Horseshoe kidney

　　During embryonic development from 4 to 6 weeks, the posterior kidney tissues approach each other, at this time, many influencing factors can lead to the fusion of the lower poles. Minor changes in the umbilical artery or iliac artery can cause the direction of the migrating kidneys to change, leading to the fusion of the two kidneys. Regardless of the formation mechanism, the fusion of the kidneys always occurs before rotation, so the kidneys and ureters often face forward.

　　Patients may experience upper abdominal, umbilical, or lumbar pain, chronic constipation, and urinary system symptoms such as chronic nephritis, pyelonephritis, hydronephrosis, and stones. 80% of cases may develop hydronephrosis. Severe cases may have the possibility of urinary tract obstruction accompanied by severe flank pain and other symptoms.

　　Some patients may have no symptoms at all. Most patients develop symptoms due to compression of the plexus, blood circulation, or ureter, resulting in upper abdominal, umbilical, or lumbar pain, chronic constipation, and urinary system symptoms such as chronic nephritis, pyelonephritis, hydronephrosis, and stones. 80% of cases may develop hydronephrosis. Severe cases may have symptoms such as urinary tract obstruction and severe flank pain.

　　During embryonic development from 4 to 6 weeks, the posterior kidney tissues approach each other, at this time, many influencing factors can lead to the fusion of the lower poles. Therefore, it is important to make a prenatal diagnosis and pay attention to the protection of the kidneys.

　　1. Urinary tract plain film and contrast study:According to the proximity of the renal shadows to the spine and the lower position, the long axes are parallel or the upper pole tilts outward while the lower pole tilts inward.

　　The medical image of horseshoe kidney can suggest the condition as soon as it is near, and sometimes the outline of the isthmus connecting the lower pole of the kidney can be seen. Urinary tract造影 can make an accurate diagnosis, the most prominent sign being the lower renal pelvis pointing towards the midline, the long axis of the renal pelvis and calyces extending from the upper end outward to the lower end inward in an inverted 'eight' shape, and the ureter moving closer to the midline.

　　2, Ultrasound:It can clearly show that the lower poles of the two kidneys are connected, crossing in front of the inferior vena cava and abdominal aorta.

　　3, CT:It can directly display the fusion part of the lower poles of the two kidneys, the isthmus crossing in front of the aorta, and due to poor renal rotation, the renal calyces are located in front of the kidney, and the ureters descend through the front of the isthmus on both sides. However, the position of the horseshoe kidney is generally lower, and it needs to be scanned to a lower position to make a diagnosis.

　　4, IVU:It can show that the kidney position is lower than normal, with the shadow of the two renal pelvises hanging down, close together, and the renal axis tilting from the outer upper to the inner lower direction. The two ureters cross in front of the isthmus and may have obstruction manifestations.

　　5, MR and Radionuclide:The fusion of the lower poles of the two kidneys can be displayed in a coronal view.

　　In addition to routine treatment, horseshoe kidney patients should also pay attention to the following aspects in diet: high-nutrition, easily digestible foods. Reasonable dietary搭配 should be maintained. It is also advisable to avoid spicy and irritating foods.

　　Generally, there is no need for treatment for asymptomatic and complication-free individuals. Those with symptoms such as urinary tract obstruction, severe lumbar and costal pain, and those affected by work and life, may consider ureterolysis, sectioning and separation of the two kidneys and the pelvis and ureteroplasty and fixation. Individuals with complications need to be treated according to specific circumstances, such as pelviureteral junction obstruction, which requires pelvioplasty surgery. The surgery generally uses a standard lumbar incision, and care should be taken to separate and not damage the abnormally distributed renal vessels when displaying the kidneys. It is often possible to find the renal vein crossing the pelviureteral junction, which should be ligated and cut to relieve the obstruction here. The ureter often opens at a high position in the pelvis, and it should be fully mobilized and exposed below the pelviureteral junction for Y-V pelvioplasty, widening the junction and ensuring unobstructed flow. If there is vesicoureteral reflux, a vesicoureteral reanastomosis should be performed. This disease is rarely treated with simple isthmus sectioning surgery because it has little effect on improving drainage, correcting the position of the kidneys and ureters. When choosing ESWL for horseshoe kidneys with stones, it is necessary to pay attention to the situation of stone fragments being excreted, and it can be advised to adopt different positions to promote the excretion of stone fragments.