Role of Minimally Invasive Percutaneous Nephrolithotomy Techniques—Micro and Ultra-Mini PCNL (<15F) in the Pediatric Population: A Systematic Review

Endoscopic combined intrarenal surgery versus percutaneuos nephrolithotomy for complex pediatric stone disease: A comparative analysis of efficacy and safety

INTRODUCTION

Decision-making for complex pediatric urinary system stone disease is still a challenge for pediatric urologists. The interest in supine percutaneous nephrolithotomy (PCNL) is increasing among centers to achieve high surgical success rates with less morbidity. Despite advanced retrograde intrarenal surgery armamentarium, percutaneous approaches remain the first-line surgical treatment modality for >2 cm and complex renal stones. There are no comparative studies yet in the literature for pediatric endoscopic combined intrarenal surgery (ECIRS) OBJECTIVE: In this study, we aimed to contribute to the literature by evaluating the safety and efficacy of ECIRS by comparing it with PCNL.

STUDY DESIGN

Patients under 18 years of age who underwent PCNL and ECIRS for urinary tract stone disease at our Pediatric Urology department between 2012 and 2024 were included. Preoperative (demographic characteristics, stone characteristics, biochemical parameters), perioperative (duration of surgery, number of accesses, lasing and fluoroscopy times, endoscopic and fluoroscopic stone-free rates) and postoperative (hospital stay, urinary tract infection, complication and radiological stone-free rates) parameters were retrospectively evaluated.

RESULTS

A total of 68 children [28 (41%) girls and 40 (59%) boys] aged 5 (0-17) years were included in the study. ECIRS was performed in 19 (28%), supine in 28 (41%) and prone PCNL in 21 (30%) patients. Age (p = 0.029), Guy's stone score (p < 0.001), S.T.O.N.E. (p < 0.001), and Seoul National University Renal Stone Complexity (S-ReSC) scores (p = 0.001) for preoperative parameters were found to be higher in ECIRS group over both PCNL methods (Summary Table). However, Clinical Research Office of the Endourological Society (CROES) score was seen lower for ECIRS group patients compared to other groups (p = 0.028). Surgery time (in favor of supine over prone PCNL), fluoroscopy time (in favor of ECIRS and Supine PCNL over Prone PCNL), preferred laser type (prone PCNL group was mostly performed with holmium laser, whereas other groups were balanced between Holmium and Thulium Fiber Laser) and exit strategy (the preferred exit strategy was DJ Stent in most of the ECIRS patients, whereas nephrostomy tube was used in some of the PCNL group) showed significant difference among the groups as perioperative parameters (p = 0.042, <0.001, <0.001, <0.001, respectively). Surgery time was lower for supine PCNL compared to prone PCNL. For postoperative parameters, stone-free rates, complication rates and urinary tract infections were similar between the 3 groups, while a difference was detected in terms of length of hospital stay in favor of ECIRS over both supine and prone PCNL (p = 0.006).

DISCUSSION

The current trial suggests that stone-free and complication rates of ECIRS and supine PCNL were similar in the pediatric complex stone patients. Although, the stones in the ECIRS group we found to be more complex. Also, ECIRS was superior to PCNL in terms of fluoroscopy exposure and hospital stay.

CONCLUSION

With the widespread use of new generation ureteral access sheaths and flexible ureterorenoscopes, ECIRS may have an important role in treatment of complex pediatric kidney stones.

Urological Guidelines for Kidney Stones: Overview and Comprehensive Update

BACKGROUND

Evidence-based guidelines are published by urological organisations for various conditions, including urolithiasis. In this paper, we provide guidance on the management of kidney stone disease (KSD) and compare the American Urological Association (AUA) and European Association of Urologists (EAU) guidelines.

METHODS

We evaluate and appraise the evidence and grade of recommendation provided by the AUA and EAU guidelines on urolithiasis (both surgical and medical management).

RESULTS

Both the AUA and EAU guidelines provide guidance on the type of imaging, treatment options, and medical therapies and advice on specific patient groups, such as in paediatrics and pregnancy. While the guidelines are generally aligned and based on evidence, some subtle differences exist in the recommendations, but both are generally unanimous for the majority of the principles of management.

CONCLUSIONS

We recommend that the guidelines should undergo regular updates based on recently published material, and while these guidelines provide a framework, treatment plans should still be personalised, respecting patient preferences, surgical expertise, and various other individual factors, to offer the best outcome for kidney stone patients.

PCNL vs. two staged RIRS for kidney stones greater than 20 mm: systematic review, meta-analysis, and trial sequential analysis

INTRODUCTION

Percutaneous nephrolithotomy (PCNL) is considered the gold standard treatment for kidney stones greater than 20 mm. However, retrograde intrarenal surgery (RIRS) may achieve the same stone-free rate with repeated procedures, and potentially fewer complications. This study aimed to compare the efficacy and safety of PCNL and two-staged RIRS.

EVIDENCE ACQUISITION

We conducted a systematic search in PubMed, Embase, Scopus, Cochrane, and Web of Science for studies comparing PCNL and RIRS for kidney stones greater than 20mm. The primary outcome is stone-free rate (SFR) of PCNL and RIRS (repeated once if needed). Secondary outcomes were SFR of PCNL versus RIRS (single procedure), operative time, hospital stay, need for auxiliary procedures, and complications. We performed a subgroup analysis for randomized trials, non-randomized trials, and patients with solitary kidney. We performed a trial sequential analysis for the main outcome.

EVIDENCE SYNTHESIS

We included 31 articles, with 1987 patients in the PCNL and 1724 patients in RIRS. We confirmed the traditional result that after a single procedure PCNL has a higher SFR. We also found that comparing the SFR of PCNL and RIRS, repeated up to two times if needed, no difference in SFR was observed. Surprisingly, only 26% (CI95 23%-28%) of the patients required a second RIRS. In the trial sequential analysis, the last point of the z-curve was within futility borders. We observed that PCNL has a higher incidence of complications (RR=1.51; CI95 1.24, 1.83; P<0.0001; I2=28%), specifically CD2 (RR=1.82; CI95 1.30, 2.54; P=0.0004; I2=26%) and longer hospital stay (MD 2.57; 2.18, 2.96; P<0.00001; I2-98%). No difference was observed regarding operative time.

CONCLUSIONS

RIRS repeated up to two times is equivalent to PCNL in terms of the SFR and may have the same safety.

Outcomes of ultraminipercutaneous nephrolithotomy in infants: our experiences at a single center in an endemic region

OBJECTIVE

In this study, we aimed to contribute to the literature by sharing the perioperative and postoperative outcomes of infants (0-24 months) who underwent ultra-mini percutaneous nephrolithotomy (PNL) for kidney stones in our clinic.

METHODS

Infants under 24 months old with kidney stones of 2 cm and larger, who applied to our clinic between January 2018 and May 2023, were included in the study. The patients' demographic and clinical characteristics were obtained from the medical records. The collected data were analyzed retrospectively.

RESULTS

A total of 26 patients were included in the study. The mean age of the patients was 17.3 ± 3.90 (12-24) months. The mean operation time was 50.7 ± 6.43 min. The mean stone size was 2.66 ± 0.59 cm. Stone-free was achieved in 23 patients (88.5%). In one patient (3.8%) with residual fragments, SWL was performed, and in two patients (7.7%), RIRS was performed to achieve stone-free. Postoperatively, fever was observed in 3 patients (11.5%). There were no patients requiring blood transfusion.

CONCLUSIONS

In experienced centers, ultra-mini-PNL performed by experienced surgeons is an effective and reliable treatment option for infants under 24 months of age with kidney stones larger than 2 cm. It provides high-stone clearance rates and low complication rates.

Influencing Factors of Massive Hemorrhage and High-Grade Renal Vascular Injury after PCNL: A Retrospective Comparative Study

Purpose

Severe hemorrhage after percutaneous nephrolithotomy (PCNL) is a rare but alerting event. In this study, we report the factors affecting massive hemorrhage after PCNL, various levels of vascular damage during renal angiography, and the therapeutic effect of superselective renal artery embolization (SRAE). Patients and Methods. A retrospective analysis was performed on the data of 69 patients with postoperative PCNL hemorrhage who underwent SRAE from January 2010 to March 2021. Inclusion criteria for all cases were failure of conservative treatment for severe renal hemorrhage after surgery and then treatment with SRAE. In addition, 98 patients without significant hemorrhage after PCNL were randomly selected as the control group. All clinical data are confirmed by imaging and laboratory examinations. We performed univariate and multivariate analyses to find risk factors of massive hemorrhage and high-grade renal vascular injury after PCNL.

