Advanced Tissue Resection in Gastroenterology: Indications, Role, and Outcomes
Submucosal Tunneling Endoscopic Resection (STER)
STER has emerged as a well-established technique for the endoscopic resection of GI subepithelial tumors (SETs) originating from the muscularis propria layer. The standard STER procedure involves a series of steps including submucosal elevation proximal to the SET, mucosotomy, creation of a submucosal tunnel, dissection of the SET within the tunnel, enucleation from the deep muscle layer, and subsequent specimen retrieval followed by mucosal closure.
This technique is typically recommended for SETs smaller than 3.5 cm, particularly those located in the mid or distal esophagus, cardia, or along the greater curvature of the gastric body.18 However, STER may pose technical challenges for larger SETs or lesions in anatomically difficult locations, where surgical resection is recommended instead.19 Notably, recent large-scale meta-analyses have showcased the favorable complete resection and en bloc resection rates of STER in treating GI SETs.20
Endoscopic Full Thickness Resection (EFTR)
EFTR has emerged as a valuable technique in the endoscopic management of gastrointestinal lesions, particularly SETs and lesions not amenable to EMR or ESD due to fibrosis. EFTR involves the resection of all layers of the GIT from mucosa to serosa, and therefore is well-suited for SETs arising from the muscularis propria (MP).20
EFTR entails two main concepts: tissue resection and complete defect closure. Conventional EFTR consists of several steps, which include mucosal and submucosal pre-cutting, circumferential incision, and dissection through the MP or serosa. This results in a full thickness defect, for which closure of the wall defect is achieved using standard endoscopic clips or a combination of clips and endoloops or endoscopic suturing.21 For lesions less than 2 cm, EFTR can be performed in a single step using a cap-mounted full thickness resection device (FTRD). This results in deployment of over-the-scope clip over the target lesion followed by snaring the lesions above the clip.21
Location of the SET generally dictates the specific modality of ATR. For example, esophageal SETs may be more amenable to STER given that the lesion typically runs parallel with the lumen of the tubular esophagus, which allows for easier dissection without the need of full or partial retroflexion. While gastric SETs can be resected with STER, it may be challenging and more effectively addressed with EFTR, particularly when the entire lesion can be grasped into the full-thickness resection device.22 Limited data exists for duodenal EFTR, and colorectal SETs closure is particularly challenging.
Conclusion
It is key to emphasize that ATR cannot be safely established in practice without the incorporation of a multidisciplinary team (surgeons, radiologists, etc.), specialized tools, and trained personnel. This requires dedicated endoscopic rooms, careful patient selection, and a comprehensive approach to patient care before, during, and after these procedures.
Moreover, it is important to note that some patients may require post-procedure hospitalization for observation to ensure no early complications are encountered. Optimal surveillance strategies after ATR rely heavily on the potential for residual or recurrent disease, underlying pathology, and the expertise of the advanced endoscopist. As the field continues to evolve, ongoing research and technological advances of devices will further enhance the efficacy and safety of ATR in gastroenterology.
Dr. Madi (@MahMadi90) is based in the Division of Gastroenterology and Hepatology, Saint Louis University School of Medicine, Saint Louis, Missouri. Dr. Rengarajan (@ArvindRenga) and Dr. Bazarbashi (@AhmadBazarbashi) are based in the Division of Gastroenterology, Washington University in St. Louis. The authors have no conflicts of interest to disclose, and no funding was required for this project.
References
1. Copland AP, et al. AGA Clinical Practice Update on appropriate and tailored polypectomy: Expert review. Clin Gastroenterol Hepatol. 2024 Mar. doi: 10.1016/j.cgh.2023.10.012.
2. Lee SP, et al. Effect of preceding biopsy on the results of endoscopic submucosal dissection for colorectal laterally spreading tumor. Dig Dis Sci. 2019 Oct. doi: 10.1007/s10620-019-05625-3.
3. Medina-Prado L, et al. When and how to use endoscopic tattooing in the colon: An international Delphi agreement. Clin Gastroenterol Hepatol. 2021 May. doi: 10.1016/j.cgh.2021.01.024.
