Hi, I'm Doug Rex from Indiana University Hospital, and welcome to this DVD on colonoscopic polypectomy. This DVD is sponsored by the American Society for Gastrointestinal Endoscopy, and is a companion to a DVD on colonoscopy technique. Topics we'll cover in this video include preparation for polypectomy, visual analysis of polyps prior to resection, safety issues in polypectomy, techniques in polypectomy, including forceps and snaring techniques, high-risk polypectomy, such as large penunculated polyps and large sessile polyps, the use of ancillary techniques, including detachable snares, clipping and tattooing, polyp retrieval, the principal complications of polypectomy and their management, and post-polypectomy surveillance. These sections can either be viewed in sequence, or you can use the table of contents to go directly to sections that are of interest to you. The most common and the most important goal of colonoscopy and polypectomy is to clear the colon of neoplasia, and thereby to prevent incident cancer and death from colorectal cancer. To accomplish that, we will want to detect all of the neoplasia that is present, and to remove it effectively. Recent evidence has suggested that a much higher number of patients than previously expected developed colorectal cancer in the first few years after a negative colonoscopy, or one that had apparently cleared the colon of neoplasia. Of the various explanations for this occurrence, one of the possibilities is ineffective removal of adenomas, especially of advanced adenomas. Pabby et al. evaluated 13 incident cancers that occurred after colonoscopy and estimated that four of those 13 cancers had developed in the area where an adenoma had been removed. This association doesn't prove that ineffective polypectomy resulted in the development of cancer, but it's suggestive. Another important goal of polypectomy is to remove polyps with a minimal number of complications, such as perforation and bleeding. Finally, after completing polypectomy, we need follow-up to be both effective and cost-effective. Endoscopic polypectomy can fail in multiple ways. We want to minimize failure by selecting the proper polyps for endoscopic resection, and then choosing and mastering effective techniques. Failure occurs when a polyp cannot be fully resected, when a complication that requires surgical resection occurs, when an endoscopic resection is attempted in a sessile malignant polyp and the patient perforates, which always raises concern about seeding of the peritoneal cavity with tumor, when the patient has lost a follow-up and develops recurrence at the polypectomy site, or if multiple repeated endoscopic procedures are performed to remove the polyp and it still recurs. All persons performing colonoscopy must be trained in polypectomy. It's unacceptable in the current era to perform diagnostic colonoscopy and refer patients with routine polyps to either surgery or to other endoscopists to perform polypectomy. This doesn't mean that a colonoscopist should be able to remove every benign colon polyp endoscopically, or that they should be able to remove every benign polyp which might be endoscopically resectable by another experienced colonoscopist. Colonoscopists should know their own limitations with regard to difficult polypectomy and be willing to refer patients with lesions that are beyond their expertise, either because they are too risky or too technically demanding to successfully complete the polypectomy. Let's talk about preparation for polypectomy. In the informed consent process, the polypectomy complications that we'll discuss with patients are bleeding and perforation, which are both highly dependent on polyp factors. Both bleeding and perforation are increased when polyp size is larger and when polyps are located in the proximal colon. Essentially all perforations and most delayed post polypectomy bleeds result directly from the effects of electrocautery. On the other hand, immediate bleeding is diminished by the use of electrocautery. The use of warfarin, heparin, low molecular weight heparin, and some antiplatelet agents, particularly Plavix, is associated with an increased risk of bleeding. These factors should be considered in estimating the risk of complications from endoscopic resection, particularly in patients who are known to have polyps in the colon prior to colonoscopy. In general, endoscopists who use pure low power coagulation current are more likely to see delayed bleeding, while those who use blended or cutting current are more likely to see immediate bleeds. Counseling the patient regarding the type of bleeding anticipated should it occur may also be appropriate if it's known that large polyps will be removed. If we're going to use electrocautery for a given polyp, we want to make sure to get the effect we expect. Some endoscopists routinely test the cautery by looking for a spark from the tip of the monopolar snare to a grounded object prior to inserting the snare into the patient. I have found modern electrocautery units to be so reliable that I no longer perform that step, but I would certainly not be critical of endoscopists who do perform it. It's important to have a policy in place that ensures that the endoscopist's desired cautery settings are used. In many endoscopy units, the cautery unit is located where it is not easily visually accessible to the endoscopist. The technician should verbally verify that they have visualized the settings at the proper level. A survey of clinical gastroenterologists in the United States shows that as of 2004, there was no standard of medical care with regard to the type of current used for polypectomy. Endoscopists are evenly split between the use of low-power coagulation current versus blended current. I was trained in the use of low-power coagulation current and still use it. On most units, I have the power setting at about 18 watts. The critical factor is that the endoscopist find cautery settings that they find produce an effect that is both reliable and reproducible. Some endoscopists adjust the power setting according to the size and or the location of the polyp. For example, they may use higher power