Results

A total of 69 patients underwent angiography, 64 of which received SRAE due to positive hemorrhages detected by angiography. Urinary tract infection (OR (95% CI) = 11.214 (2.804∼44.842)), high blood pressure (OR (95% CI) = 5.686 (1.401∼23.083)), and no hydronephrosis (OR (95% CI) = 0.189 (0.049∼0.724)) are the most important factors leading to massive hemorrhage after PCNL. In patients who need SRAE after hemorrhage, high-grade vascular injury (grade III) is related to advanced age and decreased hemoglobin.

Conclusion

During the perioperative period of PCNL, patients with a risk of hypertension, urinary tract infection, and no hydronephrosis should be strengthened to monitor their high risk of postoperative hemorrhage. For patients with postoperative hemorrhage, we can use the patient's age and decreased hemoglobin before and after operation for analysis. In this way, individualized assessment can greatly improve the efficiency of SRAE treatment.

Paediatric percutaneous nephrolithotomy (P-PCNL) reporting checklist

OBJECTIVE

To develop a reporting checklist that serves to improve and standardise reporting in studies pertaining to paediatric percutaneous nephrolithotomy (PCNL).

METHODS

Based on findings from systematic review of literature, a draft list of items was formulated. By process of review and revisions, a finalised version was established and consensus achieved.

RESULTS

The finalised version of the checklist covers four main sections, which include the following areas: study details, pre-operative, operative and post-operative information. There are 18 further sub-items. Recommendations deemed to be of high importance to include are highlighted in bold.

CONCLUSION

This practical tool can aid clinicians and researchers when undertaking and reviewing studies on paediatric PCNL. This is highly relevant given the current heterogeneity that exists as well as debate in best practice patterns.

A comparative analysis of the efficacy and safety of mini-percutaneous nephrolithotomy performed in the supine and prone positions for the treatment of pediatric kidney stones: a single-center experience

Mini-percutaneous nephrolithotomy (MPCNL), which has a smaller tract size (14-20 Fr) than conventional percutaneous nephrolithotomy, has been shown to be safe and effective in pediatric patients with large and complex upper urinary tract stones. This study aimed to compare the efficacy and safety of MPCNL between the supine and prone positions in a pediatric population. The data of pediatric patients who underwent MPCNL at our center between January 2010 and March 2023 were retrospectively analyzed. According to the surgical position, the patients were divided into the prone (Group P) and supine (Group S) groups. In both groups, dilatation was performed using 14-18 Fr metallic dilators. The two groups were compared in terms of perioperative data, postoperative stone-free rates (SFRs), and complications. There were 36 (59%) patients in Group P and 25 (41%) patients in Group S. Stones were mostly located in the pelvis (49.2%) and second most frequently in the lower pole (27.9%). Fluoroscopy time was shorter in Group S but did not statistically significantly differ compared to Group P (p = 0.181). However, operation time was statistically significantly shorter in Group S (73.8 ± 35 vs. 99.8 ± 37.4 min, p = 0.008). Although there was no significant difference, relatively higher SFR were detected in Group S (88% vs. 83%, p = 0.725). Endoscopic combined intrarenal surgery (ECIRS) was performed on six (24%) patients in Group S, and the SFR was 100% among these patients. There was no significant difference between the two groups in terms of the presence of complications (16.7% vs. 16%, p = 0.945). Both supine and prone MPCNL appear to be safe and effective in the pediatric age group, with similar stone-free and complication rates. In the supine procedure, the operation time is shortened compared to the prone. In addition, simultaneous retrograde access has the potential to increase the overall success rate of surgery.

Outcome of Mini-PCNL Under Loco-Regional Anesthesia: Outcomes of a Systematic Review

PURPOSE OF REVIEW

Miniaturized PCNL (mi-PCNL) for stone disease is performed under a general anesthesia. However, the role of loco-regional anesthesia in mi-PCNL and its outcomes are not well defined yet. Here, we review the outcomes and complications of loco-regional anesthesia for mi-PCNL. A Cochrane-style review was performed in accordance with the preferred reporting items for systematic reviews to evaluate the outcomes of loco-reginal anesthesia for URS in stone disease, including all English language articles from January 1980 and October 2021.

RECENT FINDINGS

Ten studies with a total of 1663 patients underwent mi-PCNL under loco-regional anesthesia. The stone-free rate (SFR) for mi-PCNL under neuro-axial anesthesia ranged between 88.3 and 93.6%, while it ranged between 85.7 and 93.3% for mi-PCNL under local anesthesia (LA). The conversion rate to another anesthesia modality was 0.5%. The complications ranged widely between 3.3 and 85.7%. The majority were Grade I-II complications and none of the patients had grade V complications. Our review shows that mi-PCNL under loco-regional anesthesia is feasible with good SFR and a low risk of major complications. The conversion to general anesthesia is needed in a small minority, with the procedure itself being well tolerated and a big step towards establishing an ambulatory pathway for these patients.

Pediatric Stone Disease: Current Trends and Future Directions

Pediatric nephrolithiasis is less common in children than in adults but the incidence has been rising rapidly, and it is now a public health and economic burden in the United States. There are challenges unique to children that should be taken into consideration when evaluating and managing pediatric stone disease. In this review, we present the current research on risk factors, emerging new technologies for treatment of stones and recent investigations on prevention of stones in this population.

Ureteroscopy and lasertripsy with pop dusting using high power holmium laser for large urinary stones > 15 mm: 6.5-year prospective outcomes from a high-volume stone center

INTRODUCTION

Ureteroscopy and stone lasertripsy (URSL) is a recognized technique for treatment of urinary tract stones. Holmium:Yag laser has been successfully used for this purpose for the last two decades. More lately, pulse modulation with Moses technology and high power lasers have been introduced with the result of faster and more efficient stone lasertripsy. Pop dusting is a two-stage combined treatment using a long pulse Ho:YAG laser, initially in contact mode with the stone 'dusting' (0.2-0.5 J/40-50 Hz) followed by non-contact mode 'pop-dusting' (0.5-0.7 J/20-50 Hz). We wanted to look at the outcomes of lasertripsy for renal and ureteric stones using a high-power laser machine.

METHODS

Over a period of 6.5 years (January 2016-May 2022), we prospectively collected data for patients undergoing URSL for stones larger than 15 mm treated using high power Ho:YAG laser (60W Moses or 100W laser). Patient parameters, stone demographics and outcomes of URSL were analyzed.

RESULTS

A total of 201 patients, underwent URSL for large urinary stones. In 136 patients (61.6%) stones were multiple and the mean single and cumulative stone size was 18 mm and 22.4 mm respectively. A pre- and post-operative stent was placed in 92 (41.4%) and 169 (76%) respectively. The initial and final stone free rate (SFR) were 84.5% and 94% respectively and 10% patients underwent additional procedure to achieve stone free status. 7 (3.9%) complications were recorded, all related to UTI/sepsis, with 6 Clavien II and 1 Clavien IVa complication.

CONCLUSION

Dusting and pop-dusting has shown to be successful and safe with the ability to treat large, bilateral or multiple stones with low retreatment and complication rates.

Antegrade Percutaneous Retrieval of Upward Migrated Double-J Stent in Very Small Size Pediatric Patients Under Ultrasonic Guide

Purpose: To evaluate the safety of antegrade percutaneous retrieval migrated ureteral stent in very small size pediatric patients with ultramini instruments under ultrasonography guide. Materials and Methods: A total number of 10 out of 115 patients who were referred to our center with upward migrated Double-J (DJ) were candidates for antegrade approach from 2017 to 2020. The pyelocalyceal system was punctured in a prone position by using an 18-gauge disposable needle with Chiba tip and visualization of the upper tract by 3.5 MHz ultrasonic guidance. Then 0.038-inch J tipped guide wire was passed through the needle and the tract was dilated up to 6F under ultrasonographic guide. The 8F access sheath was positioned over the 6F dilator. The semirigid 6F ureteroscope was introduced through the sheath and DJ was removed with a grasper. Results: The mean age was 11.4 ± 5.48 months. The mean time from the previous surgery to DJ removal procedure was 6.4 ± 0.84 weeks. The mean operation time was 11.7 ± 1.76 minutes. All the patients were discharged from the hospital within the 1st day. There were no serious complications (grade 3, 4, or 5) according to Clavien-Dindo classification. Conclusion: The antegrade retrieval of upward migrated DJ with ultramini instrument under ultrasonographic guidance in failed cases of retrograde approach is a safe and effective approach in very small size pediatric patients.

The technological future of percutaneous nephrolithotomy: a Young Academic Urologists Endourology and Urolithiasis Working Group update

PURPOSE OF REVIEW

With advancements in surgical technology along with procedural techniques, this article throws light on the latest developments and applications of artificial intelligence (AI), extended reality, 3D (three-dimensional) printing and robotics in percutaneous nephrolithotomy (PCNL).

