Flexible ureterorenoscopy versus extracorporeal shock wave lithotripsy for treatment of lower pole stones of 10-20 mm

Study Type – Therapy (case series) Level of Evidence 4 What's known on the subject? and What does the study add? Shock wave lithotripsy and flexible ureterorenoscopy are acceptable treatment options for lower pole stones smaller than 10 mm, while percutaneous nephrolithotomy is the favoured treatment for stones larger than 20 mm. For treatment of lower pole stones of 10–20 mm, flexible ureterorenoscopy has a significantly higher stone‐free rate and lower retreatment rate than shock wave lithotripsy.

OBJECTIVE

• ? To compare the outcomes of flexible ureterorenoscopy (F‐URS) and extracorporeal shock wave lithotripsy (ESWL) for treatment of lower pole stones of 10–20 mm.

PATIENTS AND METHODS

• ? The database of patients with a single lower pole stone of 10–20 mm was examined to obtain two matched groups who were treated with F‐URS or ESWL. Matching criteria were stone length, side and patient gender.
• ? Stone‐free rates were evaluated 3 months after the last treatment session by non‐contrast computed tomography. Both groups were compared for retreatment rate, complications and stone‐free rate.

RESULTS

• ? The matched groups included 37 patients who underwent F‐URS and 62 patients who underwent ESWL. Retreatment rate was significantly higher for ESWL (60% vs 8%, P < 0.001).
• ? Complications were more after F‐URS (13.5% vs 4.8%), but the difference was not significant (P= 0.146). All complications were grade II or IIIa on modified Clavien classification.
• ? The stone‐free rate was significantly better after F‐URS (86.5% vs 67.7%, P= 0.038). One failure of F‐URS (2.7%) and five failures (8%) of ESWL were treated with percutaneous nephrolithotomy.
• ? Significant residual fragments in three patients (8%) after F‐URS were treated with ESWL, while significant residual fragments after ESWL in five patients (8%) were treated with F‐URS. Residual fragments (<4 mm) were followed every 3 months in one patient (2.7%) after F‐URS and in 10 patients (16%) after ESWL.

CONCLUSIONS

• ? For treatment of lower pole stones of 10–20 mm, F‐URS provided significantly higher stone‐free rate and lower retreatment rate compared with ESWL.
• ? The incidence of complications after F‐URS was not significantly more than after ESWL.

     

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.     

Improved cost‐effectiveness and efficiency with a slower shockwave delivery rate

Study Type – Therapy (case series)
Level of Evidence 4

OBJECTIVE

To determine the benefits of a slower shockwave (SW) delivery rate of 70 shocks/min on the treatment efficiency and cost‐effectiveness of extracorporeal SW lithotripsy (ESWL).

PATIENTS AND METHODS

Patients who had ESWL for their upper urinary tract radio‐opaque calculi were categorized into two groups: slow (70 SW/min) and fast (100 SW/min) delivery rate. All treatment was carried out using a lithotripter (Model S, Dornier MedTech, Wessling, Germany) as an outpatient procedure with no anaesthesia or sedation. The groups were followed for ≥6 months. The primary outcomes compared were the stone‐free rate, re‐treatment rate, additional procedure rate, perceived cost and actual cost. Clinical success was defined as stone‐free status or asymptomatic insignificant residual fragments of <3 mm. Perceived cost was defined as the cost of ESWL alone, and actual cost included the cost of additional procedures and overhead costs to result in clinical success.

RESULTS

In all, the study included 102 patients, categorized into the fast (51) and slow (51) rate groups. The groups were comparable in terms of sex, age, body mass index, stone size and stone location. The slow group had a significantly better stone‐free rate (67% vs 25.5%, P = 0.002, chi‐square), fewer mean shocks to clinical success (3045 vs 4414, P < 0.001, U‐test), lower re‐treatment rate (22% vs 45%P = 0.013, chi ‐square), a lower additional procedure rate (12% vs 29%, P = 0.02, chi‐square), greater efficiency quotient (0.51 vs 0.16) than the fast group. The mean perceived cost of ESWL (GB£ 297 vs £394, P = 0.013, U‐test) and the mean actual cost of the slow group were significantly less (£496 vs £1002, P = 0.001, U‐test).

