIRF after a median of 2 EPL treatment sessions (range 1-9). CIRF were in the lower calices (n = 20), middle calices (n = 1) and upper calices (n = 1). These calices were normal (n = 6), slightly dilated (n = 9), moderately dilated (n = 2) or grossly dilated (n = 5). After 6 to 14 months, patients underwent a further session of EPL. One month later, 3 patients with normal calices showed a considerable reduction in CIRF, but all other patients showed no change. When CIRF form in normal calices a further session of EPL may promote clearance. However, when calices containing CIRF are significantly dilated, further EPL is of no value.     

Clinical study on recurrence of urinary tract lithiasis of ESWL

During the 4 year period from September 1, 1984 through August 31, 1988, a total of 1,866 patients with calculi of the urinary tract (125 patients had bilateral calculi) were subjected to extracorporeal shock wave lithotripsy (ESWL) with a DORNIER HM3 ESWL apparatus. Follow-up was performed factor 1,056 cases 3 or more months after complete elimination of the calculi, and data were obtained for 343 of them. Lithiasis was found to have recurred after ESWL in 30 cases, with a recurrence rate of 11.1%. Recurrence was seen in 16.9% of cases with multiple calculi and 6.5% of cases with a single calculus. The difference was statistically significant. Surgical removed of calculi or spontaneous discharge of calculi had been experienced in 50.0% of the recurrent cases and 27.8% of the non recurrent cases. The difference was also statistically significant. Stone size, stone location and urinary tract infection were unrelated to the recurrence.     

Simple Radiological Indicators for Staghorn Calculi Response to ESWL

Objective: To evaluate staghorn calculi response to ESWL using simple radiological indicators which are stone size, stone homogeneity, and stone density. Patients and methods This is a prospective study of 60 patients with staghorn calculi where the majority had ESWL. The relationship between response and size, homogeneity and density is studied. Results Single staghorn calculus less than 4 cm, heterogeneous with stone density similar to bone or a little denser than bone has best response to ESWL. Conclusion: ESWL is useful as first line therapy for staghorn calculi less than 4 cm, heterogeneous with similar density to bone or a little denser than bone.