Percutaneous nephrolithotomy in children in different age groups: data from the Clinical Research Office of the Endourological Society (CROES) Percutaneous Nephrolithotomy Global Study

Shockwaves and the Rolling Stones: An Overview of Pediatric Stone Disease

Urinary stone disease is a common problem in adults, with an estimated 10% to 20% lifetime risk of developing a stone and an annual incidence of almost 1%. In contrast, in children, even though the incidence appears to be increasing, urinary tract stones are a rare problem, with an estimated incidence of approximately 5 to 36 per 100,000 children. Consequently, typical complications of rare diseases, such as delayed diagnosis, lack of awareness, and specialist knowledge, as well as difficulties accessing specific treatments also affect children with stone disease. Indeed, because stone disease is such a common problem in adults, frequently, it is adult practitioners who will first be asked to manage affected children. Yet, there are unique aspects to pediatric urolithiasis such that treatment practices common in adults cannot necessarily be transferred to children. Here, we review the epidemiology, etiology, presentation, investigation, and management of pediatric stone disease; we highlight those aspects that separate its management from that in adults and make a case for a specialized, multidisciplinary approach to pediatric stone disease.

Retrorenal colon in pediatric patients with urolithiasis: Is the supine position for PCNL advantageous?

INTRODUCTION

Percutaneous nephrolithotomy (PCNL) is one of the main approaches for the treatment of large and complex stones in pediatric patients. The patient position for PCNL has been classically divided into prone or supine and the prone position is more commonly used. One of the most feared complications of this surgical technique is colon injury and the objective of this work is to evaluate the incidence of retrorenal colon (RRC) both supine and prone position, in pediatric patients, through radiological images.

MATERIALS AND METHOD

A retrosepctive review was performed of all abdominal CT scans performed in one center, in patients under 18 years since 2017 to 2019. The ideal path for percutaneous puncture was traced in the upper, middle, and lower calyces of both kidneys in the prone and supine positions and contact with the kidney and adjacent organs was evaluated, with a uro-radiologist. Chi-square test and Student's t test were applied.

RESULTS

50 CT-scans were performed on 44 children. Patients had a mean age of 12.6 years and 71.4% were male. Twenty-five scans were performed in the prone and 25 in the supine position. The incidence of RRC for the left kidney (LK) was significantly higher in the lower calyx in prone position than in the supine position, 28% vs 4% (p = 0.049), and the right kidney (RK) presented RRC only in the prone position. The liver was the most frequent retrorenal organ (97.7%) for the RK, with a non-significant difference by position, while for the LK the spleen was the most frequent (61.1%).

DISCUSSION

Colon injury is one of the most morbid complication in PCNL and one of the reasons to perform a CT scan before surgery, on which its incidence appears to be <1% in adults. The present study revealed RRC to be present in three (12%) patients in the supine position and seven (28%) patients in the prone position (p=0.15). These results were slightly higher from those reported in adults (supine: 1.7%-10%; prone: 6.8%-20%), but there are no reports in the literature on this issue to allow appropriate comparison. This is the first study to attempt to assess the incidence of RRC in children according to position.

CONCLUSION

The incidence of RRC for an ideal puncture was significantly higher in the lower calyx of the left kidney in the prone position than in the supine position, and in the right kidney, the RRC only occurred in the prone position.

Comparison between prone and supine nephrolithotomy in pediatric population: a double center experience

PURPOSE

Stone disease in the pediatric age is an increasing issue. Percutaneous Nephrolithotomy (PNL) can be used for larger and complex stones. As in adults it can be performed in the supine or prone position.

METHODS

We retrospectively reviewed two centers' experience in prone and supine PNL in children to analyze its results and complications.

RESULTS

33 patients underwent prone and 19 supine procedures. Patients in the prone group were younger than in the supine, while no significant differences were found in stone burden, access size, operative time or complications. Complications were: 8 and 4 Clavien 1 for the prone and supine group, respectively, one case of urosepsis (4b) in the prone and 2 cases of Clavien 3 in the supine group (double J stent placement for renal colic and ureteroscopy for steinstrasse). Tubeless procedures and mean nephrostomy time were in favor of the supine group, whereas fluoroscopy time and ureteral drainage stay were in support of the prone group. Stone free rate was better in the supine group (83.3 vs 66.6%), possibly reflecting the capability to perform a combined approach in 12 patients (allowing to reach all the calyx with simultaneous anterograde and retrograde access) or younger age in the prone group (13 vs 2 patients ≤5 years), with no differences in stone burden.

CONCLUSIONS

Supine approach seems to guarantee higher stone-free rates. Larger series are necessary to determine what the best technique is in terms of X-ray exposure, operative time and complications.