settings on larger or thicker polyps and lower power settings on sacral or proximal colon polyps. Many experts, myself included, rarely vary the power setting regardless of the size or location of the polyp. Prior to any colonoscopy, we should determine the patient's American Society of Anesthesiology risk status for sedation and consider the patient's life expectancy. These issues are also relevant in deciding whether to perform polypectomy. For example, small polyps are unlikely to harm a patient with limited life expectancy. Similarly, we often delay the performance of polypectomy when performing colonoscopy in patients with acute lower GI bleeding since if the bleeding continues, we don't want the differential diagnosis to include a post-polypectomy hemorrhage since that would clinically create diagnostic confusion. We also need to be aware of anticoagulants and antiplatelet agents and determine the need for prophylactic antibiotics. With regard to anticoagulant management, polypectomy is considered to be a high-risk procedure for bleeding. In general, anticoagulation should be reversed prior to polypectomy. However, cold biopsy is considered to be a low-risk procedure for bleeding and cold biopsy can be performed with anticoagulation in the therapeutic range. Since cold biopsy can be used to remove some small polyps, it follows that cold biopsy polypectomy is an acceptable procedure in the patient who is anticoagulated in the therapeutic range. If polypectomy involves the use of electrocautery, then the management of anticoagulants needs to consider the risk of thrombosis when the patient's anticoagulation is reversed. If the patient is considered low-risk for thrombosis, it is reasonable to stop warfarin several days prior to the procedure and resume it after the procedure. In some cases, we may wish to delay starting warfarin for a number of days after the procedure because of concern about a high risk of bleeding. Examples of conditions associated with a low-risk for thrombosis include chronic, stable, deep venous thrombosis on warfarin for more than six months, mechanical heart valves in the aortic position, and atrial fibrillation without mitral valve disease and a dilated left atrium. If there is a high risk for thrombosis, then we can just stop warfarin and begin heparin or low molecular weight heparin, which is often referred to as a bridge. Intravenous heparin is typically discontinued four to six hours prior to beginning the procedure and low molecular weight heparin is typically stopped 12 to 24 hours prior to the procedure. After the procedure, both warfarin and low molecular weight heparin are reinstituted. Examples of high-risk conditions for thrombosis for which bridge therapy must be administered include mechanical heart valves in the mitral position and atrial fibrillation associated with mitral valve disease. There are a number of practices that colonoscopists utilize in the clinical arena, which I would consider to be appropriate and within the standard of medical care. One is for the patient at high risk of thrombosis to undergo a diagnostic procedure on therapeutic anticoagulation. If larger polyps are seen, which occur in only a small minority of patients, the patient can then be rescheduled for a second procedure after reversal of anticoagulation. A second approach is to extend the rules regarding cold forceps in patients who are therapeutically anticoagulated to cold snaring of small polyps. Recently, a third approach has been described in which removal of polyps less than one centimeter in size with electrocautery in therapeutically anticoagulated patients followed by closing the site with one or two endoscopic clips has been shown to be followed by no post-polypectomy bleeding. Finally, many people are anecdotally impressed by the ability of heparin and low molecular weight heparin to induce bleeding in the post-polypectomy period. If it's possible to resume the Coumadin and delay restarting the heparin for a day or two or even more, that is preferable, but obviously this requires discussion with the patient's cardiologist or cardiovascular surgeon. With regard to antiplatelet agents, the ASGE recommends that there is no need to discontinue aspirin or NSAIDs for polypectomy. This may seem controversial since NSAIDs cause bleeding from many other gastrointestinal diseases, but the evidence that they cause post-polypectomy bleeding is inconclusive, so they are allowed at the discretion of the endoscopist. Plavix is a commonly used agent which cardiologists and other specialists may be unwilling to stop for a period of time after stent placement. It may be reasonable under these circumstances to delay polypectomy until the plavix can be stopped. If it's possible to stop it, we typically discontinue it for 5-10 days before the procedure and 10-14 days afterwards. If patients are on both aspirin and plavix, we typically have them continue aspirin since an increased risk of post-polypectomy bleeding with aspirin is not established. In general, prophylactic antibiotics are overused for colonoscopy and polypectomy. Polyplasty with or without polypectomy is considered a low-risk procedure for bacteremia. Antibiotics can be considered at the discretion of the endoscopist for patients considered at high risk of infection, including those with prosthetic heart valves, prior endocarditis, systemic pulmonary shunts, complex cyanotic congenital heart disease, and vascular grafts placed within the last year. Polyp analysis by visual cues in white light and by other new technologies has assumed increasing importance in the past few years. Detailed analysis of polyps, primarily for the purpose of predicting their histology in real time, has been commonly performed in Japan for a number of years. Experienced American endoscopists can accurately estimate the histology of many polyps based on visual cues evident in white light, but detailed analysis of polyps to determine real-time histology has been largely ignored in the U.S. One reason to develop skill in real-time assessment of polyp histology is that we increasingly see more emphasis on high adenoma detection rates. As endoscopists become more and