A comparison of treatment modalities for renal calculi between 100 and 300 mm2: are shockwave lithotripsy, ureteroscopy, and percutaneous nephrolithotomy equivalent?

Erosion of embolization coil into the renal collecting system: Retrograde fragmentation of stone and coil via thulium laser lithotripsy

A 50-year-old female developed kidney stones on an eroded embolization coil 16 months after percutaneous nephrolithotomy (PCNL) related bleeding complications. Retrograde ureteroscopy and thulium laser lithotripsy was performed to fragment the exposed portion of the coil into clinically insignificant pieces. Thulium laser coil fragmentation remains a potential strategy to remove eroded coils and their associated kidney stones; however, recurrent stone formation on the coil stump may necessitate repeat intervention if this conservative approach is pursued over radical antegrade coil removal. This case highlights the importance of continued surveillance and multidisciplinary management in preventing and treating coil erosion after PCNL.

Five historical innovations that have shaped modern urological surgery

Throughout history, many innovations have contributed to the development of modern urological surgery, improving patient outcomes and expanding the range of treatment options available to patients. This article explores five key historical innovations that have shaped modern urological surgery: External shockwave lithotripsy, transurethral resection of prostate, cystoscope, perioperative prostate-specific antigen and robotic surgery. The selection of innovations for inclusion in this article was meticulously determined through expert consensus and an extensive literature review. We will review the development, impact and significance of each innovation, highlighting their contributions to the field of urological surgery and their ongoing relevance in contemporary and perioperative practice.

A robust localization approach for Percutaneous Nephrolithotomy (PCNL): A single-center retrospective study

BACKGROUND

Percutaneous Nephrolithotomy (PCNL) represents the gold standard treatment method for cases with large kidney stones. As a critical step in performing PCNL, the procedure of establishing a safe and accurate nephrostomy tract will dramatically impact the treatment quality of patients with large-sized kidney stones.

OBJECTIVE

This work attempts to describe a new and improved process of establishing an accurate nephrostomy tract and clinically evaluate the effectiveness and safeness of this proposed methodology.

METHODS

This work represents a retrospective single-center study carried out between August 2013 and November 2019. The collected samples consist of 937 patients who were operated on using PCNL coupled with our proposed procedure. Briefly, a preoperative B-ultrasonography was firstly performed to decide the puncture point in a simulated surgical position where was marked with ureteral catheter segments (2-3 cm). A computed tomography (CT) scan was followed to correct the anchor points in the simulated surgical position. After this, an accurate puncture operation was performed under the real-time guidance of intraoperative B ultrasound.

RESULTS

Examining this study, 851 subjects with renal stones and 86 subjects with ureteropelvic junction stones were included for the PCNL operation project. All samples were grouped with Guy's grading system: grade I, II, III, and IV patients there were 0.00%, 42.69%, 51.01%, and 6.30%, respectively. Among these patients, the average age was 48.49 ± 10.80 years old, with a male to female ratio of around 1.73:1.

CONCLUSIONS

This study showed that our developed method warrants an accurate and safe PCNL operation that involves the process of establishing the nephrostomy tract. Other advantageous attributes of this new PCNL process include negligible radiation exposure, lesser complications, and low failure rates. More importantly, this new localization approach is particularly attractive for hospitals that are new to the field of adopting PCNL considering its safeness, effectiveness, and learnability.

Transcatheter Angiographic Embolization of Percutaneous Nephrolithotomy-Related Bleeding: A Single-Center Experience

BACKGROUND

To evaluate the clinical characteristics and angiographic features of transcatheter angiographic embolization (TAE) in patients with active bleeding after percutaneous nephrolithotomy (PCNL).

METHODS

Between 2009 and 2018, 45 patients who underwent TAE for hemorrhage control after PCNL were reviewed retrospectively. Patient clinical characteristics and angiographic features of TAE were analyzed.

RESULTS

Of the 3148 patients, 45 (1.4%) patients were treated with TAE after PCNL. The interval from the bleeding episode to TAE was 3 days (1,6). Arterial laceration, arteriovenous fistula, and negative angiographic finding were found in 28 (62.2%), 7 (15.6%), and 10 patients (22.2%). Thirty-five patients (92.1%) achieved primary clinical success. The median-corrected hemoglobin decrease from bleeding episode to TAE was 52 g/L (25.25, 71.00). The median-corrected hemoglobin decrease rate from bleeding episode to TAE was 13.11 g/L·d (5.60, 26.12). The hemoglobin decrease from bleeding episode to TAE was lesser in negative angiographic patients (28.50 (10.75,51.25) g/L VS 53.7 (35.0,73.13) g/L) than in positive angiographic patients (P < 0.05).

CONCLUSIONS

TAE is a safe and effective treatment for post-PCNL bleeding patients. Previous kidney surgery is associated with a higher risk of TAE. Patients with bleeding from multiple negative angiographic findings can be considered for prophylactic embolization.

The comparison of perioperative outcomes between percutaneous nephrolithotomy and retrograde intrarenal surgery in elderly patients

OBJECTIVES

In this study, we aimed to compare the outcomes and complication rates of percutaneous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS) in elderly patients.

MATERIALS AND METHODS

Between April 2011 and January 2020, patients who underwent PCNL and RIRS for renal stone in elderly patients were retrospectively evaluated. The two groups' perioperative values, stone-free rates and complication rates were compared. Post-operative complications were noted according to the Clavien scoring system.

RESULTS

There were 89 and 72 patients in the PCNL and RIRS group respectively. The median age was 67 years in both the groups (P = .192). The stone size were 22.2 ± 3.5 mm and 19.9 ± 7.1 mm in the PCNL and RIRS group, respectively (P = .082). Stone-free rates were significantly higher in PCNL group (P = .021, P = .034). Also we found that overall complication and major complication rates were significantly higher in PCNL group (P = .016, P = .029).

CONCLUSION

Despite there was higher stone clearance in PCNL, the complication rates were higher compared with RIRS. So RIRS might be a safe alternative treatment method to PCNL in older patients.

Mini-percutaneous nephrolithotomy is a safe alternative to extracorporeal shockwave lithotripsy for high-density, renal stones: a prospective, randomised trial

OBJECTIVES

To compare the outcomes of miniaturised percutaneous nephrolithotomy (mini-PCNL) and extracorporeal shockwave lithotripsy (ESWL) in the management of 10-20 mm, non-lower pole, renal stones.

PATIENTS AND METHODS

This prospective randomised double-arm trial was conducted at a tertiary care hospital in Egypt from February to December 2020. Adult patients with single, non-lower pole, high-density (≥1000 HU) renal stones were randomised to receive mini-PCNL or ESWL. The stone-free rate (SFR); operative, fluoroscopy and hospitalisation times; blood loss; auxiliary procedures; retreatment; unscheduled hospital readmission; and complications were compared between the groups.

