Yasutoshi Ochiai

Usefulness of the DL in ME with NBI for determining the expanded area of early-stage differentiated gastric carcinoma

AIM To investigate whether magnifying endoscopy with narrow band imaging (ME-NBI) is useful for evaluating the area of superficial, depressed- or flat-type differentiated adenocarcinoma of the stomach. METHODS This procedure was performed in Saitama Medical University International Medical Center, Japanese Red Cross Kumamoto Hospital and Kitakyushu Municipal Medical Center. The subjects were 31 patients in whom biopsy findings, from superficial, depressed- or flat-type gastric lesion, suggested differentiated adenocarcinoma in the above 3 hospitals between January and December 2009. Biopsy was performed on the lesion and non-lesion sides of a boundary (imaginary boundary) visualized on ME-NBI. The results were pathologically investigated. We evaluated the accuracy of estimating a demarcation line (DL) on ME-NBI in comparison with biopsy findings as a gold standard. RESULTS The DL that could be recognized at 2 points on the orifice and anal sides of each lesion during ME-NBI was consistent with the pathological findings in 22 patients with 0-IIc lesions, 7 with 0-IIb lesions, and 2 with 0-IIb + IIc lesions, showing an accuracy of 100%. CONCLUSION The results suggest the usefulness of ME-NBI for evaluating the area of superficial, depressed- and flat-type differentiated adenocarcinoma of the stomach.

Accuracy of biopsy for the preoperative diagnosis of superficial nonampullary duodenal adenocarcinoma

BACKGROUND AND AIMS Endoscopic biopsy sampling for the diagnosis of duodenal adenocarcinoma is not perfect. We investigated the accuracy of biopsy specimen diagnoses of superficial nonampullary duodenal epithelial tumors (NADETs). METHODS Clinicopathologic data were retrospectively reviewed for 95 superficial NADETs from 95 patients who underwent endoscopic resection. Preoperative diagnoses based on biopsy specimens were compared with histologic diagnoses of resected specimens. RESULTS Among the 21 lesions with biopsy specimen diagnoses of carcinoma, 12 (57.1%) were histologically diagnosed as adenomas after resection. Among the 74 lesions with biopsy specimen diagnoses of adenoma, 15 (20.3%) were histologically diagnosed as carcinomas after resection. The duodenal biopsy specimen predicted final histologic diagnoses of carcinoma with a sensitivity of 37.5% (95% CI, 18.8-59.4), specificity of 83.1% (95% CI, 72.3-91.0), accuracy of 71.6% (95% CI, 61.4-80.4), positive predictive value of 42.9% (95% CI, 21.8-66.0), and negative predictive value of 79.7% (95% CI, 68.8-88.2). Among 61 cases considered suitable for EMR, treatment modality was converted from EMR to endoscopic submucosal dissection because of the nonlifting sign in 15 cases (24.6%). CONCLUSIONS The accuracy of duodenal biopsy sampling was relatively low. Duodenal biopsy sampling may induce unexpected fibrosis. New endoscopic modalities that can improve preoperative diagnosis yield of NADETs are eagerly awaited.

A case of gastric mucosa-associated lymphoid tissue lymphoma in which magnified endoscopy with narrow band imaging was useful in the diagnosis

Recently, we reported a case of gastric mucosa-associated lymphoid tissue (MALT) lymphoma presenting with unique vascular features. In the report, we defined the tree-like appearance (TLA) on the images of abnormal blood vessels which resembled branches from the trunk of a tree in the shiny mucosa, in which the glandular structure was lost. The 67-year-old female was diagnosed with gastric MALT lymphoma. The patient received eradication therapy for H. pylori. Conventional endoscopy revealed multiple ill-delineated brownish depressions in the stomach and cobblestone-like mucosa was observed at the greater curvature to the posterior wall of the upper gastric body 7 mo after successful eradication. Unsuccessful treatment of gastric MALT lymphoma was suspected on conventional endoscopy. Conventional endoscopic observations found focal depressions and cobblestone-like appearance, and these lesions were subsequently observed using magnified endoscopy combined with narrow band imaging to identify abnormal vessels presenting with a TLA within the lesions. Ten biopsies were taken from the area where abnormal vessels were present within these lesions. Ten biopsies were also taken from the lesions without abnormal vessels as a control. A total of 20 biopsy samples were evaluated to determine whether the diagnosis of MALT lymphoma could be obtained histologically from each sample. A positive diagnosis was obtained in 8/10 TLA (+) sites and in 2/10 TLA(-) sites. Target biopsies of the site with abnormal blood vessels can potentially improve diagnostic accuracy of gastric MALT lymphoma.

