A small colonic TA+LGD as visualised by Pentax's 4 different optical modes. WHAT SIZE SNARE TO USE? a) 10mm b) 15mm c) 20mm d) 25mm WHERE TO PLACE THE SNARE (top right image)? a) at 'a' b) at 'b' c) at 'c' explanation
Even with a small polypectomy such as this there are things to discuss. FIRST, select a snare which fits nicely around the polyp. In this case, a 10mm snare is probably optimal. A snare which fits snuggly, is less likely to capture a fold of mucosa somewhere behind the polyp. In this case, you could probably see if this is happening but particularly in an angulated and spastic sigmoid, capturing too much mucosa can be an issue. Of course, if I have already used a larger snare elsewhere in the colon, I would consider using that snare again. I do try to keep costs down if possible 😳 ! SECOND, place the snare in the middle of the stalk (at b). Giving a small amount of stalk for the pathologists to confirm that the polyp has been completely removed will avoid a subsequent 'site-check'. Conversely, placing the snare too close to the base may cause two problems: a) more heat damage is imparted onto the nearby colonic wall and b) you no longer have a stump to re-capture if there is bleeding. Which leads me on to the THIRD point; 'haemostasis'. Bleeding is the main concern for us all when we do polypectomy, EMR and even ESD. My approach is as follows: ■ Anticipate bleeding! It's more likely with large polyps or polyps with thick stalks. Consider what you will do if there is bleeding. For a stalked polyp, the best option is to re-snare the polyp. For a large sessile polyp, a haemostatic forceps is usually the best bet. Ask your assistant to have the forceps immediately available (still in it's sterile packaging). By the way, I usually use a 'hot biopsy forceps' because they cost £10 compared to the £200 for a fancy haemostatic forceps. ■ Prevention. Most admit that I never place a clip on the stalk before cutting it. This is because the current can easily travel down the clips tail and cause a burn at some unexpected place. However, I often pre-inject a thick stalks and large pedunculated polyps with dilute adrenaline. It will buy me a valuable minute of 'gentle oozing' from the vessel before the floodgates open. At ESD, you will of course coagulate the vessels as they appear in your dissection field. A large sessile 4cm polyp can be removed by single fragment EMR (there are snares large enough) but you will of course have to deal with several bleeding vessels once the polyp has come off. Of course, at ESD you can deal with the vessels one-by-one and this may be preferable than going for the 'quick option' of an EMR. Under the heading "Prevention", I should also mention that I advice my assistant on how many seconds I think it will take to cut the polyp. I also tell them that once they see the stalk being cut by the snare, they should ease off and stop closing the handle. The 'inertia' in the system will cut the rest of the polyp at the appropriate speed. After all, the vessels are in the CENTRE of the stalk and it's the last few seconds of cutting which deals with them! You don't want to rush this bit!!! For this reason, I am not a fan of 'pre-coagulating' the stalk by pressing on the blue pedal first. This cooks the harmless outside of the stalk but leaves the important centre intact. If anything one should do the opposite! Actually, with modern diathermy you don't need to concern yourself as the clever machines deliver mainly 'cut' at the beginning (when the resistance in the electrical circuit is greater) and then moves to short pulses of 'coagulation' and 'pause' (to allow tissues to cool down) as the electrical resistance drops as the stalk is cut. ■ Clipping. This deserves it's own 'heading'. I almost always place clips unless it's cold snaring a small polyp in a patient who is not taking blood thinners. Of course, I work in a part of the world when I don't need to worry about whether the patient can actually afford the clips 🙂 . When you feel exhausted after a 60 minute resection, it's easy to leave the clips out. It would be a mistake! Clipping reduces the risk of both late bleeding, the post-polypectomy syndrome and late perforations! This polyp was found in the transverse colon in a patient with long-standing ulcerative colitis. WHAT WOULD YOU DO NEXT? a) retrieve the polyp and look for other polyps b) obtain 4 samples from the nearby mucosa c) apply APC to the EMR edges d) tidy the edges up with a cold snare e) apply clips Explanation
That hole isn't right! More often than not, this is how a perforation looks immediately after polypectomy. As a beginner you may think that you should be able to see the peritoneum but that would be the exception. Must admit that I was surprised to see this perforation. The lift seemed to be good and I didn't use a 'super-stiff' snare. Perhaps it had something to do with the fact that the patient had colitis? Because the 'cutting' should have taken 6-7 seconds but took about 12 seconds, I did expect 'trouble' and had started to suck air out of the colon before the snare cut through completely. Fortunately, the colonic lumen is not deflating as the perforation is close to the omental reflection. We will have a few minutes before the patient starts to become uncomfortable. Spend those minutes well !!! I applied 10 clips. The colon was clean and I was confident that there was no peritoneal contamination. Of course, this is one of the reasons why your polypectomy site should be as dry and clean as possible before you step on that yellow pedal! There was no pain and after a couple of hours in recovery and I discharged the patient with verbal and written instructions to return to A&E if pain developed later. The patient was fine. Can I reassure you that every patient will be fine after closing a perforation by clips? Of course not! You need to follow your instincts and your local protocols and of course be able to defend your decisions. Naturally, the particulars of the actual patient is very important. For example, an elderly patient or someone living alone should probably not be discharged. After all, sepsis can develop quickly and the patient may soon be in no fit shape to call for help. This polyp was found in the sigmoid colon. WHAT IS THE LIKELY AETIOLOGY OF THE POLYP? a) hyperplastic polyp b) adenomatous polyp c) malignant polyp Explanation
The sigmoid colon is the most 'powerful' part of the colon developing the force needed to go to the toilet. Presumably this is the reason why diverticular disease first develop in the sigmoid. The force can also create pseudo-polyps from patches of inflammation which I presume gets tugged along with each peristaltic wave. Even adenomatous polyps which develop here usually become traumatised. The end result is that this is the most difficult part of the colon to assess polyps. This particular lesion had been unchanged for several years but it spooked an endoscopist sufficiently to refer it for an EMR. Samples had indicated that it was a hyperplastic polyp only (correct answer was A). Fifteen years ago, the idea of subjecting the patient to an endoscopic resection for a lesion not recognised to be linked with cancer could have been criticised (if there was a complication). However, nowadays it is recognised that SSL's (hyperplastic polyps with L or T-shaped crypts etc) are 'fair game'. The truth is that it's probably impossible to tell a 'simple' hyperplastic polyp apart from a 'sessile serrated lesion' and pathologists are increasingly called all these 'serrated lesions'. For this reason, I go by the size. If the 'serrated lesion' is 10mm or larger, I usually remove it. In this particular 'polyp', most is actually just a swollen fold. The serrated area is situated at the very tip of the fold. When I see this, I don't go overboard placing the snare a long way down the 'pseudo-stalk'. If you did, you will find that it's taking a long time to cut through all that healthy sigmoid mucosal fold and you run the risk of a late perforation. Instead, I just caught the tip of the fold and ask my assistant to close the snare as quickly as possible whilst it was cut on a blend current (yellow pedal). Of course, you don't need to worry about large vessels in serrated polyps. |
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