RESULTS

The primary analysis included 34 patients in the mini-PCNL group and 33 in the ESWL group. Overall, the SFR was 97.1% in the mini-PCNL group vs 30.3% in the ESWL group (P < 0.001). All patients in the ESWL group required retreatment, and none of them were stone-free after the first ESWL session. None of the patients in the mini-PCNL group required retreatment. The overall operative time, fluoroscopy time, auxiliary procedure, retreatment, and unscheduled hospital readmission were significantly higher in the ESWL group. The hospital stay and decrease in the haemoglobin level were significantly higher in the mini-PCNL group. The groups were comparable for the overall complication rate.

CONCLUSIONS

Mini-PCNL is more effective than ESWL for treating 10-20 mm, high-density, non-lower pole renal stones. Mini-PCNL has the advantages of a high SFR and abolishing the need for retreatment and re-hospitalisation.

Effectiveness of Flexible Ureterorenoscopy Versus Extracorporeal Shock Wave Lithotripsy for Renal Calculi of 5-15 mm: Results of a Randomized Controlled Trial

Background

Primary flexible ureterorenoscopy (URS) and extracorporeal shock wave lithotripsy (SWL) are treatment options in patients with renal calculi of 5-15 mm.

Objective

To compare effectiveness, complication rates, and pain scores between primary URS and SWL.

Design setting and participants

Between 2011 and 2016, patients with renal calculi between 5 and 15 mm were randomized to undergo either primary URS or SWL.

Outcome measurements and statistical analysis

Stone-free rate and size of residual fragments assessed by computed tomography after 3 mo, complications, and pain scores were evaluated.

Results and limitations

The study was prematurely closed after randomizing 44 patients due to poor accrual. The 3-mo stone-free rate and mean residual stone size were, respectively, 61% and 1.8 mm after URS and 48% and 2.4 mm after SWL. Early post-treatment pain scores were significantly higher after URS than after SWL on day 1 (3.3 vs 1.6, p =  0.02) and day 7 (5.2 vs 3.4, p =  0.04), but were no longer detectable after 3 wk and 3 mo, respectively. One Clavien-Dindo grade II complication was observed after URS (5%) and SWL (4%), while one (4%) grade IIIb complication was observed after SWL.

Conclusions

URS appears to be associated with higher early post-treatment discomfort, which could be associated with routine postoperative stenting. Owing to premature closure of this trial, the power was insufficient to formally compare URS and SWL; however, the present data might be informative to counsel patients about treatment outcomes and allow future meta-analyses.

Patient summary

This study was ended prematurely, but it contributes data about efficacy and side effects of different treatment options in patients with renal calculi.

Initial Experience and Evaluation of a Nomogram for Outcome Prediction in Management of Medium-sized (1-2 cm) Kidney Stones

BACKGROUND

The gold standard treatment for solitary medium-sized (1-2 cm) renal stones is not defined by recent guidelines, since management modalities including shockwave lithotripsy (SWL), retrograde intrarenal surgery (RIRS), and percutaneous nephrolithotomy (PNL) are recommended. Improved ability to predict patient outcomes would aid in patients' counseling and decision-making.

OBJECTIVE

To develop a nomogram predicting treatment failure, based on preoperative clinical variables, to be used in the preplanning setting.

DESIGN, SETTING, AND PARTICIPANTS

We recruited 2605 patients from 14 centers and carried out a multicenter retrospective analysis of 699 SWL, 1290 RIRS, and 616 PN L procedures performed as first-line treatment for 1-2-cm kidney stones. The variables evaluated included age, gender, previous renal surgery, body mass index, stone size, location, stone density, skin-to-stone distance, presence of urinary tract infections (UTIs), and hydronephrosis.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Multivariate logistic regression was fitted to predict treatment failure, defined as the presence of residual fragments >4 mm. A nomogram was developed based on the coefficients of the logit function.

RESULTS AND LIMITATIONS

A total of 2431 (93.3%) patients were stone free; 174 (6.7%) treatment failures were recorded and considered the event to be predicted. On univariate analysis, type of procedure, preoperative hydronephrosis, stone density, stone location, and laterality turned out to be statistically significant. Skin-to-stone distance, UTIs, and previous renal surgery were predictors of failure on multivariate analysis. Each variable was given a score based on statistical relevance. The main limitation of the current study is its retrospective nature.

CONCLUSIONS

This nomogram provides a prediction of treatment failure and need of reintervention for medium-sized kidney stones. External validation is needed to determine its reproducibility and validity.

PATIENT SUMMARY

We developed a preoperative model of treatment outcomes for 1-2-cm kidney stones. Its application may assist urologists to counsel patients with regard to stone management modality.

Is Percutaneous Nephrolithotomy the Modality of Choice Versus Extracorporeal Shockwave Lithotripsy for a 20 to 30 mm Single Renal Pelvic Stone with ≤1000 Hounsfield Unit in Adults? A Prospective Randomized Comparative Study

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.

Suction Use During Endourological Procedures

PURPOSE OF REVIEW

Equipment used in endourology is constantly evolving due to increasing incidence of urolithiasis. Suctioning has been used mainly in PCNL in conjunction with ultrasonic and ballistic devices for stone removal. Recently technological advances permitted the use of suctioning in more endourological techniques. This review aims to summarize the literature regarding these advancements and analyze the upcoming results.

RECENT FINDINGS

Several centers have conducted experimental and clinical studies on suctioning use during PCNL, mPCNL, and ureteroscopy and concluded that it is an effective and safe adjustment that improves stone-free rates and limits complication rates after these procedures. Suctioning use during common endourological procedures led to improved safety and efficacy among several indications. Due to the observational nature and small sample size of many studies, larger RCTs are needed to make safe conclusions.

A preoperative nomogram for sepsis in percutaneous nephrolithotomy treating solitary, unilateral and proximal ureteral stones

Background

Postoperative sepsis is a lethal complication for percutaneous nephrolithotomy (PCNL). An early predictive model combined local and systemic conditions is urgently needed to predict infectious events. We aim to determine the preoperative predictors of sepsis after PCNL in patients with unilateral, solitary, and proximal ureteral stones.

Methods

A total of 745 patients who underwent PCNL between January 2012 and December 2018 were retrospectively enrolled. Sepsis was defined based on the International Sepsis Definitions in 2001, and the preoperative factors were compared between the non-sepsis and sepsis groups. Univariable analysis and multivariable logistic regression analysis were conducted to determine the predictors for sepsis after PCNL. A nomogram was generated using the predictors.

Results

In this study, 35 patients (4.7%) developed sepsis after PCNL. Univariate analysis showed that post-PCNL sepsis was associated with the female, lower albumin, higher globulin, lower albumin globulin ratio (AGR < 1.5), preoperative fever, leukocytosis (WBC ≥ 10,000 cells/μL), positive urine culture, leukocyturia (≥50 cells/μL) and positive urine nitrite. Multivariate logistic regression analysis suggested that AGR < 1.5 (odds ratio [OR] = 5.068, 95% confidence interval [CI] [1.135-22.624], P = 0.033), positive urine culture (OR = 3.243, 95% CI [1.162-9.047], P = 0.025), leukocytosis (OR = 3.706, 95% CI [1.444-9.512], P = 0.006) and female (OR = 2.529, 95% CI [1.127-5.672], P = 0.024) were independent risk factors for sepsis. A nomogram was generated and displayed favorable fitting (Hosmer-Lemeshow test P = 0.797), discrimination (area under receiver operating characteristic curve was 0.807), and clinical usefulness by decision curve analysis.