more sensitive in the detection of adenomas, they often also detect more non-adenomatous polyps, including small hyperplastic polyps in the distal colon that have very limited clinical significance, but which result in cost to patients and insurers when they are removed. This section will serve as an introduction to polyp analysis, focusing on technologies that are most likely to become available on a widespread basis. We'll first discuss classification of polyp shape. In the U.S., polyps are usually classified as pedunculated or sessile. At this time, many electronic report generating systems only have pedunculated and sessile as options for shape description. To get up to date with new terminology, we need to recognize that sessile lesions have now been subdivided into sessile and flat, a very small subset of lesions are actually depressed. We need to define what flat means, but a reasonable first question is, who cares about distinctions between flat and depressed lesions on the one hand and sessile lesions on the other? Actually, there are a couple of reasons to make this distinction. First, there's a substantial amount of data indicating that flat and depressed lesions are more likely to be missed during white light endoscopy. Therefore, special attention and perhaps new technologies are needed to reliably detect them. For example, there's a body of literature suggesting that pan-colonic chromoendoscopy, which means spraying dye on the entire surface of the colon, enhances the detection of adenomas. It's very difficult to conclude whether the benefit is almost entirely for the detection of tiny adenomas with low-grade dysplasia or whether it extends to adenomas with high-grade dysplasia. In addition, pan-colonic chromoendoscopy is not very practical, particularly in the United States, because it's time-consuming. Similarly, there's interest in the use of narrow-band imaging or shining blue light on the colon as a way to detect more adenomas. Finally, there are studies being done with autofluorescence, which can highlight adenomas polyps and therefore potentially improve their detection. My own opinion is that the benefits of these techniques for routine colonoscopy remain uncertain at this time. New techniques to look at the colon have to be substantially effective in improving the detection of flat and depressed lesions, and at the same time, they have to be practical to apply. The benefits of these techniques are very likely to be operator-dependent. That is, an endoscopist who is already highly successful with very high adenoma detections in white light is much less likely to benefit from adjunctive measures of this type. It's certainly possible that these technologies could reduce the variability between endoscopists and the detection rate of adenomas. A second reason why flat and depressed lesions deserve attention is that they're more likely to have high-grade dysplasia or invasive cancer compared to sessile or pedunculated polyps of similar size. I want to emphasize that the absolute risk of high-grade dysplasia and invasive cancer among all flat lesions in the colon is still very small. However, the relative risk is likely to be increased compared to sessile and pedunculated lesions. All in all, we should conclude that American endoscopists need to understand what flat and depressed lesions are and that they'll need to be looking carefully in the colon to detect these lesions with white light. It's too early to say what, if any, additional technology is needed and in what patients it would be needed to assist in the detection of flat and depressed lesions. What does flat mean? Unfortunately, the literature contains different definitions of flat and depressed. The original definition proposed by Japanese investigators was of a lesion that was fairly small, less than 1 to 1.5 centimeters in size, with a histologic height that was less than twice that of the surrounding normal mucosa. I like this definition from the standpoint that it describes a group of lesions that are almost certainly more difficult to recognize in white light. Of course, it's not a useful definition endoscopically because it requires removal and histology in order to define it. Another definition is a lesion that is more than twice as wide as it is high, but this definition includes many lesions that are quite obvious in white light. A third definition and a standardized terminology is provided by the Paris classification. In the Paris classification, type 1 lesions are pedunculated or sessile and type 2 lesions are flat or depressed. We can distinguish type 1 lesions from type 2 because they project into the lumen more than the width of a 2.5 millimeter biopsy forceps. Type 2 lesions project into the lumen less than 2.5 millimeters. Two A lesions are elevated and flat. Two B lesions are perfectly flat with no elevation. In clinical practice, one S lesions are considerably more common than one P, and two A lesions are much more common than any other type of flat or type 2 lesions. Therefore, the great majority of polyps encountered in clinical colonoscopy in the United States are one S or two A followed by one P and then the remainder of the type 2 lesions. Type 2C lesions as well as 2A plus 2C and 2C plus 2A are quite rare and are definitely the most worrisome lesions with regard to high-grade dysplasia and invasive cancer compared to the other shapes. Here are examples of one S polyps. In the next slide, we see a 2A polyp on the left and a 2B polyp on the right. Both of these polyps are seen in blue light or narrow band imaging. True 2B polyps, such as that seen on the right, are quite rare. 2A are flat lesions and are almost invariably visible with careful white light colonoscopy, but careful examination in white light is required to avoid overlooking them. A reasonable question to ask next is should all detected mucosally based polyps be removed? Most American endoscopists would say yes for all adenomas regardless of size. There also are hyperplastic polyps in the proximal colon, particularly if they are large, that have molecular profiles similar to a group of proximal colon cancers in that they are often microsatellite unstable