Ukrainian Journal of Nephrology and Dialysis

. The incidence of kidney stones in children has increased in recent years. Unlike adults, the treatment of pediatric kidney stones is more difficult because of the size of the stones and the high risk of recurrence. The present study aimed to evaluate the management of pediatric kidney stones with percutaneous nephrolithotomy in general and with both types of percutaneous nephrolithotomy (PCNL). Methods. This retrospective cross-sectional study was conducted at Al-Safeer Al-Imam Al-Hussein Hospital from November 1, 2019 to October 31, 2021. A total of 90 children with kidney stones were divided into 45 with tubular PCNL and 45 with tubeless PCNL. The children were followed up for at least six months postoperatively. Results. After PCNL, only 4 children were not stone-free and no injury was noted, whereas sepsis was noted in only one child. Renal status after PCNL was stable renal function in 97.8% of children and improved renal function in 2.2% of children, while no deterioration of renal function was noted. The characteristics of the children, the characteristics of the surgical procedure (except access), and the results of PCNL were not significantly different among the different types of PCNL Conclusion. PCNL in both variants (with and without tubing) is a safe and effective surgical option in the treatment of children with renal stones.

nephrolithiasis are identified incidentally [11]. In addition to clinical features, laboratory and x-ray findings, the diagnosis of pediatric renal stones is based on ultrasound examination [12]. Exposure to high radiation in the diagnosis and management of renal stones must be avoided as possible. After medical conservative therapy of children, the surgical option is considered the treatment of choice. The common treatment choices for pediatric renal stones are extracorporeal shockwave lithotripsy, retrograde intrarenal surgery with ureteroscopy, and percutaneous nephrolithotomy (PCNL). The PCNL is commonly indicated in staghorn calculus, infected large renal stones and renal stones with anatomical abnormalities [13].
PCNL is associated with a stone-free rate of 70-97% [14], with a high success rate in stone size less than 2 cm [15]. Although the high stone-free rate of PCNL in children, many complications are reported with longer hospital stays [16]. Stone recurrence in children is widely reported after management with a rate of 19-34% rate after three years [17]. Preventive strategies like routine monitoring, high fluids intake, dietary modification, and medicines are required after PCNL in children with renal stones to avoid recurrence [18]. The first report of PCNL in children was in the United States in 1985 and from that date, the use of PCNL in the management of pediatric nephrolithiasis was slow. Recently with advances in medical and surgical technologies, the PCNL is replacing open surgery becoming an alternative to extracorporeal shockwave lithotripsy and ureteroscopy [19]. Conventionally followed by the application of a nephrostomy tube and ureteral stent tube for adequate drainage preventing and assessing bleeding, and allowing the surgeons to second look for residual stones in the kidney. This method is accompanied by high discomfort and pain resulting from renal fistula and the long presence of ureteral stent [20]. For these reasons, many physicians and urologists revealed that tubed PCNL for patients with renal fistula leads to pain, discomfort, and long hospital stay as compared to tubeless PCNL is dependent on not placing nephrostomy and not accompanied by dangerous bleeding complications [21,22].
After the advancement of PCNL in the last decades, the routine tubed technique was under question, with the advancement of significance for the tubeless technique [23]. Nephrostomy placement or displacement is related to many complications like discomfort, pain, infection, urinary leak, hemorrhage, and longer hospital stays [24]. To avoid or lower these adverse effects of the tubed technique, the tubeless PCNL is developed by inserting a double J ureter stent after the percutaneous nephrolithotomy [25]. In children, the tubeless PCNL showed similar effectiveness and outcomes reported for routine tubed PCNL with lower disadvantages of pain and discomfort reported for the latter technique [26,27]. Although the advantages of tubeless PCNL are all over the world, this technique is slowly disseminated till now [28].
PCNL is the common surgical treatment option for the management of renal stones for adults and children in Iraq [29,30]. The tubed PCNL is widely used in the management of pediatric nephrolithiasis in Iraq [30], however, recent advances by a little number of Iraqi surgeons revealed an appropriate efficacy and lower disadvantages of PCNL for adults and children by the implementation of the tubeless technique [31,32]. For that, more research are required nationally and internationally to encourage physicians and surgeons to explore the advantage and disadvantages of the tubeless technique.
The present study aimed to evaluate the management of pediatric kidney stones with percutaneous nephrolithotomy in general and with both types of percutaneous nephrolithotomy Materials and methods. The present project was a retrospective cross-sectional study implemented in the Safeer Al-Imam Al-Hussein Hospital in Karbala governorate-Iraq through the period of two years from 1st of November 2019, to 31st of October 2021. The studied population was children with kidney stones admitted to the hospital. Inclusion criteria were pediatric-age patients (≤5 years) with kidney stones of size more than two centimeters. Exclusion criteria were older age children, positive urine culture, kyphoscoliosis, coagulopathy, and parents who refused to enrollment of children in the study. The study ethics were implemented regarding the Helsinki Declaration by documented agreement of parents, approved by the ethical committee in Medical College of Karbala University and hospital authority in addition to managing future complications. A sample of ninety children with kidney stones was enrolled in the present study and divided into two groups according to PCNL techniques (45 children operated with tubed PCNL and 45 children with tubeless PCNL).
Information on children was collected directly by the researcher through a prepared questionnaire according to previously published data [21][22][23] The diagnosis of kidney stones was done by the researcher according to history, clinical examination, laboratory, and ultrasound findings. The surgery of PCNL was done by the researcher after the approval of parents and most of the children were generally anesthetized. The children were set in lithotomy position first and the cystoscopy was placed then we put 3 fr. ureteric catheter under fluoroscopy then change position to prone position and start by injecting contrast in the catheter and using needle 18G by bull eye technique then insert guidewire and sequential dilatation did then use 12fr. nephroscope and we use the pneumatic device to destruct the stones and extract them by active grasper after completing the stones we put 3 or 4 fr Dj stents. The nephrostomy tube was put in the PCS if there is bleeding happened or during a preoperative period. Bacteremia was not resolved by antibiotics or if an injury to the pelvis happened.