Conclusions

Patients with certain preoperative characteristics, such as female, lower AGR, positive urine culture, and leukocytosis, who undergo PCNL may have a higher risk of developing sepsis. A cautious preoperative evaluation and optimized treatment strategy should be considered in these patients to minimize infectious complications.

Comparison between retrograde intrarenal surgery and percutaneous nephrolithotripsy in the management of renal stones: A meta-analysis

Percutaneous nephrolithotripsy (PCNL) is recommended as the first-line treatment for the management of kidney stones that are ≥2 cm in diameter. Retrograde intrarenal surgery (RIRS) has become increasingly preferred due to its high level of safety and repeatability, particularly in small stones. However, whether PCNL has superior efficacy and lower complication rates when compared with RIRS remains controversial. Therefore, the present meta-analysis was conducted to compare the clinical outcomes of patients treated with PCNL and RIRS as therapy for renal stones. Clinical trials published in PubMed, Web of Science, Excerpta Medica dataBASE (EMBASE), and the Chinese Biomedical Database (CBM) were systematically reviewed to evaluate the efficacy and safety profiles of patients with renal stones who were treated with PCNL or RIRS. Main outcomes measures included stone-free rate, operative time, hospital stay, and complication rate. Results were expressed as risk ratio (RR), or weighted mean difference (WMD) with 95% confidence intervals (CIs). Pooled estimates were calculated using a fixed-effects or random-effects model according to the heterogeneity among the studies. In total, 17 studies [4 randomized controlled trials (RCTs) and 13 cohort studies] involving 1,717 patients met the inclusion criteria, and were included in this meta-analysis. Pooled results showed that PCNL exhibited a significantly higher stone-free rate (RR=0.90, 95% CI: 0.86 to 0.95; P<0.001) but was associated with a longer hospital stay, when compared with RIRS (WMD=-2.72, 95% CI: -3.9 to -1.54; P<0.001). Operative time (WMD=7.86, 95% CI: -0.89 to 16.61; P=0.078) and complication rate (RR=0.71, 95% CI: 0.48 to 1.05; P=0.083) did not significantly differ between the groups. Subgroup analysis revealed that PCNL had a shorter operation time than RIRS in patients with stone sizes ≥2 cm (WMD=12.88, 95% CI: 4.77 to 20.99; P=0.002), and PCNL had a similar stone-free rate as RIRS when the estimates were pooled from RCTs (RR=0.88, 95% CI: 0.76 to 1.01; P=0.078). Compared with PCNL, RIRS had a significantly lower stone-free rate, shorter hospital stay, but a similar operation time and complication rate. Therefore, we propose that RIRS may be an alternative therapy to PCNL, with acceptable efficacy and complication rates for renal stones. Further large-scale, well-conducted RCTs are required to verify our findings.

Indications and contraindications for shock wave lithotripsy and how to improve outcomes

For over 35 years shock wave lithotripsy has proven to be an effective, safe and truly minimally invasive option for the treatment of nephrolithiasis. Various technical factors as well as patient selection can impact the success of the procedure. We used published work focusing on outcomes of shock wave lithotripsy, risk of complications, and strategies for improving stone fragmentation to create this review. Multiple patient and technical factors have been found to impact success of treatment. Skin to stone distance, stone density and composition, size and location of the stone within the urinary system all influence stone free rates. A slower rate with a gradual increasing voltage, precise targeting, proper coupling will improve stone fragmentation and decrease risk of complications. The selection of appropriate patients through a shared decision making process and attention to the technical factors that improve stone free rates is key to providing an effective treatment and patient satisfaction.

Small renal pelvis stones: Shock wave lithotripsy or flexible ureteroscopy? A match-pair analysis

OBJECTIVE

Kidney stones in renal pelvis may be treated using various methods. For larger stones, percutaneous nephrolitotomy (PNL) is the first choice of option; where for smaller stones, shock wave lithotripsy (SWL) or flexible ureteroscopy (F-URS) could be more suitable options. In this article we aimed to compare the outcomes of F-URS and SWL on the treatment of renal pelvis stones <10 mm.

MATERIAL AND METHODS

Files of patients treated with SWL and F-URS for renal pelvis stones <10 mm between March 2013 and May 2016 in our clinic were analyzed. For comparison, a match-pair analysis was designed. Complete stone removal was considered success.

RESULTS

Forty patients were treated using F-URS (Group 1) and 40 patients underwent SWL (Group 2). Patients were assessed the day after the last session of the procedure. The early stone-free rates were 70% (28/40) in Group 1, and 15% in Group 2 (p<0.05). The same analysis was performed after three months. Stone-free rates were 100% and 92.5% in Groups 1 and 2, respectively (p=0.079). Three patients in Group 2 were not stone free after 3 sessions of SWL and considered unsuccessful. They were all successfully treated by F-URS.

CONCLUSION

Even though there is no statistical difference among groups, our data may be interpreted as having better outcomes and tolerability with F-URS than SWL. We believe F-URS may have a great treatment prospect in this particular patient group.

A fluid-structure interaction (FSI)-based numerical investigation of peristalsis in an obstructed human ureter

Urine moves from the kidney to the bladder through the ureter. A series of compression waves facilitates this transport. Due to the highly concentrated mineral deposits in urine, stones are formed in the kidney and travel down through the urinary tract. While passing, a larger stone can get stuck and cause severe damage to ureter wall. Also, stones in the ureter obstructing the urine flow can cause pain and backflow of urine which in turn might require surgical intervention. The current study develops a 2D axisymmetric numerical model to gain an understanding of the ureter obstruction and its effects on the flow, which are critical in assessing the different treatment options. Transient computational analysis involving a two-way fully coupled fluid-structure interaction with the arbitrary Lagrangian-Eulerian method between the ureteral wall and urine flow is conducted with an obstruction in the ureter. The ureter wall is modeled as an anisotropic hyperelastic material, data of which, is based on biaxial tests on human ureter from previous literature, while the incompressible Navier-Stokes equations are solved to calculate urine flow. A finite element-based monolithic solver is used for the simulations here. The obstruction is placed in the fluid domain as a circular stone at the proximal part of the ureter. One of the objectives of this study is to quantify the effect of the ureteral obstruction. A sharp jump in pressure gradient and wall shear stress, as well as retrograde urine flow, is observed as a result of the obstruction.

Re-evaluation of the efficacy of tranexamic acid in reducing blood loss in percutaneous nephrolithotomy: a randomized clinical trial

BACKGROUND

Tranexamic acid was reported to reduce bleeding in patients undergoing percutaneous nephrolithotomy (PCNL). The current study was performed to re-evaluate the efficacy and safety of tranexamic acid in reducing PCNL-related blood loss.