and may have BRAF mutations in them. These polyps are in some instances precursors of serrated adenomas. Finally, larger Putz-Jager and Juvenile polyps may develop adenomatous degeneration and therefore should be removed from patients. On the other hand, small distal colon hyperplastic polyps, inflammatory polyps, pseudopolyps in inflammatory bowel disease, and mucosal polyps, which are normal mucosal tags, do not generally need to be removed. Having made this distinction between polyps that should be removed and those that need not be removed, we can see that polyp shape is not very important with regard to these distinctions, which really are based on histology rather than shape. In short, the shape classification is less important than real-time histologic differentiation of polyps. The main value of the shape classification is to highlight the importance of careful examination for flat and depressed lesions and in the long run to understand whether new technologies that enhance detection of flat lesions are necessary. Right now in clinical practice, a common approach is to remove all polyps seen unless there are multiple polyps in the rectum and sigmoid that appear to be hyperplastic, in which case those polyps are just sampled by biopsies. This begs the question of whether new technologies might allow reliable determination of histology in real-time so that resection of harmless polyps might be avoided. Before we consider that question, we should note that certainly there are features seen with white light that can be predictive of histology. For example, distal colon hyperplastic polyps, small sessile lesions in the distal colon, sometimes with relatively straight blood vessels running across them, these lesions are very typically hyperplastic. Proximal colon hyperplastic polyps can often be recognized by their typical mucus covering and because with manipulation during snare polypectomy, they readily deform and appear to be redundant mucosa. Such lesions are often hyperplastic polyps or serrated adenomas. Here we see proximal colon hyperplastic polyps in narrow band imaging in the upper left, white light in the upper right, and high definition after dye spraying in the lower right. Here's an example of a large proximal colon hyperplastic polyp. This one doesn't have much mucus on it, but it does show that when you snare the polyp, it develops folds or wrinkles. The polyp is easily deformed and acts like redundant mucosa. The second polyp is a large sessile serrated polyp in the proximal colon. Note the mucus on the surface of this polyp. Red or pink-headed pedunculated polyps, like the ones in these photographs, are typically adenomas, though juvenile polyps and putschiager polyps can have this appearance also. Polyps with exudate on the surface are typically inflammatory, though juvenile polyps may also have exudate. Here we see a slightly pedunculated polyp covered with exudate, which is typical of inflammatory polyps. Here's a pedunculated red-headed polyp with just a few foci of exudate. This lesion was also an inflammatory polyp. This exudate is highly predictive of inflammatory polyps, although certainly much larger adenomas, particularly with high-grade dysplasia and cancers, may also have exudate on them. Pseudodepression or shallow depressions in sessile polyps are characteristic of adenomas. Ulceration on the surface of an otherwise obvious adenoma of significant size suggests the presence of cancer or high-grade dysplasia. This polyp with central depression had high-grade dysplasia. This cecal polyp has a central depression suggesting high-grade dysplasia or cancer. In the top right, the polyp can be seen to be readily lifted and removed, and pathologic examination confirmed high-grade dysplasia. This slide shows a right colon polyp with mild central ulceration in white light on the left and blue light on the right. This polyp was a stage 1 adenocarcinoma. This sigmoid polyp has severe central ulceration, but has been lifted on the left and removed in a single piece on the right. Severe ulceration is highly predictive of cancer, and pathologic examination of this lesion showed a stage 1 colorectal cancer. This slide summarizes these white light features that predict histology. Unfortunately, white light clues are not sufficiently accurate to determine histology in real-time in many instances and additional technology is often needed to determine real-time histology. Much of the literature on real-time histology focuses on pit pattern analysis. Pit analysis has typically been performed with chromoendoscopy and high-magnification colonoscopes, although it can be performed with chromoendoscopy and high-definition colonoscopes. Narrowband imaging can facilitate real-time histology because blue light penetrates only superficially into the mucosa and the reflected light provides greater mucosal detail than is seen with white light. Professor Kudo in Japan described the correlation between the appearance of colonic pits and histology. Type I pits are small, round pits evenly distributed across the polyp surface. Type II pits are larger, stellate or asteroid-shaped pits, also dispersed evenly across the polyp surface. Type I and II pits indicate hyperplastic histology. Adenomas typically have type III or IV pits. 3S pits are tiny, tubular, round pits that are smaller than the normal type I pits, and 3L pits are elongated. Type IV pits are similar to 3L but include branching. Type 3L and type IV pits often coexist on the same polyp. In general, a polyp should be classified as hyperplastic or adenomatous depending on the worst grade of pits evident. Thus, polyps with some type I pits and some 3L pits would be classified as an adenoma. Again, types I and II indicate hyperplastic histology, and types III and IV are adenomas. Type V and type VI will not be reviewed here as they are used primarily to estimate the likelihood of cancer and depth of invasion. The principal distinction for American endoscopists is between type I and II pits, which will not require removal if they are small lesions that are located in the distal colon, and polyps with type III and IV pits, which should be removed. We will