Sunday, July 15, 2012

Animal shelter surgery: autoligation

When I watched my first video on how to spay a dog, lo these many (two) years ago, I kept saying “what’s a pedicle?” Apparently it was very important to tie the suture around the pedicle very tightly. And from context it was clear that the pedicle was the bit of tissue connecting the ovary to the body wall. But what was it?

I finally figured it out. The pedicle is the bit of tissue connecting the ovary to the body wall. It isn’t really anything in particular, it isn’t any actual anatomical structure, it just holds the ovary in place. But blood vessels run through it, so when you cut it in order to remove the ovary from the animal, lots of bleeding can happen. Bleeding is bad, particularly if it continues after the animal is closed up. So one of the hardest and most important parts of spaying a dog or cat is to make sure that you wrap some suture really, really tightly around the pedicle and tie it in a really, really secure knot so that no blood can get out.

Or not.

In shelter spays, the goal is speed. Most importantly, the less time spent under anesthesia, the better. This is particularly true in the case of feral cat spays, in which the cat can’t receive optimal post-op care because she can’t be handled. Also, of course, shorter spays means you can move more animals through in a day, sometimes dozens of animals per surgeon. We are not keeping up with the cat population with surgical sterilization as it is, so the high volume spay/neuter operations really try to keep as many animals as possible moving through.

One way that shelter vets try to make surgery time shorter is with autoligation. Instead of tying suture around the pedicle before cutting it, the pedicle is actually tied to itself. It’s a lot faster once you learn to do it. There is no futzing with getting the suture around the little cat pedicle with all the big clamps around it (oops! I looped the suture around a clamp! Time to start over). Tie the pedicle to itself, cut, inspect, let it sink back into the abdomen and move on. This is a pedicle tie, also known as autoligation (in other words, ligating the pedicle with itself).

Why don’t all vets do this? I suspect some private practice vets do. However, the technique takes a little learning, so if you’re not doing at least a few spays a week, it’s not really worth the investment. One vet recently told me that his private practice only performed about one spay a month. The rest were done in shelters, and that was fine by them.

And that’s one of the ways in which shelter surgery is different from general surgery.

This post written in celebration of my first unsupervised pedicle tie.

Wednesday, July 4, 2012

Day Two

I didn’t really feel like a vet until the second day of my veterinary internship in shelter medicine. I spent the first day being driven from department to department in the blazing heat to get my email address working (it still doesn’t), turn in medical records (not yet successful), and get my ID (the photo isn’t great, but a lot better than what I had managed on my first day of vet school).

The second day was different.

My alarm went off at 4:45 am. In New England this close to the summer solstice it would have been at least dawn if not full light at that time of the morning, but here it was still pitch black out. This may be due to being closer to the equator or to being farther west in the time zone, take your pick. Exercising the dogs was a little scary, because this town is home to the largest (flying) cockroaches you have ever seen, and they come out at night. (I survived.) My intern-mate arrived at my house at 6:15, and just as the sky was lightening we got in the car.

We drove for an hour and a half, getting to know each other on the way. We have known each other for a little less than a week now, but expect to be spending long hours together, so our relationship is sort of on the fast track. We talked about family and vet school. While I drove, she read aloud off her smartphone about a large hoarding case we will be working on in a few days.

We arrived at the shelter/hospital complex a little before 8 am. The senior resident drove up a few minutes later, fresh from the coffee shop. Warm drinks were distributed. I am still amazed that people down here drink hot drinks at this time of the year. At 8 am it was not yet sweltering, but well on its way.

We started the morning in the veterinary clinic, doing surgeries on shelter animals. Dr. Intern-mate and I had both gotten married after graduation from veterinary school but before the beginning of this internship, and we shared a moment of surprise when scrubbing in for surgery at discovering that now we had to deal with what to do with our wedding rings. It is a common problem with surgeons that rings get removed and then lost; neither of us had come up with a good plan yet for dealing with ours, and just stuck them in our pockets.

I neutered a cat and two dogs. I declined to spay a cat who was pregnant; I have spayed pregnant cats before and I will do it again, but it still makes me uncomfortable, and since I was offered a choice of two animals, I took the male. I may regret the decision, as spays are much more difficult than neuters, and I could have gotten some valuable instruction from Dr. Senior Resident on a new technique I’m learning.

While I only participated in sterilization surgeries that day, I observed two tail amputations. Why were so many cats with severe tail trauma coming in that day? (I saw a third get scheduled for an amputation as well.) Just lucky, I guess. I saw a dog get two stones the diameter of quarters pulled out of her bladder. (Ouch.) Then a technician appeared with a tiny kitten in a carrier, and announced that the kitten had some sort of wound in its neck which appeared to be infested with maggots. Dr. Intern-mate and I immediately bailed on surgery observation and went to give the kitten a physical exam.