METHODS

A total of 132 consecutive patients were randomized into two groups; the case group received 1 g of intravenous tranexamic acid before induction, followed by IV infusion of a fixed dose of 1 gr tranexamic acid at 8-hour intervals for the first 48 hours after the procedure, while the control group received normal saline as placebo. Demographic and clinical characteristics of patients were recorded. The collected data were then analyzed using χ2, t-test, and multivariate regression analysis with IBM SPSS Statistics software.

RESULTS

There was no significant difference in demographic characteristics of the two groups. Mean hemoglobin drop was 2.2±1.5 g/dL in tranexamic acid group and 2.4±1.5 g/dL in controls (P=0.312). The blood loss did not show significant difference between tranexamic acid and control groups (751±523 mL vs. 826±525 mL, P=0.416). Multivariate analysis has revealed that multiple access tracts is a risk factor for increased blood loss (P=0.014).

CONCLUSIONS

Tranexamic acid administration is not associated with significant reduction of PCNL-related blood loss. Our findings are unlike the results of few recent studies, thus warranting further investigations and new trials before the widespread use of this drug is considered safe in patients undergoing PCNL.

Research progress of percutaneous nephrolithotomy

Percutaneous nephrolithotomy (PCNL) is generally accepted as the gold standard treatment for the treatment of large kidney stones (> 2 cm). For nearly 40 years, with the continuous progress of technology and the constant updating of ideas, PCNL has made great progress. In this review, we discuss the current research progress, recent advancement and hot spot of the whole process of PCNL including anesthesia, position, puncture, dilation, lithotripsy approaches, perfusate, tube placement, hospitalization time, drug, treatment of residual stones, prognosis judgment and operation evaluation by summarizing the related research in this article.

Extracorporeal shock wave lithotripsy versus flexible ureterorenoscopy in the treatment of untreated renal calculi

Background

The reported success rates for treatments of kidney stones with either extracorporeal shock wave lithotripsy (ESWL) or flexible ureterorenoscopy (URS) are conflicting. We aimed to compare the efficacy and safety of ESWL and URS for previously untreated renal calculi.

Methods

All patients treated with ESWL or URS at our tertiary care centre between 2003 and 2015 were retrospectively identified. Patients with previously untreated kidney stones and a stone diameter of 5–20 mm were included. Stone-free, freedom from reintervention and complication rates were recorded. Independent predictors of stone-free and freedom from reintervention rates were identified by multivariable logistic regression and a propensity score-matched analysis was performed.

Results

A total of 1282 patients met the inclusion criteria, of whom 999 (78%) underwent ESWL and 283 (22%) had URS. During post-operative follow-up, only treatment modality and stone size could independently predict stone-free and freedom from reintervention rates. After propensity score matching, ESWL showed significantly lower stone-free rates [ESWL (71%) versus URS (84%)] and fewer patients with freedom from reintervention [ESWL (55%) versus URS (79%)] than URS. Complications were scarce for both treatments and included Clavien Grade 3a in 0.8% versus 0% and Grade 3b in 0.5% versus 0.4% of ESWL and URS treated patients, respectively.

Conclusions

Treatment success was mainly dependent on stone size and treatment modality. URS might be the better treatment option for previously untreated kidney stones 5–20 mm, with similar morbidity but higher stone-free rates and fewer reinterventions than ESWL.

The application of a novel integrated rigid and flexible Nephroscope in percutaneous nephrolithotomy for renal staghorn stones

Background

Renal staghorn stones are challenging for urologists to ensure maximum stone clearance and minimal morbidity. Percutaneous nephrolithotomy (PCNL) has become the gold standard treatment for renal staghorn stones. To assess the safety and efficacy of a novel integrated rigid and flexible percutaneous nephroscope(Rigi-flex nephroscope) in PCNL for renal staghorn stones.We present our initial experience with this new technique.

Methods

From March to July 2016, a prospective analysis of 3 patients with staghorn stones treated with Rigi-flex nephroscope in PCNLunder totally ultrasound guidance by paravertebral block (PVB) anesthesia was done. PCNL was performed with the rigid section of a 13-Fr Rigi-flex nephroscope firstly and the stones were disintegrated into fragments by holmium laser.Then the stones were removed by active flushout, followed by a search for residual stones in other inaccessible calyces with the flexible section. Finally, the residual stones were disintegrated into small fractions by holmium laser in situ or repositioned with a set of disposable retrieval baskets to pelvic or other accessible areas. The whole procedure was accomplished via only one nephrostomy tract. The operating time, stone-free rates (SFR), postoperative hemoglobin drop, complications, length of hospitalization, were recorded.

Results

The operation time were 89, 62 and 45 min, respectively, the postoperative hemoglobin drop was 1, 0.8 and 0.9 mg/dl, respectively.The postoperative Kidney-Ureter-Bladder (KUB) radiograph of the three patients showed no residual fragment >3 mm. No patients needed blood transfusion and suffered significant complications. The length of hospitalization was 9, 6 and 4 days, respectively. No patient needed multiple tracts PCNL or staged auxiliary measures one month after the operation.

Conclusions

The application of Rigi-flex nephroscope in PCNL under ultrasound guidance for staghorn stones has its unique advantages as monotherapy with increasing procedural stone free rate (SFR) via single nephrostomy tract, hence there is less morbidity as it does not require additional tracts dilation and staged auxiliary procedures combination. However, SFR should also be evaluated at a longer follow-up, particularly for staghorn stone, further large-scale multicenter prospective clinical trial are needed to verify its feasibility.

Ureteroscopy and laser stone fragmentation (URSL) for large (≥1 cm) paediatric stones: Outcomes from a university teaching hospital

INTRODUCTION

The treatment of large renal stones (≥1 cm) in paediatric patients is challenging. The usual treatment options include percutaneous nephrolithotomy (PCNL) or shockwave lithotripsy (SWL). There is a rise in the use of ureteroscopy and laser stone fragmentation (URSL) for paediatric stones; however, outcomes of treatment for large renal stones in this age group are still largely unknown.

OBJECTIVE

To investigate the outcome of URSL for large paediatric renal stones ≥1 cm treated at the present institution over the last 5 years.

METHODS

A retrospective review was performed of outcomes from the prospectively maintained stone database. Only paediatric patients undergoing ureteroscopic (rigid or flexible ureteroscopy (URS)) procedures for stones ≥1 cm were included. Patient demographics, operative details, stone burden, hospital stay, complications and stone clearance were recorded and analysed.

RESULTS

From April 2010 to June 2015, 18 paediatric patients with a mean age of 10.4 years (range 3.6-15) underwent 35 ureteroscopic procedures for large stones (≥1 cm). The stone location was in the kidney (n = 14), ureter (n = 1), and in both the kidney and ureter for the remaining three patients. Nine patients had multiple stones. There was a preceding history of PCNL in four patients, with one patient having URS combined with a PCNL. The mean follow-up was 2.7 years (range 0-5). A postoperative stent was inserted in 21 (60%) patients. The overall stone-free rate (SFR) was 89% for a mean of 1.8 procedures per patient (range 1-4) - see Summary Table below. There was an inability to access stone within a lower pole calyx in one patient, despite maximum deflection of the ureteroscope. No intra- or post-operative complications were noted, and mean hospital stay was 1.1 days (range 0-5).

