Radiography: vaginourethrography

• Allows visualization of vagina and urethra.

• Investigation of lower urinary tract disease:
  • Ectopic ureters Ureter: ectopic.
  • Dysuria.
  • Hematuria Hematuria.
• Investigation of vaginal discharge.
• Investigation of urinary incontinence Urinary incontinence.
• Investigation of physical vaginal abnormalities, eg neoplasia   stenosis.

Advantages

• Simple and quick to do.

Disadvantages

• Requires general anesthesia General anesthesia: overview.

• Vaginourethral endoscopy (requires specialized equipment not readily available in practice).

Preparation

• 15 min.

Procedure

• 10 min (plus time for general anesthesia).

Criteria for choosing test

• Is the examination appropriate?
• Can you make the diagnosis without it?
• Will your management of the case be affected by the outcome of the examination?

Risk assessment

• Procedure carries minimal risk above that of anesthesia.
• Reported increased risk of vaginal rupture in Shelties and Rough Collies.

Minimum equipment

• X-ray machine.
• Radiographic cassette.
• Processing facilities.
• Protective clothing (lead apron) for radiographer.
• Positioning aids (sandbags and ties).
• Method of labelling film.

Ideal equipment

• Ability to process films during procedure so that repeat radiographs can be taken during course of study if required.
• High output x-ray machine.
• High definition screen.
• Grid for examination of large dog.
• Tongue clamps or Allis tissue forceps.
• Vaginal speculum may be helpful for bladder catheterization in bitch.

Minimum consumables

• Radiographic film.
• Contrast agent.
• Syringe.
• Three way stopcock.
• Foley catheter.
  If patient is a very small dog, an angiographic, flow-directed balloon-catheter, eg Swan-Gante, may be used because of smaller gauge. (May have access to this type of catheter through a radiology department of a local human hospital.
  To prevent tip of catheter occluding urethral orifice cut tip off Foley catheter beyond bulb but ensure bulb of catheter still inflates

• Withhold food from animal for 12 hours prior to anesthesia.

• General anesthesia required.

Step 1 - Control films

• Check exposure settings and processing.
• Confirm positioning adequate (dogs should be positioned in lateral recumbency).
• Confirm diagnosis not apparent without contrast study.

Step 2 - Additional radiographic contrast studies - optional

• Catheterize bladder Urethral catheterization: female and perform pneumocystogram Radiography: double contrast cystography.
  Only distend bladder moderately to allow for further distension by contrast agent.
• Remove catheter after this procedure.

Step 3 - Instill positive contrast agent

• Prefill the Foley catheter and syringe with contrast media.
• Insert catheter into vestibule of vagina and inflate bulb of Foley catheter with water/saline.
• Apply tongue/Allis tissue forceps to vulval lips next to catheter to prevent reflux of contrast.
• Gently pull catheter caudally so that bulb of catheter is at entrance to vagina to avoid obstructing urethral orifice.
• Inject contrast up to 1 ml/kg. In larger dogs a contrast medium may be administered in sequential 10 ml aloquats until adequately distended.
  Stop injection if resistance felt or reflux of contrast from vagina.

Step 4 - Obtain radiographic views

• Make lateral radiographic Radiography: abdomen exposure at end of injection.

Step 1 - Assess radiographs

• Check radiograph to ensure adequate distension of vagina .

Step 2 - Additional radiographic procedures

• Repeat exposure after additional contrast added if necessary.

Step 3 - Remove catheter

• Remove clamps.
• Deflate catheter bulb.
• Withdraw Foley catheter.

Antimicrobial therapy

• Provided sterile technique used antibiotics are not required.

Potential complications

• Vaginal rupture has been reported as a consequence of vaginourethrography.
  Rough Collies and Shelties appear to be at greater risk of this complication.
• Conservative management should be sufficient if vaginal rupture occurs.
• A reduced dose may be required in incontinent bitches.
• Over-distension of bladder can lead to bladder rupture or inflammatory bladder disease.
• Iatrogenic urinary tract infections have been reported.

• Failure to seal vulval lips results in leakage of contrast and inadequate filling of vagina and urethra.

Refereed papers

• Recent references from PubMed and VetMedResource.
• Holt P E, Gibbs C & Latham J (1984) An evaluation of positive contrast vaginourethrography as a diagnostic aid in the bitch. JSAP 25 (9), 531-549 Wiley Online Library.
• Johnston G R, Stevens J B, Jessen C R et al (1983) Complications of retrograde contrast urethrography in dogs and cats. Am J Vet Res 44 (7), 1248-1256 PubMed.
• Feeney D A, Thrall D E, Barber D L et al (1979) Normal excretory urogram - effect of dose, time and individual dog variation. Am J Vet Res 40 (11), 1596-1604 PubMed.

Other sources of information

• Silverman S & Long C D (2000) The diagnosis of urinary incontinence and abnormal urination in dogs and cats. Vet Clin North Am Small Anim Pract 30 (2), 427-48 PubMed.