Endocytoscopic visualization of squamous cell islands within Barrett's epithelium.

AIM: To study the endocytoscopic visualization of squamous cell islands within Barrett's epithelium. METHODS: Endocytoscopy (ECS) has been studied in the surveillance of Barrett's esophagus, with controversial results. In initial studies, however, a soft catheter type endocytoscope was used, while only methylene blue dye was used for the staining of Barrett's mucosa. Integrated type endocytoscopes (GIF-Q260 EC, Olympus Corp, Tokyo, Japan) have been recently developed, with the incorporation of a high-power magnifying endocytoscope into a standard endoscope together with narrow-band imaging (NBI). Moreover, double staining with a mixture of 0.05% crystal violet and 0.1% of methylene blue (CM) during ECS enables higher quality images comparable to conventional hematoxylin eosin histopathological images. RESULTS: In vivo endocytoscopic visualization of papillary squamous cell islands within glandular Barrett's epithelium in a patient with long-segment Barrett's esophagus is reported. Conventional white light endoscopy showed typical long-segment Barrett's esophagus, with small squamous cell islands within normal Barrett's mucosa, which were better visualized by NBI endoscopy. ECS after double CM staining showed regular Barrett's esophagus, while higher magnification (× 480) revealed the orifices of glandular structures better. Furthermore, typical squamous cell papillary protrusion, classified as endocytoscopic atypia classification (ECA) 2 according to ECA, was identified within regular glandular Barrett's mucosa. Histological examination of biopsies taken from the same area showed squamous epithelium within glandular Barrett's mucosa, corresponding well to endocytoscopic findings. CONCLUSION: To our knowledge, this is the first report of in vivo visualization of esophageal papillary squamous cell islands surrounded by glandular Barrett's epithelium.

Training in peroral endoscopic myotomy (POEM) for esophageal achalasia.

Peroral endoscopic myotomy (POEM) has been developed in the context of natural orifice transluminal endoscopic surgery (NOTES) as a minimally invasive endoscopic treatment for symptomatic esophageal achalasia, which is a chronic progressive benign disease with severe morbidity and difficult management. Since September 2008, POEM has been successfully performed in more than 200 consecutive patients with symptomatic achalasia at the Digestive Disease Center of Showa University, Northern Yokohama Hospital, Yokohama, Japan, with excellent short- and long-term results and absence of serious complications. International experience of POEM within clinical studies is also promising. According to these results, POEM is considered as a safe procedure that can be applied to all achalasia patients. However, the low incidence of achalasia (0.3%-1% per 100,000 population), in combination with the potential serious complications related to the technically demanding POEM procedure, has made training difficult. There is therefore an urgent need for an animal model for training to decrease the learning curve. Further, there are other ethical and training issues to address. The pig is the most appropriate animal model for training in POEM due to its anatomy being similar to that of humans. The porcine esophagus has the advantage of easy mobilization due to absence of tight junctions to surrounding organs. A non-survival porcine model would be a simple, inexpensive, and reproducible animal model for training in POEM, without the need for concern about complications. A possible training process might first involve observation of POEM performed by specialists, then training on non-survival and survival porcine models, followed by training in humans under specialist guidance and finally, performance of POEM in humans.

Endoscopic mucosal resection, endoscopic submucosal dissection, and beyond: full-layer resection for gastric cancer with nonexposure technique (CLEAN-NET).

Mucosal cancer in the gastrointestinal tract generally has low risk of lymph node metastasis. Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are techniques of local excision of neoplasia confined to the mucosal layer. Specimens from EMR/ESD contribute to several diagnoses, and histologic results affect treatment decisions. A combined laparoscopic and endoscopic approach to neoplasia with a nonexposure technique allows full-thickness resection of the stomach wall without exposing the gastric lumen to the peritoneal cavity, preventing cancer cell dissemination to the peritoneal cavity. This article reviews EMR/ESD and describes a new full-thickness resection method using the nonexposure technique (CLEAN-NET).

