Efficiency of percutaneous nephrolithotomy in pediatric patients using adult-type instruments

Comparison of two percutaneous nephrolithotomy methods for the treatment of pediatric kidney stones: mini-percutaneous nephrolithotomy and standard percutaneous nephrolithotomy

OBJECTIVE

In this study, the aim was to compare the results of mini and standard percutaneous nephrolithotomy (PCNL) for the treatment of pediatric kidney stones.

MATERIALS AND METHODS

Data for 128 patients < 18 years of age who underwent mini and standard PCNL due to pediatric kidney stones were retrospectively examined. Patients were divided into two groups: mini-PCNL (16-20 Fr) and standard PCNL (26 Fr). Surgery time, number of punctures to the pelvicalyceal system, hospital stay, postoperative hemoglobin drop, complications and stone-free status (SFR) were compared between the groups. Additional surgical intervention (double-J stent, ureterorenoscopy, secondary PCNL) performed after the surgery was recorded. The absence of residual stones or < 3 mm residual stones on kidney, ureter and bladder radiography (KUB) and ultrasonography (USG) performed in the third postoperative month were accepted as success criteria.

RESULTS

There were 32 (43.8%) patients in the mini-PCNL group and 41 (56.2%) patients in the standard PCNL group. The mean age was 9.3 ± 4.1 years in the mini-PCNL group and 10.1 ± 5.4 years in the standard PCNL group. Mean stone size in the mini-PCNL group was 2.1 ± 1.2; while for standard PCNL it was 2.3 ± 1.4. The mean surgery time was statistically significantly higher in the mini-PCNL group (p = 0.005). There was no difference between the groups in terms of intraoperative double J stent use, postoperative complications and SFR. A double J stent was inserted in two patients in the mini-PCNL group and in one patient in the standard PCNL group due to urine leakage from the nephrostomy tract in the postoperative period. Although the postoperative hemoglobin drop was found to be significantly higher in standard PCNL (p = 0.001), hematuria and blood transfusion rates were low in both groups. Mean hospital stay was shorter in the mini-PCNL group compared to standard PCNL (3.6 ± 1.2 days vs. 2.5 ± 1.1; p = 0.018).

CONCLUSIONS

Although mini-PCNL has longer surgery time compared to standard PCNL, it should be preferred for the treatment of pediatric kidney stones due to advantages such as similar success and complication rates to standard PCNL, short hospital stay and less postoperative hemoglobin drop.

Is Mini Percutaneous Nephrolithotomy a Game Changer for the Treatment of Renal Stones in Children?

Background

Mini percutaneous nephrolithotomy (MPCNL) is a newer surgical procedure that has changed the management of paediatric renal stones.

Objective

To evaluate MPCNL morbidity and success rates for renal stones as a function of patient age in a paediatric cohort.

Design, setting, and participants

This was a retrospective case series that included 143 consecutive patients younger than 17 yr who underwent MPCNL at our institution between January 2016 and November 2020. The patients were categorised into three different age groups: <6 yr (n = 71, 49.7%), 6–11 yr (n = 44, 30.8%), and 12–17 yr (n = 28, 19.6%). MPCNL was performed in all patients through 16–20Fr tracts.

Outcome measurements and statistical analysis

The stone-free rate, perioperative complications, tract number, operative time, postoperative haemoglobin change, and hospitalisation time were evaluated for each age group.

Results and limitations

MPCNL was performed in 143 paediatric patients (88 boys and 55 girls; mean age 6.53 yr). The mean stone burden (± standard deviation) was 2.096 ± 1.01 cm in group one, 2.05 ± 1.05 cm in group two, and 3.46 ± 19.94 cm in group three; group three was significantly larger (p = 0.001). After a single MPCNL session, 92.42% of patients experienced complete stone clearance. All age groups were similar in terms of stone-free rate (p = 0.82), hospitalisation time (p = 0.94), postoperative haemoglobin change (p = 0.06), and perioperative complications (p = 0.62). However, stone size (p = 0.009), stone complexity (p = 0.001), number of access points (p = 0.03), and operative time (p = 0.009) were higher in the group aged 12–17 yr.

Conclusions

MPCNL is an effective and safe procedure in younger as well as older children. Age should not be considered a limiting factor for MPCNL in children, and MPCNL should be considered the primary option for treating paediatric renal stones when PCNL is indicated.

Patient summary

Our results show that surgical removal of kidney stones through an incision in the skin and using miniaturised instruments is an effective and safe procedure for children.

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.

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.

A comparison of outcomes after percutaneous nephrolithotomy in children and adults: a matched cohort study

INTRODUCTION

Percutaneous nephrolithotomy (PCNL) has surpassed open stone surgery as the operation of choice for large and complex stone burdens (figure). Although the procedure was developed in adults, its principles have been extrapolated to children. There is a paucity of literature comparing outcomes of PCNL in adults and children for similar stone burdens.

OBJECTIVE

The purpose of this study was to evaluate outcomes following PCNL among children and adults with similar stone burdens.