Outcomes of Mini-Percutaneous Nephrolithotomy in Children and Adolescents: A 10-Year Single-Centre Experience From Kuwait

The current study retrospectively reviewed data for all children and adolescents who underwent mini-percutaneous nephrolithotomy (PCNL) at Ibn Sina Hospital and Sabah Al Ahmad Urology Centre in Kuwait over 10 years. Accordingly, the 40 patients underwent mini-PCNL. Among them, 21 patients (52.5%) had varying degrees of hydronephrosis, with mild to moderate severity accounting for nearly half of them, whereas six (15%) had multiple stones. The median operative time was 54.5 (43.3-64) minutes. Moreover, 11 patients needed flexible ureteroscopy (URS) and double-J (DJ) ureteric stent, and one patient required DJ ureteric stent only. None of the cases developed intraoperative bleeding. The median hospital stay of the included patients was three (2.3-4) days. Residual stone was observed in 11 patients (27.5%), with a median size of 3 (2 to 7) mm. The incidence of postoperative complications was 27.5% (n = 11 patients), with three patients experiencing postoperative bleeding (7.5%) and eight patients developing a fever (20%). All patients had mild postoperative pain. However, no leakage, sepsis, or pelvic injury occurred. None of the patients required revision. In conclusion, mini-PCNL was a safe and effective procedure in children and adolescents with renal stones.

Surgical Technique of Supine Percutaneous Nephrolithotomy in Children

Percutaneous nephrolithotomy (PCNL) in children has become more widely used due to its high efficacy and safety and to the development of miniaturized instruments. A supine approach is promising due to advantages such as better ventilation, reproducibility, and ergonomics. The purpose of the present study is to describe our surgical technique with special considerations in the pediatric population. We used an oblique supine position supported by one silicone gel positioning pad under the hip and another under the ipsilateral flank. The anatomical landmarks used to guide the puncture were the 11th and 12th ribs, the posterior axillary line, and the iliac crest. Initially, a ureteral catheter was introduced endoscopically. A retrograde pyelography was performed to guide the puncture, which was performed using a biplanar technique. A hydrophilic guide wire was then advanced through the needle. Dilation was performed with Alken telescopic dilators until 14 Ch. Fragmentation was performed either with a 13 Ch semirigid cystoscope or a flexible ureteroscope using a holmium: yttrium aluminum garnet (Ho:Yag) laser. We left a double J catheter. Supine PCNL in the pediatric population has comparable efficacy in terms of stone free rate to that of the prone approach as well as less complications. Certain considerations in children are careful padding and placement of the patient close to the edge of the table. Puncture should be guided by ultrasound to reduce radiation exposure. Miniaturized equipment is not widely available, so adaptation of adult equipment for the pediatric population is sometimes necessary.

Ultra-mini-percutaneous nephrolithotomy in flank-free modified supine position versus prone position in treatment of pediatric renal pelvic and lower calyceal stones

OBJECTIVES

To report the safety and efficacy of ultra-mini-percutaneous nephrolithotomy (UMPCNL) in flank free modified supine (FFMS) and prone positions in management of pediatric renal calculi.

PATIENTS & METHODS

This prospective randomized study included 55 pediatric patients with symptomatic renal stones and suitable for ultra-mini-percutaneous nephrolithotomy. They were randomized into two groups. Group A included 28 patients who were treated by UMPCNL in FFMS position (with a pad below the ipsilateral shoulder and buttocks, putting ipsilateral upper limb over the chest, and crossing the extended ipsilateral lower limb over the flexed contralateral one) and Group B included 27 patients treated by UMPCNL in the prone position. In both groups dilatation was done to 13 French sheath allowing the introduction of 6/7.5 French semi-rigid ureteroscope and fragmentation of stones by Ho:YAG laser with a 550-μm fiber laser lithotripter.

RESULTS

The operation time in FFMS position UMPCNL group was significantly shorter than prone position UMPCNL group (84.3±9.87 vs. 99.3±8.75) minutes with p=0.022. There was no significant difference between both groups in terms of stone free rate (89.3% vs. 88.9%), overall complication rate (including transient fever) (21.4% vs. 18.5%), post-operative pain (VAS score) (3.4±0.8 vs. 3.3±0.9), or hospital stay (3.53±0.8 vs. 4.1±1.1) days.

CONCLUSION

Both ultra-mini-percutaneous nephrolithotomy in FFMs and prone positions are feasible, safe and effective in treatment of pediatric renal stones with relatively shorter operative time in FFMS position.

Percutaneous nephrolithotomy in children

INTRODUCTION

The high success rates of percutaneous nephrolithotomy (PCNL) in the clearance of large renal calculi has made it a primary mode of surgical management in adults. Similarly, in children too PCNL has been gaining ground and the indications for the same are on the rise. We retrospectively evaluated the safety and efficacy of this technique, in children below 18 years of age.

MATERIALS AND METHODS

We retrospectively reviewed the inpatient, outpatient records, imaging films of all children with renal stones undergoing PCNL at our hospital.

RESULTS

During the study period, 123 children underwent 129 PCNL at our centre for renal calculi. The mean age was 11.06 years and 87 (70.73%) of the children were males. The size of the stones varied from 15 to 37 mms in the longest diameter. A complete staghorn was noted in six (4.65%) and a partial staghorn in nine (6.97%) children. Supine PCNL was performed in 21 (16.2%) children and remaining 102 (83.7%) children underwent PCNL in prone position. The mean drop in haemoglobin was 1.24 gm%. Stone clearance was achieved in 122 (94.5%) children. Post-operatively four (3.1%) children needed blood transfusions due to excessive bleeding.

CONCLUSIONS

Refinements in percutaneous access techniques, miniaturization of instruments, and technologic advances in energy sources for lithotripsy have led to improvement of outcomes and have lowered the morbidity rates in children following PCNL. It is a safe and effective means of clearing large volumes of renal calculi with minimal morbidity.

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.

