Colonoscopy: What is a Colonoscopy?

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Guest: Dr. Brenda J. Hoffman - Gastroenterology and Hepatology

Host: Dr. Linda Austin – Psychiatrist

Announcer: Welcome to an MUSC Health Podcast.

Dr. Linda Austin: I am Dr. Linda Austin. I am talking today with Dr. Brenda Hoffman, Professor of Medicine at the Digestive Disease Center, Medical University of South Carolina.

Dr. Linda Austin: Dr. Hoffman walk us through the procedure of the colonoscopy from your point of view, what are you looking for?

Dr. Brenda J. Hoffman: After I have the patient sedated, then I would use the colonoscope to actually make my way around the entire colon to where the small bowel hooks into the large bowel and in doing that sometimes my son thinks that I play video games all day because of the screen images that we see, but we do not get a great look at the colon going in. We get the best look as we are coming out and what we are doing is looking at differences in the lining of the colon. The colon wall is very thin. I can actually read surgical instruments through it if we are doing a combine procedure. So, it is very thin, it has lots of blood vessels in it to help it perform its function of reabsorbing water. So, it is nice and smooth and has distinctive landmarks. When we see things that are irregular there, we think of those as not belonging and these growth may be flat in the colon or they may be actually more exophytic or growing more like a bush or a cauliflower if you flow red if you would and it is our goal to remove those in their entirety and to send them to pathology to be analyzed.

Dr. Linda Austin: So, is it pretty obvious to you then I mean obviously your experience, but is it fairly obvious when you are looking at something if it’s normal versus something that you need to biopsy.

Dr. Brenda J. Hoffman: Most of the time it is, there are subtle changes that can be missed and there are areas where we go around corners or we have folds that are difficult that do account for the miss rate in colonoscopy. The actual miss rate for cancer among experienced gastroenterologist is less than 1%.

Dr. Linda Austin: So, it’s highly sensitive.

Dr. Brenda J. Hoffman: It is a very sensitive and excellent test. You have to look at the credentials of the individual performing it to know if they will fall into that category because the miss rate can be higher and the complication risk higher if they don’t have appropriate training.

Dr. Linda Austin: How do you suggest that someone ask that question?

Dr. Brenda J. Hoffman: If a person is trained in an appropriate fashion, they will not be offended by that question and there are actually societies that have their membership listed for people, who have to have undergone certain training to be credential for that. So, individuals can check on the web to see if the doctor that they are thinking about allowing to perform their procedure has those credentials.

Dr. Linda Austin: What site will they go to?

Dr. Brenda J. Hoffman: One of the most commonly used is the American Society of Gastrointestinal Endoscopist or the ASGE. They listed the American College of Gastroenterology and also the American Academy of Family Practice have listings of individuals, who have undergone training to perform these. You may also have the training under the guidance of the surgical societies as well, but I don’t know exactly their websites to search. It is not inappropriate to ask an individual how many they perform per year because it correlates with their outcome and your outcome as well because certainly you want someone, who knows what they are doing and is capable of handling whatever they find there.

Dr. Linda Austin: Now, obviously you send this off to pathology for a really definitive diagnosis, but are you able to have a pretty good hunch just by what you see with your naked eyes to whether something looks like it would be cancer or not?

Dr. Brenda J. Hoffman: Absolutely, there are findings to the eyeball in terms of shape, color, and what looks like invasiveness that really tell us from the beginning when we can come out after the procedure and say, I am very concerned about this and I think this is cancer and it will have to be removed. We still await the pathology to confirm it, but there certainly are characteristics that guide you. There are also appearances to polyps, which give you a suggestion that they are more likely to be the precancerous type, but that’s not a 100%. The best thing is to take them out.

Dr. Linda Austin: Do you have statistics on roughly what percent of people, who have a colonoscopy end up having a biopsy as a result and then what percent of those end up being cancer?

Dr. Brenda J. Hoffman: There are actually accepted guidelines for competency that list those findings and for males about 25% of the time you should find adenomatous polyps of the colon. In females, it’s a little bit less more towards 15%.

Dr. Linda Austin: Adenomatous means?

Dr. Brenda J. Hoffman: Means, the kind that may change over time and be at risk for malignancy. If you look at the biopsy rates that’s not as mandated for competency, but I can tell you that I reviewed our divisions work last year and it is around 50% of the time that patient have a biopsy, many times it will be something that is not precancerous. It will be something of a different type of polyp that has less risk.

Dr. Linda Austin: What happens then if it -- I mean, I am assuming if the polyp is not cancerous, the person is good to go. Although, do they then get referred back for another colonoscopy earlier than if there are no polyps?

Dr. Brenda J. Hoffman: Yes, and at the time of endoscopy, you can have different things done to take care of the polyps. Sometimes they are very tiny and you can remove them with what’s called a biopsy forceps. Sometimes they are larger and we remove them by what looks like a lasso, a wire lasso that’s called a polypectomy and we will try to remove them whole. Sometimes they are flat and have to be lifted to be removed or they will be large and you have to piece them out and that also changes your interval for when you have to be seen back. Once they go to pathology, they will tell us about changes in the polyp that make them high at risk and that again alters when you have to be seen back. How big was it, did you get all of it, is there any possibility that there was a little left on the side, and does it look very aggressive under the microscope alter what we have to do. But let’s say that you had some simple polyps that were removed. If you had two or less of the adenomas, then you would have a five year follow-up. If you have three or more, then it’s a three year follow-up, and of course the more you have, the more we worry that you have a significant predisposition toward the colon cancer.

Dr. Linda Austin: Doctor Hoffman, thank you so much for talking with us today.

Dr. Brenda J. Hoffman: Thank you.

Announcer: If you have any questions about the services or programs offered at the Medical University of South Carolina or if you would like to schedule an appointment with one of our physicians, please call MUSC Health Connection at 1-843-792-1414.

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