Obstructive uropathy is a syndrome that occurs when there is a violation of the outflow of urine in any part of the urinary tract. The cause of the disease are congenital anomalies of the urinary tract, urolithiasis, volumetric neoplasms of the pelvic organs and functional disorders. Uropathy is manifested by non-localized abdominal pain, difficulty or delay in urination. To diagnose the disease, CT and MRI of the abdominal organs, intravenous urography, cystourethrography, blood and urine tests are prescribed. Treatment involves surgical removal of obstruction and an individual course of drug therapy.
ICD 10
N13 Obstructive uropathy and reflux uropathy
Meaning
Obstructive uropathy occurs with a frequency of 1:2000 of the population, while up to 11% of patients with chronic renal failure have such a concomitant diagnosis. In the diagnosis of the disease, two peaks are noted: the childhood period, when disorders are associated with congenital anomalies, and the age over 60 years, which is characterized by various organic diseases of the urinary organs. In all age groups, men get sick more often than women. Given the severity of the course and the high risk of complications, obstructive uropathy is a significant problem of modern urology.
Causes
Obstruction occurs in any part of the urinary system – from the renal tubules to the external opening of the urethra. Congenital uropathy, characteristic of childhood, is associated with anatomical defects: valves of the posterior urethra, stenosis of the ureteral-vesicular joint, obstructive megaureter. Acquired disorders are caused by the following groups of reasons:
- Mechanical obstruction. Blockage of the urinary tract lumen is most often associated with urolithiasis. The cause of obstructive disorders may be ureteral polyps, urothelial carcinoma, uric acid crystals in the renal tubules.
- Functional urological diseases. Urinary pathologies develop with neurogenic bladder and dysfunction of the neck of the organ. Drug-induced dysfunctional uropathy is observed when taking anticholinergic drugs.
- Prostate diseases. Benign prostatic hyperplasia (prostate adenoma) is the most common cause of obstructive uropathy in older men. Less often, urinary disorders occur due to abscessing prostatitis, prostate cancer.
- Gynecological diseases. The delay in the outflow of urine in women is often caused by compression syndrome. The urinary tract is compressed with tubovarial abscess, Gartner’s canal cyst, cervical and ovarian cancer.
Rare reasons. Compression of the urinary tract is provoked by diseases of the gastrointestinal tract (appendicitis, Crohn’s disease, diverticulum), retroperitoneal space (lymphoma, sarcoidosis, metastatic tumors). Compression can be caused by dilated blood vessels in aneurysm, thrombophlebitis of the ovarian vein.
Pathogenesis
With obstructive uropathy, several pathological processes occur that complement and aggravate each other’s action. At first, there is an increase in pressure in the ureters, which is compensated for by the extensibility of the urinary tract for 2-3 days. Then the accumulation of urine causes dilation of the collecting tubules and distal tubules in the kidneys. This process eventually leads to tubular atrophy and damage to the glomerular apparatus of the kidneys.
At the same time, intrarenal blood flow decreases and there is a redistribution of venous outflow. Increasing renal ischemia activates the renin-angiotensin system, which produces vasoconstrictor substances. In conditions of hemodynamic disorders, the production of proinflammatory cytokines increases. The interstitial space is infiltrated by macrophages and lymphocytes, and the renal parenchyma is remodeled.
Symptoms
The main clinical manifestation of the disease is called pain syndrome, which occurs with any severity of obstruction. The pain is associated with overextension of the bladder and ureters. They do not have a clear localization, they can radiate into the lower back, scrotum in men and labia in women. The symptoms are similar to the manifestations of diseases of the gastrointestinal tract and genitals, which often causes diagnostic errors.
With a bilateral lesion, the main clinical sign is urinary retention. Partial obstruction of the ureters is accompanied by a weakening of the jet, the need to strain hard for emptying the bladder. With complete blockage of the urinary tract, patients develop anuria. Unilateral lesions with both functioning kidneys do not cause significant dysuric disorders.
The nonspecific symptoms of obstructive uropathy are represented by weakness, increased fatigue, nausea and lack of appetite. In case of bacterial infection, fever and increased dysuric phenomena are possible. Since renal pathology is often complicated by secondary arterial hypertension, patients complain of headaches, palpitations, and discomfort in the heart area.
