Polyp removal and EMR in Sydney

Why polyps are removed

Every polyp found at colonoscopy is assessed for what it is and how much risk it carries, and the precancerous types are taken out. Size and shape change the job rather than the reasoning. A lesion of 20 mm or more, or one that spreads flat across the bowel wall rather than sitting on a stalk, cannot simply be snared off, and the larger it is the more likely it already contains an area further along towards cancer. Those are the polyps this page is about.

Small polyps are removed with a small wire loop or forceps during the same colonoscopy in which they are found. This adds little time and most people are unaware it has happened until they are told afterwards.

Large and flat polyps: EMR

Polyps 2 cm or larger, and flat polyps that spread along the bowel wall rather than standing up from it, used to be treated by removing a section of the bowel surgically. Most can now be removed at colonoscopy, by endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD).

In EMR, fluid is injected under the polyp to lift it away from the deeper layers of the bowel wall. The raised polyp is then removed with a wire snare, in one piece if it is small enough or in several pieces if it is large. The edges are treated to reduce the chance of any left behind, and clips are sometimes placed to close the area. The whole procedure is done through the colonoscope, with no cuts to the abdomen.

ESD is a different technique, in which the polyp is cut away in a single piece from the deeper layer of the bowel wall with a fine electrical knife. It takes longer than EMR and is used for selected polyps, mainly where the appearance raises concern about early cancer and removal in one piece gives the pathologist the most information.

A/Prof Kariyawasam performs EMR. He does not perform ESD. Where a polyp is better suited to ESD, he arranges referral to a colleague who performs it and stays involved in the follow-up.

Large polyps are sometimes seen at a first colonoscopy and then removed at a second, planned procedure, so that the right time, equipment and setting are available. Which method suits a particular polyp is discussed after the first colonoscopy. Where the appearance suggests cancer has grown into the deeper wall, surgery may still be the better choice, and that decision is made with a colorectal surgeon.

The training behind this work is an advanced therapeutic endoscopy fellowship, and A/Prof Kariyawasam's published research includes series on resecting large and complex lesions endoscopically.

What the evidence shows

Much of the evidence for EMR of large colonic polyps comes from Australia. In the Australian Colonic EMR study, a multicentre series of 1,000 successful resections of polyps 2 cm or larger, some polyp tissue was found at the first check colonoscopy in 16 per cent of people. It was usually tiny, and almost all of it was removed at that same check. Recurrence at the second check was 4 per cent. Where the first resection was successful and there was no deeper invasion needing surgery, 98 per cent of people were clear of polyps and had avoided surgery 16 months later.

That is why the follow-up checks matter. They are part of the treatment, not an optional extra.

What are the risks

EMR carries more risk than removing a small polyp and less than bowel surgery. The main risks are:

• Bleeding, either during the procedure, when it is usually controlled there and then, or in the days afterwards, occasionally needing a return to hospital and a further colonoscopy
• Perforation, a hole in the bowel wall, which is uncommon and is usually recognised and closed with clips during the procedure. Rarely it needs surgery
• Post-polypectomy syndrome, pain and sometimes fever from heat applied to the bowel wall, which usually settles with observation and sometimes antibiotics

The individual risk depends on the size and position of the polyp and on blood thinners and other health conditions, and is discussed before the procedure.

Afterwards

Most people go home the same day. Some, particularly after a very large resection, are kept overnight. A light diet for the rest of the day is usual. Blood thinners are restarted according to a plan made in advance.

Some bleeding in the first bowel motion is not unusual. Heavy or repeated bleeding, severe or increasing abdominal pain, fever or vomiting in the days afterwards are not normal. Contact the rooms or the hospital straight away, and if it is severe, go to an emergency department.

The follow-up checks

A check colonoscopy is usually booked for about six months after a large polyp has been removed in pieces, to look at the scar and remove anything left behind, and again about a year after that. Routine surveillance then follows the national guidelines.

Where polyp removal and EMR are performed in Sydney

A/Prof Viraj Kariyawasam is a consultant gastroenterologist and hepatologist with an advanced therapeutic endoscopy fellowship. Large or complex polyps referred for removal are assessed at consultation in Norwest, Rouse Hill, Pennant Hills and Macquarie Park.

The resection is performed during a colonoscopy at Norwest Private Hospital, Macquarie University Hospital and Pennant Hills Day Surgery. A referral from your GP is needed for a consultation.