Mini-Percutaneous Nephrolithotomy vs Extracorporeal Shock Wave Lithotripsy for Management of Renal Stones in Pediatric Age Group Less Than 6 Years with Renal Stones Less Than 20 mm. A Prospective, Randomized Trial.

Our aim was to compare transureteral lithotripsy (TUL) and extracorporeal shock wave lithotripsy (SWL) in the management of upper ureteral calculi larger than 5 mm in diameter. Patients who had upper ureteral calculi greater than 5 mm in diameter were enrolled in this clinical trial. The calculi had not responded to conservative or symptomatic therapy. Semirigid ureteroscopy and pneumatic lithotripsy were used for TUL in 52 patients and SWL was performed in 48. Analysis of the calculi compositions was done and the patients were followed up by plain abdominal radiography and ultrasonography 3 month postoperatively. The stone-free rates were 76.9% in the patients of the TUL group and 68.8% in the patients of the SWL group. These rates in the patients with mild or no hydronephrosis were 85.7% and 59.1% for the SWL and TUL groups, respectively. In the TUL group, half of the patients with no hydronephrosis developed upward calculus migration. The stone-free rates were 75.0% and 89.3% for the patients with moderate hydronephrosis and 70.0% and 100.0% for those with severe hydronephrosis in the SWL and TUL groups, respectively. All of the failed cases were treated by double-J stenting and TUL or SWL successfully. There were no serious complications. Upward calculus migration after TUL was more frequent in cases with no hydronephrosis or mild hydronephrosis (41.0%). Upper ureteral calculi smaller than 1 cm can be safely and effectively managed using semirigid ureteroscopy and pneumatic lithotripsy. However, the SWL approach has still its role if an experienced endourologist is not available.

A Clinical Nomogram to Predict the Successful Shock Wave Lithotripsy of Renal and Ureteral Calculi

Objectives: To compare the efficacy, complications, and costs of percutaneous nephrolithotomy (PNL) and extracorporeal shock wave lithotripsy (SWL) in the treatment of a 20 to 30 mm single renal pelvic stone with a density ≤1000 HU. Patients and Methods: Eighty patients were prospectively randomized to receive either PNL or SWL during May 2017 to April 2019. The relevant demographic and clinical characteristics were compared. Results: The mean age in the PNL and SWL groups was 43.25 ± 15.16 and 44.18 ± 12.08 years, respectively. The mean stone sizes were 25.2 ± 3.9 and 24.6 ± 2.3 mm, respectively. The stone-free rate (SFR) was significantly different after the primary procedures (92.5% vs 37.5%, respectively; p < 0.04), but it was comparable after 3 months (97.5% vs 90%, respectively; p = 0.723), with a higher rate of auxiliary procedures after SWL (p = 0.017). On multivariate analysis, stone density was the only significant variable for the SFR in the SWL group (p = 0.004). Complications occurred in 27.5% and 22.5% of cases, respectively (p = 0.796). The mean costs of SWL (650.23 ± 424.74 United States Dollars [US$]) were significantly lower than those of PNL (1137.65 ± 224.43 US$; p < 0.0001). Conclusions: The SFRs for PNL and SWL were not significantly different after 3 months in the treatment of a 20 to 30 mm single renal pelvic stone with ≤1000 HU, although PNL provided a significantly higher rate after its primary procedure. SWL was significantly less costly, but it mandated a significantly higher number of auxiliary procedures than PNL.

PROSPECTIVE RANDOMIZED TRIAL COMPARING SHOCK WAVE LITHOTRIPSY AND URETEROSCOPY FOR MANAGEMENT OF DISTAL URETERAL CALCULI

Endourological Management of Pediatric Stone Disease: Present Status

Diabetes Mellitus and Hypertension Associated With Shock Wave Lithotripsy of Renal and Proximal Ureteral Stones at 19 Years of Followup

