Multicenter prospective study on the histological diagnosis of gastric cancer by narrow band imaging-magnified endoscopy with and without acetic acid

Background and study aims  The usefulness of endoscopy for diagnosing histological type remains unclear. This study aimed to examine the diagnostic accuracy of white light endoscopy (WLE), magnified endoscopy with narrow band imaging (NBI-ME), and NBI-ME with acetic acid enhancement (NBI-AA) for histological type of gastric cancer. Patients and methods  Patients with depressed-type gastric cancers resected by endoscopic submucosal dissection were prospectively enrolled, and 221 cases were analyzed. Histological type was diagnosed by WLE, followed by NBI-ME and NBI-AA. Histological type was classified into differentiated adenocarcinoma and undifferentiated adenocarcinoma. Histological type was diagnosed based on lesion color in WLE, surface patterns (pit, villi, and unclear) and vascular irregularities in NBI-ME, and surface patterns in NBI-AA. Results  Histological types of target areas were differentiated adenocarcinoma and undifferentiated adenocarcinoma in 206 and 15 cases, respectively. Diagnostic accuracy of WLE, NBI-ME, and NBI-AA for the histological type was 96.4 % (213/221), 96.8 % (214/221), and 95.5 % (211/221), respectively. No significant differences were observed among modalities. Positive predictive value based on endoscopic findings in NBI-ME was 98.0 % (149/152) for the villi pattern, 100 % (19/19) for the irregular pit pattern, 100 % (9/9) for the unclear surface pattern with a vascular network, 90.3 % (28/31) for the unclear surface pattern with mild vascular irregularity, and 88.9 % (8/9) for the unclear surface pattern with severe vascular irregularity. Conclusions  NBI-ME and NBI-AA did not show any advantages over WLE for diagnostic accuracy. Villi pattern, irregular pit pattern, and vascular network may be useful for identifying differentiated adenocarcinoma.

Multiple Re-entry Closures After TEVAR for Ruptured Chronic Post-dissection Thoraco-abdominal Aortic Aneurysm

Introduction

Although thoracic endovascular aortic repair (TEVAR) has become a promising treatment for complicated acute type B dissection, its role in treating chronic post-dissection thoraco-abdominal aortic aneurysm (TAA) is still limited owing to persistent retrograde flow into the false lumen (FL) through abdominal or iliac re-entry tears.

Report

A case of chronic post-dissection TAA treatment, in which a dilated descending FL ruptured into the left thorax, is described. The primary entry tear was closed by emergency TEVAR and multiple abdominal re-entries were closed by EVAR. In addition, major re-entries at the detached right renal artery and iliac bifurcation were closed using covered stents. To close re-entries as far as possible, EVAR was carried out using the chimney technique, and additional aortic extenders were placed above the coeliac artery. A few re-entries remained, but complete FL thrombosis of the rupture site was achieved. Follow-up computed tomography showed significant shrinkage of the FL.

Discussion

In treating post-dissection TAA, entry closure by TEVAR is sometimes insufficient, owing to persistent retrograde flow into the FL from abdominal or iliac re-entries. Adjunctive techniques are needed to close these distal re-entries to obtain complete FL exclusion, especially in rupture cases. Recently, encouraging results of complete coverage of the thoraco-abdominal aorta with fenestrated or branched endografts have been reported; however, the widespread employment of such techniques appears to be limited owing to technical difficulties. The present method with multiple re-entry closures using off the shelf and immediately available devices is an alternative for the endovascular treatment of post-dissection TAA, especially in the emergency setting.

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A case of ruptured post-dissection thoraco-abdominal aneurysm was treated.

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Following entry closure by TEVAR, EVAR was performed to close multiple re-entries.

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Re-entries at the renal artery ostium and iliac artery were closed by covered stents.

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Complementary re-entry closure techniques are essential to treat false lumen rupture.

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This report demonstrates successful re-entry closure techniques following TEVAR.

Evaluation of an e-learning system for diagnosis of gastric lesions using magnifying narrow-band imaging: a multicenter randomized controlled study

