Huang Yangyue, Liu Pei, Sun Ning, Zhang Weiping, Song Hongcheng
Department of Pediatric Urology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, 100045, China.
Department of Pediatric Urology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, 100045, China.
J Pediatr Urol. 2020 Jun;16(3):356.e1-356.e6. doi: 10.1016/j.jpurol.2020.02.006. Epub 2020 Feb 17.
Contralateral testicular size was recommended as an effective measurement in prediction of monorchidism in some previous studies but a few argued it as invalid. Further investigation was demanded.
To investigate the effectiveness of contralateral testicular size in prediction of monorchidism in patients with unilateral non-palpable undescended testes (NPT) aged between 9 and 48 months.
Total of 707 patients aged between 9 and 48 months and diagnosed with unilateral undescended testes (UDT) between January 2016 and December 2018 at the study department were enrolled. In accordance with physical examinations and surgical findings, patients were divided into three groups: palpable UDT (group A, n = 609), non-palpable but viable testes (group B, n = 57) and monorchidism (group C, n = 41). Contralateral testicular length and volume were evaluated with ultrasonography. Comparison of contralateral testicular size between three groups and calculation of optimal cut-off value and diagnostic performance of it among NPT were performed.
The length and volume of contralateral testes of group C were larger than of group A (P < 0.01) and group B (P < 0.01), whereas these differences between groups were small. Among patients with NPT, a receiver operating characteristic curve was used to determine the optimal cut-off value. It revealed that both a testicular length of 17.5 mm and a volume of 1.05 ml provided the highest Youden's index for prediction of monorchidism. The sensitivity and specificity for testicular length were 34.1% and 94.7%, and volume were 34.1% and 93%, respectively. The predictive accuracy for testicular length and volume were 69.4% and 65.7%, respectively. Even though the negative predictive value was merely 66.6% (54/81) and 66.2% (53/80), the positive predictive value (PPV) reaches to 82.3% (14/17) and 77.7% (14/18) for testicular length and volume.
Several factors including choosing of measurement tools, age range, ethnicity, and selection bias of cohorts may be accounted for the huge differences among cut-off values and predictive accuracy. The diagnostic performance of contralateral testicular size in prediction of monorchidism in patients with NPT was poor. But the PPV was relatively promising. Contralateral testicular hypertrophy can provide information for surgical planning.
The overall diagnostic performance of contralateral testicular size in prediction of monorchidism in poatients with UDT aged between 9 and 48 months was poor. But the efficiency of cut-off value predicting absence of viable testes was relatively higher. This value should be objectively applied but only as a reference which would not be a complete replacement of laparoscopy exploration.
在之前的一些研究中，对侧睾丸大小被推荐作为预测单睾症的有效指标，但也有少数人认为其无效。因此需要进一步研究。
探讨对侧睾丸大小对9至48个月单侧不可触及隐睾（NPT）患者单睾症的预测效果。
选取2016年1月至2018年12月在本研究科室诊断为单侧隐睾（UDT）的707例9至48个月的患者。根据体格检查和手术结果，将患者分为三组：可触及的UDT（A组，n = 609）、不可触及但存活的睾丸（B组，n = 57）和单睾症（C组，n = 41）。采用超声评估对侧睾丸的长度和体积。比较三组间对侧睾丸大小，计算最佳截断值及其在NPT中的诊断性能。
C组对侧睾丸的长度和体积大于A组（P < 0.01）和B组（P < 0.01），但组间差异较小。在NPT患者中，采用受试者工作特征曲线确定最佳截断值。结果显示，睾丸长度17.5 mm和体积1.05 ml时预测单睾症的约登指数最高。睾丸长度的敏感性和特异性分别为34.1%和94.7%，体积的敏感性和特异性分别为34.1%和93%。睾丸长度和体积的预测准确率分别为69.4%和65.7%。尽管阴性预测值仅为66.6%（54/81）和66.2%（53/80），但睾丸长度和体积的阳性预测值分别达到82.3%（14/17）和77.7%（14/18）。
包括测量工具的选择、年龄范围、种族和队列选择偏倚等多种因素可能导致截断值和预测准确率存在巨大差异。对侧睾丸大小对NPT患者单睾症的诊断性能较差。但阳性预测值相对有前景。对侧睾丸肥大可为手术规划提供信息。
对侧睾丸大小对9至48个月UDT患者单睾症的总体诊断性能较差。但截断值预测无存活睾丸的效率相对较高。该值应客观应用，但仅作为参考，不能完全替代腹腔镜探查。
