Sahni Daisy, Batra Yatindra Kumar, Rajeev Subramanyam
Department of Anatomy Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Paediatr Anaesth. 2008 Nov;18(11):1029-34. doi: 10.1111/j.1460-9592.2008.02775.x.
The increasing opportunities to consider fetal intervention in selected cases of life-threatening malformations have necessitated airway management of fetuses with low gestational age. This study is aimed to determine the anatomical dimensions of trachea, main bronchi, subcarinal and bronchial angles and their correlation to age and crown rump length (CRL) in fetuses.
Measurements of tracheo-bronchial dimensions including the subcarinal and bronchial angles with the vertical were taken in specimens obtained from 40 fetuses, varying in CRL from 61 to 270 mm. The incidence of different shapes at the upper end of trachea was studied. The subcarinal and angles of main bronchi with the vertical were measured radiographically with 20% barium sulfate, in another group of 21 fetuses varying in CRL from 63 to 129 mm.
Forty fetuses (22 males, 18 females) were analyzed for the dimensions based on CRL (61-130 mm; 131-200 mm; 201-270 mm--CRL 1, 2, and 3 respectively). The internal transverse diameter of trachea was found to increase steadily from 1.87 +/- 0.56 to 2.67 +/- 0.7 mm (P < 0.001) and 3.68 +/- 0.39 mm (P < 0.001) with increasing CRL. Similarly the outer transverse and antero-posterior diameter of the trachea increased steadily with age. Tracheal length was found to increase significantly to 17.48 +/- 2.89 mm and 24.17 +/- 2.3 from 12.72 +/- 2.5 mm (P < 0.001). The length of paries membranaceous increased with gestational age. Although the length of bronchi increased significantly and linearly, subcarinal and bronchial angles did not show any significant changes with age. There was no sexual dimorphism in measurements in the fetuses of corresponding CRL. Oval shaped trachea was found in 60% and circular in 40% of fetuses. The measurements of subcarinal and bronchial angles performed by radiology were almost the same as those measured in trachea separated from fetuses.
The internal transverse, outer transverse and antero-posterior diameters, length of trachea and bronchi and circumference of trachea, relate in a linear fashion to CRL and age. However, subcarinal and bronchial angles remained constant.
在某些危及生命的胎儿畸形病例中，考虑进行胎儿干预的机会日益增多，这就需要对低孕周胎儿进行气道管理。本研究旨在确定胎儿气管、主支气管、隆突下及支气管角度的解剖学尺寸，以及它们与胎儿年龄和顶臀长（CRL）的相关性。
对40例顶臀长在61至270毫米之间的胎儿标本进行气管支气管尺寸测量，包括隆突下和支气管与垂直线的夹角。研究气管上端不同形状的发生率。在另一组21例顶臀长在63至129毫米之间的胎儿中，用20%硫酸钡进行X线摄影测量隆突下和主支气管与垂直线的夹角。
根据顶臀长（分别为CRL 1、2和3，即61 - 130毫米；131 - 200毫米；201 - 270毫米）对40例胎儿（22例男性，18例女性）进行尺寸分析。发现气管的内部横径随着顶臀长增加而稳步增加，从1.87±0.56毫米增至2.67±0.7毫米（P < 0.001），再增至3.68±0.39毫米（P < 0.001）。同样，气管的外部横径和前后径也随着年龄稳步增加。气管长度从12.72±2.5毫米显著增加至17.48±2.89毫米和24.17±2.3毫米（P < 0.001）。膜壁长度随孕周增加。虽然支气管长度显著且呈线性增加，但隆突下和支气管角度并未随年龄显示出任何显著变化。在相应顶臀长的胎儿测量中没有性别差异。60%的胎儿气管呈椭圆形，40%呈圆形。放射学测量的隆突下和支气管角度与从胎儿分离出的气管测量值几乎相同。
气管的内部横径、外部横径和前后径、气管和支气管长度以及气管周长与顶臀长和年龄呈线性关系。然而，隆突下和支气管角度保持恒定。
