Comparison the outcomes between prone and supine ultramini percutaneous nephrolithotomy in pediatric patients

Objective: Comparison between prone and supine position percutaneous ultra-mini nephrolithotomy (UMP) in pediatric patients. Patients and Methods: Dataof pediatric patients under the age of 15 were analyzed retrospectively who underwent ultra-mini PNL (UMP) between March 2012 and March 2016 in Dicle University Medical Faculty Urology Clinic. The demographic characteristics, perioperative and postoperative data of the patients were recorded .Patients stratified into two groups according to position during operation in terms of prone UMP (Group 1) and supine UMP (Group 2). Age, gender, stone size, stone location, degree of hydronephrosis, the access technique, operation time, fluoroscopy time, stone opacity, stone-free status, drainage method, the amount of bleeding and complications degrees were compared between each group. Results: There were 80 patients in Group 1 and 38 patients (40 renal units) in Group 2. Gender distribution was 55 males, 25 females in Group 1 and 20 males, 18 females in Group 2. Mean age of the patients was 3,9 ± 3,4 years in pron UMP group and 5,6 ± 4,6 years in supin UMP group. The mean stone size was 19,6 ± 7,5 and 20,7 ± 6,8 mm, respectively.Mean operation time was 58,1 ± 15,6 and 49,5 ± 18,9 minutes in Group 1 and Group 2, respectively. Supine UMP group mean operation time was shorter and this difference was statistically significant (p = 0,002). Mean fluoroscopy time was 2,3 ± 1,2 minutes in Group 1 and 1,1 ± 0,5 minutes in Group 2, besides statistically significant difference was detected (p = 0,000). Mean duration of hospitalization was 3,7 ± 2,0 and 2,3 ± 0,7 days in Group 1 and Group 2, respectively. Mean hemoglobin decrease was 0,9 ± 0,7 g / dl and 0,9 ± 0,6 g / dl in Group 1 and Group 2 and statistically significant difference was not observed between groups (p = 0.748). At the first month control stone-free status was achieved 65(81,3%) patients in Group 1, 34 (85,0%) patients in Group 2. Additional interventions performed 6 patients in Group 1 and 3 renal units in Group 2. The stone-free rate after additional intervention was 71 (88,8%) and 37 (92,5%) in Group 1 and Group 2 ,respectively. A statistically significant difference was not observed between groups before and after additional interventions. Complications were observed in 32 (26,6%) patients. The distribution of complications according to the modified Clavien scale were 11 (9,2%) patients Grade 1, 12 (10,0%) patients Grade 2, 6 (5,0%) patients Grade 3a and 3 (2,5%) patients Grade 3b. A statistically significant difference in terms of complication rate and degree between prone and supine UMP groups was not observed.(p = 0.436) Conclusion : Ultra-mini percutaneous nephrolithotomy in the supine position is a similarly safe and effective method like prone position PNL, for the treatment of stone disease in the pediatric age group. Keywords:Supine, Ultra Mini-PNL, Pediatric, Nephrolithiasis