CONCLUSION

Slowing the SW delivery rate to 70/min significantly reduced the actual cost by half and improved treatment efficiency.     

Ureteric stents compromise stone clearance after shockwave lithotripsy for ureteric stones: results of a matched-pair analysis

OBJECTIVE

To identify the effect of the presence of a ureteric stent on the outcome of extracorporeal shockwave lithotripsy (ESWL), by comparing patients with ureteric stones with matched‐pair analysis.

PATIENTS AND METHODS

Patients undergoing ESWL with the Sonolith Vision lithotripter (Technomed Medical Systems, Vaulx‐en‐Velin, France) were identified from our prospectively maintained database. Only adult patients with a solitary, radio‐opaque, previously untreated ureteric stone were considered for further analysis. A follow‐up of ≥3 months with a plain abdominal film was used to identify residual fragments. Patients were exactly matched for gender, side, location in the ureter and size (in two dimensions, within ±2 mm). If both diameters could not be matched exactly, the size was extended to ±1 mm and then to ±2 mm of both diameters. An effort was finally made to match patients by age. The treatment outcome in terms of stone‐free rates was assessed and compared using McNemar’s test.

RESULTS

In all, 45 patients with a ureteric stent in place during ESWL were identified. The only patient who could not be adequately matched was a 40‐year‐old man with an 8 × 3 mm stone in the upper ureter. The best/closest match for age was selected. Most stones were in the upper ureter (77%); the mean stone size was 8.5 and 8.6 mm, respectively, with no statistical differences between the groups for age and size of stones (P = 0.41 and 0.86, Student’s t‐test). In 12 pairs, only patients with no stent were stone‐free, compared to two pairs where the patient with a stent was stone‐free. Using McNemar’s test, the odds ratio was 6.0 (95% confidence interval 1.3–55.2) and the difference between the groups was statistically significant (P = 0.016).

CONCLUSION

These results show that the presence of a stent is associated with a worse outcome after ESWL for ureteric stones. Ureteric stents should still be used in cases of obstruction, when there is a risk of sepsis, and in patients with intolerable pain or deteriorating renal function. However, their use in patients offered ESWL for ureteric stones should be considered with caution.     

A prospective randomized trial comparing 2 lithotriptors for stone disintegration and induced renal trauma

PURPOSE: We compare the efficacy and resulting kidney trauma of the HM3 (Dornier Medical Systems, Inc., Marietta, Georgia) and Lithostar Plus (Siemens, Issaquah, Washington) lithotriptors in a prospective randomized trial treating calix and renal pelvis stones. MATERIALS AND METHODS: Patients with a solitary renal pelvic stone 2 cm. or less in diameter or a solitary calix stone 1 cm. or less in diameter were randomized for treatment with the HM3 or Lithostar Plus. Stone disintegration and dilatation of the pyelocaliceal system were evaluated by abdominal plain x-ray and renal ultrasound 1 day and 3 months after treatment. Kidney trauma was determined by measurement of N-acetyl-beta-glucosaminidase and beta-galactosidase (NAG) in pretreatment urine and 4, 12-hour urine samples collected within the first 2 days after extracorporeal shock wave lithotripsy (ESWL, Dornier Medical Systems, Inc.). RESULTS: Of 167 patients with 176 stones 91 were randomized to the HM3 and 85 to the Lithostar Plus lithotriptor group. The preoperative stone burden was comparable in both groups. On postoperative day 1 patients treated with the HM3 or Lithostar Plus were stone-free or had fragments 2 mm. or less (91% and 65%, p <0.001), 3 to 5 mm. (8% and 25%, p = 0.003) and 6 mm. or greater (1% and 10%, p = 0.008), respectively. Patients treated with the HM3 had less posttreatment dilatation of the collecting system (p = 0.01). Obstructive pyelonephritis occurred in 1% of the HM3 and 8% of the Lithostar Plus group (p = 0.02). Re-treatment rate was 4% in the HM3 and 13% in the Lithostar Plus group (p = 0.05). Mean excretion of urinary NAG per treatment (including re-treatments) was comparable in both groups but NAG excretion in relation to stone volume and shock wave number 12 to 24 hours after ESWL was significantly higher in the HM3 group (p <0.05). At 3-months postoperatively 89% of the patients treated with the HM3 and 87% treated with the Lithostar plus were stone-free with no dilatation of the collecting system. CONCLUSIONS: This prospectively randomized study indicated that the HM3 is still the gold standard in regard to disintegration of pelvicaliceal stones. Stone disintegration with the HM3 is better with fewer shock waves, re-treatment rate is lower, and posttreatment dilatation of the collecting system and complications such as obstructive pyelonephritis are less than those with the Lithostar Plus. ESWL induced kidney trauma is minor and resolves within 2 days. The HM3 delivers more energy per shock wave into the kidney as assessed by urinary NAG.     