Outcome of Mini-Percutaneous Nephrolithotomy in Patients Under the Age of 18: An Experience With 112 Cases

Purpose: Renal calculi are becoming more common among children. Although, extracorporeal shock wave lithotripsy (ESWL) is the first choice in this age group, minimal invasive surgeries, such as percutaneous nephrolithotomy (PCNL), are indicated for some patients. Recently, PCNL devices have become smaller in size with acceptable efficacy and lower complications. We evaluated the outcomes and complications of mini-PCNL (MPCNL) surgery in our referral training centers.

Materials and Methods: Between September 2012 and January 2020, a total of 112 children under the age of 18, who had shown failure of ESWL, and/or their parents refused to do it, underwent MPCNL (15 Fr). The patients' profiles were reviewed for data collection including preoperative and stone data, operation information, and postoperative complications.

Results: Of 112 patients, 69 were boys, and 43 were girls. Their mean age was 8.6 years (14 months to 18 years). Mean stone size was 20 mm (14–34 mm). Seventy-four cases had renal pelvic stone, 22 had pelvis and lower pole, and 16 had staghorn. The mean operation time was 65 min (35–100 min), and mean radiation time was 0.6 min (0.2–1.4 min). Low-grade fever was detected in 14 patients (12.5%). Four patients needed blood transfusion and two had increased creatinine, which improved with conservative management. One patient developed urosepsis that resolved with antibiotic therapy. None of the patients had kidney perforation or other organ injury or death. Early stone-free rate (SFR) after operation was 90.2% (101 patients). Six patients had residual fragment <5 mm, which passed spontaneously in 2 weeks after operation (total SFR 95.3%). Three patients underwent second-look nephroscopy, and ureteroscopy was done for two patients due to migrated stone fragments to the distal ureter.

Conclusion: MPCNL is recommended as a safe alternative option for treatment of the nephrolithiasis in children with good outcome and acceptable complications.

Classification and standardized reporting of percutaneous nephrolithotomy (PCNL): International Alliance of Urolithiasis (IAU) Consensus Statements

BACKGROUND

The aim of this study was to reach a consensus in the classification and standardized reporting for the different types of PCNLs.

METHODS

The RAND/UCLA appropriateness methodology was used to reach a consensus. Thirty-two statements were formulated reviewing the literature on guidelines and consensus on PCNLs, and included procedure specific details, outcome measurements and a classification for PCNLs. Experts were invited to two rounds of input, the first enabled independent modifications of the proposed statements and provided the option to add statements. The second round facilitated scoring of all statements. Each statement was discussed in the third round to decide which statements to include. Any suggestion or disagreement was debated and discussed to reach a consensual agreement.

RESULTS

Twenty-five recommendations were identified to provide standardized reporting of procedure and outcomes. Consensual scoring above 80% were strongly agreed upon by the panel. The top treatment related outcomes were size of sheath used (99.1%) and position for PCNL (93.5%). The highest ranked Outcome Measures included definition of postoperative hospital length of stay (94.4%) and estimated blood loss (93.5%).

CONCLUSIONS

The consensus statements will be useful to clarify operative technique, in the design of clinical trials and standardized reporting, and presentation of results to compare outcomes of different types of PCNLs.

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.

Tubeless PNL can safely be applied to selected patients in pediatric stone disease

OBJECTIVE

The purpose of this study was to compare the results of tubeless percutaneous nephrolithotomy (TPNL) and standard percutaneous nephrolithotomy (SPNL) for the management of nephrolithiasis in children.

MATERIAL AND METHODS

The data for 48 patients aged lesser than 18 years who underwent percutaneous nephrolithotomy (PNL) between January 2010 and June 2018 were reviewed retrospectively. The patients were classified into 2 categories depending on tube placement. A total of 21 patients were treated with TPNL and 27 with SPNL technique. The surgical method employed was selected depending on intraoperative complications. The size of the endoscopic instrument (mini/standard) to be used was decided according to the stone burden and surgeon preference.

RESULTS

A complete stone-free rate (SFR) was achieved in 85.7% (n=18) of the TPNL group and 85.2% (n=23) of the SPNL group (p=0.959). In the TPNL group, two patients with clinically significant stones underwent retrograde intrarenal surgery, and one patient with clinically insignificant residual stone remained under follow-up. In the SPNL group, two patients with clinically significant stones underwent repeat mini-PNL surgery, the stones being fragmented with shock wave lithotripsy in one patient, and 1 one patient with insignificant residual stone remained under follow-up. No significant differences were observed in terms of intraoperative and postoperative complications, mean SFRs, or operative and fluoroscopy times. However, a statistically significant difference was observed in lengths of hospital stay (p<0.001).

CONCLUSION

TPNL is a safe and effective procedure in children. No significant difference was found between TPNL and SPNL in terms of stone clearance; however, patients undergoing TPNL had significantly shorter hospital stays.

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.

