The big gaping hole in the skin…

Vet student in surgery

Something that is said a lot by surgeons is that unless you do something then you will never understand just what it takes. I realised today that this feeling depends on what you are doing. For routine stuff such as castrations where the goal is to remove some organs through a small tidy incision with no impact on function I am confident. I know what I am doing, how to do it, and that everything is going fit back together afterwards.

Today however I was put into a new situation, I assisted on an amputation after a car accident, and was left with a big hole on the side of the chest to cover with skin. I was basically doing reconstructive plastic surgery for the first time – and I started to feel the pressure. I had to make sure that the skin came together without tension without any dead space and with good opposition. I started walking the top flap down across the open space suturing it to the underlying muscles as I went. Once I had reduced the space here I realised that the edges did not line up – it was my responsibility now to cut the skin so that it fit together. For the wound to be straight with no dead space as if I left space underneath the skin it would form a seroma and fill with fluid. This has always looked so easy when someone else is doing it, however now it was me and it was not so easy. This was the easy wound as there was not going be much movement here yet I was still not sure just how much I could or should take.

I did the only thing I could that made sense and did it in stages as I brought the skin back together and it worked. Nothing like the results in the textbooks – however tonight I am going sleep fine with confidence that it was a good job and will heal.

The next part of the surgery was to repair a wound on the back leg as well – the skin had been peeled back either side of the thigh from the front with dirt inside with really dirty edges. This time it was more difficult to judge – this wound was going have movement across it with every single step. Every step was going change the tension on this wound, and it was big from the top of the thigh all the way until just above the top of the knee. Normally the length is not a consideration (wounds heal side to side not front to back!) – however the closeness to the knee meant that different tension patterns were going apply to different parts of the wound.

I made my plan; I picked up the scalpel, placed it against the skin roughly 3mm from the torn edge and started my cut. My cut was long and went around the entire wound taking in a random hole at the lower end as well. It was slow, and I was petrified that I was going take too much, or worse go too deep and cut something I shouldn’t. As I cut there was bleeding – I’m lucky I know more about bleeding now than most – and seeing this blood I was concerned but not alarmed as it was only a little. I clamped it off whilst I finished my cut – clamping it applied pressure and gave it time to clot so that by the time I was going suture the wound it would have stopped bleeding.

I then set about cleaning the surface of the open wound that had been contaminated with a curette (like  sharp edged spoon) so that I had a clean wound bed that would stick to the skin I was going place over it. I took my now relatively cleaner wound and then flushed it with sterile saline to hopefully remove as many germs as possible that I may have missed and started suturing it back together. Firstly bringing the edges of the skin close to each other, and then suturing the edges of the skin together.

Finally it was time to head to recovery – which went extremely smoothly with the dog up on its 3 good legs within 30 minutes of the end of surgery. I just hope now the dog finds an amazing home.

Dehorning and holes into the skull…

Dehorning cows - a hole into the skull

Friday again, another morning spent on the farm working with the dairy herd in diseases of ruminants. With Easter so close a lot of people have travelled home and so today’s group is really small. Last time was reproduction work so today is orthopaedics and other surgery unrelated to the reproductive tract including today dehorning.

Cows are generally gentle loving animals, however their heads are one of their primary weapons, and with horns they are actually quite formidable. This endangers workers, plus also the other animals in the herd. Most of time the tissue that grows the horn is removed when they are calves so that the horns do not grow, however if there is a problem with this then the horn can still grow.

These horns are basically made keratin which is the same as your finger nails – however in cows after they reach about 2 months the horn “bud” attaches to the skull underneath and the sinus cavity inside the skull will expand into the horn as it grows. This is where the photo is from – it is the hole that is left after the horn has been removed looking into the frontal sinus.

The horn has a nerve going to it (the cornual nerve) which goes from behind the eye so before we do anything this is blocked by using procaine as a local anaesthesia which means that there is no feeling anywhere around the horn.

After the horn bud attaches to the skull at around 8 weeks only a vet is allowed to remove it – farmers can only remove the tip of the horn so that it is not sharp. Removing the tip however doesn’t remove the danger as it can cause significant bruising and damage to others. So at this stage it is still beneficial to remove the horn, this is done by a surgical wire saw and usually takes under a minute to do (the record here is apparently 17 seconds). Once the horn is removed any bleeding from the blood vessels is controlled by ligation and antibiotic spray applied to the site.

Unfortunately this is the only way to remove the horn, and there is not enough loose skin in this area to close over this so it is left open. It takes around 4 weeks for a scab to form over this opening – and then a further few weeks for it to form a proper scar.

This does not cause as many side effects as may be expected – having a patch over the hole with a bandage is generally not liked by cows and they tend to remove it within hours. And from the studies I have read having a patch does not reduce the healing time. The only recommendation here is to keep the cows that have been dehorned separate to the rest – this is good from a management point of view as it is easier to check that nothing is going on with them.

The rest of the morning went do checking on some patients post digit amputation. One of these had a large abscess higher up the leg which was removed. This lead to some bleeding and I was allowed to ligate the bleeding vessels here. Today was my first suturing ruminants and it was pretty different for me with how thick and tough the skin is so I was pleased to get the practice. However even after ligation of the main bleeding vessels there was still significant capillary bleeding and so we applied a tourniquet to the leg to reduce the blood flow and allow clot formation before we released the cow back to the herd.

We were pretty disgusting when we finished, however went straight into lectures for contagious disease… The joys of vet school.