Retrograde pyelography combines the use of a long, flexible viewing tube called a cystoscope with contrast x-rays to visualize the kidneys and ureters. The cystoscope is inserted through the urethra into the bladder; fiberoptic cables permit direct visual inspection of these structures. A catheter is then threaded through the scope so that a contrast dye can be infused directly into the ureters to delineate them on x-ray films. Retrograde pyelography is most often performed when intravenous pyelography produces inconclusive results, or when it cannot be performed because of impaired kidney function or another reason.
Purpose of the Retrograde Pyelography
- To evaluate the structure and integrity of the kidneys and ureters
- To identify the cause of obstructions in the kidneys or ureters, such as tumors, narrowing, scarring, blood clots, or stones
- To determine if a catheter or ureteral stent is positioned properly
Who Performs It
- A urologist or a radiology technician.
- Pregnant women should not undergo this test because exposure to ionizing radiation may harm the fetus.
- Retrograde pyelography is the preferred test to examine the urinary tract in people who are allergic to iodine or shellfish, and therefore may be hypersensitive to iodine-based contrast dyes. Allergic reactions rarely occur with this test, because none of the dye is absorbed into the bloodstream.
- This test must be performed carefully to prevent further damage to the ureter in individuals who have a slowing or stoppage of normal urine flow (urinary stasis) caused by ureteral obstruction.
- The presence of feces, gas, or residual barium from recent contrast x-rays of the gastrointestinal system can obscure visualization of the urinary tract.
Before the Retrograde Pyelography
- Be sure to tell your doctor if you have a known shellfish or iodine allergy or have ever had an adverse reaction to x-ray contrast dyes.
- Tell your doctor if you are or could be pregnant.
- Notify your physician if you are sensitive to or are allergic to any medications, latex, and tape.
- Notify your physician of all medications and supplements that you are taking. In particular, be sure to mention if you are taking blood thinners, including aspirin, or any other drugs that affect blood clotting. You may have to stop them for a short period before the test.
- Tell your doctor if you have/have ever had a bleeding disorder.
- If you are receiving a local anesthetic, you should have a liquid breakfast on the morning of the test.
- If general anesthesia is required, do not eat or drink after midnight on the day before the test.
- An intravenous (IV) catheter may be inserted into a vein in your arm to provide fluids and/or to administer a general anesthetic during the procedure.
What You Experience
- You will lie on your back on an examination table with your knees bent and feet resting in stirrups.
- After local or general anesthesia has been administered, the doctor carefully inserts the cystoscope through your urethra and into the bladder, and performs a visual examination.
- Next, a thin tube, or catheter, is threaded through the cystoscope into the ureter. (Sometimes both ureters are catheterized.)
- The contrast dye is injected through the catheter. If you are conscious, you may feel some discomfort during catheter insertion and when the dye is instilled.
- X-ray films are obtained. You must remain still to avoid blurring the pictures.
- As the catheter is slowly withdrawn, more contrast dye is instilled and additional x-rays are taken to visualize the complete length of the ureter.
- A delayed x-ray film is usually taken about 5 minutes after the last injection to check for retention of contrast dye, which indicates a ureteral obstruction.
- If an obstruction is present, a catheter may be left in place in the ureter so that it can drain.
- The procedure usually takes about 1 hour.
Risks and Complications
- Possible complications include urinary tract infection, temporary blockage of the ureter due to swelling, and, rarely, inadvertent perforation of the bladder or ureter.
- Rarely, some people may experience an allergic reaction to the iodine-based contrast dye, which can cause symptoms such as nausea, sneezing, vomiting, hives, and occasionally a life-threatening response called anaphylactic shock. Emergency medications and equipment are kept readily available.
After the Retrograde Pyelography
- If no complications develop, you are usually free to leave the testing facility. Your doctor will instruct you to keep track of your urine output and report any urinary retention.
- Your urine may contain blood at first, causing a slight pink tinge; this should resolve after you have voided 3 times. If blood persists or you see bright red blood or blood clots, notify your physician.
- Urination is often painful or difficult for the first few times after the test. You may be instructed to take tub baths to help ease any discomfort, and painkillers will be prescribed, as needed.
- You are encouraged to increase your intake of fluids to help prevent urinary retention and accumulation of bacteria in your bladder.
- Inform your doctor immediately if you experience pain in the area of the kidneys, chills, fever, redness, swelling, bleeding or increase in the amount of blood in your urine and difficulty urinating.
- The doctor will examine the x-ray films for evidence of any abnormalities, such as a ureteral obstruction.
- If a definitive diagnosis can be made, your doctor will recommend an appropriate course of treatment.
- In some cases, additional diagnostic tests, such as a renal CT scan, renal nuclear scan, or ureteroscopy, may be needed to further evaluate abnormal results.
The Johns Hopkins Consumer Guide to Medical Tests
Simeon Margolis, M.D., Ph.D., Medical Editor
Updated by Remedy Health Media