Ureteral obstruction

　　The formation of ureteral obstruction is due to various diseases of the urinary system and the lesions of other adjacent organs near the urinary tract. The specific causes are described as follows.

　　1, Urethral lesions:Narrowing of the urethral orifice, urethral stricture, posterior urethral valve, benign prostatic hyperplasia or prostate cancer, urethral injury, urethral foreign body, urethral calculi, etc.

　　2, Bladder lesions:Neurogenic bladder (such as nerve injury caused by congenital meningocele, acquired trauma, drug effects, etc.), bladder calculi, bladder neck tumors, ureteral diverticula, blood clots blocking the bladder, bladder neck stricture, etc.

　　3, Ureteral lesions:Ureteral calculi, tumors, trauma, accidental ligation during surgery, extensive retroperitoneal fibrotic lesions, etc.

　　4, Renal lesions:Renal calculi, renal pelvis tumors, blood clots formed by tumor hemorrhage, congenital stenosis at the renal pelvis-ureteral junction, etc.

　　5, Lesions outside the urinary system causing obstruction to the urinary tract:For example, the compression of retroperitoneal or pelvic masses on the ureter, cervical cancer infiltration into the posterior bladder wall, etc., causing obstruction at the bladder entry site of one or both ureters.

　　The complications of ureteral obstruction are mostly urinary tract infections. The clinical manifestations of lower urinary tract obstruction are mainly progressive difficulty in urination, which may lead to urinary retention and overflow incontinence. Long-term lower urinary tract obstruction can also lead to bilateral renal hydrops and renal insufficiency.

　　Ureteral obstruction is divided into upper urinary tract obstruction and lower urinary tract obstruction, and its specific clinical manifestations are described as follows.

　　The clinical manifestation of upper urinary tract obstruction is pain in the affected side of the waist. When renal hydrops is obvious, a mass can be palpated in the upper abdomen, which may vary in size in intermittent obstruction. Infection may cause fever, pyuria, and some may have symptoms such as frequent urination and urgency. Hematuria may occur with concurrent stones. Bilateral severe renal hydrops can lead to symptoms of chronic renal insufficiency, such as anorexia, nausea, vomiting, and anemia. Bilateral upper urinary tract obstruction may result in anuria.

　　The clinical manifestations of lower urinary tract obstruction are mainly progressive difficulty in urination, manifested as thin urine stream, weak urinary stream, dribbling, incomplete urination, and segmented urination. Subsequently, urinary retention and overflow incontinence may occur. Long-term lower urinary tract obstruction can also lead to bilateral renal hydrops and renal insufficiency.

　　The prevention of urinary tract obstruction must eliminate lower urinary tract obstruction and infection. Such as surgical treatment for urethral stricture and other diseases,根治 urinary tract infection, especially those urea-decomposing bacteria, to avoid bladder foreign bodies, reduce the occurrence of stones.

　　To prevent the occurrence of upper urinary tract stones, urinary tract obstruction factors should be eliminated, such as for congenital urinary tract malformations, active treatment should be given. If narrowing of the prepuce or urethral orifice is found early, it should be removed in time.

　　In cases of trauma and inflammation, inflammation should be controlled in time, urinary tract infections should be treated thoroughly to prevent urinary tract obstruction.

　　For patients with urinary tract stones, the following measures should be taken for prevention:

　　1. Review once every half year, increase exercise, and those who have been lying in bed for a long time should turn over frequently.

　　2. Drink plenty of water: If the urine volume of patients with urinary stones is increased by 50%, the incidence of urinary stones will decrease by 86%, especially before going to bed, more water should be drunk to develop the habit of drinking water and keep the daily urine volume not less than 2000-2500ml.

　　3. Adjust diet: Patients with calcium oxalate stones should eat less spinach, reed, tofu, chocolate, and other foods rich in oxalate or calcium; patients with calcium urate stones should avoid eating meat, crabs, spinach, animal viscera, and other foods.

　　4. Actively treat various infectious diseases.

　　5. It is not advisable to take sulfonamides and acetazolamide for a long time, which are easy to cause urinary crystallization.

　　The examination of urinary tract obstruction includes urine examination, cystoscopy, urography, ultrasound examination, CT examination, and other specific examination methods are described as follows.

　　1. Urine examination:When there is concomitant infection, there may be white blood cells and pus cells in the urine, and non-specific bacterial growth can be found in the middle urine culture. When there are concomitant stones, there may be red blood cells in the urine.