RECENT FINDINGS

This review highlights the applications of AI in PCNL over the past 2 years. Mostly studies have been reported on development of machine learning (ML) based predicting models and identification of stone composition using deep learning convolutional neural network (DL-CNN). But owing to the complexity of the models and lack of generalizability, it is still not incorporated in the routine clinical practice. Extended reality based simulation and training models have enabled trainees to enhance their skills and shorten the learning curve. Similar advantages have been reported with the use of 3D printed models when used to train young and novice endourologists to improve their skills in percutaneous access (PCA). Applications of robotics in PCNL look promising but are still in nascent stages.

SUMMARY

Future research on PCNL should focus more on generalizability and adaptability of technological advancements in terms of training and improvement of patient outcomes.

Changes in Urine Composition and Risk of Kidney Stone Disease Following Bariatric Surgery: A Systematic Review over Last 2 Decades

PURPOSE OF REVIEW

The association of kidney stone disease (KSD) and gastrointestinal (GI) surgery has been well established. With a rising obesity crisis, we wanted to see the correlation of urinary composition in patients undergoing bariatric surgery and their risk of KSD. The objective of this paper is to perform a systematic review and meta-analysis of literature to evaluate the changes in urinary composition and risk of KSD following bariatric surgery.

RECENT FINDINGS

A total of seven studies (2498 patients) underwent bariatric surgery with a mean age of 46.7 years and a male:female ratio of 1:3. The most popular bariatric surgery was the Roux-en-Y procedure. Meta-analysis of the studies showed that significant decrease in urinary calcium, citrate, and urate, and increase in urinary oxalate. There was also a nonsignificant volume reduction in the post-operative cohort. The decrease in urinary citrate and increase in urinary oxalate are both predisposing factors of stone formation. There is strong evidence that bariatric surgery results in significant changes in urine composition in keeping with the increased risk of developing KSD. This identifies useful therapeutic targets in the prophylactic management of patients who have undergone bariatric surgery.

Scoping review of recent evidence on the management of pediatric urolithiasis: summary of meta-analyses, systematic reviews and relevant randomized controlled trials

This scoping review aimed to evaluate and summarize the recent 10 year pediatric urolithiasis literature with a particular focus on systematic reviews, randomized-controlled trials (RCT) and meta-analysis. The systematic literature search performed on September 1, 2021, restricted to the recent 10 years, focused on pediatric urolithiasis that are RCTs, meta-analysis and systematic reviews. The summarized literature included etiology, diagnostics, medical and surgical management. GRADE criteria are used to evaluate and standardize the reporting of evidence quality. A total of 33 relevant articles were included. The recent high-level studies included topics of genetic and diet association with pediatric stone formation, diagnostic assessment, medical management intervention including medical dissolution and expulsion therapy. The study extended to include the efficacy and safety of extracorporeal lithotripsy, percutaneous nephrolithotomy and retrograde intrarenal surgery. However, evidence quality was ranked "very-low" or "low". Based on the GRADE criteria downgrading of the quality level was due to heterogeneity and low precision. A majority of the RCTs were categorized as having a "high" to "uncertain" risk of bias. The relevant RCTs, meta-analyses and systematic reviews within the past decade are of low quality. Consequently, the research provided no clear evidence-based recommendations for managing pediatric urolithiasis. More rigorous research and high-quality studies are needed to determine the best practices.

Is percutaneous nephrolithotomy effective and safe for children with solitary kidney?

PURPOSE

To evaluate the safety and efficacy of percutaneous nephrolithotomy (PCNL) in pediatric patients with solitary kidneys and kidney stones.

METHODS

Thirty-nine patients (group A) with solitary kidney under 18 years of age who underwent PCNL between January 2015 and December 2021 were evaluated and analyzed. Forty-two patients (group B) with bilateral kidneys who underwent PCNL were determined as the control group and included in the analysis. Intraoperative and postoperative data such as demographic data, stone localization, bleeding and transfusion rates, operation time, complications, hospital stay, stone-free rates (SFR) and kidney function (glomerular filtration rate (eGFR)) were compared between the two groups. PCNL was performed with all patients in the prone position. Only a laser was used to fragment the stone in all cases. Stone-free was defined as the absence of residual stone fragments ≥ 2 mm in maximum diameter at 3 months on kidney, ureter and bladder (KUB) graphy, ultrasonography (US) or non-contrast tomography (NCCT).

RESULTS

The mean ages of the patients in Group A and B were 7.5 ± 2.6 and 8.5 ± 3.1 years, respectively. The mean stone size was 16.5 ± 4.1 and 17.0 ± 3.2 mm in group A and group B, respectively (p = 0.49). SFR rates in Groups A and B were 97.4% and 95.2% (p = 1.00). There was no statistically significant difference in terms of the operation time, perioperative blood transfusion, hemoglobin decrease and Clavien grade 1 complication rates (p > 0.05). However, double-J (JJ) stent placement, duration of nephrostomy and hospital stay were longer in the solitary kidney group (p < 0.05). There was a significant improvement in creatinine and eGFR levels in both groups at the postoperative sixth month (p < 0.05).

CONCLUSION

Our results show that PCNL is a safe and effective method in pediatric patients with solitary kidneys.

Comparison between standard, mini and ultra-mini percutaneous nephrolithotomy for single renal stones: a prospective study

PURPOSE

Based on the current trend of miniaturization of instruments used in percutaneous nephrolithotomy (PCNL), it is necessary to compare different PCNL modalities regarding their access sheath size used. Thus, the safety and efficacy among standard, mini and ultra-mini PCNL (s-PCNL, m-PCNL, um-PCNL) were compared.

METHODS

We performed a prospective, non-randomized trial between January 2018 and July 2020. Patients with stones classified as Guy's stone score grade I were included. The set-up for s-PCNL and m-PCNL included a 30 Fr and 22 Fr percutaneous tract, respectively. In both set-ups, an ultrasonic/ballistic lithotripter was utilized. In the case of um-PCNL, a 12 Fr percutaneous tract was established. A high-power laser was used for lithotripsy. Hemoglobin drop, complication rate, length of hospital stay (LOS), stone-free rate (SFR) and operation time were evaluated.

RESULTS

A total of 84 patients, 28 patients per method, were evaluated. Hemoglobin drop was higher in the s-PCNL group when compared to m-PCNL (p = 0.008) and um-PCNL groups (p < 0.001), while um-PCNL group had the slightest hemoglobin drop. LOS was similar between s-PCNL group and m-PCNL group, but um-PCNL group required shorter hospital stay than the other two modalities (p < 0.001). The complication and transfusion rates as well as SFR did not differ between groups. Operation time in the um-PCNL set-up was longer compared to s-PCNL (p < 0.001) and m-PCNL (p = 0.011), whereas s-PCNL and m-PCNL did not differ significantly.

CONCLUSION

m-PCNL showed less hemoglobin drop, but similar operation time and SFR when compared to s-PCNL. um-PCNL showed even less hemoglobin drop, but the operation time was longer compared to the two other modalities.

The safety and efficiency of a 1470 nm laser in obtaining tract hemostasis in tubeless percutaneous nephrolithotomy: a retrospective cross-sectional study

Objective

It is challenging to perform a tubeless percutaneous nephrolithotomy (PNL) in patients with tract bleeding. The present study was designed to study the safety and efficacy of the 1470 nm laser for hemostatic completion in tubeless PNL patients with tract bleeding.

Patients and Methods

Between January 2020 and October 2021, 120 patients were retrospectively included and divided into two groups. The hemostasis group included 60 patients receiving tubeless PNL, in which a 1470 nm laser was used to manage tract bleeding. The other group included 60 patients receiving tubeless PNL in which the hemostasis procedure was not performed, serving as the control group. The differences in the patients’ demographic characteristics, procedural information, and posttreatment outcomes between the two groups were statistically compared.

Results

The differences associated with sex, age, weight, body mass index, urine culture, stone burden, calyx of puncture, degree of hydronephrosis and comorbidities between the two groups were not statistically significant. Compared with the control group, the hemostasis group showed greatly reduced blood loss (0.61 ± 0.31 vs. 0.85 ± 0.46 g/dL) and decreased postoperative hospitalization duration (2.83 ± 0.81 vs. 4.45 ± 0.91 days). The differences in operative time, stone-free rate, Visual Analogue Score and postoperative complications between the two groups were not statistically significant. In the subgroup analysis, the obese patients and patients with moderate to severe hydronephrosis in the hemostasis group also showed a significantly less blood loss (0.51 ± 0.22 vs. 0.83 ± 0.48 g/dL; 0.54 ± 0.27 vs. 0.85 ± 0.47 g/dL, respectively) and shorter length of postoperative hospitalization (2.62 ± 0.51 vs. 4.47 ± 1.19 days; 2.97 ± 0.63 vs. 4.41 ± 0.91 days, respectively) than those in the control group.

Conclusions

Our results demonstrated that 1470 nm laser is a safe, feasible and effective method to obtain tract hemostasis in tubeless PNL.