Clinicopathological characteristics and treatment strategies in early gastric cancer: a retrospective cohort study.

BACKGROUND: Both endoscopic and surgical approaches are employed in the treatment of early gastric cancer (EGC). The aim of this study was to establish appropriate treatment strategies for early gastric cancer. METHODS: We retrospectively examined clinicopathological data of EGC patients who had undergone surgery. RESULTS: A total of 327 patients (204 males and 123 females, mean age 63.2 years) were eligible for inclusion in the study. The median follow-up period was 31 months. Of 161 mucosal (pT1a) tumors, 87 were mainly undifferentiated and 110 had an undifferentiated component. Four patients with pT1a tumors had lymph node metastases; all these tumors were signet-ring cell carcinomas and were macroscopic type 0-IIc with ulceration, and only one of them had lymphatic invasion. Among patients with submucosal tumors, four of 43 patients with pT1b1 tumors and 37 of 123 patients with pT1b2 tumors had nodal metastases. Lymph node metastases were significantly higher in mixed undifferentiated type group than differentiated type group for both groups, pT1a-pT1b1 (p = 0.0251) and pT1b2 (p = 0.0430) subgroups. Only four of 45 patients with nodal metastases were diagnosed preoperatively by computed tomography (sensitivity 8.9%, specificity 96.2%). Nine patients with pT1b tumors had recurrence after surgery, and died. The sites of initial recurrence were liver, bone, peritoneum, distant nodes, and the surgical anastomosis. CONCLUSIONS: The incidence of nodal metastases was approximately 5% in undifferentiated type mucosal (pT1a) tumors, and higher in submucosal (pT1b) tumors. The sensitivity of preoperative diagnosis of nodal metastases in EGC using computed tomography was relatively low in this study. Therefore at present surgery with adequate lymphadenectomy should be performed as curative treatment for undifferentiated type EGC.

Peroral endoscopic myotomy for esophageal achalasia: technique, indication, and outcomes.

Peroral endoscopic myotomy (POEM) has been developed as an incisionless, minimally invasive endoscopic treatment intending a permanent cure for esophageal achalasia. The concept of endoscopic myotomy was first reported about 3 decades ago, but the direct incision method through the mucosal layer was not considered to be a safe and reliable approach. A novel method of endoscopic myotomy was developed and established by the authors. In this article, the current techniques, applications, and clinical results of POEM are described.

Clinical usefulness of pit patterns for detecting colonic lesions requiring surgical treatment.

BACKGROUND: The number of patients suffering from colorectal cancer is increasing. According to Japanese guidelines, lesions with a submucosal invasive depth >1,000 µm should be treated with radical proctocolectomy. We propose and evaluate a new clinical classification for pit patterns that uses endoscopy to assess lesion depth for determination of the appropriate therapeutic approach for early colorectal cancers and adenomas. METHODS: Endoscopic images of colorectal adenomas and early cancer cases with type V(I) pit pattern, resected surgically or endoscopically from April 2002 to April 2007 at Showa University Yokohama Northern Hospital, were utilized for analysis. Each image was retrospectively analyzed for (A) pit narrowness, (B) irregular pit margins, and (C) indistinct stromal staining. Sensitivity, specificity, and predictive value were evaluated as major outcomes, using pathological results as the standard. RESULT: In total, 186 cases were assessed. With all features considered (A, B, and C), the sensitivity, specificity, and positive and negative predictive values were 47.8%, 86.3%, 66.0%, and 74.2%, respectively. When limited to two features (A and B), these values were 75.3%, 81.2%, 70.2%, and 84.8%, respectively. CONCLUSION: Our results suggest that the established criteria can, to a certain degree, distinguish between high and low irregularity in colorectal lesions with V(I) pit pattern indicating submucosal cancer infiltration of more or less than 1,000 µm with the clinical consequence of surgery versus endoscopic mucosal resection/endoscopic mucosal dissection.