Critical Application of Adult Nephrolithometric Scoring Systems to Children Undergoing Mini-Percutaneous Nephrolithotomy

Objective: To evaluate and compare the ability of the Guy's stone score (GSS), the S.T.O.N.E. nephrolithometry, and the Clinical Research Office of the Endourology Society (CROES) nomogram to predict the outcome of mini-percutaneous nephrolithotomy (MPNL) in children, and to identify which of the predictors involved in these scoring systems can separately affect this outcome. Patients and Methods: All children younger than 14 years who had MPNL in our center over a period of 3 years were included prospectively. Bivariate analyses were done to evaluate the associations of the three scoring systems and the predictors composing them with single-session stone clearance and complications. Receiver operating characteristic (ROC) curve analyses of the three scoring systems were conducted to evaluate and compare their abilities to predict the outcomes. Decision curve analyses for the three scoring systems were conducted to evaluate the clinical benefit of using each of them to predict stone clearance. Results: We consecutively enrolled 92 renal units in 89 children with a median age of 9.5 years. Single-session stone clearance was achieved in 76 (82.6%) renal units. Complications occurred with 19 (20.7%) procedures. Stone multiplicity (p = 0.043), staghorn stone (p = 0.007), prior stone treatment (p < 0.001), number of calices involved (p = 0.006), stone burden (p = 0.003), GSS (p < 0.001), S.T.O.N.E. nephrolithometry (p = 0.012), and CROES nomogram (p < 0.001) had significant associations with stone clearance. Only stone attenuation was significantly associated with complications (p = 0.031). For prediction of stone clearance, CROES nomogram demonstrated the greatest area under the ROC curve and the greatest net benefit on decision curve analyses. Conclusions: For children undergoing MPNL, CROES nomogram is the best to predict stone clearance. However, none of the studied scoring systems predicted complications efficiently.

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.

Technique, complications, and outcomes of pediatric urolithiasis management at a tertiary care hospital: evolving paradigms over the last 15 years

BACKGROUND

Despite technological advancements, there is lack of consensus for the standard treatment modalities for pediatric urolithiasis.

OBJECTIVE

The primary objective was to review the management of pediatric urolithiasis over the last 15 years in terms of technical modifications, surgical outcomes, and complications. The secondary objective was to compare the efficacy and outcomes of standard percutaneous nephrolithotomy (PCNL) and mini-PCNL for renal and upper ureteric calculi.

STUDY DESIGN

Medical records of all patients aged <18 years who presented to the authors' tertiary care hospital in northern India between August 2003 and December 2018 were reviewed retrospectively. Before 2010, all PCNLs performed were standard PCNL, whereas after 2010, most PCNLs performed were mini-PCNL. Thus, the patients were divided into two groups: group A (patients up to 2010) and group B (patients after 2010). These were compared for the type of treatment, success rate, and complications. The outcomes of surgical management of lower ureteric and vesical calculi were also reviewed.

RESULTS

During this period, there were 580 children with urolithiasis (677 stone sites). There were 265 patients (321 stone sites) in group A and 315 patients (356 stone sites) in group B. The median age was seven years (range: 3-18 years). The most common location of calculus was the collecting system of the kidney (n = 398, 58.8%). A total of 175 stone sites (25.8%) were located in the ureter. Urinary bladder calculi were seen in 43 (6.4%) patients. Multiple stones were seen in 61 sites (9.0%). A total of 115 patients in group A underwent standard PCNL, whereas in group B, nine patients underwent standard PCNL and 129 underwent mini-PCNL. Group B had a significantly higher stone clearance rate for mini-PCNL (P < 0.001). Minor complications (grades 1 and 2) accounted for a majority of overall complications in both groups (87.5% in group A and 94.9% in group B).

DISCUSSION

Mini-PCNL is an excellent option for renal calculi in children as it offers dual advantages of improved stone clearance and reduced major complications such as bleeding. Ureteroscopic lithotripsy has been established as the standard for small lower ureteric calculi.

CONCLUSION

For renal and upper ureteric calculi, mini-PCNL has evolved as standard technique with a high stone-free rate and minimum complications compared with standard PCNL. Extracorporeal shockwave lithotripsy and ureteroscopic lithotripsy (URSL)/retrograde intrarenal surgery are acceptable alternatives for smaller stone burden. For lower ureteric and vesical calculi, retrograde approaches such as cystolithotripsy and URSL have now become the standard of care.

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.

Percutaneous Nephrolithotomy in Children: Analysis of Nationwide Hospitalizations and Short-Term Outcomes for the United States, 2001-2014

OBJECTIVE

To describe population-wide utilization rates and outcomes of percutaneous nephrolithotomy (PCNL) in the management of pediatric upper urinary tract calculi (UUTC).

PATIENTS AND METHODS

Patients <18 years with a diagnosis of UUTC, who underwent PCNL between 2001 and 2014 were identified from the National Inpatient Sample database. Annual PCNL rates, based on the at-risk population for each year, were estimated, and change in utilization rate was analyzed using negative binomial regression. Perioperative outcomes, hospital length of stay (LOS), and costs were determined; continuous and categorical variables were analyzed using nonparametric tests and Chi-squared tests, respectively. Trends tests and multivariable analyses (MVAs) were also performed where appropriate.

RESULTS

An estimated 3206 pediatric PCNL procedures were performed. Mean annual PCNL rate increased significantly relative to 2001 (incidence rate ratio = 1.40; 95% confidence interval 1.15-1.71, p = 0.001). Proportion of PCNL as a fraction of all inpatient surgical procedures for UUTC also significantly increased over time, from 15.7% in 2001 to 26.4% in 2014 (p < 0.0001). Complications overall occurred in 20.7% of cases, with a significantly rising rate over time period (p < 0.0001). Complication rates were similar across hospital types and geographic regions. Median hospitalization cost was significantly higher for the West than for each of the other regions (p < 0.05 in each case). Median LOS was also highest for the West (4 days vs 3 days for each of the other regions). In MVA, significant predictors of both increased LOS and costs included black race, comorbidities of hypertension, diabetes, coagulopathy and neurologic disease, hospitalization in the South, and presence of complications. Race, gender, comorbidities, and treatment year were among the predictors of complications.

