The twists and turns of research
It’s common knowledge that no matter how well you prepare, research experiments never go perfectly according to plan.
I think back to this idea as I watch a team of veterinary specialists try, for the fourth time, to unsuccessfully place a catheter into the spleen of an anesthetized dog.
“It [can be] a little bit frustrating sometimes just because it’s never as easy as you think it’s going to be in your head,” admits Dr. James Montgomery, my research supervisor and a medical imaging specialist at the Western College of Veterinary Medicine (WCVM).
I nod in understanding. Our ultimate goal in this experiment is to reach the portal vein, the blood vessel that carries blood from the intestines and spleen into your liver.
Ideally, we would use a needle to enter a blood vessel in the spleen with the help of ultrasound images and then pass a catheter through that vessel into the portal vein.
“All of the nutrients that you get from food ends up in your portal blood, so it’s definitely a very important pathway in the body,” explains Montgomery.
If our experimental method is successful, it could open a lot of doors for further research. “[We could] have the ability to give drugs like chemotherapy agents directly to the liver and try to see if that can cut down on some of the side effects.”
It could also be important in nutritional and pharmacological research in assessing how well food or drugs are absorbed into the body. Direct access to the portal vein also lets us study liver disease in dogs and compare them to similar diseases in people.
Although our experiment is simple in theory, it’s much more complicated in practice. For every smooth run, there’s one that doesn’t go accordingly. I watch the specialists as they make one last attempt to pass the catheter into the canine spleen. This is the most frustrating complication of all: when it seems like everything is right, but somehow it just doesn’t work and no one is quite sure why.
The researchers decide to move on to the next part of the experiment – examining the abdomen with computed tomography or CT. CT uses X-rays to take a picture as a slice through an object. It’s similar to a radiograph, but CT combines hundreds of slices together to form a highly detailed, three-dimensional image.
“If there’s chronic disease in the liver, it causes the blood flow to back up into the portal vein,” says Montgomery. He explains how we can inject contrast medium into the blood to allow us to see blood flow on the CT scan.
“[We can] time how long it takes for the contrast medium to get [to the portal vein] and calculate, based on changes in that length of time, whether there’s increased blood pressure.”
If CT can accurately predict blood pressure in the portal vein, then animals may be spared more invasive procedures like our catheterization technique. It’s this potential use for CT that prompted Montgomery to develop this project. Although advanced medical imaging technologies such as CT are increasingly used in veterinary medicine, there’s still a lot that has yet to be explored.
“I think there’s a lot we do in human medicine that we could do in animals, but we just haven’t quite advanced that far yet.”
As we watch the CT images come up on the computer, a disturbing picture develops. This experiment was supposed to be performed on healthy dogs so we could have normal values; however, the image on the computer screen clearly shows that this patient has an abdominal tumour. The reason we were unsuccessful in our technique becomes clear.
As we make preparations to stop the trial, I think again about research and its unexpected challenges. Although I admit it can sometimes be frustrating, I also realize it’s this same unpredictable quality that keeps research dynamic and interesting.
Lyndsay Kong of Calgary, Alta., is a fourth-year veterinary student who participated in the WCVM’s Undergraduate Summer Research and Leadership program in 2013.