Objective To compare the effectiveness and safety of ultramini percutaneous nephrolithotomy (UMP) and retrograde intrarenal surgery (RIRS) in treatment of moderate-sized (about 1-2 cm) renal lower caliceal calculi.Methods From March 2015 to December 2016,patients in our hospital scheduled for surgery due to renal lower caliceal calculi with the greatest diameter of 10-22 mm were prospectively analyzed.Patients were randomized into two groups according to the random number table.Group UMP's operational channel was only F14 and the nephroscope's diameter was 1 mm.200 μm holmium laser lithotripsy was used to break the stones which was rushed out by eddy cuurent.In Group RIRS,all patients needed placing a F6 double J stent preoperatively for two weeks.A flexible ureteroscope sheath required imbedding intraoperatively.The stones were smashed by 200 μm holmium laser lithotripsy through the WOLF flexible ureteroscope.The intraoperative and postoperative datas including stone-free status and the complications were compared.Results 100 patients were enrolled in the study 50 patients in Group UMP,28 were male and 22 were female,mean age was 43.4 ± 7.9 years old.Mean stone size was 14.5 ±3.0 mm(range 10-22 mm).Among them,18 cases were complicated with mild and moderate hydronephrosis.The other 50 cases were allocated to Group RIRS,including 31 males and 19 females.Their mean age was 44.5 ± 8.3 years old and mean stone size was 13.7 ± 3.1 mm (range 10-21 mm).Among them,16 cases were complicated with mild and moderate hydronephrosis.No statistically significant difference were seen between the two groups (P ＞ 0.05).After three months' follow-up,one-time stone free rate(SFR) of UMP group was 94.0％ (47/50),which was significantly more superior than the 72.0％ (36/50) of the RIRS group(P ＜ 0.05).The intraoperative decrease in hemoglobin were (7.8 ± 3.3) g/L vs.(3.1 ± 3.4) g/L,and operating time(26.5 ± 6.1) min vs.(43.3 ± 6.3) min.Significant differences were also seen between the two groups(P ＜0.05).There was more blood loss and less operating time in the group of UMP.The hospital stay,delayed hemorrhage and postoperative fever between the UMP and RIRS groups were (4.3±1.3)d vs.(3.24 ± 1.21)d,8.0％ (4/50)vs.0(0/50),16.0％ (8/50)vs.12.0％ (6/50) respectively.No significant differences were seen (P ＞ 0.05).Conclusions Both UMP and RIRS procedures are effective and safe in the treatment of moderate-sized renal lower caliceal calculi.Compared with RIRS,UMP may be more effective and has less operating time,however wtih more intraoperative blood loss.

Objective:To investigate the impact of age and gender on kinetic visual acuity (KVA) and static visual acuity (SVA) in school children accepting physical activities. Methods:From May, 2018 to September, 2019, 1465 school children from various schools of Suzhou City were measured SVA and KVA with standard logarithmic visual chart and KVA detector. Results:KVA increased with age as six to nine years old, and decreased as eleven to 14. KVA was better in boys than in girls (t = 5.147, P < 0.001). SVA decreased with age as six to eight years old, fluctuated as eight to eleven, and decreased as eleven to 14, especially for girls. SVA was also better in boys than in girls (t = 3.692, P < 0.001). The prevalence of myopia increased with age as six to eight years old, and increased more significantly as eleven to 14. There was a low positive correlation between age and KVA (r = 0.046, P < 0.05), and a moderate negative correlation between age and SVA (r = -0.364, P < 0.05). KVA was positively correlated with SVA (r = 0.409, P < 0.05). Age, gender, KVA, right SVA and left SVA were the factors related with SVA. Conclusion:Vision is better in school boys than in girls. There is positive correlation between age and KVA. It is necessary to develop physical exercise according to age and gender to improve vision development, especially at the sensitive stage of visual function.