We’re going to look at a minor oronasal fistula repair in a dachshund who had the left maxillary canine tooth extracted, initial closure, and then two additional attempts to close this fistula which were both unsuccessful. The second they achieved a little bit more closure than on the first attempt but, you can see there’s still a fistula there.
I think there are three reasons why these fail. One is because there’s tension, two is because the patient gets to the area and causes trauma and disruption to the suture line, and third we’re resolving here. What we’re doing is we’re using a fine diamond tapered bur and were removing the epithelial around the palatal mucosa and then we’re going to do the same gently to the alveolar mucosa that’s dorsal there in the video that is attached to the bone underneath.
That’s what we’re doing right now, we’re just taking and we’re removing very gently a millimeter or so of epithelium so that when healing starts, that epithelium won't have an opportunity to migrate down into the area between the two edges that we're going to suture together being the mucosa and the palatal mucosa in time to cause that not to heal.
I think that's one of the biggest reasons why these things don't heal, with the exception of tension, is because we fail to do that.
With that complete 360 around that lesion, now what we're going to do is take a scalpel and just incise the area adjacent to the underlying bone and then once we’ve done that, we’ve created a path for our periosteal elevator to go all the way down to the bone to start to elevate that mucosa off of the bone.
You're going to have a lot thicker tissue there than you would normally if you were doing an extraction because that fibrous tissues has had a chance to organize and adhere to that underlying bone. What I like to do is get that fibrous tissue off. It’s much easier to get that elevator down there and really put some good pressure on it as you see we’ve done and then come back and dissect the mucosa from that underlying tissue to give it more resiliency.
What we’re doing right now is we’re using that periosteal elevator, the larger end, and getting a little bit more aggressive there.
Now we've got that open and we will take and incise that thick granulation tissue, or actually fibrous tissue, off of the palatal aspect of that mucosa, trim it away, and create a nice flap that has no tension prior to closure. You see we’re doing that there, we’re going in the mucosa interface between that mucosa nad that fibrous tissue and then we’re just going to cut right along that margin and start to disrupt that communication between those two tissues. Then as we progress, what we're going to do as we're doing here, we're going to trim away that thick tissue, create a nice margin at the edge there to be able to suture back.
There we go, we're trimming that away. Going to trim that away, make it nice and resilient, make that tissue nice and mobile so that we can see suture it back.
Again, the key here is no tension. You see we’re getting pretty aggressive there, right underneath that fibrous tissue. There's a little bit of it there coming through. We’re going to clip that. Now we’ve got a nice, resilient flap that we can suture back to that palatal mucosa.
We've got that little 1 mm or so margin where we've taken that epithelium off and now we’ve got connective tissue underneath that that will allow us to have a zone that will facilitate healing and not have to worry about that epithelium migrating into the area between the edge of the mucosa and the palatal mucosa.
There's a small vertical component on all of these in the back. You'll want to suture that vertical component going distal to mesial and then once you've done that, then you can start on the actual suture line down at the palatal mucosa.
Now we proceed up to the next location. You want to take the big bites here. There’s no reason be conservative as far as the bites go. You want nice big bites in the palatal mucosa, in the vestibular mucosa, and then simple interrupted sutures all the way through. We do a double pass around the pickups for our first with two throws, tie that and then go back two single throws again. Surgeon's knot and then two single throws. Tie all three of those and we're ready to go. We use 4-0 Monocryl for these. If it's a really large dog we might use 3-0 but, not really commonly. If you've got a really small dog, certainly can consider 5-0 Monocryl but, they do quite well with with 4-0.
Here we're progressing forward, you can see there's no tension on that. There's a little vertical component there as well so, we go in then into the mucosa, tie that and that will complete the procedure.
One thing that you need to keep in mind, one of the things that I said that could result in failure here is the patient getting to the area with their paws or rubbing their face on the floor. You always want to use an elizabethan collar and discharged that with two weeks minimum, possibly three weeks for the dog wear and make sure that the owner knows that the only way that this is going to fail is if the dog gets to it.