DISCUSSION

Published papers in adult literature have shown that ureteroscopy and laser fragmentation (URSL) is a viable alternative to PCNL. Newer equipment and improved techniques have resulted in SFRs being comparable with PCNL. A recent systematic review reported an SFR of 91% for large adult stones (>2 cm) for a mean 1.45 procedures per patient, and an overall complication rate of 8.6%. The present study has also demonstrated excellent outcomes in the use of ureteroscopy and laser fragmentation for the management of large paediatric stones with no complications.

CONCLUSION

The results show that paediatric URSL for large stones achieves a good SFR with minimal morbidity and is a good treatment option in established endourological units.

Treatment for residual stones using flexible ureteroscopy and holmium laser lithotripsy after the management of complex calculi with single-tract percutaneous nephrolithotomy

This study validated the effectiveness and safety of the treatment for residual stones using flexible ureteroscopy (fURS) and holmium laser (0.6-1.2 J, 20-30 Hz) lithotripsy via a fiber with a 200-μm core diameter and 0.22 numerical aperture (NA) after the management of complex calculi with single-tract percutaneous nephrolithotomy (PCNL). Between January 2014 and June 2016, 27 consecutive patients with complex calculi underwent fURS and holmium laser lithotripsy after a planned single-tract PCNL. Among the 27 patients with complex calculi, 9 had full staghorn calculi, 7 had partial staghorn calculi, and 11 had multiple calculi. After the first single-tract PCNL session, the mean stone size and mean stone surface area were 18.0 ± 10.7 mm and 181.9 ± 172.2 mm², respectively. Treatment for residual stones with fURS and holmium laser lithotripsy was successfully completed and was performed without intraoperative complications. The mean operative time of the fURS procedure was 69.1 ± 23.6 min, and the mean hospital stay was 5.3 ± 2.4 days. The mean decrease in the hemoglobin level was 7.3 ± 6.5 g/l. After the fURS procedure, the overall stone-free rate was 88.9%. The overall postoperative complication rate was 14.8% (Clavien grade I 11.1%; Clavien grade II 3.7%). The current approach tested here combines the advantages of both PCNL and fURS and effectively manages complex calculi with a high stone-free rate (SFR) (88.9%). This approach also reduced the number of treatment sessions, the number of percutaneous access tracts, and the blood loss and potential morbidity associated with multiple tracts.

Management of upper ureteral stones exceeding 15 mm in diameter: Shock wave lithotripsy versus semirigid ureteroscopy with holmium:yttrium-aluminum-garnet laser lithotripsy

Objectives:

We conducted a retrospective study to evaluate the efficacy and outcome of shock wave lithotripsy versus semirigid ureteroscopy in the management of the proximal ureteral stones of diameter exceeding 15 mm.

Methods:

During the 2009−2014 study period, 147 patients presenting with the proximal ureteral stones exceeding 15 mm in diameter were treated. Both shock wave lithotripsy and ureteroscopy with laser lithotripsy were offered for our patients. A 6/8.9 Fr semirigid ureteroscope was used in conjunction with a holmium:yttrium–aluminum–garnet laser. The stone-free rate was assessed at 2 weeks and 3 months post-treatment. All patients were evaluated for stone-free status, operation time, hospital stay, perioperative complications, and auxiliary procedures.

Results:

Of the 147 patients who took part in this study, 66 (45%) had undergone shock wave lithotripsy and 81 (55%) underwent ureteroscopy. At the 3-month follow-up, the overall stone-free rate in the shock wave lithotripsy group was 39/66 (59%) compared to 70/81 (86.4%) in the ureteroscopic laser lithotripsy group. Ureteroscopic laser lithotripsy achieved a highly significant stone-free rate (p = 0.0002), and the mean operative time, auxiliary procedures, and postoperative complication rates were comparable between the two groups.

Conclusion:

In terms of the management of proximal ureteral stones exceeding 15 mm in diameter, ureteroscopy achieved a greater stone-free rate and is considered the first-line of management. Shock wave lithotripsy achieved lower stone-free rate, and it could be used in selected cases.

Kidney stones

Kidney stones are mineral deposits in the renal calyces and pelvis that are found free or attached to the renal papillae. They contain crystalline and organic components and are formed when the urine becomes supersaturated with respect to a mineral. Calcium oxalate is the main constituent of most stones, many of which form on a foundation of calcium phosphate called Randall's plaques, which are present on the renal papillary surface. Stone formation is highly prevalent, with rates of up to 14.8% and increasing, and a recurrence rate of up to 50% within the first 5 years of the initial stone episode. Obesity, diabetes, hypertension and metabolic syndrome are considered risk factors for stone formation, which, in turn, can lead to hypertension, chronic kidney disease and end-stage renal disease. Management of symptomatic kidney stones has evolved from open surgical lithotomy to minimally invasive endourological treatments leading to a reduction in patient morbidity, improved stone-free rates and better quality of life. Prevention of recurrence requires behavioural and nutritional interventions, as well as pharmacological treatments that are specific for the type of stone. There is a great need for recurrence prevention that requires a better understanding of the mechanisms involved in stone formation to facilitate the development of more-effective drugs.

Does morbid obesity influence the success and complication rates of extracorporeal shockwave lithotripsy for upper ureteral stones?

OBJECTIVE

The aim of the current study was to investigate whether obesity influences the outcome of extra-corporeal shockwave lithotripsy (ESWL) treatment for upper ureteral stones.

MATERIAL AND METHODS

This is a retrospective study of 134 patients who underwent ESWL between June 2011 and May 2014. Patients were divided into 2 groups. Group 1 comprised 94 patients of normal weight, and group 2 comprised 40 morbidly obese patients. Patients in both groups had upper ureteral stones.

RESULTS

The mean age of groups 1 and 2 was 45.6±12.1 and 45.3±15.5 years, respectively (p=0.98). There was no significant difference in demographic variables between the groups. The mean stone size in groups 1 and 2 was 81.7±25.7 mm(2) and 86.3±22.4 mm(2), respectively (p=0.51), the mean body mass index (BMI) was 27.4±2.9 and 42.9±2.1, respectively (p<0.01), the mean number of ESWL sessions was 2.4±0.6 and 2.4±0.7, respectively (p=0.97), and the mean follow-up time was 7.1±3.4 and 6.6±2.8 weeks, respectively (p=0.67). The overall stone-free rate was 82% in group 1 and 67% in group 2 (p=0.01).

CONCLUSION

It is well-known that morbidly obese patients have higher rates of anesthesia-related problems due to the comorbidities commonly observed in this population. In the current study, we found that ESWL is a safe and acceptable treatment option for morbidly obese patients with upper ureteral stones.

Arguments for choosing extracorporeal shockwave lithotripsy for removal of urinary tract stones

At a time when there is an almost unlimited enthusiasm and preference among urologists for endoscopic stone removal, we have found it essential to meet some of the frequently presented arguments on why extracorporeal shockwave lithotripsy (SWL) should not be used. We have based our considerations in this brief article on our 30-35 years' experience with the non-invasive or least invasive technique that SWL represents. Stone disintegration, requirement of repeated treatment sessions, the concern of residual fragments, complications and economic aspects are some points that are discussed.

