CLINICAL CONSIDERATIONS OF KIDNEYS
A. ROTATION OF THE KIDNEY. During the relative ascent of the kidneys in fetal development, the kidneys rotate 90 degrees medially so that the renal hilus is normally orientated in a medial direction.
B. ASCENT OF THE KIDNEY. The fetal metanephros is located in the sacral region, whereas the adult kidneys are normally located at vertebral levels T12–L3. The change in location (i.e., ascent) results from a disproportionate growth of the fetus caudal to the metanephros.
C. HORSESHOE KIDNEY occurs when the inferior poles of both kidneys fuse during fetal development. The horseshoe kidney gets trapped behind the inferior mesenteric artery as the kidney attempts to ascend toward the normal adult location.
D. KIDNEY TRAUMA. Kidney trauma should be suspected in the following situations: fracture of the lower ribs, fracture of the transverse processes of lumbar vertebrae, gunshot or knife wound over the lower rib cage, and after a car accident when seat belt marks are present. Right kidney trauma is associated with liver trauma, whereas left kidney trauma is associated with spleen trauma. Clinical findings include flank mass and/or tenderness, flank ecchymosis, hypotension, and hematuria. One of the absolute indications for renal exploration is the presence of a pulsatile or expanding retroperitoneal hematoma found at laparotomy.
E. SURGICAL APPROACH TO THE KIDNEY. An incision is made below and parallel to the 12th rib in order to prevent inadvertent entry into the pleural space. The incision may be extended to the front of the abdomen by traveling parallel to the inguinal ligament.