CONCLUSIONS

PCNL utilization in the management of pediatric UUTC has significantly increased since 2001, with an associated increase in complication rates, although major complications were uncommon. Regional variations in costs and LOS were evident.

Nationwide Readmission Rates Following Percutaneous Nephrolithotomy: Does Age Matter?

Introduction/Objectives: Despite minimal evidence that evaluates the effect of age on percutaneous nephrolithotomy (PCNL) morbidity, pediatric and elderly patients are considered high-risk groups. Our objective was to assess the effect of the extremes of ages on PCNL readmission and postoperative complication rates. Methods: We identified all PCNL encounters in the 2013 and 2014 Nationwide Readmission Database. Encounters were divided into five age groups: pediatric (<18 years old), young adult (18-25 years old), adult (26-64 years old), geriatric (65-74 years old), and elderly (≥75 years old). Weighted descriptive statistics were used to describe population demographics. We fit an adjusted weighted logistic regression model for 30-day readmission and complication rates. Results: We identified 23,357 encounters. Testing average effect of pediatric and elderly encounters to all other age groups did not reveal a difference in odds for 30-day readmissions, but did result in increased odds for 30-day GU readmissions (odds ratio: 17.7 [95% confidence interval (CI): 2.65-118.9]; p = 0.003). Compared to all other age groups, elderly encounters had 7.5 (95% CI: 2.5-22.7; p = 0.0004) times the odds of a 30-day readmission and 68.3 (95% CI: 29.1-160.4; p < 0.0001) times the odds of a postoperative complication. Conclusions: When comparing the average effect of the extremes of ages to all other age groups, we did not find evidence to suggest a difference in odds for 30-day GU readmissions, but did find increased odds for complications. Further examination revealed that PCNL encounters of elderly patients had significantly increased odds for both readmission and complications, whereas PCNL encounters of pediatric patients did not.

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.

Factors predicting postoperative febrile urinary tract infection following percutaneous nephrolithotomy in prepubertal children

BACKGROUND

Predictive tables and scoring systems can predict stone clearance. However, there is a paucity of evidence regarding the prediction of complications during percutaneous nephrolithotomy (PCNL), particularly in children, which remains under-researched. To our knowledge, no studies have evaluated the risk factors for febrile urinary tract infection (FUTI) after pediatric PCNL.

OBJECTIVES

To assess the predictive factors of FUTI in prepubertal children after PCNL and determine whether any prophylactic cephalosporins are superior for decreasing the FUTI rate.

STUDY DESIGN

Data from 1157 children who underwent PCNL between 1991 and 2012 were retrieved from the multicenter database of the Turkish Pediatric Urology Society. Children >12 years of age were excluded, leaving 830 children (364 girls, 466 boys). Data were analyzed according to the presence of FUTI and compared between the FUTI and non-FUTI groups.

RESULTS

Mean age was 6.46 ± 3.38 years. Twenty-nine (3.5%) children had FUTI which was confirmed by urine culture. FUTI occurred more frequently in young children (5.5%) than school-age children (2.4%). In univariate analysis, there were significant differences between the FUTI and non-FUTI groups regarding age, cephalosporin subgroup (first, second and third generation cephalosporin), side of PCNL, staghorn stones, tract size, operative time, postoperative ureteral catheter usage, perioperative complications (SATAVA), and blood transfusion. Multivariate analysis revealed that age, side of PCNL, staghorn stones, tract size, operative time, and blood transfusion were independent predictors of FUTI.

DISCUSSION

The smaller tract size could cause FUTI with poor fluid drainage that may lead to elevate renal pelvic pressure and trigger bacteremia-causing pyelovenous backflow. Filling the calyx and renal pelvis by a staghorn stone and the resulting obstruction of fluid drainage may elevate intrarenal pelvis pressure. Longer operative time is likely to increase renal pelvic pressure over longer periods, which may account for FUTI after pediatric PCNL.

CONCLUSIONS

Younger age, right-sided PCNL, staghorn stones, mini-PCNL, longer operative time, and blood transfusion are risk factors for FUTI. First-, second-, and third-generation cephalosporins are equally effective for prophylaxis in prepubertal children undergoing PCNL.

Trends of intervention for paediatric stone disease over the last two decades (2000-2015): A systematic review of literature

OBJECTIVE

To ascertain the publication trends of interventions for paediatric kidney stone disease (KSD) we conducted a systematic review of literature over the last 16 years.

PATIENTS AND METHODS

With a rise of paediatric KSD and related interventions, a systematic review using PubMed was done over the last 16 years for all published papers on 'Paediatric stone disease intervention - ureteroscopy (URS), shockwave lithotripsy (SWL), percutaneous nephrolithotomy (PCNL), open stone surgery, and laparoscopic stone surgery'. The search was limited to English language articles with a published abstract, whilst case reports, animal and laboratory studies, were excluded. We also analysed the data in two time periods, period-1 (2000-2007) and period-2 (2008-2015).

