The development of fetal pylorus during the fetal period

Ultrasonographic Imaging of the Fetal Pyloric Sphincter

OBJECTIVES

In this study, we hypothesized that the pyloric sphincter can be directly visualized by ultrasonography in the prenatal period.

METHODS

This study was designed as a cross-section. Single, healthy pregnancies between 18 and 22 weeks of gestation who applied to the Perinatology outpatient clinic for second-level ultrasonography were included in the study. In addition to the demographic characteristics of the participants, fetal pyloric mucosa, fetal pyloric sphincter length, and fetal pyloric sphincter thickness were measured by ultrasonography. Intrarater variability was calculated.

RESULTS

A total of 93 eligible patients were evaluated in the study. The mean age of the participants was 27.25 ± 6.23, and the gestational age was 21.18 ± 0.98. Pylorus imaging and measurements were possible in all fetuses that were in the optimal position. Mean pyloric sphincter length (mm) was 5.32 ± 0.93, pyloric sphincter thickness (mm) was 2.13 ± 0.44, and sphincter muscle thickness (mm) was 1.05 ± 0.24.

CONCLUSIONS

The pyloric sphincter can be easily visualized on a second-trimester ultrasound scan when the appropriate technique is used. This may make an additional contribution to the diagnosis of fetal gastrointestinal tract pathologies.

Ultrasound examination of the normal fetal duodenum

Objective

To use the fetal pylorus as a reference point to conveniently display the normal fetal duodenum by ultrasound.

Methods

This study was designed in cross-section. A total of 450 healthy singleton pregnant women at 19-39 weeks of gestation who underwent prenatal screening at our hospital from January 2019 to February 2020 were selected. They were divided into three groups according to gestational weeks: the 19-23 gestational weeks group, 29-32 gestational weeks group, and 34-39 gestational weeks group. The duodenal bulb was identified. Its movement and course were continuously and dynamically observed. The descending part of the duodenum was identified, and the duodenal course was traced.

Results

The fluid-filled in the fetal duodenum was discontinuous. The overall detection rates of the duodenum in the 19-23 gestational weeks group, 29-32 gestational weeks group, and the 34-39 gestational weeks group were 82.2%, 26.2%, and 13.8%, respectively. The detection rates of the bulbar, descending, horizontal, and ascending parts of the duodenum were 94.4%, 58.2%, 58.0%, and 52.0%, respectively. The anatomical structures of the duodenum as a whole and the pancreas were most easily recognized in the 19-23 gestational weeks group; while in the 34-39 gestational weeks group, the bulbar part had a maximum detection rate of 98.8%, and it had the longest filling time and the shortest examination time.

Conclusion

The pylorus is an ideal starting point for tracing the fetal duodenum. The overall detection rate of the fetal duodenum decreases with gestational age. The duodenal bulb is the most easily detected site.

Ultrasonographic Imaging of the Fetal Duodenal Tract

OBJECTIVES

To investigate whether fetal duodenal tract sections can be visualized in the prenatal ultrasonographic examination.

METHODS

This study was designed in cross-section. Healthy singleton pregnant women who applied to the perinatology outpatient clinic for second-level ultrasound scanning between September 2020 and February 2021 were included in the study. Demographic information of the participants was obtained and an ultrasound scan was performed. The fetal duodenal tract was evaluated in three sections, including the pylorus. The fetal duodenal tract was differentiated from adjacent organs by its anatomical location, hyperechoic nature, and presence of fluid in the lumen.

RESULTS

A total of 278 eligible participants between 18 and 22 weeks of gestation were evaluated. While the fetal pylorus was closed in 76.6% of the participants, it was open in 23.4%. Duodenum pars superior, pars descendens, and pars inferior imaging rates were 99.3%, 98.2%, and 95.7%, respectively. It was possible to distinguish these parts from neighboring organs by 99.6%, 100%, and 100%, respectively. While the first, second, and third parts of the duodenum were observed as solid in 42.0%, 58.2%, and 52.2%, respectively, 57.9%, 41.7%, and 47.7% had fluid in the lumen.

CONCLUSION

The fetal duodenal tract can be viewed with prenatal ultrasonography in pregnant women who are not in a dorsoanterior position. This may make an additional contribution to the diagnosis of duodenal obstructions, which is the most common cause of intestinal atresia in prenatal screening.

Infantile hypertrophic pyloric stenosis in patients with esophageal atresia

BACKGROUND

Patients born with esophageal atresia (EA) have a higher incidence of infantile hypertrophic pyloric stenosis (IHPS), suggestive of a relationship. A shared etiology makes sense from a developmental perspective as both affected structures are foregut derived. A genetic component has been described for both conditions as single entities and EA and IHPS are variable components in several monogenetic syndromes. We hypothesized that defects disturbing foregut morphogenesis are responsible for this combination of malformations.

METHODS

We investigated the genetic variation of 15 patients with both EA and IHPS with unaffected parents using exome sequencing and SNP array-based genotyping, and compared the results to mouse transcriptome data of the developing foregut.

RESULTS

We did not identify putatively deleterious de novo mutations or recessive variants. However, we detected rare inherited variants in EA or IHPS disease genes or in genes important in foregut morphogenesis, expressed at the proper developmental time-points. Two pathways were significantly enriched (p < 1 × 10^-5 ): proliferation and differentiation of smooth muscle cells and self-renewal of satellite cells.

