Injectable polymeric hydrogels delivered via endoscopic catheter have emerged as promising submucosal agents, offering durable, long-lasting cushions to enhance the efficacy of endoscopic submucosal dissection (ESD) for the removal of small, flat polyps from the gastrointestinal tract (GIT). However, polymer-based injections do not meet the easy-injectability criteria via catheter because their high viscosity tends to clog the catheter needle. To the best of knowledge, for the first time, report the fabrication of an amphiphile-based small molecule hydrogel of diglycerol monostearate (DGMS) that self-assembles to form hydrogel (DGMSH) for delivery via an endoscopic catheter. Physicochemical characterization of the hydrogel reveals its fibrous morphology, shear-thinning behaviour, and easy injectability, along with its scalability and long shelf-life (6 months). Ex vivo studies on the goat's stomach and intestine demonstrate the ease of injectability through the catheters and the development of visible submucosal cushion depots with the desired height. Moreover, the hydrogel can encapsulate both hydrophobic and hydrophilic drugs/dyes. In vivo studies in small animals have found that the hydrogel depot is durable, biocompatible, non-immunogenic, and has a hemostatic effect. Endoscopic studies in the porcine model demonstrate a safe injection and endoscopic excision of GI polyps acting as a suitable agent for ESD.

Studies evaluating endoscopic full-thickness resection (EFTR) and endoscopic submucosal dissection (ESD) for complex colorectal lesions have shown variable results. We conducted a meta-analysis of the available data.

Online databases were searched for studies comparing EFTR versus ESD for complex colorectal lesions. The outcomes of interest were resection rates, procedure time (min), and complications. Pooled odds ratios (OR) and standardized mean difference (SMD) along with 95% CI were calculated.

A total of 4 studies with 530 patients (n=215 EFTR, n=315 ESD) were included. The mean follow-up duration was 5 months. The mean age of the patients was 68 years and 64% were men. The EFTR and ESD groups had similar rates of en bloc resection (OR: 1.73, 95% CI: 0.60-4.97, P =0.31) and R0 resection (OR: 1.52, 95% CI: 0.55-4.14, P =0.42). The EFTR group had significantly reduced procedure time (SMD -1.87, 95% CI: -3.13 to -0.61, P =0.004), total complications (OR: 0.24, 95% CI: 0.13-0.44, P <0.00001), perforation (OR: 0.12, 95% CI: 0.03-0.39, P =0.0005) and postresection electrocoagulation syndrome (OR: 0.06, 95% CI: 0.01-0.48, P =0.008). Delayed bleeding was similar in the 2 groups (OR: 0.80, 95% CI: 0.30-2.12, P =0.66). Residual/recurrent lesions were significantly higher in the EFTR group (OR: 4.67, 95% CI: 1.39-15.66, P =0.01).

This meta-analysis of small studies with high heterogeneity showed that EFTR and ESD have comparable resection rates for complex colorectal lesions. EFTR is faster and has fewer complications, but it increases residual or recurrent lesions.

This article provides an overview of recent advances in endoscopic resection techniques. It includes the brief overview of endoscopic submucosal dissection, regional differences in ESD indications, innovation of ESD techniques, and expansion to full-thickness resection. The article covers cold snare polypectomy for small polyps with tips, underwater endoscopic mucosal resection (U-EMR) for sessile lesions with tips and expanding role of U-EMR, and the key assistive techniques for ESD that have improved the safety and efficacy. Furthermore, it discusses the emerging field of endoscopic full-thickness resection including device-assisted and freehand exposure techniques.

 Endoscopic full-thickness resection (EFTR) is an effective and safe technique for nonlifting colorectal lesions. Technical issues or failures with the full-thickness resection device (FTRD) system are reported, but there are no detailed data. The aim of our study was to quantify and classify FTRD technical failures.

 We performed a retrospective study involving 17 Italian centers with experience in advanced resection techniques and the required devices. Each center shared and classified all prospectively collected consecutive failures during colorectal EFTR using the FTRD from 2018 to 2022. The primary outcome was the technical failure rate and their classification; secondary outcomes included subsequent management, clinical success, and complications.

 Included lesions were mainly recurrent (52 %), with a mean (SD) dimension of 18.4 (7.5) mm. Among 750 EFTRs, failures occurred in 77 patients (35 women; mean [SD] age 69.4 [8.9] years). A classification was proposed: type I, snare noncutting (53 %); type II, clip misdeployment (31 %); and type III, cap misplacement (16 %). Among endoscopic treatments completed, rescue endoscopic mucosal resection was performed in 57 patients (74 %), allowing en bloc and R0 resection in 71 % and 64 %, respectively. The overall adverse event rate was 27.3 %. Pooled estimates for the rates of failure, complications, and rescue endoscopic therapy were similar for low and high volume centers (P = 0.08, P = 0.70, and P = 0.71, respectively).

 Colorectal EFTR with the FTRD is a challenging technique with a non-negligible rate of technical failure and complications. Experience in rescue resection techniques and multidisciplinary management are mandatory in this setting.