Complications
In the absence of treatment of uropathy, obstructive nephropathy develops, which is pathomorphologically represented by tubulointerstitial nephritis. If the process develops in both kidneys, the functions of blood filtration and urine formation are sharply reduced, therefore, patients develop renal failure. With unilateral uropathy, the risk of critical renal dysfunction is not excluded, since reactive vascular or ureteral spasm may occur in a healthy kidney.
Another dangerous consequence of the disease is urinary tract infections (UTIs). Most often they are caused by E. coli, klebsiella, staphylococci and streptococci. Lesions of the upper urinary tract are mainly represented by chronic recurrent pyelonephritis, inflammation of the lower urinary tract is manifested by cystitis and urethritis. Bacterial UTIs are occasionally complicated by paranephritis, kidney abscess, sepsis.
Diagnostics
Patients with complaints of urinary outflow difficulties and other urination disorders require the help of a urologist. The specialist collects complaints and anamnesis of the disease, conducts a physical examination with a check of Pasternatsky’s symptom. To find out the root cause of obstructive uropathy, an extended laboratory and instrumental examination is necessary:
- Abdominal ultrasound. The basic method that is used to diagnose hydronephrosis, obstruction at the level of the kidneys and ureters. The study is supplemented with Doppler ultrasonography to detect increased vascular resistance, an early marker of acute obstructive uropathy.
- CT with contrast. Computed tomography is the most informative method for diagnosing the level of obstruction, especially in urolithiasis. With the help of the study, it is possible to study the structure of the renal parenchyma and determine the complications of uropathy. If there is a contraindication to X-ray irradiation, the diagnosis is replaced by MRI.
- Intravenous urography. Diagnosis is carried out with insufficient informative CT, reveals urinary tract stones and blood clots that complicate the outflow of urine. As an alternative to intravenous contrast administration, retrograde pyelography is used, in which the contrast agent is injected through a cystoscope, bypassing the vascular bed.
- Cystourethrography. The study helps to determine obstructive disorders in the lower urinary tract. By the nature of the contrast agent promotion during urination, it is possible to diagnose vesicoureteral reflux, obstruction of the bladder neck, urethral stricture.
- Urine tests. All patients undergo a general analysis of urine to determine its density, transparency, composition of organic and inorganic sediment. The concentration function of the kidneys is analyzed according to the Zimnitsky method, if secondary infections are suspected, a Nechiporenko sample and a urine sample are performed.
- Blood test. In a clinical blood test, attention is paid to the level of leukocytes as a marker of UTI, the amount of hemoglobin and erythrocytes – anemia indicates chronic kidney disease. In biochemical analysis, doctors are particularly interested in the amount of urea and creatinine. Be sure to calculate the glomerular filtration rate (GFR).
Since obstructive uropathy has dozens of etiological factors, a urologist needs to conduct a large-scale differential diagnosis. When symptoms appear in childhood, it is mandatory to consult a pediatrician and a geneticist for congenital diseases and anomalies. Violation of urine flow in combination with weight loss and intoxication syndrome requires targeted oncological examination.
Treatment
Surgical treatment
The primary task of doctors is to eliminate obstacles to the outflow of urine and restore the work of the urinary system. To do this, minimally invasive and surgical techniques are used. With anuria and a sharp deterioration in the patient’s condition, intervention is carried out urgently, in parallel with the diagnosis, in other cases, a planned operation is indicated.
The method of surgical treatment depends on the etiological factor. With lower obstructive uropathy, the placement of a urinary catheter is indicated, which ensures constant and unhindered removal of fluid. With a high level of obstruction, an urostoma or nephrostoma is established, which persist until the root causes of the disease are eliminated. In case of urolithiasis, endoscopic removal of stones, percutaneous or ultrasound lithotripsy is necessary.
Pharmacotherapy
Drug treatment is selected differentially, taking into account the degree of impaired renal function and the presence of signs of infectious complications. In the presence of UTIS, courses of antibacterial therapy are prescribed. After restoring the patency of the urinary tract, diuretics are prescribed to eliminate oliguria. Symptomatic correction of intoxication, anemia and other syndromes associated with renal pathology is carried out.
Prognosis and prevention
Renal pathology in uropathy is reversible, therefore, with timely restoration of the urinary process, patients fully recover. The prognosis worsens with untreated urinary tract infection and chronic kidney disorders that persist despite ongoing therapy. Prevention consists in the prevention of diseases that can cause obstruction.