Retrocaval ureter is an uncommon congenital abnormality in which the Inferior Vena Cava locates anterior to the ureter and causes its obstruction and hydronephrosis. as a result. and it is also considered one of the rare causes of hydronephrosis. The abnormality almost always occurs on the right because of the physiological position of the Inferior Vena Cava. https://foldlyers.shop/product-category/novelty-products/