RESULTS

During the last 16-years, 339 papers were published on paediatric stone disease intervention on PubMed. This included papers on URS (95), PCNL (97), SWL (102), open stone surgery (34) and laparoscopic stone surgery (11). During period-1 and period-2 there were 30 and 65 papers on URS, 16 and 81 papers on PCNL, 33 and 60 papers on SWL, nine and 25 papers on open surgery, respectively. When comparing the two periods, there were 92 published papers for all interventions in period-1 and this had risen almost threefold to 247 papers in period-2.

CONCLUSIONS

Our systematic review shows that intervention for KSD in the paediatric age group has risen over the last 8 years. Whilst URS, SWL, open surgery and laparoscopic surgery have all doubled, PCNL has risen fivefold reflecting an increase in the new minimally invasive PCNL techniques.

Use of Ultrasound in Pediatric Renal Stone Diagnosis and Surgery

Pediatric urolithiasis is on the rise globally and incidence rates have risen by 6-10% annually over the past couple of decades. Given the increasing incidence, high likelihood of recurrence, and long life expectancy of children, the use of ionizing radiation in the diagnosis, management, and follow up of pediatric urolithiasis has been scrutinized recently and many institutions and organizations have emphasized the use of non-ionizing imaging modality such as ultrasound. This review examines the use of ultrasound in the diagnosis and treatment of pediatric urolithiasis. Specifically, the role of ultrasound in shockwave lithotripsy, percutaneous nephrolithotomy, and, more recently, ureteroscopy will be examined.

STPEDISET: A novel innovation for percutaneous nephrolithotomy in children

PURPOSE

The aim of this study was to report the outcomes of PCNL in patients in whom the Short and Thin Pediatric Set (ST PEDISET) had been used.

METHODS

Data from 21 patients (11 boys and 10 girls) who underwent PCNL for renal stones using the ST PEDISET between April 2013 and February 2015 were analyzed retrospectively. The patients were evaluated by plane radiography and USG after surgery.

RESULTS

In total 21 children (11 boys and 10 girls) with a median age of 13months (range 5months to 4years) who underwent PCNL were included in the study. The median stone burden was 16mm (range 10-36mm). The success rate was 85.7%. Sixteen patients (76.2%) were stone free and two patients (9.5%) had clinically insignificant residual fragments (CIRF). The median length of hospital stay was 4days (range 2-9days).

CONCLUSIONS

The data of this study clearly show that the ST PEDISET is safe, effective and ergonomic for percutaneous nephrolithotomy in preschool-age children. This study indicates the need for randomized trials on larger cohorts to confirm these findings, and thus improve the surgical procedure.

Percutaneous nephrolithotomy in pediatric age group: Assessment of effectiveness and complications

Management of kidney stone disease in pediatric population is a challenging condition in urology practice. While the incidence of kidney stone is increasing in those group, technological innovations have conrtibuted to the development of minimally invasive treatment of urinary stone disease such as mini-percutenous nephrolitotomy (mini-PCNL), micro-PCNL, ultra mini-PCNL. In this review we tried to evaluate the effect of new teratment techniques on pediatric kidney stones.

Management of stone disease in infants

Evaluating and treating renal stone disease in infants are technically challenging. In this study, we evaluated the surgical treatment of renal stones in children under 1 year of age. We retrospectively reviewed the records of patients under 1 year old who were treated with ESWL, endourological or open surgical procedures for renal stone disease between January, 2009 and December, 2012. The patients' age, gender, stone size, stone location and number, complications, stone-free status, and postoperative complications were recorded. 19 of 121 infants with a mean age of 10.2 ± 3.07 months were treated with surgical procedures. Six (75%) of eight cystinuria patients required a surgical intervention. Retrograde endoscopic management was performed in thirteen patients (63.4%) as an initial surgical approach. There were three major (15.7%) complications. The rate of open surgical procedures was 31.6% (6 of 19 infants). The cutoff value of stone size for open surgery was 10 mm. There was a significant relationship between the conversion to open procedures and stone size, stone location, and symptom presentation especially the presence of obstruction (p < 0.05). After repeated treatments, the stone clearance rate of RIRS reached 84.6%. Retrograde intrarenal surgery is an effective and safe treatment method for renal stones in infants and can be used as a first-line therapy in most patients under 1 year old. This is especially important if an associated ureteral stone or lower pole stone that requires treatment is present and for patients with cystinuria, which does not respond favorably to ESWL.

Supine pediatric percutaneous nephrolithotomy (PCNL)

INTRODUCTION/BACKGROUND

Many authors reported their experience with supine PCNL in adult population comparing the outcome with prone PCNL and they found that the stone free rate and the operative time were in favor of prone PCNL with a lower patient morbidity among patients with supine PCNL. This encouraged us to perform supine PCNL in pediatric population.

AN OBJECTIVE

In this study we evaluated the safety and efficacy of supine PCNL in pediatric population.

STUDY DESIGN (SUBJECTS/PATIENTS/MATERIALS/METHODS)

Between April 2011 and February 2014 a total of 27 children (6 girls and 21 boys) presented with renal calculi. The stones were single pelvic stone in 14 cases, pelvic stone with lower calyceal stones in 7 cases and pelvic stone with upper calyceal stones in 6 cases. The mean stone size was 32 mm (range 20-47 mm). All patients were managed with supine PCNL performed by a single surgeon. Marking the posterior axillary line in standing position before the operation is a mandatory initial step. The patients were placed in supine position with elevation of the ipsilateral shoulder and hip by means of two bags one underneath the shoulder and the other underneath the hip to widen the operative field. The technique was performed using a sheathless 19 fr. Richard wolf rigid nephroscope after acute tract dilation by amplatz dilators. Complications (intraoperative and postoperative) and stone free rate rates were reported.

