Okay, so this is a talk on very difficult insertion, the angulated sigmoid and the redundant colon. Some of the things Dr. Rex has already covered, so that makes my job easier, let's see. So one of the main, what is a good colonoscope insertion technique? And what I mean by that is you've got to use, you've reached the C-cum with the least amount of scope insertion using good technique, straightest possible scope without loops, least amount of colon distension with gas insufflation, and avoiding complication by not pushing against fixed resistance and avoiding and reducing loops. Now the colon has certain anatomic variabilities and considerations that we should keep in mind. It is a mobile structure that affects, all this affects the insertion phase. So it is mobile. It can be stretched and elongated, especially the sigmoid and the transverse as well as the flexures. There are certain areas of the colon that have sharp turns and twists, example the rectosigmoid, the sigmoid colon, and the flexures, and the colon, how it behaves during the insertion phase is also impacted by the body habitus, presence of fat, intra-abdominal fat, scarring from prior surgeries, presence of diabeticculosis, hernias, prior history of radiation, as well as ascites. So if you look at the difficult insertion, there are two types of difficult insertion, either there's a sharp angulation or it's a redundant colon which leads to excessive looping. So what we all should do before we do a colonoscopy, and especially when we are doing the consent process, consent, taking the consent, we should take a good history of previous abdominal surgeries, history of radiation therapy, history of prior episodes of diabeticulitis, do they have hernias, what has been their previous experience with colonoscopy, because sometimes patients will tell you that, oh, they had a very tough colonoscopy, the doctor came out and told them it was a very loopy redundant colon. So that all preempts you that, okay, this will be a difficult insertion. Always examine the abdomen. I tell this to my fellows, when they take consent, at least put a hand on the abdomen and examine the laxity of the abdominal wall. Is it distended? Are there any surgical scars? Are there any hernias? Always try to review any previous colonoscopy report if it's available, because that can help you and actually caution you or warn you that what lays ahead during this procedure. And always anticipate a difficult insertion so that you can take appropriate measures preemptively. And what I always tell the fellows, and I do it as a rule, is describe the difficulty in your report. If you have a difficult insertion, describe that in your report. Also describe the measures you've taken to successfully reach the CECM, because, you know, the same difficulty you'll encounter if you do a follow-up colonoscopy later on, and that will just help you for future reference. So let's talk about the angulated sigmoid, more common in women with low abdominal or pelvic surgeries, also in elderly with stenosing diverticular disease. If you know that a patient is an angulated sigmoid based on your previous colonoscopy or a report, you could straightaway go to a smaller caliber scope, like a pediatric colonoscope or gastroscope. That being said, my scope of choice, by and large, is still an adult scope. So I do start with an adult colonoscope, because it loops less, I feel it gets me to the CECM faster in the majority of the situations, but in certain situations, you have to change the scope. You should always hold the scope with your fingers. I mean, the fingertips are very sensitive. You need that tactile sensation of resistance, versus this is not a weapon. I tell my fellows, it's not a weapon. You don't have to hold it like a dagger, right? So you have to hold it gently with your fingers, so you get the tactile feedback, especially at sharp turns, if there is resistance. Now, Dr. Rex already alluded to this. It's water aided, water, water, water, less gas, more water, because what gas insufflation does is it just elongates the sigmoid, makes these angles more acute, traps the air proximally leading to barotrauma, and that's a bad situation, whereas on the contrary, water insufflation or water immersion will keep the sigmoid straight, short, and less angulated, and therefore, there'll be less barotrauma, and you'll be able to negotiate these turns more easily. And also, when you're trying to negotiate the turns, try to do more torquing rather than pushing, because pushing also makes the turns more angulated and makes it more difficult to negotiate them. One of the things that you can try is by torquing, bring the turn up in the up direction, and then deflect the big dial with your left thumb up to negotiate and to make that turn. And in certain situations, you can do a very cautious mucosal slide by, but you have to be careful that you can see when you're doing this, you don't see the lumen, you're sliding, the mucosa has to be sliding. If it is not moving, that means that is a sign that there could be a