horseshoe kidney
Introduction
Horseshoe Kidney Introduction Horseshoe-shaped kidneys are the most common type of fused kidney deformity, and the lower poles of the two kidneys are caused by a substantial isthmus or fibrous isthmus that traverses the midline. This disease was first discovered by Decarpi at the autopsy in 1521. Botallo (1564) gave a comprehensive description and illustrated, and Morgagni (1820) reported the first case of a horseshoe kidney with complications. The incidence of horseshoe-shaped kidneys is very low, and one in about 400 newborns is mostly male. The incidence rate in the normal population is about 0.5%, the ratio of male to female is 2:1, clinically all ages, but more common in children at autopsy. Mainly due to the congenital anomalies of horseshoe-shaped kidney patients with other systems, some of which are prone to early death, and the evidence of familial inheritance of horseshoe-shaped kidneys is insufficient. basic knowledge Sickness ratio: 0.0001% Susceptible people: more often in newborns or babies Mode of infection: non-infectious Complications: Down syndrome in children Hypospadias Bladder ureteral reflux
Cause
Horseshoe kidney disease
Dysplasia (30%):
After 4 to 6 weeks of embryonic development, the posterior kidney tissues are close to each other. At this time, many influencing factors can lead to the fusion of the lower poles. A slight change in the umbilical artery or brachial artery can cause a change in the direction of the kidney that is moving, resulting in the fusion of the two kidneys. Regardless of its formation mechanism, kidney fusion always occurs before rotation, so the kidneys and ureters often face forward.
Pathogenesis
More than 95% of the patients have their kidneys fused in the lower pole, and a few have an upper pole fusion. The usually connected isthmus is composed of a renal parenchyma with blood supply, and occasionally only a few fibrous structures connect the two kidneys. Mostly located at the waist 3 or waist 4 level, sometimes even behind the bladder in the pelvic cavity. As mentioned earlier, due to poor rotation of the kidneys, the direction of the renal pelvis is forward, but the number is generally normal. The blood supply varies greatly, and the lower part and its adjacent kidney tissue can accept branches from the main trunk of the renal artery, or it can have its own separate blood vessel supply.
Prevention
Horseshoe kidney prevention
Because horseshoe-shaped kidney patients are complicated with congenital anomalies in other systems, some of them are prone to early death. There is insufficient evidence for the familial inheritance of horseshoe-shaped kidneys. Even if there are no symptoms, they are often found to be complicated by other congenital abnormalities. Therefore, prenatal examinations are carried out regularly to prevent them. Perinatal ultrasonography can detect abnormalities before birth, and its imaging findings are very easy to diagnose, early detection and early diagnosis and early treatment.
Complication
Horseshoe kidney complications Complications in children with Down's syndrome, hypospadias, vesicoureteral reflux
1. Horseshoe-shaped kidneys are often found to be associated with other congenital anomalies, even without symptoms. Boatman et al. counted 96 patients with horseshoe kidneys, of which about one-third had at least one other system abnormality.
2, many newborns and slightly longer patients have a variety of congenital anomalies. Autopsy results showed that abnormalities in other systems occurred mostly in neonates or infants. The main abnormalities included the skeletal system, cardiovascular system, central nervous system, etc. Anorectal abnormalities were also common.
3, about 20% of children have Trisomyv18 syndrome, 60% of women with Turner's syndrome, double uterus or vaginal mediastinum, 40% of male patients Hypospadias or testicular insufficiency.
4, more than half of patients with vesicoureteral reflux.
Symptom
Horseshoe-shaped kidney symptoms Common symptoms Urinary frequency diarrhea Hematuria Diffuse lower back pain Constipation Puriria Low back pain Lower abdomen mass
Patients can be asymptomatic, misdiagnosed as abdominal tumors, appendicitis, pancreatitis, duodenal ulcers, etc., or due to complications. There are clinical manifestations, can be divided into three types of symptoms:
One is pain in the lower back or umbilicus, the lower abdomen is lumps; the other is gastrointestinal disorders such as bloating, constipation, etc. The third type is urinary tract combined with symptoms such as infection, stagnant water, stones, etc. Pyuria, hematuria and other symptoms.
Because the ureter is open at the high position of the renal pelvis and the renal pelvis is restricted by the renal fusion, it cannot rotate normally. The ureter moves forward when it passes over the fusion part, resulting in poor urine flow, etc., causing hydronephrosis in 80% of cases, and it is easy to cause Infection and stones.
In addition to possible abdominal masses, horseshoe-shaped kidneys often have no peculiar symptoms and clinical manifestations are non-specific. Many abnormalities can be found occasionally in ultrasound or secretory urography. Perinatal ultrasound can detect abnormalities before birth, and its imaging findings are very easy to diagnose.
Examine
Horseshoe kidney examination
Contrast : Excretory urography showed that the renal pelvis and renal pelvis were low in both sides, and the two kidneys were very close to the spine. Therefore, the extension line of the inferior pole was opposite to the normal renal pelvis and crossed in the caudal direction. Due to the poor rotation of the renal pelvis and renal pelvis overlap, even the renal pelvis is pointing to the medial side, the renal pelvis is turned to the lateral side, and the upper ureter is bent outward.
Sometimes the ureter is compressed by blood vessels, fibrous bands or isthmus to cause hydronephrosis. Careful observation shows that the shadows of the kidneys and isthmus with abnormal axes are sometimes seen on the KUB flat sheet.
B-ultrasound : B-ultrasound can detect malformed horseshoe-shaped kidneys.
Renal radionuclide scan : Renal radionuclide scan to understand the presence or absence of renal parenchyma in the isthmus.
Abdominal aortic angiography: Abdominal aortic angiography is very helpful in determining the surgical approach.
Diagnosis
Horseshoe kidney diagnosis
diagnosis
Can be diagnosed based on medical history, symptoms and related examinations
Differential diagnosis
1. Block kidney: relatively rare, may have low back pain and gastrointestinal symptoms. The two kidneys are extensively fused into an irregular lobulated mass, usually rising only to the level of sputum, and many remain in the pelvic cavity. Therefore, in the lower abdomen or pelvic cavity, a substantial mass can be found, and the surface is nodular. Urinary angiography showed that the two kidneys merged into a circular shadow, the position was low, the renal pelvis and renal pelvis were irregular, and the ureter became short. B-ultrasound shows that the two kidneys are in a block-like fusion.
2. Disk-shaped kidney: the upper and lower poles or the inner side of the two kidneys are fused to form a thick, thin, disc-shaped mass in the middle, which is similar to the horseshoe-shaped kidney. But mostly in the anterior or pelvis. Urography showed that the renal shadow was disc-shaped, the renal pelvis and renal pelvis were poorly rotated, and the ureteral path was abnormal. B-ultrasound and CT examination showed a deformed image of disc-shaped fusion of the two kidneys.
3. Sigmoid kidney: It is a fusion of the upper renal pole and the contralateral renal pole, which can touch the mass in the abdomen. Urinary angiography showed that the kidney shadow was "B" shaped, the two kidneys were parallel to the long axis, the renal pelvis and renal pelvis were abnormally rotated, and the renal pelvis was full. B-ultrasound and CT examination showed abnormal images of the two kidneys in a "B" shape fusion.
4. Abdominal tumor: can be expressed as an abdominal mass. However, there are often gastrointestinal symptoms such as abdominal pain and bloating. Digestive tract barium angiography showed intestinal deformation or filling defects; abdominal CT examination revealed abdominal masses; and urography showed normal urinary system.
