Fetal sigmoid colon mesentery - In relevance in fetal ultrasound application. A pilot study.

INTRODUCTION: Ultrasound examinations during pregnancy are routine procedures used to detect fetal congenital malformations. Ultrasound monitoring of sigmoid colon mesenterial development could be useful for early detection of subjects at risk of sigmoid colon volvulus. OBJECTIVE: The aim of our paper was to assess the sigmoid colon length, and sigmoid colon mesentery width and height in the late fetal period, and, using the results, to estimate the surface area of the mesocolon (in mm2) in living fetuses. Moreover, we attempted to repeat some of these measurements in living fetuses using ultrasound imaging. METHODS: The study was carried out on 209 formalin fixed human fetuses (100 female and 109 male) aged from 4th to 7th gestational months (102-203 days), with a crown-rump length of 132-342mm. The length of the sigmoid colon, as well as the height and width of its mesentery were measured. The surface area of the mesocolon was estimated. Correction for formalin induced shrinkage was applied. Pilot ultrasound examinations of live fetuses were performed. RESULTS: Mean values of sigmoid colon length, mesenteric width and height (formalin fixed fetuses) for respective gestational ages were: month 4: 21.46±6.7mm, 6.80±2.1mm, 5.5±1.49mm; month 5: 27.32±1.2mm, 7.62±2.01mm, 7.33±2.17mm; month 6: 47.56±9.57mm, 11.68±3.8mm, 10.3±3.05mm; month 7: 56.92±17.48mm. 15.32±8 mm, 12.81±3.16mm. The surface area ranges of the sigmoid colon mesentery found for respective gestational months (intrauterine fetuses) were as follows: month 4: 33.24-51.95mm2; month 5: 49.63-77.6mm2; month 6: 106.89-167.15mm2 and month 7: 145.69-272.53mm2. CONCLUSION: The surface area of the sigmoid colon mesentery can be used as a simple parameter applied in fetal ultrasonographic evaluation. The development of the sigmoid colon accelerates in the 6th gestational month, and decelerates in the 7th gestational month. The sigmoid colon mesentery width was larger than its height between the 4th and 7th gestational months.

The morphology of the foetal sigmoid colon in the African population: a possible predisposition to sigmoid volvulus.

AIM: This study aimed to determine the morphological types of the foetal sigmoid colon and establish if the anatomical predisposition to sigmoid volvulus is present in Black African foetuses. Sigmoid volvulus affects Black Africans in our province more frequently than other ethnic groups, and males more than females. Its aetiology remains speculative, with factors being proposed that do not suggest the pathogenetic mechanisms or the gender bias. Previous anatomical studies have suggested that Black Africans have a predisposition to sigmoid volvulus due to an elongated sigmoid colon. We investigated whether this phenomenon occurred during foetal development. METHOD: Foetuses were donated from local hospitals. Population groups were defined as Black African and non-African. After dissection, the anatomy of the sigmoid colon was described according to level of origin, classic or elongated type and shape (broad or narrow). RESULTS: A total of 296 Black African foetuses and 37 non-African foetuses were donated. The sigmoid colon in the majority of foetuses in all gestational age groups had a low level of origin. An elongated colon was seen in 68% of Black African and 17% of non-African foetuses (P < 0.0001). Among Black Africans there was a higher proportion of elongated sigmoid colon among male (73%) than female foetuses (62%) (P = 0.044). In foetuses with an elongated sigmoid colon the broad shape was more common in females than males and the long-narrow shape was more common in males (P = 0.038). CONCLUSION: The elongated sigmoid colon seen in Black Africans is present in utero and occurs more frequently in Black African males. A narrow shape is more common in male foetuses and the broad shape is more common in female foetuses. These anatomical features may be the cause of the predisposition to sigmoid volvulus in Black African adults.

The development of large intestine during the fetal period.

OBJECTIVE: The aim of this study is to determine the colon types, developmental change of the colon morphology during the fetal period. METHODS: The study was realised on 131 human fetuses (male 69, female 62) ages between 10 and 40 weeks, which have no external pathology and anomalies. The colon types were evaluated in two parts. As the first part, the colon part between the ileal orifice and sigmoid colon was typed. The sigmoid colon was typed as the second part. The macroscopic diameters of parts of the colon and the thicknesses of wall layers of ascending and descending colons were measured under the light microscope. RESULTS: For the proximal part of the colon, there were seven types of colon, and there were five types for the sigmoid colon. For the first part, transverse type colon was a rare type during the fetal period (3%). The oblique type colon was observed mostly in the first and second trimester during the fetal period. Adult type colon was the most common type in the third trimester and full-term groups. The pendulous type colon was observed mostly in the third trimester. The development of the haustra and tenia coli in the first trimester was quite slow, but later the development increased more and more, and during the full-term period, the haustra and tenia coli could be seen clearly. CONCLUSION: The percentage distribution of the colon types between the trimesters was significant. It was observed that the maturation of haustra and tenia coli started from the ascending colon and progressed towards the sigmoid colon. The thickness of the tunica mucosa layer both in the ascending and in descending colon part increased considerably in the middle of the second trimester.