fixed turn there, and that is a word of caution over there. So you do all this, and you still can't make the turn because you have to turn the small dial, then you have to free your right hand. So what you do is the left hand grip, you take the right hand off, and you take the shaft of the scope between the little finger and the ring finger on the left hand to hold it. And that frees your right hand, and now the right hand can move the small dial more easily for better steering, and you can push the shaft with your left hand close to the back of the patient. And obviously, the most important thing here is do not push against a fixed resistance because you will just elongate it and go through the wall and cause a perforation. What other things can help with angulated sigmoid? Obviously, abdominal pressure. The key here is right lower quadrant pressure directed medially and downward. So that is the direction. One of the things that you should always practice routinely is when you give directions or ask your tech or nurse to give pressure, you've got to tell them where to push and which direction to push. Otherwise, you'll just have all kinds of different pressures people are giving, and which might not be very productive to your attempts to insert the scope. So where to push, in which direction to push is very important. If that is also not helping, then you change the position of the patient. You turn them to supine and then apply right lower quadrant pressure. And the last resort would be, obviously, to turn to the right lateral position. And changing the scope is important, especially if it's a very tight turn. You can change to a pediatric colonoscope or a gastroscope. As these have, this is the colonoscope, this is the pediatric colonoscope, and the gastroscope, as you can see, they have a shorter bending section and a shorter, tighter turning radius so that they can negotiate sharper angulations more easily than an adult colonoscope. This is just a table to show how it helps. If you take the adult colonoscope as the reference, the pediatric colonoscope has a 10% lesser diameter. But because the area is pi r squared of the circle, the surface area is reduced by 20%. And compare this to the EGD scope, which has a 25% reduction in the diameter compared to a colonoscope and a 44% reduction in the area. So this gives you a sense why changing to a smaller caliber scope would be helpful in negotiating a tight turn. Another thing that can be tried is starting the procedure in the right lateral position. If you already know that this has been a difficult colonoscopy in the past because of a tight sigmoid turn, there is some evidence to suggest that it helps you to reach the C-cum quicker, especially in women and patients who have had history of abdominal surgery. So something to try, but obviously it's a little cumbersome and uncomfortable to do a colonoscopy with the patient in the right lateral position, but something to think about. So moving on to the redundant colon. What about if you have excessive looping? You should anticipate that. Where do you anticipate this? In obese patients, patients who have lax abdominal wall musculature, large ventral hernias, inguinal hernias, and history of chronic constipation. Again, adult colonoscope is your scope to go with because it's stiffer and resists looping better than other scopes, which are like the periodic colonoscope. How do you identify this? You lose one-to-one insertion and forward movement. You're pushing in more of the scope, but on the screen, you don't see a moving forward as much. There's resistance to insertion. There's too much of scope in relation to the location. That is something you should always, always have an idea on as to how much scope you have and where in the colon your tip is. That will give you an idea whether you have a big loop. And obviously, if the patient starts having abdominal discomfort, which obviously with propofol sedation is sometimes difficult to assess, you should always reduce. Now, loop reduction is the key to good insertion techniques, especially when you have a redundant colon. This is very, very important. You can stiffen the scope. If you have variable stiffness colonoscope, you can increase the stiffness. Again, as in the angulated sigmoid, gas is bad and water is good. So what gas insufflation does is it distends the colon and elongates the colon further. Water immersion will make the sigmoid heavy, straighter and narrower, decreases the looping and the redundancy and facilitates a secal intubation. Now, you want to recognize the loops also. So every portion of the colon, you can have different types of loops. In the sigmoid, you can have the alpha loop, the end loop, or the reverse alpha loop. Most of the times, in majority of the situation, to reduce this loop, you torque right and slowly withdraw the colonoscope, especially for the alpha loop. And what you'll see is that your tip will stay in position on the monitor while your insertion tube will come out. If this doesn't work and you know you have a loop in