PATIENTS AND METHODS

Data on patient characteristics and outcomes for 2196 consecutive patients undergoing PCNL at a single institution were collected prospectively from January 1992 to July 2013. Thirty-one pediatric patients undergoing 39 PCNLs were identified. Each pediatric PCNL was matched in a ratio of 1:4 to adult PCNLs by year of surgery and stone burden characteristics (staghorn, partial staghorn, number of stones). All PCNLs were performed by two fellowship-trained endourologists who operate on both adult and pediatric patients. Ultrasonic lithotripsy was used primarily. The primary outcome measure was stone-free rate (SFR) at hospital discharge. Secondary outcomes included the need for second-look nephroscopy, length of hospital stay, complication rate, and blood transfusion rate. The Student t test was used for continuous variables and the Fisher exact for categorical variables.

RESULTS

The median age for the pediatric group was 13.9 ± 4.30 years and for the adult group was 55.4 ± 15.1 years. Pediatric patients tended to present with metabolic stones, with no difference in rates of infection stones. No difference was found in SFR at time of hospital discharge (86.1% vs. 86.4%, p = 0.2). More pediatric patients required a second access tract than adult patients (15.4% vs. 4.52%, p = 0.02). There was no significant difference in the need for second-look nephroscopy, length of stay, or complication rates (overall and by Clavien classification subgroup) between both groups. The rates of blood transfusion were low in both groups (0% vs. 0.6%, p = 0.80).

DISCUSSION

There was no difference in primary and secondary outcomes among children compared with adults undergoing PCNL in our study. The outcomes reported in this study were similar to published literature. A limitation of this study is the low number of pediatric patients. However, it is unique to have a single-center study that compares PCNL outcomes in both adult and pediatric patient and accounts for stone burden characteristics.

CONCLUSIONS

Although principles of PCNL were developed in adults, this study affirms the safety and efficacy of PCNL in both pediatric and adult patients.

Ultramini nephrostomy tract combined with flexible ureterorenoscopy for the treatment of multiple renal calculi in paediatric patients

Purpose

To assess the safety and efficacy of an ultramini nephrostomy tract, which we were using for the first time, combined with flexible ureterorenoscopy (URS) in the treatment of pediatric patients with multiple renal calculi.

Materials and Methods

Twenty pediatric patients (age, ≤6 years) underwent ultramini percutaneous nephrolithotomy (PCNL) combined with flexible URS. The group had multiple renal calculi, which were bilateral in 3 cases and were located in a total of 23 sites. The calculi were located in 2 calyces in 10 cases, scattered in more than 2 calyces in 7 cases, and limited to 1 calyx in 3 cases. The average patient age was 37.35 months (range, 14-68 months). The average stone diameter was 2.0 cm (range, 1-3.0 cm). In all patients, an ultramini nephrostomy tract was established under ultrasound guidance (dilated to F10) with simultaneous sheath placement. The flexible URS was placed into the collecting system during holmium laser lithotripsy.

Results

When ultramini PCNL was combined with flexible ureterorenoscopic holmium laser lithotripsy, the complete stone-free rate was 87% (20/23). The average level of hemoglobin decreased to 1.0 g/dL after the operation. No blood transfusions were needed. Levels of blood urea nitrogen, creatinine, and C-reactive protein were not significantly different before and after the operation. The average duration of hospitalization was approximately 4.85 days, and all cases were followed up for 6 to 12 months. No complications were found.

Conclusions

Ultramini PCNL combined with flexible ureterorenoscopic holmium laser lithotripsy is a safe and effective treatment for children with multiple renal calculi.

Percutaneous nephrolithotomy versus open surgery for treatment of staghorn stones in pediatric patients

INTRODUCTION

We compare percutaneous nephrolithotomy (PCNL) and open surgery in the treatment of staghorn stones in children.

METHODS

We retrospectively reviewed the electronic records of children who underwent treatment for staghorn stones between September 2000 and August 2013. They were divided between Group 1 (patients who underwent PCNL) and Group 2 (patients who underwent open surgery). We compared stone-free and complications rates, need for multiple procedures, and hospital stay.

RESULTS

The study included 41 patients (35 boys and 6 girls), with mean age 7.4 ± 3.1 years (range: 2-15). Of these 41 patients, 26 had unilateral renal stone and 15 had bilateral renal stones. The total number of treated renal units was 56: 28 underwent PCNL and 28 underwent open surgery. The complication rate was comparable for both groups (32% for open surgery vs. 28.6%, p = 0.771). Multiple procedures were more needed in PCNL group (60.7% vs. 32% in open surgery, p = 0.032). The stone-free rate was 71.4% after PCNL and 78.6% after open surgery (p = 0.537). A significant difference was observed in shorter hospital stay after PCNL (5 vs. 8.8 days, p < 0.001). Our study's limitations include its retrospective design and relatively small sample size.

CONCLUSIONS

For the treatment of staghorn stones in children, PCNL was comparable to open surgery in complication and stone-free rates. PCNL had the advantage of a shorter hospital stay and open surgery showed a decreased need for multiple procedures.