CONCLUSIONS

None of our findings could fully explain the combination of abnormalities on its own, which makes complex inheritance the most plausible genetic explanation, most likely in combination with mechanical and/or environmental factors. As we did not find one defining monogenetic cause for the EA/IHPS phenotype, the impact of the corrective surgery could should be further investigated.

Pyloric atresia in the neonate

Bowel obstruction is a common cause for admission into the NICU, but pyloric atresia (PA) is a very rare cause of bowel obstruction. This article illustrates the development of the fetal gastrointestinal tract, most specifically the stomach and pylorus. Pathophysiology, typing, and treatment of PA are also explored. Presented are two cases of PA that occurred in a Level III NICU one month apart. Management of this condition is surgical in nature. Long-term prognosis is usually excellent because this defect is often isolated.

Surgical Anatomy of the Gastrointestinal Tract and Its Vasculature in the Laboratory Rat

The aim of this study was to describe and illustrate the morphology of the stomach, liver, intestine, and their vasculature to support the planning of surgical therapeutic methods in abdominal cavity. On adult Wistar rats corrosion casts were prepared from the arterial system and Duracryl Dental and PUR SP were used as a casting medium and was performed macroscopic anatomical dissection of the stomach, liver, and intestine was performed. The rat stomach was a large, semilunar shaped sac with composite lining. On the stomach was very marked fundus, which formed a blind sac (saccus cecus). The rat liver was divided into six lobes, but without gall bladder. Intestine of the rat was simple, but cecum had a shape as a stomach. The following variations were observed in the origin of the cranial mesenteric artery. On the corrosion cast specimens we noticed the presence of the anastomosis between middle colic artery (a. colica media) and left colic artery (a. colica sinistra). We investigated the second anastomosis between middle colic artery and left colic artery. The results of this study reveal that the functional anatomical relationship between the rat stomach, liver and intestine is important for the development of surgical research in human and veterinary medicine.

Morphogenesis and three-dimensional movement of the stomach during the human embryonic period

The stomach develops as the local widening of the foregut after Carnegie stage (CS) 13 that moves in a dramatic and dynamic manner during the embryonic period. Using the magnetic resonance images of 377 human embryos, we present the morphology, morphometry, and three-dimensional movement of the stomach during CS16 and CS23. The stomach morphology revealed stage-specific features. The angular incisura and the cardia were formed at CS18. The change in the angular incisura angle was approximately 90° during CS19 and CS20, and was <90° after CS 21. The prominent formations of the fundus and the pylorus differentiate at around CS20. Morphometry of the stomach revealed that the stomach gradually becomes "deflected" during development. The stomach may appear to move to the left laterally and caudally due to its deflection and differential growth. The track of the reference points in the stomach may reflect the visual three-dimensional movement. The movement of point M, representing the movement of the greater curvature, was different from that of points C (cardia) and P (pyloric antrum). The P and C were located just around the midsagittal plane in all the stages observed. Point M moved in the caudal-left lateral direction until CS22. Moreover, the vector CP does not rotate around the dorsoventral axis, as widely believed, but around the transverse axis. The plane CPM rotated mainly around the longitudinal axis. The data obtained will be useful for prenatal diagnosis in the near future.

Morphometric development of sphincter of oddi in human fetuses during fetal period: microscopic study

OBJECTIVE

In this study, morphometric developments of the sphincter of Oddi in human fetuses were observed.

MATERIAL AND METHODS

We observed 113 human fetuses consisting of 67 male and 46 female subjects, whose ages varied between 14 to 40 weeks who showed no signs of any pathology or anomaly externally. The common external measurements of fetuses were carried out, followed by abdominal dissection to determine where the sphincters of Oddi were localized within the duodenum and pancreas. Histological specimens of tissue samples were gathered from the inner wall of the duodenum where it was assumed that the sphincters of Oddi had been localized. The parameters of total external diameters, lumen diameters, wall thickness, diameters of ductus choledochus and ductus pancreaticus, and the distance between these two structures, which are also known as the origins of the sphincter of Oddi, were measured by using a light microscope. The standard deviations of the measurements were calculated for each gestational week and trimester.

RESULTS

The calculations suggested that there were statistically significant correlations between gestational age and all of the other parameters with the exception of the ductus choledochus (p<0.001). It was observed that the wall thickness of the ductus choledochus increased at the first half of the fetal stage and decreased at the second half, as the lumen diameter increased through the 40th week. The gender difference was not statistically significant (p>0.05).

CONCLUSION

The data we collected in our study were considered as useful for the evaluation of the development of the sphincter of Oddi area and fetal stage.

Anatomical classification of the shape and topography of the stomach

The aim of the study was to present the classification of anatomical variations of the stomach, based on the radiological and historical data. In years 2006–2010, 2,034 examinations of the upper digestive tract were performed. Normal stomach anatomy or different variations of the organ shape and/or topography without any organic radiologically detectable gastric lesions were revealed in 568 and 821 cases, respectively. Five primary groups were established: abnormal position along longitudinal (I) and horizontal axis (II), as well as abnormal shape (III) and stomach connections (IV) or mixed forms (V). The first group contains abnormalities most commonly observed among examined patients such as stomach rotation and translocation to the chest cavity, including sliding, paraesophageal, mixed-form and upside-down hiatal diaphragmatic hernias, as well as short esophagus, and the other diaphragmatic hernias, that were not found in the evaluated population. The second group includes the stomach cascade. The third and fourth groups comprise developmental variations and organ malformations that were not observed in evaluated patients. The last group (V) encloses mixed forms that connect two or more previous variations.