the sigmoid, you can try the counterclockwise torque and pull back for the reverse alpha loop. The aim overall is to have a straight scope in the sigmoid, reaching the splenic flexure region with about 40 to 50 centimeters of the scope in. Now, if you straighten the scope in the sigmoid, and then you start advancing and the loop reforms, then you have to apply pressure. Again, right lower quadrant pressure directed medially and downwards, and sometimes also left lower quadrant pressure. Obviously, water immersion will help to keep the sigmoid heavy and straight and avoid or prevent looping. What about once you read the splenic flexure? The splenic flexure can be a problem also. It can be high and floppy and can get elongated and angulated as you're passing this area. You identify this by the fact that you have a straight scope in the sigmoid, and now you're in the area of the splenic flexure, and you have difficulty entering the transverse colon, which means that the splenic flexure has become elongated and angulated. There's a sharp turn there. How do you negotiate this? Gradual torquing, turn the dials, suction the air or the gas, and avoid too much pushing because that might make the angle more acute. You apply left upper quadrant pressure below the ribs. Again, give the correct direction, left upper quadrant below the ribs, directed medially in respect to the patient's anatomy, and turn to supine position if this is not working with the same pressure, or finally to right lateral position, but that is less needed for this. Sometimes you have to apply pressure both right and the left quadrants also, forehand pressure. The word of caution here is if you're having difficulty negotiating the spleen, you have to be cautious about splenic injury. Also, after you negotiate the splenic flexure, avoid forceful torquing. If you have to reduce the scope, be cautious, gentle when you're torquing and pulling the scope out because of the risk of splenic injury as we just discussed in the previous talk. What about the transverse colon? Our transverse colon is also mobile due to the mesocolon. The loop will descend downwards. The way you give pressure is center of the abdomen directed upwards. That is the exact direction you have to give to your tech or nurse, whoever is giving the pressure. And sometimes turning to the supine position is helpful here. Now you reach the hepatic flexure. Here what you do is you might need a counterclockwise torque, suction the air and negotiate the turn. If you have a loop in this area, sometimes you can hook the flexure and gently pull out the scope to straighten it. And during this maneuver, a lot of times the tip of the scope will move forward and you'll enter the ascending colon. The loop will be reduced and the turn will be negotiated. Sometimes in difficult situations, you can turn the patient to the supine position or even halfway by rotating the shoulders away or shoulders towards you to open up a sharply angulated flexure. Now you reach the ascending colon, you pass the hepatic flexure and now you lose one-to-one progress. What do you do? You can counterclockwise torque and gentle rocking movement of the scope back and forth and suction the air or the gas. And this sometimes can help to propel the tip of the scope forwards towards the cecum. Pressure over the cecum directed superiorly or more commonly right flank pressure directed medially will help you to intubate the cecum. And if you have excessive looping, you have forehands pressing on the abdomen in different areas. In some situations, you can see the cecum, you're almost there and you're unable to intubate. What helps here is turn the patient to the right lateral position, applying pressure and you'll see that the scope tip just drops into the cecum at that point. So some things to remember. Pressure doesn't always help. So if you're having difficulty and pressure is not helping, it may be that the pressure is impeding the progress sometimes. So just keep that in mind also. Give specific directions to your tech regarding the location and the direction of the pressure. Sometimes you may need all the help that you can get to help you get to the cecum, especially when it's a very redundant colon. Be aware of the risk of aspiration, especially when we're doing propofol sedation. When you turn these patients to supine or the right lateral position and apply abdominal pressure, patients can start hiccuping and coughing. That's a sign that they might be aspirating the gastric contents. Massage the abdomen. Sometimes you can ask your tech to massage the abdomen and this can help to catch the loop and advance the scope. And at the end, obviously be ready to quit. I mean, it's humbling, right? All of us want to have a 100% cecal intubation rate. That's not going to happen, right? We will have situations where at some point you have to quit because the first principle is do no harm. Try another day. Start the next procedure with water immersion from the get-go. Apply abdominal pressure right from the get-go. Or refer the