Low‐frequency extracorporeal shock wave lithotripsy improves renal pelvic stone disintegration in a pig model

OBJECTIVE

To compare disintegration rates for renal stones treated by 60 vs 120 shock waves (SW)/min at the same energy settings, using standardized validated artificial stones in a pig model.

MATERIALS AND METHODS

Gypsum artificial stones (13 × 6 mm) were inserted into the renal pelvis on either side of 12 anaesthetized pigs by open surgery. Extracorporeal SW lithotripsy (ESWL) was applied using a new electromagnetic lithotripter (Lithoskop®, Siemens AG Healthcare, Munich, Germany) at 60 and 120 SW/min; 3000 SW were applied to each kidney with the same energy settings. Stone fragments were collected after nephrectomy, passed through calibrated test sieves, and weighed. Fragment size categories were stratified according to the sieve hole size as set by the manufacturer. Fragments of ≤4.75 mm were defined as capable of spontaneous passage. For each pig the number of stone fragments of the respective size categories was counted and weighed. The results were analysed statistically using the Mann–Whitney U‐test.

RESULTS

For fragments of >4.75 mm, the median (range) fragment counts were 0 (0–1) for 60 and 1 (0–3) for 120 SW/min (P = 0.006). For small fragments of 2.0–2.8 mm, the median fragment counts were 15 (4–24) for 60 and 10 (2–25) for 120 SW/min (P = 0.033); for fragments of 1.0–2.0 mm the respective values were 42.5 (9–81) and 21.5 (6–56) (P = 0.004). Of the total stone fragment mass in the 60 and 120 SW/min groups, 4.34% and 31.31% were >4.75 mm. There was complete disintegration yielding fragments capable of spontaneous passage in 10 of 12 renal units at 60 and in three of 12 renal units at 120 SW/min. The mean treatment time was 55.4 min for therapy at 60 and 34.3 min for therapy at 120 SW/min (P = 0.001). One parenchymal haematoma of 15 × 10 mm developed in the 60 SW/min group and another of 20 × 10 mm developed in the 120 SW/min group.

CONCLUSION

ESWL fragmentation with equal energy application yields significantly smaller fragments at 60 than at 120 SW/min. The theoretical stone passage rate could therefore be ≈80% for 60 vs 25% for 120 SW/min ESWL. Renal haematoma formation was comparable in both groups.     

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.     

Audit on extracorporeal shockwave lithotripsy of renal and ureteric stones in Tuen Mun Hospital using Dornier Lithotripter S

Objectives: We report our results of an audit on extracorporeal shockwave lithotripsy (ESWL) of renal and ureteric stones using the Dornier Lithotripter S (Dornier MedTech, Wessling, Germany). Materials and Methods: We retrospectively reviewed the outcome of ESWL for patients treated between March and December 2003 (pilot). Prospective collection of data was performed for patients treated between October 2004 and March 2005 (re‐audit) after an upgrade to the power unit of our shockwave emitter by the manufacturer in September 2004. Patient demographic data, target stone characteristics and treatment outcome were recorded. Analysis of the results between the two periods was made. Results: ESWL was performed on 232 and 220 target stones in the pilot and re‐audit periods, respectively. Patient demographic data and stone characteristics were similar between the two periods. Clinical success (stone fragments less than 4 mm in size after one session of ESWL) was achieved in 31% and 61% (stone‐free 19% and 38%) of patients in the pilot and re‐audit periods, respectively (P < 0.0001, χ² test). Patients requiring re‐treatment with ESWL to achieve success and auxiliary procedure reduced to 8% and 5%, respectively, in the re‐audit period (pilot: 14% and 14%, respectively). The overall complication rate was reduced from 6.2% (pilot) to 3.3% (re‐audit). Obstructive complications significantly reduced from 4.8% to 0.5% (pilot vs re‐audit, Fisher’s exact test, P = 0.012). Conclusion: Effectiveness of our lithotripter was significantly improved and obstructive complications were significantly reduced after an upgrade to the power unit of the electromagnetic shockwave emitter of our lithotripter.     