focus here on still photographs since interpretation can often be best done after focusing the endoscope on the pits and freezing the image. These photographs are taken again in blue light or so-called narrow band imaging. Note the evenly spaced pattern of very small, round pits. They are highlighted in the two polyps on the left because of some dark coloration from congestion. These polyps are hyperplastic. These polyps demonstrate pits that are slightly larger and not perfectly round, but they are evenly spaced across the surface of the polyp. These are type II pits indicating hyperplastic histology. Here we see polyps with high definition and chromoendoscopy, showing type I pits in the top two photos and type II pits in the bottom photos. These polyps are seen in blue light on the upper left, white light in the upper right, with chromoendoscopy and high definition on the lower left, and blue light on the lower right. Elongated grooves on the surface indicate the presence of 3L pits, the most common pit pattern seen in adenomas. These photographs show 3L and some type IV pits photographed with chromoendoscopy and high magnification. The pit pattern is more obvious with high magnification. High magnification and chromoendoscopy is a highly reliable method of pit pattern analysis. The simplest technique to apply dye to evaluate a polyp is to use indigo carmine, which comes as a 0.8% solution, dilute it with water down to 0.2 to 0.4%, put the diluted indigo carmine in a syringe, put air in the syringe, invert the syringe, and use the air column to force the dye down the scope. To demonstrate this, we are looking at a mucus-covered polyp in the cecum, and we're washing the mucus off. Now we'll spray the polyp with indigo carmine. We draw up the air column, invert the syringe, and push the dye down the scope onto the polyp. Next we are zooming in with a magnifying scope, which as I've said already is not widely available, but which here demonstrates large stellate pits typical of a hyperplastic polyp. Even though this polyp is hyperplastic, because it's larger and located in the proximal colon, we still should remove it. Therefore, the value of pit pattern analysis, in my opinion, is primarily for identifying small distal colon hyperplastic polyps, which generally do not need removal. Here's an enlarged photograph taken in blue light with a high-definition colonoscope of a sessile adenoma. Notice the variation in the size of the pits, another feature of adenomas, as well as the numerous elongated pits. Lack of uniformity in the size and shape of pits is also characteristic of adenomas. Here's a tiny, flat, two-way adenoma showing elongated pits on the edges of the polyp, with variation in the size of pits between the middle and edge. These are 3L pits. Here's the surface of a pedunculated polyp at about 70 times magnification using an electronic zoom and a high-definition colonoscope. Notice that there are both 3L pits and branched, or type 4 pits. This polyp is an adenoma. This flat, two-way polyp shows elongated pits on the perimeter of the polyp, and the pits are much smaller in the center portion. The presence of 3L pits and the variation in pit size indicates that this is an adenoma. The tiny brown lines on the surface of the polyp represent microcapillaries. The large number of microcapillaries and the tufting that are well seen with blue light or narrowband imaging are also characteristic of adenomas. Autofluorescence is not widely available, but makes use of the fluorescence pattern of polyps. Adenomas in the systems currently under development appear red or pink compared to hyperplastic polyps, which have a different fluorescence pattern, which is similar to that of normal colonic mucosa. Confocal laser microscopy is another technique which allows determination of histology in real time. These photographs show the normal colonic mucosa, the histology in the lower left, and on the right, the confocal laser microscopic image showing the actual histologic pattern of the glands in the normal mucosa. This technique can also be used to differentiate hyperplastic from adenominous histology when it's used in the evaluation of colon polyps. It's quite possible at this time to practice colonoscopy without paying attention to real-time histology, but in the future, this is probably going to become increasingly important. We're going to see that our instruments are going to be better and better and allow us to be more and more sensitive in the detection of polyploid lesions. Some of these lesions aren't very important, and their removal just increased costs as well as increasing the risk of colonoscopy to our patients. So I think it's time to start thinking about learning one of these techniques that will allow us to determine real-time histology. And in reality, they're all relatively straightforward. How available they are is going to be dependent on what type of endoscope technology you have available to you, but I'd encourage you to follow this story closely and to start to learn the techniques and incorporate them into your regular practice. We'll be covering many technical details that pertain to safety in the discussion of specific polypectomy techniques in other portions of the DVD. However, I would like here to summarize some general principles with regard to safety as we know it from the currently available literature. Obviously, these conclusions are subject to change as new information becomes available. With regard to general principles, perforations during polypectomy result entirely from the use of electrocautery. That is, thermal injury either allows an immediate deep injury to the muscularis propria or thermal injury damages the muscularis propria so that it later undergoes necrosis and perforates in a delayed fashion. Without the use of electrocautery, it is extremely difficult to mechanically transect the muscularis propria with a wire snare. Similarly, delayed postpolypectomy bleeding most commonly results from electrocautery injury to submucosal vessels. As discussed earlier, the types of current chosen, which are a matter of personal preference of the endoscopist, cause trends in the type of