congenital megaureter
Introduction
Introduction to congenital giant ureter Congenital giant ureter is due to abnormal development of the ureteral muscle structure (increased ring muscle, lack of longitudinal muscle), leading to functional obstruction of the ureter, severe expansion of the ureter or even renal pelvis, and accumulation of water. The disease is characterized by functional obstruction at the end of the ureter without significant mechanical obstruction. The ureteral dilatation above the obstructive segment is most evident in the pelvic segment, also known as congenital ureteral functional obstruction. basic knowledge The proportion of illness: 0.008% Susceptible people: no specific population Mode of infection: non-infectious Complications: urinary tract infections urethra stones
Cause
Congenital giant ureteral etiology
(1) Causes of the disease
There is no consensus on the etiology. It may be the proliferation of the ureter muscle layer or the imbalance between the muscle bundle and the fibrils in the embryonic development. The lower end of the ureter is close to the bladder. The stenosis is in sharp contrast with the dilated segment. In some cases, the lower end of the ureter can be seen. There are transverse mucosal folds or canvas-like valves.
The distal unpowered giant ureter has no anatomical stenosis, but the proximal end is dilated, and there is no peristaltic function. The microscopic ureteral muscle layer is relatively lacking, the ring muscle hyperplasia, and some the number of intermuscular nerve cells are reduced.
(two) pathogenesis
The pathogenesis of congenital giant ureteral disease has not been fully elucidated. According to histopathological studies, most scholars believe that it may be related to the following:
1. Lack of longitudinal muscles in the distal ureteral wall.
2. The collagen fibers in the muscle layer at the end of the ureter proliferate, which makes the ratio of muscle bundle to collagen fiber imbalance, and the muscle layer is disordered.
3. The ureteral end muscle layer hypertrophy, mucosal or submucosal inflammation, due to the combined effect of one or several factors, the peristaltic function of the ureter is weakened or disappeared, the urine excretion is not smooth, and the pressure in the proximal ureter increases, resulting in Ureteral dilatation and hydronephrosis.
Prevention
Congenital giant ureteral prevention
There is no effective preventive measure for this disease. Early detection and early diagnosis are the key to the prevention and treatment of this disease.
Complication
Congenital giant ureteral complications Complications, urinary tract infection, urethra stones
Common complications include urinary tract infections and stones.
Symptom
Congenital giant ureteral symptoms Common symptoms Painful backache Giant ureteral disease Lumbar mass Kidney water phenomenon Hematuria
There is no specific clinical manifestation of congenital giant ureteral disease. Most of them are treated with backache and pain, and occasionally due to lumbar mass, hematuria, intractable urinary tract infection, and renal insufficiency.
Examine
Congenital giant ureter examination
Urine, white blood cells and pathogenic bacteria can be found in urine tests accompanied by urinary tract infections and stones.
Cystoscopy triangle and ureteral opening position is generally normal, especially in adults, ureteral catheter insertion can be no difficulty, early cases of radiography X-ray film only see the lower part of the ureter is spindle-shaped or spherical expansion; immediately after injection of contrast agent to pull out the ureteral catheter Emptying the film, visible contrast retention and delayed emptying.
In the X-ray film, the contrast agent in the ureter has a reverse convulsion to the kidney.
According to X-ray urography, the morphological changes of the renal pelvis and renal parenchyma can also be observed, so that the degree of damage can be estimated.
Renal pelvis: The renal pelvis can be normal, the cup of the kidney is flat, the mouth of the cup is irregular, the bulge is convex, and the expansion of the renal pelvis is different.
Renal parenchyma: The renal parenchyma can be normal from normal thickness (generally above 2 cm) and between 1 and 2 cm in thickness until the thickness becomes thinner (children under 1 cm, infants under 0.5 cm) and so on.
B-ultrasound: visible ureteral dilatation of the affected side, with or without significant hydronephrosis.
CT and MRI: CT can be seen in the whole process of ureteral dilatation, there may be different degrees of hydronephrosis, stenosis can be seen at the junction of the ureter and bladder, MRI can be seen to expand the ureter, the lower end of the stenosis, may be accompanied by hydronephrosis.
Diagnosis
Diagnosis of congenital giant ureter
Due to the lack of specific clinical manifestations and signs, the diagnosis depends on imaging examination.
Differential diagnosis
Bladder ureteral reflux
Severe vesicoureteral reflux can cause reflux giant ureter, clinical manifestations of back pain and urinary tract infection symptoms, but there is aggravation of low back pain during urination, IVU examination shows the affected side of the kidney, ureteral dilated water, and the following ureter More obvious, during the urinary bladder angiography, the contrast agent can be found to flow into the ureter.
2. Ureteral stones
Lower ureteral stones can cause kidney, ureteral hydrops, secondary infections can have fever, frequent urination, urgency and dysuria, patients may have a history of renal colic, pain accompanied by microscopic or gross hematuria, ureter can be seen on KUB flat film The opaque shadow of the path, urography showed excretion obstruction at the stone site, ureter and hydronephrosis above the obstruction, and negative stones were found by B-ultrasound and CT examination.
3. Ureteral tuberculosis
Can cause ureteral stenosis caused by kidney, ureteral hydrops, but most patients with progressive urinary frequency, urgency, dysuria and hematuria, there is rice soup pyuria, urinary sediment can be found in acid-fast bacilli, urography shows pelvis, kidney The sputum is destroyed, the renal parenchyma is hollow, the ureter is worm-like or bead-like, the stenosis is narrow, and there is often a tuberculosis of the bladder. The cystoscopy can show congestion around the ureteral orifice, edema and ulcer, and tuberculous nodules can be seen.
4. Ureteral cyst
The ureteral cyst is cystic dilatation at the ureteral opening. The opening is small and the urination is poor. It can cause the ureter to dilate. The range of expansion is lower in the lower segment. The severe ureteral dilatation in the whole process. The B-ultrasound shows a round cystic swelling in the bladder. The cystic angiography showed a circular filling defect in the bladder. The cystoscopy showed a round tumor of the ureteral orifice. The surface was smooth, and there was a small round hole intermittently urinating. The size of the cyst changed with urination.