To compare the stone clearance times in patients undergoing extracorporeal shock wave lithotripsy (SWL) or retrograde intrarenal surgery (RIRS) for single radiopaque renal pelvis stones 10-20 mm in size. The results of this study may guide urologists and patients and aid in selecting the optimal preoperative treatment. Between January 2013 and February 2015, we conducted a retrospective study and collected data from 333 patients treated with SWL (n = 172) or RIRS (n = 161). We included successfully treated patients with a single radiopaque renal pelvis stone 10-20 mm in size to calculate stone clearance times. The average stone size for the SWL group was 14.62 &plusmn; 2.58 mm and 14.91 &plusmn; 2.92 mm for the RIRS group. The mean Hounsfield unit (HU) of the patients was 585.40 &plusmn; 158.39 HU in the SWL group and 567.74 &plusmn; 186.85 HU in the RIRS group. Following full fragmentation, the mean stone clearance time was 26.55 &plusmn; 9.71 days in the SWL group and 11.59 &plusmn; 7.01 days in the RIRS group (P &lt; .001). One of the most overlooked parameters in urinary stone treatments is stone clearance. We believe this study will shed light for those who aim to conduct larger randomized prospective studies.&nbsp.

Effect of Escalating Versus Fixed Voltage Treatment on Stone Comminution and Renal Injury During Extracorporeal Shock Wave Lithotripsy: A Prospective Randomized Trial

Background: The purpose of this study is to compare the efficacy and safety of extracorporeal shockwave lithotripsy (SWL), retrograde intrarenal surgery (RIRS), mini-percutaneous nephrolithotomy (mPNL), and standard-percutaneous nephrolithotomy (stPNL) for the treatment of 20-30 mm kidney stones. Methods: The records of 1197 patients (SWL = 149, RIRS = 205, mPNL = 525, and stPNL = 318) from 8 centers were reviewed retrospectively. Four procedures were compared for stone-free rates (SFRs), auxiliary treatment, and associated complications. Results: Initial SFRs were 43.6%, 54.6%, 86.7%, and 87.7% in SWL, RIRS, mPNL, and stPNL, respectively (P < .001), whereas the final SFRs were 71.8%, 80%, 90.5%, and 89.6% (P < .001). The rate of auxiliary treatment in the groups was 38.3%, 26.8%, 5%, and 4.4%, respectively (P < .001). The initial and final SFRs in the mPNL and stPNL groups were higher than those in SWL and RIRS groups (P < .001). The rate for auxiliary treatment was lower in the mPNL and stPNL groups (P < .001). The operation time was longer in the RIRS group (P = .005). According to the Clavien-Dindo classification, the complication rate in the SWL group was lower than that in the surgical approaches (P < .001); however, no statistical difference was detected between RIRS, mPNL, and stPNL groups. mPNL and stPNL had a higher success rate than RIRS or SWL for treating 20-30 mm kidney stones. Conclusion: In the treatment of 2-3 cm renal stones, RIRS and PNL were more effective than SWL to obtain a better SFR and less auxiliary treatment rate. Compared with RIRS, mPNL and stPNL provided a higher SFR with similar complication rates.

Introduction and objectivesDespite being uncommon, infantile kidney stone remains a major health problem due to its higher recurrence rate and morbidity. The parents usually notice that their infants have recurrent fever and failure to thrive of unknown origin. Those patients comprise a big challenge for the urologist in management. Therefore, this study aimed to evaluate the outcome of shockwave lithotripsy (SWL) in management of renal stones in infants. Subjects and methodsA retrospective analysis of prospectively collected data performed between January 2009 and December 2012 for infants underwent SWL for single radio-opaque renal stones ≤15mm at a single stone center. SWL was performed with Dorneir S lithotripter with a maximum of 1500 shocks per session. A single session was indicated for each infant, but a second session was performed when satisfactory disintegration was not achieved. Follow-up based on urinalysis, urine culture and sensitivity, plain X-ray kidney ureter bladder (KUB) and abdominal ultrasonography (US) was carried out 2 weeks post SWL and monthly for 3 successive months. Multislice Computed tomography (MSCT) was performed 3-months post-SWL to confirm the stone-free status. ResultsA total of 87 infants, less than 24 months of age were enrolled in this research. SWL success was defined as absence of any residual fragments on MSCT 3-months after the last session. Stone free rate was 93.1% after the first SWL session and reached 100% after the second session. Rate of retreatment with second session of SWL was 6.9%. Urinary tract infection (UTI) was detected in 10.3%, transient renal obstruction with low grade fever in 4.6% of infants and no major complication had been recorded. ConclusionThe new generation of SWL technology with a precise focal area seems to be safe and effective in management of kidney calculi in infants.

