Hydronephrosis

Introduction to hydronephrosis As the urine is blocked from the kidneys, accumulating, causing the retention of urine and causing an increase in intrarenal pressure, the renal pelvis and renal pelvis gradually expand, and the renal parenchyma atrophy and destruction, collectively referred to as hydronephrosis. Hydronephrosis is caused by obstruction of the urinary tract and enlargement of the renal pelvis and renal atrophy. The stenosis or obstruction of any part of the urinary tract and the normal dysfunction of the neuromuscular can cause obstacles in the passage of urine, causing obstruction of the urine flow. The upper part of the obstruction is gradually increased due to poor urine discharge, and the lumen is enlarged, eventually leading to hydronephrosis, dilatation, thinning of the renal parenchyma, and renal dysfunction. If bilateral obstruction occurs, uremia occurs, and the consequences are serious. Hydronephrosis can be divided into primary and secondary. basic knowledge Sickness ratio: 0.0001% Susceptible people: no specific population Mode of infection: non-infectious Complications: renal empyema, hypertension

Causes of hydronephrosis

Causes

Hydronephrosis can be divided into primary and secondary, primary hydronephrosis, also known as congenital hydronephrosis, spontaneous hydronephrosis, idiopathic hydronephrosis, the most important cause is renal pelvis Obstruction of the ureteral junction, which is often due to the separation of a large number of collagen fibers in this part of the muscle cells, loses the normal arrangement, can not effectively transmit electrical activity from the pacemaker cells, and block the transmission of normal peristalsis.

Congenital hydronephrosis (40%):

Mostly caused by mechanical obstruction, the main reasons are:

1, ectopic blood vessels: such as vagus blood vessels from the lower pole of the kidney.

2, fiber strips.

3, ureteral renal pelvis high insertion.

4. Obstruction of ureteropelvic junction (UPJO) and valve.

5, local ureteral tortuosity caused by membranous adhesion, congenital hydronephrosis can also be caused by dynamic causes, such as segmental non-dynamic dysfunction.

Secondary hydronephrosis (30%):

Mostly due to other diseases of the urinary system, the primary disease can usually be found through routine examinations. Some diseases require special examinations (such as CT, magnetic resonance imaging, etc.) to confirm the diagnosis. These diseases mainly include:

1, obstructive lesions of the upper urinary tract, tumors, polyps, stones, tuberculosis, inflammation, injury, deformity, diverticulum, renal ptosis.

2, external pressure on the upper urinary tract, abdominal, pelvic or retroperitoneal mass, idiopathic retroperitoneal fibrosis, ectopic blood vessels, ovarian vein compression during pregnancy and menstrual congestion.

3, lower urinary tract obstructive disease, benign prostatic hyperplasia, prostate cancer, urethral stricture, vesicoureteral reflux and so on.

Pathogenesis

The normal function of the urinary system is the formation, storage and discharge of urine. The formation of urine is composed of glomerular filtration, renal tubular secretion and reabsorption. Under normal circumstances, renal pelvic contraction and diastolic coordination action. Therefore, the hydrostatic pressure of the renal pelvis is about 10cmH2O, so that the urine can pass smoothly. When the urinary tract is obstructed, the internal pressure of the renal pelvis can be increased to 50-70cmH2O, on the one hand, the capsule pressure is increased, and on the other hand, the glomerular capillaries are made. The pressure is reduced, whereby the filtration pressure of the glomerulus is reduced until it stops, and the back pressure of the urine causes the distal end of the renal tubule to expand, the proximal end is degenerated, and the original secretion and reabsorption function is lost, and the blood vessel is affected by the increase of the intrarenal pressure. The pressure, especially after the output artery of the glomerulus is compressed, the renal tissue is malnourished, the renal papilla degenerates and shrinks, the convex shape becomes concave, the renal tubular system degenerates, the renal parenchyma becomes thinner, and finally shrinks into fibrous tissue cystic, Observing the obstruction of the ureteropelvic junction with optical and electron microscopy, mainly due to changes in the wall muscles, such as collagen tissue hyperplasia, deposition and fibrous tissue infiltration, which may be caused by local stenosis. The main cause of obstruction, circulatory dysregulation of ureteral contraction, urine retention can also form obstruction, which is the part of patients with hydronephrosis, although the ureteropelvic junction lumen is patency, but can still cause obstruction, renal effusion is not Static, but often circulated, after 2 weeks of water retention, urea in the renal pelvis is significantly reduced, while glucose and chloride are significantly increased, the way of urine reabsorption in the renal pelvis may be:

1, renal venous venous reflux.

