Tsuyoshi Sanuki

Retrospective study of technical aspects and complications of endoscopic submucosal dissection for laterally spreading tumors of the colorectum

BACKGROUND AND STUDY AIMS Laterally spreading tumors - non granular type (LST-NG) are more often considered candidates for endoscopic submucosal dissection (ESD) than laterally spreading tumors - granular type (LST-G), because of their higher potential for submucosal invasion. However, ESD for LST-NG can be technically difficult. The aim of our study was to compare our ESD results for LST-NG and for LST-G. PATIENTS AND METHODS Ninety-nine LST-NG and 169 LST-G measuring 20 mm in size or more were removed by ESD. We retrospectively evaluated the clinicopathological features of the tumors and treatment results (en bloc resection rate, procedure time and speed, rate of use of ancillary devices, and complication and recurrence rates). RESULTS Histopathology revealed that there were more submucosally invasive lesions in the LST-NG than in the LST-G group (28 % vs. 9 %; P < 0.0001). The en bloc resection rate, en bloc R0 resection rate, and en bloc curative resection rate of LST-NG were similar to those of LST-G (LST-NG: 99 %, 98 %, and 88 %; LST-G: 99 %, 98 %, and 91 %). In LST-NG, the median procedure time tended to be longer (LST-NG: 69 min; LST-G: 60 min) and the median procedure speed was slower (LST-NG: 0.15 cm (2)/min; LST-G: 0.25 cm (2)/min; P < 0.0001). Use of ancillary devices was higher for LST-NG (38 % vs. 15 % for LST-G; P < 0.0001), as was the perforation rate (5.1 % vs. 0.6 % for LST-G; P = 0.027). No recurrence was seen in either group. CONCLUSIONS ESD was an effective treatment method for both LST-NG and LST-G. However, the degree of technical difficulty appears higher for LST-NG than for LST-G lesions, as shown by the lower dissection speed and higher perforation rate. ESD for LST-NG should probably be performed by those with significant experience of colorectal ESD.

Covered self-expandable metal stents with an anti-migration system improve patency duration without increased complications compared with uncovered stents for distal biliary obstruction caused by pancreatic carcinoma: a randomized multicenter trial.

OBJECTIVES:The requirements of biliary stents used in the palliation of malignant biliary obstruction are a long duration of patency and minimal adverse effects. Covered self-expandable metal stents (SEMSs) have been shown to prevent tumor ingrowth, which is the most frequent complication of uncovered SEMSs. However, because they are prone to migration, the superiority of covered SEMS has yet to be convincingly demonstrated. The aim of this study was to evaluate the superiority of covered over uncovered SEMSs in the palliation of distal biliary obstruction due to unresectable pancreatic carcinoma, using both stent types with relatively low axial force and uncovered flared ends to prevent their migration.METHODS:From April 2009 to December 2010, 120 patients who were admitted to 22 tertiary-care centers because of distal biliary obstruction from unresectable pancreatic carcinomas were enrolled in this prospective randomized multicenter study. Patients were randomly assigned to receive a covered or uncovered SEMS deployed at the site of the biliary stricture during endoscopic retrograde cholangiopancreatography. Stent patency time, patient survival time, patient survival time without stent dysfunction (time to stent dysfunction or patient death), cause of stent dysfunction (ingrowth, overgrowth, migration, or sludge formation), and serious adverse events were compared between covered and uncovered SEMS groups.RESULTS:Patient survival time in the two groups did not significantly differ (median: 285 and 223 days, respectively; P=0.68). Patient survival time without stent dysfunction was significantly longer in the covered than in the uncovered SEMS group (median: 187 vs. 132 days; P=0.043). Stent patency was also significantly longer in the covered than in the uncovered SEMS group (mean±s.d.: 219.3±159.1 vs. 166.9±124.9 days; P=0.047). Reintervention for stent dysfunction was performed in 14 of 60 patients with covered SEMSs (23%) and in 22 of 60 patients with uncovered SEMSs (37%; P=0.08). Stent dysfunction was caused by tumor ingrowth, tumor overgrowth, and sludge formation in 0 (0%), 3 (5%), and 11 (18%) patients in the covered SEMSs group, and in 15 (25%), 2 (3%), and 6 (10%) patients in the uncovered SEMSs group, respectively. Stent migration was not observed in either group. Rates of tumor overgrowth and sludge formation did not significantly differ between the two groups, whereas the rate of tumor ingrowth was significantly lower in the covered than in the uncovered SEMS group (P<0.01). Acute pancreatitis occurred in only one patient in the covered SEMS group. Acute cholecystitis occurred in one patient in the covered SEMS group and in two patients in the uncovered SEMS group. There was no significant difference between the two groups in the incidence of serious adverse events.CONCLUSIONS:By preventing tumor ingrowth and migration, covered SEMSs with an anti-migration system had a longer duration of patency than uncovered SEMSs, which recommends their use in the palliative treatment of patients with biliary obstruction due to pancreatic carcinomas.