We aimed to compare the outcomes of microperc and shockwave lithotripsy (SWL) for treatment of kidney stones in children. The medical records of 145 patients under the age of 15 years with opaque and single kidney stones treated with either SWL or microperc were retrospectively reviewed. Both groups were compared in terms of fluoroscopy and operative time, re-treatment, complications, success rate, and secondary and total number of procedures. Microperc and SWL were performed on 37 and 108 pediatric patients, respectively. The mean age of the patients was 5.91±4.03 years (1-15) and 8.43±4.84 (1-15) years in the SWL and microperc groups, respectively (P=0.004). The mean stone size was 11.32±2.84 (5-20) mm in the SWL group and 14.78±5.39 (6-32) mm in the microperc group (P<0.001). In the SWL group, 31 (28.7%) patients underwent a second SWL session and 6 (5%) had a third session. Finally, 95 (88%) patients were stone free at the end of the SWL sessions. In the microperc group, the stone-free rate was 89.2% in a single session (P=0.645). The mean duration of hospitalization was 49.2±12.3 (16-64) hours in the microperc group and 8.4±2.3 (6-10) hours per one session in the SWL group (P<0.001). The fluoroscopy time was significantly longer in the microperc group compared with the SWL group (147.3±95.3 seconds vs 59.6±25.9 seconds, P<0.001). The rate of requirement for an auxiliary procedure was higher in the SWL group than in the microperc group. The overall complication rates for the microperc and SWL groups were 21.6% and 16.7%, respectively (P=0.498). The results of our study demonstrate that microperc provides a similar stone-free rate and a lower additional treatment rate compared with SWL in the treatment of kidney stone disease in children.

Introduction:We aimed to compare extracorporeal shockwave lithotripsy (ESWL) and retrograde intrarenal surgery (RIRS) in pediatric patients with ≤2 cm renal pelvis and proximal ureteral stones.Methods:Medical records of 165 pediatric patients who underwent shockwave lithotripsy (SWL) or RIRS for upper urinary system stones up to 2 cm between January 2014 and December 2018 were retrospectively reviewed. After exclusions, the remaining 130 patients included 73 in the SWL group and 57 in the RIRS group. The groups were compared for demographic features, stone characteristics, operative data, success, and complications.Results:The mean stone volume was 308 ± 85 (54–800) and 336 ± 96 (60–720) mm3 in SWL and RIRS groups, respectively (P = 0.46). There were no significant differences in success rates (60% vs. 70%, SWL and RIRS), auxiliary treatment rates (16.4% vs. 14%), and complication rates (26% vs. 24.5%). The number of active procedural sessions and number of anesthesia sessions was higher in the RIRS group (P < 0.001 and P < 0.001, respectively), while the procedural time and anesthesia time were higher in the SWL group (P < 0.001 and P < 0.001, respectively). Stone size was found to be an independent success predictive factor for both the treatment modalities.Conclusions:Both SWL and RIRS have similar success, complication, and auxiliary treatment rates. RIRS was superior in terms of total procedure and anesthesia durations, while SWL was superior in terms of numbers of anesthesia sessions and active procedure sessions. As both have similar success rates, the more minimally invasive SWL should be chosen for pediatric upper urinary system stones of less than 2 cm size.