The children were followed up for six months postoperatively by a second visit to a clinic or by phone calling to assess the outcomes of PCNL for each study group and manage any complications. The children's information was entered and interpreted statistically by the SPSS program-26. Data were presented as mean (M) and standard deviation (SD) and compared with the Student's test. The difference in group proportions was compared with the χ2 test. Suitable statistical tests for data were implemented accordingly and a p-value of ≤0.05 was significant.
Results. In this study, ninety children with kidney stones were enrolled with a mean age of four years; the age of 2-3 years represented 31.1% of children, and the age of 4-5 years represented 68.9% of them. Male children with renal stones were more than females (61.1% vs. 38 The PCNL was the treatment of choice for the studied children with renal stones; 50% of them by tubed PCNL and the other 50% of them by tubeless PCNL. PCNL approach used was commonly through the upper pole (76.7%); followed by; the middle pole (17.8%), lower pole (4.4%), and multiple poles (1.1%). The main access was single (97.8%) or addi-tive tract (2.2%). No blood transfusion and hepatitis infection were reported. Anomalies of the kidney detected surgically were only horseshoe kidney (3.3%) and double moiety (1.1%). General anesthesia was implemented for 98.9% of children who had undergone PCNL, while neuroaxial anesthesia was used for only one child ( Table 2). A post-PCNL stone-free was detected in 95.6% of children and only four children had no stone free. The post-PCNL injury was not reported, while the sepsis was detected in only one child postoperatively.
Post-PCNL renal status was a stable renal function in 97.8% of children and improved renal function in 2.2% of them, while no reported declined renal function (Table 3).  Tubed PCNL was significantly related to the middle pole approach, while tubeless PCNL was significantly related to the upper pole approach (p=0.002).
The access, anomalies, and anesthesia implemented were not significantly different concerning PCNL types (Table 5). Although no significant difference in clearance outcome regarding PCNL types (p=0.3), 3 children had no stone-free after post-tubed PCNL, while only one child had no stone-free following tubeless PCNL. The sepsis was not significantly different concerning PCNL types (p=0.3), however, one child had sepsis after tubeless PCNL. The renal status outcome was not significantly different regarding PCNL types (p=1.0) ( Table 6). Discussion. Until now, many surgeons preferred the classical PCNL using a nephrostomy tube in the management of pediatric kidney stones although it is associated with discomfort, pain, and longer hospitalization duration. To overcome these complications, new techniques were developed like mini-PCNL and tubeless PCNL [33,34].
The present study showed a stone-free rate of (95.6%) for children with kidney stones treated by both techniques of PCNL. This stone-free rate is better than the results of Ebeid et al, [35] study in Egypt and Pelit et al, [36] study in Turkey which reported stone-free rates of (86.3% and 84.7%, respectively) after PCNL for children with nephrolithiasis. This higher stone-free rate of both PCNL techniques in our center is attributed to the advanced instruments used and highly ex-perienced surgeons with adherent follow-up of patients. Our study also revealed no injuries with only one child with postoperative sepsis. This finding is close to the results of the Kagalkar et al, [37] study in India. In our study, no child had a declined renal status following PCNL, while 97.8% of children had stable renal status and 2.2% of them had improved renal status. Similarly, Lu et al, [38] studies in China reported higher efficacy with renal function stability following PCNL in children with urolithiasis.
The current study showed no significant difference in stone-free rate between tubed and tubeless techniques of PCNL of children with kidney stones (p=0.3). This finding coincides with the results of Iqbal et al, [26] [41] retrospective study in India and Lee et al, [42] systematic review study in South Korea which stated that renal status outcome of tubed and tubeless PCNL was similar.
The general characteristics of children in the current study were not significantly different between tubed and tubeless PCNL (p>0.05). This finding is consistent with the results of many previous pieces of literature [26,27,43]. In the same manner, surgical characteristics like access, anomalies, and anesthesia of children were not significant between tubed and tubeless PCNL (p>0.05). This finding is similar to the results of the Xun et al, [44] meta-analysis study in China. The only sig-nificant difference in the present study between tubed and tubeless PCNL was in the approach of surgery (p=0.002), as tubed PCNL was significantly related to the middle pole approach, while tubeless PCNL was significantly related to the upper pole approach. This finding coincides with the results of the aal-Toma study in Iraq [32]. It was shown that the upper pole approach of PCNL is effective in removing stones with lower postoperative complication rates [45].
Conclusion. This study concluded that percutaneous nephrolithotomy in both types (tubed and tubeless) is a safe and effective surgical option in the management of children with kidney stones. The tubeless technique of percutaneous nephrolithotomy has the same effectiveness and safety as the tubeless technique. The current study recommended that Urologists adopt the option of a tubeless technique of percutaneous nephrolithotomy in the management of pediatric nephrolithiasis to avoid complications of the tubed technique. Further national literature on the effectiveness and safety of tubeless percutaneous nephrolithotomy in children should be supported.
Conflicts of interest. The authors declare no competing interest.
Acknowledgment. Gratitude and thanks to the staff of Rzgary Hospital.
Funding. Non. Authors' contribution. All the authors equally contributed to conceptualization, data curation, formal analysis, funding acquisition, investigation, methodology, project administration, resources, software, supervision, validation, visualization, writing -original draft preparation, writing -review & editing.