The performance of a novel ball-tipped Flush knife for endoscopic submucosal dissection: a case-control study

Aliment Pharmacol Ther 2010; 32: 908–915

THE NEW RESOURCES OF TREATMENT FOR EARLY STAGE COLORECTAL TUMORS: EMR WITH SMALL INCISION AND SIMPLIFIED ENDOSCOPIC SUBMUCOSAL DISSECTION

Introduction:  Early stage colorectal tumors can be removed by endoscopic mucosal resection (EMR) but larger tumors (≧20 mm) may require piecemeal resection. The development of endoscopic submucosal dissection (ESD) has enabled en‐bloc resection of lesions regardless of size and shape. However ESD of colorectal tumor is technically difficult. As the resources, we perform EMR with small incision (EMR with SI) for more reliable EMR, and also ESD with snaring (simplified ESD) for easier and safer ESD.

Predictors of malignant intraductal papillary mucinous neoplasm of the pancreas.

Goals The predictors of malignant intraductal papillary mucinous neoplasm (IPMN) and invasive IPMN were investigated in this study to determine the optimal indicators of surgical resection for IPMN. Background Recently, international consensus guidelines have described the standard indicators of resection for IPMN. However, the indicators of surgical resection for IPMN, especially for branch duct IPMN, still remain controversial. Study Eighty-two patients with IPMN who underwent surgical resection during April 1998 to January 2009, were retrospectively reviewed and examined with regard to their preoperative factors and pathologic diagnosis. Results Multivariate analysis showed that main duct IPMN (P<0.01) and earlier diabetes (P=0.03) were independent predictors of malignant IPMN. In branch duct IPMN, the diameter of the main pancreatic duct (MPD) was found to be significantly associated with malignancy by univariate analysis (P=0.034). An elevated serum CA19-9 level (P<0.01) was an independent predictor of invasive IPMN. Conclusions Our observations suggest that main duct IPMN, branch duct IPMN with MPD dilatation, and IPMN with an elevated serum CA19-9 level should be considered as indications for surgical resection.

Vitamin K3 attenuates cerulein-induced acute pancreatitis through inhibition of the autophagic pathway.

Objectives: The discovery of novel and effective treatment methods would be of great help to patients with acute pancreatitis. The aims of this study were to determine the inhibitory effects of vitamin K3 (VK3) against cerulein-induced acute pancreatitis in mice and to examine the mechanisms behind these effects. Methods: Acute pancreatitis in mice was induced by intraperitoneal injection of cerulein 6 times at hourly intervals. Vitamin K3 was administered once before the first injection of cerulein or twice before and after the first injection of cerulein. The degrees of inflammation and autophagy in the pancreatic tissue were estimated by histological examination, measurement of enzyme activity, confocal microscopy, and Western blotting. The inhibitory effects of VK3 against rapamycin-induced autophagy were also examined using HeLa cells stably expressing green fluorescent protein LC3. Results: Cerulein-induced acute pancreatitis was markedly attenuated by the administration of VK3. In addition, VK3 led to the inhibition of cerulein-evoked autophagic changes and colocalization of autophagosomes and lysosomes in the pancreatic tissue. Vitamin K3 also reduced rapamycin-induced autophagy in HeLa/green fluorescent protein LC3 cells. Conclusions: Our data suggest that the administration of VK3 reduces pancreatic inflammation in acute pancreatitis through inhibition of the autophagic pathway. Vitamin K3 may be an effective therapeutic strategy against acute pancreatitis.