Paediatric stone management: innovations and standards

PURPOSE OF REVIEW

The aim of this study was to discuss current trends and recent developments in the surgical management of paediatric urolithiasis.

RECENT FINDINGS

Medical expulsive therapy (MET) is considered as an option for the treatment of children with ureter stones. Extracorporeal shockwave lithotripsy (SWL) remains as a first option for majority of kidney stones and upper ureter stones. Advances in endourology have led to increased adoption of retrograde intrarenal surgeries (RIRS) and percutaneous nephrolithotomy (PCNL/mini-PCNL/ultra-mini-PCNL/micro-PCNL).

SUMMARY

Management of paediatric stone disease has developed significantly in the past decade. However, the evidence in the literature remains disproportional to these advances. Well designed multicentric studies are still needed to compare effectiveness and safety of these procedures.

Guideline Adherence of Paediatric Urolithiasis: An EAU Members' Survey and Expert Panel Roundtable Discussion

Background: Paediatric nephrolithiasis has increased globally, requiring standardized recommendations. This study aims to assess the paediatric urolithiasis care between EAU members along with the statements of three experts in this field. Methods: The results of an electronic survey among EAU members comparing the guideline recommendations to their current practice managing paediatric nephrolithiasis in 74 centres are contrasted with insights from an expert-panel. The survey consisted of 20 questions in four main sections: demographics, instrument availability, surgical preferences and follow-up preferences. Experts were asked to give insights on the same topics. Results: A total of 74 responses were received. Computerised Tomography was predominantly used as the main imaging modality over ultrasound. Lack of gonadal protection during operations was identified as an issue. Adult instruments were used frequently instead of paediatric instruments. Stone and metabolic analysis were performed by 83% and 63% of the respondents respectively. Conclusions: Percutaneous Nephrolithotomy is the recommended standard treatment for stones > 20 mm, 12% of respondents were still performing shockwave lithotripsy despite PNL, mini and micro-PNL being available. Children have a high risk for recurrence yet stone and metabolic analysis was not performed in all patients. Expert recommendations may guide clinicians towards best practice.

Totally ultrasound-guided minimally invasive percutaneous nephrolithotomy in children: Is it safe?

OBJECTIVE

The objective of the study was to assess the outcome and feasibility of ultrasonography (US)-guided minimally invasive percutaneous nephrolithotomy (mini-PCNL) in children.

MATERIALS AND METHODS

Twenty-five children with upper urinary tract stones who had undergone US-guided mini-PCNL from June 2017 to June 2020 were enrolled in this study. Patients' demographic information and post-treatment results were retrospectively gathered and analysed. Pyelocaliceal system was punctured in prone position using US guidance, and the tract was dilated using single-shot dilation technique. All steps of renal access were done using only US. Mini-PCNL in all cases was done by using 15 Fr rigid nephroscope. Stones were fragmented with a pneumatic lithotripter and evacuated.

RESULTS

The patients' mean age was 6.30 ± 3.25 years (range: 1.5-15). The mean stone size was 16.04 ± 3.93 mm (range: 10-30). The mean access time to the stone was 1.50 ± 0.62 min (range: 1-4). The mean operation time was 94.66 ± 3.05 min (range: 90-100 min). The final stone-free rate was 96%. Post-operation fever occurred in 4 (16%) patients who were treated successfully with an antibiotic. No major complications occurred.

CONCLUSIONS

We recommend US-guided mini-PCNL as a harmless alternative treatment option, in children with renal calculi due to its excellent outcomes and little complications.

Safety and efficacy of minimally invasive percutaneous nephrolithotomy for infantile nephrolithiasis. Single centre experience from Pakistan

OBJECTIVE

To assess the efficacy and safety of mini-percutaneous nephrolithotomy (PCNL) for small renal stones 1-2 cm in size in infants less than one year.

MATERIAL AND METHODS

This descriptive case series was conducted in the department of pediatric urology Institute of Kidney Diseases Peshawar, Pakistan, from March 2019 to March 2022. All the patients underwent mini-PCNL in prone position under GA with 14 Fr access sheath and 10 Fr nephroscope. Stone clearance was assessed by non-contrast CT KUB at 30th postoperative day. Patients with no residual fragments on the non-contrast CT KUB were defined as stone-free. Patients with residual fragments of any size were defined as procedure failure. Safety was determined in terms of intra and postoperative complications.

RESULTS

A total of 51 infants were included in the study. The mean age of patients was 9.6 + 1.8 (5-12 month). The mean stone size was 15.8 + 2.7 (10-21) mm in length and 12.3 + 2.2 (8-17) mm in width. PCNL mean operative time was 51.6 ± 7.1 (40-70) minutes. Complete stone clearance at one month was observed in 46 (90.2%) patients. Residual fragments were seen in 5(9.8%) patients with a mean size of 1.6 + 0.4 (0.9-2.0) mm. None of the patients required any additional procedure for clearance of stones. In 7 (13.7%) patients, some post-operative complications were observe, all were grade I complications, including fever in 5(9.8%) and transient hematuria in 2(3.9%) patients.

CONCLUSION

Mini-PCNL is a safe and effective treatment for renal stones in infants measuring 1-2 cm with high SFR and an acceptable complication rate.

Minimally invasive surgery for pediatric renal and ureteric stones: A therapeutic update

The incidence of pediatric urolithiasis (PU) is growing worldwide. The corresponding therapeutic methods have become a research hot spot in pediatric urology. PU has the characteristics of abnormal metabolism, easy recurrence, and immature urinary system development, which make its treatment different from that of adults. Pediatric urologists should select the optimal treatment modality to completely remove the stones to prevent recurrence. Currently, the curative treatments of PU include extracorporeal shock wave lithotripsy (ESWL), ureteroscopy, retrograde intrarenal surgery, percutaneous nephrolithotomy (PCNL), laparoscopic, robot-assisted laparoscopic, and open surgery. This review aims to conduct a therapeutic update on the surgical interventions of both pediatric renal and ureteric stones. It accentuates that pediatric surgeons or urologists should bear in mind the pros and cons of various minimally invasive surgical treatments under different conditions. In the future, the treatment of PU will be more refined due to the advancement of technology and the development of surgical instruments. However, a comprehensive understanding of the affected factors should be taken into account by pediatric urologists to select the most beneficial treatment plan for individual children to achieve precise treatment.

Comparison of Mini-Percutaneous Nephrolithotomy by Standard and Miniperc Instruments in Pediatric Population: A Single-Center Experience

Objective:

The objective of this study was to compare mini-percutaneous nephrolithotomy (PCNL) performed by standard and Miniperc techniques in pediatric patients.

Materials and Methods:

This was a retrospective study conducted at our institution between January 2012 and December 2017. The outcomes of pediatric renal stones treated by mini-PCNL done by Miniperc and standard techniques were compared in terms of the drop in the hemoglobin, stone-free rate, and analgesic requirement in the first 24 h.

Results:

A total of 57 children (age: 1–16 years), who underwent mini-PCNL by Miniperc equipment (n = 23) and standard equipment (n = 34), were included in this study. The postoperative mean drop in hemoglobin was significantly higher in mini-PCNL done by standard compared to the Miniperc technique. The stone-free rate was 95.65% in the Miniperc group and 94.12% in the standard mini-PCNL group. The need for analgesics was significantly lower in the Miniperc group compared to the standard mini-PCNL group (P = 0.0002). In the Miniperc group, the majority of the patients required only one dose of analgesics, whereas, in the standard mini-PCNL group, around 44% of the patients required three or more than three doses of analgesics to reduce postoperative pain.

Conclusion:

Both the techniques were safe and efficacious in the management of pediatric renal stone and stone clearance. However, the Miniperc technique resulted in significantly less pain and a lower dosage of analgesics.

THE FUNCTIONAL STATE OF THE RENAL PARENCHYMA AFTER VARIOUS VIDEO ENDOSURGICAL METHODS OF TREATMENT OF PATIENTS WITH LARGE AND COMPLEX KIDNEY STONES

The work is based on the analysis of literature data devoted to the problem of preserving the functional state of the kidneys with various video endoscopic methods of surgical treatment of large and complex kidney stones. The purpose of the review is to highlight the likelihood of deterioration in the functional state of the kidneys in the postoperative period. A detailed analysis of postoperative outcomes in various minimally invasive methods of treatment of patients with large and complex kidney stones was carried out, with an overview of the possibility of using dynamic nephroscintigraphy as a method of objectively assessing the functional state of the kidneys.

Minimal invasive percutaneous nephrolithotomy (Mini-PCNL) in children: Ultrasound versus fluoroscopic guidance

BACKGROUND

Miniaturization of endoscopic instruments in percutaneous nephrolithotomy (PCNL) allowed less invasive procedures with low complication rates, especially in children. This study was conducted to evaluate the safety and efficacy of ultrasonography-guided (USG) versus fluoroscopy-guided (FG) mini-PCNL in children.