Percutaneous nephrolithotomy vs. extracorporeal shockwave lithotripsy for treating a 20-30 mm single renal pelvic stone

Objective

To compare the efficacy, safety and cost of extracorporeal shockwave lithotripsy (ESWL) and percutaneous nephrolithotomy (PNL) for treating a 20–30 mm single renal pelvic stone.

Patients and methods

The computerised records of patients who underwent PNL or ESWL for a 20–30 mm single renal pelvic stone between January 2006 and December 2012 were reviewed retrospectively. Patients aged <18 years who had a branched stone, advanced hydronephrosis, a solitary kidney, anatomical renal abnormality, or had a surgical intervention within the past 6 months were excluded. The study included 337 patients with a mean (SD, range) age of 49.3 (12.2, 20–81) years. The patients’ criteria (age, sex, body mass index) and the stone characteristics (side, stone length, surface area, attenuation value and skin-to-stone distance) were compared between the groups. The re-treatment rate, the need for secondary procedures, success rate, complications and the total costs were calculated and compared.

Results

In all, 167 patients were treated by ESWL and 170 by PNL. The re-treatment rate (75% vs. 5%), the need for secondary procedures (25% vs. 4.7%) and total number of procedures (three vs. one) were significantly higher in the ESWL group (P < 0.001). The success rate was significantly higher in the PNL group (95% vs. 75%, P < 0.001), as was the complication rate (13% vs. 6.6%, P = 0.050). The total costs of primary and secondary procedures were significantly higher for PNL (US$ 1120 vs. 490; P < 0.001).

Conclusions

PNL was more effective than ESWL for treating a single renal pelvic stone of 20–30 mm. However, ESWL was associated with fewer complications and a lower cost.

Combined ureterorenoscopy for ureteral and renal calculi is not associated with adverse outcomes

Introduction

We intended to evaluate the feasibility and effectiveness of the simultaneous rigid and flexible ureteroscopic treatment of symptomatic ureteral and ipsilateral small simultaneous calyceal stones. Outcomes of combined therapy were compared with monotherapy alone.

Material and methods

In this retrospective study, group 1 consisted of 45 patients with middle or lower ureteral and ipsilateral small simultaneous calyceal stones treated by combined therapy. Group 2 included 45 patients with middle or lower ureteral stones only and treated by monotherapy. Stone characteristics, operative time, hospital stay, stone free rates, and complications were compared between groups 1 and 2. Stone free status was defined as no fragments and/or the presence of asymptomatic fragments smaller than 4 mm.

Results

Mean BMI were 29.3 ±0.9 kg/m² and 27.6 ±0.6 kg/m² in groups 1 and 2, respectively. Mean ureteral stone size (7.6 ±0.4 mm vs. 8.0 ±0.4 mm, p = 0.261) and ureteral stone burden (56.0 ±5.5 mm²vs. 54.8 ±6.1 mm², p = 0.487) were similar between groups. Mean renal stone size and renal stone burden for group 1 were 7.1 ±0.8 mm and 83.7 ±11.3 mm². The mean operative time was significantly longer (for a mean of 32.5±1.2 minutes) for group 1 (p = 0.001). Ureteral stents were left in 38 (84.4%) and 19 (42.2%) patients in group 1 and group 2 (p = 0.001). Hospital stay and complication rates were similar between groups. SFRs were 100% for ureteral stones in both groups and 88.9% for renal stones within group 1.

Conclusions

Simultaneous ureteroscopic treatment of the ureteral and ipsilateral small calyceal stones prolongs operative time and increases use of ureteral stent without leaving any residual renal stones.

Outcomes of Flexible Ureterorenoscopy for Solitary Renal Stones in the CROES URS Global Study

PURPOSE

We determined the efficacy and safety of flexible ureterorenoscopy for single intrarenal calculi and further stratified efficacy by stone burden.

MATERIALS AND METHODS

CROES collected prospective data on consecutive patients with urinary stones treated with ureterorenoscopy at 114 centers worldwide for 1 year. Only patients who underwent flexible ureterorenoscopy for a solitary renal stone were included in study. Preoperative and intraoperative characteristics, and postoperative outcomes were evaluated. Relationships between stone size and the stone-free rate, operative time, complications, hospital stay and need for re-treatment were determined.

RESULTS

A total of 1,210 patients with a solitary kidney stone less than 10 (52.2%), 10 to 20 (43.2%) and greater than 20 mm (4.6%) were treated with flexible ureterorenoscopy. The stone-free rate negatively correlated with stone size when adjusted for body mass index. Operative time positively correlated with stone size when adjusted for body mass index. The single session stone-free rate was 90% and 80% for stones less than 10 and less than 15 mm, respectively. Patients with stones greater than 20 mm achieved a 30% stone-free rate, more often needed re-treatment and were more often rehospitalized. There was no difference in the overall complication rate by stone size. However, patients with a stone greater than 20 mm showed a higher probability of fever after flexible ureterorenoscopy than those with a smaller stone.

CONCLUSIONS

Our data indicate that flexible ureterorenoscopy for a single intrarenal stone is a safe procedure. Best results after single session flexible ureterorenoscopy were obtained for stones less than 15 mm.

Complications in percutaneous nephrolithotomy

Percutaneous nephrolithotomy (PCNL) is generally considered a safe technique offering the highest stone-free rates after the first treatment as compared to the other minimal invasive lithotripsy techniques. Still, serious complications although rare should be expected following this percutaneous procedure. In this work, the most common and important complications associated with PCNL are being reviewed focusing on the perioperative risk factors, current management, and preventing measures that need to be taken to reduce their incidence. In addition, complication reporting is being criticized given the absence of a universal consensus on PCNL complications description. Complications such as perioperative bleeding, urine leak from nephrocutaneous fistula, pelvicalyceal system injury, and pain are individually graded as complications by various authors and are responsible for a significant variation in the reported overall PCNL complication rate, rendering comparison of morbidity between studies almost impossible. Due to the latter, a universally accepted grading system specialized for the assessment of PCNL-related complications and standardized for each variation of PCNL technique is deemed necessary.

Retrograde intrarenal surgery versus percutaneous nephrolithotomy for treatment of renal stones >2 cm: a meta-analysis

OBJECTIVE

To systematically review the efficacy and safety of retrograde intrarenal surgery (RIRS) versus percutaneous nephrolithotomy (PCNL) for the treatment of renal calculi >2 cm.

METHODS

We searched PubMed, Cochrane Library, Embase and the Chinese Biomedical Literature Database about RIRS and PCNL for the treatment of renal stones. The retrieval time ended in December 2013. All clinical trials were retrieved and their included references investigated. Two reviewers independently assessed the quality of all included studies, and the eligible studies were included and analyzed using the RevMan 5.2 software.