　　2. Cystoscopy:When there is lower urinary tract obstruction, cystoscopy can detect prostatic hyperplasia, bladder neck stenosis, bladder stones, small renal papillae and small chambers in the bladder, diverticula, and other lesions.

　　3. Urography:When there are concomitant stones, the shadow of non-transparent stones can be shown on the plain film. When there is upper urinary tract obstruction, there is often hydronephrosis on the affected side. Severe hydronephrosis often leads to renal function impairment and does not show up. Ureteral hydronephrosis can show expansion and tortuosity. When there is lower urinary tract obstruction, the bladder contour is irregular, and when there are diverticula, the size and location of the diverticula can be shown. Cystourethrography can show urethral stricture and valve lesions.

　　4. Ultrasound examination:When there is upper urinary tract obstruction, the affected kidney often shows a liquid level segment, indicating hydronephrosis of the affected kidney. When there are concomitant stones, the stones and their acoustic shadows can be detected. When there is lower urinary tract obstruction, varying degrees of residual urine can be measured in the bladder.

　　5. CT examination:When there is upper urinary tract obstruction, CT scan can not only measure the hydronephrosis of the affected kidney but also determine the thickness of the renal cortex, which is of great reference value for determining the treatment plan. CT scan can also detect stone shadows, and sometimes it can also be found that there are renal pelvis and ureteral tumors.

　　6. Renal function examination:In the early stage of obstruction, renal function is usually unchanged. Unilateral upper urinary tract obstruction often leads to renal function impairment on the affected side, which can be indicated by indocyanine green test, renal scan, and intravenous urography. Long-term obstruction of both upper urinary tracts and lower urinary tract strictures can lead to renal insufficiency in both kidneys, with increased blood urea nitrogen and creatinine levels, and the renal scan can show renal function impairment or obstructive renal scan.

　　7. Urodynamic examination:The maximum urine flow rate is reduced (≤10ml/sec) during lower urinary tract obstruction, and the intravesical pressure during micturition is significantly increased (＞70cm water column).

　　Patients with urinary tract obstruction caused by calcium oxalate stones should eat less vegetables such as spinach, reed, tofu, and chocolate that contain a lot of oxalate or calcium. Patients with uric acid calcium stones should avoid eating meat crabs, spinach, animal internal organs (such as liver, brain, kidney), and other foods. The patient's diet should be light, and it is best to eat easily digestible and absorbable foods such as vegetable congee and noodle soup.

　　There are many causes of urinary tract obstruction, and the treatment methods are complex. Therefore, detailed examination, comprehensive consideration, and the selection of a treatment plan based on this are necessary.

　　1. Treatment of the cause:The treatment of urinary tract obstruction diseases should be based on clear diagnosis and identification of the cause, eliminating the cause of urinary tract obstruction to achieve complete cure. For patients with stenosis at the renal pelvis and ureteral junction, if the affected kidney still has function, a pyeloplasty should be performed, which involves resecting the stenotic portion, resecting most of the enlarged renal pelvis, and then reattaching the renal pelvis and ureter. Kidney and ureteral stones can be treated with extracorporeal shock wave lithotripsy or surgical stone removal. Prostatic hyperplasia should be treated with transurethral resection of the prostate if the condition permits. Stricture of the urethra should be treated with resection and anastomosis or intubation. The treatment principle for bilateral urinary tract obstruction is that when both renal functions are still good, surgery should first be performed on the side with poorer renal function to ensure that both renal functions can fully recover; if both renal functions are poor, surgery should be performed on the side with better renal function first, and the other side should also be operated on as soon as possible.

　　2. Stenting above obstruction:If the cause of obstruction cannot be temporarily relieved, or the patient's condition does not allow for major surgery, a stenting procedure can be performed above the site of obstruction to promote urine drainage, allowing the damage caused by obstruction to gradually recover. When conditions permit, the cause of obstruction can then be removed. Nephrostomy is performed for upper urinary tract obstruction. Cystostomy is performed for lower urinary tract obstruction.

　　3. Nephrectomy:If the contralateral kidney is normal, the affected kidney can be removed when there is severe renal积水 due to upper urinary tract obstruction, the renal function is extremely damaged, or there is a severe infection, such as when the renal function is extremely damaged or there is a severe infection.