Endoscopic submucosal dissection (ESD) is a minimally invasive procedure that removes abnormal tissue from the lining of the digestive tract without traditional surgery. A specialist passes a thin, flexible scope through your mouth or rectum, then uses a small electrical knife to carefully peel away a lesion, such as an early-stage cancer or a large precancerous growth, in one complete piece. It’s most commonly performed in the stomach, esophagus, and colon.
The key advantage of ESD is that it removes the entire lesion intact, which gives pathologists a complete specimen to examine under a microscope. This confirms whether the growth was fully removed with clear margins, a critical factor in determining whether further treatment is needed.
How ESD Works Step by Step
The procedure follows a sequence of four intertwined phases: injection, incision, access, and dissection. First, the doctor injects a special fluid underneath the abnormal tissue. This lifts the lesion away from the deeper muscle wall, creating a cushion of space to work in safely. The injection contains ions that conduct electrical current, and when placed correctly, it forms a visible bluish bubble beneath the surface tissue.
Once the tissue is lifted, the doctor makes a small incision around the edges of the lesion, staying far enough from the abnormal area to preserve a healthy margin. This incision is made with a specialized endoscopic knife, of which there are many designs. Some look like tiny needles, others like miniature scissors or hooks. Each is designed to cut precisely while minimizing damage to surrounding tissue.
After the initial cut, the doctor works into the layer just beneath the surface (the submucosa) and gradually peels the lesion free. This is the most technically demanding phase. The doctor must repeatedly reinject fluid to keep the tissue lifted, alternate between cutting and coagulating to control bleeding, and maintain clear visibility throughout. Staying deep in the submucosal layer is important both for cancer safety margins and for avoiding blood vessels that branch closer to the surface. The entire process can take anywhere from 30 minutes to several hours depending on the size and location of the lesion.
Why ESD Instead of Standard Endoscopic Removal
The older and more common alternative is endoscopic mucosal resection (EMR), which uses a wire snare to lasso and cut away tissue. EMR works well for smaller growths, but for anything larger than about 2 centimeters, the snare often can’t capture the entire lesion in one pass. The doctor ends up removing it in multiple fragments, which makes it harder to confirm that every bit of abnormal tissue was taken out.
ESD was developed specifically to solve this problem. In a meta-analysis comparing the two techniques for colorectal tumors, ESD achieved a complete single-piece removal rate of about 88% (604 out of 687 cases) compared to roughly 44% for EMR (306 out of 688 cases). More importantly, the local recurrence rate was dramatically lower with ESD: about 1% versus nearly 13% with EMR. This difference matters because recurrence can mean repeat procedures or, in some cases, progression to a more advanced cancer.
Despite these advantages, ESD isn’t always the right choice. It takes longer, requires more specialized training, and is best suited for lesions that are confined to the surface layers of the digestive tract. Growths that have already invaded deeply into the wall aren’t good candidates for any endoscopic removal and typically require surgery.
Who Is a Candidate for ESD
ESD is primarily used for early-stage cancers and large precancerous lesions in the esophagus, stomach, and colon. The ideal candidate has a growth that appears confined to the mucosal or superficial submucosal layer, with no signs of deep invasion. Doctors use detailed endoscopic imaging and sometimes ultrasound to assess depth before recommending the procedure.
Several factors can make ESD difficult or inappropriate. Lesions with heavy scarring from previous removal attempts are harder to dissect safely. Extremely large growths may extend the procedure time to a point where the risks outweigh the benefits. Patients who are elderly or frail may not tolerate a long procedure under sedation well. And if imaging suggests the cancer has already spread into deeper tissue layers, endoscopic removal won’t be sufficient.
Risks and Complications
ESD is considered safe, but it does carry more technical risk than standard endoscopic removal. The two main complications are perforation (accidentally cutting through the full wall of the organ) and bleeding after the procedure.
Perforation during gastric ESD occurs in roughly 1% to 8% of cases, depending on the center’s experience level. High-volume centers report rates closer to 0.5%. Most perforations are small and can be closed immediately with endoscopic clips during the same procedure, avoiding the need for emergency surgery.
Post-procedure bleeding is more common, reported in about 5% to 16% of gastric ESD cases. This bleeding typically occurs within the first couple of days and is usually manageable with a follow-up endoscopy to cauterize or clip the bleeding site. Stricture, or narrowing of the organ where the tissue was removed, is less common, occurring in about 1% to 2% of cases. It’s most likely when a large area of the esophagus or stomach is resected.
Recovery and Follow-Up
Hospital stays after ESD are typically short. Many centers discharge patients within one to three days depending on the size of the resection and whether any complications arise. You’ll start with clear liquids on the day of the procedure and progress to soft foods, then a normal diet over the following day or two. Research comparing early feeding to prolonged fasting after gastric ESD found no difference in complication rates, but patients who ate sooner reported higher satisfaction and shorter hospital stays.
A follow-up endoscopy is generally performed within two days to check the resection site for bleeding, and another is scheduled around two months later to confirm healing. After that, surveillance endoscopies continue at regular intervals, often annually, to monitor for any recurrence at the site or new lesions elsewhere.
How Successful Is ESD
Success in ESD is measured by whether the lesion was removed in one piece (en bloc resection) and whether the margins were completely clear of abnormal cells (R0 resection). In experienced Eastern centers, where ESD originated and has been practiced the longest, en bloc rates for gastric ESD reach 97% to 100%, with R0 rates of 91% to 96%. Western centers, where the technique is newer, report slightly lower but still strong results: 91% to 96% en bloc and 75% to 94% R0.
Age alone doesn’t appear to significantly affect outcomes. Studies of patients in their 70s, 80s, and beyond show R0 rates comparable to younger patients, around 76% to 79% in Western series. This supports ESD as a viable option for older adults who want to avoid major surgery, provided they can tolerate the procedure itself.
When pathology confirms a complete R0 resection with favorable features (no deep invasion, no involvement of blood or lymph vessels), the procedure is often curative on its own, with no need for additional surgery or treatment. When margins are unclear or the pathology reveals deeper invasion than expected, surgery may still be recommended as a follow-up step.