RESULTS

Two randomized controlled trials and six clinical controlled trials were included, involving a total of 590 patients. Our meta-analysis showed that there were not significant differences in stone-free rate (relative risk [RR] = 0.95, 95% confidence interval (CI) 0.88-1.02, p = 0.11) and fever (RR = 0.95, 95% CI 0.54-1.67, p = 0.85) between RIRS and PCNL. We found that hospital stay (weighted mean difference [WMD] = -2.10, 95% CI -3.08 to -1.11, p < 0.10) and bleeding (RR = 0.20, 95% CI 0.06-0.68, p = 0.01) were lower and operation time was longer (WMD = 19.11, 95% CI 7.83-30.39, p < 0.10) for RIRS.

CONCLUSION

RIRS is a safe and effective procedure. It can successfully treat patients with stones >2 cm with a high stone-free rate and significantly reduce hospital stay without increasing complications. RIRS can be used as an alternative treatment to PCNL in selected cases with larger renal stones. However, further randomized trials are needed to confirm these findings.

A prospective, randomized comparison of shock wave lithotripsy, retrograde intrarenal surgery and miniperc for treatment of 1 to 2 cm radiolucent lower calyceal renal calculi: a single center experience

PURPOSE

A prospective, randomized comparison of shock wave lithotripsy, retrograde intrarenal surgery and miniperc for the treatment of 1 to 2 cm radiolucent lower calyceal renal calculi was done to evaluate the safety and efficacy of these procedures.

MATERIALS AND METHODS

Patients with a single 1 to 2 cm radiolucent lower calyceal renal stone who underwent treatment between January 2012 and May 2013 were included in study. They were randomized to shock wave lithotripsy, retrograde intrarenal surgery and miniperc groups. Patient demographic profiles, success and re-treatment rates, auxiliary procedures and complications were analyzed.

RESULTS

A total of 45 patients were enrolled in each of the shock wave lithotripsy, retrograde intrarenal surgery and miniperc groups. Three, 2 and 4 patients, respectively, were excluded from final analysis due to a matrix stone diagnosis. Mean procedure and fluoroscopy times were significantly greater in the miniperc group than in the other groups. Hospital stay (3.1 days vs 3.1 hours and 1.3 days, p = 0.01) and the blood transfusion rate (13.3% vs 0% and 0%, p = 0.03) were significantly higher for miniperc vs shock wave lithotripsy and retrograde intrarenal surgery, respectively. The re-treatment rate (63.4% vs 2.1% and 2.2%, p <0.001) and the auxiliary procedure rate (20.2% vs 8.8% and 6.6%, p = 0.02) were significantly greater for shock wave lithotripsy than for retrograde intrarenal surgery and miniperc, respectively. The 3-month stone-free rate of shock wave lithotripsy, retrograde intrarenal surgery and miniperc was 73.8% (31 of 42 patients), 86.1% (37 of 43) and 95.1% (39 of 41), respectively (p = 0.01).

CONCLUSIONS

Miniperc and retrograde intrarenal surgery were more effective than shock wave lithotripsy to treat 1 to 2 cm radiolucent lower calyceal renal calculi in terms of a better stone-free rate, and lesser auxiliary and re-treatment rates. However, miniperc resulted in more complications, greater operative time and radiation exposure, and a longer hospital stay.

Results of retrograde intrarenal surgery in the treatment of renal stones greater than 2 cm

OBJECTIVE

To analyze the results of retrograde intrarenal surgery (RIRS) in patients with ≥2 cm stones treated in our center.

MATERIAL AND METHODS

A retrospective review of 106 patients with renal calculi underwent RIRS ≥2 cm (period January 2009-December 2011). The procedures were performed under general anesthesia as a source of fragmentation using the holmium laser (30 W Litho Quantasystem) and flexible ureteroscopes (X2 Flex Storz, Olympus P5) through ureteral access sheaths. It discusses demographic variables (age, medical history, antiplatelet or anticoagulant treatment, treatment of urolithiasis, BMI, ASA), treated stones variables (size, number, Hounsfield units, biochemical composition) and intra-and postoperative variables (operative time, number of pulses, hospital stay, complications) with the completion of a descriptive analysis of the same. To define our results we consider success to the complete absence of fragments or residual <5 mm posterior imaging tests.

RESULTS

The mean stone size was 2.46 cm treated, being the only stone in 87.7% of cases. The most frequent location was the renal pelvis stones (44%) followed by the lower calyx (39%). The postoperative complication rate was 6.7%, with all of little relevance. The success rate with a single procedure was 79.4% to 94.1% with retreatment.

CONCLUSION

RIRS is a valid alternative for the treatment of kidney stones ≥2 cm for its high success rate and few complications if performed in specialized centers.

Comparison of shock wave lithotripsy, flexible ureterorenoscopy and percutaneous nephrolithotripsy on moderate size renal pelvis stones

To compare success and complication rates of shock wave lithotripsy (SWL), flexible ureterorenoscopy (F-URS) and percutaneous nephrolithotripsy (PNL) according to modified clavien grading system of renal pelvis stones between 1 and 2 cm. The results of 149 patients were evaluated retrospectively. Patients were divided into three groups as 52 for SWL, 47 for F-URS and 50 for PNL. Complications were evaluated by modified Clavien grading system. In the first group, stone-free rates after a mean of 2, 6 sessions was 86 % (45/52). In Group 2, this ratio was 91.4 % (43/47), and in Group 3, it was 98 % (49/50). The success rate in Group 3 was significantly higher than other groups. Complication rates for Group 1, 2 and 3 were 7.6 % (4/52), 6.3 % (3/47) and 12 % (6/50), respectively. Although PNL was the most successful technique compared with other techniques, complications were also higher in this group. Even though PNL is the most successful, it should be performed for selected patient groups and indications should be carefully evaluated.

The impact of retrograde intrarenal surgery for asymptomatic renal stones in patients undergoing ureteroscopy for a symptomatic ureteral stone

BACKGROUND AND PURPOSE

In the era of rigid ureteroscopy (URS) for ureteral stones, asymptomatic renal stones were often left in place. With the advent of flexible URS, however, the treatment of such renal stones became an attractive option. Data are scarce regarding the impact of retrograde intrarenal surgery (RIRS) performed at the time of URS for a symptomatic ureteral stone in comparison with ureteral stone removal alone. The purpose of the study was to compare the outcomes of URS combined with RIRS with URS alone.

PATIENTS AND METHODS

A comparison between patients who underwent URS and RIRS (group A, n=47) and a matched control group of patients undergoing URS alone (group B, n=47) was performed. Matching was based on ureteral stone size and location, and preprocedural Double-J stent placement.

RESULTS

The median size of the largest ureteral stone in both groups was 8 mm with a mean total stone burden of 52.9 mm(2) (28.9) and 47 mm(2) (21.1) in groups A and B, respectively. Median renal stone size was 9 mm with a mean total stone burden of 84.1 mm(2) (40.3). Mean surgery time in groups A and B was 68 minutes (19.61) and 39 minutes (15.96), respectively (P<0.001). Median hospital stay was 1 day for both groups. The success rate for ureteral stone removal was 98% and 100% in groups A and B, respectively. Success rate for RIRS was 85% (40/47 cases). Hospitalization length and complications, mainly postoperative fever, did not differ significantly between the groups.