bleeding that will occur. Thus, low-power coagulation current tends to be associated with very little immediate bleeding but a greater risk of delayed bleeding, and blended or cutting current results in a greater tendency toward immediate bleeding. Many of the principal teachers of colonoscopy and polypectomy over the past two decades, myself included, have personally used pure low-power coagulation current to perform polypectomy, and the polypectomy shown in the DVD used that current. However, advocates of blended or cutting current make a valid argument that immediate bleeding is preferable to delayed bleeding in the hands of a skilled endoscopist because immediate bleeding can be managed during the endoscopic procedure, whereas delayed bleeding will typically result in the patient being required to return to the hospital for treatment. With regards to two of our goals of providing effective removal of polyp and avoiding complications, cold techniques, including forceps and snaring, are superior with regard to prevention of complications, although this has not been proven in a randomized trial. Forceps techniques tend to be less effective than snaring techniques for complete resection of the polyp, although this may not be the case for many of the 1 to 3 millimeter polyps that are now visible with high-resolution and high-definition colonoscopes. These issues are of particular importance with regard to the removal of small polyps, which we would like to remove effectively, but which in the overwhelming majority of cases are never going to harm the patient, and therefore it's important that we attempt to remove them without complication. This tends to make techniques such as cold forceps removal of 1 to 3 millimeter polyps, particularly with large capacity or jumbo forceps, very attractive, and it also makes the use of cold snaring attractive. These results of a survey of clinical gastroenterologists in the United States indicate that there is no standardized method of removing polyps less than a centimeter in size, though forceps techniques predominate in the 1 to 3 millimeter size range. Hot snaring predominates by a small margin in the 4 to 6 millimeter range, and hot snaring is the clear preference of gastroenterologists in the 7 to 9 millimeter range. My personal recommendation, which is made in the interest of optimizing the balance of safety and effectiveness, is that cold forceps and cold snaring should predominate for 1 to 3 millimeter polyps, and cold snaring should play a significant role in 4 to 6 millimeter polyps, particularly those that are relatively flat or have a 2A shape. To summarize available data from clinical trials, cold techniques appear safer for the removal of small polyps. Detachable snares have been shown in two randomized trials to be effective in the prevention of both immediate and delayed bleeding, and they can be considered for thick stalked or large pedunculated polyps. I will admit to using them relatively infrequently and personally prefer to place clips on any polypectomy stalk or site for which I believe there is a high risk of delayed bleeding. Epinephrine injection has been shown to prevent immediate bleeding from both pedunculated and sessile polyps in randomized trials. I do not believe that the standard of medical care requires epinephrine injection for either pedunculated or sessile polyps. Again, a decision regarding the use of epinephrine might depend on the type of current used. In my own case, using pure low-power coagulation current, it is quite rare for me to see immediate bleeding, so I don't use prophylactic epinephrine. It could be more advantageous in patients whose physicians use blended or cutting current. Clipping polypectomy sites has not yet been convincingly proven to prevent bleeding. It was ineffective in a trial which included a large number of polyps at very low risk of bleeding. There has not yet been an adequate randomized trial in high-risk polyps. As I mentioned, many endoscopists, myself included, use clipping for high-risk polyps when feasible. Finally, submucosal injection is now widely practiced and has been shown to prevent deep injury, in other words, injury to the muscularis propria, in animal models. In these animal models, there was the use of electrocautery snaring and the argon plasma coagulator. However, it has not been proven to prevent perforation in clinical trials in humans, and in fact, no randomized trial on this topic is available. The details of application of these tools are discussed elsewhere in the DVD. In this section, we'll review the technical aspects of polypectomy. The four techniques that we'll review are cold forceps, hot forceps, cold snaring, and hot snaring. General principles of cold forceps are that we would like to engulf the polyp in one piece. It is preferable to not piecemeal a polyp with cold forceps because there is an increased risk of leaving residual polyp. The use of cold forceps can be appropriate for 1 to 4 millimeter polyps depending on the shape and bulk of the polyp and the size of the forceps that are used. Clearly, large capacity forceps can remove a larger polyp in toto in one piece. Here we see an indigo carmine stain colon in which we're using a large capacity needle forceps to engulf small polyps and simply pull them off. The advantages of the cold forceps technique include that it's devoid of complications because we're producing only a mucosal injury, and also it's very efficient because it's easier to place forceps on small lesions than it is to place snares on them. And also you'll notice that these lesions are so flat that they would be very difficult to snare. In addition, this technique can be performed in patients who are therapeutically anticoagulated, and the risk of bleeding is extremely minimal to none. Hot forceps can also be used to treat small polyps. On an anecdotal note, I never use hot forceps and haven't for many years. In my opinion, hot forceps are risky because the cautery burn associated with them is not always predictable, and they also are frequently ineffective in destroying polyps. However, as demonstrated in the previously shown survey, it's completely within the