Primary vesicoureteral reflux

　　1. The most common primary cause is congenital incomplete mechanism of bladder ureteral valve, including congenital short or horizontal ureteral submucosal ureter, abnormal ureteral orifice, thin and weak trigone muscle tissue of the bladder, Waldeyer's sheath congenital abnormality, etc. 53% of the cases are due to detrusor dysfunction causing reflux.

　　2. Pathophysiological pathogenesis: The pathogenesis of RN has not yet been elucidated, and renal damage caused by VUR may be due to multiple factors.

　　3. Bacteriuria The reflux of urine brings bacteria into the kidney, and the damage to the renal tissue is considered to be the consequence of direct invasion.

　　4. Urodynamics changes Due to the fish mouth shape of the ureteral orifice, large reflux volume, even without infection, when the intrapelvic pressure reaches 40 mmHg, IRR can occur, leading to renal damage. Participating urine is one of the most important results of VUR, and the residual urine volume may play an important role in the etiology of UTI recurrence.

　　5. Urine input into renal tissue Urine leaks into the renal interstitium through the Bellin tube or the break in the fornix angle of the renal papilla, or through the renal sinus. Urine in the renal interstitium can directly stimulate or lead to inflammation or fibrosis through an autoimmune reaction (the antigen may be bacteria in urine or Tamm-Horsfall protein).

　　6. Renal intravascular stenosis Due to urine leakage into the interstitium outside the renal tubules and capillaries and vasa recta, inflammation and fibrosis cause renal intravascular occlusion and stenosis. This further leads to renal ischemic lesions and secondary hypertension. Additionally, when functional urinary tract obstruction is present, bladder and urethral pressure increases, leading to increased renal tubular pressure and IRR, followed by decreased glomerular filtration rate, reduced blood flow in the efferent arterioles, and the formation of renal defects, leading to interstitial nephritis.

　　7. Glomerulosclerosis In recent years, the focal segmental glomerulosclerosis of RN has attracted attention. Lotran (1982) summarized its pathogenesis as: immune damage, insufficient mesangial function after uptake of macromolecular substances, renal vascular lesions, and glomerular hyperfiltration.

　　8. Genetic factors Some believe that 10% to 20% of VUR is related to genetics, and 40% of first-degree relatives in susceptible families have reflux.

　　1. Frequent urination, urgency, dysuria, and lower back pain, fever.

　　2. Physical examination may show unilateral or bilateral renal area tenderness and percussion pain; if there is a significant amount of renal积水, an abdominal mass may be palpable.

　　3. In cases where both sides have severe renal impairment due to bilateral vesicoureteral reflux, symptoms of uremia may occur: anemia, edema, poor appetite, etc.

　　I. In the examination, bladder ureteral reflux can generally be divided into five grades.

　　1. Grade: Reflux only reaches the lower segment of the ureter.

　　2. Grade: Reflux to the renal pelvis and calyces without expansion.

　　3. Grade: Reflux with mild to moderate renal pelvis expansion.

　　4. Grade: Marked expansion of the renal pelvis and calyces, and curved ureters.

　　5. Grade: Severe expansion of the renal pelvis and calyces, loss of papillary shape of the calyces, and tortuous ureters.

　　II. Due to the mild degree of reflux, there may be no symptoms at all.

　　1. Recurrent symptoms of urinary tract infection and pyelonephritis: frequent urination, urgency, dysuria, and lower back pain, fever.

　　2. Physical examination may show unilateral or bilateral renal area tenderness and percussion pain; if there is a significant amount of renal积水, an abdominal mass may be palpable.

　　3. In cases where both sides have severe renal impairment due to bilateral vesicoureteral reflux, symptoms of uremia may occur: anemia, edema, poor appetite, etc.

　　1, Mild vesicoureteral reflux has a natural regression tendency. Congenital vesicoureteral reflux during childhood, if the condition is mild or stable, it is advisable to observe and treat, as the reflux may naturally regress with age growth.

　　2, For unilateral reflux patients, if the kidney function on the affected side is severely damaged and the kidney function on the contralateral side is good, nephrectomy on the affected side can be performed.

　　3, Use drugs based on the bacteria from urine culture and drug sensitivity test, and it is advisable to start early and in sufficient quantity to ensure infection control.

　　4, Use drugs with low nephrotoxicity as much as possible.

　　5, Adjust the dose change according to the indicators of renal function.

