Endoscopic GI Procedures: An Overview

Endoscopic gastrointestinal (GI) procedures refer to operations in the GI tract that work through small, flexible tubes and are less invasive than open surgery. Endoscopic GI procedures often aim to remove bodies such as tumors and lesions from the GI tract. Two common types are endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD).  

Before exploring EMR and ESD in detail, it is important to note that both are forms of endoscopic resection (ER), meaning that they are each endoscopic procedures that can treat neoplastic lesions and, in some cases, cancers in the GI tract [1]. ER is most effective at treating lesions on the mucosa and shallow levels of the submucosa, hence the prevalence of EMR and ESD procedures [1]. ER is often used to treat early colon, gastric, and esophageal cancers; remove large colon polyps; and address dysplasia in Barnett’s esophagus [1]. 

EMR treats abnormal tissues found on the lining of the GI tract [2]. It involves passing an endoscope down the patient’s throat or through the anus to access an abnormality in the GI tract [2]. The injection of EMR solution elevates the lesion so that it can be removed by a polypectomy snare [3]. The procedure is highly effective and safe [4]. 

Regardless, as with any treatment, EMR has its disadvantages. Risks of the procedure include narrowing of the esophagus due to scarring, puncture of the digestive tract, or bleeding [2]. Moreover, patients may experience side effects such as gas, cramps, or sore throat following the procedure; fortunately, these occurrences tend to be mild and limited to the first 24 hours after the procedure [2]. One last consideration is EMR’s inability to treat larger, deeper tumors in one go and medical professionals’ subsequent difficulty confirming that all traces of the tumors have been removed [5]. Consequently, alternative procedures may be more appropriate in certain cases [5]. 

ESD differs from EMR in that it targets bodies in the submucosa, the outer layer of the mucosa [6]. Prominent medical societies recommend ESD for the treatment of “LST-non granular (NG), Kudo-VI type, large depressed and protruded colonic lesions with shallow submucosal invasion” [7]. Compared to EMR, endoscopic submucosal dissection has a higher curative resection rate and lower recurrence rate, making it more appropriate for larger colonic lesions [7].  

With respect to the disadvantages of this procedure, it can be difficult to treat lesions with severe fibrosis —such as local recurrent or residual lesions, and lesions associated with a non-negligible risk of lymph node metastasis— with ESD [3, 8]. Moreover, as is the case generally with endoscopic resection, this procedure is not optimal for removing colorectal tumors due to the risk of perforation, failure, and technical difficulties [8]. Lastly, ESD has a higher complication rate than EMR: Bleeding occurs in 11% of cases and perforation occurs in 16% [3, 7]. Nevertheless, complete recovery is the norm [3]. 

Although EMR and ESD are just two types of endoscopic GI procedures, they demonstrate the versatility and efficacy of these treatments in particular contexts. By providing an alternative to open surgery, they promote faster recovery and lower medical costs. As a result, gastroenterologists should consider employing endoscopic GI techniques to avoid unnecessarily intensive procedures where appropriate. 

References 

1. N. T. Gunaratnam and E. Zolotarevsky, “Overview of endoscopic resection of gastrointestinal tumors,” UpToDate, Updated Nov. 8, 2021. [Online]. Available: https://www.uptodate.com/contents/overview-of-endoscopic-resection-of-gastrointestinal-tumors. 
2. Mayo Clinic, “Endoscopic mucosal resection,” Updated June 11, 2022. [Online]. Available: https://www.mayoclinic.org/tests-procedures/endoscopic-mucosal-resection/about/pac-20385213. 
3. F. Purchiaroni, G. Costamagna, and C. Hassan, “Quality in upper gastrointestinal endoscopic submucosal dissection,” Annals of Translational Medicine, vol. 6, no. 13, July 2018. [Online]. Available: https://doi.org/10.21037%2Fatm.2018.02.27. 
4. J. Y. Choi et al., “Safety and effectiveness of endoscopic mucosal resection or endoscopic submucosal dissection for gastric neoplasia within 2 days’ hospital stay,” Medicine, vol. 98, no. 32, August 2019. [Online]. Available: https://doi.org/10.1097%2FMD.0000000000016578. 
5. Johns Hopkins Medicine, “Endoscopic Mucosal Resection.”  [Online]. Available: https://www.hopkinsmedicine.org/health/treatment-tests-and-therapies/endoscopic-mucosal-resection. 
6. National Cancer Institute, “General Structure of the Digestive System,” National Institute of Health.  [Online]. Available: https://training.seer.cancer.gov/anatomy/digestive/structure.html. 
7. T. Keihanian and M. O. Othman, “Colorectal Endoscopic Submucosal Dissection: An Update on Best Practice,” Clinical and Experimental Gastroenterology, vol. 14, pp. 317-330, August 2021. [Online]. Available: https://doi.org/10.2147%2FCEG.S249869.  
8. K. Suzuki, S. Saito, and Y. Fukunaga, “Current Status and Prospects of Endoscopic Resection Technique for Colorectal Tumors,” Journal of the Anus, Rectum and Colon, vol. 5, no. 2, pp. 121-128, April 2021. [Online]. Available: https://doi.org/10.23922%2Fjarc.2020-085.