CONCLUSIONS

Managing asymptomatic renal stones at the time of URS for symptomatic ureteral stones significantly prolongs surgery duration but does not lengthen hospital stay, increase complications, or lower success rates. This combined approach reduces the need for future procedures and is probably more cost effective.

Retrograde intrarenal surgery in patients with horseshoe kidneys

Retrograde intrarenal surgery (RIRS) in patients with horseshoe kidneys (HSKs) remains poorly studied. The present study aimed to assess clinical success and stone-free rates in HSK patients with renal stones treated with flexible ureteroscopy. RIRS was attempted in 20 patients with 25 renal stones in HSK from December 2008 to January 2012. The patients were evaluated with imaging studies including plain abdominal radiography, intravenous urogram, abdominal ultrasonography or non-contrast tomography scan. Success rate was defined as stone-free or residual fragment less than 4 mm. Pre-operative, operative and postoperative data were retrospectively analyzed. A total of 20 patients were included in the present study (12 males, 8 females). 9 of 25 renal stones (36 %) were located in the lower calyx of the kidney, whereas 7 (28 %) in the middle calyx, 5 (20 %) in the renal pelvis and 4 (16 %) in the upper calyx. The mean stone size was 17.8 ± 4.5 mm. The stone-free rate was 70 % after a single procedure. 6 patients required shock wave lithotripsy and two of these were completely stone-free. Average hospital stay was 1.4 ± 0.7 days. Minor complications as classified by Clavien I or II occurred in 25 %. No major complications (Clavien III-V) occurred in the study group. RIRS is an effective and safe treatment modality for renal stones in patients with HSK. The procedure has minimal morbidity and high success rate.

Minimally invasive percutaneous nephrolithotomy: an alternative to retrograde intrarenal surgery and shockwave lithotripsy

PURPOSE

There is a lack of studies comparing shock wave lithotripsy (SWL), retrograde intrarenal surgery (RIRS) and minimally invasive percutaneous nephrolithotomy (MIP) in renal stone treatment. This study compared treatment outcome, stone-free rate (SFR) and stone-free survival (SFS) with regard to stone size and localization.

METHODS

This analysis included 482 first-time-treated patients in the period 2001-2007. Detailed clinical information, stone analysis and metabolic evaluation were evaluated retrospectively. Outcome, SFR and SFS were analyzed with regard to size (<1 vs. ≥1 cm) and localization (lower vs. non-lower pole).

RESULTS

Higher SFRs in lower and non-lower pole stones ≥1 cm were confirmed for RIRS and MIP (p < 0.0001). A regression model confirmed a higher risk of non-lower pole stone persistence for SWL versus RIRS (OR: 2.27, p = 0.034, SWL vs.

MIP (OR

3.23, p = 0.009) and larger stone burden ≥1 versus <1 cm (OR: 2.43, p = 0.006). In accordance, a higher risk of residual stones was found in the lower pole for SWL versus RIRS (OR: 2.67, p = 0.009), SWL versus

MIP (OR

4.75, p < 0.0001) and stones ≥1 cm versus <1 cm (OR: 3.02, p = 0.0006). In RIRS and MIP patients, more complications, stenting, prolonged disability, need/duration of hospitalization and analgesia were noticed (p < 0.05). Overall SFS increased from SWL, RIRS, to MIP (p < 0.001). SWL showed lower SFS for non-lower pole (p = 0.006) and lower pole stones (p = 0.007).

CONCLUSIONS

RIRS and MIP were shown to have higher stone-free rates and SFS compared to SWL. The price for better outcome was higher, considering tolerable complication rates. Despite larger preoperative stone burden, MIP achieved high and long-term treatment success.

MINI PCNL in a pediatric population

PURPOSE

We report our initial experience of MINI percutaneous nephrolithotomy (PCNL) in a pediatric population using a miniature nephroscope through a 16F metal access sheath.

METHODS

All pediatric patients who underwent PCNL from August 2007 to September 2010 using a 14F miniature nephroscope through a 16F metal access sheath for renal stone extraction were evaluated. Patients' demographic details, procedural information, and posttreatment outcomes were prospectively documented.

RESULTS

A total of 23 MINI PCNLs were performed on 23 kidneys of 12 patients whose ages ranged from 1.6 to 14.6 years. The median stone burden was 3.44 cm(2), and there were 11 "Staghorn" stones. The procedure was primary via a single puncture in 19 kidneys and secondary using a preexisting nephrostomy tract in 4 kidneys. Access was successful in all primary and two secondary cases, for a total of success rate of 91.3 %. Stones were fragmented using a Holmium laser and/or lithoclast, and fragments were irrigated or sequentially removed by various stone grasping devices. The mean procedural X-ray screening time and total stone extraction period were 4.5 and 109.4 min, respectively. The primary stone free rate was 83.6 %, which increased to 90.5 % after treating the residual fragments. Postoperative hydrothorax developed in one patient, which required a chest drain. Symptoms of chest infection and positive urine culture were detected in one and two patients, respectively.

CONCLUSIONS

Our initial experience supports previous reports that MINI PCNL is safe and effective for the management of renal stones in children.

Flexible ureteroscopy and laser lithotripsy for stones >2 cm: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

Urinary stones >2 cm are traditionally managed with percutaneous nephrolithotomy (PCNL). Recently, flexible ureteroscopy and laser lithotripsy) (FURSL) has been used to manage them with comparable results. In a comparative study of renal stones between 2 and 3 cm, FURSL was reported to need less second-stage procedures and be just as effective as PCNL. Our purpose was to review the literature for renal stones >2 cm managed by ureteroscopy and holmium lasertripsy.

MATERIALS AND METHODS

A systematic review and quantitative meta-analysis was performed using studies identified by a literature search from 1990s (the first reported large renal stones treated ureteroscopically) to August 2011. All English language articles reporting on a minimum of 10 patients treated with FURSL for renal stones >2 cm were included. Two reviewers independently extracted the data from each study. The data of studies with comparable results were included into a meta-analysis.

RESULTS

In nine studies, 445 patients (460 renal units) were reportedly treated with FURSL. The mean operative time was 82.5 minutes (28-215 min). The mean stone-free rate was 93.7% (77%-96.7%), with an average of 1.6 procedures per patient. The mean stone size was 2.5 cm. An overall complication rate was 10.1%. Major complications developed in 21 (5.3%) patients and minor complications developed in 19 (4.8%) patients. A subgroup analysis shows that FURSL has a 95.7% stone-free rate with stones 2-3 cm and 84.6% in those >3 cm (P=0.01), with a minor complication rate of 14.3% and 15.4%, respectively, and a major complication rate of 0% and 11.5%, respectively.

CONCLUSION

In experienced hands, FURSL can successfully treat patients with stones >2 cm with a high stone-free rate and a low complication rate. Although the studies are from high-volume experienced centers and may not be sufficient to alter everyday routine practice, this review has shown that the efficacy of FURSL allows an alternative to PCNL.

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

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.