Horseshoe Kidney: A Vascular Survey With Surgical Significance

During routine cadaveric dissection in a medical school anatomy lab, a 77‐year‐old male was found to have complete fusion of the inferior poles of the kidneys by an isthmus, forming a u‐shaped horseshoe kidney. Although reported rates of horseshoe kidney are as frequent as 1 in 300 with a 2:1 predominance in males, this is the first case that has been discovered in LMU’s anatomy lab. This anomaly, in many patients, goes unnoticed due to its asymptomatic presentation and, if identified, is typically an incidental finding from ancillary testing. In this case, the superior poles of the kidneys were located in approximately normal anatomical positioning with classic right kidney displaced inferiorly in relation to the left kidney; however, the right kidney’s hilum was displaced more inferiorly than was expected. Both kidneys were elongated, extending down to the level of L3–L4 where the isthmus passes inferior to the inferior mesenteric artery. An impression was observed on the anterior surface of the isthmus due to its relationship to the inferior mesenteric artery. Vasculature was documented in this report which showed several unique features. Multiple inferior polar arterial branches were seen branching from the right common iliac artery but were not observed on the contralateral side. Both testicular veins were observed coalescing into the left and right renal veins respectively. The complete vasculature has been documented in this report for future research and evaluation prior to kidney transplantation or resection.