MATERIALS AND METHODS

This is a retrospective comparative study conducted from June 2015 to June 2020. The sample included 70 children (35 pateints underwent USG mini-PCNL and 35 pateints underwent FG mini-PCNL). They were compared mainly by the patients' demographic characteristics, procedural information, and post-treatment outcomes. In the USG mini-PCNL group, puncturing was performed using a 3.5 MHz US probe, whereas fluoroscopy was utilized in the FG mini- PCNL group.

RESULTS

Both groups were comparable in terms of gender, previous history of failed ESWL, and hydronephrosis grade. The mean stone burden was 15.94 ± 3.69 mm and 19.20 ± 7.41 mm in USG and FG groups, respectively (p = 0.024). The stonefree rate (SFR) was 97.1% in the USG group and 94.3% in the FG group, which was not statistically significant (p = 0.16). Mean operative time in the USG group and FG group was 69.00 ± 13.33 minutes and 63.48 ± 16.90 minutes, respectively. Four (11.4%) patients in the FG group required blood transfusions to restore the hemodynamic state (p = 0.039). Fever was detected in 4 (11.4%) patients in the USG group and 15 (31.4%) patients in the FG group (p = 0.041).

CONCLUSIONS

In children, mini PCNL under USG is safe and as effective as fluoroscopy.

Mini PCNL: A viable single stage treatment for pediatric nephrolithiasis in resource limited countries

INTRODUCTION

There is increasing enthusiasm for the value of mini PCNL for pediatric stone clearance. In developing countries, it is important to arrange a single stage treatment as a significant proportion of patients do not comply with repeated treatments, such as SWL.

OBJECTIVE

To assess the safety, feasibility and outcomes of Mini PCNL in a pediatric cohort.

MATERIALS AND METHODS

Retrospective analysis was performed of all paediatric patients undergoing Mini-PCNL at our institute between December 2016 and December 2019. Data was collected on stone size, stone clearance rate, complications, fluoroscopic exposure, mean procedural time and length of hospital stay. Follow up data included imaging to assess stone free status at 1 and 3 months postoperatively.

RESULTS

Mini PCNL was performed in 113 pediatric patients, a total of 135 procedures, accounting for bilateral disease in 22. The age range was from 1 to 14 years with a mean age of 8.45 ± 3.14 years. The mean stone burden was 2.1 ± 0.4 cm. Partial and complete staghorn stones were observed in 7 and 3 patients, respectively. The mean operative time was 63.8 ± 13.2 min (range: 25 min to 116min) and mean length of stay was 4.3 ± 2.2 days. Primary stone clearance was achieved in 91.1% (123 patients). Ancillary procedures were undertaken in 10 patients resulting in a secondary clearance rate of 97.0% (131 patients) at 3 months. Complications occurred in 16.3% (22 patients) using the modified Clavien Classification. Metabolic abnormalities were seen in 56.7% of patients with hypocitraturia and hypercalciuria being the most common abnormalities.

DISCUSSION

Our study reports a clearance rate of 91.1%, whereas, Zeng et al. documented a stone clearance rate of 80.4%. This contrast may be attributed to the difference in followup imaging protocols of the two studies and the energy source used for fragmentation. The incidence of complications with PCNL ranges from 10.6% to 36.3%, we found complications in 16.3% of our cohort. Our study is limited due to its retrospective design with a short follow-up protocol. Computed tomography being gold standard for qualitative and quantitative assessment of stone burden was not used in all patients to assess the preoperative stone size. Furthermore, postoperatively stone clearance was determined on the basis of ultrasound and x-ray films that could limit the accuracy of our stone clearance rate.

CONCLUSION

Our study suggests that mini PNCL in pediatrics patients is an effective single stage treatment for definitive stone clearance with an acceptable complication risk.

Predictors and Strategies to Avoid Mortality Following Ureteroscopy for Stone Disease: A Systematic Review from European Association of Urologists Sections of Urolithiasis (EULIS) and Uro-technology (ESUT)

CONTEXT

While kidney stone disease is common and ureteroscopy (URS) is perceived as minimally invasive, there is mortality associated with treatment.

OBJECTIVE

The aim of this review was to ascertain the number of mortalities from URS for stone disease over the past three decades, identify relevant patient risk factors and predictors of mortality, and summarise the key recommendations so that similar instances can be avoided, and lessons can be learnt.

EVIDENCE ACQUISITION

A systematic literature search was conducted following Cochrane and Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) methodology for English-language article reporting on data from 1990 to December 2020. Data collated from each study included patient and stone characteristics, number of mortalities, and cause of death.

EVIDENCE SYNTHESIS

Fifteen studies met our inclusion criteria and revealed a total of 72 mortalities from ten countries. The age range of reported patients varied from 21 to 89 yr, with over 60% being above 65 yr of age and 97% with some comorbidity. Based on available data, death reports in females were three times more than those in males. The stone size ranged from 10 to 38 mm. Treatment of larger stones corresponded to a longer operative time, with procedural duration varying from 30 to 120 min. Of the reported causes of mortality in 42 patients, the aetiology was sepsis in over half of the patients, with other causes being cardiac-related, respiratory-related, multiorgan failure, and haemorrhagic complications.

CONCLUSIONS

Although the reported URS mortality rate seems to be low, there has been a rise in deaths over the past decade. Efforts must be made to have preoperative urine culture, and reduce operative time and stage procedures in patients with a large stone burden. Care must be taken in patients with robust preoperative assessment, intraoperative techniques, and postoperative monitoring for early detection of complications with interdisciplinary management of complex cases.

PATIENT SUMMARY

We reviewed the risk factors associated with postureteroscopy mortality and ways to minimise this. Evidence shows that although reported mortality remains low, there seems to be an increase in mortality in the past decade and urologists must remain vigilant of this.

Which factors affect the success of pediatric PCNL? Single center experience over 20 years

OBJECTIVE

We aimed to investigate the impact of surgeons' experience on pediatric percutaneous nephrolithotomy (PCNL) outcomes.

MATERIALS AND METHODS

Between June 1997 and June 2018, 573 pediatric patients with 654 renal units underwent PCNL for renal stone disease by senior surgeons. Data were divided into two groups, group-1 (n = 267), first ten years period, group-2 (n = 387); second ten years period.

RESULTS

Mean ± SD age of patients was 7.6 ± 4.9 (1-17) years. The stone-free rates (SFR) assessed after 4 weeks were 74.9% vs. 83.4% in group-1 vs. group-2, respectively (p = 0.03). The mean operation time, fluoroscopy time, and the number of patients requiring blood transfusion significantly decreased in group 2 (100.4 ± 57.5 vs. 63.63 ± 36.3, 12.1 ± 8.3 vs. 8.3 ± 5.4, and 24.3% vs. 2.9%; p < 0.001, p < 0.001, and p = 0.002 in group-1 versus group-2, respectively). On multivariate analysis, increasing stone size increased operation time (p < 0.001), fluoroscopy time (p < 0.001), intraoperative and postoperative blood transfusion rates (p = 0.006 and p = 0.018, respectively), and hospital stay (p = 0.002) but was not associated with change of glomerular filtration rate (GFR) (p = 0.71). Sheath size also correlated with increased fluoroscopy time (p < 0.001), operation time (p < 0.001), intraoperative blood transfusion (p < 0.001) and hospital stay, but sheath size did not affect postoperative blood transfusion (p = 0.614) or GFR change (p = 0.994).

CONCLUSIONS

The percutaneous nephrolithotomy (PCNL) is a minimally invasive procedure and is well accepted because of its lower complication rate and high efficiency for pediatric patients. Stone and sheath size are predictive factors for blood loss and hospital stay. During 20 years, our fluoroscopy time, operation time, blood loss, and complication rates decreased, and stone-free rate increased.

Role of Mini-Percutaneous Nephrolithotomy in the Management of Pediatric Stone Disease: A Systematic Review of Literature

Introduction: Kidney stone disease in the pediatric setting is rare, but the incidence is rising. Mini-percutaneous nephrolithotomy (mPCNL) is one of the newer surgical interventions to have been developed in recent decades. The aim of this study was to carry out a systematic review (SR) to formally evaluate the safety and efficacy of pediatric mPCNL, which was defined as PCNLs using tract size between 15F and 20F. Methods: An SR was carried out in accordance with Cochrane guidelines and A MeaSurement Tool to Assess systematic Reviews (AMSTAR) checklist. Original studies reporting on outcomes of mPCNL with 20 or more patients (aged ≤18 years) were included. Results: Eight studies were finally identified, which satisfied our predefined criteria. This included two randomized trials and six cohort studies. A total of 384 patients with a weighted mean age of 7.5 years (range: 0.5-18 years) and a male:female ratio of 3:2 underwent mPCNL. The weighted mean stone size was 1.2 cm (range: 0.8-3.5 cm). The weighted mean operative time and length of hospital stay were 76.8 minutes (range: 20-120 minutes) and 4.6 days (range: 1-33 days), respectively. The most common location(s) of stones were lower pole (57%) and renal pelvis (24.3%). The weighted mean initial and overall stone-free rates were 87.9% (range: 76%-97.5%) and 97% (range: 91.3%-100%), respectively. None of the cases required intraoperative conversion to standard PCNL. Complications occurred in 19% (n = 73) of patients. The weighted mean transfusion rate reported across studies was 3.3% (range: 0%-10.3%). Conclusions: mPCNL is safe and effective in the pediatric population. Further randomized studies will help determine its formal role in pediatric endourology and help guideline recommendations accordingly.

