Complex Polyps

Most polyps found during a colonoscopy can be removed safely and effectively during the procedure. In some cases, however, a colonoscopy can reveal that there are polyps too large to safely remove. These are complex polyps, which make up about 10-15% of all polyps, and usually require additional procedures to remove. If the polyp is found to be cancerous, then the patient is often referred to a surgeon. If the polyp is benign, with no signs of cancer present, then the patient may choose non-surgical removal of the polyp instead of surgery.

Treatment of complex polyps requires the expertise of a highly skilled physician. Our board-certified gastroenterologists in the Complex Polypectomy Program at the University of Michigan are specially trained in the removal of complex polyps and perform a large volume of these procedures annually for patients from all over the region.

What is a Complex Polyp?

In general, a rectal or colon polyp is considered complex (also known as “defiant”) if it meets any of the following criteria:

  • Size greater than 2 centimeters
  • Located in a difficult area or is too flat (sessile) to be removed during a standard colonoscopy
  • When the doctor performing your colonoscopy does not feel they can safely remove the polyp(s) and decide to refer you to a specialist

Non-Surgical Treatment Options

Patients with non-cancerous complex polyps may be referred for surgery to remove the polyps, however this can be more risky and invasive. In most cases, complex polyps can be removed through non-surgical endoscopic procedures that are less invasive and less expensive. These outpatient procedures allow patients to return home the same day.

There are currently two types of endoscopic removal options for complex polyps available at the University of Michigan:

Endoscopic Mucosal Resection (EMR)

The majority of complex polyps can be removed by endoscopic mucosal resection (EMR). For the patient, this procedure requires the same preparation as a colonoscopy but it can be a longer appointment. During the procedure, fluid is injected under the polyp to lift it away from the deeper colon wall after which it is dissected off. The fluid creates a cushion between the polyp and those deeper layers of colon tissue. 

Endoscopic Submucosal Dissection (ESD)

Endoscopic Submucosal Dissection (ESD) is a technique used to remove complex polyps that invade deeper into the lining of the colon. This procedure is similar in concept to EMR and can be performed on an outpatient basis.

Patients return for a follow-up colonoscopy within a couple of months of the endoscopic procedure to confirm that the polyp was completely removed, and then usually return for another colonoscopy a few years later if everything looks well.

Make an Appointment

To schedule an appointment to discuss treatment options for complex polyps with providers in the Complex Polypectomy Program, call us at 888-229-7408.