Sunday, September 18, 2011

618. Urethral Obstruction in the Dog: Retrograde urohydropropulsion

Each vet has his own way of handling a case of urethral obstruction in the dog. The outcome may be similar in that the dog can pass urine normally but the post-operation complications and implications vary.

In the following case, the Miniature Schnauzer dribbled urine. X-ray showed the urethra blocked by more than 10 small stones 3x5 mm in diameter. The catheter was obstructed and could not pass into the bladder.

1. Cystotomy and retrograde urohydropropulsion of the stones into the bladder.
2. Cystotomy and urethrostomy.

When there are too many stones, I usually take the second surgical approach. There will be less trauma to the glans penis and urethra as the urohydropropulsion (syringing 20-35 ml of water to push back the stones into the bladder). I will make a 0.5 mm cut behind the os penis, take out the stones with a forceps, close the urethra and skin. Then I take out the 3 stones from the bladder. In my experience, the urethral wound heals well if proper post-op care is given.

However, in some cases, the dog is sent home within 2 days after surgery. There is a lack of care by the owner due to inexperience in animal nursing. The wound breaks down and the urine leaks from the wound perpetually. This is because some owners do not bother to refer to the vet on seeing the wound breakdown, owing to various reasons. So, the first approach eliminates this post-op complication of an unnatural urethral gap as the penile urethra is not incised. All stones are taken out via the bladder in the first approach.

In this case, Vet 1 preferred the first approach. There are more than one surgical approaches in treating urethral obstruction and each has its own pros and cons.

However, on Saturday (my day off and 24 hours after surgery by Vet 1), I visited Toa Payoh Vets to check on this Miniature Schnauzer in the afternoon. I noted the glans penis was much swollen and so did the owner.

In this case, the dog was scheduled to go home 48 hours after surgery. The owner was concerned about this swollen glans penis - reddish and not able to get back inside the prepuce. This swelling is a post-op complication of retrograde urohydropropulsion in some cases. What makes it occur? It is due to the traumatic pressure of gripping the glans in the process of retrograde urohydropropulsion via a catheter.

Numerous small urinary stones inside the os penis (penile bone) can be removed via a urethrostomy or via flushing back into the bladder and removed via cystostomy

The Miniature Schnauzer dribbles urine for the past 2 weeks. Partial urethral obstruction with >10 small stones is seen in the X-ray. Cystostomy and urohydropropulsion removed the stones via the bladder. The owner and I see dog peeing normally as seen 2 days after the surgery before going home.
he catheter has not been able to pass through more than 10 cm inside the penis as its passage is obstructed by the numerous stones inside the penile urethra. To prevent it being dislodged as water is pumped into the catheter to push the stones back into the bladder for removal, the glans penis has been gripped as an anchor point, resulting in swelling. Gripping the penile bone may not be practical but will be preferred. In any case, the outcome was excellent in the sense that after 3 irrigations, the stones were pumped back into the bladder where they were removed. So, the penile urethra is not cut open.

In this case, there was a problem. I had to intervene to resolve this problem. I decided to give an anti-inflammatory pred injection which is not normally used after surgery. Leaving the glans penis to shrink will take many days and any traumatic injury to it will lead to much unhappiness for the owner as it will cost her money.

Although the dog has a big size 20 e-collar, the owner disagreed with me that the dog can can't reach his surgical area to bruise it. There was a small bruised area near his sutures (see picture). The lady owner told me that there was no way her dog could have licked that area since he had the collar. I said it was possible but there was no point arguing with an owner as she had not seen incidents in other cases.

Within 24 hours of the injection, the glans penis had shrunk by 50% and was much less inflamed (see picture). He peed normally, had a good appetite and an excellent caregiver. He was sent home on Sunday.

For dogs with swollen glans penis, it is best not to send home till the dog has recovered but that would take many days and trauma could still occur in the Surgery. NSAID does not work very well in such cases if they are given as the "first line of defence." NSAID was prescribed for the home stay.

More pictures are at:

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