Effects of carbon dioxide insufflation in balloon-assisted enteroscopy: A systematic review and meta-analysis

Background and aim The efficacy of CO2 insufflation during balloon-assisted enteroscopy remains controversial. This study aimed to perform a systematic review with meta-analysis of randomized controlled trials (RCTs) in which CO2 insufflation was compared with air insufflation in balloon-assisted enteroscopy. Methods PubMed, the Cochrane library, and the Igaku-Chuo-Zasshi database were searched to identify RCTs eligible for inclusion in the systematic review. Data from the eligible studies were combined to calculate the pooled odds ratios (ORs) or weighted mean differences (WMDs) with 95% confidence intervals (CIs). Results Four RCTs (461 patients) were identified. Compared with air insufflation, CO2 insufflation significantly increased intubation depth of oral enteroscopy (WMD: 55.2, 95% CI: 10.77–99.65, p = 0.015). However, there was significant heterogeneity. The intubation depth of anal enteroscopy showed no significant difference between the CO2 group and the air group. CO2 insufflation significantly reduced abdominal pain compared with air insufflation (WMD: −2.463, 95% CI: −4.452 to −0.474, p = 0.015), without significant heterogeneity. The PaCO2 or end-tidal CO2 level showed no significant difference between the CO2 group and air group. Conclusions Compared with air insufflation, CO2 insufflation during balloon-assisted enteroscopy caused less post-procedural pain without CO2 retention.

Which part of a porcine stomach is suitable as an animal training model for gastric endoscopic submucosal dissection

BACKGROUND AND STUDY AIMS Training using an animal model is generally recommended before performing endoscopic submucosal dissection (ESD) in humans. This study aimed to clarify the suitability of an isolated porcine stomach as an animal training model for gastric ESD. MATERIALS AND METHODS Study 1: six experienced endoscopists performed ESDs of six simulated lesions located in six locations in an isolated porcine stomach (1, lower third [L]/ greater curvature [Gre]; 2, L/ anterior wall [Ant]; 3, L/ posterior wall [Post]; 4, upper third [U]/ Gre; 5, U/Ant; 6, U/Post). The procedure times (s/cm(2)) were compared among the different lesion locations. A questionnaire (scored 1 - 5) completed by the endoscopists was used to assess the difference in the difficulty compared to the human stomach of the three steps of the ESD procedure (injection, incision and dissection). Study 2: the thicknesses of the mucosal layers were histologically evaluated among the six locations in three porcine and two human stomachs. RESULTS Study 1: the procedure speed was significantly slower at L/Gre and U/Gre in the porcine stomachs (P = 0.0004). The questionnaire responses revealed a tendency toward similarity between the lower regions of the human and porcine stomachs at L/Ant, L/Post, U/Ant and U/Post during the dissection step (P = 0.056). In contrast, the injection and incision steps at L/Gre in the porcine stomach were shown to differ in difficultly level (both P = 0.0006). Study 2: the mucosal layers in the porcine stomachs were significantly thicker than those in the human stomachs in the lower areas, especially L/Gre. CONCLUSIONS The difficulty of ESD and the histological features of the porcine stomachs were coincident with those of the human stomachs at L/Ant, L/Post, U/Ant and U/Post. These parts of the porcine stomach may be suitable as animal training models for gastric ESD.

Gastric ESD may be useful as accurate staging and decision of future therapeutic strategy

Background and study aims We sometimes perform gastric endoscopic submucosal dissection (ESD) for total pathologic diagnosis when preoperative diagnosis is difficult. In the present study we analyzed the treatment outcomes and adverse events of diagnostic ESD for early gastric cancer (EGC). Patients and methods We conducted a retrospective analysis of 18 consecutive cases of EGC in 18 patients with a suspected out-of-indication diagnosis who underwent diagnostic ESD, between June 2010 and November 2014. The following parameters were examined: the average length of the longer axis of the lesion; the procedure time; the rates of en bloc resection (ER), complete en bloc resection (CER), and curative resection (CR) as treatment outcomes; and the rates of perforation, delayed bleeding, aspiration pneumonia, disease-related death, and emergency surgery as adverse events. Results The treatment outcomes were as follows: average length of the longer axis of the lesion, 27.4 ± 10.0 mm; procedure time, 87.0 ± 43.1 minutes; ER rate, 18/18 (100.0 %); CER rate, 13/18 (72.2 %); CR rate, 4/18 (22.2 %). CR rate was achieved 37.5 % for the lesions which preoperative diagnosis was more than 30 mm (> 30 mm) in diameter differentiated type with mucosal layer/submucosal layer 1 invasion and ulceration positive. The adverse events (AEs) were perforation in 1 of 18 (5.5 %) patients and delayed bleeding in 1 of 18 (5.5 %). There were no other AEs. Conclusions Diagnostic ESD may be acceptable for future therapeutic strategy when we unconfirmed the pre ESD diagnosis because of lower rate of adverse events and high rate of ER.

