Definition

Urinary tract obstruction, or obstructive uropathy, refers to a blockage that hinders the flow of urine along the urinary tract, which includes the kidneys, ureters, bladder, and urethra. Normally, urine should flow from the kidneys to the bladder, but if there is an obstruction, urine may backflow into the kidney, a condition known as reflux.

The ureter carries urine from the kidney to the bladder and consists of two tubes. Obstructive uropathy can cause swelling and damage to one or both kidneys, as well as anatomical disorders and strictures (narrowing of the passage).

This condition can affect individuals of all ages, including males and females. Additionally, urinary tract obstruction can pose problems for the fetus during pregnancy.

Causes

The most common causes of obstructive uropathy vary depending on age:

• In children, structural abnormalities such as valves at the back of the urethra and narrowing of the ureter or urethra are often observed.
• In young adults, kidney stones, ureteral stones, or other obstructions along the urinary tract are prevalent.
• In older adults, benign prostatic hyperplasia (enlargement of the prostate), prostate cancer, tumors, and urinary tract stones are common causes.

Less common causes of obstructive uropathy include:

• Ureteral polyps (tissue growth)
• Blood clots in the ureter
• Tumors inside or near the ureter
• Muscle or nerve abnormalities in the ureter or bladder, which can result from certain medications, congenital abnormalities, or spinal cord injuries
• Formation of scar tissue inside or around the ureter due to surgery, radiation therapy, or medications
• Protrusion at the bottom or end of the ureter into the bladder (ureterocele)
• Tumors, abscesses, and cysts (fluid-filled lumps) in the bladder, cervix, uterus, prostate, or other pelvic organs
• Large stool buildup in the rectum

During pregnancy, hydronephrosis or swelling in both kidneys may occur due to the enlarging uterus pressing on the ureters. This condition, known as pregnancy-related hydronephrosis, typically resolves on its own after pregnancy, although parts of the kidney and ureter may remain swollen afterward.

Risk factor

Several factors can increase a person's risk of developing obstructive uropathy:

• Men over 60 years of age are more likely to be affected because as men age, the prostate gland tends to enlarge.
• Pregnancy

Symptoms

The onset of obstructive uropathy can vary, manifesting as either rapid and acute or slow and progressive. Pain in the lower back, experienced on one or both sides of the body, is a common symptom. The intensity and location of pain can differ from person to person, depending on the organs affected.

Fever, nausea, and vomiting are frequently observed symptoms of obstructive uropathy. Swelling or discomfort in the lower back (kidney area) may occur as urine backs up into the kidneys.

Changes in urinary habits may indicate ureteral blockage. Symptoms can include:

• Difficulty urinating (dysuria)
• Reduced urine flow
• Increased frequency of urination, particularly at night
• Sensation of incomplete bladder emptying after urination
• Decreased urine output
• Presence of blood in the urine

Obstructive uropathy can also affect fetuses in utero. A lower-than-normal amount of amniotic fluid is one indicator of fetal obstruction. Since urine contributes to amniotic fluid, decreased urine output in a fetus with obstructive uropathy can lead to reduced amniotic fluid volume. This condition may result in complications for the fetus or during delivery.

Diagnosis

To establish a diagnosis of obstructive uropathy, a doctor will conduct a comprehensive assessment consisting of a medical interview, physical examination, and diagnostic tests. During the medical interview, the doctor will inquire about the symptoms experienced, including their onset, any medications taken, and the patient's medical history.

Following the medical interview, a physical examination will aid in diagnosis. If necessary, the doctor will proceed with diagnostic tests such as:

• Urine Test: This examination can detect the presence of blood or signs of infection in the urine.
• Blood Test: Abnormal levels of urea and creatinine in the blood may indicate kidney dysfunction. An increased number of white blood cells may suggest infection, while a decreased red blood cell count may indicate kidney dysfunction.
• Imaging Examinations: Various imaging techniques, including ultrasound (USG), CT scan, MRI, and voiding cystourethrography (VCUG), may be used to identify evidence of obstruction, such as hydronephrosis, or to locate the blockage itself.
• Cystoscopy: This procedure involves the insertion of a camera-equipped instrument into the bladder and urethra to visualize any abnormalities.

Management

The primary goal of therapy for obstructive uropathy is to address the underlying cause of the obstruction. For instance, if the urethra is obstructed due to prostate enlargement, therapy may involve medications, surgical intervention, or urethral dilation with instruments. In cases where urinary flow is blocked by stones in the ureter or kidney, therapies such as lithotripsy or endoscopic surgery may be necessary to remove the stones.

If the cause of obstruction cannot be promptly addressed, especially in the presence of infection, kidney failure, or severe pain, urinary drainage may be required. In instances where hydronephrosis is caused by a challenging obstruction, urine accumulated above the site of blockage can be drained either through a tube inserted into the back of the kidney or via a soft plastic tube connecting the bladder to the kidney (ureteral stent).

Complications associated with these procedures may include tube displacement, infection, and discomfort. In cases where immediate attention is needed for urethral obstruction, a soft rubber catheter may be inserted into the bladder to facilitate urine drainage.

Complications

Obstruction can typically be treated, but if left unattended for too long, it can lead to several complications, such as:

• Kidney failure
• Infection
• Increased likelihood of stone formation

Prevention

While complete prevention of urinary tract obstruction may not be possible, there are steps you can take to reduce the risk:

• Change urination habits: Urinate when you feel the urge to do so. Holding in urine frequently can strain the bladder muscles and increase the risk of urinary tract infections.
• Take prescribed medication: If you have prostate issues like benign prostatic hyperplasia (BPH), adhere to your doctor's prescribed medications. Avoid medications that can disrupt urine flow, such as certain cold medications and nonsteroidal anti-inflammatory drugs (NSAIDs).
• Perform pelvic floor muscle exercises: Strengthening the pelvic floor muscles through exercises like Kegels can improve bladder and bowel function, reducing the risk of obstruction.
• Modify diet and lifestyle: Prevent urinary obstruction due to constipation by adopting a healthy diet and lifestyle. Consume adequate fiber, stay hydrated by drinking enough water, and engage in regular physical activity.

When to see a doctor?

If you experience symptoms of urinary obstruction, promptly consult your doctor. Additionally, if you are unable to urinate at all or experience severe pain in the lower back or lower abdomen, seek medical attention immediately.

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