RESULTS

A single lower calyceal access was used in all cases through which we could successfully remove even the upper calyceal stones. Kinking of the guide wire during tract dilatation were encountered in 4 cases and the guide wire was successfully exchanged using a small Teflon dilator in 2 cases while ultrasonographic guided lower calyceal repuncture was done in 2 cases. The average operative time (from the beginning of the puncture trial to nephrostomy tube insertion) was (41 ± 15) min. The operation was successfully completed as planned in all cases with two cases of intraoperative complications (one case of pelvicalyceal system perforation and another case of intraoperative bleeding and blood transfusion). The initial stone free rate was (92.5%). Postoperative complications was reported in the form of 2 cases of fever that respond to medical treatment for 72 h.

DISCUSSION

The main advantages of supine pediatric PCNL is that it is comfortable for the surgeon, the anesthetist and the child. The main disadvantages of supine pediatric PCNL is that it is not familiar for most urologists and small field of operation. The short outcome of our study is the small number of cases and the lack of comparative study with prone pediatric PCNL.

CONCLUSIONS

Pediatric supine PCNL is a safe and effective method for management of pediatric renal stones. It carries the advantages of easily upper calyx access through the lower calyceal tract, low incidence of fluid absorption or hypothermia and easy anesthesia monitoring. However a larger number of cases are needed to be evaluated.

Flank-free Modified Supine Percutaneous Nephrolithotomy in Pediatric Age Group

OBJECTIVE

To evaluate the safety and efficacy of pediatric percutaneous nephrolithotomy (PCNL) in the flank-free modified supine position (FFMSP). PCNL in the supine position is increasingly and successfully used in pediatric age group. Different modifications of supine positions have been described; however, the best supine position is not well established and remains a matter of debate.

PATIENTS AND METHODS

This prospective study included 22 children presenting with single renal pelvis stone (2-3 cm) in the period between May 2012 and April 2014. Diagnosis was set by plain x-ray and computed tomography in all patients. PCNL was performed with the patients placed in the FFMSP. The operative time and hospital stay were estimated. The outcome and any perioperative complications or conflicts were recorded.

RESULTS

The study included 22 children (15 boys and 7 girls) with a solitary renal pelvis stone. Mean ± standard deviation age of the patients was 9.5 ± 3.2 years (range, 3-15.5 years). Stone length, operative time, and hospital stay had mean ± standard deviation of 2.4 ± 0.23 cm, 65.1 ± 18.7 minutes, and 4.4 ± 0.9 days. Stone-free rate was 90.9% after 1 session of PCNL. One patient (4.5%) needed a second-look PCNL. Shock wave lithotripsy was performed for another patient. Postoperative fever occurred in 4 patients (18.2%). One patient received postoperative blood transfusion. Postoperative transient urinoma occurred in 2 patients (9.1%).

CONCLUSION

PCNL in pediatric age group via FFMSP was proved to be safe and effective in management of renal pelvis stones of size 2-3 cm. It provides stone clearance rate comparable with that reported of conventional PCNL in the prone position.

Percutaneous nephrolithotomy and ureteroscopy in children: evolutions

The increasing incidence of pediatric stone disease has coincided with significant advances in technology and equipment, resulting in drastic improvements in management. Miniaturization of both ureteroscopes and percutaneous nephrolithotomy (PCNL) equipment has facilitated access to the entirety of the urinary tract and has made ureteroscopy a first-line therapy option along with shock-wave lithotripsy for kidney and ureteral stones. Advances in PCNL have decreased patient morbidity while preserving stone clearance rates. In this review, the advances in operative approach for ureteroscopy and PCNL in children and its applicability to current surgical management of pediatric stone disease are discussed.

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.

Percutaneous nephrolithotomy in children: A preliminary report

Objectives:

The recurrence of pediatric nephrolithiasis, the morbidity of repeated open surgical treatment as well as our experience in percutaneous nephrolithotomy (PNL) in adult patients, all derived us to shift to PNL for managing renal stones >1.5 cm in pediatric patients. Our aim of this study is to evaluate the safety and efficacy of PNL in pediatric patients.

Materials and Methods:

During the period of the month between May 2011 and April 2013, 38 children (47 renal units) underwent PNL for renal stones 1.5-5 cm in length. Patient demographics, stone characteristics, and clinical outcome were prospectively studied. Data of those who underwent conventional and tubeless PNL were compared. Median follow-up period was 12 months (range: 6-24).

Results:

The median age at presentation was 8-year (range: 3-12). The operative time ranged from 30 to 120 min (median 90). Overall stone clearance rate was 91.5% after single PNL. The median hospital stay was 3 days. Auxiliary procedures were successful for the remaining 4 patients (nephroscopic clearance in one and shockwave lithotripsy in 3). Tubeless PNL was performed in 17 renal units with a comparable outcome to conventional ones. The perioperative complications were noted in 5/47 (10.6%) of all procedures (Clavien Grade II in 4 and Clavien Grade IIIa in 1) and were managed conservatively.

