Objective To investigate the feasibility and safety of endoscopic ultrasonography (EUS) guided interstitial chemotherapy for the pancreas in canine model. Methods A therapeutic 19gauge needle was inserted into the pancreas with EUS guidance,and seeds with sustained release of 5-iluorouracil were implanted into the tissue. After 14 days of clinical observation,the animals were sacrificed and the tissue response to local chemotherapy was examined. Results All the seeds were implanted successfuUy and no migration was observed. Chemotherapy induced tissue fibrous necrosis was localized in the pancreas without significant complications. The apoptotic index of tissue within 1 cm of the seeds increased.Biochemical parameters were normal in all the dogs. Conclusion EUS-guided implantation of seeds is a safe,simple and minimally invasive technique for interstitial chemotherapy in the pancreas.

Objective To evaluate the diagnostic value of endoscopic ultrasonic elastography in lymph node staging of gastrointestinal tumors.Methods Thirty-nine abdominal lymph nodes and 26 mediastinal lymph nodes of 35 patients with gastric cancer or esophageal carcer were examined by endoscopic ultrasonic elastography of five-point elastic score.Lymph node at 1-3 points was regarded as negative(benign),while 4-5 points as positive(malignant).The diagnostic value of EUS elastography was determined by comparing the results with pathological findings.Results Of all the 65 lymph nodes,49 were diagnosed as positive and 16 negative.The sensitivity and specificity of EUSE in the diagnosis of malignant lymph nodes were 91.1%and 60.0%.respectively.Conclusion EUSE is helpful for diagnosis of malignant metastasic lymph nodes.

Objective To investigate the differences of EUS images between stromal tumors and leiomyoma in esophagus and cardia. Methods EUS image of 13 cases of stromal tumors and 11 cases of leiomyoma diagnozed immunohistochemically were collected. Information of gray scale including mean value and dissociation of lesions and submucosal layer were analyzed. Gray scale values of lesions were calibrated according to that of the submucosal layer. Results The mean value of corrected gray scale of stromal tumors was 0. 285, which was significantly different from that of leiomyoma (0. 185, P ＜ 0. 05). Dissociation of gray scale of stromal tumors was 8. 14, which was also significantly different from that of leiomyomia (4. 59,P ＜0. 05). Conclusion In esophagus and cardia, stromal tumors exhibits higher and more inhomogeneous ultrasound echo than leiomyoma.

Objective To evaluate the therapeutic value of endoscopic band ligation in gastric stromal tumors.Methods Twenty-nine patients with small gastric stromal tumors(diameter<12mm)underwent endoscopic band ligation,and were followed up with routine endoscopy and EUS.Results Twentyeight patients recovered completely,with the surface healing up 4-6 weeks(average 4.8 weeks)thereafter.The neoplasm did not slough off in one patient,so he underwent a second ligation.Hemorrhage occurred in one patient three days after ligation,but was successfully managed with hemoclips.Other patients showed no complications.All the patients were followed up for 36 to 51 months,and there was one case of recurrence.Conclusion Endoscopic band ligation is an effective and safe treatment for small GISTs of less than 12 mm.

Objective To investigate the optimal time for double balloon enteroscopy (DBE) in patients with obscure gastrointestinal bleeding (OGIB).Methods Data of 78 patients with OGIB who underwent DBE from January 2009 to November 2013 were retrospectively analyzed.They were classified into two groups:emergency DBE and non-emergency DBE.The demographic and clinical features and outcomes of DBE,the time of examination and complications were compared.Results The overall diagnostic yield of DBE was 48 lesions (61.54 ％).The overall diagnostic yield of emergency DBE group was 77.14％,which was significantly higher than that in non-emergency DBE group (48.83％) (P =0.019).The time of examination in emergency group was shorter than that of non-emergency group with significant difference (P =0.031).Conclusion Emergency DBE takes less time and yields a higher rate of detection.Patients withOGIB should receive DBE as soon as possible.

Objective To evaluate the clinical effects and safety of double-channel forward-view endoscopy for lower-position biliary obstruction after Billroth-Ⅱ gastrectomy.Methods A total of 18 patients with lower-position biliary obstruction after Billroth-Ⅱ gastrectomy were enrolled and treated with doublechannel forward-view endoscopy.The process and the outcomes were recorded.Effectiveness and safety were evaluated.Results Double-channel forward-view endoscopic treatment was successfully performed in 13 of the 18 patients (72％),with stone removal or stents implantion to resolve biliary obstruction.The procedure failed in 5 patients,who were transferred to surgery or underwent percutaneous transhepatic cholangial drainage.Delayed bleeding occurred in 1 patient,and pancreatitis in 2,who were cured after standard treatments.Conclusion Double-channel forward-view endoscopy is effective and safe for lower-position biliary obstruction in patients after Billroth-Ⅱ gastrectomy.

