产前超声经颅底横断面评估胎儿鼓室环

Evaluation of Fetal Tympanic Rings via Prenatal Ultrasound Through the Skull Base

目的产前超声经颅底横断面观察12~31+6周胎儿鼓室环的发育情况,预测胎儿外耳道的发育。资料与方法回顾性纳入2020年7月-2021年9月在安徽省妇幼保健院进行产前超声检查并经颅底横断面测量鼓室环前后径的238例胎儿,于出生或引产后确认其耳廓及外耳道的发育情况。分析正常胎儿与耳廓畸形及外耳道闭锁或狭窄胎儿鼓室环前后径、外耳廓长径的差异,并分析正常胎儿鼓室环前后径与孕周、外耳廓长的相关性。结果238例胎儿中,10例单侧小耳畸形合并外耳道闭锁,1例右侧小耳畸形、左侧耳廓形态异常合并双侧外耳道闭锁,1例左侧小耳畸形合并外耳道狭窄。12例外耳道闭锁侧产前超声鼓室环均未显示,1例外耳道狭窄侧鼓室环明显小于正常侧。正常胎儿不同孕周左、右侧鼓室环前后径、外耳廓长径差异均无统计学意义(t=-0.541~0.153、-0.696~1.136,P均>0.05)。正常胎儿与异常胎儿患侧鼓室环前后径、外耳廓长径差异均有统计学意义(P均<0.001)。异常胎儿健侧与患侧鼓室环前后径、外耳廓长径差异均有统计学意义(P均<0.001)。正常胎儿与异常胎儿健侧鼓室环前后径、外耳廓长径差异均无统计学意义(P均>0.05)。正常胎儿鼓室环前后径与孕周、外耳廓长径的相关性较好(r2=0.775、0.745,P均<0.001)。结论胎儿鼓室环是外中耳发育异常的可靠指标,其前后径随孕周及外耳廓长径增加而增长,中孕期超声评估鼓室环是可行的,评估鼓室环的发育可以帮助临床解决产前诊断外耳道闭锁、狭窄的难题,有助于产前及产后进行多学科咨询。

Purpose The development of the fetal tympanic ring at 12 to 31+6 weeks was observed via prenatal ultrasound through the skull base cross section to predict the development of the fetal external auditory canal.Materials and Methods A total of 238 fetuses who underwent prenatal ultrasound examination in Anhui Province Maternity and Child Health Hospital from July 2020 to September 2021 and measured the anteroposterior diameter of the tympanic ring through the cross section of the skull base were retrospectively included.The development of auricle and external auditory canal was confirmed after birth or induction of labor.The differences between the anteroposterior diameter of the tympanic ring and the long diameter of the external auricle in normal fetuses and auricle malformations,as well as in fetuses with atresia or stenosis of the external auditory canal were analyzed,and the correlation between the anteroposterior diameter of the tympanic ring and the gestational age and the length of the external auricle in normal fetuses was further analyzed.Results Among the 238 fetuses,10 were unilateral microtia with atresia,1 was right microtia with abnormal shape of left auricle and bilateral atresia of external auditory meatus,1 case was left microtia with external auditory meatus stenosis.The tympanic rings on the 12 sides of the atresia of the external auditory meatus were not shown via prenatal ultrasound,and the tympanic rings on the narrow side of the external auditory meatus in 1 case were significantly smaller than that on the normal side.There was no significant difference in the anteroposterior diameter of tympanic ring and the length of auricle between the left and right sides of normal fetus(t=-0.541-0.153,-0.696-1.136,all P>0.05).The anteroposterior diameter of tympanic ring and the length of auricle were significantly different between normal and abnormal fetuses(all P<0.001).The anteroposterior diameter of tympanic ring and the length of auricle were significantly different between the normal side and the affected side(both P<0.001).There was no significant difference in the anteroposterior diameter of the contralateral tympanic ring and the length of the external ear between normal and abnormal fetuses(both P>0.05).Linear regression analysis showed that there was a good correlation between the anteroposterior diameter of the tympanic ring and the gestational age and the length of the outer ear(r2=0.775 and 0.745,both P<0.001).Conclusion Fetal tympanic ring is a reliable indicator of abnormal development of the external and middle ear.Its anteroposterior diameter increases with gestational age and external auricle.Ultrasound assessment of the tympanic ring in the second trimester is feasible,evaluation of the development of the tympanic ring can help us solve the problem of prenatal diagnosis of atresia and stenosis of the external auditory canal,and facilitate multidisciplinary consultation before and after delivery.