Background and study aim Magnifying narrow-band imaging (M-NBI) is useful for the accurate diagnosis of early gastric cancer (EGC). However, acquiring skill at M-NBI diagnosis takes substantial effort. An Internet-based e-learning system to teach endoscopic diagnosis of EGC using M-NBI has been developed. This study evaluated its effectiveness. Participants and methods This study was designed as a multicenter randomized controlled trial. We recruited endoscopists as participants from all over Japan. After completing Test 1, which consisted of M-NBI images of 40 gastric lesions, participants were randomly assigned to the e-learning or non-e-learning groups. Only the e-learning group was allowed to access the e-learning system. After the e-learning period, both groups received Test 2. The analysis set was participants who scored < 80 % accuracy on Test 1. The primary end point was the difference in accuracy between Test 1 and Test 2 for the two groups. Results A total of 395 participants from 77 institutions completed Test 1 (198 in the e-learning group and 197 in the non-e-learning group). After the e-learning period, all 395 completed Test 2. The analysis sets were e-learning group: n = 184; and non-e-learning group: n = 184. The mean Test 1 score was 59.9 % for the e-learning group and 61.7 % for the non-e-learning group. The change in accuracy in Test 2 was significantly higher in the e-learning group than in the non-e-learning group (7.4 points vs. 0.14 points, respectively; P < 0.001). Conclusion This study clearly demonstrated the efficacy of the e-learning system in improving practitioners' capabilities to diagnose EGC using M-NBI.Trial registered at University Hospital Medical Information Network Clinical Trials Registry (UMIN000008569).

Surgical strategy of esophageal resection and reconstruction for aortoesophageal fistula

Aortoesophageal fistula is a critical and life-threatening disease. The cardiovascular strategy for graft replacement has been widely discussed. However, the surgical strategy of esophageal resection and reconstruction for aortoesophageal fistula has rarely been discussed. The objective of this study is to establish a surgical strategy and procedure of esophageal resection and reconstruction for aortoesophageal fistula. Eleven patients with aortoesophageal fistula who underwent aortic graft replacement and esophagectomy between 2008 and 2015 at Kobe University Hospital were enrolled in this study. Patient characteristics, operative methods, and clinical outcomes were obtained by retrospective chart review. All 11 patients underwent graft replacement, esophagectomy, and omental wrapping. Ten esophagectomies were simultaneously accomplished in the same operative field as aortic graft replacement. Seven patients underwent subtotal esophagectomy from a left thoracotomy, and three patients underwent upper hemiesophagectomy from a median sternotomy. The other patient underwent staged esophagectomy from a right thoracotomy. Seven of 11 patients (63.6%) successfully underwent staged esophageal reconstruction. Pedicled jejunal transfer with supercharge and superdrainage were performed in six patients, and ileocecal reconstruction was performed in one patient. Median survival time in the patients with esophageal reconstruction was 21 months while that in the patients without esophageal reconstruction was 10 months. Six of 7 patients (85.7%) who underwent esophageal reconstructions were alive. Our surgical strategy for aortoesophageal fistula, which includes simultaneous graft replacement and esophagectomy in the same operative field and staged reconstruction by pedicled jejunal transfer to ensure omental wrapping, is feasible and promising.

Perforation and postoperative bleeding of endoscopic submucosal dissection in gastric tumors: analysis of 1190 lesions in low- and high-volume centers in Saga, Japan

BACKGROUND

This retrospective study aimed to determine risk factors associated with serious complications of endoscopic submucosal dissection of gastric tumors in multicenters compared between high- and low-volume centers.

METHODS

Between 2001 and 2010, gastric endoscopic submucosal dissection was performed in 1190 lesions of 1082 patients in five hospitals in Saga, three high-volume and two low-volume centers. Risk factors for serious complications were evaluated. Patients' background characteristics were evaluated, including anticoagulants use and underlying diseases.

RESULTS

Postoperative bleeding was detected in 75 patients (6.9%), and perforation was detected in 40 patients (3.7%). Most postoperative bleeding and perforation cases were recovered with endoscopic procedures, although one case of each complication was treated by emergency surgery. Multivariate analysis indicated that risk factors for perforation were tumor location, massive submucusal invasion, endoscopists' experience of 100-149 cases and hypertension, and that risk factors for postoperative bleeding were tumor location, resected tumor size, and scar lesion. The serious complications were not different between high- and low-volume centers.

CONCLUSIONS

The present study indicated that risk factors for perforation during endoscopic submucosal dissection were tumor, endoscopist and patient related, although risk factors for postoperative bleeding were tumor related. There was no difference in complications between high- and low-volume centers.

Two years' intensive training in endoscopic diagnosis facilitates detection of early gastric cancer

OBJECTIVE

Early detection of gastric cancer by screening endoscopy facilitates endoscopic treatment in place of open surgery. The aim of this study was to evaluate whether 2 years intensive training improved the detection of gastric cancer by screening endoscopy.

METHODS

An endoscopist who had trained for 6 years as a general physician, performed screening endoscopy at Imari Arita Kyoritsu Hospital before (group I) and after (group II) intensive training in the diagnosis of early gastric cancer in consecutive patients.

