Masatsugu Nagahama

Multicenter study of endoscopic preoperative biliary drainage for malignant distal biliary obstruction.

AIM To determine the optimal method of endoscopic preoperative biliary drainage for malignant distal biliary obstruction. METHODS Multicenter retrospective study was conducted in patients who underwent plastic stent (PS) or nasobiliary catheter (NBC) placement for resectable malignant distal biliary obstruction followed by surgery between January 2010 and March 2012. Procedure-related adverse events, stent/catheter dysfunction (occlusion or migration of PS/NBC, development of cholangitis, or other conditions that required repeat endoscopic biliary intervention), and jaundice resolution (bilirubin level < 3.0 mg/dL) were evaluated. Cumulative incidence of jaundice resolution and dysfunction of PS/NBC were estimated using competing risk analysis. Patient characteristics and preoperative biliary drainage were also evaluated for association with the time to jaundice resolution and PS/NBC dysfunction using competing risk regression analysis. RESULTS In total, 419 patients were included in the study (PS, 253 and NBC, 166). Primary cancers included pancreatic cancer in 194 patients (46%), bile duct cancer in 172 (41%), gallbladder cancer in three (1%), and ampullary cancer in 50 (12%). The median serum total bilirubin was 7.8 mg/dL and 324 patients (77%) had ≥ 3.0 mg/dL. During the median time to surgery of 29 d [interquartile range (IQR), 30-39 d]. PS/NBC dysfunction rate was 35% for PS and 18% for NBC [Subdistribution hazard ratio (SHR) = 4.76; 95%CI: 2.44-10.0, P < 0.001]; the pig-tailed tip was a risk factor for PS dysfunction. Jaundice resolution was achieved in 85% of patients and did not depend on the drainage method (PS or NBC). CONCLUSION PS has insufficient patency for preoperative biliary drainage. Given the drawbacks of external drainage via NBC, an alternative method of internal drainage should be explored.

Small Intestinal Obstruction Caused by Anisakiasis

Small intestinal anisakiasis is a rare disease that is very difficult to diagnose, and its initial diagnosis is often surgical. However, it is typically a benign disease that resolves with conservative treatment, and unnecessary surgery can be avoided if it is appropriately diagnosed. This case report is an example of small intestinal obstruction caused by anisakiasis that resolved with conservative treatment. A 63-year-old man admitted to our department with acute abdominal pain. A history of raw fish (sushi) ingestion was recorded. Abdominal CT demonstrated small intestinal dilatation with wall thickening and contrast enhancement. Ascitic fluid was found on the liver surface and in the Douglas pouch. His IgE (RIST) was elevated, and he tested positive for the anti-Anisakis antibodies IgG and IgA. Small intestinal obstruction by anisakiasis was highly suspected and conservative treatment was performed, ileus tube, fasting, and fluid replacement. Symptoms quickly resolved, and he was discharged on the seventh day of admission. Small intestinal anisakiasis is a relatively uncommon disease, the diagnosis of which may be difficult. Because it is a self-limiting disease that usually resolves in 1-2 weeks, a conservative approach is advisable to avoid unnecessary surgery.

Study on Clinical Factors Involved in Helicobacter pylori-Uninfected, Undifferentiated-Type Early Gastric Cancer

Background: The factors associated with the pathogenesis of Helicobacter pylori-uninfected undifferentiated-type early gastric cancer (HPUGC) remain unclear. This study compared patient characteristics, including medical history and alcohol/tobacco use, of HPUGC patients with characteristics of patients with H. pylori-positive undifferentiated-type early gastric cancer (HPPGC) to clarify and gain understanding on those differences that could play a role in the pathogenesis. Methods: This retrospective study included 282 patients who were treated endoscopically from March 2005 to March 2014. This cohort consisted of 232 patients with HPPGC (82.3%) and 50 patients with HPUGC (17.7%). Patient characteristics were analyzed by subgroups of HPUGC vs. HPPGC, with comparisons for age, gender, cancer history, comorbidity of lifestyle diseases requiring medication (hypertension, type 2 diabetes, and dyslipidemia), cumulative amount of alcohol consumption, and smoking history (Brinkman index [BI]). Results: HPUGC patients were typically younger, had less frequent hypertension, and had higher BI values (p < 0.05 for all parameters). In a younger non-hypertensive subgroup, the OR for high BI (BI ≥340) in the HPUGC group vs. HPPGC group was 5.049 (95% CI 2.458–10.373, p < 0.0001). Conclusions: The investigation of clinical factors identified smoking history as being possibly contributing to the pathogenesis of HPUGC. Future research is necessary at the cellular and genetic levels.