2, renal tubular reflux.

3, interstitial reflux.

4, lymphatic regurgitation, so if acute complete obstruction can relieve obstruction within 5 to 6 weeks, kidney function can still be restored, which also suggests that we can not easily decide on the hydronephrosis, especially acute obstruction. Renal resection, whether hydronephrosis continues to develop after obstruction depends on the severity of obstruction (whether the obstruction continues to develop), the adaptability of the renal pelvis (buffering effect) and the rate of urinary flow, if a relative balance is reached, Stop development and stabilize in the stage of mild hydronephrosis.

Hydronephrosis prevention

prevention

Drug health: hydronephrosis is generally not cured by drugs, but in order to prevent secondary infection and protect kidney function, before the treatment of urinary tract obstruction is not made, you can:

1, antibacterial drugs: such as erythromycin, cephalosporin and so on.

2, Chinese medicine treatment: antibacterial Chinese medicine can be used to clear away heat and detoxification, such as Bupleurum, Phellodendron, Astragalus, Psyllium and so on.

Dietary Health: Increase energy intake, but in order to avoid increasing the burden of water on the kidneys, it is not advisable to eat too much protein-rich foods. The energy intake depends mainly on carbohydrates and fat foods.

3, such as unilateral hydronephrosis, do not have to limit the amount of drinking water, if bilateral hydronephrosis, renal dysfunction, to limit the daily intake of water.

Hydronephrosis complications Complications, renal empyema, hypertension

Hydronephrosis can have two major complications, one is the formation of stones, the other is the infection, the infection will aggravate the obstruction, accelerate the damage of renal function, and finally become the kidney empyema, the stone can also make the obstruction and infection worse, thus Mutual promotion, mutual cause and effect, hydronephrosis can also be combined with high blood pressure.

Symptoms of hydronephrosis common symptoms low back pain, abdominal mass, high blood pressure, abdominal distension, dull pain, polyuria, vas deferens, rough nausea, renal pelvis, dilatation, low fever

Symptoms and signs

Most patients are 20 to 40 years old, no obvious symptoms of prostate seminal vesicle tuberculosis, occasional discomfort in the perineum and rectum, severe seminal vesicles, prostatic tuberculosis often manifested as decreased semen, pus, blood, long-term infertility, epididymal tuberculosis usually begins Induration, painless, slow growth, swelling of the lesion develops a cold abscess, adhesion to the skin of the scrotum, collapse to form a sinus path, long-term unhealed, out of the thin yellow pus, bilateral epididymal tuberculosis accounted for about half, bilateral lesions no semen sperm.

1, low back pain: for persistent dull pain or bulging discomfort.

2, waist and abdomen mass: starting from the edge of the costal margin, gradually extending to the side of the abdomen and waist, the larger can cross the midline for a smooth surface cystic mass, marginal rules, fluctuations, tenderness is not obvious.

3, hematuria: generally for microscopic hematuria, complicated by infection, hematuria after stones or trauma.

4, oliguria or no urine: If the bilateral kidneys, isolated kidneys or only one side of the functional kidneys have accumulated water, accompanied by severely impaired renal function, there is oliguria or no urine.

5, oliguria and polyuria alternately: seen in a part of patients with primary hydronephrosis, the mass can be suddenly reduced after a large amount of urination, pain relief, when the urine output is reduced, the mass rapidly increases, the pain is aggravated.

6. Hypertension: About one-third of patients with severe hydronephrosis have high blood pressure, which is mild or moderate, which may be caused by renal parenchymal ischemia caused by dilated renal pelvis and renal artery.

7, spontaneous renal rupture: in the case of non-invasive, due to secondary infection caused by renal pelvis ulceration, resulting in peri-renal hematoma and urinary extravasation, manifested as sudden lumbar abdominal pain, a wide range of obvious tenderness with muscle tension.

