Hosokawa Takahiro, Hosokawa Mayumi, Tanami Yutaka, Takahashi Hiroaki, Hattori Shinya, Sato Yumiko, Tanaka Yujiro, Kawashima Hiroshi, Oguma Eiji, Yamada Yoshitake
Ultrasound Q. 2018 Mar;34(1):18-22. doi: 10.1097/RUQ.0000000000000329.
This study was to evaluate the correlation between birth weight and the distance between distal rectal pouch and perineum (P-P distance) and to determine a cutoff value for P-P distance to diagnose low-type imperforate anus in neonates with low-birth weight (LBW).We included 15 neonates with LBW (mean weight, 2012 ± 470 g; range, 906-2452 g) and imperforate anus (surgically confirmed: 11 low type and 3/1 intermediate/high type), who underwent ultrasonography on the day after birth. Type of imperforate anus was defined based on the International Classification of Anorectal Anomalies. The P-P distances on ultrasonograms were measured. Pearson correlation coefficient test and receiver operating characteristic curve were used for statistical analyses.Among all 15 neonates, nonsignificant correlation was observed between the birth weight and P-P distance (r = 0.36; P = 0.18). Mean P-P distance was 9.0 ± 6.6 mm (range, 1.0-24.0 mm) in all neonates, 5.7 ± 2.8 mm (range, 1.0-11.0 mm) in the 11 neonates with low-type imperforate anus, and 18.3 ± 9.1 mm (range, 14.0-24.0 mm) in the 4 neonates with intermediate-/high-type imperforate anus. Using cutoff P-P distance of 12.5 mm, sensitivity and specificity for diagnosis of low-type imperforate anus were 100% (11/11) and 100% (4/4), respectively.In conclusion, nonsignificant correlation was observed between P-P distance and birth weight, and cutoff P-P distance to diagnose low-type imperforate anus was 12.5 mm. Despite the very small sample size in our study, and only 4 neonates with intermediate-/high-type imperforate anus, these findings are important because surgical management whether transperineal anoplasty or diverting colostomy is decided based on the type of imperforate anus, and P-P distance to diagnose the type of imperforate anus was feasible even in neonates with LBW.
本研究旨在评估出生体重与直肠远端盲袋与会阴之间的距离（P-P距离）的相关性，并确定低出生体重（LBW）新生儿中诊断低位型肛门闭锁的P-P距离临界值。我们纳入了15例LBW新生儿（平均体重2012±470g；范围906 - 2452g）且患有肛门闭锁（手术确诊：11例低位型，3/1例中间型/高位型），这些新生儿在出生后第二天接受了超声检查。肛门闭锁类型根据国际肛门直肠畸形分类进行定义。测量超声图像上的P-P距离。采用Pearson相关系数检验和受试者操作特征曲线进行统计分析。在所有15例新生儿中，出生体重与P-P距离之间未观察到显著相关性（r = 0.36；P = 0.18）。所有新生儿的平均P-P距离为9.0±6.6mm（范围1.0 - 24.0mm），11例低位型肛门闭锁新生儿的平均P-P距离为5.7±2.8mm（范围1.0 - 11.0mm），4例中间型/高位型肛门闭锁新生儿的平均P-P距离为18.3±9.1mm（范围14.0 - 24.0mm）。使用12.5mm的P-P距离临界值，诊断低位型肛门闭锁的敏感性和特异性分别为100%（11/11）和100%（4/4）。总之，P-P距离与出生体重之间未观察到显著相关性，诊断低位型肛门闭锁的P-P距离临界值为12.5mm。尽管我们研究中的样本量非常小，且仅有4例中间型/高位型肛门闭锁新生儿，但这些发现很重要，因为手术管理无论是经会阴肛门成形术还是转流性结肠造口术都是根据肛门闭锁类型决定的，并且即使在LBW新生儿中，通过P-P距离诊断肛门闭锁类型也是可行的。