Treatment of renal stones in infants: comparing extracorporeal shock wave lithotripsy and mini-percutaneous nephrolithotomy

The objective of the study is to compare the efficacy and safety of extracorporeal shock wave lithotripsy (ESWL) and mini-percutaneous nephrolithotomy (MPCNL) in treating renal stones sizing 15–25 mm in infants <3 years. Forty-six infants with renal stones sizing 15–30 mm were treated by either ESWL (22 renal units in 22 infants) using Dornier compact delta lithotripter or MPCNL (25 renal units in 24 infants) using 14F–18F renal access under general anesthesia. The operation time, stone-free rate, re-treatment rate, and complications between the two groups were compared with the χ², Mann–Whitney U, and Student’s t tests. No significant differences in mean age and stone size were observed between the two groups. The 1- and 3-month postoperative stone-free rates were 84 and 96 % in MPCNL group and were 31.8 and 86.4 % in ESWL group. The re-treatment and complication rates were significantly higher in ESWL group than in MPCNL group (50 vs. 12 %, P = 0.004; 16.0 vs. 45.5 %, P = 0.028). The stone recurrence rate was similar between the two groups. No significant changes of serum creatinine (Cr) level and glomerular filtration rate were observed in both groups. In conclusion, MPCNL is an effective and feasible alternative monotherapy for large renal stones (15–25 mm) in infants, with a higher stone-free rate and a lower complication rate when compared with ESWL.     

A prospective randomised trial comparing the modified HM3 with the MODULITH® SLX-F2 lithotripter

Background

The relative efficacy of first- versus last-generation lithotripters is unknown.

Objectives

To compare the clinical effectiveness and complications of the modified Dornier HM3 lithotripter (Dornier MedTech, Wessling, Germany) to the MODULITH^® SLX-F2 lithotripter (Storz Medical AG, Tägerwilen, Switzerland) for extracorporeal shock wave lithotripsy (ESWL).

Design, setting and participants

We conducted a prospective, randomised, single-institution trial that included elective and emergency patients.

Interventions

Shock wave treatments were performed under anaesthesia.

Measurements

Stone disintegration, residual fragments, collecting system dilatation, colic pain, and possible kidney haematoma were evaluated 1 d and 3 mo after ESWL. Complications, ESWL retreatments, and adjuvant procedures were documented.

Results and limitations

Patients treated with the HM3 lithotripter (n = 405) required fewer shock waves and shorter fluoroscopy times than patients treated with the MODULITH^® SLX-F2 lithotripter (n = 415). For solitary kidney stones, the HM3 lithotripter produced a slightly higher stone-free rate (p = 0.06) on day 1; stone-free rates were not significantly different at 3 mo (HM3: 74% vs MODULITH^® SLX-F2: 67%; p = 0.36). For solitary ureteral stones, the stone-free rate was higher at 3 mo with the HM3 lithotripter (HM3: 90% vs MODULITH^® SLX-F2: 81%; p = 0.05). For solitary lower calyx stones, stone-free rates were equal at 3 mo (63%). In patients with multiple stones, the HM3 lithotripter's stone-free rate was higher at 3 mo (HM3: 64% vs MODULITH^® SLX-F2: 44%; p = 0.003). Overall, HM3 lithotripter led to fewer secondary treatments (HM3: 11% vs MODULITH^® SLX-F2: 19%; p = 0.001) and fewer kidney haematomas (HM3: 1% vs. MODULITH^® SLX-F2: 3%; p = 0.02).

