It’s hard to say precisely how common flat polyps are because results are subject to variation between examiners and techniques. But doctors performing colonoscopies are finding them more easily and treating them more successfully as techniques improve.
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Today, the incidence of flat polyps hovers around 10 percent. Still, they too often go undetected and unrecognized simply because they are, literally, flat, says colorectal surgeon Emre Gorgun, MD.
“Endoscopists and surgeons may not consider flat polyps common at all, but in reality, if you recognize them early on, you will see how common they are,” Dr. Gorgun says.
“They tend to be under-recognized by inexperienced endoscopists or people untrained in removing that specific polyp. Usually endoscopists aren’t trained to notice them, and their eyes are more used to recognizing lesions emerging from the surface level.”
Well-trained doctor is key
There are some endoscopists, on the other hand, who recognize flat polyps but are not necessarily comfortable with treating them. For these cases, they will give patients a referral.
But the only step patients can take to ensure detection is to make sure they have a skilled endoscopist when they go in for a colonoscopy in the first place, Dr. Gorgun says. That’s especially important because flat polyps can grow and, eventually become cancerous, he says.
“Patients definitely should pick someone known for screening endoscopy as well as interventional endoscopy,” Dr. Gorgun says, adding that most Cleveland Clinic endoscopists are well trained in this area.
“Common endoscopists may not be skilled to recognize those flat polyps. It’s better to have a colonoscopy done at a good facility, which has physicians on board capable of recognizing and removing them.”
ESD and other removal techniques
A couple years ago, Dr. Gorgun helped pioneer an approach to remove flat polyps called endoscopic submucosal dissection (ESD). He’s still one of just a few physicians who perform this technique, which he learned in Tokyo where it’s more commonly performed.
Typical colonoscopy involves tying a snare around the polyp and cauterizing and cutting the tissue off, but the snaring technique doesn’t work with flat polyps, he says.
Instead, with ESD, endoscopists dissect the polyp, using a solution to lift, cut and burn the unwanted tissue, or sometimes they even create a tunnel underneath it to take it out in one piece.
“This allows you to remove these polyps oncologically, without destroying the tissue around them and without having to take out the whole colon,” Dr. Gorgun says.
Other techniques for removing polyps include:
- Snare polypectomy, the classic polyp removal technique that most endoscopists use.
- Endoscopic mucosal resection (EMR), which combines the snaring technique with a solution, as in ESD.
- Endoscopic full-thickness resection (EFTR), which involves removing the colonic wall that contains the polyp and closing the opening internally, with clips, so there’s no need for a bowel resection.