8. Fever: The body temperature rises during secondary infection.

9, gastrointestinal symptoms: may have abdominal pain, bloating, nausea, vomiting, the above symptoms are aggravated after drinking plenty of water.

10, bilateral renal obstruction, chronic renal insufficiency, uremia.

Hydronephrosis often has no typical clinical manifestations, mainly manifested as the symptoms and signs of primary disease. When diagnosed with hydronephrosis, the presence of hydronephrosis should be clarified first, and then the cause of hydronephrosis, lesion location, and degree of obstruction should be ascertained. With or without infection and renal dysfunction, through comprehensive and detailed medical history collection, analysis of symptoms and signs, as well as comprehensive analysis of laboratory and various imaging examinations, more can be clearly diagnosed.

Examination of hydronephrosis

1, urine routine examination

Red blood cells and proteins often appear after the enlargement of the renal pelvis.

2, renal function test

Including urea nitrogen, creatinine determination and clearance test, when bilateral renal hydronephrosis is severely impaired, serum creatinine and urea nitrogen are elevated.

3, imaging examination

(1) X-ray urinary tract plain film: can show enlarged kidney shadow and stones.

(2) B-ultrasound: This method is simple and convenient, no damage, the detection of water volume and renal cortical thickness are accurate, and can be initially differentiated from renal cysts and kidney tumors. The criterion for judging the degree of hydronephrosis by B-ultrasound Yes: Early accumulation of water: no obvious change in ultrasound image, mild water accumulation: banded oval or diamond-shaped echo zone in the renal sinus, substantial changes are not obvious, moderate water: renal sinus is typical glove-like, pipe Shape-like or wheel-shaped anechoic zone, substantially thinner but larger than 1/2 of normal thickness, severe water accumulation: there is a large multi-sac vesicular echo-free zone in the renal sinus, which is obviously thinner but larger than normal 1/4. Extremely heavy water: The echo-free area in the renal sinus is huge cystic or incompletely separated, and the substance is thin and difficult to distinguish.

(3) Color Doppler ultrasound: The hemodynamic changes of the affected kidney were measured by measuring the intra-arterial arteriovenous blood flow spectrum. The measurement parameters were systolic value (SV) and resistance index (resistant index, RI), SV mainly reflects renal vascular filling degree and blood flow supply intensity, RI reflects the resistance state of renal blood vessels, related to vascular elasticity and renal interstitial changes, and also related to renal blood flow, diagnosing obstruction with RI>0.7 as standard The sensitivity of hydronephrosis was 92% and the specificity was 88%.

(4) IVU venous urinary angiography:

Can understand the side or bilateral hydronephrosis, the location of obstruction, the degree of obstruction (partial or complete), etc., when the water seriously affects the renal function of the affected side may develop poorly, high dose IVU and delay the filming time, It can be found that the renal pelvis and pelvis are dilated and inflated. The upper urinary tract obstructive diseases that can be diagnosed by IVU are: 1 urinary tract intraluminal diseases: such as kidney and ureteral calculi, which is a method for the diagnosis of urolithiasis. 2 obstruction caused by urinary wall disease: such as renal and ureteral epithelial tumors, tuberculosis, ureteral valves and polyps. 3 obstruction caused by extra-oral disease of urinary tract: For example, IVU can also judge the functional status of kidney according to the degree of shade and hydronephrosis developed by the collecting system.

(5) Retrograde pyelography:

Insert the ureteral catheter into the obstruction, and quickly push the contrast agent to show the location of the obstruction. The nature, such as severe water accumulation, can preserve the ureteral catheter drainage urine after retrograde angiography to relieve the renal function of the affected side for further treatment.

(6) Kidney puncture angiography:

Applicable to patients with unsatisfactory IVU development and failure of retrograde pyelography, the renal pelvis has an elliptical dilatation and a smooth edge. The mild hydronephrosis has a cup-shaped mouth full of sputum, and the heavy water is round and swollen like a cotton peach. Thinning.

(7) CT:

Can clearly show the size of the kidney, contour, renal parenchyma, hydronephrosis and urinary tract lesions, CT enhanced angiography, can understand the kidney function, the identification of kidney lesions.

