Ureteral Stricture

Description

The ureters are hollow muscular tubes that transport urine from the kidneys to the urinary bladder. A ureteral stricture is an abnormal narrowing of one or both ureters that obstructs the normal flow of urine.

The exact prevalence of ureteral stricture is unknown. It occurs more frequently in men.

Cause

Ureteral stricture may be congenital or acquired. The exact cause of congenital ureteral stricture is not fully understood. Acquired strictures most commonly develop following urinary tract inflammation, postoperative scar formation, or ureteral trauma. The distal ureter is the most frequently affected segment.

Risk Factors

Risk factors for ureteral stricture include:

• Recurrent urinary tract infections.
• Previous urological instrumentation or surgical procedures.
• Ureteral trauma.

Symptoms

A ureteral stricture impairs the passage of urine into the urinary bladder. Initially, increased ureteral peristalsis helps propel urine past the narrowed segment. Over time, the ureter proximal to the stricture becomes dilated and tortuous. The rate of disease progression depends on the severity of the narrowing—the more severe the stricture, the greater the obstruction and the more rapidly normal ureteral function deteriorates.

Common symptoms include:

• Flank or abdominal pain.
• Nausea and vomiting.
• Recurrent urinary tract infections.
• General weakness.

Diagnosis

Because ureteral stricture has numerous possible causes, a thorough medical history and clinical evaluation are essential. Diagnostic investigations may include plain radiography, retrograde pyelography, ultrasonography, ureteroscopy, or, less commonly, magnetic resonance imaging (MRI). If malignancy is suspected as the cause of the stricture, tissue biopsy may be required.

Treatment

Treatment is usually minimally invasive and aims to restore normal urine flow. Endoscopic or laparoscopic procedures are commonly performed to excise or incise the scar tissue causing the stricture. If a long segment of the ureter is affected, ureteral reconstruction using a segment of the small intestine may be required, although this is rarely performed. Balloon dilatation is another treatment option. Following dilation, a temporary ureteral stent is commonly placed for several weeks to maintain ureteral patency.

Source | Author Doctor Nikas Samuolis, reviewed by Prof. Virginijus Šapoka | Vilnius University | Faculty of Medicine | Head of the Department of Internal Medicine, Family Medicine, and Oncology