Ryusuke Kimura

Endocytoscopy is a promising modality with high diagnostic accuracy for gastric cancer.

BACKGROUND AND STUDY AIM Endocytoscopy (ECS) enables in vivo microscopic imaging, which allows analysis of mucosal structures at the cellular level; however, limited data are available on the validity of ECS in the stomach. The aim of this study was to evaluate the feasibility of ECS in the diagnosis of early gastric cancer. PATIENTS AND METHODS Gastric lesions that were the targets of histopathological diagnosis by endoscopic submucosal dissection or biopsy specimen were prospectively enrolled and evaluated using a single charge-coupled device-integrated endocytoscope, following double staining with crystal violet and methylene blue. High grade ECS atypia was defined according to specific irregularities in gland structure and cell nuclei. The primary end point was the accuracy of ECS diagnosis for gastric cancer, using histopathological diagnosis as the gold standard. RESULTS A total of 82 lesions were investigated, including 23 early gastric cancers, 10 gastric adenomas, and 49 non-neoplastic lesions. Ten lesions could not be clearly observed by ECS because of poor staining due to viscous mucus or plaque; thus, assessability rates with ECS were 88 % in total and 91 % for gastric cancer. High grade ECS atypia was observed in 86 % of assessable gastric cancers, but not in any cases of gastric adenomas or non-neoplastic lesions. The sensitivity, specificity, positive and negative predictive values of high grade ECS atypia as the criterion for the diagnosis of gastric cancer were 86 %, 100 %, 100 %, and 94 %, respectively. No serious complications occurred during or after the examinations. CONCLUSION ECS is a clinically feasible modality to obtain in vivo histology, with high diagnostic accuracy in gastric cancer.

Delayed bleeding after endoscopic submucosal dissection for non-ampullary superficial duodenal neoplasias might be prevented by prophylactic endoscopic closure: Analysis of risk factors

Duodenal endoscopic submucosal dissection (ESD) is technically challenging because of anatomical specificities and, to date, has not been validated concerning the high rate of complications such as perforation and delayed bleeding. In the present study, the risk factors for delayed bleeding after duodenal ESD are presented with the goal of establishing preventive measures.

Accuracy and concordance of endocytoscopic atypia for the diagnosis of gastric cancer.

BACKGROUND AND AIM High-grade atypia demonstrated by endocytoscopy may be a key criterion for the diagnosis of gastric cancer. We therefore sought to verify whether endocytoscopic atypia can provide satisfactory levels of diagnostic accuracy and concordance among trainee and expert endoscopists. METHOD A total of 100 lesions evaluated by endocytoscopy and histopathology were enrolled to create an endocytoscopic image catalog (44 early cancers, 10 low-grade adenomas, 46 non-neoplastic lesions). Four endoscopists (two trainees and two experts) independently reviewed the catalog images and evaluated each of them for the presence or absence of endocytoscopic atypia. High-grade endocytoscopic atypia, as a criterion for cancer diagnosis, was defined as the consistent observation of any of the following features: lumen absence, lumen fusion, and irregular nuclei showing the three typical features (heterogeneous shape, swelling, and disarrangement). RESULTS High-grade endocytoscopic atypia was observed in 78 %, 18 %, and 4 % of cancers, adenomas, and non-neoplastic lesions, respectively. The sensitivity, specificity, accuracy, and positive and negative predictive values for cancer diagnosis by endocytoscopy were 78.4 %, 93.3 %, 87.3 %, 85.4 %, and 87.3 %, respectively. The concordance rate for the results of high-grade endocytoscopic atypia was good among the four endoscopists (κ value 0.682). No significant difference in diagnostic accuracy or concordance was observed between trainee and expert endoscopists. CONCLUSION Using the defined high-grade atypia as a diagnostic criterion of cancer, endocytoscopy provided a satisfactory level of accuracy and concordance for the diagnosis of early gastric cancer, regardless of endoscopic expertise.

Desmoplastic reaction in biopsy specimens of early colorectal cancer: A Japanese prospective multicenter study

We previously reported that detection of desmoplastic reaction (DR) in pretreatment biopsy specimens was useful for predicting the depth of submucosal invasion (SM depth) in nonpedunculated early colorectal cancers (ECRCs) in a retrospective study. Here, we performed a prospective multicenter study for verification of our previous findings. Subjects were diagnosed with ECRC by endoscopy, and with adenocarcinoma from the biopsy specimens. Eleven institutions affiliated with the Japanese Society for Cancer of the Colon and Rectum participated in this collaborative study. A total of 112 patients with ECRC were enrolled. For nonpedunculated ECRCs, presence of DR was significantly correlated with SM depth. The sensitivity and specificity of detection of DR for prediction of pSM2 (tumor invasion ≥1000 µm) in nonpedunculated ECRCs were 68.6% and 92.0%, respectively. Evaluation of DR in pretreatment biopsy specimens may be useful for the clinicopathological diagnosis of colorectal carcinoma with massive invasion into the submucosal layer.