Conclusions

The modified HM3 lithotripter required fewer shock waves and shorter fluoroscopy times, showed higher stone-free rates for solitary ureteral stones and multiple stones, and led to fewer kidney haematomas and fewer secondary treatments than the MODULITH^® SLX-F2 lithotripter. In patients with a solitary kidney and solitary lower calyx stones, results were comparable for both lithotripters.     

Extracorporeal shock wave lithotripsy using Dornier modified HM3 lithotripter comparison with the results by Dornier HM3 lithotripter

Ninety-four kidneys with renal stones less than or equal to 20 mm in diameter were treated by extracorporeal shock wave litotripsy (ESWL) using a Dornier modified HM3 lithotripter and the results were compared with those of 98 kidneys with similar size stones treated with a Dornier HM3 lithotripter. The Dornier modified HM3 lithotripter is equipped with a new type of shock wave generator with a reduced capacity for 30% less pressure peakes at the same voltage. It has an enlarged ellipsoid leading to a smaller focus and a reduced pressure per area at the shock wave entry into the skin. All treatments of modified HM3 litotripter series were performed under only intravenous analgosedation, without epidural anesthesia. The number of shock waves in the modified HM3 series ranged 900 to 6000, with the mean values of 2863 +/- 1234, which was 1.55 times as that in the Dornier HM3 series. Complete disintegration was achieved in 94 of 94 modified HM3 series kidneys and 98 of 98 kidneys of HM3 series. Complete removal of the stone was done at 72.6% in the modified HM3 series and at 70.4% in the HM3 series 3 months after ESWL. There were no severe complications in both modified HM3 series and HM3 series. Renal damage caused by ESWL was monitored by the level of urinary enzyme, N-acetyl-beta-glucosaminidase (NAG) and beta 2 microglobulin (beta 2MG) and the level of urinary protein. The levels of NAG, beta 2MG and urinary protein in the HM3 series were higher than those of the modified HM3 series.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of intracalyceal distribution on the clearance of renal stones of > or = 20 mm in children after extracorporeal lithotripsy

OBJECTIVES: To determine the effect of the intracalyceal distribution of renal stones on clearance rates after treating paediatric nephrolithiasis with extracorporeal shock wave lithotripsy (ESWL). PATIENTS AND METHODS: We assessed a retrospective case series of children (aged < or = 14 years) undergoing lithotripsy on an MPL 9000 (Dornier GmbH, Germany) echo-guided lithotripter. Patients were identified using an international coding and indexing system and ESWL registry. In all, 125 children were treated during 1990-2003, but 21 had stones of > or = 20 mm. Stone clearance was assessed at 1 and 3 months, the stone-free state being defined as no radiological evidence of stone or fragments of < or = 3 mm. Failed treatments were analysed to identify any correlation with stone site. RESULTS: The overall stone-free rate was 81%; in four children the treatment failed (all girls) and subsequently they required ancillary procedures. Nineteen patients (90%) received up to three sessions of ESWL; two required four or more sessions. Of the four children in whom treatment failed, two had JJ stents; the stones were in the lower pole calyx in two, and the renal pelvis and lower pole calyx in two. The mean stone size in those where treatment failed was 25 mm, vs 21 mm in the stone-free group. The complication rate was 19%, but only one child required admission to hospital. CONCLUSIONS: ESWL is very effective for renal stones in children, with minimal morbidity. Lower pole and partial staghorn stones with a major component in the lower pole calyx should preferably be treated by a percutaneous approach.     

Extracorporeal shockwave lithotripsy vs ureteroscopy as first‐line therapy for patients with single,distal ureteric stones: a prospective randomized study

Study Type – Therapy (RCT)
Level of Evidence 1b

OBJECTIVE

To compare extracorporeal shockwave lithotripsy (ESWL) and ureteroscopy (URS) as first‐line treatments for patients with distal ureteric stones.

PATIENTS AND METHODS

In all, 273 patients with single, monolateral, radiopaque, distal ureteric stones of 0.5–1.5 cm were enrolled in a prospective randomized trial. Patients were randomized to undergo ESWL (137) or URS (136). The electromagnetic Modulith SLX lithotripter (Storz Medical, Switzerland) was used for ESWL and a semi‐rigid ureteroscope was used for URS. Patients in both groups were compared for overall stone‐free rates (SFRs), re‐treatment rates, need for auxiliary procedures and complication rates. A subgroup analysis was performed in both groups according to stone size of ≤1 cm and >1 cm.

