There are two types of horseshoe-shaped kidneys
1, fused kidney Fused kidney (fused kidney) is the fusion of the two sides of the kidneys, there are various types, such as horseshoe-shaped kidneys, disk-shaped kidneys, sigmoidal kidneys, block kidneys and so on, the most common of which is the horseshoe-shaped kidneys.
2, horseshoe-shaped kidney horseshoe-shaped kidney (horseshoe kidney) that is, one pole of the two sides of the kidney can be fused with each other before the spine or before the abdominal blood vessels, about 90% of the cases is the lower pole fused with each other, called the horseshoe-shaped kidney (Figure 27-10). The fused portion, called the isthmus, is composed of renal parenchyma or connective tissue and is located before the abdominal aorta and inferior vena cava and above the bifurcation of the abdominal aorta. The kidney is lower than normal, the renal pelvis cannot rotate properly because of the restriction of the fusion, and the ureter passes downward in front of the fused isthmus, which is susceptible to fluid retention, infection, and stone formation due to poor drainage. There is 1 case in every 300-1000 autopsies, mostly in males. Clinically there is 1 case in about 400 people.
The horseshoe-shaped kidney is a congenital anomaly of the kidney, the main symptom is due to the plexus or ureteral compression and the emergence of periumbilical pain or gastrointestinal symptoms, in the pediatric can be completely asymptomatic, but also misdiagnosed as abdominal tumors, so the need for differential diagnosis. Horseshoe-shaped kidney can be complicated by serious malformations of other systems, such as cardiovascular or neurological malformations. Asymptomatic people with horseshoe-shaped kidney do not need to be treated, and those who have symptoms of compression can cut off the isthmus with surgery. If one side of the kidney suffers from serious diseases such as tuberculosis and tumor, the affected side should be resected. If one side has congenital hydronephrosis and obstruction of the pelvic-ureteral junction, the affected side can be dissected for pyeloplasty.