Successful Conservative Treatment of Emphysematous Gastritis

Emphysematous gastritis is an extremely rare disease with an unfavorable prognosis. To date, very few studies have been conducted regarding the intragastric recovery process based on endoscopic findings. We herein report a case of emphysematous gastritis that improved with long-term (five months) conservative treatment in which we were able to observe the intragastric recovery process endoscopically. In cases in which emphysematous gastritis is suspected, it is important to provide prompt diagnostic imaging (including CT) and early appropriate treatment in order to improve the prognosis.

Undifferentiated-type component mixed with differentiated-type early gastric cancer is a significant risk factor for endoscopic non-curative resection

Previous studies of surgical specimens have found that the presence of mixed histological components in differentiated‐type early gastric cancer (EGC) is a risk factor for lymph node metastasis and indicates greater malignancy. As there have been no reports on its endoscopic treatment, we examined endoscopic curative resection in relation to differentiated‐type‐predominant mixed‐type (MT).

Plastic (Tube) Stent Drainage

Endoscopic biliary drainage using a plastic stent (PS) has been widely performed for endoscopic treatment of cholangitis and jaundice due to biliary obstruction. However, subsequent studies comparing PS and self-expandable metallic stent (SEMS) demonstrated the superiority of SEMS in the treatment of unresectable malignant biliary obstruction. Thus, good candidates for endoscopic biliary drainage with a PS are now considered to include emergency drainage for acute cholangitis, drainage for benign biliary stricture, temporary drainage for obstructive jaundice during diagnostic differentiation of benign from malignant lesions, and stent-in-stent placement for SEMS obstruction. On the other hand, a new effort to place a stent that is called “inside stent” has been reported. The “inside-stent” technique has recently been reported to be useful for the treatment of benign biliary stricture after hepatic transplantation and unresectable malignant hilar biliary obstruction. Future studies on the “inside-stent” technique are warranted.

Multicenter study of endoscopic preoperative biliary drainage for malignant hilar biliary obstruction: E-POD hilar study: Preoperative hilar biliary drainage

Endoscopic nasobiliary drainage (ENBD) is often recommended in preoperative biliary drainage (PBD) for hilar malignant biliary obstruction (MBO), but endoscopic biliary stent (EBS) is also used in the clinical practice. We conducted this large‐scale multicenter study to compare ENBD and EBS in this setting.

Diagnostic accuracy of demarcation using magnifying endoscopy with narrow-band imaging for Helicobacter pylori-uninfected undifferentiated-type early gastric cancer