standard of medical care to use hot forceps in the removal of small polyps. According to an ASGE guideline, hot forceps are appropriate for polyps less than or equal to 5 millimeters in size. They should not be used for larger polyps. The proper technique with hot forceps is to grasp the tip of the polyp, tent or lift the polyp into the lumen, and then apply cautery. The burn will spread down the polyp in the so-called Mount Fuji effect. After cautery has been applied, the portion of the polyp in the biopsy forceps is mechanically pulled off and sent for pathologic examination. You'll notice that we are removing very small polyps here from the distal colon. The larger the polyp on which hot forceps are used, the more likely they will be ineffective. This is because there is no way to be certain that the central portion of the polyp has been effectively eradicated. The repeated use of hot forceps to biopsy or attempt destruction of larger sessile or flat polyps is incorrect, and there are no data in the literature suggesting that this technique is effective. Hot forceps are often suggested to be associated with an increased risk of complications, but the evidence to support that contention is anecdotal. However, there is no question that electrocautery causes essentially all of the complications in the removal of small polyps, and thus the use of electrocautery should be minimized in the removal of these small lesions. This slide summarizes the features of hot forceps polypectomy that we've discussed. Cold snaring is an effective technique for polyps in the range of 1 to 7 millimeters in size in the literature. The size of polyps that can be removed with cold snares varies with the shape of the polyp. For flat polyps, cold snaring can be appropriate in my practice for polyps up to 7 and even 10 millimeters in size. I occasionally cold piecemeal flat polyps in this size range. For polyps that are bulkier or dome-shaped, cold snaring is appropriate for polyps up to 4 to 5 millimeters in size. For pedunculated polyps, cold snaring can be considered again for polyps up to 4 to 5 millimeters, depending on how bulky the polyp head is. Now let's proceed to discuss snaring, but first a word about snares. There are lots of personal preference issues with regard to snares, and my comments to some extent reflect my own personal preferences, but I think a few issues deserve mention. First, most of the polyps we remove are very small. Diminutive snares, such as the one depicted here, are the easiest and most efficient to use for these small polyps. When resecting very large sessile polyps, it makes sense to start with large snares, but at the end of the polypectomy, switching to one of these small snares can be useful for cleaning up small areas of residual polyp. The shape of the snare can be important in improving the efficiency of resecting large polyps. For example, notice that the large oval snare on the left has a much more open shape than the one on the right, and I find that that very open shape is a distinct advantage. Finally, various specialty snares are available. Examples include needle-tip snares, and these snares can be anchored on the proximal side of the polyp using the needle, allowing superior positioning as well as manipulation of the snare shape by pushing against the anchor point. For resecting very flat polyps and flat portions of polyps, so-called spiral snares, Cold snaring has been shown to be effective in polyp removal. I usually try to remove a thin strip of normal mucosa around the polyp, a technique that is not recommended with electrocautery use. Cold snaring is devoid of bleeding complications in patients with normal clotting, and it is not recommended with electrocautery use. Cold snaring is not recommended with electrocautery use. Cold snaring is devoid of bleeding complications in patients with normal clotting. Immediate bleeding is typical with cold snaring, but is of no clinical significance. The technique is to grasp the tissue around the polyp, including a bit of normal tissue, and then mechanically transect it. Tenting is not necessary with cold snaring, since there is no risk of injury to the deep layers of the colon wall. I currently use this technique for about 80% of the polyps that I remove during colonoscopy. Here you see the removal of a sessile polyp. We can grasp some normal tissue at the base and cut it off. It will stay in place as long as we don't tent. And after removal, we move the biopsy channel up to the site and suck the polyp back into a trap. A small amount of immediate bleeding is of no consequence because these polyps don't have large vessels. We're simply cutting through capillaries, and capillary bleeding will invariably stop spontaneously. I repeat, the amount of bleeding you're seeing with these polyps is of no significance. When we take off a very flat polyp, it's useful to push the snare tip up against the colon wall to help entrap the polyp in a small rim of tissue around it. Then we simply close the snare and cut the polyp off. Almost invariably, the polyp will stay right on the site, and we can then move up and suck it right back into the trap. Here's a good example of taking a strip of normal mucosa off around a small polyp. This technique can be performed repeatedly with really no concern about complications. This slide summarizes a number of the important aspects of cold snaring that we've discussed. The optimal positioning of polyps for polypeptomy is in the lower right endoscopic field. Here is a polyp that is in the upper endoscopic field. Polyps in this location, or in the upper left endoscopic field, can be difficult to snare. One way to resolve this is to rotate the scope by a combination of torquing the scope and turning the right-left control, which will position the polyp in the lower right endoscopic field, where the accessories exit from the scope, as shown in this cold scenario. The principles of hot snaring are as follows. First, it is appropriate for any polyp, but again, cautery is often not needed for diminutive polyps. The technique is to grasp the polyp at its edges and to avoid grasping normal tissue. The polyp is then lifted or