Treatment alternatives for urinary system stone disease in preschool aged children: results of 616 cases.
INTRODUCTION
The treatment of stone disease is mostly similar in those adult and children. The standard treatment procedures are as follows: extracorporeal shock wave lithotripsy (ESWL), ureterorenoscopy (URS), percutaneous nephrolithotomy (PCNL), and laparoscopic surgery in selected cases. Open surgery (OS) is another option particularly in such cases with anatomic abnormalities of urinary tract.


OBJECTIVE
The present study aims to provide comparative results of stone removal procedures in preschool aged patients who were diagnosed with urinary system stone disease.


STUDY DESIGN
The retrospective data of 616 pediatric preschool patients consulted with urinary system stone disease between January 2009 and July 2013 were evaluated. All patients were evaluated with Kidney-Ureter-Bladder (KUB) Xray and abdomino-pelvic ultrasound. Intravenous pyelography, unenhanced computed tomography (CT), and renal scintigraphy were performed when needed. Patients were categorized according to the procedures as: Group ESWL, Group URS, Group PNL, Group micro-PNL and Group OS. Following the procedures, opaque residual stones were evaluated with KUB Xray, and non-opaque residual stones were evaluated with unenhanced CT.


RESULTS
In groups (ESWL, URS, PNL, micro-PNL, OS), the stone-free rate was 68%, 66%, 85%, 100% and 94 %, respectively. The stone analysis were observed as, calcium oxalate in 377 patients (61.2%), uric acid in 106 patients (17.2%), infection stone in 73 patients (11.8 %), and cysteine in 60 patients (9.7%). There was no significant difference in stone analysis between the groups (p > 0.05) (Table).


DISCUSSION
Minimally invasive procedures are frequently preferred in the pediatric age urinary system stone disease. These procedures are ESWL, PCNL, and ureteroscopy [10,11]. Open surgery is reserved only for rare cases [12]. Similarly the current literature, 18 (2.9%) patients had anatomical anomaly and had high complex stone burden were treated with open surgery in our study. ESWL is a preferred treatment method for pediatric urolithiasis patients with a stone size <20 mm, and the rate of stone-free after ESWL ranges between 57 and 92% [13]. In a study showed the effect of stone size on the success rate in ESWL, the success rate was 91% for stones <10 mm, and 75% for stones >10 mm [15]. In the present study, stone-free rate was noted as 68% on 15 mm or lower stone size. PNL is commonly used to treat stone disease in preschool children [18-20]. In the beginning, urologists hesitated to use instruments suited for adults in case of pediatric kidneys. While some authors accept a cut-off value of 24 F for tract dilatation in the pediatric age, Desai et al. recommended a threshold value <22 F [19,21]. In our study, we used adult PNL instruments in the early period, whereas mini-PERC was performed in the later years. The success rate in PNL group was found as 85%. In recent years, the micro-PNL procedure has been developed to reduce/prevent the complications of standard PNL. In our study, the success rate was calculated as 100% with micro-PNL. This study has certain limitations. The major limitation of our study is its retrospective nature. In addition, sample size of micro-PNL group is fewer than other groups.


CONCLUSION
The goal of kidney stone treatment is to achieve minimal kidney damage and a high success rate. Thus, the procedures are important in the pediatric age group where life expectancy is high, and particularly in the preschool age group.