Update on advanced therapeutic endoscopy: Going into third space
Dr. LAM Chin Tou Dennis
Consultant in General Surgery
GI endoscopy evolved as diagnostic endoscopy to advanced therapeutic endoscopy which allows endoscopists to perform a wide variety of procedures potentially replacing traditional open or laparoscopic surgery. Initially luminal endoscopy is considered as first space, procedure of endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) are evolved to treat early GI neoplasm.
Third space endoscopy refers to a type of therapeutic procedure that allows access to the space between the submucosal and muscular layers of the gastrointestinal tract. This space, known as the third space, cannot be accessed using conventional endoscopy techniques. Third space endoscopy, or submucosal endoscopy, involves creating a small opening in the submucosal layer to access the space between the submucosal and muscular layers. This is typically done using specialized endoscopic devices and techniques. It allows visualization and biopsy of lesions or abnormalities in the third space, such as submucosal tumors. In therapeutic manner, it can be used to treat conditions like esophageal achalasia, and submucosal tumors by performing submucosal tunnel endoscopic resection. Techniques in third space endoscopy allow access to anatomical locations that are difficult to reach with conventional endoscopy. Treatment of such, will allow faster recovery and reduced complications compared to conventional surgical procedures. However, it requires specialized training and expertise for the endoscopist. The potential risks include bleeding, infection, and perforation of the gastrointestinal tract.
Moreover, not all third space lesions or conditions are amenable to this approach. Overall, third space endoscopy represents an innovative and evolving field in gastrointestinal endoscopy, providing new diagnostic and therapeutic options for patients with certain conditions affecting the deeper layers of the gastrointestinal tract.
Per oral endoscopic myotomy
Per-oral endoscopic myotomy (POEM) is a minimally invasive endoscopic procedure used to treat esophageal motility disorders, particularly achalasia. POEM is performed by creating a submucosal tunnel endoscopically, starting from the esophagus and extending into the cardia of the stomach. The inner circular muscle fibers are then selectively divided to relax the lower esophageal sphincter and restore normal esophageal function. The submucosal tunnel is then closed with clips.
Esophageal achalasia is a condition characterized by the inability of the lower esophageal sphincter to relax properly, causing swallowing difficulties. Compared to surgical Heller myotomy, POEM can avoid the need for large incisions or external abdominal access and allows faster recovery. POEM has been shown to have high success rates, with symptom improvement and objective measures of esophageal function in the majority of patients. Long-term studies have demonstrated the durability of the procedure, with sustained improvements in dysphagia in the long run. The potential complications include bleeding, infection, and acid reflux. Careful patient selection and operator experience are crucial to minimize the risk of complications. POEM has emerged as a safe and effective alternative to traditional surgical myotomy for the treatment of esophageal motility disorders, particularly achalasia, and has become an established procedure in the field of advanced gastrointestinal endoscopy.
Submucosal tunnel endoscopic resection
Injection of solution to create submucosal cushion
Mucosal incision
Submucosal tunnel creation
Dissection of the submucosal tumor
Dissection of tumor from MP layer
Removal of tumor from the tunnel
Defect of MP layer after resection after hemostasis done
Closure of mucosal incision with clips
Submucosal Tunnel Endoscopic Resection (STER) is an advanced endoscopic technique used for the removal of submucosal tumors in the gastrointestinal tract. STER is typically performed using a flexible endoscope and specialized instruments to make a mucosal incision and create a submucosal tunnel to reach the target lesion. The tumor is then dissected and completely removed through the submucosal tunnel. The mucosal defect is then closed using endoscopic clips. STER is primarily used for the removal of submucosal tumors, such as gastrointestinal stromal tumors (GISTs), leiomyomas, and lipomas. It is particularly useful for lesions located in the esophagus, stomach, or upper gastrointestinal tract. It allows for complete resection of the tumor while preserving the overlying mucosa.
Patients can have shorter hospital stays and faster recovery time compared to traditional surgical approaches. Careful patient selection is crucial, as factors like tumor size, location, and accessibility can impact the feasibility and safety of the procedure. STER has been shown to be a safe and effective technique for the removal of small to medium-sized submucosal tumors, with high rates of complete resection and low rates of recurrence. Larger or more complex lesions may require a multimodality approach, combining STER with other endoscopic or surgical techniques. STER requires specialized training and expertise, as it is a technically challenging procedure. Potential complications include bleeding, perforation, infection, and recurrence of the tumor. – Long-term outcomes and the durability of STER are still being evaluated, as it is a relatively newer technique compared to other endoscopic resection methods. STER has emerged as an important minimally invasive alternative to traditional surgical approaches for the management of submucosal tumors in the gastrointestinal tract, offering potential benefits in terms of reduced invasiveness and
faster recovery.
Endoscopic full thickness resection
Submucosal lesion at high lesser curve
Circumferential marking with dual knife
Submucosal injection of lifting solution as a submucosal cushion
Mucosal incision around the lesion
Dissection of tumor away from MP layer
Further dissection of tumor from serosa of stomach
Serosa exposed and full thickness perforation made
Defect after excision with peritoneal fat seen
Water tight closure of defect with hemo-clip
Endoscopic Full-Thickness Resection (EFTR) is a specialized endoscopic technique used to remove lesions or tumors that extend through the full thickness of the gastrointestinal (GI) wall. EFTR involves the complete resection of a targeted lesion, including the full-thickness of the GI wall, using endoscopic techniques. The procedure typically starts with the creation of a mucosal incision around the lesion as if endoscopic submucosal dissection (ESD). The lesion is then resected using specialized endoscopic devices or knives. The resulting defect in the GI wall is then closed using endoscopic suturing or over-the-scope clips. EFTR is primarily used for the removal of lesions or tumors that are not amenable to conventional endoscopic resection techniques, such as endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD). It is typically used for the management of submucosal tumors, gastrointestinal stromal tumors (GISTs), and other lesions that involve the full-thickness of the GI wall. EFTR allows for the complete removal of lesions that cannot be adequately addressed with standard endoscopic techniques. EFTR has been shown to be a safe and effective technique for the removal of select GI lesions, with high rates of complete resection and low rates of complications.
However, EFTR is a technically challenging procedure, and careful patient selection and the expertise of the endoscopist are crucial to ensure the success and safety of the procedure. Potential complications of EFTR include bleeding, perforation, infection, and inadvertent injury to adjacent organs or structures. The risk of complications may be higher compared to other endoscopic resection techniques, due to the full-thickness nature of the procedure. EFTR represents an important advancement in the field of advanced endoscopic techniques, providing a minimally invasive option for the management of select GI lesions that are not amenable to standard endoscopic resection methods.
Conclusion
In conclusion, advanced therapeutic endoscopy matured as a potential source of replacement of traditional open or even minimal invasive surgery, particular in upper GI disease. With careful case selection and availability of expertise, a wide variety of pathology can be dealt with by purely endoscopic means, without a need for surgical scars, in a totally minimal invasive manner.
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