She was a tiny grey kitten with a head way too big for her body. While an outsized head is somewhat normal for a kitten of this age, four to five weeks, she was clearly undernourished. Most of the fur was gone from the right side of her neck, and the nearby fur on her shoulders and chin was matted. She had a huge swollen mass on her neck, with a hole in her skin maybe 2 cm in diameter, and a dark mouth sticking out. It looked like a curled worm to me at first (though clearly not a maggot), but Dr. Intern-mate had seen this kind of thing before and declared it to be a fly bot. The mouth was pressed up against the hole for it to breathe. We cleaned the skin as best we could, and as we pressed against the bot it retracted deeper into the skin. (Everyone who encountered this bot reacted by exclaiming that it was gross, but after that you can divide the reactions into two camps: Tell me more! and I’m leaving the room now. Which are you?)

Image provided by Wikimedia

Dr. Senior Resident finished up her surgery and came over to see the kitten. We sedated her, then, when her eyes remained wide and her head remained up, put a mask on her to deliver anesthesia gas. When she was out we dripped a little local painkiller on to the area, and Dr. Senior Resident opened the hole up with scissors. She pulled the bot out with forceps. It was huge, almost as long as but much fatter than my thumb, and especially large to have been pulled out of such a tiny kitten. It was very definitely alive, and undulated sluggishly around the table while I filmed it on my smartphone. (Smartphones are the star of today’s story.)

Dr. Intern-mate and I also tried to draw blood from a stone, er, a very dry cat. She was dehydrated and sick but sweet. I felt bad poking her and wished once again that I was better at it. A tech saw how long the draw was taking, came over, and in the way of all techs, slipped the needle in and extracted plenty of blood in very little time. I try hard to get as much experience as I can with blood draws, because I think being able to do them is important, but it’s always hard when I feel that I am hurting an animal with my inexperienced prodding. I did fulfill my doctorly duties by reporting the cat’s dehydrated and flea-infested status to Dr. Senior Resident and making sure that both things would get taken care of, but I felt very much like a student at the moment.

After lunch, we began the medical (rather than surgical) portion of the day. Much of this consisted of checkups on animals who were either healthy (but we didn’t know that yet as they had just arrived at the shelter) or being treated for something previously diagnosed. I did physical exams on two teenage kittens. Both looked great, but one had a little bit of red around her eye. This is a good example of how shelter medicine differs from general practice. In general practice, a slightly red eye is not really worthy of note unless it goes on for a few days or gets worse. In a shelter, it is a sign of impending upper respiratory infection (URI), which about half of cats will come down with while in the shelter environment. URIs don’t kill very many animals, but they do keep animals from being adopted out of shelters while sick, and they of course add expense to managing animals. I recommended just keeping a close eye on this kitten, and Dr. Senior Resident agreed.

As the afternoon got hotter, Dr. Intern-mate and I headed over to the dog kennels to do some physical exams and give some rabies vaccinations. One dog was recovering from kennel cough, so we had to don Personal Protective Equipment (PPE) to go in to his run. This entailed putting on booties, a gown, and gloves over our scrubs. The dog runs were not air conditioned. On an already miserably hot day, it was almost unbearable: welcome to the South. Hopefully I will toughen up as this summer goes on.

Finally, Dr. Intern-mate and I headed over the the kitten house. Kitten house! It is an entire little house, a few blocks from the main shelter, entirely dedicated to housing kittens. It is staffed by volunteers, and the main room has rocking chairs for them to sit in with kittens on their chests. The cuteness was unbearable. Dr. Intern-mate and I were sent in to the Upper Respiratory Infection room (again in PPE, but this time there was A/C) to weigh, feed, and medicate about 40 kittens. They were in a rack of cages against the wall, and as they were mostly feeling pretty good with their medications (yay) they were all bouncing off the walls of their cages. It was hilarious. The next hour or two were populated by the sounds of kitten bodies hitting all possible sides of the cage (including the top), and Dr. Intern-mate saying things like “oh no, you mustn’t bite me in the face” and “it’s not nice to beat up on your sister like that.” My favorite moment was possibly when one kitten escaped from her and got under the rack of cages. I closed the door to the room while she fished him out. As she went to put him back, we realized from the records that he had come out of the wrong cage (which cleared up some confusion as to why there had been only two kittens in the previous cage, when the records suggested there should be three). So far as we could tell he had been in the wrong cage for several days. With the level of chaos in the room, we could easily see how it had happened. We had a good-natured argument about which cage to leave him in. I won with the argument that his original cagemates were on medications which he was supposed to be getting as well.

Finally the day was over. I was exhausted, hot, and hungry; we had been working for eleven hours. We piled back into the car and set off on the hour and a half drive for home. Twenty minutes in, Dr. Intern-mate realized her wedding ring was not in her scrub top any more. It must have fallen out. Yes, we turned around, and it was right were she suspected it would be, but at this point I was not sure I would survive the trek home without food. I pulled the hero of the story out of my pocket, and it told me that an excellent “fit for foodies” restaurant was very near by. We went, and ate the best fried zucchini you can imagine, along with a very good noodle dish which I could barely stuff in after the amazing appetizer. We finally got back on the road, missed a turn, drove for quite a while in the middle of very dark nowhere under a lovely harvest moon, hanging on every word of the smartphone as it guided us back to civilization.

I got home sixteen hours after I had left. I think this day was a sign of good things to come in the internship. I’ll let you know how it goes.