This study aims to compare the safety and efficacy of extracorporeal shock wave lithotripsy (SWL) and flexible ureteroscopy lithotripsy (f-URS) in treating urinary tract stones. We systematically searched PubMed, Embase, and Cochrane for literature comparing SWL with f-URS. The primary outcomes we focused on were stone-free rate (SFR) and complications; the secondary outcomes were operation time, hospital stay, retreatment rate, number of sessions, and auxiliary procedures rate. We used ReviewManager version 5.4.1 and STATA version 14.2 for meta-analysis. Seventeen studies with a total of 2,265 patients were included in the meta-analysis, including 1,038 patients in the SWL group and 1,227 patients in the f-URS group. The meta-analysis indicated that patients in the f-URS group had higher SFR than those in the SWL group [odds ratio (OR): 2.00, 95% confidence interval (CI): 1.29-3.12, p = 0.002]. In addition, we found no significant difference in complications (OR: 1.08, 95% CI: 0.85-1.37) between the two treatments. Also, we found that the retreatment rate and the auxiliary procedure rate in the f-URS group were significantly lower than those in the SWL group (OR: 0.08, 95% CI: 0.02-0.24, p < 0.00001; OR: 0.30, 95% CI: 0.11-0.83, p = 0.02). Moreover, the number of sessions in the f-URS group was significantly lower than that in the SWL group [mean difference (MD): -1.96, 95% CI: -1.55 to -0.33, p = 0.003]. However, the operation time and hospital stay in the f-URS group were significantly longer than those in the SWL group (MD: 11.24, 95% CI: 3.51-18.56, p = 0.004; MD: 1.14, 95% CI: 0.85-1.42, p < 0.00001). For 1-2-cm urinary stones, f-URS can achieve a higher SFR than SWL while having a lower retreatment rate, number of sessions, and auxiliary procedure rate. For urinary stones <1 cm, there was no significant difference in SFR between SWL and f-URS groups. The SWL group has a shorter operative time and hospital stay than the f-URS group.

