Individual anatomic variability of the renal pyelocaliceal system and upper urinary tract in the fetal period of human otogenesis

Abstract

Background. The study of the individual anatomical variability of the kidneys and upper urinary tract in the fetal period of intrauterine development (IUD) will clarify the etiology and form a clear idea of the causes and timing of the structure and possible occurrence of congenital malformations of the urinary system. Objective. To find out the features of individual anatomical variability of the renal pyelocaliceal system in the fetal period of human ontogenesis. Methods. 102 specimens of human fetuses 160.0-480.0 mm of parieto-calcaneal length (PCL) (4-10 months of IUD) were studied. A set of morphological examination methods was used, which included anthropometry, morphometry, vascular injection, X-ray techniques, preparation and statistical analysis. Results. Among the variants of the structure and congenital defects of the upper urinary tract on our material (specimens of human fetuses) found doubling of the renal pelvis and ureters (4); bends of the pyeloureteral segment and megaureter (2); polymegacolyx and megacolyx (2); aberrant renal vessels (8). In our opinion, the main role in the occurrence of congenital hydronephrosis belongs to defects in the development of the upper urinary tract and vasoureteral conflicts, in which close syntopic connections of the renal pelvis and proximal ureter with abnormal vessels can cause urodynamic disorders. Conclusion. 1. In our material, 15.7% of fetuses revealed variants of structure and topography, as well as defects in the development of the upper urinary tract. 2. In female fetuses the revealed variants and anomalies of structure and topography prevailed those in male sex in the ratio 5: 3. 3. Variants of the structure of renal vessels and their syntopy with the renal pelvis and ureter in all observations were a potential danger of vasorenal conflicts, which would further lead to hydronephrotic transformation of the kidney.