BackgroundIt is unknown how the accuracy rate of diagnostic demarcation of undifferentiated-type early gastric cancers (UD-type EGCs) differs between patients uninfected with Helicobacter pylori (H. pylori) and patients with and without H. pylori eradication. This study assessed and compared the diagnostic accuracy rate in the H. pylori-uninfected group and the non-H. pylori eradication and H. pylori eradication groups.MethodsSubjects were 81 patients with 81 lesions who underwent endoscopic submucosal dissection between January 2010 and January 2015. There were 21 lesions in the H. pylori-uninfected group, 27 in the H. pylori eradication group, and 33 in the non-H. pylori eradication group. The rate in the H. pylori-uninfected group was separately compared with the rates in the non-H. pylori eradication and H. pylori eradication groups, as was inflammatory cell infiltration.ResultsThe diagnostic accuracy rates were 60.6% in the non-H. pylori eradication group, 92.2% in the H. pylori eradication group, and 100% in the H. pylori-uninfected group; the rate was significantly higher in the H. pylori-uninfected group than in the non-H. pylori eradication group, but no significant difference was observed between the H. pylori-uninfected group and the H. pylori eradication group. In addition, the H. pylori-uninfected and H. pylori eradication groups showed no significant differences in neutrophil infiltration and intestinal metaplasia, whereas the state in the H. pylori-uninfected group was significantly milder.ConclusionsBecause neutrophil infiltration was classified as mild or none, the accuracy of diagnostic demarcation was high in the H. pylori-uninfected and H. pylori eradication groups.

Mixed poorly differentiated adenocarcinoma in undifferentiated-type early gastric cancer predicts endoscopic noncurative resection

BackgroundComparisons between surgical cases of mixed poorly differentiated adenocarcinoma and pure signet ring cell carcinoma have revealed higher frequencies of lymph node metastasis and submucosal invasion in the former. However, this comparison has not been reported for endoscopically treated cases. Therefore, we compared cases of curative and noncurative resection in patients who underwent endoscopic submucosal dissection to determine what factors could influence the curative resection rate.MethodsWe analyzed 268 undifferentiated-type early gastric cancers in 264 patients treated with endoscopic submucosal dissection in our hospital between March 2005 and March 2017, involving 229 and 39 cases of curative and noncurative resection, respectively. Treatment results were compared between 129 lesions of pure signet ring cell carcinoma and 139 lesions of mixed poorly differentiated adenocarcinoma.ResultsThe overall curative resection rate was 85.4% (229/268). On comparing noncurative and curative resection cases, after excluding factors that determine curative resection (e.g., tumor diameter), we found that the former was associated with older age and significantly more mixed poorly differentiated adenocarcinomas, with odds ratios of 1.052 [95% confidence interval (CI), 1.017–1.089] and 2.746 (95% CI, 1.162–6.485), respectively, on multivariate analysis. The curative resection rate was significantly higher in pure signet ring cell carcinoma than in mixed poorly differentiated adenocarcinoma (93.8% vs. 77.7%, respectively).ConclusionAdvanced age and mixed poorly differentiated adenocarcinoma predicted endoscopic noncurative resection.

Optimal timing for precutting in cases with difficult biliary cannulation

Background and study aims  In endoscopic retrograde cholangiopancreatography (ERCP), precutting is widely used when achieving biliary cannulation is difficult. However, no consensus has been reached with regard to the best time to initiate precutting. Patients and methods  We retrospectively examined 63 patients who underwent precutting for naïve papilla with difficulty in biliary cannulation between 2009 and 2016. The outcomes of the early precut group (≤ 20 min from cannulation until initiating precutting) and the late precut group (> 20 min) were compared. Results  Of the 63 patients, 17 (27 %) were in the early precut group and 46 (73 %) were in the late precut group; median time until the initiating precutting was 28 minutes (7 – 50). No significant difference was observed between the two groups in terms of clinical features (age, sex, and indication for ERCP), precutting method, and rate of pancreatic duct stent placement. Significantly higher rates of successful biliary cannulation were observed in the early precut group (16/17; 94 %) than in the late precut group (32/46; 70 %) ( P  < 0.05). In 13 patients in whom precutting was commenced after 40 minutes, the rate of successful biliary cannulation was very low at 53 % (7/13). No significant difference was found between the two groups in terms of incidence of complications (pancreatitis in 5 patients and bleeding in 1 patient). Conclusion  In actual clinical practice, precutting is commenced approximately 30 minutes after cannulation; however, to successfully achieve biliary cannulation, precutting is recommended to be performed within 20 minutes. Precutting is effective when little inflammation and swelling of the ampulla of Vater is observed. This study was limited in that it was single-center, retrospective and had a small subject sample.