Study of the ureter structure in anencephalic fetuses

Abstract

Purpose: The objective of this paper is to analyze the structure of the ureter in normal and anencephalic human fetuses. Materials and Methods:We studied 16 ureters from 8 human fetuses without congenital anomalies aged 16 to 27 weeks post-conception (WPC) and 14 ureters from 7 anencephalic fetuses aged 19 to 33 WPC. The ureters were dissected and embedded in paraffin, from which 5 µm thick sections were obtained and stained with Masson trichrome, to quantify smooth muscle cells (SMC) and to determine the ureteral lumen area, thickness and ureteral diameter. The samples were also stained with Weigert Resorcin Fucsin (to study elastic fibers) and Picro-Sirius Red with polarization and immunohistochemistry analysis of the collagen type III fibers to study collagen. Stereological analysis of collagen, elastic system fibers and SMC were performed on the sections. Data were expressed as volumetric density (Vv-%). The images were captured with an Olympus BX51 microscope and Olympus DP70 camera. The stereological analysis was done using the Image Pro and Image J programs. For biochemical analysis, samples were fixed in acetone, and collagen concentrations were expressed as micrograms of hydroxyproline per mg of dry tissue. Means were statistically compared using the unpaired t-test (p < 0.05). Results: The ureteral epithelium was well preserved in the anencephalic and control groups. We did not observe differences in the transitional epithelium in the anencephalic and control groups. There was no difference in elastic fibers and total collagen distribution in normal and anencephalic fetuses. SMC concentration did not differ significantly (p = 0.1215) in the anencephalic and control group. The ureteral lumen area (p = 0.0047), diameter (p = 0.0024) and thickness (p = 0.0144) were significantly smaller in anencephalic fetuses. Conclusions: Fetuses with anencephaly showed smaller diameter, area and thickness. These differences could indicate that anencephalic fetal ureters tend to have significant structural alterations, probably due to cerebral lesions with consequent brain control damage of ureter nerves.

Anencephaly alters renal parenchymal volume in human fetuses?

“…Recently, Costa et al ( 27 ) studied 17 human fetuses with NTDs and found that urogenital anomalies in human fetuses with NTDs are significant, with an incidence greater than 20%, but did not find severe urogenital anomalies that impair body function. The same group reported that in fetuses with anencephaly, the ureters had smaller diameter, area and thickness, which could indicate that this tissue tends to have significant structural alterations, probably due to cerebral lesions with consequent brain control damage of ureter nerves ( 15 ).…”

“…Pazos et al ( 14 ) found that the bladders of anencephalic fetuses had gross histological alterations when compared to those of normal fetuses. Costa et al ( 15 ) demonstrated differences in the structure of the ureter. Kalaycioglu et al ( 16 ) carried out a stereological evaluation of the kidneys of anencephalic and normal fetuses and found no significant differences between the groups.…”

Neural Tube Defects and Uterus Development in Human Fetuses

“…Recently, the urogenital tract of anencephalic fetuses has been studied, including the kidneys and collecting system [2,3], ureters [4], bladder [5], prostate [6,7], penis [8], testicles [9], female external genitalia [10] and vagina [11]. Some authors have indicated a different response of male and female anencephalic fetuses to hormonal stimulation [12].…”