Objective To evaluate the short-term safety and efficacy of endoscopic implantation of self-expandable metallic stent (SEMs) for malignant colorectal obstruction.Methods A total of 208 patients who had undergone endoscopic SEMs implantation for malignant colonic obstruction from January 2012 to May 2014 at the endoscopy center of Shengjing hospital were enrolled.The technical and clinical success rate and the complications were reviewed.Results The technical and clinical success rates were 99.04％ (206/208) and 96.15％ (200/208), respectively.Abdominal pain, perforation and bleeding were the most common post-procedure complications, the rates of which were 13.46％ (28/208), 2.88％ (6/208), 1.92％ (4/208), respectively.The abdominal pain in most patients was self-relieving except for 6 patients with perforation of colon.Patients with perforation were cured by emergency surgery.One patient with intraperitoneal hemorrhage was also cured by emergency surgery, the other patients developing bleeding recovered themselves.Conclusion The success rate of endoscopic SEMs implantation is satisfactory in the study.As a bridge to surgery or a palliative care method, endoscopic SEMs implantation is effective and safe for malignant colorectal obstruction.

Objective To investigate the incidence of electrocoagulation syndrome after endoscopic submucosal dissection (ESD) in the colorectal laterally spreading tumors (LST) and the risk factors. Methods Data of 51 patients with coloretral LST,treated with ESD from January 2010 to May 2014 at Shengjing hospital affiliated to China Medical University,were reviewed.The incidence of electrocoagulation syndrome was analyzed and logistic regression was used to evaluate risk.Results The incidence of electro-coagulation syndrome was 9.8%(5 /51).The incidence of tumors in the rectal area(7.1%,2 /28)was lower than that of the left half colon (12.5%,1 /8),and the right colon (13.3%,2 /15).Multivariable logistic regression analysis showed that the independent risk factors for the development of electrocoagulation syndrome were LST located in non-rectum area (OR =1.655,P <1.655),lesion size larger than 25 mm (OR =1.028, P <0.05),the operation time longer than 129 min (OR =1.016,P <0.05),age older than 62 year old (OR =0.987,P <0.05).Conclusion For the patients aged over 62 year old,lesion size larger than 25 mm,the operation time longer than 129 min and LST located outside the rectum,the mucous membrane should be separated from the muscularis propria in the ESD procedure to reduce electrocoagulation time as much as possible. In the postoperative period,patients need fasting,fluid replacement support,and prevention of post endoscopic submucosal dissection electrocoagulation syndrome (PEECS).

Objective To evaluate the efficacy of endoscopic metal stent implantation for afferent limb obstruction after pancreaticoduodenectomy(PD). Methods A retrospective analysis of 5 patients with afferent limb obstruction after PD treated by endoscopic metal stent implantation was performed.Data of each patient was reviewed including the records of the endoscopic procedure,the complications and the clinical outcomes. Results All the metal stents were implanted successfully in the 5 patients. The abdominal disten-sion and cholangeitis were well relieved in all the patients. The liver function improved in all the patients in 3 to 5 days.No abdominal discomfort,bleeding,perforation,or stent dislocation occurred.CT scan showed that all stents were well expanded.The survival time of the 5 patients were 3 to 8 months,and 4. 6 months on av-erage. There was no recurrence of afferent limb obstruction. Conclusion For afferent limb obstruction after PD,endoscopic metal stent implantation is effective in relieving obstruction,the symptoms,and improving the quality of life.

Objective To investigate whether preoperative proton pump inhibitor (PPI) would increase the risk of bacteremia after endoscopic ultrasonography guided fine needle aspiration (EUS-FNA).Methods Dogs were randomly divided into experimental group ( n = 8) to take 20mg of omeprazole orally twice a day for 3 days before EUS-FNA, and control group (n = 10) to take placebo.EUS-FNA was performed to puncture the pancreas, and blood was collected before and after the procedure for culture.Bacteremia incidence of the two groups were compared.Results Bacteria culture was positive in 11 edogse.After excluding contamination, 1 dog in experimental group and 3 in control group were authentical bacteremia.There was no significant difference on the incidence of bacteremia between 2 groups based on Fisher test ( P = 0.383).Conclusion Aplication of PPI before EUS-FNA is not likely to increase the incidence of bacteremia.