kidney and urinary tract disorders
Urinary Tract Obstruction
Diagnosis of Urinary Obstruction
Bladder catheterization Imaging Early diagnosis is important, because most cases of obstruction can be corrected and because a delay in treatment can lead to irreversible kidney damage. Doctors may suspect obstruction because of a person’s symptoms, such as renal colic, symptoms of bladder distention, or a decrease in the volume of urine. A distended kidney can rarely be felt in the flank, usually if the kidney is greatly enlarged in an infant or a child or a thin adult. A distended bladder can sometimes be felt in the lower part of the abdomen just above the pubic bone. Doctors depend on testing to make the diagnosis. Bladder catheterization (insertion of a hollow, soft tube through the urethra) is often the first diagnostic test done in people with symptoms that suggest the bladder is distended, such as pelvic pressure or distention. If the catheter drains a large amount of urine from the bladder, then either the bladder outlet or the urethra is obstructed. Many doctors do ultrasonography to determine whether the bladder is filled with a large amount of urine before doing bladder catheterization. Imaging tests can be done to identify evidence of obstruction, such as hydronephrosis or a site of blockage, when the presence or site of obstruction is in doubt. For example, Ultrasonography is a very useful test in most people (particularly children and pregnant women) because it is fairly accurate and does not expose the person to any radiation. However, ultrasonography is not always accurate in its ability to localize the site of obstruction. Computed tomography (CT) is an alternative. It is rapid and highly accurate, particularly at identifying stones. CT has traditionally involved exposure to significant doses of radiation. However, with newer CT scanners and new ways of using them, CT images can be obtained with much smaller doses of radiation. Other imaging tests, such as Cystography and cystourethrography (VCUG), may be done to identify the site of obstruction, most often in children who have obstruction of the bladder or urethra. This imaging test can identify blockages in those structures (for example, caused by birth defects). It can also identify when urine flows backward from the bladder into the ureters (called vesicoureteral reflux) and causes Endoscopy with a special rigid or flexible endoscope (a Cystoscopy ) can be used to examine the urethra, prostate, and bladder. A longer rigid or flexible endoscope (ureteroscope) can be passed into the ureters or kidneys to identify sites of obstruction. Sometimes the cystoscope, ureteroscope, or both can also be used to remove objects causing obstruction. Laboratory Tests for Blood Disorders and 