胎儿膀胱在泌尿系统梗阻的磁共振成像中的生物特征和形态特征：胎儿膀胱镜检查的新视角。

Department of Pediatric Surgery and Urology, Necker-Enfants Malades Hospital, APHP, Paris, France.

EA 7328-PACT, Paris Descartes University, Sorbonne Paris Cité, Imagine Institue, Paris, France.

Ultrasound Obstet Gynecol. 2020 Jul;56(1):86-95. doi: 10.1002/uog.20297.

OBJECTIVES

Incompatibility between currently available fetoscopes and the anatomical constraints of the distended fetal bladder, with the resulting curvature around the bladder neck, account for most technical difficulties during fetal cystoscopy in lower urinary tract obstruction (LUTO). The aim of this anatomical study was to assess by magnetic resonance imaging (MRI) the variation in three bladder angles (bladder-neck angle (BNA), vesicourethral angle (VUA) and angle between bladder dome and posterior urethra (DUA)), according to gestational age (GA), bladder volume and the presence of LUTO.

METHODS

From our fetal medicine database, we retrieved for review 46 MRI examinations of male fetuses between 2015 and 2019, including 17 with LUTO, examined at a mean GA of 28.1 (range, 17.3-35.0) weeks and 29 age-matched controls, examined at 29.9 (range, 21.9-35.0) weeks. We measured bladder volume, bladder-wall thickness and the three bladder angles, and used the Mann-Whitney U-test to compare values between groups. Variations according to GA and bladder volume were determined using analysis of variance (ANOVA). A reliability study was performed using the Bland-Altman method and Lin's correlation coefficient was calculated.

RESULTS

Both bladder volume and bladder-wall thickness were significantly greater in the LUTO group (P < 0.01). BNA was significantly larger in LUTO compared with control fetuses: the mean (range) was 127.1° (101.6-161.6°) vs 111.2° (88.5-157.3°) (P < 0.01). DUA averaged 117° and showed no difference between the groups (P = 0.92). No statistical comparison was performed on VUA since this was not measurable in most control fetuses. ANOVA showed no variation of any angle with bladder volume in both LUTO fetuses and control fetuses. BNA in LUTO fetuses was the only angle to vary with GA, being larger after, compared with at or before, 25 weeks (P = 0.04). The reliability study showed an acceptable bias for both intra- and interobserver reproducibility for all three angles.

CONCLUSION

The findings that BNA is increased by approximately 15° in fetuses with LUTO and DUA averages 117° could aid in development of a customized fetal cystoscope and help to overcome the current technical challenges of fetal cystoscopy. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

目的

目前可用的胎儿镜与扩张的胎儿膀胱的解剖限制之间存在不匹配，导致膀胱颈部周围出现弯曲，这是胎儿膀胱镜检查在下尿路梗阻（LUTO）中遇到的大多数技术难题的主要原因。本解剖研究的目的是通过磁共振成像（MRI）评估三个膀胱角度（膀胱颈部角度（BNA）、膀胱尿道角（VUA）和膀胱穹窿与后尿道之间的角度（DUA））随胎龄（GA）、膀胱容量和 LUTO 的变化。

方法

从我们的胎儿医学数据库中，我们回顾性地检索了 2015 年至 2019 年间 46 例男性胎儿的 MRI 检查结果，包括 17 例 LUTO 胎儿，平均 GA 为 28.1 周（范围为 17.3-35.0 周）和 29 例年龄匹配的对照组胎儿，平均 GA 为 29.9 周（范围为 21.9-35.0 周）。我们测量了膀胱容量、膀胱壁厚度和三个膀胱角度，并使用 Mann-Whitney U 检验比较组间值。使用方差分析（ANOVA）确定随 GA 和膀胱容量的变化。使用 Bland-Altman 方法进行可靠性研究，并计算 Lin 的相关系数。

结果

LUTO 组的膀胱容量和膀胱壁厚度均显著大于对照组（P<0.01）。与对照组胎儿相比，LUTO 组的 BNA 明显更大：平均值（范围）为 127.1°（101.6-161.6°）vs 111.2°（88.5-157.3°）（P<0.01）。DUA 平均为 117°，两组间无差异（P=0.92）。由于在大多数对照组胎儿中无法测量 VUA，因此未对其进行统计学比较。ANOVA 显示，LUTO 胎儿和对照组胎儿的任何角度均不受膀胱容量变化的影响。BNA 是唯一随 GA 变化的角度，25 周后（即 25 周后）大于 25 周前或 25 周时（P=0.04）。可靠性研究表明，所有三个角度的观察者内和观察者间的可重复性均具有可接受的偏倚。