(8) MRI:

For renal dysfunction, contrast agent hypersensitivity, obstructive lesions to avoid interventional infection and patients can not tolerate IVU, MRI urinary tract angiography can be performed, using urine as a strong signal in T2 weighting, the urinary tract system can be crowned, Sagittal and transverse scans are of great value in the diagnosis of obstruction sites and properties.

(9) renal pelvic perfusion test:

A case for diagnosing urinary tract obstruction that is difficult to determine is a valuable examination method in recent years.

4, kidney map

Obstructive renal curve, if the diuretic kidney map is used to determine whether there is a clear obstruction and whether surgery is needed, the method is to drink water and intravenous furosemide (0.5mg/kg) after routine renal examination. After the kidney diagram, the following results may appear: the two results are normal curves, indicating that there is no obstruction, the conventional kidney map has obstruction and the diuretic kidney diagram is normal, indicating that there is still compensatory emptying after upper urinary tract obstruction, or It is suggested that the upper urinary tract dilatation may be caused by renal pelvis and ureteral smooth muscle tension. The normal renal diagram is normal and the diuretic kidney diagram is obstructive curve, indicating that there is potential obstruction. Both are obstructive kidney diagrams, which are true obstruction. .

Diagnosis and differential diagnosis of hydronephrosis

diagnosis

Diagnosis can be based on medical history, clinical symptoms, and laboratory findings.

Differential diagnosis

1, polycystic kidney disease: the age of onset is 40 to 60 years old, more than half of the patients with hypertension, one or both upper abdomen can touch the cystic mass, but the surface of the mass is multiple cystic nodules, no fluctuation, IVU showed that the renal pelvis and renal pelvis were stretched or deformed without dilatation. Ultrasonography and radionuclide renal scan showed increased renal volume on both sides. There were multiple round cyst images in the kidney area. CT examination showed double kidney enlargement and renal parenchyma. Most of the cystic masses with smooth edges and different sizes can be seen inside.

2, simple renal cyst: when the volume increases, often can touch the cystic mass, ultrasound examination shows that the kidney has a single edge of the round circular sound-transparent dark area, IVU shows renal pelvis and renal pelvis compression, deformation, displacement but no water CT examination showed a thin wall with a clear boundary and a low-density mass. After the enhancement, the density of the renal parenchyma increased and the mass did not increase.

3. Peripheral cysts: cystic masses with unclear borders may appear at the waist. The mobility of the masses is poor, and the sense of fluctuation is not obvious, but there is often a history of trauma. IVU shows that the kidneys are reduced and displaced, but the renal pelvis and renal pelvis are normal without expansion. Ultrasound examination revealed a darkened area around the kidney.

4, adrenal cysts: a large cystic mass can be found in the waist, X-ray plain film can be seen in circular calcification, IVU shows kidney movement and renal axis pressure displacement, renal pelvis and renal pelvis without deformation, dilatation, retroperitoneal angiography, ultrasound examination CT examination showed images of cystic masses in the adrenal area.

5, mesenteric cyst: the abdomen can touch the cystic mass with clear edges, but the mass is shallower and moves to the left and right, with intestinal obstruction symptoms, gastrointestinal tract barium meal X-ray examination has signs of compression.

6, pancreatic cyst: the left upper abdomen can touch the cystic mass with unclear margin, but often accompanied by abdominal trauma or acute pancreatitis history, more common in adults, no urinary system performance, urine sugar test positive, gastrointestinal bowel meal X-ray examination There are signs of compression.

7, hepatic cyst: right upper abdomen or xiphoid can touch cystic mass, but the cyst position is superficial, easy to touch, tenderness is more obvious, without urinary system symptoms, ultrasound examination and radionuclide liver scan showed cyst signs.

8, horseshoe kidney: the abdominal umbilical area touches a uniform and substantial mass, accompanied by hydronephrosis can reach irregular cystic mass, but IVU shows the kidney axis is inverted eight-shaped, the middle can be seen connecting the shadow of the isthmus of the two kidneys, two The lateral renal pelvis is at a lower position and closes toward the midline, and the renal pelvis extends to the medial side.

9, normal pregnancy often mild kidney, ureteral water in addition to pregnancy uterus compression ureter, is due to the secretion of progesterone during pregnancy caused by renal ureter muscle relaxation, which is a physiological change, due to anatomical relationship, almost Both happen to the right.

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