CLINICOPATHOLOGICAL CHARACTERISTICS OF ABNORMAL MICRO‐LESIONS AT THE ORO‐HYPOPHARYNX DETECTED BY A MAGNIFYING NARROW BAND IMAGING SYSTEM

Background:  Narrow band imaging (NBI) with magnifying endoscopy (NBI‐ME) allows the detection of abnormal micro‐lesions smaller than 5 mm in diameter in the oro‐hypopharynx that could not be visualized previously. The purpose of the present study was to clarify the clinicopathological characteristics of abnormal micro‐lesions of the oro‐hypopharynx detected by NBI‐ME

Adherence to the preventive strategies for nonsteroidal anti-inflammatory drug- or low-dose aspirin-induced gastrointestinal injuries.

As the aging of the population advances, the use of nonsteroidal anti-inflammatory drugs (NSAIDs) and/or low-dose aspirin (LDA) is increasing. Their use is accompanied by a risk of serious complications, such as hemorrhage or perforation of the gastrointestinal tract. Therefore, gastroprotective strategies upon the prescription of NSAIDs/LDA are outlined in several guidelines or recommendations. Because all NSAIDs including cyclooxygenase (COX)-2 inhibitors have cardiovascular (CV) toxicity, recent guidelines are based on not only GI risks but also CV risks of NSAID users. Assessment of the adherence to evidence-based guidelines or recommendations for the safe prescription of NSAIDs/LDA in clinical practice is an important issue. Here, we summarize randomized controlled trials (RCTs) on the preventive effects of antisecretory drugs for NSAID- or LDA-induced peptic ulcers. Then, we describe preventive strategies upon the prescription of NSAIDs/LDA outlined in several guidelines or recommendations, and describe studies on adherence and outcomes of adherence to these preventive strategies. Finally, we discuss strategies to increase the adherence rate, and changing pattern of GI events associated with NSAIDs/LDA. In Japan, the preventive strategies upon the prescription of NSAIDs/LDA are expected to spread rapidly because the use of proton pump inhibitors for the prevention of recurrence of NSAID- or LDA-induced peptic ulcers and the use of COX-2 for the palliation of acute pain were recently approved under the national health insurance system. Further studies on adherence to the preventive strategies and the outcomes of adherence, which include both GI events and CV events, in the Japanese population are required.

What is the most adapted indication of prophylactic pancreatic duct stent within the high‐risk group of post‐endoscopic retrograde cholangiopancreatography pancreatitis? Using the propensity score analysis

Conducting randomized controlled trial (RCT) for each of the risk factors associated with prophylactic pancreatic duct stent (PPDS) for post‐endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) is difficult owing to the volume of cases and ethical considerations. In this study, we tried to reveal the degree of preventive effects of PPDS for each individual risk factor within the high‐risk group of PEP using the propensity score analysis.

Double immunostaining for maspin and p53 on cell blocks increases the diagnostic value of biliary brushing cytology

Our objective is to elucidate the usefulness of maspin/p53 double immunostaining on biliary brushing cytology specimens. We first examined the expression of maspin in the biliary epithelium with variable degrees of dysplasia using surgically resected specimens (n = 56). Maspin appeared to be overexpressed in a stepwise manner from benign to malignant cholangiocytes: the reactive epithelium (20%), biliary intraepithelial neoplasia (~50%), and invasive cholangiocarcinomas (>90%). Next, an automated sequential double immunostaining protocol for maspin and p53 was applied to paraffin‐embedded cell blocks of the biliary brushing cytology specimens obtained from 58 consecutive patients. Cell block preparation was successful in 44 cases (76%), which were morphologically diagnosed as adenocarcinoma (n = 16), atypical cells not diagnostic for malignancy (n = 10), and benign (n  = 18). Double positive cells were observed in 14/16 (88%) morphologically malignant, 6/10 (60%) borderline, and 0/18 benign cases. All 20 positive cases were proven to have pancreatobiliary malignancies by subsequent imaging or pathological analyses. A similar staining protocol for S100P and p53 was also applied to the same cohort; however, the positive frequency was slightly lower than those of maspin and p53 (36% vs. 45%). In conclusion, Maspin/p53 double immunostaining on cell blocks contributes to the detection of malignant cells in biliary brushing cytology specimens.