tented into the lumen. The lumen is deflated to thicken the wall. Cautery is applied, and the base of the polyp is mechanically transected. Here we see a pedunculated polyp that we're going to grasp by the stalk of the polyp and then lift or tent into the lumen. Please notice that we see a white cautery burn on the polyp before we begin the actual mechanical transection. Thus, we instruct the assistant to hold off on transecting the polyp until we see that white coagulum. Now we've got a sessile polyp about a centimeter in size. Notice that we're grasping right at the edges of the polyp, which is different from what we discussed with cold snaring. Again, before we begin the mechanical transection, we want to see a little bit of coagulum near the snare. That's the whitish color. And then we'll begin the mechanical transection. And then we're going to inspect the polypectomy site. Some people prefer to photograph the polypectomy site, but I don't think the standard of care requires that. Here's another pedunculated polyp, which we've grasped. And we are, again, lifting into the lumen, applying a bit of burn, seeing the coagulum as the snare closes. And then we're cheese wiring through that desiccated tissue in the stalk of the polyp. We then retrieve the polyp and inspect the site. Here's a slightly larger polyp, but the principles of transection will remain the same. This polyp has very little stalk. And sometimes we can't see if we have the whole polyp. So after transection, there may be a little bit of residual polyp, as there is in this instance. And we certainly want to remove that. So we're just going to close on that and apply the same principles. Now, we're not lifting very well here. But in general, lifting is good, and also a bit of deflation of the lumen to thicken up the wall. Now we're seeing some small polyps in the cecum that we're going to remove by electrocautery using the snare technique. And notice how much we've lifted these polyps, pulled on them, or tented. And we're also deflating the lumen in order to thicken up the cecum wall. Here in this polypectomy, you see a little bit of movement of the polyp, which we'll discuss in the removal of larger pedunculated polyps. I don't think it's real important to move the polyp unless it's large enough to be touching the opposite wall. And even then, there's no proof that that's really important, but it's often done. Now, notice that we're using electrocautery here on smaller polyps that are pedunculated or dome-shaped. I mentioned that in the 4 to 6 millimeter range, I often use cold snaring. But if a polyp is quite dome-shaped, or in this case, small pedunculated polyps, then I think oftentimes it's still good to use electrocautery, because they can have slightly bigger vessels in them, and their transection is cleaner. We can use electrocautery in the removal of sessile polyps. And notice that it's important for efficiency to open the snare in the optimal position. So here, we're laying out the snare tip with the tip right on the upper edge of this polyp, so that we can then very simply lower the snare and put the fork of the snare right into the edge of this polyp that's closest to us. So where we position the snare before we open is going to significantly increase the efficiency. Once we've closed down, we're going to deflate the lumen and then move this polyp off to the left somewhat, in other words, toward the center of the lumen, again, to try to thicken up the wall. And we're actually pulling it a bit towards us again. And then always, we're going to inspect the site for residual polyp. And there is a little bit of residual polyp, so we're going to grasp that and then apply the same principles. We're lifting, tenting toward the center of the polyp. Now, we're not injecting this polyp. And I'm not a stickler about injecting every sessile polyp. And very commonly, we remove sessile polyps less than 2 centimeters without injection, although we'll be covering injection techniques later in detail. Here's another small polyp seen first in blue light. Now, with white light, you can see that it has some 3L pits on the surface. Again, we're tenting, applying a bit of cautery, seeing the coagulum, and then doing the mechanical transection. Notice, again, that the lumen is deflated. We're seeing here another polyp which has some 3L pits. We're seeing it first in blue light and taking a photograph. I typically prefer to actually do polypectomies in white light, but it's fine to do the inspection for pits with blue light because it can facilitate that, although we may see them in white light. Same technique, deflate, lift the polyp into the center of the lumen. Oftentimes, the polyp stays right on the site, and then we can transect it. Now, here's a larger polyp that we're going to piecemeal out without injection. Our principles are the same. We're going to close. We open the snare over the polyp, then move the snare down around the base, close down. We're going to deflate the lumen, and we are then applying electrocautery. And in this instance, then we see that there is some residual polyp. Piecemealing is going to follow the same principles that hot snaring does in the removal of smaller polyps. That is, as we grasp each piece, we get right around the edges of the polyp. Then as we close down, we also, after closing, we're going to deflate the lumen and then lift that polyp into the center to thicken up the wall and protect the wall. We always have in mind trying to protect the wall as we apply electrocautery. We want to try to remove, then, the entire polyp in one piece. You'll notice that many times as we pinch these polyps, we can see the pit pattern quite well on the surface. We've got a little bit of polyp left on the backside that we need to touch up. We want to be very careful to just simply get the polyp and not get normal tissue in the snare, and we do that by inspection. If there's any resistance, then we have to re-inspect. Here's the polypectomy site, and we're done.

colonoscopic polypectomy

preparation

visual analysis of polyps

safety issues

techniques

high-risk polypectomy

complications

post-polypectomy surveillance

colorectal cancer