Computed tomography of the rectosigmoid region.

Knowledge of the anatomy and embryology of the rectosigmoid region is useful for the correct interpretation of computed tomography in this region. The appearances and differential diagnoses of some of the common conditions affecting this region are presented and discussed.

The fetal presacral pseudo-mass: a normal sonographic variant.

We examined 416 consecutive third trimester intrauterine gestations over a 4-month period and discovered 26 hypoechoic masses in the fetal presacral space (6.3% incidence). These masses varied in diameter from 15 to 30 mm (mean, 21.5 mm). All neonates were normal on follow-up examination, without evidence of any masses or neurologic deficits. The fetal rectosigmoid colon frequently is identified in the third trimester and may reach 2 to 3 cm at term. Because the prevalence of meconium-filled rectum (6.3%) exceeds that of a presacral teratoma (0.0025%), this normal anatomic variant should be considered the most common cause of a third trimester presacral "mass."

Neuronal dysplasia. Considerations for the pathogenesis and treatment of primary chronic constipation in adults.

Intestinal muscle and the autonomic nervous system constitute a neuromuscular unit. A clinical study was undertaken to seek neurogenic causes of impaired motility affecting the rectosigmoid junction and rectum. Patients with primary chronic constipation were shown by enzyme-histochemical examination of biopsies to have neuronal colonic dysplasia of the rectosigmoid, whereas the latter was normally innervated in healthy controls. The present investigations provide a fresh insight, underpinned by histological findings, into the aetiology of chronic constipation and make a contribution to its operative treatment.

Immunocytochemical and electronmicroscopical data on the differentiation of somatostatin-containing endocrine cells in human large intestine.

The distribution and ultrastructure of the somatostatin-containing endocrine cells in the distal large intestine of fetuses, children and adults was investigated by silver impregnation, immunocytochemical and electron-microscopical techniques. Somatostatin-containing endocrine cells in 10-14-week-old fetuses were found to differentiate very intensively. In 19-25-week-old fetuses the frequency of occurrence began to decrease and this tendency was preserved during the subsequent stages of ontogenesis. Conversely, the frequency of occurrence of argyrophil endocrine cells increased. The change in the mean diameters of the secretory granules was also studied.

[Formation of the microcirculatory bed of the muscle coat of the wall of the sigmoid colon during human fetal development]. / Stanovlenie mikrotsirkuliarnogo rusla myshechnoi obolochki stenki sigmovidnoi obodochnoi kishki v plodnom periode u cheloveka.

During intrauterine life microcirculatory bed of the muscular coat is forming and developing in accordance with its differentiation, growth and functional changes at various steps of its ontogenesis. This step-like differentiation in the parts composing the microcirculatory bed and the whole microcirculatory network of longitudinal and circulatory layers of the muscular coat is genetically connected with differentiation taking place in the wall of the sigmoid colon during the developmental period studied and, in the end, reflects morphological maturation of the sigmoid colon at different stages of its individual ontogenesis.

[Morphometric findings in the microcirculatory bed of the sigmoid serosa during the fetal period in man]. / Morfometricheskie dannye mikrotsirkuliatornogo rusla seroznoi obolochki sigmovidnoi kishki v plodnom periode u cheloveka.

During fetal life, formation and arrangement of the microcirculatory bed in the serous membrane of the sigmoid colon correspond to the growth and functioning of the latter at different stages of ontogenesis. Two periods in the development of the microcirculatory bed of the serous membrane of the sigmoid colon are revealed: the first period coincides with the first half of the fetal development when capillary growth is considerable, i.e. with the growth of metabolic part in the microcirculatory bed; the second period coincides with the second half of the fetal development when intensified growth of the sigmoid portion of the large intenstine and its transport sections in the microcirculatory bed (arterioles, precapillaries, postcapillaries, venules) are observed.

Differentiation of intramural ganglia in the dissociated rectosigmoid of the rat: an organ culture study.

The distal rectosigmoid of the developing embryonic rat was studied on each gestational day from 12 to 21. Circular muscle was first recognized on day 16 and ganglion cells on day 17. When in vitro dissociated colon from as early as the day 12 embryo reached a maturational age of 17 days (embryonic age plus days in culture), circular muscle, ganglia, and peristalsis could be detected. This indicates that neuroblasts must have migrated to the indifferent mesenchyme before day 12 of gestation. Anti-nerve growth factor immunoglobulin-G ( IgG) did not inhibit differentiation of ganglia in vitro. As a result of this study we designed an in vitro assay that can serve as a useful means to study isolated ganglion cell development.