RESULTS

Patients in the ESWL group achieved a 92.70% overall SFR with a 44.88% re‐treatment rate and an 11.02% auxiliary procedure rate. Complications occurred in 15.32% of patients treated with ESWL. Patients in the URS group achieved a 94.85% overall SFR with a re‐treatment rate of 7.75% and an auxiliary procedure rate of 18.60%. Complications occurred in 19.11% of patients treated with URS. In the ESWL group, the need for re‐treatments and for auxiliary procedures as well as the incidence of complications was significantly higher in patients with stones of >1 cm. In patients with stones of ≤1 cm treated with ESWL the need for re‐treatments and for auxiliary procedures as well as the incidence of complications was significantly lower than for those treated with URS.

CONCLUSION

In centres where both techniques are available, ESWL should be the preferred treatment for patients with single distal ureteric stones of ≤1 cm and URS should be reserved for patients with stones of >1 cm.     

A randomized clinical trial of suspension technique for improving early recovery of urinary continence after radical retropubic prostatectomy

OBJECTIVE

To evaluate, in a prospective, single‐blind, randomized trial, the safety and efficacy of a suspension technique for improving early recovery of continence after radical retropubic prostatectomy (RRP).

PATIENTS AND METHODS

We randomly assigned 60 men with clinically localized prostate cancer to RRP; 30 were treated with the suspension technique and the remaining 30 were not. All patients had RRP by the same surgeon followed by early catheter removal on the third day after RRP. The primary outcome measures were the interval to recovery of continence, and the positive margin rates. The continence status was evaluated by a third party using validated questionnaires at baseline before RRP and at 4 and 7 days, and 2 weeks, 1, 3, 6 and 12 months after RRP.

RESULTS

The suspension technique resulted in significantly greater continence rates at 1, 3 and 6 months after RRP of 53% vs 20%, 73% vs 47% and 100% vs 83%. Kaplan‐Meier curves also showed that patients in the suspension group had a significantly earlier recovery of continence than in the no‐suspension group; the median (95% confidence interval) interval for recovery was 31 (12–74) days in the suspension group and 90 (65–150) days in the no‐suspension group (log rank test, P = 0.002). The groups had no significant differences in their histological status.

CONCLUSIONS

The suspension technique had a significant effect on the earlier recovery of urinary continence within 6 months after RRP, without compromising the oncological outcome of RRP.     

Extracorporeal shock-wave lithotripsy monotherapy in renal pelvic ectopia

Objectives

To determine the efficacy of extracorporeal shock-wave lithotripsy (ESWL) in the treatment of urinary stones in pelvic kidneys.

Methods

Fourteen male patients with renal pelvic ectopia and stones were treated with ESWL monotherapy using the unmodified Dornier HM3 lithotriptor with its original generator and ellipsoid. Twelve patients were treated in the prone position using cystoscopically placed ureteral catheters to aid in fluoroscopic localization, whereas 2 patients were treated in the supine position. A review of their stone disease, ESWL treatment, ancillary procedures, outcome, and complications is presented.

Results

All pelvic kidneys were free of infection and obstruction in this group. The mean stone burden was 30.2 ± 37.8. Most patients required a single session (9 of the 14 [64%]), 2 patients required two sessions, and 2 patients required multiple sessions. The average number of shock waves per session was 1689 (range 450 to 3500), with average kilovoltage of 21.5 (range 18 to 24). Eighty-two percent of the patients followed (9 of 11 ) were stone-free at 3 months. No ancillary endourologic procedures were required to deal with the presenting stones. Obstructive steinstrasse complicated treatment in only 2 patients (14%) and was successfully treated by further ESWL in both patients; in 1 of them, ureteroscopy was needed.

Conclusions

ESWL monotherapy of renal pelvic ectopia stones is very effective and should be considered as the first therapeutic option for these patients, provided that accurate localization of the stone treated and proper positioning of patients that ensures adequate delivery of shock-wave energy can be maintained.     