　　One, Laboratory examination

　　During UTI, urinalysis shows pyuria and positive urine bacterial culture. During RN, urine examination may reveal protein, red blood cells, leukocytes, and various casts. Renal function tests are normal or abnormal.

　　Two, Ultrasound examination

　　Through ultrasound, the function of the bladder ureteral junction can be estimated, the dilation, peristalsis of the ureter, and the continuity of the bladder base can be observed, and the morphology and parenchymal changes of the pelvis and kidney can be observed. Some people insert a catheter during ultrasound and inject gas (such as CO2), if the gas enters the ureter, VUR can be diagnosed. Recently, color Doppler ultrasound is used to observe the function of the junction and the position of the ureteral orifice. However, ultrasound has limitations in detecting upper pole scars and cannot be used for grading VUR.

　　Three, X-ray examination

　　1, Voiding cystourethrography (MCU): This is a commonly used basic method and 'gold standard' for diagnosing and grading VUR. The five-level classification method proposed by the International Reflux Committee: Grade I: Urinary reflux is limited to the ureter; Grade II: Urinary reflux to the ureter, pelvis, but without dilation, renal calyx dome is normal; Grade III: Mild to moderate dilation and (or) torsion of the ureter, moderate dilation of the pelvis, dome without (or) slightly blunt; Grade IV: Moderate dilation and torsion of the ureter, moderate dilation of the pelvis and calyx, dome angle completely disappeared, most calyces retain papillary indentation; Grade V: Severe dilation and torsion of the ureter, severe dilation of the pelvis and calyx, most calyces do not show papillary indentation.

　　2, Intravenous pyelography (IVP): It can further confirm the presence of renal atrophy and the formation of renal scars. In recent years, it is believed that high-dose intravenous pyelography combined with X-ray section photographs can better show scars.

　　Four, Radionuclide examination

　　1, Radionuclide cystography: It is divided into direct and indirect methods, used for determining VUR.

　　2, DMSA scanning technology: It is the only 'gold standard' for diagnosing renal scarring in children, especially those over 5 years old. Coldraich classifies renal scars into four grades based on DMSA scanning imaging signs: Grade I: One or two scars; Grade II: More than two scars, but the renal parenchyma between scars is normal; Grade III: Diffuse damage to the entire kidney, with obstructive nephrotic kidney manifestations, that is, complete renal atrophy, with or without scars in renal contour; Grade IV: End-stage, atrophic kidney, almost no or no DMSA uptake (less than 10% of the total renal function).

　　1. Rational diet: diet should be light and avoid spicy and irritating foods.

　　2. Supplement vitamin intake: adequate intake of vitamins and trace elements. Vitamin B, vitamin C, and zinc, calcium, iron, etc., can play a protective role in the kidneys.

　　3. Appropriate diet: high-fiber diet is beneficial to maintain smooth defecation, toxin excretion, and balance of human metabolism. Patients with kidney disease should eat more coarse grains, such as corn flour, buckwheat flour, taro, seaweed noodles, certain fruits and vegetables, etc.

　　First, medical treatment

　　1. I, II degree: treat infection and take long-term medication for prevention. SMZCo can be used, calculated at SMZ 5-10mg/Kg, TMP 1-2mg/kg, taken at bedtime, and taken continuously for more than a year. Preventive infection is effective, and urine culture should be performed once every 3 months, and radionuclide examination or voiding cystography should be performed annually to observe the degree of reflux, and intravenous urography should be performed every two years to observe the formation of kidney scars. After the reflux disappears, urine culture should still be performed every 3-6 months because the reflux can be intermittent. In addition, it should be encouraged to drink water, urinate twice before bedtime to reduce intravesical pressure, maintain normal defecation, and defecate on time.

　　2. III degree: the treatment is the same as I and II degrees, but the reflux should be checked every 6 months, and intravenous pyelography should be performed annually.

　　3. IV, V degree: surgery correction should be performed after preventive medication.

　　Second, surgical treatment

　　The surgical treatment methods for VUR are mostly plastic surgery. The indications for surgery are:

　　1. IV degree and above reflux.

　　2. For those with less than III degree, initial medical observation and treatment should be given, and surgery should be performed if there is persistent reflux and the formation of new scars.

　　3. Recurrent urinary tract infections that have not improved after 6 months of active treatment.

　　4. And those with urinary tract obstruction.

　　In foreign countries, injection therapy is popular, this method only requires short-term anesthesia, and needs short-term hospitalization or does not require hospitalization, which is easy for parents to accept.