Retrograde Pyelogram is a urologic procedure where a contrast dye is injected into the kidneys through the ureters in order to visualize the bladder, ureters and renal pelvis. It is used to determine whether the obstruction in the ureters or kidney is due to a tumour, stone, blood clot or stricture (narrowing). It is also used to evaluate placement of catheters or ureteral stents. It is usually performed when an intravenous pyelogram (IVP) is not able to provide a definitive diagnosis. It is also performed in patients with chronic kidney disease and who are allergic to the dye used with IVP. Patients who are pregnant or suspect they may be pregnant should not have a retrograde pyelogram as radiation exposure may lead to birth defects.
During IVP, the dye is injected through a vein in the arm before the X-ray is taken. In retrograde pyelogram, the contrast dye is injected directly into the ureters and kidney via a catheter and then X-rays are taken. The advantage of retrograde pyelogram over IVP is that it can be performed on patients who are allergic to contrast dye as only a minimal amount of dye is absorbed by the body.
Retrograde pyelogram is performed under local or regional anaesthesia. A thin lighted viewing tool called a cystoscope is inserted through the urethral opening and advanced into the bladder. The bladder is examined, and a catheter is inserted through the cystoscope into one or both ureters. Through the catheter, the contrast dye is injected into the ureter and a series of X- rays are taken at timed intervals. The catheter and cystoscope are removed after the procedure.
Risks and complications
Some of the possible complications associated with retrograde pyelogram include, urinary tract infection, perforation of the bladder, infection, bleeding, nausea and vomiting.