Comparison of efficacy and safety of minimally invasive procedures for 10-20 mm pediatric renal Stones-A bayesian network meta-analysis

OBJECTIVE

To assess the efficacy and safety of various minimally invasive procedures for 10-20 mm pediatric renal stones by Bayesian network meta-analysis (NWA).

METHODS

We searched clinical comparative trials published in Pubmed, Embase, Cochrane Library from inception to 12 April 2020. Two researchers evaluated the quality and extracted data individually. Data was analyzed using STATA and GEMYC R package.

RESULTS

The overall network meta-analytic outcome of stone free rate (SFR) in a single session revealed that Retrograde Intrarenal Stone Surgery (RIRS), miniaturized percutaneous nephrolithotomy (mPCNL) and PCNL showed superiority to extracorporeal shockwave lithotripsy (ESWL). Statistical significance was not detected between any intervention from our pooled network analysis of complication rate. SMP was the most likely to ranking in first place to render stone free status, and it also showed the lowest risk possibility of complications. Mini-PCNL had longer operation time and hospitalization than ESWL. The global and loop inconsistency evaluation demonstrated a rather acceptable outcome apart from the comparisons of complication rate between two randomized control studies.

DISCUSSION

Herein, the authors reviewed and explored the optimal management pattern for pediatric 10-20 mm renal stones. This NWA revealed RIRS and mPCNL could render higher SFR without increasing risk of complications compared with ESWL. Although SMP was deemed to be the best choice in our study, the limited source of study and sample size implied the results required to be further validated. In addition, there were still some problems requiring to be underlined for various surgical options.

CONCLUSIONS

ESWL was inferior to RIRS, mPCNL and PCNL for 10-20 mm pediatric renal stones, among which SMP might be the most ideal option associated with the least possibility of complications and the highest probability of stone clearance.

Imaging modalities and treatment of paediatric upper tract urolithiasis: A systematic review and update on behalf of the EAU urolithiasis guidelines panel

BACKGROUND

Prompt diagnosis and treatment of paediatric urolithiasis are required to avoid long term sequelae of renal damage.

OBJECTIVE

To systematically review the literature regarding the diagnostic imaging modalities and treatment approaches for paediatric urolithiasis.

STUDY DESIGN

PubMed, Science Direct, Scopus and Web of Science were systematically searched from January 1980-January 2019. 76 full-text articles were included.

RESULTS

Ultrasound and Kidney-Ureter-Bladder radiography are the baseline diagnostic examinations. Non-contrast Computed Tomography (CT) is the second line choice with high sensitivity (97-100%) and specificity (96-100%). Magnetic Resonance Urography accounts only for 2% of pediatric stone imaging studies. Expectant management for single, asymptomatic lower pole renal stones is an acceptable initial approach, especially in patients with non-struvite, non-cystine stones<7 mm. Limited studies exist on medical expulsive therapy as off-label treatment. Extracorporeal shock wave lithotripsy (SWL) is the first-line treatment with overall stone free rates (SFRs) of 70-90%, retreatment rates 4-50% and complication rates up to 15%. Semi-rigid ureteroscopy is effective with SFRs of 81-98%, re-treatment rates of 6.3-10% and complication rates of 1.9-23%. Flexible ureteroscopy has shown SFRs of 76-100%, retreatment rates of 0-19% and complication rates of 0-28%. SFRs after first and second-look percutaneous nephrolithotomy (PNL) are 70.1-97.3% and 84.6-97.5%, respectively with an overall complication rate of 20%. Open surgery is seldom used, while laparoscopy is effective for stones refractory to SWL and PNL. Limited data exist for robot-assisted management.

CONCLUSIONS

In the initial assessment of paediatric urolithiasis, US is recommended as first imaging modality, while non-contrast CT is the second option. SWL is recommended as first line treatment for renal stones <20 mm and for ureteral stones<10 mm. Ureteroscopy is a feasible alternative both for ureteral stones not amenable to SWL as well as for renal stones <20 mm (using flexible). PNL is recommended for renal stones >20 mm.

A Novel Surgical Technique for Treatment of Renal Stones in Preschool-aged Patients: Initial Experience With Needle-perc

OBJECTIVE

To describe and evaluate our newly developed minimal instrumentation technique, needle-perc, for treatment of preschool-aged patients with renal stones. To the best of our knowledge, this is the smallest endoscopic equipment for percutaneous nephrolithotomy reported thus far.

MATERIALS AND METHODS

Needle-perc was performed in 8 patients using a 4.2-Fr needle to achieve access to the collecting system under ultrasonic guidance alone. The mean patient age was 2.4 years (range, 0-5 years). Five of the 8 patients were boys, while 3 were girls. Six patients had unilateral stones and 2 patients had bilateral stones. Six renal units exhibited single calculus, 2 exhibited staghorn stones, and 2 exhibited multiple stones. The mean calculus size was 1.6 cm (range, 0.8-4.5 cm). Preoperative, intraoperative, and postoperative parameters were analyzed prospectively.

RESULTS

Access was successfully achieved in all patients. Puncturing was fully guided by ultrasound. Five patients underwent needle-perc alone. Two patients were transferred to 16-Fr access because of intrarenal infection and large stone burden. One patient underwent reduction of tract number. The mean operative time was 49.2 minutes (range, 22-75 minutes); mean hemoglobin loss was 5.2 g/L (range, 0-13.8 g/L). The mean postoperative hospital stay was 5 days (range, 3-7 days). Preplaced catheters were kept for 2-3 days to facilitate fragment discharge. Complications occurred in 2 patients: fever >38.5°C. The stone-free rate was 100% at 1 month postoperatively.

CONCLUSION

Our initial data indicate that needle-perc is feasible and safe for preschool-aged renal patients. Further studies are required to define its usefulness in treatment of larger stones.

Outcomes of Ureteroscopy vs Mini-Percutaneous Nephrolithotomy for Pediatric Upper Urinary Tract Calculi: Comparative Nonrandomized Outcomes from Two Tertiary Endourology Referral Centers

Introduction: Pediatric upper urinary tract calculi can be treated by ureteroscopy (URS) or mini-percutaneous nephrolithotomy (mPCNL). We wanted to compare outcomes of URS and mPCNL from two tertiary referral centers that specialized in one of these treatments for pediatric stone disease. Materials and Methods: Data were collected from two tertiary centers for a 10-year period (2010-2019); one center specializing in URS and the other in mPCNL for consecutive patients ≤16 years undergoing either of these minimally invasive interventions. Upper urinary tract stones included stones in the kidney, pelviureteral junction, and proximal ureter, whereas mid or distal ureteral stones were excluded. Data were collected on patient and stone demographics. Outcomes of interest included stone-free rate (SFR) and complication rates. Results: During the study period, 55 patients underwent URS (group 1) and 40 patients underwent mPCNL (group 2). The mean stone size for groups 1 and 2 were 11.4 and 14.5 mm, respectively, whereas twice as many patients in group 1 had multiple stones. The final SFR and complication rates for groups 1 and 2 were 100% and 97.5%, and 5.4% and 12.5%, respectively. Although there were two Clavien II and one Clavien IV complication in the URS group, all five complications in mPCNL group were Clavien I. Conclusions: Our study shows excellent outcomes for upper urinary tract stones with both URS and mPCNL. Although treatment choices should be tailored to patients, each modality carries different advantages and our results reflect that high-volume centers specializing in a particular technique offer best outcomes, and this must also be borne in mind when counseling patients.

