| Abstract [eng] |
Renal vasculature variations are frequently observed and have significant clinical implications, for instance in kidney transplantation. This thesis aims to establish a clear classification of the renal arterial and venous variations, based on existing literature while considering their clinical relevance and embryological basis. The different types and frequencies of these variations are compared to the newly gathered cadaveric dissection data. Furthermore, this pilot data set provides initial insights into the frequency of variations within the Lithuanian population, facilitating comparisons with data from other countries and ethnic groups. To analyse renal variations, a study with donated bodies was conducted at Vilnius University Faculty of Medicine. Autopsy provides an advantage due to its higher accuracy compared to indirect observation via imaging modalities. For data collection, both kidneys, along with their arteries and veins, were examined for anatomical variations. The number, origin, and branching patterns of the renal vessels were recorded and systematically analyzed. These findings were then compared to existing data in the literature to identify similarities, differences, and potential population-specific trends. Within the data set, it was observed that 8 out of 23 renal arteries (34.7%) exhibited no variation, displaying a single renal artery. Among the variations, aortic superior polar arteries (21.7%) were more frequent than their inferior counterpart with 4.3%. Perihilar branching, where the artery bifurcates before entering the kidney parenchyma, occurred in 39.1% of cases, though not considered a true variation. Contrarily, early branching, which was the most frequent variation with 30.4%, is considered an actual variation and of special clinical importance especially for surgical interventions.Lastly, arterial branches from the renal artery supplying the poles of the kidney called perihilar superior and inferior polar arteries, had a frequency of 26% and 0% respectively. Regarding renal vein variations, the left and right kidneys were further distinguished. On the right side 9 out of 11 (81.8%) samples had a single renal vein and 18.2% an additional renal vein. No cases of abnormal reflux and rare type were observed. Variations on the left side were more prevalent, and more variants were distinguished, additionally displaying circumaortic and retroaortic left renal vein as well as late venous confluence. With the exception of the rare type, all variations of the left renal vein were found once, corresponding to a frequency of 8.3%. Consequently, 50% of left renal veins (6 out of 12) showed no variations. The thesis emphasizes that renal variations are common while highlighting their clinical significance. It can be concluded that the development of a standardized classification system for these variations is essential to improve consistency across the literature. Furthermore, additional research is needed to investigate variations across different ethnic groups, including the incorporation of data from Lithuania. |