patient to a more experienced colleague either in your practice or a regional expert who's very competent, more competent in getting to the cecum in difficult colonoscopies. Now, there are certain other things that can help you. Abdominal binders, there's some data about it. This is one of the commercially available ones. These may be helpful in mild to moderate obesity, where they've been shown to shorten the sacral intubation time. And also, there was a trend towards reduction in the requirement of manual pressure, or change in positions, or something to have. I don't use this routinely, but there has been some data suggesting that they may be helpful in obese patients. What about scope guide, or magnetic endoscopic imaging? These are special scopes. Basically, the same company that I think Olympus makes this. We have electromagnetic coils incorporated along the shaft of the scope. And this generates a pulsed, low-intensity magnetic field, which is then picked up by a receiver, which generates a three-dimensional image of the scope. So here, I'm inserting the scope. As you can see, I'm creating an alpha loop in the sigmoid, and that alerts me. And you can start reducing the loop. It also helps you to apply pressure more appropriately, because you know where the loop is forming. And then you can ask your tech to apply pressure in that specific area. So here, you can see I'm getting to the splenic flexure region, and I'm having a little bit of difficulty negotiating the splenic flexure. And it's almost like making the splenic flexure more angulated and elongated. So we'll have to get pressure, reduce the loop. Here, I kind of elongated the splenic flexure a little bit. I'll reduce the loop. I'm in the transverse colon now. And see, after I reduce the loop, I negotiate the hepatic flexure, and then I'm going towards the cecum. So that's a reasonably straight scope. That is what you want. This has been shown to lower the risk of failed cecal intubation, reduce the cecal intubation time, and lower pain scores. Cost is an issue. I think these scopes are a little more expensive than our regular scope, but something to have or keep in mind that this is available. What about rigidizing over tube? This is a special type of tube that is available for redundant colons. It's extremely flexible in its native state. So you pass the scope through this over tube, and then you advance the scope to the desired location, reduce your loop. Then you pass this over tube over the scope, and you apply the vacuum, which stiffens this over tube to about 15 times. So now when you advance the scope after this, there will be less looping. And hopefully, you'll be able to read the cecum. It comes in different diameters and different lengths. Balloon over tubes have also been tried for failed colonoscopy, either single balloon endoscopes or double balloon endoscopes. And in this meta-analysis, they found that in failed colonoscopies, by far majority of the cases, they were able to reach the cecum in a reasonable amount of time frame. And the reasons for not reaching the cecum in original procedures were either excessive looping or a fixed sigmoid or excessive pain in the patient. So it's a good rescue technique to have or at least have these scopes available and use them in certain situations. A word about hernia. This can be a major problem. Actually, I've had two failures over the last 20 years because of hernias. And in both of them, we had to get the hernia repaired before we could successfully complete a colonoscopy. So for inguinal hernias, reduce the hernia before starting the insertion. And the only way you can do that is if you know about it. And that's why you talk about it with the patient when you're taking the consent. Apply pressure over the hernia inlet till the colonoscope has passed the sigmoid. And sometimes I keep the pressure on till the end. For ventral hernias, these can be also difficult. They can be large and difficult to reduce. You apply pressure to resist the scope from entering into the hernia. And changing to a smaller caliber scope or longer scope will not be really helpful here because they'll just loop more. And as I said, surgical repair may be needed before successful sacral intubation in some situations. What about referral to an expert? This is Dr. Rex's series where he was referred to failed colonoscopies. And in majority of them, 96% of them, he was able to reach the cecum successfully. And the key here was using water immersion. And what he showed was if you use water, you need less adjunctive help, which means in this case, only 6% of the patients where he used water immersion did he need an external straightening device compared to 15% when he went with gas insufflation, especially in redundant colons. If you have a redundant colon that resulted in failed colonoscopy, the need for external straightener or position change was significantly lower when you use water immersion compared to if you use gas. So always use water. Water is always helpful both for angulated sigmoid as well as for redundant