Clinicopathological Features of Serrated Adenocarcinoma Defined by Mäkinen in Dukes' B Colorectal Carcinoma

Objective: Serrated adenocarcinoma (SAC), proposed as a new pathologic type, arises predominantly in the right side of the colon and has a poorer prognosis than conventional colorectal carcinoma. The prognosis of colorectal carcinoma is variable in Dukes’ B, so the aim of this study was to determine whether or not SAC has a poor prognosis in Dukes’ B. Methods: The study group comprised 64 patients who underwent surgery for colorectal carcinoma. We undertook a statistical analysis of the association of SAC and non-SAC with sex, age, histologic type, depth of tumor, location of tumor, venous invasion and lymphatic invasion. Results: SACs were encountered in 17.5% of cases (n = 11). SAC had a less favorable 5-year survival than non-SAC (p = 0.0396 log-rank, Kaplan-Meier). The factors that achieved statistical significance in the univariate analysis were subsequently included in a multivariate analysis and we found that SAC was an independent factor (p = 0.027). Conclusions: SAC has a poor prognosis and is not affected by other factors confirming that SAC is an independently less favorable prognostic factor.

A new device for simultaneous manipulation of an endoscope and a treatment device during procedures: an ex vivo animal study.

BACKGROUND AND STUDY AIMS Endoscopists must maneuver both endoscope and treatment device during procedures, requiring them to release their hand from the scope to manipulate the treatment device. Aiming to improve this situation, we developed a new device called the Thumb Drive. PATIENTS AND METHODS The Thumb Drive comprises a controller and catheter. After attaching the controller to the endoscopes grip, the catheter is inserted into the forceps channel. The treatment device is then inserted into the Thumb Drive and fixed with its tip protruding from the endoscope tip. A single endoscopist resected 10 lesions in a porcine stomach by endoscopic submucosal dissection (ESD) using the Thumb Drive. RESULTS All lesions were resected en bloc using this new device without any perforations. The mean incision, dissection, and operative times were 97.2 ± 48.7 seconds, 121.6 ± 53.6 seconds, and 218.8 ± 67.8 seconds, respectively. CONCLUSIONS The Thumb Drive enables the endoscopist to manipulate the treatment device with the thumb while handling the endoscope with the right hand during ESD. Its utility should be examined in in vivo studies as a next step.

Ex vivo comparison study of smart Shooter®, a new endoscopic device for safe and speedy treatment.

Background: In many endoscopic procedures, the operative view can be compromised when manipulating the treatment device because the endoscopists must release their hand from the endoscope. We have developed a new device called the Smart Shooter® (SS) for simultaneous manipulation of the endoscope and treatment device, and evaluated the utility of the SS compared with the conventional method. Methods: The SS is a semirigid, loop-shaped channel extender that enables endoscopists to manipulate the treatment device with the thumb of the right hand while holding the endoscope with the same hand. We conducted a comparative study of gastric endoscopic submucosal dissection (ESD) and esophageal injection sclerotherapy (EIS) in a porcine model to compare the utility of the SS method with the conventional method. Results: In gastric ESD, all lesions were resected en bloc with no perforation. The mean operative time was significantly shorter with the SS method than with the conventional method (287.5 ± 155.4 vs. 403.5 ± 215.6 s, p = 0.04). In esophageal EIS, 4 paravenous injections were given with the SS method and 5 were given using the conventional method. Similarly, the mean operative time was significantly shorter with the SS method than with the conventional method (19.0 ± 7.8 vs. 23.8 ± 10.0 s, p = 0.04). Conclusion: Use of the SS enabled a shorter operative time for gastric ESD and esophageal EIS with no adverse events. The present results suggest that the SS can contribute to safe and speedy endoscopic treatment.

Feasibility of a Newly Developed Thumb Control Device for Simultaneous Manipulation of the Endoscope and Treatment Devices in Endoscopic Submucosal Dissection: A Clinical Feasibility Study

Background/Aim: We developed a new device for the simultaneous manipulation of an endoscope and treatment devices, which we named the Smart Shooter®. The aim of this study was to validate the feasibility of using the Smart Shooter® in endoscopic submucosal dissection (ESD). Methods: This pilot feasibility study conducted between March and June 2014 involved 20 consecutive patients who underwent ESD for superficial gastrointestinal neoplasia. The primary endpoint was a serious adverse event during the ESD procedure. The secondary endpoints were completion rate of ESD using the Smart Shooter® and a mechanical problem with the Smart Shooter® during ESD. Results: A total of 20 patients underwent ESD for 23 lesions: 5 pharyngeal, 8 esophageal, 7 gastric, and 3 colonic lesions. There were no serious adverse events or mechanical problems during ESD. The completion rate of ESD using the Smart Shooter® was 82.6% (19/23). Conclusion: ESD using the Smart Shooter® appears to be technically feasible. Clinical trial registration: UMIN 000013710.