Challenging Intrarenal Anatomy

While almost everyone has two kidneys, the inner structure of every kidney is not the same. This makes the planning of stone treatment for each patient need to be individualized. Embryologically, while the kidney parenchyma (the metanephric kidney) is developed from the nephrogenic cord (intermediate mesoderm), ureteric bud grows from mesonephric duct. The ureteric bud will grow toward the mesoderm. During the development, the ureteric bud will undergo a series of branching and from the collecting system, including the ureter, the renal pelvis, and calyces. This complicated process resulted in great variation in the collecting system of kidneys, including duplicated system, bifid renal pelvis, as well as variation in caliceal anatomy in individual patients.