Piotr Flisiński

Tracheo-bronchial angles in the human fetus – an anatomical, digital, and statistical study

Background Both the advancement of visual techniques and intensive progress in perinatal medicine result in performing airway management in the fetus and neonate affected by life-threatening malformations. This study aimed to examine the 3 tracheo-bronchial angles, including the right and left bronchial angles, and the interbronchial angle, in the fetus at various gestational ages. Material/Methods Using methods of anatomical dissection, digital image analysis with an adequate program (NIS-Elements BR 3.0, Nikon), and statistics, values of the two bronchial angles and their sum as the interbronchial angle were semi-automatically measured in 73 human fetuses at the age of 14–25 weeks, derived from spontaneous abortions and stillbirths. Results No male-female differences between the parameters studied were found. The 3 fetal tracheo-bronchial angles were found to be independent of age. The right bronchial angle ranged from 11.4° to 41.8°, and averaged 26.9±7.0° for the whole analyzed sample. The values of left bronchial angle varied from 24.8° to 64.8°, with the overall mean of 46.2±8.0°. As a consequence, the interbronchial angle totalled 36.2–96.6°, and averaged 73.1±12.7°. Conclusions The tracheo-bronchial angles change independently of sex and fetal age. The left bronchial angle is wider than the right one. Values of the 3 tracheo-bronchial angles are unpredictable since their regression curves of best fit with relation to fetal age cannot be modelled. Both of the 2 bronchial angles and the interbronchial angle are of great relevance in the location of inhaled foreign bodies, and in the diagnosis cardiac diseases and mediastinal abnormalities.

The normal growth of the tracheal wall in human foetuses.

Introduction Tracheal wall thickness is a substantial indicator in various pathological changes. The present study was performed to compile normative data and formulae for the tracheal wall thickness and volume at varying gestational age. Material and methods Using anatomical dissection, digital image analysis and statistics a range of the wall thickness, proximal internal-to-external cross-sectional area ratio, and wall volume for the trachea in 73 spontaneously aborted human fetuses aged 14-25 weeks was examined. Results No significant male-female differences were found. The values of tracheal wall thickness ranged from 0.36 ±0.01 mm for the 14-week group to 1.23 ±0.17 mm for the 25-week group of gestation, according to the linear function y = –0.823 + 0.083 × age ± 0.087. The tracheal lumen rate, expressed as the proximal internal-to-external cross-sectional area ratio, decreased from 42.61 ±1.11% to 26.78 ±4.95%, according to the function y = 62.239 – 1.487 × age ±3.119. The tracheal wall volume rose from 16.28 ±4.18 mm3 in fetuses aged 14 weeks to 269.22 ±29.26 mm3 in fetuses aged 25 weeks, according to the quintic function y = 0.000052 × age4.894. Conclusions The tracheal wall parameters show no sexual dimorphism. The tracheal wall grows linearly in its length, and according to a quintic function in its volume. A relative decrease in the tracheal lumen at the expense of an increase in both the wall thickness and wall volume of the trachea is found during gestation.

Quantitative anatomy of the growing clavicle in the human fetus: CT, digital image analysis, and statistical study

PurposesKnowledge of dimensions of fetal long bones is useful in both the assessment of fetal growth and early detection of inherited defects. Measurements of the fetal clavicle may facilitate detection of numerous defects, e.g., cleidocranial dysplasia, Holt–Oram syndrome, Goltz syndrome, and Melnick–Needles syndrome.MethodsUsing the methods of CT, digital image analysis, and statistics, the size of the growing clavicle in 42 spontaneously aborted human fetuses (21 males and 21 females) at ages of 18–30 weeks was studied.ResultsWithout any male–female and right–left significant differences, the best fit growth models for the growing clavicle with relation to age in weeks were as follows: y = −54.439 + 24.673 × ln(age) ± 0.237 (R2 = 0.86) for length, y = −12.042 + 4.906 × ln(age) ± 0.362 (R2 = 0.82) for width of acromial end, y = −4.210 + 2.028 × ln(age) ± 0.177 (R2 = 0.77) for width of central part, y = −4.687 + 2.364 × ln(age) ± 0.242 (R2 = 0.70) for width of sternal end, y = −51.078 + 4.174 × ln(age) ± 6.943 (R2 = 0.82) for cross-sectional area, and y = −766.948 + 281.774 × ln(age) ± 19.610 (R2 = 0.84) for volume.ConclusionsWith no sex and laterality differences, the clavicle grows logarithmically with respect to its length, width, and volume, and linearly with respect to its projection surface area. The obtained morphometric data of the growing clavicle are considered normative for their respective weeks of gestation and may be of relevance in the diagnosis of congenital defects.

The normal growth of cross-sectional areas of the aorto-iliac segment in human fetuses – an anatomical, digital, and statistical study

Background The intraluminal size of the aorto-iliac segment is relevant in both the clinical and echographic settings. The aim of this study was to compile both the absolute and relative age-specific reference intervals for cross-sectional areas (CSAs) of the aorto-iliac segment. Material/Methods Using the methods of anatomical dissection, digital-image analysis (Leica QWin Pro 16) and statistical analysis (Student’s t test, one-way ANOVA, post-hoc RIR Tukey test, linear regression), the growth in CSA (in mm2) of the abdominal aorta, the common, external, and internal iliac arteries in 124 (60 males, 64 females) spontaneously aborted human fetuses aged 15–34 weeks was examined. Results No significant sex differences were found. In the age range of 4–9 months, the distal CSA of the abdominal aorta ranged from 0.87±0.34 to 19.18±3.36 mm2. The CSA of the common iliac artery varied from 0.37±0.22 to 4.30±1.54 mm2 on the right, and from 0.36±0.16 to 3.80±1.44 mm2 on the left. The sum of the CSAs of the right and left common iliac arteries grew proportionately to the distal CSA of the abdominal aorta; the latter being significantly larger than the former. On both sides, however, the CSA of the internal iliac artery was approximately twice that of the external iliac artery. Between the ages of 4 and 9 months, the CSA of the external iliac artery ranged from 0.10±0.06 to 1.32±0.52 mm2 on the right, and from 0.08±0.03 to 1.19±0.42 mm2 on the left. The CSA of the internal iliac artery increased from 0.23±0.14 to 2.59±1.22 mm2 on the right, and from 0.21±0.14 to 2.27±1.11 mm2 on the left. Bilaterally, the sum of the CSAs of the internal and external iliac arteries was significantly smaller than the CSA of the common iliac artery. The relative CSA of each artery decreased until the age of 6 months, after which their values were gradually increasing until the age of 9 months. Conclusions The aorto-iliac segment does not reveal sex differences in its cross-sectional area. The cross-sectional area of the internal iliac artery is approximately twice the size of the external iliac artery. The aorto-iliac segment observed proximally to distally reduces its cross-sectional area, thereby resulting in an increase in blood velocity.