Ultrasound-Guided Minimally Invasive Percutaneous Nephrolithotomy is Effective in the Management of Pediatric Upper Ureteral and Renal Stones

Aim: To evaluate the outcome of ultrasound (US)-guided minimally invasive percutaneous nephrolithotomy (MPCNL) in the management of upper ureteral and renal stones in pediatric patients.Methods: We collected data of 112 pediatric patients who were admitted to the xxxx between March 2006 and December 2016 and treated by US-guided MPCNL. Our cohort included upper ureter stones (n = 11), single kidney stones (n = 46), multiple kidney stones (n = 56), and staghorn kidney stones (n = 12).Results: Patients were between 0.5 and 13 years old with stone sizes from 10 to 50 mm. Operation duration ranged from 15 to 195 minutes. On average, the nephrostomy tube could be removed after 3.9 days and patients were discharged after 6.5 days. We found that hemoglobin concentration decreased in 34 patients after surgery by 1 to 37.8 g/L. Using US-guided MPCNL, the initial stone-free rate (SFR) was 86.4% and resulted in a final SFR of 95.2%. However, postoperative complications occurred in 18 patients including > 38.5 °C fever in 17 cases and reactive pleural effusion in one case. Blood transfusion was not required in all cases and no sepsis, kidney loss, ureteral stricture, and adjacent organ injury were observed. Follow-up after an average of 8.5 months showed normal renal function without hydronephrosis. However, recurrence of stones > 4 mm was found in 11 patients.Conclusions: US-guided MPCNL showed an excellent SFR and low complication rate in the management of pediatric patients with upper ureteral and renal stones.

Shockwave lithotripsy for kidney stones as a first-line therapy in children younger than 2 years

BACKGROUND

The incidence of urolithiasis in children has risen worldwide over the last decades with geographical varieties. As pediatric patients begin forming stones earlier in life, they have high risk of recurrence. Extracorporeal shockwave lithotripsy (SWL) is a non-invasive treatment modality that is preferred in the management of pediatric stones. Reports about the safety and efficacy of SWL in patients younger than 24 months are scarce in the literature.

OBJECTIVE

The aim of the study was to evaluate the effectiveness and safety of SWL in patients younger than 24 months. The authors also aimed to assess the validity of the Dogan nomogram in predicting stone-free rates.

STUDY DESIGN

Between January 2009 and March 2019, data of 247 patients younger than 24 months at the time of SWL were retrospectively collected. Analysis was performed on 260 renal units. Success was considered in patients who were completely free of stones after the first session.

RESULTS AND DISCUSSION

The female/male ratio was 103/157, with a median age of 15 (5-24) months, a median stone size of 8 (3-30) mm and a median follow-up period of 7 (3-20) months. Multiple stones and lower calyx stones were observed in 19.6% (51/260) and 23.4% (61/260) of patients, respectively. Complications were detected in 5.8% (15/260) of patients (9 with steinstrasse, 3 with UTI, 2 with vomiting, 1 with hematuria). After the first session, 56.9% (148/260) of patients were stone-free. Forty-six of the failed 112 first sessions underwent second session. A total of 5 patients had a third session. The efficacy quotient was 57%. On univariate analysis, younger age (≤16 months), single stone, small stone size (<10 mm), and non-lower pole location were significant predictors of stone clearance. On multivariate analysis, younger age (=<16 months) and single stone remained significant. The Dogan nomogram score lower than 150 was found to be a good cutoff point to predict better stone clearance (Table).

CONCLUSION

Shockwave lithotripsy is a safe and effective treatment modality in patients younger than 24 months and could be the first option in this particular age-group in whom the other endourological modalities are not always applicable. The Dogan nomogram is reliable in predicting the stone-free rate in this age-group.

Urologic treatment of nephrolithiasis

PURPOSE OF REVIEW

The purpose of this review is to describe the options and recent developments in the urologic treatment of nephrolithiasis in children. The prevalence of nephrolithiasis in children has increased over time. The urologic treatment of nephrolithiasis ranges from observation to medical expulsive therapy with an alpha blocker for a stone in a ureter to a variety of procedures for stone removal.

RECENT FINDINGS

Observation for small, asymptomatic renal stones is a reasonable strategy in children. Medical expulsive therapy with an alpha blocker may have a beneficial effect for passage of ureteral stones in children. Extracorporeal shock wave lithotripsy (ESWL) remains an important treatment for nephrolithiasis in children. Advances in ureteroscopy with clearer digital imaging and single use ureteroscopes have made ureteroscopy more attractive. Percutaneous nephrolithotomy is a more invasive treatment modality but remains a good choice for children with large-stone burdens and instruments are getting smaller. Open or laparoscopic stone surgery should be reserved for unique cases.

SUMMARY

Nephrolithiasis is increasing in children with differing urologic management options depending on the clinical scenario. A shared decision-making process with discussion of risks and benefits should be used to help patients and families choose a treatment option.

Safety and feasibility of percutaneous nephrolithotomy (PCNL) during pregnancy: A review of literature

OBJECTIVE

Management of nephrolithiasis during pregnancy can be challenging because of the potential risks to the mother and fetus. Diagnosis and treatment can be a dilemma owing to the anatomical and physiological changes, besides the limitation in the use of X-rays. The aim of this article was to identify any case series or case reports where percutaneous nephrolithotomy (PCNL) was used as a treatment modality for nephrolithiasis in pregnancy.

MATERIAL AND METHODS

A review of the literature was performed using Medline, EMBASE, CINAHL, and Scopus from 1990 to October 2019. A search was conducted using the following search terms: "urolithiasis," "renal stones," "stone disease," "kidney stones," "pregnancy," "pregnant," "percutaneous nephrolithotomy," "PNL," and "PCNL." The initial search strategy retrieved 52 articles, but after going through them, only 7 were suitable for inclusion in this review.

RESULTS

Overall, seven studies reported regarding 16 patients who underwent PCNL procedure during pregnancy. The patients were aged 18-34 years and had the procedure between 11 and 32 weeks of gestation. Most stones were in the renal pelvis or pelvic-ureteric junction and sized 8-40 mm, with the most common indication for the intervention being refractory pain. Most treatments used ultrasound guidance, and X-ray fluoroscopy was employed only in two cases. No complications occurred to the mother or fetus in any of the case reports, suggesting that PCNL is a safe and feasible treatment for patients with persistent symptoms when conservative treatment has failed.

CONCLUSION

All the reported cases of PCNL achieved stone-free status with no complications. Although PCNL has been evidenced to be safe, it must be performed by experienced endourologists after careful consultation with the obstetricians. Patient counseling and multidisciplinary team decision-making are paramount in such complex scenarios.

Feasibility of dusting and pop-dusting using high-power (100W) Holmium YAG (Ho:YAG) laser in treatment of paediatric stones: results of first worldwide clincial study

Introduction

As the role of paediatric ureteroscopy (URS) for stone disease increases, new methods of stone treatment such as dusting and pop-dusting have emerged. However, outcomes of treatment using these laser settings in paediatric age group is still largely unknown. We aimed to look at the feasibility and outcomes of URS and pop-dusting using a high-power 100W laser for paediatric stone patients.

Material and methods

Outcomes from a prospective stone database were reviewed over a period of 30 months from February 2016–July 2018. All paediatric patients (≤16 years) treated with dusting and pop-dusting were included in our study. Dusting and pop-dusting were performed using Ho:YAG laser with the energy setting ranges of 0.2–0.5 J and 0.5–0.7 J respectively with a frequency of 20–50 Hz.

Results

Twelve patients underwent URS and treatment using this method with mean age of 6.5 years and a male:female ratio of 7:5. The mean and cumulative single stone size was 7.1 mm (3–10 mm) and 11.9 mm (6–40 mm) respectively with half of all patients having multiple stones. Eleven patients were stone free on follow-up with no intra or post-operative complications noted.

Conclusions

Pop-dusting using holmium laser is a new hybrid technique that allows for more efficient dust formation even for hard stones. This is the first clinical study demonstrating the safety and efficacy of this technique in paediatric patients. It is likely there will be wider adoption of these new laser techniques for stone treatment in the paediatric age group.

Outcomes of ureteroscopy (URS) for stone disease in the paediatric population: results of over 100 URS procedures from a UK tertiary centre

PURPOSE

To report the outcomes of paediatric ureteroscopy (URS) for stone disease from a specialist endourology centre in the UK. Ureteroscopy for management of stone disease has increased worldwide and is now being done more commonly in the paediatric age group.

METHODS

Data were analysed retrospectively from a database maintained between April 2010 and May 2018. Consecutive patients ≤ 16 years of age undergoing semi-rigid or flexible URS for stone disease were included. Stone size and stone-free rate (SFR) were routinely assessed using an ultrasound (USS) and/or plain KUB XR. Complications were graded according to the Clavien-Dindo classification and recorded within 30 days post-procedure and readmissions within 90 days after the procedure were also captured.

