Ultrasound on the inside, what is intraoperative ultrasound? (Day -236)

Vet student intraoperative ultrasound

Many people know about ultrasound, its used all the time for pregnancy check-ups in women. However did you know it can also be used inside of an operating theatre during surgery when the body is open? So instead of looking through the skin you are directly looking at the organ.

Now when you first see an ultrasound like this it is a little bit strange – as you are so accustomed to seeing the skin and muscle in front of the organ of interest. So when we put the ultrasound probe directly onto a kidney it looks very different.

In this case I’d come into the operating room during a surgery on an exploratory laparotomy just as the surgery had stalled. You see the most important thing in surgery is information – and here there was a kidney that was enlarged with an enlarged ureter (tube from kidney to bladder) which contained a stone about halfway down its length.

Now here was where a decision that was going change the cats life needed to be taken. Was the correct action to remove the stone from the ureter and place a catheter from the bladder to kidney to keep the ureter working whilst it healed? Or was the correct course to remove the kidney?

A few months before this I had read an article on intraoperative ultrasound on sonopath (they give a free student membership!) which is the best ultrasound guide I’ve come across. This basically said that using ultrasound inside the body was even better than using it outside especially with surgery so that you could take samples from lesions identified by normal ultrasound before surgery. Even when you see a lesion on ultrasound, once you open the abdomen it can be very difficult to find the lesion to take a biopsy from it so using ultrasound during surgery helps with this.

The great thing about this that I remembered was that it did not need any specialised equipment; you can simply fill a sterile surgical glove with ultrasound gel and insert a ultrasound probe into it. Then you just use the probe through the glove in the area of interest (on sonopath is suggests using sterile saline between glove and viscera however I did not remember this at the time).

So randomly I just suggested that I bring an ultrasound machine in and we take a look at the structure of the kidney before we made the suggestion. After explaining that it could be done with a glove and some gel I was sent to get the machine and sonographer. I think the weirdest part of the entire experience was that as with normal ultrasound we turned the lights off in the operating theatre to see the picture on the screen better.

Now on ultrasound it was obvious that the kidney was no longer functional, and so the best option going forward was relatively obvious. The problem here however was that we did not know the status of the other kidney – kidneys only show clinical signs after around 75% of the functional part is destroyed – so the owner needed to decide which was a bigger risk leaving it or removing it and hoping the other kidney worked. The decision was made that the kidney was going come out (a nephrectomy), and after discussion with the owner this was what happened.

The patient was sitting up completely different (partially due to the good analgesia) and now 3 weeks after the surgery the patient is doing well and is at home.