Comparison of efficacy and safety of ESWL in paediatric and adolescent versus adult urolithiasis: A single center 5-year experience from a tertiary care hospital

Objective

To retrospectively compare the efficacy and safety of extra-corporeal shock wave lithotripsy (ESWL) for renal/upper ureteric calculi in pediatric/adolescents (group 1) vs adults(group 2).

Extracorporeal shock wave lithotripsy in children: equivalent clearance rates to adults is achieved with fewer and lower energy shock waves

OBJECTIVE

To compare the outcome, safety and efficiency of extracorporeal shock wave lithotripsy (ESWL) using an electromagnetic lithotripter for upper urinary tract stones in children and adults.

PATIENTS AND METHODS

We retrospectively reviewed data over a 5‐year period for patients with solitary, renal and upper ureteric stones measuring <2 cm in whom ESWL was the treatment method. Group A consisted of 44 children (mean [sd ] age 5.9 [4.4] years) and group B of 562 adults (mean [sd ] age 40.9 [13.1] years). The number and energy of SWs used was not predetermined and was tailored until adequate fragmentation was achieved. Initial stone reassessment was performed at 48 h and monthly thereafter. The number of SWs, intensity of SWs, stone‐free rate, auxiliary procedure rate, re‐treatment rate, complication rate and effectiveness quotient (EQ) were assessed in each group.

RESULTS

The stone‐free rate with ESWL was 84% in children and 87% in adults (P = 0.78). The EQ was 77% and 75% in children and adults, respectively (P = 0.56). The mean (sd ) number of SWs and energy required per session was 950 (349) and 11.83 (0.48) kV in children and 1262 (454) and 12.36 (0.34) kV in adults (P < 0.001). The re‐treatment, auxiliary procedure and complication rates were similar in both groups.

CONCLUSION

ESWL is as safe and effective in children as in adults for solitary renal and upper ureteric stones that are <2 cm. Children required significantly fewer and lower energy SWs to achieve equivalent results.     

New Stone Formation: A Comparison of Extracorporeal Shock Wave Lithotripsy and Percutaneous Nephrolithotomy

Purpose

There is theoretical concern that stone recurrence rates may be higher following extracorporeal shock wave lithotripsy (ESWL*) compared to other techniques because of residual stone debris.*Dornier Medical Systems, Inc., Marietta, Georgia.

Materials and Methods

We documented all new stone formations in 298 consecutive patients who initially achieved a stone-free status following ESWL for renal calculi less than 2 cm. in largest dimension, and compared the findings to those of 62 patients treated with percutaneous nephrolithotomy without ultrasonic fragmentation. Stone-free status was assessed by a centrally reviewed plain abdominal film and renal tomograms at 3 months. A plain abdominal film was repeated at 12 and 24 months to detect recurrence.

Results

New stones formed in 22.2 percent of patients after ESWL and 4.2 percent after percutaneous nephrolithotomy at 1 year (p = 0.004), and in 34.8 percent versus 22.6 percent, respectively, at 2 years (p = 0.190). Furthermore, more new stones recurred in the lower and mid calices compared to baseline location in the ESWL group (chi-square less than 0.0001), which was not observed in the percutaneous nephrolithotomy group.

Conclusions

Our data support a trend toward higher stone recurrence rates in ESWL treated patients, which may be due to microscopic sand particles migrating to dependent calices and acting as a nidus for new stone formation.     

Chronic kidney disease affects the stone‐free rate after extracorporeal shock wave lithotripsy for proximal ureteric stones

Study Type – Therapy (case series)
Level of Evidence 4

OBJECTIVE

To investigate the effect of renal function on the stone‐free rate (SFR) of proximal ureteric stones (PUS) after extracorporeal shock wave lithotripsy (ESWL), as urinary obstruction caused by PUS can impair renal function, and elevated serum creatinine levels are associated with decreased ureteric stone passage.

PATIENTS AND METHODS

From January 2005 to December 2007, 1534 patients had ESWL for urolithiasis, 319 having ESWL in situ for PUS; they were reviewed retrospectively. Patients requiring simultaneous treatment of kidney stones, placement of a double pigtail stent, or percutaneous pigtail nephrostomy tube were excluded. We divided patients into groups by chronic kidney disease (CKD) stage according to the estimated glomerular filtration rate (eGFR) of ≥60 and <60 mL/min/1.73 m². Stone‐free status was defined as no visible stone fragments on a plain abdominal film at 3 months after ESWL. A logistic regression model was used to evaluate the possible significant factors that influenced the SFR of PUS after ESWL, and to develop a prediction model.