colon. So in conclusion, anticipate the difficult colon. Take a good history. Examine the abdomen. Review the records if available. Use as less gas insufflation as possible. Use water immersion in exchange. If it's an angulated sigmoid, use water. Use more torquing and turning the dials rather than pushing. Use the left-handed grip if you have to free the right hand to turn the dials more or a smaller dial. Abdominal pressure, then change position and also move to a smaller caliber scope if needed. For a redundant colon, again, water immersion is helpful. Anticipate the location and the type of loop and reduce as necessary. Apply abdominal pressure and obviously change your position. Adjunctive things that can help are overtube, scope guide, abdominal binders, double balloon or single balloon endoscopes. The do's and don'ts are don't push against fixed resistance, especially without a visible lumen in front. Document the difficulty in the report for future reference and steps taken to overcome and to reach the CCOM in that case. And be prepared to quit and refer to an expert. Thank you. Thank you, Amit. That was great. There are a number of questions here. I want to talk briefly about scope choice because I'm with you. I like the adult scope for routine use. And one of my favorite things about an adult scope in the Olympus series is that it has a bigger channel. So if you find a lot of polyps, and I consider myself and I've documented high detector, I don't like pulling the snare in and out of the scope all the time. So you can actually suction polyps back around the snare through the channel with an adult scope. It doesn't work very well with a pediatric scope. So I find that to be a distinct advantage in addition to the other things that you mentioned. But I do have a set of patients that I'll use a pediatric scope. So one is, I always think about it in very elderly people, especially if I know that they've got bad diverticular disease. Diverticular disease is a risk factor in the literature for perforation. I feel that I can scope pretty much anybody without a risk of perforation. But I always say I'm trying to sneak in and out of the very elderly patient, especially with bad diverticular disease. And that means a thinner scope, less pressure on the bowel wall and underwater in that patient. But I also use it in inflammatory bowel disease. For routine colonoscopy, I like to have an endocuff on. And I think the endocuff makes it harder to get in the TI. IBD, I pretty much always want to go in the TI. And skinnier scopes are easier. I use it in patients that have had radiation for something other than prostate. Any kind of abdominal radiation, I think there's an increased risk. If you just know the bowel is really sick, I think it's better to use a more flexible scope. You're just less likely, you can't exert as much force with a thinner scope. But I would like to hear from, I think the questioners want to know, if you use an adult scope routinely, when are you going to choose a pedoscope beyond a known narrow-angulated sigmoid? Any other situations? I mean, obviously, choosing from the get-go or changing? I mean, changing is obviously, you're making a turn and you can't make a turn because you have diverticular disease. Then you'll- From the get-go. Yeah. I think what you described, how you get the history and you look at the patient, I also prefer the adult colonoscope with the channel and the stiffness. But many in our VA unit use the pediatric scope as well. I think that when I see a patient and they have, it's not just their weight, but that really thin pelvic frame combined with the age, that may push me to the pediatric scope. And then there's just the phenotype of the smoker COPD emphysema, who's that just has that small, small pelvic frame. I think that's what pushes me, Doug and Amit, to the pediatric. I will say, as a regular adult scope user, if I need a particular scope, and Amit was referring to this, if I needed a pediatric scope to pass the sigmoid, I document that right in- Totally. And plans. Yes. Because I always look at the previous report. So it's a thing I see, get a particular scope to get through. But OK. So let's see. We may have time for a couple other questions are appearing here. Any comments about how to minimize the stress injuries and so on for whoever's pushing? The SG&A has some recommendations about this, about pushing sometimes with your hand open, sometimes pushing with the fist closed. I think, Amit, you talked about not using pressure too long. You want to try to avoid injuries. Sometimes we'll have the patient stand or the assistant stand beside us, reach over the patient, and sort of pull up on the lower left abdomen, as opposed to being on the opposite side of you and pushing against. But you can get text injuries. And you want to pay attention, I think, to trying to avoid those. Yeah, I mean, again, you have to talk to the tech. I mean, obviously, they have to be comfortable. What I do is, if it's a tough colon, and we are having difficulty, and they're