Conclusions:

Percutaneous nephrolithotomy for renal stones in pediatric patients is safe and feasible if performed by a well-experienced endourologist. Tubeless PNL is a better choice for children.

Minimally invasive percutaneous nephrolithotomy in children less than three years of age: five-year experience in 234 cases

OBJECTIVE

The treatment of infant renal stones is still a huge challenge to the urologist. The present study aimed to evaluate the safety and efficiency of the minimally invasive percutaneous nephrolithotomy (MPCNL) method as a treatment for infant renal stones, and also to analyze the specific techniques and related complications of the procedure.

PATIENTS AND METHODS

From January 2008 to December 2012, 234 cases (72 girls and 162 boys, mean age 15.8 months, range 5-36 months) aged under 3 years and treated with MPCNL for renal stones were analyzed retrospectively. 125 cases were younger than 12 months, 67 cases were between 13 and 24 months and 42 cases between 25 and 36 months. The indications for MPCNL were (1) stone over 1 cm(2), (2) hydronephrosis and (3) recurrent urinary tract infection. An initial percutaneous access to the targeted renal calyx was obtained through an ultrasound-guided peripheral calyceal puncture. Stones were fragmented by a holmium laser with a pediatric nephroscope via 14-F tract.

RESULTS

All the procedures were performed by single tract, and totally 247 tracts were established, including 245 14-F tracts, 1 16-F tract and 1 12-F tract, respectively. The stones were located in the left kidney (n = 91), right kidney (n = 105) and in both kidneys (n = 28), respectively. Regarding the puncture point, in 228 cases it was in the 12th subcostal space and in 19 cases in the 11th intercostal space. The distribution of target puncture calyx and the subsequent residual calculi were as follows: 39 cases in the upper calyx with 2 cases of stone residual, 148 in the middle calyx with 3 stone residuals, and 60 in the lower calyx with 2 stone residuals, respectively. As a result, completely stone-free state was achieved in 240 kidney units (97.2%). The mean operating time was 32.5 min. None of the patients required blood transfusion and no septic shock occurred after operation. A large quantity of washing fluid was infiltrated into the abdominal cavity in 3 cases.

CONCLUSION

Using a single tract ≤14 F, MPCNL is a safe and effective procedure in the management of renal stones in infant less than 3 years old.

Comparison of children versus adults undergoing mini-percutaneous nephrolithotomy: large-scale analysis of a single institution

Objective

As almost any version of percutaneous nephrolithotomy (PCNL) was safely and efficiently applied for adults as well as children without age being a limiting risk factor, the aim of the study was to compare the different characteristics as well as the efficacy, outcome, and safety of the pediatric and adult patients who had undergone mini-PCNL (MPCNL) in a single institution.

Methods

We retrospective reviewed 331 renal units in children and 8537 renal units in adults that had undergone MPCNL for upper urinary tract stones between the years of 2000–2012. The safety, efficacy, and outcome were analyzed and compared.

Results

The children had a smaller stone size (2.3 vs. 3.1 cm) but had smilar stone distribution (number and locations). The children required fewer percutaneous accesses, smaller nephrostomy tract, shorter operative time and less hemoglobin drop. The children also had higher initial stone free rate (SFR) (80.4% vs. 78.6%) after single session of MPCNL (p<0.05); but no difference was noted in the final SFR (94.7% vs. 93.5%) after auxiliary procedures. The complication rate (15.6% vs. 16.3%) and blood transfusion rate (3.1% vs. 2.9%) were similar in both group (p>0.05). Both groups had low rate of high grade Clavien complications. There was no grade III, IV, V complications and no angiographic embolization required in pediatric group. One important caveat, children who required multiple percutaneous nephrostomy tracts had significant higher transfusion rate than in adults (18.8% vs. 4.5%, p = 0.007).

Conclusions

This contemporary largest-scale analysis confirms that the stone-free rate in pediatric patients is at least as good as in adults without an increase of complication rates. However, multiple percutaneous nephrostomy tracts should be practiced with caution in children.

Percutaneous nephrolithotomy in high-risk patients: a single-center experience with more than 350 cases

PURPOSE

To assess the surgical outcomes and peri- and postoperative complications following percutaneous nephrolithotomy (PCNL) in high- and low-risk patients according to the American Society of Anesthesiologists (ASA) score.

MATERIALS AND METHODS

We reviewed the patient records of 2,281 cases older than 18 years who had undergone PCNL in the 3 previous years. The patients were divided into two groups: a low-risk group (ASA score 1, 2: 1,922 cases) and a high-risk group (ASA score 3, 4: 359 cases).

RESULTS

Analysis of the location and size of the stone, number and type of access, surgical approach, post-PCNL serum hemoglobin and decrease in glomerular filtration rate revealed no significant difference between the two groups. The stone-free rate was similar in both groups and the hospital stay in the high-risk patients was significantly greater than in the low-risk cases. 95% of low-risk and 91% of high-risk cases had surgical complications compatible with grade ≤II (Clavien system) and overall distribution of different grades of surgical complications was similar between the two groups (p = 0.177).

CONCLUSION

Success rate and surgical complications of PCNL in high-risk patients were comparable to low-risk patients. It seems that PCNL may be a safe and effective procedure even in high-risk patients.