RESULTS

Background characteristics, including age (61.6 vs. 62.2 years) and sex, did not differ between the groups. Before training, 10 gastric neoplasms were detected in 937 patients in group I: four early gastric cancers, one gastric adenoma, and five advanced gastric cancer. After training, 36 gastric neoplasms were detected in 937 patients in group II: 18 early gastric cancers, 11 gastric adenoma, five advanced gastric cancer, and one each of gastric carcinoid and malignant lymphoma. The detection rate for early gastric cancer was significantly improved by training [group I: 4/937 (0.4%) vs. group II: 18/937 (1.9%)], although the detection rate for advanced gastric cancer did not differ before and after training. The proportion of early gastric cancer + adenoma to advanced cancer was higher in group II (5/5 vs. 29/5 in group I).

CONCLUSION

Intensive training in upper gastrointestinal endoscopy screening dramatically improved the detection rate for early gastric cancer, although the detection rate for advanced gastric cancer was not affected.

Colorectal cancer screening with odour material by canine scent detection

OBJECTIVE

Early detection and early treatment are of vital importance to the successful treatment of various cancers. The development of a novel screening method that is as economical and non-invasive as the faecal occult blood test (FOBT) for early detection of colorectal cancer (CRC) is needed. A study was undertaken using canine scent detection to determine whether odour material can become an effective tool in CRC screening.

DESIGN

Exhaled breath and watery stool samples were obtained from patients with CRC and from healthy controls prior to colonoscopy. Each test group consisted of one sample from a patient with CRC and four control samples from volunteers without cancer. These five samples were randomly and separately placed into five boxes. A Labrador retriever specially trained in scent detection of cancer and a handler cooperated in the tests. The dog first smelled a standard breath sample from a patient with CRC, then smelled each sample station and sat down in front of the station in which a cancer scent was detected.

RESULTS

33 and 37 groups of breath and watery stool samples, respectively, were tested. Among patients with CRC and controls, the sensitivity of canine scent detection of breath samples compared with conventional diagnosis by colonoscopy was 0.91 and the specificity was 0.99. The sensitivity of canine scent detection of stool samples was 0.97 and the specificity was 0.99. The accuracy of canine scent detection was high even for early cancer. Canine scent detection was not confounded by current smoking, benign colorectal disease or inflammatory disease.

CONCLUSIONS

This study shows that a specific cancer scent does indeed exist and that cancer-specific chemical compounds may be circulating throughout the body. These odour materials may become effective tools in CRC screening. In the future, studies designed to identify cancer-specific volatile organic compounds will be important for the development of new methods for early detection of CRC.

Continuous monitoring of nitric oxide release induced by cholecystokinin from the choledochal sphincter in guinea pigs

BACKGROUND/AIMS

Many in vitro studies in the choledochoduodenal junction of the guinea pig have shown that cholecystokinin (CCK) contracts the sphincter of Oddi (SO). This study, using the choledochal sphincter of the guinea pig as the SO, evaluates the hypothesis that effects of CCK on the SO were mediated by nitric oxide (NO).

METHODS

Spontaneous motility and effects of CCK on the choledochal sphincter were recorded using a constant-perfusion technique, and direct measurement of NO release using a specific NO sensor was performed at the same time.

RESULTS

CCK-8 decreased the phasic wave amplitude of the choledochal sphincter, and increased NO release. N(G)-L-arginine-methyl-ester (L-NAME), an inhibitor of NO synthase, increased the spontaneous motility and converted the CCK-induced inhibitory response into an excitatory response. L-NAME also reduced NO release and abolished the increase of NO that had been caused by CCK-8. These effects were reduced by treatment with L-arginine (L-Arg). L-Arg application enhanced NO release, and recovered the increase of NO by CCK-8.

CONCLUSION

These studies demonstrate that CCK relaxes the choledochal sphincter and this relaxant response is mediated by NO.

Nitric oxide mediates cerulein-induced relaxation of canine sphincter of Oddi

This study evaluates the hypothesis that cerulein relaxes the sphincter of Oddi (SO) via nitric oxide (NO). The spontaneous motility and the response to cerulein on the canine SO were recorded using a constant-perfusion technique. N(G)-L-arginine-methyl-ester (L-NAME) increased the spontaneous motility and dose-dependently reduced the cerulein-induced inhibitory response of the SO. After treatment with L-NAME at higher doses, cerulein induced an excitatory response. This effect was reversed by treatment with excess L-arginine. Similar results were obtained using cholecystokinin octapeptide in place of cerulein. In separate studies, cerulein generated increases in intracellular cAMP and cGMP levels in the SO. This indicates that the intracellular mechanism mediating cerulein-induced relaxation involves the production of cAMP and cGMP. On the other hand, treatment with L-NAME absorbed the increase in cAMP and cGMP levels by cerulein. These studies demonstrate that cerulein relaxes the canine SO mainly via NO, increasing intracellular cAMP and cGMP levels.