Obstructive uropathy is a blockage of the normal flow of urine somewhere along the urinary tract.
What is going on in the body?
The urinary tract consists of the kidneys, the ureters (tubes connecting the kidneys to the bladder), the bladder, and the urethra, the tube through which a person empties the bladder during urination. Obstruction can occur anywhere along this tract. Obstruction of urine flow increases the pressure to the kidney and can result in acute renal failure.
What are the causes and risks of the condition?
Obstructive uropathy may be caused by:
- kidney stones
- urethral strictures, or narrowing of the urethra
- pressure from nearby tumors
- scarring from previous radiation therapy
- urinary tract infection
- neuromuscular disorders, such as diabetic neuropathy
Obstructive uropathy is more common in a person with:
- sickle cell anemia
- diabetes mellitus
- neuromuscular disease
- benign prostatic hyperplasia (BPH)
- history of kidney stones
- history of radiation therapy
- uterine prolapse
- certain congenital disorders that affect the urinary tract
How is the condition diagnosed?
The history, a physical exam, and lab tests help in diagnosing the condition. X-rays may be taken to look for kidney stones. Ultrasound may show swelling of the kidneys and enlargement of the renal collection system, called hydronephrosis. If the obstruction is lower, it may show enlargement of the ureters, called hydroureter.
If the ultrasound does not show an obstruction, an intravenous pyelogram may be done. This test shows how the urine flows throughout the urinary tract. A contrast agent is injected into a blood vessel and is quickly excreted into the urine. Multiple x-rays are taken to show the flow of urine from the kidneys to the bladder. An obstruction shows up as a blockage of this flow. Retrograde pyelograms are similar. They show the flow of urine from the kidney to the urethra.
What are the treatments for the condition?
Treatment focuses on relieving the obstruction with surgery, bypass, or medications.
If the cause is benign prostatic hyperplasia, that condition is treated. BPH can be treated with medications, intermittent or continuous use of a urinary catheter in the bladder, or prostate surgery.
If the obstruction is at a higher level, two kinds of tubes can be used to bypass it. A catheter can be placed in the bladder, or a tube is placed through the skin close to the obstructed ureter. Other surgical procedures include redirecting the ureters or placing stents in them.
What are the side effects of the treatments?
Any urinary catheterization increases the risk of urinary tract infections. Surgery can be complicated by infection, bleeding, or reactions to the anesthesia.
What happens after treatment for the condition?
Recovery of kidney function often depends on how long the obstruction lasts. If it is less than 7 days, recovery is usually complete. If it is less than 2 weeks, the chance of renal recovery is about 70%. Obstruction that lasts up to 30 days has only a 30% chance of renal recovery. After 2 to 3 months of obstruction, renal recovery is unlikely. Some people continue to have kidney problems for a long period of time after obstruction.
How is the condition monitored?
The individual needs to make periodic visits to the healthcare provider to monitor kidney function. Any new or worsening symptoms should be reported.