pressing, take breaks. Sometimes you have to say, OK, guys, let's hold off now. Because if they're pressing for a while in different areas, and you're not advancing, getting to the cecum, then always one of the things that you can ask, keep checking with them that are they having pain? Are they having difficulty now? Or give a small break. The other thing is sometimes, and this has happened to me in the past, is I've got to an area where I needed help, and then I forgot to tell the tech to stop pressing. So those are the things that you have to keep in mind, is that if you reach the cecum, then there's no reason for the pressure. And the tech doesn't know what he or she is supposed to do. They keep pressing. So give breaks. I don't know. And I'll allude to you and Natalia to tell me. I mean, I just ask them to press. I mean, if they are pressing, usually with the hand. I mean, I don't know whether there's a specific advantage of using the fist to press. Yeah, I like the pull. I like what Doug was mentioning. I think it's much more effective if they're next to me and they're pulling rather than pushing. I don't know of an injury study on that, but I find that to be more effective, so then it's decreasing time. And then to your point earlier, Amit, I think telling them exactly where to apply pressure is really key, because then that minimizes the time spent for you doing it, the procedure, but for them doing the pressure. And readjusting quickly if it's not working, right? Like in anything in endoscopy, those algorithms of where we make a decision fast and move to the next is really important, too, in terms of that particular aspect of pressure and time and such. Yeah, for sure. Because I can tell you, I mean, if you just say pressure, they'll just give left low accordant pressure, by and large. I mean, if you take 100, yeah. So that is one thing that we always emphasize while teaching fellows, is tell them where to press and which direction to press. Yeah, I think that communication is critical. And what you were both saying about only try each thing once, and if it's not working, say, nope, that didn't get it. Nope, that's not it. Because sometimes you don't know either exactly where to push, and you're trying different things. And as soon as you feel that scope start to move forward after they've made a change, tell them, now you've got it. Hold that. Hold that thing. And stay with that until it stops working. Because the same place pretty soon may stop working. I think there's a lot of questions about what to do with obese patients. Obesity is clearly an issue. And some of these patients have really long colons. We see a lot of, in the redundant referrals, a lot of patients have very high BMIs. And I think you said you want to choose an adult scope because you want to resist looping. Any other thoughts? I think the key thing is an adult scope, if you know it's a redundant colon, going underwater is just so critical. Just from the get-go, I think, I mean, that is one area where you just go into the sigmoid and just you pump 100, 200 cc's of water, suction all the air out, just sink the sigmoid down into the left lower quadrant. Right. There's a question about whether to refer patients for balloon enteroscopy. And I will just say that I, so if I have a narrow-angulated sigmoid, my sequence of events is sometimes I'll start with a pediatric colonoscope. Sometimes I'll go straight to an ultra-thin or a super-slim colonoscope. And then if I fail, I usually go to a push enteroscope, not a balloon enteroscope, but a push enteroscope because it has a very short, tight bending section and it's very thin. And it's got enough length to get to the cecum. If you use an upper scope, there are definitely some sigmoid turns that upper scopes and enteroscopes will go around that any colonoscope, including the super-slim, will not go around because it's got a broader turning radius. And plus the deflection, right? The upper scope there has a 210-degree deflection upward. So if you have the turn in the up direction, you have a better, I mean, a higher degree of maneuverability with the EGD scope. Right. But if you ask me what scope I would rather be in the right colon with doing therapy, I would rather be there with a colonoscope, the upper scope, or any enteroscope. And I've had patients where I get over to the right colon with an enteroscope and I cannot get the instruments to go down the channel. They're terrible. So if you look overall at the literature, the cecal intubation rates at centers that routinely use balloon enteroscopy are not better than what we've reported. So we tend to just very, very rarely use balloon enteroscopes but rather use the kind of algorithm that Amit described. And I think the double balloon is even worse than the single balloon. Single balloon is a little more easier to maneuver as well as pass accessories. Double balloon is very difficult.

colonoscopy techniques

angulated sigmoid colon

redundant colon

colonoscope insertion

abdominal examination

water immersion

pediatric colonoscope