September 30, 2017
Tests needed before urethroplasty
Uroflowmetry: Testing the urine flow rate
This is the first step. “The normal urinary flow rate in young and middle aged men is generally greater than 15?ml/second and the flow pattern a bell shaped curve. ” “In those who have a urethral stricture the peak flow rate is typically low but the flow pattern is characteristically flat” [Source]
“With a flow rate of less than 5?ml/second, abnormalities such as those listed above are much more likely and the patient is potentially at risk of acute retention, although this is a lot less common than one would expect from the severity of the narrowing of the urethra that is seen in such a situation. In these patients treatment is advisable even if symptoms of voiding difficulty are not troublesome.” [Source] (Sanjeev: I’m having pain while voiding)
Both “RUG/VCUG is costly and some-times logistically difficult to perform, and exposes men to radiation” [Source] These tests “show the exact site and length of the stricture and most of its potential complications” [Source]
Retrograde urethrogram (RUG)
See Wikipedia entry.
The penis is postioned at approximately the 10 o’clock position. The round opaque structure in the distal penis is the inflated Foley balloon. The Foley catheter tip is faintly radiopaque, but can be better seen as a filling defect after administration of contrast. [Source]
Voiding cystourethrogram (VCUG)
See Wikipedia entry.
The voiding urethrogram evaluates the posterior urethra. The Foley balloon is advanced into the bladder and contrast is instilled until the bladder is dilated. The bladder should be so dilated, that the patient “feels like he absolutely needs to pull off to the side of the road so he can urinate”. The Foley is then removed and the patient is encourage to urinate. Images are obtained of the open posterior urethra. As this is not a dedicated cystogram, imaging the bladder is a secondary concern. [Source]
“If the stricture is long and/or located in the penis, the stricture may be open or removed and the area is more commonly patched or less commonly replaced with a tube, made from surrounding tissues, such as nearby skin or from tissue removed from other areas in the body such as from the inside of the cheek (buccal mucosa). ” [Source]