4. Rashid MU, et al. EMR and ESD: Indications, techniques and results. Surg Oncol. 2022 Aug. doi: 10.1016/j.suronc.2022.101742.
5. Castro R, et al. Solutions for submucosal injection: What to choose and how to do it. World J Gastroenterol. 2019 Feb. doi: 10.3748/wjg.v25.i7.777.
6. Rex DK. Best practices for resection of diminutive and small polyps in the colorectum. Gastrointest Endosc Clin N Am. 2019 Oct. doi: 10.1016/j.giec.2019.06.004.
7. Lv XH, et al. Underwater EMR for nonpedunculated colorectal lesions. Gastrointest Endosc. 2023 Apr. doi: 10.1016/j.gie.2022.10.044.
8. Fujiya M, et al. Efficacy and adverse events of EMR and endoscopic submucosal dissection for the treatment of colon neoplasms: a meta-analysis of studies comparing EMR and endoscopic submucosal dissection. Gastrointest Endosc. 2015 Mar. doi: 10.1016/j.gie.2014.07.034.
9. Kandel P, Wallace MB. Colorectal endoscopic mucosal resection (EMR). Best Pract Res Clin Gastroenterol. 2017 Aug. doi: 10.1016/j.bpg.2017.05.006.
10. Kemper G, et al; ENDOCARE Study Group. Endoscopic techniques to reduce recurrence rates after colorectal EMR: systematic review and meta-analysis. Surg Endosc. 2021 Oct. doi: 10.1007/s00464-021-08574-z.
11. Goto O, et al. Expanding indications for ESD: submucosal disease (SMT/carcinoid tumors). Gastrointest Endosc Clin N Am. 2014 Apr. doi: 10.1016/j.giec.2013.11.006.
12. Wang K, et al. Endoscopic full-thickness resection, indication, methods and perspectives. Dig Endosc. 2023 Jan. doi: 10.1111/den.14474.
13. Herreros de Tejada A. ESD training: A challenging path to excellence. World J Gastrointest Endosc. 2014 Apr 16. doi: 10.4253/wjge.v6.i4.112.
14. Chiba H, et al. Safety and efficacy of simultaneous colorectal ESD for large synchronous colorectal lesions. Endosc Int Open. 2017 Jul. doi: 10.1055/s-0043-110567.
15. Mannath J, Ragunath K. Endoscopic mucosal resection: who and how? Therap Adv Gastroenterol. 2011 Sep. doi: 10.1177/1756283X10388683.
16. Wang XY, et al. Hybrid endoscopic submucosal dissection: An alternative resection modality for large laterally spreading tumors in the cecum? BMC Gastroenterol. 2021 May. doi: 10.1186/s12876-021-01766-w.
17. McCarty TR, et al. Hybrid endoscopic submucosal dissection (ESD) compared with conventional ESD for colorectal lesions: a systematic review and meta-analysis. Endoscopy. 2021 Oct. doi: 10.1055/a-1266-1855.
18. Jain D, et al. Submucosal tunneling endoscopic resection of upper gastrointestinal tract tumors arising from muscularis propria. Ann Gastroenterol. 2017 Feb. doi: 10.20524/aog.2017.0128.
19. Lv XH, et al. Efficacy and safety of submucosal tunneling endoscopic resection for upper gastrointestinal submucosal tumors: a systematic review and meta-analysis. Surg Endosc. 2017 Jan. doi: 10.1007/s00464-016-4978-7.
20. Cao B, et al. Efficacy and safety of submucosal tunneling endoscopic resection for gastric submucosal tumors: a systematic review and meta-analysis. Rev Esp Enferm Dig. 2021 Jan. doi: 10.17235/reed.2020.6989/2020.
21. Cai M, et al. Endoscopic full-thickness resection (EFTR) for gastrointestinal subepithelial tumors. Gastrointest Endosc Clin N Am. 2016 Apr. doi: 10.1016/j.giec.2015.12.013.
22. Brigic A, et al. A systematic review regarding the feasibility and safety of endoscopic full thickness resection (EFTR) for colonic lesions. Surg Endosc. 2013 Oct. doi: 10.1007/s00464-013-2946-z.