RESULTS

Over the 8-year period between April 2010 and April 2018, 81 patients with a mean age of 8.8 years (range 18 months-16 years) and a male to female ratio 1:1.1 underwent 102 procedures (1.28 procedure/patient to be stone free). Of the 81 patients, 29 (35.8%) had comorbidities, with 26 (32%) having multiple comorbidities. The mean (± SEM) single and overall stone size was 9.2 mm (± 0.48, range 3-30 mm) and 11.5 mm (± 0.74, range 4-46 mm) respectively, with 22 (27.1%) having multiple stones. Thirty-five (34.7%) had stent in situ pre-operatively. The stone location was in the ureter (26.6%), lower pole (35.4%), and renal pelvis (16.5%), with 22/81(27%) having multiple stones and 21/102 (20.5%) where a ureteral access sheath (UAS) was used. With a mean hospital stay of 1.2 days, the initial and final SFR was 73% and 99%, respectively, and 61/102 (60%) had ureteric stent placed at the end of the procedure. While there were no intra-operative complications, the readmission rate was less than 1% and there were only three early complications recorded. This included a case each of prolonged admission for pain control (grade I), urinary retention (grade II) and post-operative sepsis requiring a brief ITU admission (grade IV).

CONCLUSION

Our study demonstrates that in appropriate setting a high stone-free rate can be achieved with minimal morbidity for paediatric patients. There is potentially a need to factor the increasing role of URS in future paediatric urolithiasis guidelines.

Mini- versus standard percutaneous nephrolithotomy for treatment of pediatric renal stones: is smaller enough?

INTRODUCTION

Miniaturized percutaneous nephrolithotomy (PCNL) has gained increased popularity owing to efforts in recent years to lower peri-operative morbidity while maintaining a high stone-free rate (SFR).

OBJECTIVE

The outcomes of pediatric renal stones treated by mini-PCNL (MPCNL) versus standard PCNL (SPCNL) were retrospectively assessed.

STUDY DESIGN

A retrospective data analysis of 134 consecutive patients younger than 17 years who underwent PCNL between January 2014 and July 2018 was performed. The patients were categorized into two treatment groups depending on the tract size and instruments used. Seventy-five patients were treated by SPCNL using adult instruments via a 22-26 Fr tract, and 59 patients were treated by MPCNL using pediatric instruments via a 16-20 Fr tract.

RESULTS

A total of 134 children (SPCNL = 75; MPCNL = 59) underwent PCNL and subsequent evaluation. Patient demographics and stone characteristics were comparable between the two groups. The mean stone size ranged from 1.9 ± 1.162 cm in the MPCNL group to 2.2 ± 1.424 cm in the SPCNL group, and the overall SFR was 89.5% in the MPCNL group and 94.7% in the SPCNL group. When comparing the common characteristics, no significant difference was found between the two surgical access regarding the mean operative duration, SFR, incidence of peri-operative complications, and the rate of bleeding requiring a blood transfusion. Conversely, the mean postoperative hemoglobin decrease was significantly lower in the MPCNL group relative to the SPCNL group, at 0.354 ± 0.299 g versus 0.568 ± 0.332 g, respectively (P = 0.001). In addition, the mean duration of hospitalization was significantly lower in the MPCNL group than in the SPCNL group, at 1.91 ± 1.154 days compared with 2.41 ± 1.14 days, respectively (P = 0.014).

DISCUSSION

Herein, the authors report the first systematic review of the first center in the locality treating this cross section of patients. This review reveals that the use of these smaller instruments can deliver a strong safety profile while achieving good stone clearance. As an alternative to decreasing the peri-operative morbidity associated with SPCNL, MPCNL can be conveniently used without affecting the outcomes of the procedure. It is a safe and feasible procedure for maximal clearance of stones and should comprise the treatment of choice-regardless of age-for experienced endourologists.

CONCLUSION

MPCNL represents a valuable way of treating simple and complex renal stones in children, with an operative time, SFR, and overall complication rate comparable with those of SPCNL. Mini-PCNL resulted in shorter hospitalization and fewer hemoglobin drops.

Update on Surgical Management of Pediatric Urolithiasis

Urolithiasis has always been a fascinating disease, even more so in children. There are many intriguing facets to this pathology. This article is a nonsystematic review to provide an update on the surgical management of pediatric urolithiasis. It highlights the pros and cons of various minimally invasive surgical options such as extracorporeal shockwave lithotripsy (ESWL), retrograde intrarenal surgery (RIRS), percutaneous nephrolithotomy (PCNL), laparoscopy, and robotics. This article also describes the various intracorporeal disintegration technologies available to fragment the stone, including the newer advancements in laser technology. It also emphasizes the cost considerations especially with reference to the emerging economies. Thus, this manuscript guides how to select the least-invasive option for an individual patient, considering age and gender; stone size, location, and composition; and facilities and expertise available.

Stones in pregnancy and pediatrics

Urinary stone disease is a highly prevalent condition affecting approximately 10% of the population, and has increased in incidence significantly over the past 20 years. Along with this, the rate of stone disease among women and children is also on the rise. The management of stone disease in specific populations, such as in children and during pregnancy can present unique challenges to the urologist. In both populations, a multi-disciplinary approach is strongly recommended given the complexities of the patients. Prompt and accurate diagnosis requires a high degree of suspicion and judicious use of diagnostic imaging given the higher risks of radiation exposure. In general, management proceeds from conservative to more invasive approaches and must be individualized to the patient with careful consideration of the potential adverse effects. However, innovations in endourologic equipment and techniques have allowed for the wider application of surgical stone treatment in these patients, and significant advancement in the field. This review covers the history and current advances in the diagnosis and management of stone disease in pregnant and pediatric populations. It is paramount for the urologist to understand the complexities of properly managing stones in these patients in order to maximize treatment efficacy, while minimizing complications and morbidity.

Effects of visual standard channel combined with visual superfine precision puncture channel or super-mini channel percutaneous nephrolithotomy on multiple renal calculi

Objective

To compare the therapeutic effects of visual standard channel combined with visual superfine precision puncture channel or super-mini percutaneous nephrolithotomy (PCNL) on multiple renal calculi.

Methods

A total of 86 patients with multiple renal calculi were retrospectively analyzed. According to different working channels, they were divided into a visual puncture channel group (visual puncture standard channel combined with visual superfine precision puncture channel, n=38) and a conventional puncture channel group (standard channel combined with super-mini channel, n=48). The two groups were compared in terms of time of channel establishment, surgical time, reduction of hemoglobin, phase I clearance rate of calculi, and surgical complications.

Results

The time of establishing visual/conventional standard channel was (4.5±1.5) min vs. (6.8±1.8) minutes (t=6.326, P=0.000), and the time of establishing visible superfine/super-mini channel was (4.52±0.97) minutes vs. (7.76±1.35) minutes (t=2.017, P=0.000). The surgical time was (92±15) minutes vs. (115±13) minutes (t=26.640, P=0.000). The Phase-I clearance rate was 86.7% (33/38) vs. 87.5% (42/48) (χ²=0.008, P=0.928), the reduction of hemoglobin was (12.21±2.5) g/L vs. (13.22±3.5) g/L (t=2.017, P=0.137), the blood transfusion rate was 13.16 (5/38) vs. 8.33% (4/48) (χ²=0.006, P=0.941), the postoperative fever rate was 7.89% (3/38) vs. 14.58 (7/48) (χ²=0.006, P=0.941), and the hospitalization stay length was (6.5±1.0) vs. (6.6±1.2) (t=0.413, P=0.681). There were no significant differences between the two groups.

Conclusion

Both surgical approaches had high clearance rates of multiple renal calculi, safety, reliability and few complications. However, compared with the conventional puncture channel, the visual one was easy to operate and dramatically shortened the time of establishment, thus being safer and more accurate.

Safety and Efficacy of Day-case Percutaneous Nephrolithotomy: A Systematic Review from European Society of Uro-technology

CONTEXT

Day case or ambulatory percutaneous nephrolithotomy (PCNL) has risen over the last few years with the aim of discharging patients within 24h.

OBJECTIVE

We perform a systematic review of literature to evaluate the outcomes of day-case PCNL surgery.

EVIDENCE ACQUISITION

A Cochrane style search was performed and the following bibliographic databases were accessed: PubMed, Science Direct, Scopus, and Web of Science. This was carried out in accordance with the Preferred Reporting Items for Systematic reviews and Meta-analyses (PRISMA) guidelines. All studies in the English language reporting on PCNL patients discharged within 24h were included.

EVIDENCE SYNTHESIS

Based on the literature search of 97 articles, nine (502 patients) met the inclusion criteria (mean age: 47 yr), with a mean stone size of 20.5mm. The mean operating time was 66min, and over a mean hospital stay of 17.5h, the stone-free rate was 95%. The overall complication rate was 13.5%; the vast majority of these complications were Clavien I-II complications, with a readmission rate of 3%.

CONCLUSIONS

Day-case PCNL is a safe and feasible strategy in carefully selected cases. However, for its success, detailed planning and adherence to surgical protocol are paramount with strict criteria for inpatient admission and a thorough follow-up plan.

PATIENT SUMMARY

Day-case percutaneous nephrolithotomy procedure seems to be a safe procedure with good outcomes, and low risk of complications and readmissions. Detailed preoperative protocol and planning are paramount, with indications for inpatient admission as well as a thorough follow-up plan.