Hydroureter is a medical condition characterized by an enlargement of one or both ureters, the tubes that transport urine from the kidneys to the bladder. This dilation occurs due to a backup of urine within the urinary system.
What is Hydroureter
The urinary system filters waste from the blood and expels it as urine. This system includes two kidneys, which produce urine, and two ureters, muscular tubes connecting each kidney to the bladder. The bladder stores urine until it is expelled through the urethra. Normally, urine flows from the kidneys, down the ureters through rhythmic muscular contractions (peristalsis), and into the bladder.
In hydroureter, this normal flow is disrupted, causing urine to accumulate and stretch the ureter, leading to its dilation. While hydroureter refers specifically to ureter swelling, it often co-occurs with hydronephrosis, the distension of the kidney’s urine-collecting part (renal calyces and pelvis). Both conditions result from impaired urine outflow, but hydroureter focuses on the ureteral component of this obstruction or functional issue.
Causes and Contributing Factors
Hydroureter can result from various factors that impede normal urine flow. Physical obstructions within the urinary tract are a common cause. Kidney stones can become lodged in the ureter, blocking urine passage. Tumors in or near the urinary tract, such as those in the bladder, prostate, or uterus, can exert pressure on the ureters, preventing drainage. In older men, benign prostatic hyperplasia (BPH), an enlargement of the prostate gland, can compress the urethra, leading to urine backup.
Other obstructive causes include strictures, narrowings of the ureter often resulting from injury, infection, or prior surgery, and blood clots. Congenital abnormalities also contribute, particularly in infants and children. These include structural issues like urethral valves, ureterovesical junction obstruction, or ureteropelvic junction obstruction at the ureter-kidney junction. Functional issues can also disrupt urine flow, such as vesicoureteral reflux, where urine flows backward from the bladder into the ureters and kidneys. Neurogenic bladder, affecting nerve control, can impair proper emptying. Pregnancy is a physiological cause, affecting many pregnant women due to the enlarging uterus compressing the ureters and hormonal effects.
Recognizing the Signs
Hydroureter can cause a range of symptoms, though severity varies, and it may be asymptomatic in early stages. Pain is a common indicator, often described as a dull, constant ache or sudden, intense discomfort. This pain typically localizes in the lower back, side, or abdomen and can sometimes radiate to the groin area.
Changes in urination patterns are common. These include increased urinary frequency, a strong urge to urinate, or incomplete bladder emptying. Some individuals may experience painful urination (dysuria) or notice blood in their urine (hematuria). Digestive disturbances, such as nausea and vomiting, can also accompany the condition. If an infection develops due to trapped urine, symptoms like fever, chills, and a general feeling of illness may occur.
Diagnosis and Treatment Approaches
Diagnosis involves medical evaluation and specialized tests. A healthcare provider begins with a physical examination, inquiring about symptoms and medical history, and checking for tenderness or swelling in the kidney and bladder areas. Urine tests detect signs of infection, blood, or crystals indicating kidney stones. Blood tests, including a complete blood count (CBC) for infection and kidney function markers like blood urea nitrogen (BUN) and creatinine, assess overall kidney health.
Imaging procedures are key to confirming diagnosis and identifying the underlying cause. Ultrasound is often the initial imaging choice, as it visualizes the kidneys, ureters, and bladder without radiation. Computed tomography (CT) scans or magnetic resonance imaging (MRI) may provide more detailed views of the urinary tract and surrounding structures. A CT urogram, using a special dye, offers comprehensive images. For assessing kidney function and drainage, a MAG3 scan may be used.
Treatment for hydroureter is tailored to its cause and symptom severity. In mild cases, especially without obstruction or in pregnant individuals, watchful waiting may be an option as the condition can resolve on its own. Medications can manage pain or treat urinary tract infections with antibiotics. When an obstruction is present, various procedures restore urine flow.
A urinary catheter may drain urine from the bladder, especially for lower urinary tract obstruction. For blockages within the ureter, a ureteral stent can be inserted to hold the ureter open, allowing urine to pass. If stenting is not feasible, a percutaneous nephrostomy tube can drain urine directly from the kidney. Kidney stones causing obstruction may be treated with extracorporeal shockwave lithotripsy (ESWL), which uses shock waves to break stones, or ureteroscopy, where a thin scope removes or breaks up stones. More complex cases, such as tumors, severe strictures, or anatomical abnormalities, may require surgical intervention to remove the obstruction or correct the structural issue.
Potential Complications
Untreated or delayed hydroureter treatment can lead to serious health complications. Persistent urine backup within the ureter exerts increased pressure on the urinary system. This elevated pressure can extend to the kidney itself, causing hydronephrosis, swelling and damage to the kidney’s urine-collecting structures.
A common complication is urinary tract infections (UTIs), as stagnant urine provides a breeding ground for bacteria, increasing infection risk. If these infections ascend to the kidneys, they can lead to pyelonephritis, a severe kidney infection that can cause damage. Prolonged, severe hydroureter, especially with significant hydronephrosis, can result in kidney damage, including scarring and loss of functional capacity. In advanced stages, this can progress to chronic kidney disease or kidney failure, necessitating treatments like dialysis or kidney transplantation. Prompt diagnosis and appropriate treatment are important to prevent irreversible outcomes and preserve kidney function.