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Urethrogram 1181

Urethrogram
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• Sterile lubricating jelly
Difficulty level: ♦♦
or termination of the procedure.
• Sterile syringe for contrast (e.g., 12 mL) should prompt adjustment of the catheter
Overview and Goals • Sterile syringe for inflating the catheter • Mild, transient submucosal hemorrhage
• The urethra cannot be seen on survey radio- balloon secondary to balloon: avoid leaving urethral
graphs, and a positive-contrast examination • Sterile catheter adapter (Christmas-tree type) catheter in place longer than 15 minutes
is necessary for radiographic evaluation. • Sterile 3-way stopcock (urethral trauma caused by local ischemia
• Ultrasound can be used for visualizing small • Sterile saline and mechanical trauma)
portions of the urethra in the male; however, • Sterile gloves • Urinary bladder–associated complications
adequate diagnostic imaging of the entire • Enema bag/set (hemorrhagic cystitis, catheter kinking or
urethra requires radiographic assessment • Open-ended tomcat catheter (e.g., 3.5 Fr) knotting in the bladder lumen, pulmonary
with the injection of iodinated contrast used for male cats air embolism, bladder rupture secondary Procedures and Techniques
material. to overdistention of the bladder) are rare
• A simple urethrogram is quick and easy to Anticipated Time because the catheter remains in distal
perform. Approximately 20-30 minutes urethra.
• A vaginocystourethrogram is usually per- • Bacterial contamination
formed in the female because of the difficulty Preparation: Important • False results: catheter in too far (past lesion
of catheterizing the female urethra. Checkpoints site), too little contrast, air bubbles
• An enema (p. 1099) is indicated approxi- • Contrast media reactions (absorbed systemi-
Indications mately 2 hours before the study to ensure cally though mucosa)
• Clinical signs the removal of fecal material from the colon • Anaphylactic reactions (rare)
○ Dysuria, stranguria (could compromise visualization of the
○ Difficulty catheterizing, urethral obstruction urethra). Procedure
○ Trauma to pelvis or os penis • Dilute iodinated contrast media to 50% • Preliminary caudal abdominal radiographs
○ Hematuria in a voided or catheterized solution with sterile saline. (lateral and oblique ventrodorsal) are made
urine sample but normal urine on • Sterile gloves should be worn from this point to set radiographic technique and ensure
cystocentesis forward in the preparation. adequate preparation of the animal.
○ Hemorrhagic preputial discharge with a • Draw 12 mL of diluted contrast material • The kilovoltage peak (kVp) should be
normal penile/preputial physical exam into 12-mL syringe. set between 65 and 75 to maximize
• Differential diagnosis • Remove Foley catheter from packaging in a contrast.
○ Urethral calculi (especially important with sterile manner, and remove guide wire. • The dog should be placed in left lateral
radiolucent calculi) • Attach catheter adapter (Christmas tree) to recumbency (to reduce the risk of pulmonary
○ Urethral tear/rupture, stricture, neoplasia, the open port (lumen) of the Foley catheter. air embolism).
or fistula (p. 1009) • Attach 3-way stopcock to catheter adapter. • An assistant should then extrude the penis
○ Iatrogenic urethral trauma • Load syringe with air for inflating balloon from the prepuce.
○ Other urethral mucosal abnormalities later by drawing appropriate amount of air • The penis should be prepped with a mild
○ Penile or extrapelvic urethral disease into the syringe (based on recommendation surgical scrub solution.
○ Congenital anomalies of Foley balloon size). • Sterile lubricating jelly is placed onto the
○ Postoperative evaluation of urethra to • Test integrity of the balloon. tip of the Foley catheter.
assess patency and completeness of ○ Attach syringe containing air to side port • Insert Foley catheter into the distal urethra
healing (going to balloon, not the catheter lumen). until the balloon can no longer be seen, but
○ Evaluation of perineal or caudal abdominal ○ Infuse air into the balloon, filling it to no further. The procedure is conducted with
masses the recommended level to ensure balloon the catheter inserted into the urethra a very
is intact, and hold for a few seconds (to short distance to avoid passing beyond the
Contraindications test inflation). site of the lesion.
Relative contraindications include active lower ○ After it is clear the balloon will hold air, • Inject air into balloon to inflate and then
urinary infection, emphysematous cystitis, or withdraw the air from the balloon back close the stopcock to maintain inflation.
allergy to radiopaque contrast. into the syringe. A suitable volume of air should meet little
• Attach syringe with contrast material onto resistance and yet should provide enough of
Equipment, Anesthesia 3-way stopcock, and fill the Foley catheter a seal to prevent backflow of contrast out
• Heavy sedation is often adequate to perform with contrast material. If this step is bypassed, the urethra during injection.
the study in male dogs; general anesthesia air bubbles will be injected, resulting in a • Tug very lightly on the catheter to ensure
can be used if necessary. The male cat should suboptimal study. the balloon seal is tight, and adjust inflation
be under general anesthesia. • Close the stopcock to the contrast material. (increase or decrease) accordingly.
• Mild surgical scrub solution and gauze/ • In male cats, diluted contrast material is • With the dog’s hindlimbs pulled forward to
sponges for disinfecting the penis before drawn into the syringe, and the syringe is allow an unobstructed radiographic projec-
catheterization attached directly to the tomcat catheter. tion of the urethra, inject 12 mL of contrast
• Urinary catheter (preferably with inflatable material rapidly into the urethral catheter.
balloon), such as a Foley catheter Possible Complications and NOTE: The contrast material should flow
• Iodinated contrast medium (sodium iothala- Common Errors to Avoid smoothly and with no resistance; if resistance
mate, sodium diatrizoate) or low-osmolar, • Trauma due to overdistention of the balloon is met, stop the injection, and make the
nonionic, water-soluble iodines such as • Rupture of the urethra: forceful injection radiographic exposure.
iohexol or iopamidol (180-300 mg iodine/ when the urethra is obstructed can lead to • Make radiographic exposure just before the
mL most common) can be used. urethral rupture. Resistance to injection end of injection.

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