Third space endoscopy encompasses several endoscopic procedures that are performed in the “third space”, which is the potential space inside the wall of the GI tract. Most commonly, this means working in the submucosal layer of the organ wall. The two most common procedures performed in the third space are Per Oral Endoscopic Myotomy (POEM), and Endoscopic Submucosal Dissection (ESD). Other examples of third space endoscopy performed at Duke include Zenker’s Diverticulotomy (ZPOEM), endoscopic gastric pyloromyotomy (GPOEM), submucosal tunneling endoscopic resection (STER), and tunneling recanalization of the esophagus (POETRE).
While not performed in the third space, several other advanced luminal endoscopy procedures are performed by the third space endoscopy team here at Duke, including endoscopic mucosal resection (EMR), full thickness resection (FTRD), Endorotor resection device, transoral incisionless fundoplication (TIF), endoscopic suturing, and endoscopic stent placement.
Because all of these procedures are highly specialized and require complex medical decision making, the third space endoscopy team works closely with the Esophageal Center at Duke (ECD) and the Duke Cancer Center, as well as the thoracic, bariatric, colorectal, and general surgery services. To that end, medical decision making often occurs in collaboration with these programs through regularly scheduled multi-disciplinary conferences.
Providers: Darin Dufault, MD (Program Director), Stan Branch, MD, Joshua Spaete, MD
POEM
POEM (Per Oral Endoscopic Myotomy) is part of our third space endoscopy program. It is a minimally invasive endoscopic procedure performed for the treatment of motility disorders of the esophagus, such as achalasia, diffuse esophageal spasm, jackhammer esophagus, and esophagogastric junction outlet obstruction (EGJOO). POEM is performed in a similar fashion to standard upper endoscopy but requires specialized training and tools to perform. POEM is an alternative option to a surgical Heller’s esophageal myotomy. Importantly, some patients are not able to be treated with POEM, despite these most advanced endoscopic techniques, so we perform thorough pre-procedure evaluations to determine whether POEM is a good option for them.
G-POEM
G-POEM stands for Gastric Per Oral Endoscopic Myotomy. It is a minimally invasive endoscopic procedure performed for the treatment of conditions where permanent relaxation of the pylorus muscle is helpful to improve a person’s condition. The most common condition treated with G-POEM is gastroparesis or delayed gastric emptying. People can develop delayed gastric emptying as a result of diabetes, surgeries, and some medications, among other reasons. POEM is performed in much the same way as a standard upper endoscopy but requires specialized training and tools to perform. Importantly, some patients are not able to be treated with G-POEM despite these most advanced endoscopic techniques, so it is important for patients to meet with the performing physician to determine whether G-POEM is a good option.
ESD
ESD (Endoscopic Submucosal Dissection) is part of our third space endoscopy program. It is a minimally invasive endoscopic procedure performed to remove lesions from the GI tract, such as advanced polyps and early cancers from the esophagus, stomach, colon, and rectum. In this way, the main goal of ESD is to avoid unnecessary surgery for patients who have lesions that are able to be removed endoscopically. ESD is performed in much the same way as standard endoscopic procedures and colonoscopies but requires specialized training and tools to perform. Importantly, some lesions are not able to be removed endoscopically despite these advanced endoscopic techniques, so we perform thorough pre-procedure evaluations to determine whether ESD is a good option.
EMR
EMR (Endoscopic Mucosal Resection) is an endoscopic technique used to remove lesions from the GI tract such as polyps within the esophagus, stomach, small bowel, colon or rectum. It is very effective for removal of large polyps and lesions within the GI tract in cases where more advanced techniques such as ESD are not required or cannot be performed. Other techniques and tools can be used in conjunction with EMR to more effectively remove polyps or lesions that may not have been completely removed previously. Some of these tools include a full thickness resection device as well as a through the scope interventional resection device (these devices are described in detail separately). Some lesions cannot be removed endoscopically, so we perform thorough pre-procedure evaluations to determine whether EMR is a good option.
EndoRotor®
EndoRotor® is an interventional resection device that can be inserted through an endoscope at the time of an endoscopic procedure to allow for treatment of difficult lesions within the GI tract. It can be used in the esophagus, small bowel and colon. It allows for shaving of lesions to remove any remaining polyp tissue at the time of EMR or at sites where polyps have previously been treated and scar tissue prevents removal of the remaining lesion.
FTRD
FTRD (full thickness resection device) is a device that attaches to the distal end of an endoscope and can be used to remove lesions within the GI tract. It is used mainly in the colon but can be used in other locations in the GI tract. It can allow for complete removal of polyps or deeper lesions within the wall of the as well as obtaining very deep biopsies from the wall of the GI tract. It may also be used at the time of colonoscopy or at sites where polyps have previously been treated and scar tissue prevents removal of the remaining tissue.
TIF
TIF (Transoral Incisionless Fundoplication) is a minimally invasive endoscopic procedure performed to treat esophageal reflux that is unable to be adequately controlled with acid reducing medications. Some reasons esophageal reflux may not be able to be controlled with medications alone include failure of the anti-reflux barrier in the body, non-responsiveness to acid reducing medications, or inability to tolerate side effects related to the medications. TIF is performed in much the same way as a standard upper endoscopy, but requires specialized training and tools to perform. TIF is an alternative option to Nissen, Dor, and Toupet fundoplications, which are the surgical equivalent of TIF. Importantly, some reflux is not able to be treated with TIF despite these most advanced endoscopic techniques, so we perform thorough pre-procedure evaluations to determine whether TIF is a good option.
Endoscopic Suturing
Endoscopic suturing is performed using a specialized suturing device placed on a standard endoscope. It is most often used to close large defects left behind when large lesions are removed endoscopically from the GI tract. It is also used to close perforations, hold endoscopically placed stents in place, and to perform endoscopic bariatric procedures, described elsewhere.
Z-POEM
Z-POEM stands for Per Oral Endoscopic Myotomy for symptomatic Zenker’s diverticulum. It is a minimally invasive endoscopic procedure performed for the treatment of a pouch that forms in the pharynx just above the entry to the esophagus. POEM is performed in much the same way as a standard upper endoscopy but requires specialized training and tools to perform. Z-POEM is an alternative option to a surgical myotomy. Importantly, some patients are not able to be treated with Z-POEM, despite these most advanced endoscopic techniques, so it is important for patients to meet with the performing physician to determine whether Z-POEM is a good option.