汉族儿童上尿路结石腔内手术学习曲线研究

Learning curve in the training of endourological surgery for upper urinary tract calculi in children

目的探讨汉族儿童上尿路结石腔内手术学习曲线,为具备一定泌尿系结石腔内手术经验的临床外科医师开展儿童泌尿系结石腔内手术提供循证依据。方法自首都医科大学附属北京友谊医院2014年6月至2019年4月前瞻性构建的汉族儿童泌尿系结石数据库中选取348例汉族患儿纳入此项研究。其中,男250例,女98例;中位年龄为3岁;中位体重指数为17.1 kg/m2。根据患儿结石位置、大小、身体基础条件等选择行经皮肾碎石术(percutaneous nephrolithotripsy,PCNL)术、输尿管镜碎石术(ureterscopic lithotripsy,URL)或PCNL和URL联合手术。并根据手术次序,将行PCNL和URL的患儿各分为三个亚组。统计分析患儿的基线资料、术中数据、结石清空率(stone free rate,SFR)及术后并发症发生率(complication rate,CR)情况,采用SPSS 22.0进行统计分析,在R3.5.1中进行非参数LOWESS回归建模,并绘制学习曲线来体现术者手术经验对腔内手术安全性及有效性的影响。结果348例患儿共行腔内手术375次,手术侧别共416侧,中位手术时间为30 min,中位术中灌注量为500 ml,中位结石负荷为1.77 cm2。结石的整体清空率为88.0%(330/375),并发症发生率为25.0%(87/348)。其中发热62,血尿56例,石街2例。URL第1、2、3组中位结石负荷分别为0.5、0.8和1.8 cm2,中位结石质量分别为375、824和1321 cm2×Hu,SFR分别为83.6%(92/110)、85.5%(94/110)和86.4%(95/110),均呈逐渐递增趋势,且组间比较差异有统计学意义(P均<0.05);中位术中灌注量分别为500、400和200 ml,术后发热发生率分别为18.2%(20/110)、10.0%(11/110)、8.2%(9/110),均呈逐渐递减趋势,组间差异有统计学意义(P均<0.05);术后血尿发生率分别为2.7%(3/110)、9.1%(10/110)、11.8%(13/110),呈逐渐递增趋势,组间比较差异有统计学意义(P<0.05)。PCNL第1、2、3组结石质量分别为3163、5141和5399 cm2×Hu,中位术中灌注量分别为1000、1300和1500 ml,SFR分别为41.4%(12/29)、65.5%(19/29)和78.6%(22/28),均呈逐渐递增趋势,组间比较差异有统计学意义(P均<0.05);术后血尿发生率分别为27.6%(8/29)、31.0%(9/29)、46.4%(13/28),呈逐渐递增趋势,组间比较差异有统计学意义(P均<0.05);术后发热发生率分别为34.5%(10/29)、27.6%(8/29)和14.3%(4/28),呈逐渐递减趋势,组间差异亦有统计学意义(P<0.05)。绘制学习曲线可见,随着腔内手术例数的积累,手术时长明显缩短,结石清空率逐渐增加,但手术时间及清石率也呈现进入学习曲线的平台。随着术者对结石质量较大患儿的纳入及患儿BMI的影响,术后并发症发生率在一定的学习曲线的平台期之后出现升高。结论随着手术经验的积累,可显著提高结石清空率,缩短手术时间。

Objective To report the learning curve in the training of endourological surgery for upper urinary tract calculi in children and to provide surgical rationales of upper urinary tract calculi to surgeons with some experience in endourological surgery of urolithiasis.Methods From June 2014 to April 2019,a prospectively managed database containing 348 Han children with upper urinary tract calculi undergoing endourological surgery was analyzed.Percutaneous nephrolithotripsy(PCNL),ureteroscopic lithotripsy(URL)or PCNL plus URL were performed according to the location/size of stones and physical status.According to the sequence of operations,PCNL and URL were classified into three subgroups.Patient demographics,intraoperative data,stone free rate(SFR)and complication rate(CR)were collected.And SPSS 22.0 was utilized for statistical analysis and nonparametric LOWESS regression model constructed with R3.5.1.Learning curves were plotted for estimating the effect of surgeon's experience on surgical outcomes.Results The final analysis included 416 sides of 348 children in 375 operations.There were 250 boys and 98 girls.The median age was 3 years and median BMI(body mass index)17.1 kg/m2.Median operative duration was 30 min,median intraoperative perfusion 500 ml and median stone burden 1.77 cm2.The overall SFR was 88.0%(330/375)and CR 25.0%(87/348).Fever occurred in 62 children and hematuria occurred in 56(modified Clavien gradeⅠ-Ⅱ).Steinstrasse was found in 2 children(modified Clavien gradeⅡ).The median stone burden in the first,second and third groups of URL was 0.5,0.8 and 1.8 cm2 and the median stone mass 375,824 and 1,321 cm2;SFR 83.6%(92/110),85.5%(94/110)and 86.4%(95/110)showed a gradual rising trend and the inter-group differences were statistically significant(P<0.05).Median intraoperative perfusion 500,400 and 200 ml showed a gradual declining trend.The inter-group differences were statistically significant(P<0.05).The postoperative incidence of hematuria among three groups was 2.7%(3/110),9.1%(10/110)and 11.8%(13/110)respectively,showing a gradual rising trend.The inter-group differences were statistically significant(P<0.05).The postoperative fever rates of three groups gradually declined and the inter-group differences of 18.2%(20/110),10.0%(11/110)and 8.2%(9/110)were statistically significant(P<0.05).The stone burden of PCNL group 1/2/3 were 3,163,5,141 and 5,399 cm2;median intraoperative perfusion 1,000,300 and 1,500 ml and SFR 41.4%(12/29),65.5%(19/29)and 78.6%(22/28)displayed a gradual rising trend and inter-group differences were statistically significant(P<0.05).The postoperative incidence of hematuria among three groups was 27.6%(8/29),31.0%(9/29),46.4%(13/28)respectively,showing a gradual rising trend.Inter-group differences were statistically significant(P<0.05).The postoperative fever rates of three groups showed a gradual declining trend and inter-group differences of 34.5%(10/29),27.6%(8/29)and 14.3%(4/28)were statistically significant(P<0.05).Learning curves showed that operative duration declined and SFR spiked with a larger load of cases.However,operative duration and SFR also presented a plateau.The incidence of postoperative complications increased after plateau period of a certain learning curve with the inclusion of children with high stone mass and the effect of BMI.Conclusion Richer surgical experience is associated with improvements in SFR and a reduction of operative duration.