Esophageal diverticulum exposed during endoscopic submucosal dissection of superficial cancer

Outcomes of endoscopic submucosal dissection for esophageal cancer with segmental absence of intestinal musculature

BACKGROUND AND AIMS

Perforation during esophageal endoscopic submucosal dissection (ESD) typically results from electrical damage. However, there are cases in which perforation occurs because of segmental absence of intestinal musculature (SAIM) without iatrogenic muscular injury. We investigated the occurrence rate and clinical course of SAIM during esophageal ESD.

METHODS

We conducted a retrospective review of esophageal ESDs performed between 2013 and 2019 at 10 centers in Japan.

RESULTS

Five of 1708 (0.29%) patients received ESD for esophageal cancer and had SAIM. The median muscular defect size was 20 mm. All lesions were resected without discontinuation. After resection, 3 patients were closed with Endoloop. Four patients had mediastinal emphysema. All patients were managed conservatively.

CONCLUSIONS

SAIM is a very rare condition that is usually only diagnosed during ESD. Physicians performing esophageal ESD should be aware of SAIM. When SAIM is detected, the ESD technique should be modified to prevent full-thickness perforation.

Successful treatment of an esophageal perforation that occurred during endoscopic submucosal dissection for esophageal cancer using polyglycolic acid sheets and fibrin glue

A 74-year-old female, who was diagnosed with superficial esophageal cancer, underwent endoscopic submucosal dissection (ESD) at another hospital, but a perforation occurred during the procedure. The perforation was closed with endoscopic clips, and the ESD was halted. The patient was referred to our hospital, and ESD was retried. There was severe fibrosis around the lesion, and injections into the submucosal layer were difficult. In addition, it was not possible to identify the submucosal layer, and making an oral-side incision caused a large perforation along the incision line. As continuing the submucosal dissection with an endoknife was considered difficult, the lesion was finally resected with hybrid ESD using a snare. The perforation was closed using polyglycolic acid (PGA) sheets and fibrin glue. Endoscopy performed 6 days later showed that the defect had been closed, and no contrast leakage was detected. Follow-up endoscopy conducted 3 months after the ESD showed ulcer healing at the dissection site and scar formation, but no residual tumor or esophageal stricture was noted. Our experience suggests that the use of PGA sheets with fibrin glue is a feasible, safe, and effective way of treating large esophageal perforations during ESD.

New devices and techniques for endoscopic closure of gastrointestinal perforations

Gastrointestinal perforations, which need to be managed quickly, are associated with high morbidity and mortality. Treatments used to close these perforations range from surgery to endoscopic therapy. Nowadays, with the development of new devices and techniques, endoscopic therapy is becoming more popular. However, there are different indications and clinical efficacies between different methods, because of the diverse properties of endoscopic devices and techniques. Successful management also depends on other factors, such as the precise location of the perforation, its size and the length of time between the occurrence and diagnosis. In this study, we performed a comprehensive review of various devices and introduced the different techniques that are considered effective to treat gastrointestinal perforations. In addition, we focused on the different methods used to achieve successful closure, based on the literature and our clinical experiences.

Characterization of Three-Dimensional Retinal Tissue Derived from Human Embryonic Stem Cells in Adherent Monolayer Cultures

Stem cell-based therapy of retinal degenerative conditions is a promising modality to treat blindness, but requires new strategies to improve the number of functionally integrating cells. Grafting semidifferentiated retinal tissue rather than progenitors allows preservation of tissue structure and connectivity in retinal grafts, mandatory for vision restoration. Using human embryonic stem cells (hESCs), we derived retinal tissue growing in adherent conditions consisting of conjoined neural retina and retinal pigment epithelial (RPE) cells and evaluated cell fate determination and maturation in this tissue. We found that deriving such tissue in adherent conditions robustly induces all eye field genes (RX, PAX6, LHX2, SIX3, SIX6) and produces four layers of pure populations of retinal cells: RPE (expressing NHERF1, EZRIN, RPE65, DCT, TYR, TYRP, MITF, PMEL), early photoreceptors (PRs) (coexpressing CRX and RCVRN), inner nuclear layer neurons (expressing CALB2), and retinal ganglion cells [RGCs, expressing BRN3B and Neurofilament (NF) 200]. Furthermore, we found that retinal progenitors divide at the apical side of the hESC-derived retinal tissue (next to the RPE layer) and then migrate toward the basal side, similar to that found during embryonic retinogenesis. We detected synaptogenesis in hESC-derived retinal tissue, and found neurons containing many synaptophysin-positive boutons within the RGC and PR layers. We also observed long NF200-positive axons projected by RGCs toward the apical side. Whole-cell recordings demonstrated that putative amacrine and/or ganglion cells exhibited electrophysiological responses reminiscent of those in normal retinal neurons. These responses included voltage-gated Na(+) and K(+) currents, depolarization-induced spiking, and responses to neurotransmitter receptor agonists. Differentiation in adherent conditions allows generation of long and flexible pieces of 3D retinal tissue suitable for isolating transplantable slices of tissue for retinal replacement therapies.