“Hold-and-drag” closure technique using repositionable clips for large mucosal defects after colonic endoscopic submucosal dissection

Background and study Aims: To prevent complications after colonic endoscopic submucosal dissection (ESD), we developed a new closure technique using repositionable clips. Patients and methods: The closure of post-ESD mucosal defects was attempted in 19 cases. Mucosal defects were linearly closed by holding and dragging the anal mucosal edge towards the oral mucosal edge using repositionable clips. Standard hemoclips were additionally placed to complete the closure. We retrospectively assessed the feasibility of this technique. Results: Defect closure was successfully completed in 18 cases (94.7 %). The mean defect size and the procedural time were 40.2 ± 12.0 mm (range, 24 – 71 mm) and 10.7 ± 7.2 min (range, 4.0 – 29.9 min), respectively. The mean number of repositionable clips and standard clips required for closure was 1.6 ± 0.8 (range, 1 – 3) and 7.3 ± 3.7 (range, 3 – 16), respectively. No adverse events occurred during procedures and thereafter (95 % confidence interval, 0 – 17.6 %). Conclusions: The new closure technique for large mucosal defects after colonic ESD using repositionable clips was feasible and appeared effective for preventing subsequent adverse events.

Water pressure method for duodenal endoscopic submucosal dissection

Duodenal endoscopic submucosal dissection (ESD) is difficult due to insufficient mucosal elevation, because of the coarse submucosal layer [1]. We report on the “water pressure method” for duodenal ESD. We perform duodenal ESD with a smallcaliber-tip transparent (ST) hood and DualKnifeJ (Olympus, Tokyo, Japan). Insertion of the ST hood under the mucosal flap is a crucial step, as it provides good countertraction to the submucosal layer and good visualization of the operative field. Water pressure by waterjet function of the endoscope helps insertion of the ST hood under the mucosal flap (▶Fig. 1; ▶Video1). Normal saline with a minimum amount of dimethicone is used for the waterjet, rather than water, because normal saline includes electrolytes. With carbon dioxide insufflation, the visual field at the tip of ST hood is small and far. However, water immersion increases the visual field and acts as a magnifier (▶Fig. 2). This improved visualization allows the tissue to be cut more precisely. In conclusion, the “water pressure method” is simple and useful for duodenal ESD.

Endoscopic hand-suturing for defect closure after gastric endoscopic submucosal dissection: a pilot study in animals and in humans

Background and study aims Mucosal suturing enables reliable and optimal defect closure after endoscopic treatments. We developed and investigated the feasibility of endoscopic hand-suturing (EHS) after gastric endoscopic submucosal dissection (ESD) in porcine in vivo models and in human clinical cases. Patients and methods EHS involving continuous suturing of the mucosal layers using a through-the-scope needle-holder and absorbable barbed suture, was performed after gastric ESD in six live pigs and in eight consecutive patients. Success rates, adverse events, and suture maintenance were subsequently investigated. Results EHS was successfully completed in all six pigs and eight patients (100 %) without severe adverse events. However, at 1 week postoperatively the suture closures had not been maintained in all six porcine cases and in the first four clinical cases. In the later four clinical cases, wider and tight suturing of the mucosal edges ensured that the defects remained closed until postoperative week 4. Conclusion EHS is a feasible procedure that may facilitate secure and refined endoscopic surgeries. Mucosal closure in such cases can be maintained using firm suturing.Clinical trial number: UMIN000017125.

Diagnosis of boundary in early gastric cancer.

Endoscopic submucosal dissection (ESD) is an advanced therapeutic endoscopic technique, which allowsresection of larger superficial tumors in the esophagus, stomach, and colon. Precise diagnosis of the boundary between tumor and the non-tumorous surrounding portion is especially important before starting ESD, because too much resection can potentially take more time and can induce a higher complication rate, while too little resection can result in a non-curative resection. The boundary diagnosis is often difficult for early gastric cancer, mainly because of the underlying condition of chronic gastritis. Due to recent developments in endoscopy, including magnified endoscopy and narrow band endoscopy, the boundary diagnosis is becoming easy and more accurate.We have also applied magnified endoscopy combined with narrow band imaging to fresh specimens immediately after resection using thetiling method and XY stage.