Endoscopic mucosal resection (EMR) is a technique to remove irregular tissue from the digestive tract. EMR can remove early-stage cancer, tissue that may become cancer or other tissues that aren't typical, called lesions.

Healthcare professionals do endoscopic mucosal resection using a long, narrow tube called an endoscope. The endoscope is equipped with a light, video camera and other tools. During EMR of the upper digestive tract, healthcare professionals pass the endoscope down the throat. They guide it to lesions in the esophagus, stomach or upper part of the small intestine, called the duodenum.

To remove lesions from the colon, healthcare professionals guide a similar tube called a colonoscope through the anus.

EMR mainly is used as a treatment. It's also used to collect tissue for lab testing. If the lab finds cancer, additional imaging tests can help find out if the cancer has spread to tissues beneath the digestive tract lining.

Endoscopic mucosal resection can remove irregular tissues from the lining of the digestive tract without making cuts through the skin or removing a part of the gut. This makes EMR a less invasive treatment choice than surgery. Compared with surgery, EMR is linked with fewer health risks and lower costs. Tissues removed with EMR may be:

• Early-stage cancer.
• Lesions that may become cancer, also called precancerous lesions or dysplasias.

Most often, a doctor called a gastroenterologist does endoscopic mucosal resections. This type of doctor finds and treats conditions of the digestive system. If you need to have EMR, try to choose a gastroenterologist who has lots of experience doing the procedure.

Risks of endoscopic mucosal resection include:

• Bleeding. This is the most common concern. Healthcare professionals can find and fix bleeding during or after EMR.
• Narrowing of the esophagus. The esophagus is the long, narrow tube that runs from the throat to the stomach. Removing a lesion that encircles the esophagus carries a risk of scarring that narrows the esophagus. This narrowing may lead to trouble swallowing, and more treatment may be needed as a result.
• Puncture, also called perforation. There's a small chance that endoscopy tools could puncture the wall of the digestive tract. The risk depends on the size and location of the lesion that's removed.

Call your healthcare professional or get emergency care if you notice any of the following symptoms after EMR:

• Fever.
• Chills.
• Vomiting, especially if the vomit looks like coffee grounds or has bright red blood in it.
• Black stool.
• Bright red blood in the stool.
• Pain in the chest or stomach area.
• Shortness of breath.
• Fainting.
• Trouble swallowing or throat pain that becomes worse.

Before you have endoscopic mucosal resection, your healthcare team asks you for the following information:

• All medicines and dietary supplements you take and their doses. For instance, it's important to list any blood-thinning medicines, aspirin, ibuprofen (Advil, Motrin IB, others), naproxen sodium (Aleve), iron supplements, and medicines for diabetes, blood pressure or arthritis.
• Any medicine allergies.
• All health conditions you have, including heart disease, lung disease, diabetes and blood-clotting disorders.

Your healthcare professional may ask you to stop taking some medicines for a short time before EMR. This includes medicines that affect blood clotting or those that interfere with medicines called sedatives that help you relax before EMR.

You receive written instructions about what to do the day before your EMR. These instructions may vary depending on the location of the lesion or lesions being removed. In general, the instructions likely will include:

• Fasting. You're told how soon to stop eating and drinking, also called fasting, before the EMR. You may not be able to eat, drink, chew gum or smoke after midnight before the EMR. You may be asked to follow a clear liquid diet the day before your procedure.
• Cleaning the colon. If the EMR involves the colon, you'll take some steps to empty your bowels and clean your colon beforehand. To do this, you may be told to use medicine called a liquid laxative. Or you might use a device called an enema kit that sends water into the rectum.

You'll also sign an informed consent form. This gives your healthcare professional permission to do the EMR after the risks and benefits have been explained to you. Before you sign the form, ask your healthcare professional about anything you don't understand about the procedure.

Travel arrangements

You'll likely go home the day of your EMR, but you'll need to have someone take you home. The effects of medicines used to help you relax take time to wear off. So it's too risky to drive yourself home. Depending on the situation, some people need to be observed in the hospital after EMR.

There are a few versions of endoscopic mucosal resection. Ask your gastroenterologist about how your EMR will be done. A common approach includes these steps:

• Inserting the endoscope and guiding the tip to the area of concern.
• Injecting a fluid under a lesion to create a cushion between the lesion and healthy tissue underneath it.
• Lifting the lesion, possibly using gentle suction.
• Cutting the lesion to separate it from surrounding healthy tissue.
• Removing tissue that isn't typical from within the body.
• Marking the treated area with ink so that it can be found again with future endoscopic exams.

During the procedure

During an endoscopic mucosal resection, you can expect the following:

• Your role. You'll be asked to change into a gown before the EMR. During the EMR, you'll lie on your side on a cushioned table.
• Medicine to numb the throat. If the endoscope is placed down your throat, your healthcare professional may spray your throat with numbing medicine. Or you may be asked to gargle a solution to numb your throat. Either method makes you more comfortable once your healthcare professional inserts the endoscope. These numbing medicines that help prevent pain in a certain body part are known as local anesthetics.
• Anesthetic or sedative medicine. Before EMR, some people receive medicine that puts them in a sleep-like state and prevents pain. This is called an anesthetic. Other people are given medicine called sedatives. Moderate sedation causes you to be relaxed and drowsy. You may feel slight movement or pressure during the EMR, but you shouldn't feel pain. Or you may be heavily sedated. Ask your gastroenterologist what option is right for you.
• Monitoring. Nurses or other health professionals watch your heart rate, blood pressure, blood oxygen level and comfort while the doctor does the EMR.

After the procedure

You'll rest in a recovery room until most of the sedative's effects have worn off. You receive written instructions about when you can start eating, drinking and getting back to your usual activities.

Somewhat mild side effects may happen within 24 hours after the EMR, including:

• Reactions to the sedative. You may keep feeling drowsy. You also may have an upset stomach and vomiting.
• Sore throat. If the endoscope was guided down your esophagus, your throat may be sore.
• Gas or cramps. During some EMRs, air is pumped into the digestive system. This makes it easier for the healthcare professional to see your organs with the endoscope. If air is pumped into your digestive system, you may have gas, bloating or cramps after your EMR.

You'll also receive written instructions about when to call your healthcare professional or get emergency care after the EMR. The following symptoms may be clues of a serious complication from endoscopic mucosal resection:

• Fever.
• Chills.
• Vomiting, especially if the vomit looks like coffee grounds or has bright red blood in it.
• Black stool.
• Bright red blood in the stool.
• Pain in the chest or stomach area.
• Shortness of breath.
• Fainting.
• Trouble swallowing or throat pain that becomes worse.

You'll likely have a follow-up appointment with a gastroenterologist. The doctor talks with you about the outcome of your endoscopic mucosal resection and lab tests done on lesion samples. Questions to ask your healthcare professional include:

• Were you able to remove all tissues that didn't look typical?
• What were the results of the lab tests? Were any of the tissues cancerous?
• Do I need to see a cancer specialist called an oncologist?
• If the tissues are cancerous, will I need more treatments?
• How will you monitor my condition?

Follow-up exams

Usually, you get a follow-up exam 3 to 12 months after your endoscopic mucosal resection. That way, your healthcare team can make sure the entire lesion was removed. Depending on the findings, your healthcare professional advises you about further exams.

A follow-up exam likely will include a visual check of the treated area using an endoscope.