Practice Variation in the Surgical Management of Urinary Lithiasis

The management of lower pole renal stones continues to evoke debate, and the ideal treatment remains controversial although several comparative studies have been conducted to evaluate various approaches. In an Internet and postal survey of 205 urologists, 88% preferred shock wave lithotripsy (SWL) for lower pole stones smaller than 10 mm in diameter, 65% for stones between 10 and 20 mm and 21% for stones greater than 20 mm.1 Current practice, however, may not reflect the efficacy of any particular modality. Lower pole calyceal stones continue to pose a dilemma owing to the dependent anatomical location and difficulty in clearance of stone fragments. Sampaio and Aragao2 first described the anatomical factors that would impede gravity-dependent drainage of stones from the lower pole calices. By performing endo-casts of the collecting system of cadaveric kidneys, this group postulated that the infundibulopelvic angle, infundibular length and spatial distribution of the lower pole calices all represented potential contributing features in the equation related to stone clearance. Sampaio and colleagues3 conducted a prospective trial to determine stone-free rates after SWL, aligned to these anatomical features. They found that 72% of patients were rendered stone-free when the lower pole infundibulopelvic angle was greater than 90 degrees, and only 23% of patients achieved a stone-free state when the angle was less than 90 degrees. Although SWL is less invasive, its limitations for lower pole calculi are outlined in an earlier study by McDougall and associates4 that retrospectively compared SWL to percutaneous nephrolithotomy (PCNL) for patients with lower pole stones. Overall, there was a significantly lower stone-free rate in patients treated with SWL (56%) compared with the stone-free rate of those undergoing PCNL (85%). Lingeman and coworkers5 conducted an analysis comparing the 2 modalities including outcomes of more than 3000 patients treated with SWL and 100 with PCNL. Stone-free rates for PCNL were significantly higher (90%) compared with SWL (59%). The authors recommended SWL as a first-line treatment for lower pole calculi measuring 10 mm or less in diameter and PCNL for larger stones. These retrospective studies formed the basis for a multicentre lower pole study group,6 which conducted the first prospective randomized trial with the aim of determining the optimal treatment of lower pole calculi. The group compared stone-free rates in 52 patients undergoing SWL and 55 randomized to PCNL. Overall stone-free rates for PCNL were far superior to that of SWL (95% v. 37%), retreatments were more common in the SWL group (16% v. 9%) and auxillary procedures were more frequent with SWL patients (16% v. 2%). Stratification by stone size was also consistent with prior studies7–9 demonstrating SWL stone-free rates of 68% for stones smaller than 10 mm in diameter, 55% for stones 10–20 mm and 29% for stones larger than 20 mm. The corresponding stone-free rates for PCNL were 100%, 93% and 86%, demonstrating that, for PCNL, stone-free rates are largely independent of stone size. PCNL is a more invasive procedure than SWL; however, overall complication rates in the Lower Pole Study were not significantly different.10 Techniques of percutaneous stone removal have improved in recent years, such that transfusion rates, reported at 25% in early studies, have decreased significantly and in more recent studies have been in the 1%–2% range.5,6 The introduction of balloon dilation of the tract, use of flexible nephroscopes, improved intracorporeal lithotripters and the trend to smaller or no nephrostomy tubes have decreased the overall morbidity rates for PCNL. The Lower Pole Study Group concluded that SWL constitutes reasonable first-line treatment for lower pole stones smaller than 10 mm in maximal diameter and recommended PCNL for stones greater than 10 mm.6 In a more recent study, Preminger11 also demonstrated the superior efficacy of PCNL over SWL in a multicentre randomized prospective trial of 112 patients with lower pole stones. Overall, only 35% of patients with lower pole calculi treated with SWL were rendered stone-free compared with a 96% success rate in the PCNL group. In addition to discrepant stone-free rates, a further concern with SWL is the higher rate of new stone formation caused by the increased frequency of retained stone debris in the lower pole calyx. Carr and colleagues12 looked at the incidence of new stone formation in 298 patients diagnosed as stone-free post-SWL and compared the findings with those for the group of 62 patients who had undergone PCNL and were rendered stone-free. At 1-year follow-up the patients in the SWL group had a significantly greater rate of new stone formation than patients who had undergone PCNL (22% v. 4%, p = 0.004). Although the rate of new stone formation in PCNL patients increased to 22% at 2 years, the rate was still higher in SWL patients at this time (35%). The authors also found that more new stones recurred in the lower and mid-calices compared with baseline location in the SWL group, which was not observed in the corresponding cadre of patients undergoing PCNL. This observation may be attributed to the dependent nature of the lower pole calices harbouring residual fragments, which may subsequently demonstrate growth and further clinical stone problems. Chen and Streem13 evaluated the issue of long-term outcome of post-SWL residual fragments in performing a prospective trial in patients with residual fragments measuring 4 mm or less in the lower pole calices. One-half of all patients experienced a symptomatic stone event or required intervention for stones within 2 years after SWL treatment. Concerns related to the potential higher morbidity with percutaneous stone removal concurrent with improvements in flexible ureteroscopes and the advent of the holmium:yttrium–aluminum–garnet laser have lead to interest in retrograde flexible ureteroscopy for treatment of lower pole calyceal stones.14 Ureteroscopy (URS) offers advantages in certain patient populations such as those with bleeding diathesis, those taking anticoagulants, those with renal anomalies such as a calyceal diverticulum, morbidly obese patients and those with orthopedic or other abnormalities with body habitus that may make SWL or PCNL challenging to perform.15–19 Other possible indications include prior SWL failure in stones with computed tomography (CT) attenuation value above 1000 Hounsfield units, which portends for lower fragmentation rates with SWL. The increased role of URS in treatment of intrarenal calculi paved the way for the second phase of the Lower Pole Study, which incorporated ureteroscopic management into a randomized trial with SWL and PCNL for lower pole calculi. Patients were divided into 2 groups. Group 1 included patients with stones 10 mm or smaller in diameter who were randomized to SWL or URS.20 Group 2 included patients with lower pole stones between 10 and 25 mm who were randomized to URS or PCNL. Stone-free rates were based on noncontrast CT scan at the 3-month mark posttreatment. PCNL demonstrated a significantly superior outcome over URS with respect to stone-free rates (71% v. 37%) for 10 to 25–mm lower pole stones.21 The theoretical advantage of URS for group 1 patients compared with SWL is not supported as there was no statistically significant difference observed in stone-free rates between the 2 populations.20 Interest in URS as a therapy for lower pole calyceal stones remains, however, as adjuvant measures such as use of ureteral access sheaths, displacement of lower pole stones with nitinol retrieval devices and ongoing improvements in flexible ureteroscope design all combine to increase the attractiveness of this modality.22,23 Lower pole calyceal stones will continue to challenge those interested in urology. Advances in techniques and the associated technology for performing percutaneous stone removal make this an ideal modality for lower pole stones larger than 10 mm. The minimally invasive nature of SWL positions this form of therapy as a preferred treatment for stones smaller than 10 mm. Interest in a retrograde ureteroscopic approach is likely to increase as the associated technology continues to evolve and improve.