RESULTS

The overall SFR of PUS (276/319 patients) was 86.5%; the SFR was 93% in patients with an eGFR of ≥60 and 50% in those with an eGFR of <60 (P < 0.001). After univariate and multivariate analysis, the three significant factors affecting SFR were an eGFR of ≥60, stone width, and gender, with odds ratios (95% confidence intervals) of 19.54 (8.25–46.30) (P < 0.001), 0.67 (0.55–0.82) (P < 0.001) and 0.16 (0.05–0.50 (P = 0.002), respectively. A logistic regression model was developed to estimate the probability of SFR after ESWL, the equation being 1/(1 + exp [?(3.8137 ? 0.3967 × (stone width) + 2.9724 × eGFR ? 1.8120 × Male)]), where stone width is the observed value (mm), eGFR = 1 for eGFR ≥60 and 0 for <60, and male = 1 for male, 0 for female.

CONCLUSIONS

Gender, eGFR ≥60 and a stone width of >7 mm were significant predictors affecting the SFR after one session of ESWL for PUS.     

Independent assessment of a wide-focus, low-pressure electromagnetic lithotripter: absence of renal bioeffects in the pig

OBJECTIVE

To assess the renal injury response in a pig model treated with a clinical dose of shock waves (SWs) delivered at a slow rate (27 SW/min) using a novel wide focal zone (18 mm), low acoustic pressure (<20 MPa) electromagnetic lithotripter (Xi Xin‐Eisenmenger, XX‐ES; Xi Xin Medical Instruments Co. Ltd., Suzhou, PRC).

MATERIALS AND METHODS

The left kidneys of anaesthetized female pigs were treated with 1500 SWs from either an unmodified electrohydraulic lithotripter (HM3, Dornier MedTech America, Inc., Kennesaw, GA, USA; 18 kV, 30 SW/min) or the XX‐ES (9.3 kV, 27 SW/min). Measures of renal function (glomerular filtration rate, GFR, and renal plasma flow) were collected before and after SW lithotripsy, and kidneys were harvested for histological quantification of vascular haemorrhage, expressed as a percentage of the functional renal volume (FRV). A fibre‐optic probe hydrophone was used to characterize the acoustic field, and the breakage of gypsum model stones was used to compare the function of the two lithotripters.

RESULTS

Kidneys treated with the XX‐ES showed no significant change in renal haemodynamic function and no detectable tissue injury. Pigs treated with the HM3 had a modest decline from baseline (≈ 20%) in both GFR (P > 0.05) and renal plasma flow (P = 0.064) in the treated kidney, but that was not significantly different from the control group. Although most HM3‐treated pigs showed no evidence of renal tissue injury, two had focal injury measuring 0.1% FRV, localized to the renal papillae. The width of the focal zone for the XX‐ES was ≈ 18 mm and that of the HM3 ≈ 8 mm. Peak positive pressures at settings used to treat pigs and break model stones were considerably lower for the XX‐ES (17 MPa at 9.3 kV) than for the HM3 (37 MPa at 18 kV). The XX‐ES required fewer SWs to break stones to completion than did the HM3, with a mean (sd ) of 634 (42) and 831 (43) SWs, respectively (P < 0.01). However, conditions were different for these tests because of differences in physical configuration of the two machines.

CONCLUSION

The absence of renal injury with the wide focal zone XX‐ES lithotripter operated at low shock pressure and a slow SW rate suggests that this lithotripter would be safe when used at the settings recommended for patient treatment. That the injury was also minimal using the Dornier HM3 lithotripter at a slow SW rate implies that the reduced tissue injury seen with these two machines was because they were operated at a slow SW rate. As recent studies have shown stone breakage to be improved when the focal zone is wider than the stone, a wide focal zone lithotripter operated at low pressure and slow rate has the features necessary to provide better stone breakage with less tissue injury.